[Show abstract][Hide abstract] ABSTRACT: Background:
The 5-year cancer specific survival (CSS) for patients with muscle invasive urothelial carcinoma of the bladder (MIBC) treated with cystectomy alone is approximately 50%. Platinum based neoadjuvant chemotherapy (NAC) plus cystectomy results in a marginal 5-10% increase in 5-year CSS in MIBC. Interestingly, responders to NAC (<ypT2) have a 5-year CSS of 90% which is in stark contrast to the 30-40% CSS for those whose MIBC is resistance to NAC. While the implementation of NAC for MIBC is increasing, it is still not widely utilized due to concerns related to delay of cystectomy, potential side-effects, and inability to predict effectiveness. Recently suggested molecular signatures of chemoresponsiveness, which could prove useful in this setting, would be of considerable utility but are yet to be translated into clinical practice.
mRNA expression data from a prior report on a NAC-treated MIBC cohort were re-analyzed in conjunction with the antibody database of the Human Protein Atlas (HPA) to identify candidate protein based biomarkers detectable by immunohistochemistry (IHC). These candidate biomarkers were subsequently tested in tissue microarrays derived from an independent cohort of NAC naive MIBC biopsy specimens from whom the patients were treated with neoadjuvant gemcitabine cisplatin NAC and subsequent cystectomy. The clinical parameters that have been previously associated with NAC response were also examined in our cohort.
Our analyses of the available mRNA gene expression data in a discovery cohort (n = 33) and the HPA resulted in 8 candidate protein biomarkers. The combination of GDPD3 and SPRED1 resulted in a multivariate classification tree that was significantly associated with NAC response status (Goodman-Kruskal γ = 0.85 p<0.0001) in our independent NAC treated MIBC cohort. This model was independent of the clinical factors of age and clinical tumor stage, which have been previously associated with NAC response by our group. The combination of both these protein biomarkers detected by IHC in biopsy specimens along with the relevant clinical parameters resulted in a prediction model able to significantly stratify the likelihood of NAC resistance in our cohort (n = 37) into two well separated halves: low-26% n = 19 and high-89% n = 18, Fisher's exact p = 0.0002).
We illustrate the feasibility of translating a gene expression signature of NAC response from a discovery cohort into immunohistochemical markers readily applicable to MIBC biopsy specimens in our independent cohort. The results from this study are being characterized in additional validation cohorts. Additionally, we anticipate that emerging somatic mutations in MIBC will also be important for NAC response prediction. The relationship of the findings in this study to the current understanding of variant histologic subtypes of MIBC along with the evolving molecular subtypes of MIBC as it relates to NAC response remains to be fully characterized.
PLoS ONE 07/2015; 10(7). DOI:10.1371/journal.pone.0131245 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Prostate cancer is the most prevalently diagnosed and the second cause of cancer-related death in North American men. Several approaches have been proposed to augment detection of prostate cancer using different imaging modalities. Due to advantages of ultrasound imaging, these approaches have been the subject of several recent studies. This paper presents the results of a feasibility study on differentiating between lower and higher grade prostate cancer using ultrasound RF time series data. We also propose new spectral features of RF time series to highlight aggressive prostate cancer in small ROIs of size 1 mm × 1 mm in a cohort of 19 ex vivo specimens of human prostate tissue. In leave-one-patient-out cross-validation strategy, an area under accumulated ROC curve of 0.8 has been achieved with overall sensitivity and specificity of 81% and 80%, respectively. The current method shows promising results on differentiating between lower and higher grade of prostate cancer using ultrasound RF time series.
[Show abstract][Hide abstract] ABSTRACT: Inflammation is associated with several diseases of the prostate including benign enlargement and cancer, but a causal relationship has not been established. Our objective was to characterize the prostate inflammatory microenvironment after infection with a human prostate derived bacterial strain and to determine the effect of inflammation on prostate cancer progression. To this end, we mimicked typical human prostate infection with retrograde urethral instillation of CP1, a human prostatic isolate of Escherichia coli. CP1 bacteria were tropic for the accessory sex glands and induced acute inflammation in the prostate and seminal vesicles with chronic inflammation lasting at least one year. Compared to controls, infection induced both acute and chronic inflammation with epithelial hyperplasia, stromal hyperplasia, and inflammatory cell infiltrates. In areas of inflammation, epithelial proliferation and hyperplasia often persist despite decreased expression of androgen receptor (AR). Inflammatory cells in the prostates of CP1 infected mice were characterized at 8 weeks post-infection by flow cytometry, which showed an increase in macrophages and lymphocytes, particularly Th17 cells. Inflammation was additionally assessed in the context of carcinogenesis. Multiplex cytokine profiles of inflamed prostates showed distinct inflammatory cytokines were expressed during prostate inflammation and cancer, with a subset of cytokines synergistically increased during concurrent inflammation and cancer. Furthermore, CP1 infection in the Hi-Myc mouse model of prostate cancer accelerated the development of invasive prostate adenocarcinoma with 70% more mice developing cancer by 4.5 months of age. This study provides direct evidence that prostate inflammation accelerates prostate cancer progression, and gives insight into the microenvironment changes induced by inflammation that may accelerate tumour initiation or progression.
The Journal of Pathology 10/2014; 235(3). DOI:10.1002/path.4472 · 7.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives
To investigate reporting patterns and outcomes associated with lymphovascular invasion in a general population setting.Methods
We identified all cystectomy patients with muscle-invasive urothelial cancer in Ontario, Canada, 1994–2008. Surgical pathology reports were analyzed for pathological variables including lymphovascular invasion. Lymphovascular invasion reporting patterns were described over time. A Cox proportional hazards model was used to evaluate the association of lymphovascular invasion with survival.ResultsOf the 2802 cases identified, lymphovascular invasion status was reported in 75%. Lymphovascular invasion reporting significantly improved over the study period and was correlated with poor prognostic pathological features (T stage and N stage). Comprehensive cancer center status was not consistently associated with lymphovascular invasion reporting. Patients with lymphovascular invasion had substantially lower survival than patients who were lymphovascular invasion-negative or whose lymphovascular invasion status was unstated (P < 0.001). Lymphovascular invasion was independently associated with survival in patients regardless of lymph node metastasis. After adjusting for age, stage, comorbidity, margin status and adjuvant chemotherapy, lymphovascular invasion remained strongly associated with reduced survival (hazard ratio 1.98, 95% confidence interval 1.71–2.29).Conclusions
Although routine reporting of lymphovascular invasion has improved over the years, pathologists appear to be biased towards evaluating lymphovascular invasion in patients with high-stage disease. Despite this bias, lymphovascular invasion remains an important prognostic factor among patients treated by cystectomy. Pathologists in general practice should report lymphovascular invasion status more consistently and urologists should hold their pathology colleagues to a higher standard.
International Journal of Urology 10/2014; 22(2). DOI:10.1111/iju.12611 · 2.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Anaplastic lymphoma kinase (ALK) genomic alterations have emerged as a potent predictor of benefit from treatment with ALK inhibitors in several cancers. Currently, there is no information about ALK gene alterations in urothelial carcinoma (UC) and its correlation with clinical or pathologic features and outcome.
Samples from patients with advanced UC and correlative clinical data were collected. Genomic imbalances were investigated by array comparative genomic hybridization (aCGH). ALK gene status was evaluated by fluorescence in situ hybridization (FISH). ALK expression was assessed by immunohistochemistry (IHC) and high-throughput mutation analysis with Oncomap 3 platform. Next generation sequencing was performed using Illumina Genome Analyzer IIx, and Illumina HiSeq 2000 in the FISH positive case.
70 of 96 patients had tissue available for all the tests performed. Arm level copy number gains at chromosome 2 were identified in 17 (24%) patients. Minor copy number alterations (CNAs) in the proximity of ALK locus were found in 3 patients by aCGH. By FISH analysis, one of these samples had a deletion of the 5′ALK. Whole genome next generation sequencing was inconclusive to confirm the deletion at the level of the ALK gene at the coverage level used. We did not observe an association between ALK CNA and overall survival, ECOG PS, or development of visceral disease.
ALK genomic alterations are rare and probably without prognostic implications in UC. The potential for testing ALK inhibitors in UC merits further investigation but might be restricted to the identification of an enriched population.
PLoS ONE 08/2014; 9(8):e103325. DOI:10.1371/journal.pone.0103325 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective
To evaluate whether pathologic factors are associated with differential effect of ACT.Patients and Methods
In this population-based retrospective cohort study we linked electronic records of treatment and surgical pathology to the Ontario Cancer Registry. The study population included all patients with MIBC undergoing cystectomy in Ontario 1994-2008. Factors associated with overall (OS) and cancer-specific survival (CSS) were evaluated using Cox proportional hazards. We tested for interaction between the following variables and ACT effect-size: N stage, margin status, T stage, and lymphovascular invasion (LVI).ResultsThe study population included 2802 patients; 19% were treated with ACT. Interaction terms with ACT for OS/CSS are: N stage (p<0.001/p<0.001); margin status (p=0.054/p=0.048); T stage (p=0.509/p=0.286); and LVI (p=0.361/p=0.405). Magnitude of effect for ACT was greater for patients with node-positive disease (OS HR 0.56, [95%CI 0.47-0.67], CSS HR 0.60 [0.49-0.72]) than for patients with node-negative disease (OS HR 0.80 [0.61-1.03], CSS HR 0.79 [0.59-1.07]). ACT was also associated with greater effect among patients with involved margins (OS HR 0.45 [95%CI 0.33-0.62], CSS HR 0.40 [0.28-0.57]) compared to patients with negative margins (OS HR 0.75 [0.65-0.87], CSS HR 0.79 [0.67-0.93]).Conclusions
In this population-based cohort study we observe evidence of interaction between ACT effect and nodal stage and surgical margin status. Our results suggest that patients at highest risk of disease recurrence may derive greatest benefit from ACT.
BJU International 08/2014; 116(3). DOI:10.1111/bju.12913 · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Metaplasia can result when injury reactivates latent developmental signaling pathways that determine cell phenotype. Barrett's esophagus is a squamous-to-columnar epithelial metaplasia caused by reflux esophagitis. Hedgehog (Hh) signaling is active in columnar-lined, embryonic esophagus and inactive in squamous-lined, adult esophagus. We showed previously that Hh signaling is reactivated in Barrett's metaplasia and overexpression of Sonic hedgehog (SHH) in mouse esophageal squamous epithelium leads to a columnar phenotype. Here, our objective was to identify Hh target genes involved in Barrett's pathogenesis. By microarray analysis, we found that the transcription factor Foxa2 is more highly expressed in murine embryonic esophagus compared with postnatal esophagus. Conditional activation of Shh in mouse esophageal epithelium induced FOXA2, while FOXA2 expression was reduced in Shh knockout embryos, establishing Foxa2 as an esophageal Hh target gene. Evaluation of patient samples revealed FOXA2 expression in Barrett's metaplasia, dysplasia, and adenocarcinoma but not in esophageal squamous epithelium or squamous cell carcinoma. In esophageal squamous cell lines, Hh signaling upregulated FOXA2, which induced expression of MUC2, an intestinal mucin found in Barrett's esophagus, and the MUC2-processing protein AGR2. Together, these data indicate that Hh signaling induces expression of genes that determine an intestinal phenotype in esophageal squamous epithelial cells and may contribute to the development of Barrett's metaplasia.
[Show abstract][Hide abstract] ABSTRACT: While fibroblast growth factor receptor 3 (FGFR3) is frequently mutated or overexpressed in nonmuscle-invasive urothelial carcinoma (UC), the prevalence of FGFR3 protein expression and mutation remains unknown in muscle-invasive disease. FGFR3 protein and mRNA expression, mutational status, and copy number variation were retrospectively analyzed in 231 patients with formalin-fixed paraffin-embedded primary UCs, 33 metastases, and 14 paired primary and metastatic tumors using the following methods: immunohistochemistry, NanoString nCounterTM, OncoMap or Affymetrix OncoScanTM array, and Gain and Loss of Analysis of DNA and Genomic Identification of Significant Targets in Cancer software. FGFR3 immunohistochemistry staining was present in 29% of primary UCs and 49% of metastases and did not impact overall survival (P = 0.89, primary tumors; P = 0.78, metastases). FGFR3 mutations were observed in 2% of primary tumors and 9% of metastases. Mutant tumors expressed higher levels of FGFR3 mRNA than wild-type tumors (P < 0.001). FGFR3 copy number gain and loss were rare events in primary and metastatic tumors (0.8% each; 3.0% and 12.3%, respectively). FGFR3 immunohistochemistry staining is present in one third of primary muscle-invasive UCs and half of metastases, while FGFR3 mutations and copy number changes are relatively uncommon.
Cancer Medicine 08/2014; 3(4). DOI:10.1002/cam4.262 · 2.50 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
Key challenges of biopsy-based determination of prostate cancer aggressiveness include tumour heterogeneity, biopsy-sampling error, and variations in biopsy interpretation. The resulting uncertainty in risk assessment leads to significant overtreatment, with associated costs and morbidity. We developed a performance-based strategy to identify protein biomarkers predictive of prostate cancer aggressiveness and lethality regardless of biopsy-sampling variation.
Prostatectomy samples from a large patient cohort with long follow-up were blindly assessed by expert pathologists who identified the tissue regions with the highest and lowest Gleason grade from each patient. To simulate biopsy-sampling error, a core from a high- and a low-Gleason area from each patient sample was used to generate a 'high' and a 'low' tumour microarray, respectively.
Using a quantitative proteomics approach, we identified from 160 candidates 12 biomarkers that predicted prostate cancer aggressiveness (surgical Gleason and TNM stage) and lethal outcome robustly in both high- and low-Gleason areas. Conversely, a previously reported lethal outcome-predictive marker signature for prostatectomy tissue was unable to perform under circumstances of maximal sampling error.
Our results have important implications for cancer biomarker discovery in general and development of a sampling error-resistant clinical biopsy test for prediction of prostate cancer aggressiveness.
British Journal of Cancer 07/2014; 111(6). DOI:10.1038/bjc.2014.396 · 4.84 Impact Factor