Background: Customizing chemotherapy on the basis of chemosentitivity prediction may improve outcome in advanced bladder cancer patients. Since DNA damaging agents are the cornerstones of therapy, we hypothesized that levels of DNA repair genes could predict survival. Patients and methods: Messenger RNA expression levels of excision repair cross complementing 1 (ERCC1), breast cancer 1 (BRCA1), ribonucleotide reductase subunit M1 (RRM1) and caveolin-1 were determined by RT-PCR in tumor DNA from 57 advanced and metastatic bladder cancer patients treated with either gemcitabine/cisplatin or gemcitabine/cisplatin/paclitaxel (Taxol). Levels were correlated with survival, time to disease progression and chemotherapy response. Results: Median survival was significantly higher in patients with low ERCC1 levels (25.4 versus 15.4 months; P = 0.03) (median follow-up 19 months). A trend towards longer time to progression was observed in patients with tumors expressing low levels of all markers. Levels of RRM1, BRCA1 and caveolin-1, however, failed to predict the survival and a clear link with chemotherapy response could not be established. On multivariate analysis with pretreatment prognostic factors, ERCC1 emerged as an independent predictive factor for survival. Conclusion: The results of the study indicate that ERCC1 may predict survival in bladder cancer treated by platinum-based therapy.

There is an urgent need to identify biomarkers to guide personalized therapy in castration-resistant prostate cancer (CRPC). We aimed to clinically qualify androgen receptor (AR) gene status measurement in plasma DNA using multiplex droplet digital PCR (ddPCR) in pre- and post-chemotherapy CRPC. We optimized ddPCR assays for AR copy number and mutations and retrospectively analyzed plasma DNA from patients recruited to one of the three biomarker protocols with prospectively collected clinical data. We evaluated associations between plasma AR and overall survival (OS) and progression-free survival (PFS) in 73 chemotherapy-naïve and 98 post-docetaxel CRPC patients treated with enzalutamide or abiraterone (Primary cohort) and 94 chemotherapy-naïve patients treated with enzalutamide (Secondary cohort; PREMIERE trial). In the primary cohort, AR gain was observed in 10 (14%) chemotherapy-naïve and 33 (34%) post-docetaxel patients and associated with worse OS [hazard ratio (HR), 3.98; 95% CI 1.74–9.10; P < 0.001 and HR 3.81; 95% CI 2.28–6.37; P < 0.001, respectively], PFS (HR 2.18; 95% CI 1.08–4.39; P = 0.03, and HR 1.95; 95% CI 1.23–3.11; P = 0.01, respectively) and rate of PSA decline ≥50% [odds ratio (OR), 4.7; 95% CI 1.17–19.17; P = 0.035 and OR, 5.0; 95% CI 1.70–14.91; P = 0.003, respectively]. AR mutations [2105T>A (p.L702H) and 2632A>G (p.T878A)] were observed in eight (11%) post-docetaxel but no chemotherapy-naïve abiraterone-treated patients and were also associated with worse OS (HR 3.26; 95% CI 1.47–not reached; P = 0.004). There was no interaction between AR and docetaxel status (P = 0.83 for OS, P = 0.99 for PFS). In the PREMIERE trial, 11 patients (12%) with AR gain had worse PSA-PFS (sPFS) (HR 4.33; 95% CI 1.94–9.68; P < 0.001), radiographic-PFS (rPFS) (HR 8.06; 95% CI 3.26–19.93; P < 0.001) and OS (HR 11.08; 95% CI 2.16–56.95; P = 0.004). Plasma AR was an independent predictor of outcome on multivariable analyses in both cohorts. Plasma AR status assessment using ddPCR identifies CRPC with worse outcome to enzalutamide or abiraterone. Prospective evaluation of treatment decisions based on plasma AR is now required. NCT02288936 (PREMIERE trial).

Molecular characterization of radical prostatectomy specimens after systemic therapy may identify a gene expression profile for resistance to therapy. This study assessed tumor cells from patients with prostate cancer participating in a phase II neoadjuvant docetaxel and androgen deprivation trial to identify mediators of resistance. Transcriptional level of 93 genes from a docetaxel-resistant prostate cancer cell lines microarray study was analyzed by TaqMan low-density arrays in tumors from patients with high-risk localized prostate cancer (36 surgically treated, 28 with neoadjuvant docetaxel + androgen deprivation). Gene expression was compared between groups and correlated with clinical outcome. VIM, AR and RELA were validated by immunohistochemistry. CD44 and ZEB1 expression was tested by immunofluorescence in cells and tumor samples. Parental and docetaxel-resistant castration-resistant prostate cancer cell lines were tested for epithelial-to-mesenchymal transition (EMT) markers before and after docetaxel exposure. Reversion of EMT phenotype was investigated as a docetaxel resistance reversion strategy. Expression of 63 (67.7%) genes differed between groups (P < 0.05), including genes related to androgen receptor, NF-κB transcription factor, and EMT. Increased expression of EMT markers correlated with radiologic relapse. Docetaxel-resistant cells had increased EMT and stem-like cell markers expression. ZEB1 siRNA transfection reverted docetaxel resistance and reduced CD44 expression in DU-145R and PC-3R. Before docetaxel exposure, a selected CD44⁺ subpopulation of PC-3 cells exhibited EMT phenotype and intrinsic docetaxel resistance; ZEB1/CD44⁺ subpopulations were found in tumor cell lines and primary tumors; this correlated with aggressive clinical behavior. This study identifies genes potentially related to chemotherapy resistance and supports evidence of the EMT role in docetaxel resistance and adverse clinical behavior in early prostate cancer. Mol Cancer Ther; 13(5); 1270–84. ©2014 AACR.

PURPOSE: To determine the maximum-tolerated dose and the antitumor activity of a combination of paclitaxel, cisplatin, and gemcitabine in advanced transitional-cell carcinoma (TCC) of the urothelium. PATIENTS AND METHODS: Patients with measurable, previously untreated, locally advanced or metastatic TCC and with Eastern Cooperative Oncology Group performance status ≤ 2 and creatinine clearance ≥ 55 mL/min were eligible. Cisplatin was given on day 1 at a fixed dose of 70 mg/m². Paclitaxel and gemcitabine were given on days 1 and 8 at increasing dose levels. Cycles were repeated every 21 days to a maximum of six cycles. RESULTS: Sixty-one patients were registered. In phase I, 15 patients were entered at four different dose levels. Dose-limiting toxicity consisted of early onset (after the first cycle) grade 2 asthenia (two of six patients) and grade 3 asthenia (one of six patients) at dose level 4. A paclitaxel dose of 80 mg/m² and gemcitabine 1,000 mg/m² was recommended for phase II, and 46 additional patients were entered at this level for a total of 49 patients. Main nonhematologic toxicity was grade 2 asthenia in 18 patients, with early onset in five patients, and grade 3 in four patients. Grade 3/4 neutropenia and thrombocytopenia occurred in 27 (55%) and 11 (22%) patients, respectively. Overall, febrile neutropenia was seen in 11 patients, and one toxic death occurred because of neutropenic sepsis. The combination was active at all dose levels. In total, 58 of 61 eligible patients were assessable for response; 16 complete responses (27.6%) and 29 partial responses (50%) were observed for an overall response rate of 77.6% (95% confidence interval, 60% to 98%). The median survival time (MST) available for the phase I part of the study is 24.0 months. MST has not been reached for the whole group with the current follow-up. CONCLUSION: This combination of paclitaxel, cisplatin, and gemcitabine is feasible and highly active in patients with advanced TCC of the urothelium. Further evaluation of this regimen in patients with TCC is warranted.