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The frequency of epidermal growth factor receptor mutations in non-small-cell lung cancer patients from Egypt
Abstract
Background: Lung cancer with mutations in the epidermal growth factor receptor (EGFR) is one of the leading causes of cancer-related death, and non-small-cell lung cancer (NSCLC) has captured the attention of researchers. These mutations occur within EGFR exons 19, 18, 20, and 21. Objective: Our study aimed at determining the prevalence of the mutation in the biopsy samples of NSCLC patients in Egypt. Patients and methods: In this study, 195 adenocarcinoma (ACA) patients with NSCLC were diagnosed and graded on the basis of histopathology using hematoxylin and eosin stain. The samples were subjected to immunohistochemistry studies and were confirmed as positive using TTF1 and as negative using P63. The positive samples were subjected to PCR amplification for EGFR mutation study. Results: On the basis of hematoxylin and eosin-stained sections, 15 of 195 ACA patients were of grade I, 160 patients (the majority) were of grade II, and 20 patients were of grade III (195 vs. 20, P<0.001; 60 vs. 15, P<0.001; 15 vs. 20, P<0.37, statistically nonsignificant). Of the 195 ACA patients, 68 (34.8%) had tumor-associated EGFR mutations, 40 (58.8%) patients had deletion in codon 19, 16 (23.6%) patients had deletion of L858R in codon 21, six (8.8%) patients had insertion in codon 20, three (4.4%) patients had insertion in codon 18, and three (4.4%) patients had multiple mutations [40 vs.16, P<0.001; 40 vs. 6, P<0.001 (highly significant); 40 vs. 3, P<0.001]. As regards sex, the incidence of EGFR mutations was higher in women (41, 60.3%) than in men (27, 39.7%) (68 vs. 41, P<0.05; 68 vs. 27, P<0.05; 41 vs. 27, P<0.05). Tumors with an activating EGFR mutations were more likely to be from nonsmokers (43/63.3%) than from smokers (25/36.7%) (43 vs. 25, P<0.001, significant). Conclusion: The current study has revealed that 34.8% of patients with NSCLC have tumor-associated EGFR mutations. Of which, 58.8% of the mutations were exon 19 deletions. EGFR mutations were more often found in tumors from female nonsmokers with ACA histopathology.
... Also in the Middle East and Africa, EFGR mutations are present in females more than in males [49,81,82]. In studies that included Egyptian participants, it was found that the EGFR mutation incidence is greater in females than in males [48,51,76,77,83,84]. According to the findings of another study, the prevalence of EGFR mutations in females is significantly higher than it is in males (71.4% vs. 28.6%, ...
... Smoking was found to be correlated with a lower incidence of mutation rate in EGFR gene in patients with NSCLC in studies involving many ethnic groups [49,71,81,85], and that poor prognosis in smoking patients diagnosed with NSCLC is related to lower rates of mutations in EGFR gene [60,86]. In Egypt, two different studies reported an incidence rate of EGFR mutations among smokers and nonsmokers that was comparable to the findings of the current study [83,85]. ...
... In a meta-analysis including 26 studies and 3688 NSCLC patients, Ren et al. revealed that nonsmokers had a considerably increased rate of EGFR mutations [108]. Several studies show that nonsmokers, notably females, are more likely than smokers to have tumors with activating EGFR mutations [56,83,85,109]. The mechanism underlying the correlation between nonsmoking status and EGFR mutations is incompletely understood. It has been hypothesized, however, that exposure to tobacco smoke may result in the accumulation of other genetic alterations that can obscure the effect of EGFR mutations [34,110]. ...
Background
Lung cancer is a form of cancer that is responsible for the largest incidence of deaths attributed to cancer worldwide. Non-small cell lung cancer (NSCLC) is the most prevalent of all the subtypes of the disease. Treatment with tyrosine kinase inhibitors (TKI) may help some people who have been diagnosed with non-small cell lung cancer. The presence of actionable mutations in the epidermal growth factor receptor (EGFR) gene is a key predictor of how a patient will respond to a TKI. Thus, the frequency of identification of mutations in EGFR gene in patients with NSCLC can facilitate personalized treatment.
Objective
The objective of this study was to screen for mutations in the EGFR gene and to investigate whether there is a correlation between the screened mutations and various clinical and pathological factors, such as gender, smoking history, and age, in tissue samples from patients with NSCLC.
Methods
The study comprised 333 NSCLC tissue samples from 230 males and 103 females with an average age of 50 years. Exons 18–21 of the EGFR gene have been examined using real-time PCR. Using SPSS, correlations between clinical and demographic variables were examined, and EGFR mutation and clinical features associations were studied.
Results
The study’s findings revealed that the incidence rate of EGFR mutation was 24.32% (81/333), with partial deletion of exon 19 (19-Del) and a point mutation of L858R in exon 21 accounting for 66.67% ( P < 0.001) and 28.40% ( P < 0.001) of the mutant cases, respectively. Patients who had the T790M mutation represent 4.94% ( P = 0.004) of total number of patients. Females harbored EGFR mutations (54.32%) with higher frequency than men (45.68%) ( P < 0.001), while nonsmokers had EGFR mutations (70.37%) more frequently than current smokers (29.63%) ( P < 0.001).
Conclusion
The screening study conducted in Egypt reported that the EGFR mutations prevalence was 24.32% among Egyptians with NSCLC. The study also found a slight gender bias, with females having an incidence rate of these mutations higher than males. Additionally, nonsmokers had higher rates of mutations in EGFR gene compared to smokers. According to the findings, somatic EGFR mutations can be employed as a diagnostic tool for non-small cell lung cancer in Egypt, and they can be implemented in conjunction with clinical criteria to identify which patients are more likely to respond favorably to TKIs.
... In Egypt, one study in Alexandria (coastal city) byZaki & colleagues (2015) showed that exon-19 mutations were detected in 22% and 18% using two methods. However, they tested only for exon-19 and exon-21 mutations in a sample of 50 cases[30].Eid., et al. (2020) reported that the rate of EGFR mutation in Upper Egypt in 34 NSCLC cases was (44.1%) [18]. In a separate study from Cairo, Egypt, 68 (34.8%) of 195 adenocarcinoma patients had tumor-associated EGFR mutations. ...
The association of EGFR mutation status to the relevant clinical and pathological features of the patients was studied using the logistic regression. Results: EGFR mutations were detected in 33 (23.4%) patients. The most detected were 19 Del (18 patients; 12.77%), exon 21 (13 patients; 9.22%), exon 21+T790M, and G719X (one patient; 0.71%); each. EGFR mutation status was associated significantly to advanced disease stage (p < 0.001), brain metastasis 8/19 (42.11%, p = 0.049) and contralateral lung metastasis 7/14 (50%, p = 0.038). EGFR mutations were also higher in females (non-smokers (35%) and in males smokers (20.9%, p < 0.001). Multivariate analysis showed that only the contralateral lung metastasis is an independent predictor for EGFR mutations in the NSCLC patients. Conclusion: EGFR mutations are relatively common (23.4%) in NSCLC patients from Egypt (NCI experience). Therefore, testing for EGFR mutations in NSCLC should be done routinely for those patients for better treatment outcomes.
EGFR mutation is a predictor of epidermal growth factor receptor-tyrosine kinase inhibitor treatment response in patients with non-small-cell lung cancer (NSCLC). However, it remains unclear whether chemotherapy affects EGFR mutation status in NSCLC. We investigated the influence of chemotherapy on EGFR mutations in plasma and tumor tissues from patients with NSCLC.
Samples were derived from three cohorts: one, 264 patients with advanced NSCLC who received first-line chemotherapy with matched pre- and postchemotherapy blood samples; two, 63 patients with stages IIb to IIIb disease with pre- and post-neoadjuvant chemotherapy tumor tissues; and three, 79 patients with advanced NSCLC who underwent palliative surgery. EGFR mutation status was determined and analyzed to reveal potential impact of chemotherapy.
In the first cohort, EGFR mutations were detected in 34.5% of the prechemotherapy plasma samples (91 of 264) but in only 23.1% of the postchemotherapy plasma samples (61 of 264). The decrease in EGFR mutation rate was statistically significant (P < .001). Patients whose EGFR mutations switched from positive to negative after chemotherapy had a better partial response (PR) than patients with a reverse change (P = .037). A similar decrease in EGFR mutation rate was observed in tissues after neoadjuvant chemotherapy in the second cohort (34.9% [22 of 63] v 19.0% [12 of 63]; P = .013). In the third cohort, 38.0% of the tumors (30 of 79) showed an intratumor heterogeneity of EGFR mutation, whereas 62.0% (49 of 79) were homogeneous, either with EGFR mutation or no mutation.
Our results suggest that chemotherapy may reduce EGFR mutation frequency in patients with NSCLC, likely the result of a preferential response of subclones with EGFR mutations in tumors with heterogeneous tumor cell populations.
We aim to develop a simple and sensitive array-based method for the detection of epidermal growth factor receptor (EGFR) gene mutations in the plasma of non-small-cell lung cancer patients and determine its use in the follow-up of those on tyrosine-kinase inhibitor (TKI) therapy.
DNA from 100 μl of plasma was amplified in the presence of peptide nucleic acid clamp to provide single-stranded template for the allele-specific arrayed primer extension reaction, incorporating cyanine-5-deoxycytidine triphosphate in the newly synthesized strands. The fluorescent product was visualized by laser at 670 nm.
Eleven different types of EGFR TKI drug-sensitive mutants (SM) were identified in plasma-DNA from 46 of 51 patients. Five patients carried only wild-type sequence. Plasma-DNA finding was concordant in 36 of 37 cases with tumor-sequencing data. This method could detect as little as 62.5 copies of mutant L858R; 125 copies of E709K + G719A or 625 copies of del 746-750 in the presence of 100,000 copies of wild-type EGFR. In 21 patients on longitudinal follow-up for up to 18 months, SM was found in all initial plasma samples, except for three samples collected after recent chemotherapy. Nine of 16 patients (56%) who responded to TKI had undetectable plasma EGFR mutant. SM was present concurrently with drug-resistant mutant in 44% of patients with disease progression while on TKI, the remaining 56% might have other mechanisms of resistance.
The EGFR array provides a sensitive, inexpensive, and robust method for monitoring non-small-cell lung cancer patients' response to TKI, and obviates the need of repeated lung biopsy.
In IPASS (IRESSA Pan-Asia Study), clinically selected patients with pulmonary adenocarcinoma received first-line gefitinib or carboplatin/paclitaxel. This preplanned, exploratory analysis was conducted to increase understanding of the use of surrogate samples, such as serum, versus tumor biopsy samples for determining EGFR mutation status in the Japanese cohort (n = 233).
EGFR mutations were assessed using tumor tissue-derived DNA (n = 91) and circulating free (cf) DNA from pretreatment serum samples (n = 194).
Fewer patients were EGFR mutation positive when assessed using pretreatment cfDNA (23.7%) versus tumor tissue-derived DNA (61.5%). cfDNA results identified no false positives but a high rate of false negatives (56.9%). There was a significant interaction between cfDNA EGFR mutation status and treatment for progression-free survival (PFS) (p = 0.045). PFS was significantly longer and objective response rate (ORR) higher with gefitinib than carboplatin/paclitaxel in the cfDNA EGFR mutation-positive subgroup (PFS: hazard ratio [HR], 0.29; 95% confidence interval [CI], 0.14-0.60; p < 0.001; ORR: odds ratio [OR], 1.71; 95% CI, 0.48-6.09; 75.0% versus 63.6%; p = 0.40). There was a slight numerical advantage in PFS and ORR for gefitinib over carboplatin/paclitaxel in the cfDNA EGFR mutation-negative subgroup, likely due to the high rate of false negatives within this subgroup.
These results merit further investigation to determine whether alternative sources of tumor DNA, such as cfDNA in serum, could be used for determining EGFR mutation status in future; currently, where a sample is available, analysis of tumor material is recommended.
Purpose
In the phase III INTEREST trial, 1,466 pretreated patients with advanced non–small cell lung cancer (NSCLC) were randomly assigned to receive gefitinib or docetaxel. As a preplanned analysis, we prospectively analyzed available tumor biopsies to investigate the relationship between biomarkers and clinical outcomes.
Methods
Biomarkers included epidermal growth factor receptor (EGFR) copy number by fluorescent in situ hybridization (374 assessable samples), EGFR protein expression by immunohistochemistry (n = 380), and EGFR (n = 297) and KRAS (n = 275) mutations.
Results
For all biomarker subgroups analyzed, survival was similar for gefitinib and docetaxel, with no statistically significant differences between treatments and no significant treatment by biomarker status interaction tests. EGFR mutation–positive patients had longer progression-free survival (PFS; hazard ratio [HR], 0.16; 95% CI, 0.05 to 0.49; P = .001) and higher objective response rate (ORR; 42.1% v 21.1%; P = .04), and patients with high EGFR copy number had higher ORR (13.0% v 7.4%; P = .04) with gefitinib versus docetaxel.
Conclusion
These biomarkers do not appear to be predictive factors for differential survival between gefitinib and docetaxel in this setting of previously treated patients; however, subsequent treatments may have influenced the survival results. For secondary end points of PFS and ORR, some advantages for gefitinib over docetaxel were seen in EGFR mutation–positive and high EGFR copy number patients. There was no statistically significant difference between gefitinib and docetaxel in biomarker-negative patients. This suggests gefitinib can provide similar overall survival to docetaxel in patients across a broad range of clinical subgroups and that EGFR biomarkers such as mutation status may additionally identify which patients are likely to gain greatest PFS and ORR benefit from gefitinib.
KRAS mutation is closely associated to carcinogenesis and prognosis of non-small cell lung cancer (NSCLC). Detection of KRAS mutation can also be used to select NSCLC patients for drug targeting with EGFR tyrosine kinase inhibitors. Data regarding the status of KRAS mutation in mainland China, which would assist in these interventions, is lacking. We have detected KRAS mutation from 103 NSCLC patients in mainland China with high resolution melting analysis (HRM) on LightScanner, and compared this method of detection with sequencing, and found HRM to have greater sensitivity. We found 6 patients (5.8%) with KRAS mutation (3 patients, G12C; 1 patient, G12S; 1 patient, G12V; 1 patient, G13D). KRAS mutation was significantly associated to gender (p=0.027) and pathology types (p=0.000), but not to smoking. The mutation frequency of KRAS in NSCLC patients in mainland China is similar to those in East Asian countries, but lower than those in western countries. However, the spectrum of KRAS mutation in mainland China is similar to those found in the USA. The results also exhibit dependence of KRAS mutation in China on ethnicity. The clinical significance of the spectral pattern of KRAS mutations in TKI resistance or tumorigenesis among patients with NSCLC in mainland China requires further investigation.
Activating mutations in the epidermal growth factor receptor gene (EGFR) confer hypersensitivity to the tyrosine kinase inhibitors gefitinib and erlotinib in patients with advanced non-small-cell lung cancer. We evaluated the feasibility of large-scale screening for EGFR mutations in such patients and analyzed the association between the mutations and the outcome of erlotinib treatment.
From April 2005 through November 2008, lung cancers from 2105 patients in 129 institutions in Spain were screened for EGFR mutations. The analysis was performed in a central laboratory. Patients with tumors carrying EGFR mutations were eligible for erlotinib treatment.
EGFR mutations were found in 350 of 2105 patients (16.6%). Mutations were more frequent in women (69.7%), in patients who had never smoked (66.6%), and in those with adenocarcinomas (80.9%) (P<0.001 for all comparisons). The mutations were deletions in exon 19 (62.2%) and L858R (37.8%). Median progression-free survival and overall survival for 217 patients who received erlotinib were 14 months and 27 months, respectively. The adjusted hazard ratios for the duration of progression-free survival were 2.94 for men (P<0.001); 1.92 for the presence of the L858R mutation, as compared with a deletion in exon 19 (P=0.02); and 1.68 for the presence of the L858R mutation in paired serum DNA, as compared with the absence of the mutation (P=0.02). The most common adverse events were mild rashes and diarrhea; grade 3 cutaneous toxic effects were recorded in 16 patients (7.4%) and grade 3 diarrhea in 8 patients (3.7%).
Large-scale screening of patients with lung cancer for EGFR mutations is feasible and can have a role in decisions about treatment.
Previous, uncontrolled studies have suggested that first-line treatment with gefitinib would be efficacious in selected patients with non-small-cell lung cancer.
In this phase 3, open-label study, we randomly assigned previously untreated patients in East Asia who had advanced pulmonary adenocarcinoma and who were nonsmokers or former light smokers to receive gefitinib (250 mg per day) (609 patients) or carboplatin (at a dose calculated to produce an area under the curve of 5 or 6 mg per milliliter per minute) plus paclitaxel (200 mg per square meter of body-surface area) (608 patients). The primary end point was progression-free survival.
The 12-month rates of progression-free survival were 24.9% with gefitinib and 6.7% with carboplatin-paclitaxel. The study met its primary objective of showing the noninferiority of gefitinib and also showed its superiority, as compared with carboplatin-paclitaxel, with respect to progression-free survival in the intention-to-treat population (hazard ratio for progression or death, 0.74; 95% confidence interval [CI], 0.65 to 0.85; P<0.001). In the subgroup of 261 patients who were positive for the epidermal growth factor receptor gene (EGFR) mutation, progression-free survival was significantly longer among those who received gefitinib than among those who received carboplatin-paclitaxel (hazard ratio for progression or death, 0.48; 95% CI, 0.36 to 0.64; P<0.001), whereas in the subgroup of 176 patients who were negative for the mutation, progression-free survival was significantly longer among those who received carboplatin-paclitaxel (hazard ratio for progression or death with gefitinib, 2.85; 95% CI, 2.05 to 3.98; P<0.001). The most common adverse events were rash or acne (in 66.2% of patients) and diarrhea (46.6%) in the gefitinib group and neurotoxic effects (69.9%), neutropenia (67.1%), and alopecia (58.4%) in the carboplatin-paclitaxel group.
Gefitinib is superior to carboplatin-paclitaxel as an initial treatment for pulmonary adenocarcinoma among nonsmokers or former light smokers in East Asia. The presence in the tumor of a mutation of the EGFR gene is a strong predictor of a better outcome with gefitinib. (ClinicalTrials.gov number, NCT00322452.)
Deregulation of EGFR signaling is common in non-small cell lung cancers (NSCLC) and this finding led to the development of tyrosine kinase inhibitors (TKIs) that are highly effective in a subset of NSCLC. Mutations of EGFR (mEGFR) and copy number gains (CNGs) of EGFR (gEGFR) and HER2 (gHER2) have been reported to predict for TKI response. Mutations in KRAS (mKRAS) are associated with primary resistance to TKIs.
We investigated the relationship between mutations, CNGs and response to TKIs in a large panel of NSCLC cell lines. Genes studied were EGFR, HER2, HER3 HER4, KRAS, BRAF and PIK3CA. Mutations were detected by sequencing, while CNGs were determined by quantitative PCR (qPCR), fluorescence in situ hybridization (FISH) and array comparative genomic hybridization (aCGH). IC50 values for the TKIs gefitinib (Iressa) and erlotinib (Tarceva) were determined by MTS assay. For any of the seven genes tested, mutations (39/77, 50.6%), copy number gains (50/77, 64.9%) or either (65/77, 84.4%) were frequent in NSCLC lines. Mutations of EGFR (13%) and KRAS (24.7%) were frequent, while they were less frequent for the other genes. The three techniques for determining CNG were well correlated, and qPCR data were used for further analyses. CNGs were relatively frequent for EGFR and KRAS in adenocarcinomas. While mutations were largely mutually exclusive, CNGs were not. EGFR and KRAS mutant lines frequently demonstrated mutant allele specific imbalance i.e. the mutant form was usually in great excess compared to the wild type form. On a molar basis, sensitivity to gefitinib and erlotinib were highly correlated. Multivariate analyses led to the following results: 1. mEGFR and gEGFR and gHER2 were independent factors related to gefitinib sensitivity, in descending order of importance. 2. mKRAS was associated with increased in vitro resistance to gefitinib.
Our in vitro studies confirm and extend clinical observations and demonstrate the relative importance of both EGFR mutations and CNGs and HER2 CNGs in the sensitivity to TKIs.
Receptor tyrosine kinase genes were sequenced in non–small cell lung cancer (NSCLC) and matched normal tissue. Somatic mutations
of the epidermal growth factor receptor gene EGFR were found in 15of 58 unselected tumors from Japan and 1 of 61 from the United States. Treatment with the EGFR kinase inhibitor
gefitinib (Iressa) causes tumor regression in some patients with NSCLC, more frequently in Japan. EGFR mutations were found in additional lung cancer samples from U.S. patients who responded to gefitinib therapy and in a lung
adenocarcinoma cell line that was hypersensitive to growth inhibition by gefitinib, but not in gefitinib-insensitive tumors
or cell lines. These results suggest that EGFR mutations may predict sensitivity to gefitinib.
EGFR gene mutations and increased EGFR copy number have been associated with favorable response to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKI) in patients with non-small-cell lung cancer (NSCLC). In contrast, KRAS mutation has been shown to predict poor response to such therapy. We tested the utility of combinations of these three markers in predicting response and survival in patients with NSCLC treated with EGFR-TKIs.
Patients with advanced NSCLC treated with EGFR-TKI with available archival tissue specimens were included. EGFR and KRAS mutations were analyzed using PCR-based sequencing. EGFR copy number was analyzed using fluorescence in situ hybridization.
The study included 73 patients, 59 of whom had all three potential markers successfully analyzed. EGFR mutation was detected in 7 of 71 patients (9.8%), increased EGFR copy number in 32 of 59 (54.2%), and KRAS mutation in 16 of 70 (22.8%). EGFR mutation (P<0.0001) but not increased EGFR copy number (P=0.48) correlated with favorable response. No survival benefit was detected in patients with either of these features. KRAS mutation correlated with progressive disease (P=0.04) and shorter median time to progression (P=0.0025) but not with survival. Patients with both EGFR mutation and increased EGFR copy number had a >99.7% chance of objective response, whereas patients with KRAS mutation with or without increased EGFR copy number had a >96.5% chance of disease progression.
KRAS mutation should be included as indicator of resistance in the panel of markers used to predict response to EGFR-TKIs in NSCLC.
Although adenocarcinomas of the lung are associated with epidermal growth factor receptor (EGFR) gene mutations and sensitivity to EGFR tyrosine kinase inhibitors, it remains unclear whether bronchioloalveolar carcinoma (BAC) components and/or subtypes affect these associations. We aimed to clarify correlations between EGFR gene mutations and BAC components and to establish the histologic features as reliable predictors for the mutations. We examined 141 non-small cell lung cancers (NSCLCs), including 118 adenocarcinomas, for mutations in exons 19 and 21 of the EGFR gene together with mutations in codon 12 of the K-ras gene using loop-hybrid mobility shift assays, a highly sensitive polymerase chain reaction-based method. Adenocarcinomas were subdivided into subtypes with a nonmucinous or mucinous BAC component and those without BAC components. In NSCLCs, EGFR mutations were detected in 75 cases (53.2%) and were significantly associated with adenocarcinoma, female sex, and never smoking. Among adenocarcinomas, nonmucinous and mucinous BAC components were significantly associated with EGFR and K-ras gene mutations, respectively. Because EGFR mutations were detected even in most pure nonmucinous BACs, ie, lung adenocarcinoma in situ, EGFR mutation is considered a critical event in the pathogenesis of nonmucinous BAC tumors.
Introduction: Advances in the pathology and computed tomography (CT) of lung adenocarcinoma and bronchioloalveolar carcinoma (BAC) have demonstrated important new prognostic features that have led to changes in classification and diagnostic criteria.
Methods: The literature and a set of cases were reviewed by a pathology/CT review panel of pathologists and radiologists who met during a November 2004 International Association for the Study of Lung Cancer/American Society of Clinical Oncology consensus workshop in New York. The group addressed the question of whether sufficient data exist to modify the 2004 World Health Organization (WHO) classification of adenocarcinoma and BAC to define a minimally invasive adenocarcinoma with BAC. The problems of diffuse and/or multicentric BAC and adenocarcinoma were evaluated.
Results: The clinical concept of BAC needs to be reevaluated with careful attention to the new 2004 WHO criteria because of the major clinical implications. Existing data indicate that patients with solitary, small, peripheral BAC have a 100% 5-year survival rate. The favorable prognostic impact of the restrictive criteria for BAC is already being detected in major epidemiologic data sets such as the Surveillance Epidemiology and End-Results registry. Most lung adenocarcinomas, including those with a BAC component, are invasive and consist of a mixture of histologic patterns. Therefore, they are best classified as adenocarcinoma, mixed subtype. This applies not only to adenocarcinomas with a solitary nodule presentation but also to tumors with a diffuse/multinodular pattern. The percentage of BAC versus invasive components in lung adenocarcinomas seems to be prognostically important. However, at the present time, a consensus definition of minimally invasive BAC with a favorable prognosis was not recommended by the panel, so the 1999/2004 WHO criteria for BAC remain unchanged. In small biopsy specimens or cytology specimens, recognition of a BAC component is possible. However, it is not possible to exclude an invasive component. The diagnosis of BAC requires thorough histologic sampling of the tumor.
Conclusion: Advances in understanding of the pathology and CT features of BAC and adenocarcinoma have led to important changes in diagnostic criteria and classification of BAC and adenocarcinoma. These criteria need to be uniformly applied by pathologists, radiologists, clinicians, and researchers. The 2004 WHO classification of adenocarcinoma is readily applicable to research studies, but attention needs to be placed on the relative proportion of the adenocarcinoma subtypes. Other recently recognized prognostic features such as size of scar, size of invasive component, or pattern of invasion also seem to be important. More work is needed to determine the most important prognostic pathologic features in lung adenocarcinoma.
Background:
Epidermal growth factor receptor (EGFR) mutations play essential roles in the treatment of non-small cell lung cancer (NSCLC) patients using EGFR tyrosine kinase inhibitors. Detection of EGFR mutations in blood cell-free DNA (cfDNA) seems promising. However, the mutation status in the plasma/serum is not always consistent with that in the tissues.
Objectives:
The aims of this study were to compare the mutation statuses in plasma to those in tissues and thus to determine the specific subgroups of NSCLC patients who may be the best candidates for EGFR mutation analyses using blood cfDNA.
Methods:
A total of 111 pairs of tissue and plasma samples were collected. Mutant-enriched PCR and sequencing analyses were performed to detect EGFR exon 19 deletions and exon 21 L858R mutations.
Results:
Mutations were discovered in 43.2% (48/111) of the patients. The overall rate of consistency of the EGFR mutation statuses for the 111 paired plasma and tissue samples was 71.2% (79/111). The sensitivity and specificity rates of detecting EGFR mutations in the plasma were 35.6% (16/45) and 95.5% (63/66), respectively. The disease stage and tumor differentiation subgroups showed significantly different detection sensitivities; the sensitivity was 10% in early-stage patients and 56% in advanced-stage patients (p = 0.0014). For patients with poorly differentiated tumors, the sensitivity was 77.8%, which was significantly different from those with highly differentiated (20%; p = 0.0230) and moderately differentiated tumors (19%; p = 0.0042).
Conclusion:
Blood analyses for EGFR mutations may be effectively used in advanced-stage patients or patients with poorly differentiated tumors.
Activating mutations in EGFR are important markers of response to tyrosine kinase inhibitor (TKI) therapy in non-small-cell lung cancer (NSCLC). The OPTIMAL study compared efficacy and tolerability of the TKI erlotinib versus standard chemotherapy in the first-line treatment of patients with advanced EGFR mutation-positive NSCLC.
We undertook an open-label, randomised, phase 3 trial at 22 centres in China. Patients older than 18 years with histologically confirmed stage IIIB or IV NSCLC and a confirmed activating mutation of EGFR (exon 19 deletion or exon 21 L858R point mutation) received either oral erlotinib (150 mg/day) until disease progression or unacceptable toxic effects, or up to four cycles of gemcitabine plus carboplatin. Patients were randomly assigned (1:1) with a minimisation procedure and were stratified according to EGFR mutation type, histological subtype (adenocarcinoma vs non-adenocarcinoma), and smoking status. The primary outcome was progression-free survival, analysed in patients with confirmed disease who received at least one dose of study treatment. The trial is registered at ClinicalTrials.gov, number NCT00874419, and has completed enrolment; patients are still in follow-up.
83 patients were randomly assigned to receive erlotinib and 82 to receive gemcitabine plus carboplatin; 82 in the erlotinib group and 72 in the chemotherapy group were included in analysis of the primary endpoint. Median progression-free survival was significantly longer in erlotinib-treated patients than in those on chemotherapy (13.1 [95% CI 10.58-16.53] vs 4.6 [4.21-5.42] months; hazard ratio 0.16, 95% CI 0.10-0.26; p<0.0001). Chemotherapy was associated with more grade 3 or 4 toxic effects than was erlotinib (including neutropenia in 30 [42%] of 72 patients and thrombocytopenia in 29 [40%] patients on chemotherapy vs no patients with either event on erlotinib); the most common grade 3 or 4 toxic effects with erlotinib were increased alanine aminotransferase concentrations (three [4%] of 83 patients) and skin rash (two [2%] patients). Chemotherapy was also associated with increased treatment-related serious adverse events (ten [14%] of 72 patients [decreased platelet count, n=8; decreased neutrophil count, n=1; hepatic dysfunction, n=1] vs two [2%] of 83 patients [both hepatic dysfunction]).
Compared with standard chemotherapy, erlotinib conferred a significant progression-free survival benefit in patients with advanced EGFR mutation-positive NSCLC and was associated with more favourable tolerability. These findings suggest that erlotinib is important for first-line treatment of patients with advanced EGFR mutation-positive NSCLC.
F Hoffmann-La Roche Ltd (China); Science and Technology Commission of Shanghai Municipality.
We evaluated EGFR and KRAS mutations between 37 paired primary tumors and corresponding metastases in lung adenocarcinoma. A substantial discordance was found in EGFR mutation status between primary tumors and corresponding metastases including pleural metastases. Moreover, the responsiveness to EGFR tyrosine kinase inhibitors tend to be correlated with EGFR mutation status in metastatic lesions than in primary tumors.
The aim of this study was to compare epidermal growth factor receptor (EGFR) and KRAS mutations between primary tumors and corresponding metastases including pleural metastases in lung adenocarcinoma.
Thirty-seven paired primary lung adenocarcinomas and corresponding metastatic tumors were analyzed for EGFR and KRAS mutations. In addition, 21 pleural metastases including malignant pleural effusion or pleural biopsy were used in performing these mutation analyses.
EGFR mutations were detected in 18 primary lung adenocarcinomas (48.6%) and in 16 corresponding metastases (43.2%). EGFR mutations showed a discordance rate of 16.2% (6 of 37 patients) between primary lung adenocarcinomas and corresponding metastases. Among 21 pleural metastases, 3 patients (14.3%) showed that the EGFR mutation was discordant. KRAS mutations were detected in one primary tumor and in two metastatic tumors. Eighteen patients were treated with EGFR tyrosine kinase inhibitors. One of seven patients who experienced partial response had EGFR mutations only in the metastasis, and two of seven patients who experienced progressive disease carried wild-type EGFR only in the metastasis.
EGFR mutations were discordant between primary tumors and corresponding metastases in a significant portion of lung adenocarcinomas. Furthermore, these discordance was also observed in metastases to the pleura, the nearest metastatic site.
EGFR mutations now guide the clinical use of EGFR-targeted therapy in lung cancer. However, standard EGFR mutation analysis requires a minimum amount of tumor tissue, which may not be available in certain situations. In this study, we combined a mass spectrometry genotyping assay (Sequenom) with a mutant-enriched PCR (ME-PCR) to detect EGFR mutations in free plasma DNA from patients with lung cancer.
DNAs were extracted from 31 plasma samples from 31 patients and analyzed by both methods for EGFR Exon 19 deletion and EGFR L858R mutation. Results in plasma DNA samples were compared with EGFR mutation status obtained in tumor DNA (18/31 EGFR mutant). The relationship of EGFR mutation status in tumor and/or plasma samples to overall survival was assessed.
The EGFR mutation status in plasma DNA was identical to the primary tumor in 61% of patients (19/31). By mass spectrometry genotyping, the plasma samples contained mutant DNA corresponding to 5/14 EGFR Exon 19 deletions and 3/4 EGFR L858R mutations previously diagnosed in the matched tumors. Two samples were positive in plasma DNA but negative in primary tumor tissue. Results were similar for samples studied by ME-PCR. For patients treated with erlotinib, overall survival was correlated with the presence of EGFR mutation in plasma and/or tumor tissue (p=0.002), with the two patients positive only in plasma DNA showing responses and favorable outcomes.
The detection of EGFR mutations in plasma DNA samples by mass spectrometry genotyping and ME-PCR is feasible. A positive EGFR result in plasma DNA has a high predictive value for tumor EGFR status and for favorable clinical course on EGFR-targeted therapy and could therefore be useful in guiding clinical decisions in patients with insufficient or unavailable tumor specimens.
Purpose
The anti–epidermal growth factor receptor (EGFR) antibody cetuximab is efficacious in multiple tumor types. Patient selection with markers predictive of benefit may enhance its therapeutic index. This retrospective, correlative analysis of the phase III trial BMS099 of cetuximab in advanced non–small-cell lung cancer (NSCLC) was conducted to identify molecular markers for the selection of patients most likely to benefit from cetuximab.
Methods
In BMS099, 676 chemotherapy-naïve patients with stage IIIB (pleural effusion) or stage IV NSCLC of any histology or EGFR expression status were randomly assigned to taxane/carboplatin (T/C) with or without cetuximab. Biomarkers analyzed included K-Ras and EGFR mutations by direct sequencing, EGFR protein expression by immunohistochemistry (IHC), and EGFR gene copy number by fluorescent in situ hybridization (FISH). Relationships between biomarker status and progression-free survival (PFS), overall survival (OS), and overall response rate (ORR) were assessed by log-rank tests per treatment arm for treatment-specific effects and across the total evaluable population.
Results
Tumor samples were available from 225 randomly assigned patients. K-Ras mutations were found in 17% of evaluable patients (35 of 202 patients), EGFR mutations were found in 10% (17 of 166 patients), EGFR positivity by IHC was found in 89% (131 of 148 patients), and FISH positivity was found in 52% (54 of 104 patients). No significant associations were found between biomarker status and PFS, OS, and ORR in the treatment-specific analyses.
Conclusion
In contrast with colorectal cancer, and within the limitations of the data set, efficacy parameters did not appear to correlate with K-Ras mutation status or with any of the EGFR-related biomarkers evaluated. Additional exploratory analyses are essential to identify predictive markers and to optimize patient selection for cetuximab therapy in NSCLC.
Mutations in the epidermal growth factor receptor (EGFR) kinase domain can predict tumor response to tyrosine kinase inhibitors (TKIs) in non-small-cell lung cancer (NSCLC). However, obtaining tumor tissues for mutation analysis is challenging. We hypothesized that plasma-based EGFR mutation analysis is feasible and has value in predicting tumor response in patients with NSCLC.
Plasma DNA samples and matched tumors from 230 patients with stages IIIB to IV NSCLC were analyzed for EGFR mutations in exons 19 and 21 by using denaturing high-performance liquid chromatography. We compared the mutations in the plasma samples and the matched tumors and determined an association between EGFR mutation status and the patients' clinical outcomes prospectively.
In 230 patients, we detected 81 EGFR mutations in 79 (34.3%) of the patients' plasma samples. We detected the same mutations in 63 (79.7%) of the matched tumors. Sixteen plasma (7.0%) and fourteen tumor (6.1%) samples showed unique mutations. The mutation frequencies were significantly higher in never-smokers and in patients with adenocarcinomas (P = .012 and P = .009, respectively). In the 102 patients who failed platinum-based treatment and who were treated with gefitinib, 22 (59.5%) of the 37 with EGFR mutations in the plasma samples, whereas only 15 (23.1%) of the 65 without EGFR mutations, achieved an objective response (P = .002). Patients with EGFR mutations had a significantly longer progression-free survival time than those without mutations (P = .044) in plasma.
EGFR mutations can be reliably detected in plasma DNA of patients with stages IIIB to IV NSCLC and can be used as a biomarker to predict tumor response to TKIs.
Use of cetuximab, a monoclonal antibody targeting the epidermal growth factor receptor (EGFR), has the potential to increase survival in patients with advanced non-small-cell lung cancer. We therefore compared chemotherapy plus cetuximab with chemotherapy alone in patients with advanced EGFR-positive non-small-cell lung cancer.
In a multinational, multicentre, open-label, phase III trial, chemotherapy-naive patients (>or=18 years) with advanced EGFR-expressing histologically or cytologically proven stage wet IIIB or stage IV non-small-cell lung cancer were randomly assigned in a 1:1 ratio to chemotherapy plus cetuximab or just chemotherapy. Chemotherapy was cisplatin 80 mg/m(2) intravenous infusion on day 1, and vinorelbine 25 mg/m(2) intravenous infusion on days 1 and 8 of every 3-week cycle) for up to six cycles. Cetuximab-at a starting dose of 400 mg/m(2) intravenous infusion over 2 h on day 1, and from day 8 onwards at 250 mg/m(2) over 1 h per week-was continued after the end of chemotherapy until disease progression or unacceptable toxicity had occurred. The primary endpoint was overall survival. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00148798.
Between October, 2004, and January, 2006, 1125 patients were randomly assigned to chemotherapy plus cetuximab (n=557) or chemotherapy alone (n=568). Patients given chemotherapy plus cetuximab survived longer than those in the chemotherapy-alone group (median 11.3 months vs 10.1 months; hazard ratio for death 0.871 [95% CI 0.762-0.996]; p=0.044). The main cetuximab-related adverse event was acne-like rash (57 [10%] of 548, grade 3).
Addition of cetuximab to platinum-based chemotherapy represents a new treatment option for patients with advanced non-small-cell lung cancer.
Merck KGaA.
Some patients with non-small cell lung cancer (NSCLC) respond well to therapy with tyrosine kinase inhibitors (TKI). Somatic mutation of the epidermal growth factor receptor (EGFR) gene is an important predictive marker for TKI response.
We performed EGFR mutation analysis in 307 NSCLC (exon 18-21). The data were analyzed for associations with clinical-pathological parameters.
Relevant EGFR mutations were found in 25/307 NSCLC (8.1%; 178 biopsies and 129 cytologies). Most mutations were found in exon 19 (50%) followed by the L858R point mutation in exon 21 (12.5%). EGFR mutations were significantly more common in women than in men (16.8% vs. 2.7%; p<0.001) and in adenocarcinoma than in other carcinoma subtypes (11.4% vs. 3.8%; p=0.017). EGFR mutation was associated with TTF-1 positivity (p<0.041). Almost all (96%) mutated NSCLC were TTF-1 positive.
In Central Europe, the prevalence of relevant EGFR mutations in NSCLC is <10% of patients with NSCLC. EGFR mutations are more common in women and TTF-1 positive adenocarcinomas. Mutation analysis can be performed both from biopsies and cytologies.
Relationships between clinical outcomes and epidermal growth factor receptor (EGFR)-related tumor markers were investigated in patients with advanced non-small cell lung cancer.
Patients with stage IIIB/IV non-small cell lung cancer (0-2 prior regimens) received erlotinib (150 mg PO per day). Response and survival were evaluated, and tumor samples were assessed by immunohistochemistry (EGFR, phosphorylated mitogen-activated protein kinase, and phosphorylated AKT protein expression), fluorescence in situ hybridization (FISH; EGFR gene copy number), and DNA sequencing (EGFR, KRAS gene mutations).
Among 311 patients, 8% had a complete/partial response; the disease control rate was 66%. Median Overall survival (OS) was 6.1 months; 1-year survival rate was 27.2%. Two of 4 patients with EGFR mutations had tumor responses, versus 2/68 with wild-type EGFR (p = 0.014). Progression-free survival (PFS) (HR = 0.31) and OS (HR = 0.33) were significantly prolonged in patients with EGFR mutations. Response rate was significantly higher in patients with EGFR FISH-positive (17%) than FISH-negative tumors (6%), and both PFS (HR = 0.58) and OS (HR = 0.63) significantly favored patients with EGFR FISH-positive tumors; median OS was 8.6 months in the EGFR FISH-positive group. None of 17 patients with a KRAS mutation had a tumor response, but the impact of KRAS mutation status on survival outcomes was of borderline statistical significance. Neither phosphorylated mitogen-activated protein kinase nor phosphorylated AKT immunohistochemistry status had a significant effect on PFS and OS with erlotinib.
The presence of EGFR mutations and EGFR FISH-positive tumors may predispose patients to achieving better outcomes on erlotinib, but may have a beneficial impact on prognosis (irrespective of treatment). Prospective, placebo-controlled studies are needed to determine the predictive value of the putative biomarkers.
A new method for determining nucleotide sequences in DNA is described. It is similar to the "plus and minus" method [Sanger, F. & Coulson, A. R. (1975) J. Mol. Biol. 94, 441-448] but makes use of the 2',3'-dideoxy and arabinonucleoside analogues of the normal deoxynucleoside triphosphates, which act as specific chain-terminating inhibitors of DNA polymerase. The technique has been applied to the DNA of bacteriophage varphiX174 and is more rapid and more accurate than either the plus or the minus method.
Most patients with non-small-cell lung cancer have no response to the tyrosine kinase inhibitor gefitinib, which targets the epidermal growth factor receptor (EGFR). However, about 10 percent of patients have a rapid and often dramatic clinical response. The molecular mechanisms underlying sensitivity to gefitinib are unknown.
We searched for mutations in the EGFR gene in primary tumors from patients with non-small-cell lung cancer who had a response to gefitinib, those who did not have a response, and those who had not been exposed to gefitinib. The functional consequences of identified mutations were evaluated after the mutant proteins were expressed in cultured cells.
Somatic mutations were identified in the tyrosine kinase domain of the EGFR gene in eight of nine patients with gefitinib-responsive lung cancer, as compared with none of the seven patients with no response (P<0.001). Mutations were either small, in-frame deletions or amino acid substitutions clustered around the ATP-binding pocket of the tyrosine kinase domain. Similar mutations were detected in tumors from 2 of 25 patients with primary non-small-cell lung cancer who had not been exposed to gefitinib (8 percent). All mutations were heterozygous, and identical mutations were observed in multiple patients, suggesting an additive specific gain of function. In vitro, EGFR mutants demonstrated enhanced tyrosine kinase activity in response to epidermal growth factor and increased sensitivity to inhibition by gefitinib.
A subgroup of patients with non-small-cell lung cancer have specific mutations in the EGFR gene, which correlate with clinical responsiveness to the tyrosine kinase inhibitor gefitinib. These mutations lead to increased growth factor signaling and confer susceptibility to the inhibitor. Screening for such mutations in lung cancers may identify patients who will have a response to gefitinib.
Gefitinib (Iressa, Astra Zeneca Pharmaceuticals) is a tyrosine kinase inhibitor that targets the epidermal growth factor receptor
(EGFR) and induces dramatic clinical responses in nonsmall cell lung cancers (NSCLCs) with activating mutations within the
EGFR kinase domain. We report that these mutant EGFRs selectively activate Akt and signal transduction and activator of transcription
(STAT) signaling pathways, which promote cell survival, but have no effect on extracellular signal–regulated kinase signaling,
which induces proliferation. NSCLC cells expressing mutant EGFRs underwent extensive apoptosis after small interfering RNA–mediated
knockdown of the mutant EGFR or treatment with pharmacological inhibitors of Akt and STAT signaling and were relatively resistant to apoptosis induced
by conventional chemotherapeutic drugs. Thus, mutant EGFRs selectively transduce survival signals on which NSCLCs become dependent;
inhibition of those signals by gefitinib may contribute to the drug's efficacy.
Recent reports have suggested influences of racial difference on the frequency of mutation of EGFR in lung cancer. We therefore sought to characterize the frequency and pattern of mutation of EGFR in lung adenocarcinoma in Thai patients. Overall, EGFR catalytic domain mutations were detected in 35/61 (57.4%). We found 29/60 (48.3%) of exon 19 deletions, 5/54 (9.3%) of exon 21 point mutations, and 1/54 (1.9%) of double-mutation of both exons. The presence of these mutations was significantly associated with non-smoking habit. In summary, we report a strikingly high prevalence of mutation of EGFR in Thai lung adenocarcinoma, which may explain the high response rate to the treatment with TKI among Asian populations.
In this issue of Clinical Cancer Research , Kimura et al. ([1][1]) report on a blood-based assay to detect epidermal growth factor receptor (EGFR) mutations in patients with advanced non–small cell lung cancer (NSCLC).
The development of effective molecular therapeutic targeting strategies in
Somatic mutations in certain tyrosine kinases have emerged as central 'drivers' of specific cancers and these mutant proteins are proving to be excellent substrates for targeted therapies. This is the case for mutant EGFR-dependent lung adenocarcinomas, where EGFR mutation testing is already being used to help guide treatment decisions. Here, we provide an overview of the biology of EGFR-targeted therapies and the clinical experience to date, the positive and negative predictors of response, pathologic correlates of EGFR-mutant status, testing methods to establish patient eligibility for these agents, and the basis for primary and secondary resistance.
EGF receptor gene mutations are common in lung cancers from 'never smokers' and are associated with sensitivity of tumors to gefitinib and erlotinib
- W Pao
- V Miller
- M Zakowski
- J Doherty
- K Politi
- I Sarkaria
Pao W, Miller V, Zakowski M, Doherty J, Politi K, Sarkaria I, et al. (2004). EGF
receptor gene mutations are common in lung cancers from 'never smokers'
and are associated with sensitivity of tumors to gefitinib and erlotinib. Proc
Natl Acad Sci USA 101:13306-13311.
- A Jemal
- R Siegel
- J Xu
- E Wade
Jemal A, Siegel R, Xu J, Wade E (2010). Cancer statistics, 2010. CA Cancer J
Clin 60:277-300.