Article

Frequencies and expression levels of programmed death ligand 1 (PD-L1) in circulating tumor RNA (ctRNA) in various cancer types

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Abstract

Background: Precision medicine and prediction of therapeutic response requires monitoring potential biomarkers before and after treatment. Liquid biopsies provide noninvasive prognostic markers such as circulating tumor DNA and RNA. Circulating tumor RNA (ctRNA) in blood is also used to identify mutations in genes of interest, but additionally, provides information about relative expression levels of important genes. In this study, we analyzed PD-L1 expression in ctRNA isolated from various cancer types. Tumors inhibit antitumor response by modulating the immune checkpoint proteins programmed death ligand 1 (PD-L1) and its cognate receptor PD1. The expression of these genes has been implicated in evasion of immune response and resistance to targeted therapies. Methods: Blood samples were collected from gastric (GC), colorectal (CRC), lung (NSCLC), breast (BC), prostate cancer (PC) patients, and a healthy control group. ctRNA was purified from fractionated plasma, and following reverse transcription, levels of PD-L1 expression were analyzed using qPCR. Results: PD-L1 expression was detected in the plasma ctRNA of all cancer types at varying frequencies but no PD-L1 mRNA was detected in cancer-free individuals. The frequencies of PD-L1 expression were significantly different among the various cancer types but the median relative PD-L1 expression values were not significantly different. In 12 cases where plasma and tumor tissue were available from the same patients, there was a high degree of concordance between expression of PD-L1 protein in tumor tissues and PD-L1 gene expression in plasma, and both methods were equally predictive of response to nivolumab. Conclusions: PD-L1 mRNA can be detected and quantitated in ctRNA of cancer patients. These results pave the way for further studies aimed at determining whether monitoring the levels of PD-L1 mRNA in blood can identify patients who are most likely to benefit from the conventional treatment.

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... Few articles evaluated PD-L1 expression by tumor and/or inflammatory cells in blood samples of PC patients [11,14,16,20,23,45,54,64,87,88,91,96,97,101,147]. ...
... Despite that it was not clearly stated, PD-L1 expression seemed not to correlate with OS. Table 2 summarizes the few articles reporting some information about the role of ctRNA or exosomes in PD-L1 expression among PC patients [11,14,23,64]. Despite that ctRNA is more unstable than ctDNA in biological fluids (probably because of ribonucleases), some authors managed to isolate ctRNA of various cancer patients (prostatic, colic, gastric, and pulmonary carcinomas) by using RT-PCR [64]. ...
... Table 2 summarizes the few articles reporting some information about the role of ctRNA or exosomes in PD-L1 expression among PC patients [11,14,23,64]. Despite that ctRNA is more unstable than ctDNA in biological fluids (probably because of ribonucleases), some authors managed to isolate ctRNA of various cancer patients (prostatic, colic, gastric, and pulmonary carcinomas) by using RT-PCR [64]. Indeed, Ishiba et al. found ctRNA in the plasma of 21/88 (24%) PC patients by RT-PCR, while no PD-L1 mRNA was detected in cancer-free men (0/19, 0%); outcome correlation was not performed [64]. ...
Article
Liquid biopsy is an accessible, non-invasive diagnostic tool for advanced prostate cancer (PC) patients, potentially representing a real-time monitoring test for tumor evolution and response to treatment through the analysis of circulating tumor cells (CTCs) and exosomes. We performed a systematic literature review (PRISMA guidelines) to describe the current knowledge about PD-L1 expression in liquid biopsies of PC patients: 101/159 (64%) cases revealed a variable number of PD-L1+ CTCs. Outcome correlations should be investigated in larger series. Nuclear PD-L1 expression by CTCs was occasionally associated with worse prognosis. Treatment (abiraterone, enzalutamide, radi-otherapy, checkpoint-inhibitors) influenced PD-L1+ CTC levels. Discordance in PD-L1 status was detected between primary vs. metastatic PC tissue biopsies and CTCs vs. corresponding tumor tissues. PD-L1 is also released by PC cells through soluble exosomes, which could inhibit the T cell function, causing immune evasion. PD-L1+ PC-CTC monitoring and genomic profiling may better characterize the ongoing aggressive PC forms compared to PD-L1 evaluation on primary tumor biopsies/prosta-tectomy specimens (sometimes sampled a long time before recurrence/progression). Myeloid-derived suppressor cells and dendritic cells (DCs), which may have immune-suppressive effects in tumor mi-Citation: Palicelli, A.; Bonacini, M.; Croci, S.; Bisagni, A.; Zanetti, E.; De Biase, D.; Sanguedolce, F.; Ragazzi, M.; Zanelli, M.; Chaux, A.; et al. What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 7: PD-L1 Expression in Liquid Biopsy.
... Few articles evaluated PD-L1 expression by tumor and/or inflammatory cells in blood samples of PC patients [11,14,16,20,23,45,54,64,87,88,91,96,97,101,147]. ...
... Despite that it was not clearly stated, PD-L1 expression seemed not to correlate with OS. Table 2 summarizes the few articles reporting some information about the role of ctRNA or exosomes in PD-L1 expression among PC patients [11,14,23,64]. ...
... Despite that ctRNA is more unstable than ctDNA in biological fluids (probably because of ribonucleases), some authors managed to isolate ctRNA of various cancer patients (prostatic, colic, gastric, and pulmonary carcinomas) by using RT-PCR [64]. Indeed, Ishiba et al. found ctRNA in the plasma of 21/88 (24%) PC patients by RT-PCR, while no PD-L1 mRNA was detected in cancer-free men (0/19, 0%); outcome correlation was not performed [64]. ...
Article
Full-text available
Liquid biopsy is an accessible, non-invasive diagnostic tool for advanced prostate cancer (PC) patients, potentially representing a real-time monitoring test for tumor evolution and response to treatment through the analysis of circulating tumor cells (CTCs) and exosomes. We performed a systematic literature review (PRISMA guidelines) to describe the current knowledge about PD-L1 expression in liquid biopsies of PC patients: 101/159 (64%) cases revealed a variable number of PD-L1+ CTCs. Outcome correlations should be investigated in larger series. Nuclear PD-L1 expression by CTCs was occasionally associated with worse prognosis. Treatment (abiraterone, enzalutamide, radi-otherapy, checkpoint-inhibitors) influenced PD-L1+ CTC levels. Discordance in PD-L1 status was detected between primary vs. metastatic PC tissue biopsies and CTCs vs. corresponding tumor tissues. PD-L1 is also released by PC cells through soluble exosomes, which could inhibit the T cell function, causing immune evasion. PD-L1+ PC-CTC monitoring and genomic profiling may better characterize the ongoing aggressive PC forms compared to PD-L1 evaluation on primary tumor biopsies/prosta-tectomy specimens (sometimes sampled a long time before recurrence/progression). Myeloid-derived suppressor cells and dendritic cells (DCs), which may have immune-suppressive effects in tumor mi-Citation: Palicelli, A.; Bonacini, M.; Croci, S.; Bisagni, A.; Zanetti, E.; De Biase, D.; Sanguedolce, F.; Ragazzi, M.; Zanelli, M.; Chaux, A.; et al. What Do We Have to Know about PD-L1 Expression in Prostate Cancer? A Systematic Literature Review. Part 7: PD-L1 Expression in Liquid Biopsy.
... Plasma mRNA markers with predictive value for therapy response were also investigated [166,167]. Pucciarelli et al. established that cell-free RNA and hTERT mRNA levels in plasma samples of rectal cancer patients can predict the tumor response to preoperative chemoradiotherapy [166]. The results of a recent large multi-cancer RT-qPCR study including 212 CRC samples suggest that analysis of programmed death ligand 1 (PD-L1) mRNA expression in plasma may be suitable method for detecting the presence of cancer [167]; however, its efficiency for prediction of response to nivolumab treatment was studied and shown in non-small cell lung cancer in this project [167]. ...
... Pucciarelli et al. established that cell-free RNA and hTERT mRNA levels in plasma samples of rectal cancer patients can predict the tumor response to preoperative chemoradiotherapy [166]. The results of a recent large multi-cancer RT-qPCR study including 212 CRC samples suggest that analysis of programmed death ligand 1 (PD-L1) mRNA expression in plasma may be suitable method for detecting the presence of cancer [167]; however, its efficiency for prediction of response to nivolumab treatment was studied and shown in non-small cell lung cancer in this project [167]. Table 3 summarizes the blood mRNA biomarkers of CRC (Table 3). ...
... Pucciarelli et al. established that cell-free RNA and hTERT mRNA levels in plasma samples of rectal cancer patients can predict the tumor response to preoperative chemoradiotherapy [166]. The results of a recent large multi-cancer RT-qPCR study including 212 CRC samples suggest that analysis of programmed death ligand 1 (PD-L1) mRNA expression in plasma may be suitable method for detecting the presence of cancer [167]; however, its efficiency for prediction of response to nivolumab treatment was studied and shown in non-small cell lung cancer in this project [167]. Table 3 summarizes the blood mRNA biomarkers of CRC (Table 3). ...
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Introduction: Screening methods for one of the most frequently diagnosed malignancy, colorectal cancer (CRC), have limitations. Circulating cell-free nucleic acids (cfNA) hold clinical relevance as screening, prognostic and therapy monitoring markers. Area covered: In this review, we summarize potential CRC-specific cfNA biomarkers, the recently developed sample preparation techniques, their applications, and pitfalls. Expert opinion: Automated extraction of cfDNA is highly reproducible, however, cfDNA yield is less compared to manual isolation. Quantitative and highly sensitive detection techniques (digital PCR, NGS) can be applied to analyse genetic and epigenetic changes. Detection of DNA mutations or methylation in cfDNA and related altered levels of mRNA, miRNA, and lncRNA may improve early cancer recognition, based on specific, CRC-related patterns. Detection of cfDNA mutations (e.g. TP53, KRAS, APC) has limited diagnostic sensitivity (40-60%), however, methylated DNA including SEPT9, SFRP1, SDC2 can be applied with higher sensitivity (up to 90%) for CRC. Circulating miRNAs (e.g. miR-21, miR-92, miR-141) provide comparably high sensitivity for CRC as the circulating tumor cell mRNA markers (e.g. EGFR, CK19, CK20, CEA). Automation of cfNA isolation coupled with quantitative analysis of CRC-related, highly sensitive biomarkers may enhance CRC screening and early detection in the future.
... Individual response, besides K-ras status and SMAD status is now also a prognosticator for the benefit of downstaging/resection, ALPPS or orthotopic liver transplantation in CRLM [9, 64,67] . To our knowledge, up to now there is no test to individually select effective chemotherapeutic drugs for systemic chemotherapy, but research is ongoing [68,69]. ...
... Most importantly, in cooperation with Danenberg P and Danenberg K we obtained evidence, that TS-and DPDH-expressions seemed to be predictors of survival of the FOGT-1 + 2 patients [26]. In the meantime, we and many others have tried to define a reliable test of either single or a combination of parameters for personalization of multimodal therapy [68,69]. Up to now, only the MSI-status is influencing the decision for multimodal therapy in the S3 guidelines [2]. ...
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Rarely, scientific developments centered around the patient as a whole are published. Our multidisciplinary group, headed by gastrointestinal surgeons, applied this research philosophy considering the most important aspects of the diseases "colon- and rectal cancer" in the long-term developments. Good expert cooperation/knowledge at the Comprehensive Cancer Center Ulm (CCCU) were applied in several phase III trials for multimodal treatments of primary tumors (MMT) and metastatic diseases (involving nearly 2000 patients and 64 centers), for treatment individualization of MMT and of metastatic disease, for psycho-oncology/quality of life involving the patients' wishes, and for disease prevention. Most of the targets initially were heavily rejected/discussed in the scientific communities, but now have become standards in treatments and national guidelines or are topics in modern translational research protocols involving molecular biology for e.g., "patient centered individualized treatment". In this context we also describe the paths we had to tread in order to realize our new goals, which at the end were highly beneficial for the patients from many points of view. This description is also important for students and young researchers who, with an actual view on our recent developments, might want to know how medical progress was achieved.
... 2,3 PD-L1 is expressed by various cancers, including solid tumors and lymphomas, with expression of PD-L1 reportedly being associated with a poorer prognosis. [4][5][6][7] The interplay between cancer cells and the tumor microenvironment has generated interest in the PD1/PD-L1 pathway as a potential therapeutic target for personalized medicine. Further, blockade of PD1 and its ligand PD-L1 has proved effective for the treatment of B-cell lymphomas. ...
... 37 Combination of precision medicine and immunotherapy takes individual variability into account in order to design personalized treatment strategies. 7 In future, more studies on JAK pathway inhibitors as well as anti-PD1 will be conducted synergistically in NKTL. ...
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Purpose: NK/T-cell neoplasms are rare, highly aggressive, and insensitive to chemotherapy. These lymphomas have a poor prognosis, with patients being vulnerable to relapse. Hence, there is a need for alternative treatments. The purpose of this study is to investigate whether anti-PD1 takes effect on NK/T cell lymphoma. Methods: The expression of PD-L1 in NK/T cell lines was investigated by flow cytometry and by Western blot. In vivo, overall survival and median survival time of mice bearing an NK/T cell line tumor was assessed. Tumor-infiltrating T cells and monocyte-derived suppressor cells were evaluated by flow cytometry. Levels of PD-L1 and components of the JAK-STAT pathway were assessed in tumor tissues by immunohistochemistry. Results: NK/T cell lines had greater expression of PD-L1 than normal peripheral blood human NK cells. In vivo, anti-PD1 treatment improved overall survival and median survival time of mice bearing an NK/T cell line. Furthermore, anti-PD1 treatment increased levels of PD-L1. Cultured tumor-infiltrating lymphocytes from mice treated with anti-PD1 had greater levels of IFN-γ than cultured lymphocytes from untreated animals. Further, levels of JAK2 and STAT1 were greater in mice treated with anti-PD1. Conclusion: In vivo, anti-PD1 inhibited the progression of an NK/T-cell lymphoma and up-regulated PD-L1 expression. This up-regulation may be through the IFN-γ-associated JAK-STAT pathway.
... Indeed, Joncas et al [48] recently found blood levels of AR-V7 mRNA, which was shown to be correlated with response and resistance to abiraterone in mCRPC patients, demonstrating its potential as predictive biomarker [48] . Particularly worthy of note, upregulation of the programmed death-ligand PD-L1 mRNA causes cancer cells to able to evade the host immune system [50] . ...
... In PCa samples miR-20A was significantly upregulated compared to healthy controls. On the other hand, there was no significant difference in the levels of pre-and postoperation miR-26A compared to controls Ishiba et al [50] , Aggressiveness of PCa could be segregated based on circulating miRNA signature consisting of an interaction between a combination of two miRNAs (miR-17/miR-192) and an independent miRNA (miR-181a) ...
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Metastatic castrate-resistant prostate cancer remains a disease hard to cure, and for this reason predictive tools to monitor disease progression and therapy response are an urgent need. In this respect, liquid biopsy on circulating cell-free nucleic acids represents an interesting strategy based on robust data. The low invasiveness and the possibility to target circulating cell-free tumor deoxyribonucleic acid underline the high specificity, sensitivity and clinical usability of the technique. Moreover, it has been observed that the cell-free tumor deoxyribonucleic acid of metastatic castrate-resistant prostate cancer patients can be representative of the tumor heterogeneity. Cell-free tumor deoxyribonucleic acids express the same behaviors as mutations: Variation in gene copy number or the methylation rate of the tumor tissue. Recently, circulating cell-free ribonucleic acid molecules have emerged as interesting markers to stratify the disease. Due to high-throughput technologies, liquid biopsy on circulating cell-free nucleic acids will soon be utilized in the clinical management of metastatic castrate-resistant prostate cancer patients.
... Their study showed that it is possible to determine the mRNA of the PD-L1 gene, and quantification of PD-L1 gene expression is feasible. The authors suggest that ctRNA isolated from blood may be a potential alternative to tissue PD-L1 assay [107]. Second, applications of liquid biopsy have also been reported across several tumor types to evaluate the status of the microsatellites [108]. ...
... Gastric cancer-derived exosomal microRNAs and clonal mutations or CNVs detectable in ctDNA may contribute resistance to chemotherapy or HER2 inhibition, respectively [76][77][78]89,90,123]. Although there are limitations to CTC-based PD-L1 verification, there are other ways to determine PD-L1: from exosomal PD-L1 or to detect and quantify PD-L1 mRNA from ctRNA [104,105,107]. Data are conflicting and limited around cfDNA-based EBV detection and epigenomic applications [110,111]. ...
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(1) Background: Liquid biopsy (LB) is a novel diagnostic method with the potential of revolutionizing the prevention, diagnosis, and treatment of several solid tumors. The present paper aims to summarize the current knowledge and explore future possibilities of LB in the management of metastatic gastric cancer. (2) Methods: This narrative review examined the most recent literature on the use of LB-based techniques in metastatic gastric cancer and the current LB-related clinical trial landscape. (3) Results: In gastric cancer, the detection of circulating cancer cells (CTCs) has been recognized to have a prognostic role in all the disease stages. In the setting of localized disease, cell-free DNA (cfDNA) and circulating tumor DNA (ctDNA) qualitative and quantitative detection have the potential to inform on the risk of cancer recurrence and metastatic dissemination. In addition, gastric cancer-released exosomes may play an essential part in metastasis formation. In the metastatic setting, the levels of cfDNA show a positive correlation with tumor burden. There is evidence that circulating tumor microemboli (CTM) in the blood of metastatic patients is an independent prognostic factor for shorter overall survival. Gastric cancer-derived exosomal microRNAs or clonal mutations and copy number variations detectable in ctDNA may contribute resistance to chemotherapy or targeted therapies, respectively. There is conflicting and limited data on CTC-based PD-L1 verification and cfDNA-based Epstein–Barr virus detection to predict or monitor immunotherapy responses. (4) Conclusions: Although preliminary studies analyzing LBs in patients with advanced gastric cancer appear promising, more research is required to obtain better insights into the molecular mechanisms underlying resistance to systemic therapies. Moreover, validation and standardization of LB methods are crucial before introducing them in clinical practice. The feasibility of repeatable, minimally invasive sampling opens up the possibility of selecting or dynamically changing therapies based on prognostic risk or predictive biomarkers, such as resistance markers. Research is warranted to exploit a possible transforming area of cancer care.
... Additionally, since most studies used a low-speed centrifugation and did not use exosome isolation protocols, sPD-L1 detected in these studies should also contain cePD-L1. sPD-L1 may also contain PD-L1 mRNA or DNA released from cells in the tumor microenvironment [292,299,300]. Many studies have shown that high levels of sPD-L1 are generally associated with a poor prognosis in many types of cancers, such as lung cancer, melanoma, and renal cell carcinoma, among others [301][302][303][304]. ...
Article
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While promising, PD-L1 expression on tumor tissues as assessed by immunohistochemistry has been shown to be an imperfect biomarker that only applies to a limited number of cancers, whereas many patients with PD-L1-negative tumors still respond to anti-PD-(L)1 immunotherapy. Recent studies using patient blood samples to assess immunotherapeutic responsiveness suggests a promising approach to the identification of novel and/or improved biomarkers for anti-PD-(L)1 immunotherapy. In this review, we discuss the advances in our evolving understanding of the regulation and function of PD-L1 expression, which is the foundation for developing blood-based PD-L1 as a biomarker for anti-PD-(L)1 immunotherapy. We further discuss current knowledge and clinical study results for biomarker identification using PD-L1 expression on tumor and immune cells, exosomes, and soluble forms of PD-L1 in the peripheral blood. Finally, we discuss key challenges for the successful development of the potential use of blood-based PD-L1 as a biomarker for anti-PD-(L)1 immunotherapy.
... PD-L1 gene amplification might also be evaluated in cfDNA, while PD-L1 expression was detected in cfRNA in the majority of BC patients' blood [50]. ...
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... from the biomarker Ct values to generate DCt. We next followed a reported method [21] to calculate the relative gene expression in various saliva samples: Relative Gene Expression = 2 (-DCt) Â K, where K was chosen as 1000 in our study. ...
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... Raw Ct data was normalized by subtracting GAPDH Ct values from the biomarker Ct values to generate ΔCt. The relative gene expression were calculated by following the 2 -ΔCT method as reported previously [24], where relative gene expression in a urine sample = 2 ^ (-ΔCt) and multiplying by 1000. ...
Article
Liquid biopsy is becoming a promising method for non-invasive cancer detection. In several proof-of-concept studies, long non-coding RNAs (lncRNAs) were found to be potential biomarkers for bladder cancer detection. The objective of this study was to discover a panel of cell-free, urinary lncRNAs as liquid biopsy biomarkers to non-invasively differentiate bladder cancer from chronic urocystitis. To this end, we collected urine samples from both bladder cancer patients and urocystitis patients. These samples were divided into discovery group and validation group. In the discovery group, the expression levels of 16 cell-free urinary lncRNAs were measured by qPCR to discover candidate biomarkers. The diagnostic performance of the candidate lncRNA biomarkers was then evaluated, which led to a panel of lncRNA biomarkers for bladder cancer detection. The performance of this panel of biomarkers was further evaluated in the validation group to see if these lncRNA biomarkers could discriminate the bladder cancer patients from urocystitis patients. We found that all of the 16 lncRNAs evaluated in this study demonstrated significant difference (p<0.05) of expression between bladder cancer patients and urocystitis patients. Nine lncRNAs provided decent diagnostic performance with area under the receiver operating characteristic (ROC) curve (AUC) reaching 0.70 or higher. We then selected the top four lncRNAs, namely UCA1-201, HOTAIR, HYMA1 and MALAT1, to form a panel of urinary biomarkers. Using this panel, bladder cancer patients could be discriminated from urocystitis patients, with sensitivity and specificity reaching 95.7% and 94.3%, respectively. Finally, we confirmed the applicability of the four-lncRNA panel in an independent validation study that included 60 bladder cancer patients and 60 urocystitis patients. Our study paves the way for further studies aimed at large-scale clinical tests of developing lncRNA biomarkers in urine for bladder cancer diagnostics.
... The Ct value was then used to calculate relative mRNA level, as described previously. [19] In sum, DCt value was generated by normalizing the mRNA level to Ct of GAPDH. The level of mRNA was quantified as 2 (À DCt) multiplied by 1000. ...
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Liquid biopsy is an emerging technique for noninvasive detection of various cancers. Majority of liquid biopsy tests still, however, use solitary type of biomarkers with unsatisfactory sensitivity and specificity. To this end, a combined approach of circulating tumor cells (CTCs) and salivary mRNA biomarkers was evaluated for discriminating non-small-cell lung cancer (NSCLC) from healthy controls.Our study included a discovery phase to find multiple biomarkers, and an independent validation phase to confirm the applicability of the selected biomarkers. In the discovery phase, CTC level in blood and 5 mRNA biomarkers in saliva (i.e., CCNI, Epidermal growth factor receptor [EGFR], FGF19, FRS2, and GREB1) were measured for 140 NSCLC patients and 140 healthy controls, followed by developing a predictive model. Next, this panel of biomarkers was applied to another patient cohort consisted of 60 patients with NSCLC and 60 healthy controls in the validation phase.We found that our novel biomarker panel could differentiate patients with NSCLC from healthy controls with high sensitivity (92.1%) and high specificity (92.9%) in the discovery phase. In the validation phase, we achieved sensitivity of 88.3% and specificity of 90.0%.To our best knowledge, it is the first time that a combined use of CTC and salivary mRNA biomarkers were applied for noninvasive detection of NSCLC.
... PD-L1 expression was detected in the plasma ctRNA of all cancer types at varying frequencies but no PD-L1 messenger RNA (mRNA) was detected in cancer-free individuals there was a high degree of concordance between expression of PD-L1 protein in tumor tissues and PD-L1 gene expression in plasma, and both methods were equally predictive of pharmacological response. These findings may provide additional predictive information on the outcome of patients on anti-PD-L1 therapy [61]. In addition, elevated levels of telomerase reverse transcriptase mRNA (hTERT) are often found in different types of tumors such as breast or colon cancer but no hTERT mRNA was detected in cancer-free individuals [59]. ...
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In recent years, there has been an increase in knowledge of cancer, accompanied by a technological development that gives rise to medical oncology. An instrument that allows the implementation of individualized therapeutic strategies is the liquid biopsy. Currently, it is the most innovative methodology in medical oncology. Its high potential as a tool for screening and early detection, the possibility of assessing the patient’s condition after diagnosis and relapse, as well as the effectiveness of real-time treatments in different types of cancer. Liquid biopsy is capable of overcoming the limitations of tissue biopsies. The elements that compose the liquid biopsy are circulating tumor cells, circulating tumor nucleic acids, free of cells or contained in exosomes, microvesicle and platelets. Liquid biopsy studies are performed on various biofluids extracted in a non-invasive way, and they can be performed both from the blood and in urine, saliva or cerebrospinal fluid. The development of genotyping techniques, using the elements that make up liquid biopsy, make it possible to detect mutations, intertumoral and intratumoral heterogeneity, and provide molecular information on cancer for application in medical oncology in an individualized way in different types of tumors. Therefore, liquid biopsy has the potential to change the way medical oncology could predict the course of the disease.
... The cycling parameters for miRNA were as follows: 95 °C for 30 sec, followed by 40 cycles of 95 °C for 5 sec and 60 °C for 30 sec. Finally, we quantified the miRNA level by using the ΔCt method that was previously described [37][38][39] . In short, the miRNA level = 2^ ΔCt multiplying 1000, where ΔCt was the difference between Ct value of the miRNA of interest to Ct value of internal controls. ...
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Recently, we have been seeing emerging applications of non-invasive approaches using serum biomarkers including miRNA and proteins in detection of multiple cancers. Currently, majority of these methods only use solitary type of biomarkers, which often lead to non-satisfactory sensitivity and specificity in clinical applications. To this end, we established a unique biomarker panel in this study, which determined both squamous cell carcinoma antigen (SCC Ag) degree and miRNA-29a, miRNA-25, miRNA-486-5p levels in blood for detection of early-stage cervical cancer. We designed our study with two phases: a biomarker discovery phase, followed by an independent validation phase. In total of 140 early-stage cervical cancer patients (i.e., AJCC stage I and II) and 140 healthy controls recruited in the biomarker discovery phase, we achieved sensitivity of 88.6% and specificity of 92.9%. To further assess the predictive power of our panel, we used it to an independent patient cohort that consisted of 60 early-stage cervical cancer individuals as well as 60 healthy controls, and successfully achieved both high sensitivity (80.0%) and high specificity (96.7%). Our study indicated combining analyses of multiple serum biomarkers could improve the accuracy of non-invasive detection of early-stage cervical cancer, and potentially serve as a new liquid biopsy approach for detecting early-stage cervical cancer.
... Notably, the changes in ctDNA may also serve as an indicator for distinguishing the pseudo from true progression in tumor patients that receiving anti-PD-1 treatment [229]. In addition, assessment of the frequency and quantity of PD-L1 expression in circulating tumor RNA showed a high concordance to that of tumor tissues, and both of them have the same efficacy for predicting the response to nivolumab [230]. Attractively, similar to the TMB, blood TMB (bTMB) has been identified to be a surrogate marker for forecasting the effect of atezolizumab in NSCLC [231]. ...
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Rapidly increasing usages of immune checkpoint therapy for cancer treatment, particularly monoclonal antibodies that target programmed cell death-1 (PD-1) and its ligand PD-L1, have been achieved due to startling durable therapeutic efficacy with limited toxicity. The therapeutics significantly prolonged the overall survival and progression free survival of patients across multiple cancer types. However, the objective response rate of patients receiving this kind of treatment is substantially low. Therefore, it is of great importance to exploit reliable biomarkers that can robustly predict the therapeutic effects. Several biomarkers have been characterized for the selection of patients, which is mainly based on immunological and genetic criteria. Herein, we focus on the current progress regarding the biomarkers for anti-PD-1/PD-L1 therapy.
... The primers used in qPCR analysis were listed in Table 2. Raw Ct data was normalized by subtracting GAPDH Ct values from the biomarker Ct values to generate DCt. We next followed a reported method [18] to calculate the relative gene expression in various saliva samples: Relative Gene Expression ¼ 2 Ù (ÀDCt) Ã K, where K was chosen as 1000 in our study. ...
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... In addition, the efficacy of pembrolizumab was also related to circulating tumor DNA (ctDNA). Compared to patients with a low ctDNA mutation load, patients with a high mutation load had higher ORRs (30). ...
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... It was recently found that the levels of PD-L1, measured from cfRNA in patients with NSCLC prior to immune checkpoint inhibitor treatment, are significantly associated with the response to immunotherapy, and that the changes in PD-L1 RNA over time can signal the onset of progressive disease before CT scan documentation [11]. In other studies, the expression level of PD-L1 in the plasma of cancer patients had a high degree of concordance with the corresponding tissues [12,13]. ...
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... ctDNA has been also used to identify genetic alterations since both somatic and germline mutations can be detected through ctDNA analyses. An important advantage of using ctDNA is the possibility of complementing somatic information from metastatic sites to investigate the mutational heterogeneity of the tumor by gaining a more reliable data compared to the information retrievable from a single tissue biopsy [153,154]. ...
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... As an immune suppression mechanism, the expression of PD-L1 is elevated in many types of cancer and is often correlated with poor prognosis, and is predictive of responses to the antibodies against PD-1/PD-L1 [13,14] . Therapies that block this interaction have demonstrated very promising clinical activity in several cancer types [15,16] . Preliminary data from our group on the measurement of PD-L1 by reverse transcription (RT)-PCR using cfRNA from 760 patients demonstrated PD-L1 expression by cfRNA was similar to levels detected by IHC analysis of tumor tissue [17] . ...
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Evasion of immune system is a hallmark of cancer, which enables cancer cells to escape the attack from immune cells. Cancer cells can express many immune inhibitory signalling proteins to cause immune cell dysfunction and apoptosis. One of these inhibitory molecules is programmed death-ligand 1 (PD-L1), which binds to programmed death 1 (PD-1) expressed on T-cells, B-cells, dendritic cells and natural killer T-cells to suppress anti-cancer immunity. Therefore, anti-PD-L1 and anti-PD-1 antibodies have been used for the treatment of cancer, showing promising outcomes. However, only a proportion of patients respond to the treatments. Further understanding of the regulation of PD-L1 expression could be helpful for the improvement of anti-PD-L1 and PD-1 treatments. Studies have shown that PD-L1 expression is regulated by signalling pathways, transcriptional factors and epigenetic factors. In this review, we summarise the recent progress of the regulation of PD-L1 expression in cancer cells and propose a regulatory model for unified explanation. Both PI3K and MAPK pathways are involved in PD-L1 regulation but the downstream molecules that control PD-L1 and cell proliferation may differ. Transcriptional factors hypoxia-inducible factor-1α and signal transducer and activation of transcription 3 act on the promoter of PD-L1 to regulate its expression. In addition, microRNAs including miR-570, miR-513, miR-197, miR-34a and miR-200 negatively regulate PD-L1. Clinically, it could increase treatment efficacy of targeted therapy by choosing those molecules that control both PD-L1 expression and cell proliferation.
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Colorectal cancers (CRCs) evolve by a reiterative process of genetic diversification and clonal evolution. The molecular profile of CRC is routinely assessed in surgical or bioptic samples1. Genotyping of CRC tissue has inherent limitations; a tissue sample represents a single snapshot in time, and it is subjected to spatial selection bias owing to tumor heterogeneity. Repeated tissue samples are difficult to obtain and cannot be used for dynamic monitoring of disease progression and response to therapy. We exploited circulating tumor DNA (ctDNA) to genotype colorectal tumors and track clonal evolution during treatment with the epidermal growth factor receptor (EGFR)-specific antibodies cetuximab or panitumumab. We identified alterations in ctDNA of patients with primary or acquired resistance to EGFR blockade in the following genes: KRAS, NRAS, MET, ERBB2, FLT3, EGFR and MAP2K1. Mutated KRAS clones, which emerge in blood during EGFR blockade, decline upon withdrawal of EGFR-specific antibodies, indicating that clonal evolution continues beyond clinical progression. Pharmacogenomic analysis of CRC cells that had acquired resistance to cetuximab reveals that upon antibody withdrawal KRAS clones decay, whereas the population regains drug sensitivity. ctDNA profiles of individuals who benefit from multiple challenges with anti-EGFR antibodies exhibit pulsatile levels of mutant KRAS. These results indicate that the CRC genome adapts dynamically to intermittent drug schedules and provide a molecular explanation for the efficacy of rechallenge therapies based on EGFR blockade.
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Early detection of epidermal growth factor receptor (EGFR) mutation, particularly EGFR T790M mutation, is of clinical significance. The aim of the present study was to compare the performances of amplification refractory mutation system-based quantitative polymerase chain reaction (ARMS-qPCR) and droplet digital polymerase chain reaction (ddPCR) approaches in the detection of EGFR mutation and explore the feasibility of using ddPCR in the detection of samples with low mutation rates. EGFR gene mutations in plasmid samples with different T790M mutation rates (0.1-5%) and 10 clinical samples were detected using the ARMS-qPCR and ddPCR approaches. The results demonstrated that the ARMS-qPCR method stably detected the plasmid samples (6,000 copies) with 5 and 1% mutation rates, while the ddPCR approach reliably detected those with 5% (398 copies), 1% (57 copies), 0.5% (24 copies) and 0.1% (average 6 copies) mutation rates. For the 10 clinical samples, the results for nine samples by the ARMS-qPCR and ddPCR methods were consistent; however, the sample N006, indicated to be EGFR wild-type by ARMS-qPCR, was revealed to have a clear EGFR T790M mutation with seven copies of mutant alleles in a background of 6,000 wild-type copies using ddPCR technology. This study demonstrates the feasibility of applying the ddPCR system to detect EGFR mutation and identified the advantage of ddPCR in the detection of samples with a low EGFR mutation abundance, particularly the secondary EGFR T790M resistance mutation, which enables early diagnosis before acquired resistance to tyrosine kinase inhibitors becomes clinically detectable.
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New insight on the interaction between the immune system and tumor has identified the programmed death-1/programmed death-1 ligand pathway to be a key player in evading host immune response. The immune checkpoint modulator, nivolumab (BMS-936558/ONO-4538), is the first PD-1 inhibitor to gain regulatory approval, for the treatment of patients with unresectable melanoma. This review will discuss results from early phase studies of nivolumab in solid tumors including non-small cell lung cancer (NSCLC) as well as studies of nivolumab in combination with chemotherapy, other immune modulators and molecular targeted therapy in patients with NSCLC.
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Expression of programmed cell death receptor ligand 1 (PDL1) has been scarcely studied in breast cancer. Recently PD1/PDL1-inhibitors have shown promising results in different carcinomas with correlation between PDL1 tumor expression and responses. We retrospectively analyzed PDL1 mRNA expression in 45 breast cancer cell lines and 5,454 breast cancers profiled using DNA microarrays. Compared to normal breast samples, PDL1 expression was upregulated in 20% of clinical samples and 38% of basal tumors. High expression was associated with poor-prognosis features (large tumor size, high grade, ER-negative, PR-negative, ERBB2-positive status, high proliferation, basal and ERBB2-enriched subtypes). PDL1 upregulation was associated with biological signs of strong cytotoxic local immune response. PDL1 upregulation was not associated with survival in the whole population, but was associated with better metastasis-free and overall specific survivals in basal tumors, independently of clinicopathological features. Pathological complete response after neoadjuvant chemotherapy was higher in case of PDL1 upregulation (50% versus 21%). In conclusion, PDL1 upregulation, more frequent in basal breast cancers, was associated with increased T-cell cytotoxic immune response. In this aggressive subtype, upregulation was associated with better survival and response to chemotherapy. Reactivation of dormant tumor-infiltrating lymphocytes by PDL1-inhibitors could represent promising strategy in PDL1-upregulated basal breast cancer.
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Introduction: In the phase IV, open-label, single-arm study NCT01203917, first-line gefitinib 250 mg/d was effective and well tolerated in Caucasian patients with epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (previously published). Here, we report EGFR mutation analyses of plasma-derived, circulating-free tumor DNA. Methods: Mandatory tumor and duplicate plasma (1 and 2) baseline samples were collected (all screened patients; n = 1060). Preplanned, exploratory analyses included EGFR mutation (and subtype) status of tumor versus plasma and between plasma samples. Post hoc, exploratory analyses included efficacy by tumor and plasma EGFR mutation (and subtype) status. Results: Available baseline tumor samples were 1033 of 1060 (118 positive of 859 mutation status known; mutation frequency, 13.7%). Available plasma 1 samples were 803 of 1060 (82 positive of 784 mutation status known; mutation frequency, 10.5%). Mutation status concordance between 652 matched tumor and plasma 1 samples was 94.3% (95% confidence interval [CI], 92.3-96.0) (comparable for mutation subtypes); test sensitivity was 65.7% (95% CI, 55.8-74.7); and test specificity was 99.8% (95% CI, 99.0-100.0). Twelve patients of unknown tumor mutation status were subsequently identified as plasma mutation-positive. Available plasma 2 samples were 803 of 1060 (65 positive of 224 mutation status-evaluable and -known). Mutation status concordance between 224 matched duplicate plasma 1 and 2 samples was 96.9% (95% CI, 93.7-98.7). Objective response rates are as follows: mutation-positive tumor, 70% (95% CI, 60.5-77.7); mutation-positive tumor and plasma 1, 76.9% (95% CI, 65.4-85.5); and mutation-positive tumor and mutation-negative plasma 1, 59.5% (95% CI, 43.5-73.7). Median progression-free survival (months) was 9.7 (95% CI, 8.5-11.0; 61 events) for mutation-positive tumor and 10.2 (95% CI, 8.5-12.5; 36 events) for mutation-positive tumor and plasma 1. Conclusion: The high concordance, specificity, and sensitivity demonstrate that EGFR mutation status can be accurately assessed using circulating-free tumor DNA. Although encouraging and suggesting that plasma is a suitable substitute for mutation analysis, tumor tissue should remain the preferred sample type when available.
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High-throughput DNA sequencing is revolutionizing the study of cancer and enabling the measurement of the somatic mutations that drive cancer development. However, the resulting sequencing datasets are large and complex, obscuring the clinically important mutations in a background of errors, noise, and random mutations. Here, we review computational approaches to identify somatic mutations in cancer genome sequences and to distinguish the driver mutations that are responsible for cancer from random, passenger mutations. First, we describe approaches to detect somatic mutations from high-throughput DNA sequencing data, particularly for tumor samples that comprise heterogeneous populations of cells. Next, we review computational approaches that aim to predict driver mutations according to their frequency of occurrence in a cohort of samples, or according to their predicted functional impact on protein sequence or structure. Finally, we review techniques to identify recurrent combinations of somatic mutations, including approaches that examine mutations in known pathways or protein-interaction networks, as well as de novo approaches that identify combinations of mutations according to statistical patterns of mutual exclusivity. These techniques, coupled with advances in high-throughput DNA sequencing, are enabling precision medicine approaches to the diagnosis and treatment of cancer.
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Recent strategies targeting the interaction of the programmed cell death ligand-1 (PD-L1, B7-H1, CD274) with its receptor, PD-1, resulted in promising activity in early phase clinical trials. In this study, we used various antibodies and in situ mRNA hybridization to measure PD-L1 in non-small cell lung cancer (NSCLC) using a quantitative fluorescence (QIF) approach to determine the frequency of expression and prognostic value in two independent populations. A control tissue microarray (TMA) was constructed using PD-L1-transfected cells, normal human placenta and known PD-L1-positive NSCLC cases. Only one of four antibodies against PD-L1 (5H1) validated for specificity on this TMA. In situ PD-L1 mRNA using the RNAscope method was similarly validated. Two cohorts of NSCLC cases in TMAs including 340 cases from hospitals in Greece and 204 cases from Yale University were assessed. Tumors showed PD-L1 protein expression in 36% (Greek) and 25% (Yale) of the cases. PD-L1 expression was significantly associated with tumor-infiltrating lymphocytes in both cohorts. Patients with PD-L1 (both protein and mRNA) expression above the detection threshold showed statistically significant better outcome in both series (log-rank P=0.036 and P=0.027). Multivariate analysis showed that PD-L1 expression was significantly associated with better outcome independent of histology. Measurement of PD-L1 requires specific conditions and some commercial antibodies show lack of specificity. Expression of PD-L1 protein or mRNA is associated with better outcome. Further studies are required to determine the value of this marker in prognosis and prediction of response to treatments targeting this pathway.Laboratory Investigation advance online publication, 11 November 2013; doi:10.1038/labinvest.2013.130.
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This pilot study assessed correlations between circulating tumor cells (CTCs) and circulating free DNA (cfDNA) of metastatic non-small cell lung cancer (NSCLC) after acquisition of resistance to epidermal growth factor receptor tyrosine kinase inhibitors. CTCs were counted using the CellSearch system (Veridex). cfDNA was analyzed for EGFR mutation status by the Cycleave real-time PCR assay. Twenty-four patients participated in this study. CTCs were detected in 8 of 24 cases (33.3%), at a mean of 2.6 CTCs per 7.5 ml blood (range: 1-24). EGFR mutations in cfDNA were detected in 6 out of 24 cases (25%). The EGFR mutation detection rates in cfDNA were significantly higher in patients with ≥ 2 CTCs per 7.5 ml (100%) than in those with <2 CTCs per 7.5 ml (10%) (p=0.0001). The presence of CTCs was correlated with the positivity of EGFR mutation in cfDNA.
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MicroRNAs (miRNAs) are small, noncoding RNAs that play an important role in regulating various biological processes through their interaction with cellular messenger RNAs. Extracellular miRNAs in serum, plasma, saliva, and urine have recently been shown to be associated with various pathological conditions including cancer. With the goal of assessing the distribution of miRNAs and demonstrating the potential use of miRNAs as biomarkers, we examined the presence of miRNAs in 12 human body fluids and urine samples from women in different stages of pregnancy or patients with different urothelial cancers. Using quantitative PCR, we conducted a global survey of the miRNA distribution in these fluids. miRNAs were present in all fluids tested and showed distinct compositions in different fluid types. Several of the highly abundant miRNAs in these fluids were common among multiple fluid types, and some of the miRNAs were enriched in specific fluids. We also observed distinct miRNA patterns in the urine samples obtained from individuals with different physiopathological conditions. MicroRNAs are ubiquitous in all the body fluid types tested. Fluid type-specific miRNAs may have functional roles associated with the surrounding tissues. In addition, the changes in miRNA spectra observed in the urine samples from patients with different urothelial conditions demonstrates the potential for using concentrations of specific miRNAs in body fluids as biomarkers for detecting and monitoring various physiopathological conditions.
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The ligands for programmed cell death 1 (PD-1), an immunoinhibitory receptor belonging to CD28/cytotoxic T lymphocyte antigen 4 family, are PD-1 ligand 1 and 2 (PD-Ls). Recent reports suggest that the aberrant expression of PD-Ls on tumor cells impairs antitumor immunity, resulting in the immune evasion of the tumor cells. Although an inverse correlation between the expression level of PD-Ls and patients' prognosis has been reported for several malignant tumors, the follow-up period was limited because of the lack of the antibody (Ab) applicable to paraffin-embedded specimens. Here we generated a new Ab against PD-1 ligand 1 (PD-L1) and analyzed the expression level of PD-Ls in human ovarian cancer using paraffin-embedded specimens. Patients with higher expression of PD-L1 had a significantly poorer prognosis than patients with lower expression. Although patients with higher expression of PD-1 ligand 2 also had a poorer prognosis, the difference was not statistically significant. A significant inverse correlation was observed between PD-L1 expression and the intraepithelial CD8(+) T lymphocyte count, suggesting that PD-L1 on tumor cells directly suppresses antitumor CD8(+) T cells. Multivariate analysis showed the expression of PD-L1 on tumor cells and intraepithelial CD8(+) T lymphocyte count are independent prognostic factors. The PD-1/PD-L pathway can be a good target for restoring antitumor immunity in ovarian cancer.
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Background/aim: The cell surface receptor programmed death-1 (PD1) and its ligand (PDL1) have been detected in various cancer types. It has been reported that expression of PDL1 and PD1 in a tumor is associated with poor prognosis of the patient. In the present study, we retrospectively examined tumor expression of PDL1 and intratumoral PD1(+) cell infiltration, and assessed their relationship with patient prognosis according to the pathological stage of gastric cancer. Materials and methods: PDL1 and PD1 expression in primary tumors from 431 patients was evaluated using immunohistochemistry. The association between the expression of PDL1/PD1 and clinicopathological features was assessed. Results: High expression of PDL1 was observed in 128 (29.6%) patients. PDL1 expression was correlated with tumor infiltration of PD1(+) cells. In multivariate analysis, PDL1 expression was associated with worse overall survival. In subset analysis, PDL1 expression was significantly associated with survival in patients with stage II/III gastric cancer. In conclusion, PDL1 was an independent prognostic factor for patients with stage II/III gastric cancer. Our results suggested that patients with stage II/III gastric cancer might be appropriate for PD1/PDL1-targeted therapy.
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Background: Circulating cell-free DNA (cfDNA) in plasma is a mixture of DNA from malignant and normal cells, and can be used as a liquid biopsy to detect and quantify tumour specific mutations e.g. KRAS. We investigated the clinical value of KRAS mutations when detected in plasma compared to tumour in patients from metastatic colorectal cancer (mCRC) prior to anti-epidermal growth factor receptor (anti-EGFR) therapy. Secondly, we investigated the concentration of total cfDNA in relation to clinical outcome. Patients and methods: Patients were resistant to 5-FU, oxaliplatin and irinotecan and treated with 3rd line irinotecan (180mg/m(2)) and cetuximab (500mg/m(2)) q2w in a prospective phase II trial. The study was conducted prior to implementation of KRAS as selection criteria. Plasma was obtained from a pre-treatment EDTA blood-sample, and the total cfDNA, and KRAS mutations were quantified by an in-house qPCR method. Results are presented according to REMARK. Results: One-hundred-and-forty patients were included. Thirty-four percent had detectable KRAS mutations in the tumour, compared to 23% in plasma. KRAS detection in archival tumour tissue showed no correlation to survival, whereas plasma KRAS status remained a strong predictive and prognostic factor in multivariate analysis (Hazard Ratio (HR)=2.98 (95% CI 1.53-5.80, p=0.001) and 2.84 (1.46-5.53, p=0.002), for OS and PFS, respectively). Combining the information of total cell free DNA levels and plasma KRAS mutation status, produced an additional prognostic effect. Conclusion: The value of clinically relevant mutations could be improved by performing the analysis on circulation plasma DNA rather than archival tumour tissue.
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Background: We assessed the efficacy and safety of programmed cell death 1 (PD-1) inhibition with pembrolizumab in patients with advanced non-small-cell lung cancer enrolled in a phase 1 study. We also sought to define and validate an expression level of the PD-1 ligand 1 (PD-L1) that is associated with the likelihood of clinical benefit. Methods: We assigned 495 patients receiving pembrolizumab (at a dose of either 2 mg or 10 mg per kilogram of body weight every 3 weeks or 10 mg per kilogram every 2 weeks) to either a training group (182 patients) or a validation group (313 patients). We assessed PD-L1 expression in tumor samples using immunohistochemical analysis, with results reported as the percentage of neoplastic cells with staining for membranous PD-L1 (proportion score). Response was assessed every 9 weeks by central review. Results: Common side effects that were attributed to pembrolizumab were fatigue, pruritus, and decreased appetite, with no clear difference according to dose or schedule. Among all the patients, the objective response rate was 19.4%, and the median duration of response was 12.5 months. The median duration of progression-free survival was 3.7 months, and the median duration of overall survival was 12.0 months. PD-L1 expression in at least 50% of tumor cells was selected as the cutoff from the training group. Among patients with a proportion score of at least 50% in the validation group, the response rate was 45.2%. Among all the patients with a proportion score of at least 50%, median progression-free survival was 6.3 months; median overall survival was not reached. Conclusions: Pembrolizumab had an acceptable side-effect profile and showed antitumor activity in patients with advanced non-small-cell lung cancer. PD-L1 expression in at least 50% of tumor cells correlated with improved efficacy of pembrolizumab. (Funded by Merck; KEYNOTE-001 ClinicalTrials.gov number, NCT01295827.).
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The immune checkpoint proteins programmed death-1/ligand (PD-1/PD-L1) play a critical role in immune escape of tumor cells. In models of epidermal growth factor receptor (EGFR)-driven non-small-cell lung cancer (NSCLC), EGFR signal upregulates PD-1/PD-L1. However, data on the clinical significance of PD1/PD-L1 expression in patients with the subtype of NSCLC carrying EGFR mutations remain limited. Immunohistochemistry was performed to evaluate the expression of PD-1, PD-L1, and CD4+ and CD8+ tumor-infiltrating T lymphocytes (TILs). In a cohort of 56 patients, PD-L1 and PD-1 was positive in 53.6% and 32.1% of tumor specimens, respectively. PD-L1(+) patients had a significantly greater disease-control rate (P = .004), in association with longer progression-free survival (P = .001) after EGFR-tyrosine kinase inhibitor (TKI) therapy and overall survival (P = .004), and no correlation between PD-1 positivity and clinical outcomes was observed. PD-L1 expression was not significantly associated with either clinicopathologic features or TILs. These findings suggest that this subtype of EGFR mutation-positive NSCLC is highly eligible for PD-1/PD-L1 immunotherapy. PD-L1 might represent a favorable biomarker candidate for the response to EGFR-TKIs and outcomes of these patients with NSCLC. Copyright © 2015 Elsevier Inc. All rights reserved.
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"Tonight, I'm launching a new Precision Medicine Initiative to bring us closer to curing diseases like cancer and diabetes - and to give all of us access to the personalized information we need to keep ourselves and our families healthier." - President Barack Obama, State of the Union Address, January 20, 2015 President Obama has long expressed a strong conviction that science offers great potential for improving health. Now, the President has announced a research initiative that aims to accelerate progress toward a new era of precision medicine (www.whitehouse.gov/precisionmedicine). We believe that the time is right for this visionary initiative, . . .
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The development of human cancer is a multistep process characterized by the accumulation of genetic and epigenetic alterations that drive or reflect tumour progression. These changes distinguish cancer cells from their normal counterparts, allowing tumours to be recognized as foreign by the immune system. However, tumours are rarely rejected spontaneously, reflecting their ability to maintain an immunosuppressive microenvironment. Programmed death-ligand 1 (PD-L1; also called B7-H1 or CD274), which is expressed on many cancer and immune cells, plays an important part in blocking the 'cancer immunity cycle' by binding programmed death-1 (PD-1) and B7.1 (CD80), both of which are negative regulators of T-lymphocyte activation. Binding of PD-L1 to its receptors suppresses T-cell migration, proliferation and secretion of cytotoxic mediators, and restricts tumour cell killing. The PD-L1-PD-1 axis protects the host from overactive T-effector cells not only in cancer but also during microbial infections. Blocking PD-L1 should therefore enhance anticancer immunity, but little is known about predictive factors of efficacy. This study was designed to evaluate the safety, activity and biomarkers of PD-L1 inhibition using the engineered humanized antibody MPDL3280A. Here we show that across multiple cancer types, responses (as evaluated by Response Evaluation Criteria in Solid Tumours, version 1.1) were observed in patients with tumours expressing high levels of PD-L1, especially when PD-L1 was expressed by tumour-infiltrating immune cells. Furthermore, responses were associated with T-helper type 1 (TH1) gene expression, CTLA4 expression and the absence of fractalkine (CX3CL1) in baseline tumour specimens. Together, these data suggest that MPDL3280A is most effective in patients in which pre-existing immunity is suppressed by PD-L1, and is re-invigorated on antibody treatment.
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Next-generation sequencing studies have provided further evidence to support the notion that cancer is a disease characterized by Darwinian evolution. Today, we often fail to capture this evolution and treatment decisions, even in the metastatic setting, are often based on analysis of primary tumor diagnosed years ago. Currently, this is considered a major reason for treatment failures in cancer care. Recent technological advances in the detection and characterization of circulating tumor cells and circulating tumor DNA might address this and allow for treatment tailoring based on real-time monitoring of tumor evolution. In this review, we summarize the most important recent findings in the field, focusing on challenges and opportunities in moving these tools forward in clinical practice.
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A radioimmunoassay for ng quantities of DNA was developed. [125l]lododeoxyuridine-labeled DNA was used as the antigen, and the serum of a lupus erythematosus patient served as the source of antibody. The level of free DNA in the serum of 173 patients with various types of cancer and in 55 healthy individuals was determined by this radioimmunoassay. DNA concentration in the normal controls had a range of 0 to 100 ng/ml with a mean of 13 +/- 3 ng/ml (S.E.). For comparison purposes, the range of 0 to 50 ng/ml was designated as normal, and 93% of controls were found in this range. In the cancer patients, the DNA concentration ranged from zero to mug levels with a mean of 180 +/- 38 ng/ml. Fifty % of the patients values were found in the range of 0 to 50 ng/ml; the other 50% were between 50 and 5000 ng/ml. No correlation could be seen between DNA levels and the size or location of the primary tumor. Significantly higher DNA levels, however, were found in the serum of patients with metastatic disease (mean of 209 +/- 39 ng/ml), as compared to nonmetastatic patients (mean 100 +/- 30, p less than 0.02). After radiation therapy in lymphoma, lung, ovary, uterus, and cervical tumors, the levels decreased in 66 to 90% of the patients, whereas in glioma, breast, colon, and rectal tumors, the DNA levels decreased only in 16 to 33% of the patients. Generally, the decrease in DNA concene of tumor size and reduction of pain. Conversely, when DNA levels either increased or remained unchanged, a lack of response to the treatment was noted. Of 17 patients who died within a year, 13 showed DNA levels that remained high or unchanged, whereas only 4 showed lower levels during treatment. Persistent high or increasing DNA levels in the circulation, therefore, may signal a relapse and are probably a poor prognostic sign. The relatively high percentage (50%) of cancer patients with apparently normal DNA levels would suggest that this test may have low diagnostic value. It should be pointed out, however, that all these patients represent a selected group considered for radiation therapy, usually after surgery and/or chemotherapy. It is possible that a better correlation between DNA levels and cancer will be obtained prior to the initiation of treatment. On the other hand, DNA in the serum may be an important tool for the evaluation of therapy or the comparison of different regimens.
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We developed a scoring system that can combine several immunological parameters and express the immune status of individuals as a simple numeral. T cell immune score was obtained by using 5T cell-related parameters: number of T cells, ratio of CD4(+)T cells to CD8(+)T cells, number of naïve T cells, ratio of naïve T cells to memory T cells, and T cell proliferative index (TCPI). TCPI was calculated by using number of T cells and their proliferative activity. We assessed T cell immune score in 103 patients with colorectal cancer and 51 healthy age-matched controls. The results were as follows: (1) T cell-immune score of patients in stages I-IV before surgery was significantly decreased as compared with controls. (2) The number of regulatory T cells in patients in stages I-IV gradually increased with disease progression. (3) T cell immune score was strongly suppressed after surgery, but were recovered to the initial level within a month. (4) Furthermore, restoration of immunological function was attempted in cancer patients by infusion of activated autologous T cells. The effectiveness was confirmed by an increase of TCPI in many cancer patients.
Spanish Lung Cancer Group, Association of EGFR L858R mutation in circulating free DNA
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The immune checkpoint regulator PD-l1 is highly expressed in aggressive primary prostate cancer
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