Immunogenomic analyses associate immunological alterations with mismatch repair defects in prostate cancer.

BACKGROUND: Understanding the integrated immunogenomic landscape of advanced prostate cancer (APC) could impact stratified treatment selection. METHODS: Defective mismatch repair (dMMR) status was determined by either loss of mismatch repair protein expression on IHC or microsatellite instability (MSI) by PCR in 127 APC biopsies from 124 patients (Royal Marsden [RMH] cohort); MSI by targeted panel next-generation sequencing (MSINGS) was then evaluated in the same cohort and in 254 APC samples from the Stand Up To Cancer/Prostate Cancer Foundation (SU2C/PCF). Whole exome sequencing (WES) data from this latter cohort were analyzed for pathogenic MMR gene variants, mutational load, and mutational signatures. Transcriptomic data, available for 168 samples, was also performed. RESULTS: Overall, 8.1% of patients in the RMH cohort had some evidence of dMMR, which associated with decreased overall survival. Higher MSINGS scores associated with dMMR, and these APCs were enriched for higher T cell infiltration and PD-L1 protein expression. Exome MSINGS scores strongly correlated with targeted panel MSINGS scores (r = 0.73, P < 0.0001), and higher MSINGS scores associated with dMMR mutational signatures in APC exomes. dMMR mutational signatures also associated with MMR gene mutations and increased immune cell, immune checkpoint, and T cell-associated transcripts. APC with dMMR mutational signatures overexpressed a variety of immune transcripts, including CD200R1, BTLA, PD-L1, PD-L2, ADORA2A, PIK3CG, and TIGIT. CONCLUSION: These data could impact immune target selection, combination therapeutic strategy selection, and selection of predictive biomarkers for immunotherapy in APC. FUNDING: We acknowledge funding support from Movember, Prostate Cancer UK, The Prostate Cancer Foundation, SU2C, and Cancer Research UK.

Nomogram to Assess the Survival Benefit of New Salvage Agents for Metastatic Urothelial Carcinoma in the Era of Immunotherapy.

INTRODUCTION: Optimal end points in phase 2 trials evaluating salvage therapy for metastatic urothelial carcinoma are necessary to identify promising drugs, particularly immunotherapeutics, where response and progression-free survival may be unreliable. We developed a nomogram using data from phase 2 trials of historical agents to estimate the 12-month overall survival (OS) for patients to which observed survival of nonrandomized data sets receiving immunotherapies could be compared. PATIENTS AND METHODS: Survival and data for major prognostic factors were obtained from phase 2 trials: hemoglobin, performance status, liver metastasis, treatment-free interval, and albumin. A nomogram was developed to estimate 12-month OS. Patients were randomly allotted to discovery:validation data sets in a 2:1 ratio. Calibration plots were constructed in the validation data set and data bootstrapped to assess performance. The nomogram was tested on external nonrandomized cohorts of patients receiving pemetrexed and atezolizumab. RESULTS: Data were available from 340 patients receiving sunitinib, everolimus, docetaxel + vandetanib, docetaxel + placebo, pazopanib, paclitaxel, or docetaxel. Calibration and prognostic ability were acceptable (c index = 0.634; 95% confidence interval [CI], 0.596-0.652). Observed 12-month survival for patients receiving pemetrexed (n = 127, 23.5%; 95% CI, 16.2-31.7) was similar to nomogram-predicted survival (19%; 95% CI, 16.5-21.5; P > .05), while observed results with atezolizumab (n = 403, 39.0%; 95% CI, 34.1-43.9) exceeded predicted results (24.6%; 95% CI, 23.4-25.8; P < .001). CONCLUSION: This nomogram may be a useful tool to interpret results of nonrandomized phase 2 trials of salvage therapy for metastatic urothelial carcinoma by assessing the OS contributions of drug intervention independent of prognostic variables.

Exome Sequencing of African-American Prostate Cancer Reveals Loss-of-Function ERF Mutations.

African-American men have the highest incidence of and mortality from prostate cancer. Whether a biological basis exists for this disparity remains unclear. Exome sequencing (n = 102) and targeted validation (n = 90) of localized primary hormone-naïve prostate cancer in African-American men identified several gene mutations not previously observed in this context, including recurrent loss-of-function mutations in ERF, an ETS transcriptional repressor, in 5% of cases. Analysis of existing prostate cancer cohorts revealed ERF deletions in 3% of primary prostate cancers and mutations or deletions in ERF in 3% to 5% of lethal castration-resistant prostate cancers. Knockdown of ERF confers increased anchorage-independent growth and generates a gene expression signature associated with oncogenic ETS activation and androgen signaling. Together, these results suggest that ERF is a prostate cancer tumor-suppressor gene. More generally, our findings support the application of systematic cancer genomic characterization in settings of broader ancestral diversity to enhance discovery and, eventually, therapeutic applications.Significance: Systematic genomic sequencing of prostate cancer in African-American men revealed new insights into prostate cancer, including the identification of ERF as a prostate cancer gene; somatic copy-number alteration differences; and uncommon PIK3CA and PTEN alterations. This study highlights the importance of inclusion of underrepresented minorities in cancer sequencing studies. Cancer Discov; 7(9); 973-83. ©2017 AACR.This article is highlighted in the In This Issue feature, p. 920.

DNA Damage Response and Repair Gene Alterations Are Associated with Improved Survival in Patients with Platinum-Treated Advanced Urothelial Carcinoma.

Purpose: Platinum-based chemotherapy remains the standard treatment for advanced urothelial carcinoma by inducing DNA damage. We hypothesize that somatic alterations in DNA damage response and repair (DDR) genes are associated with improved sensitivity to platinum-based chemotherapy.Experimental Design: Patients with diagnosis of locally advanced and metastatic urothelial carcinoma treated with platinum-based chemotherapy who had exon sequencing with the Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) assay were identified. Patients were dichotomized based on the presence/absence of alterations in a panel of 34 DDR genes. DDR alteration status was correlated with clinical outcomes and disease features.Results: One hundred patients were identified, of which 47 harbored alterations in DDR genes. Patients with DDR alterations had improved progression-free survival (9.3 vs. 6.0 months, log-rank P = 0.007) and overall survival (23.7 vs. 13.0 months, log-rank P = 0.006). DDR alterations were also associated with higher number mutations and copy-number alterations. A trend toward positive correlation between DDR status and nodal metastases and inverse correlation with visceral metastases were observed. Different DDR pathways also suggested variable impact on clinical outcomes.Conclusions: Somatic DDR alteration is associated with improved clinical outcomes in platinum-treated patients with advanced urothelial carcinoma. Once validated, it can improve patient selection for clinical practice and future study enrollment. Clin Cancer Res; 23(14); 3610-8. ©2017 AACR.

Outcomes in patients with advanced urothelial carcinoma after discontinuation of programmed death (PD)-1 or PD ligand 1 inhibitor therapy.

OBJECTIVE: To study the subsequent therapy and disease outcomes of patients with advanced urothelial carcinoma (UC) after discontinuation of programmed death-1 (PD-1) or programmed death ligand 1 (PD-L1) inhibitors. PATIENTS AND METHODS: We performed a retrospective analysis to examine outcomes and systemic therapy administration after PD-1/PD-L1 inhibitor therapy in patients with advanced UC. Data on demographics and therapy administered were collected from the institutions involved in the study. Univariable Cox regression analyses were performed to examine the clinical factors potentially associated with overall survival (OS) after PD-1/PD-L1 inhibitor therapy. RESULTS: Data from 62 patients were available from four institutions, with capture of subsequent therapy and outcomes after checkpoint inhibitor immunotherapy. The median patient age was 65.5 years and 51 patients (82.3%) were male. The median (range) duration of PD-1/PD-L1 inhibitor therapy in 55 patients for whom these data were available was 64 (7-669) days. Of these, 22 patients (35.5%) received post-PD-1/PD-L1 inhibitor therapy through a variety of different chemotherapy regimens (n = 16), chemobiological combination (n = 1), biological agents (n = 4) and immunotherapy (n = 1). The median (range) time from last PD-1/PD-L1 inhibitor therapy to subsequent therapy was 58 (14-242) days. The median OS of all patients after completion of PD-1/PD-L1 inhibitor therapy was 149 days (95% confidence interval [CI]: 75-359). Among those who received some post-PD-1/PD-L1 inhibitor therapy, the median OS was 182 days (95% CI: 121-372), and the median time to progression was 124 days (95% CI: 61-273) from the start of post-PD-1/PD-L1 therapy. Among these 22 patients, the only significant baseline prognostic factor associated with OS was performance status. CONCLUSIONS: In this dataset, 35.5% of patients with advanced UC received systemic therapy after salvage therapy with PD-1/PD-L1 inhibitors. Outcomes after subsequent therapy appear similar to those historically observed in patients who had not received prior PD-1/PD-L1 inhibitor therapy. Further study of patients receiving post-PD-1/PD-L1 inhibitor therapy is warranted to identify factors associated with outcomes and potentially synergistic sequences.

Cancer immunotherapy: new applications in urologic oncology.

PURPOSE OF REVIEW: Immunotherapy in urological cancer has made substantial progress during the last 20 years, but recent advances in immunotherapy have completely transformed the present treatment landscape. In this review, we summarize major clinical achievements of immunotherapy in genitourinary cancers, as well as address potential new directions for these therapies, including new agents, combinations, and biomarkers. RECENT FINDINGS: Recently, nivolumab and atezolizumab have joined sipuleucel-T as Food and Drug Administration-approved therapies in urological malignancies. Additional checkpoint inhibitors and vaccines are being tested in clinical trials. Furthermore, significant work has been done exploring predictors of response to therapy. SUMMARY: Immunotherapy has changed the treatment of urologic malignancies. New immunotherapies and novel combinations will continue to create new treatment options in urologic tumors.

Correlation of Apobec Mrna Expression with overall Survival and pd-l1 Expression in Urothelial Carcinoma.

Metastatic urothelial carcinoma (mUC) has a very high mutational rate and is associated with an APOBEC mutation signature. We examined the correlation of APOBEC expression with overall survival (OS) and PD-L1 expression in a cohort of 73 mUC patients. mRNA expression of APOBEC3 family of genes (A3A, A3B, A3C, A3F_a, A3F_b, A3G, A3H) was measured using Nanostring. PD-L1 expression, evaluated by immunohistochemistry, on tumor infiltrating mononuclear cells (TIMCs) and tumor cells was scored from 0 to 4, with 2-4 being positive. Wilcoxon's non-parametric tests assessed the association of APOBEC and PD-L1. The Cox regression model assessed the association of APOBEC with OS. All APOBEC genes were expressed in mUC. Increased A3A, A3D, and A3H expression associates with PD-L1 positive TIMCs (p = 0.0009, 0.009, 0.06). Decreased A3B expression was marginally associated with PD-L1 positive TIMCs expression (p = 0.05). Increased A3F_a and A3F_b expression was associated with increased expression of PD-L1 on tumor cells (p = 0.05). Increased expression of A3D and A3H was associated with longer OS (p = 0.0009). Specific APOBEC genes have different effects on mUC in terms of survival and PD-L1 expression. A3D and A3H may have the most important role in mUC as they are associated with OS and PD-L1 TIMC expression.

Association of tumour microRNA profiling with outcomes in patients with advanced urothelial carcinoma receiving first-line platinum-based chemotherapy.

BACKGROUND: Tumour expression of selected microRNAs (miRs) correlates with cisplatin efficacy in multiple cancers. We investigated the role of selected miRs in patients receiving cisplatin-based therapy for advanced urothelial carcinoma (UC). METHODS: RNA was extracted from formalin-fixed paraffin-embedded tumour from 83 advanced UC patients who received cisplatin. A miR panel based on relevance for platinum sensitivity and UC was studied by quantitative reverse transcription quantitative PCR (RT-qPCR). Association of progression-free survival (PFS) with miR expression was analysed using cox regression. Selected TFs were chosen by association with the panel of miRs using the Transcription Regulation algorithm (GeneGo MetaCore+MetaDrug version 6.23 build 67496). Bladder cancer (BC) cell lines were used to investigate the previously described role of miR-21 mediating cisplatin sensitivity. RESULTS: The 83 patients had a median PFS of 8 months. In multivariate analysis, higher levels of E2F1 (P=0.01, HR: 1.95 (1.14, 3.33)), miR-21 (P=0.01, HR: 2.01 (1.17, 3.45)) and miR-372 (P=0.05, HR: 1.70 (1.00, 2.89)) were associated with a shorter PFS. In the 8 BC cell lines, miR-21 was not shown to be necessary nor sufficient for modulating cisplatin sensitivity. CONCLUSIONS: In metastatic UC patients treated with cisplatin-based therapy, high primary tumour levels of E2F1, miR-21 and miR-372 are associated with poor PFS independent of clinical prognostic factors. The in vitro study could not confirm miR-21 levels role in modulating platinum sensitivity.

Chromatin immunoprecipitation from fixed clinical tissues reveals tumor-specific enhancer profiles.

Extensive cross-linking introduced during routine tissue fixation of clinical pathology specimens severely hampers chromatin immunoprecipitation followed by next-generation sequencing (ChIP-seq) analysis from archived tissue samples. This limits the ability to study the epigenomes of valuable, clinically annotated tissue resources. Here we describe fixed-tissue chromatin immunoprecipitation sequencing (FiT-seq), a method that enables reliable extraction of soluble chromatin from formalin-fixed paraffin-embedded (FFPE) tissue samples for accurate detection of histone marks. We demonstrate that FiT-seq data from FFPE specimens are concordant with ChIP-seq data from fresh-frozen samples of the same tumors. By using multiple histone marks, we generate chromatin-state maps and identify cis-regulatory elements in clinical samples from various tumor types that can readily allow us to distinguish between cancers by the tissue of origin. Tumor-specific enhancers and superenhancers that are elucidated by FiT-seq analysis correlate with known oncogenic drivers in different tissues and can assist in the understanding of how chromatin states affect gene regulation.

Precision medicine for advanced prostate cancer.

PURPOSE OF REVIEW: Precision cancer medicine, the use of genomic profiling of patient tumors at the point-of-care to inform treatment decisions, is rapidly changing treatment strategies across cancer types. Precision medicine for advanced prostate cancer may identify new treatment strategies and change clinical practice. In this review, we discuss the potential and challenges of precision medicine in advanced prostate cancer. RECENT FINDINGS: Although primary prostate cancers do not harbor highly recurrent targetable genomic alterations, recent reports on the genomics of metastatic castration-resistant prostate cancer has shown multiple targetable alterations in castration-resistant prostate cancer metastatic biopsies. Therapeutic implications include targeting prevalent DNA repair pathway alterations with PARP-1 inhibition in genomically defined subsets of patients, among other genomically stratified targets. In addition, multiple recent efforts have demonstrated the promise of liquid tumor profiling (e.g., profiling circulating tumor cells or cell-free tumor DNA) and highlighted the necessary steps to scale these approaches in prostate cancer. SUMMARY: Although still in the initial phase of precision medicine for prostate cancer, there is extraordinary potential for clinical impact. Efforts to overcome current scientific and clinical barriers will enable widespread use of precision medicine approaches for advanced prostate cancer patients.

Expression Levels of DNA Damage Repair Proteins Are Associated With Overall Survival in Platinum-Treated Advanced Urothelial Carcinoma.

BACKGROUND: Combination platinum chemotherapy is standard first-line therapy for metastatic urothelial carcinoma (mUC). Defining the platinum response biomarkers for patients with mUC could establish personalize medicine and provide insights into mUC biology. Although DNA repair mechanisms have been hypothesized to mediate the platinum response, we sought to analyze whether increased expression of DNA damage genes would correlate with worse overall survival (OS) in patients with mUC. PATIENTS AND METHODS: We retrospectively identified a clinically annotated cohort of patients with mUC, who had been treated with first-line platinum combination chemotherapy. A tissue microarray was constructed from formalin-fixed paraffin-embedded tissue from the primary tumor before treatment. Immunohistochemical analysis of the following DNA repair proteins was performed: ERCC1, RAD51, BRCA1/2, PAR, and PARP-1. Nuclear and cytoplasmic expression was analyzed using multispectral imaging. Nuclear staining was used for the survival analysis. Cox regression analysis was used to evaluate the associations between the percentage of positive nuclear staining and OS in multivariable analysis, controlling for known prognostic variables. RESULTS: In a cohort of 104 patients with mUC, a greater percentage of nuclear staining of ERCC1 (hazard ratio [HR], 2.7; 95% confidence interval [CI], 1.5-4.9; P = .0007), RAD51 (HR, 5.6; 95% CI, 1.7-18.3; P = .005), and PAR (HR, 2.2; 95% CI, 1.1-4.4; P = .026) was associated with worse OS. BRCA1, BRCA2, and PARP-1 expression was not associated with OS (P = .76, P = .38, and P = .09, respectively). A greater percentage of combined ERCC1 and RAD51 nuclear staining was strongly associated with worse OS (P = .005). CONCLUSION: A high percentage of nuclear staining of ERCC1, RAD51, and PAR, assessed by immunohistochemistry, correlated with worse OS for patients with mUC treated with first-line platinum combination chemotherapy, supporting the evidence of the DNA repair pathways' role in the prognosis of mUC. We also report new evidence that RAD51 and PAR might play a role in the platinum response. Additional prospective studies are required to determine the prognostic or predictive nature of these biomarkers in mUC.

Single-agent Taxane Versus Taxane-containing Combination Chemotherapy as Salvage Therapy for Advanced Urothelial Carcinoma.

BACKGROUND: Single-agent taxanes are commonly used as salvage systemic therapy for patients with advanced urothelial carcinoma (UC). OBJECTIVE: To study the impact of combination chemotherapy delivering a taxane plus other chemotherapeutic agents compared with single-agent taxane as salvage therapy. DESIGN, SETTING, AND PARTICIPANTS: Individual patient-level data from phase 2 trials of salvage systemic therapy were used. INTERVENTIONS: Trials evaluating either single agents (paclitaxel or docetaxel) or combination chemotherapy (taxane plus one other chemotherapeutic agent or more) following prior platinum-based therapy were used. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Information regarding the known major baseline prognostic factors was required: time from prior chemotherapy, hemoglobin, performance status, albumin, and liver metastasis status. Cox proportional hazards regression was used to evaluate the association of prognostic factors and combination versus single-agent chemotherapy with overall survival (OS). RESULTS AND LIMITATIONS: Data were available from eight trials including 370 patients; two trials (n=109) evaluated single-agent chemotherapy with docetaxel (n=72) and cremophor-free paclitaxel (n=37), and six trials (n=261) evaluated combination chemotherapy with gemcitabine-paclitaxel (two trials, with n=99 and n=24), paclitaxel-cyclophosphamide (n=32), paclitaxel-ifosfamide-nedaplatin (n=45), docetaxel-ifosfamide-cisplatin (n=26), and paclitaxel-epirubicin (n=35). On multivariable analysis after adjustment for baseline prognostic factors, combination chemotherapy was independently and significantly associated with improved OS (hazard ratio: 0.60; 95% confidence interval, 0.45-0.82; p=0.001). The retrospective design of this analysis and the trial-eligible population were inherent limitations. CONCLUSIONS: Patients enrolled in trials of combination chemotherapy exhibited improved OS compared with patients enrolled in trials of single-agent chemotherapy as salvage therapy for advanced UC. Prospective randomized trials are required to validate a potential role for rational and tolerable combination chemotherapeutic regimens for the salvage therapy of advanced UC. PATIENT SUMMARY: This retrospective study suggests that a combination of chemotherapy agents may extend survival compared with single-agent chemotherapy in selected patients with metastatic urothelial cancer progressing after prior chemotherapy.

Temporal trends in receipt of adequate lymphadenectomy in bladder cancer 1988 to 2010.

INTRODUCTION AND OBJECTIVE: The importance of pelvic lymphadenectomy (LND) for diagnostic and therapeutic purposes at the time of radical cystectomy (RC) for bladder cancer is well documented. Although some debate remains on the optimal number of lymph nodes removed, 10 nodes has been proposed as constituting an adequate LND. We used data from the Surveillance, Epidemiology, and End Results database to examine predictors and temporal trends in the receipt of an adequate LND at the time of RC for bladder cancer. MATERIAL AND METHODS: Within the Surveillance, Epidemiology, and End Results database, we extracted data on all patients with nonmetastatic bladder cancer receiving RC in the years 1988 to 2010. First, we assess the proportion of individuals undergoing RC who received an adequate LND (≥10 nodes removed) over time. Second, we calculate odds ratios (ORs) of receiving an adequate LND using logistic regression modeling to compare study periods. Covariates included sex, race, age, region, tumor stage, urban vs. rural location, and insurance status. RESULTS: Among the 5,696 individuals receiving RC during the years 1988 to 2010, 2,576 (45.2%) received an adequate LND. Over the study period, the proportion of individuals receiving an adequate LND increased from 26.4% to 61.3%. The odds of receiving an adequate LND increased over the study period; a patient undergoing RC in 2008 to 2010 was over 4-fold more likely to receive an adequate LND relative to a patient treated in 1988 to 1991 (OR = 4.63, 95% CI: 3.32-6.45). In addition to time of surgery, tumor stage had a positive association with receipt of adequate LND (OR = 1.49 for stage IV [T4 N1 or N0] vs. stage I [T1 or Tis], 95% CI: 1.22-1.82). Age, sex, marital status, and race were not significant predictors of adequate LND. CONCLUSION: Adequacy of pelvic LND remains an important measure of surgical quality in bladder cancer. Our data show that over the years 1988 to 2010, the likelihood of receiving an adequate LND has increased substantially; however, a substantial minority of patients still does not receive LND. Further study into factors leading to adequate LND is needed to increase the use of this important technique.

Somatic Copy Number Abnormalities and Mutations in PI3K/AKT/mTOR Pathway Have Prognostic Significance for Overall Survival in Platinum Treated Locally Advanced or Metastatic Urothelial Tumors.

BACKGROUND: An integrative analysis was conducted to identify genomic alterations at a pathway level that could predict overall survival (OS) in patients with advanced urothelial carcinoma (UC) treated with platinum-based chemotherapy. PATIENTS AND METHODS: DNA and RNA were extracted from 103 formalin-fixed paraffin embedded (FFPE) invasive high-grade UC samples and were screened for mutations, copy number variation (CNV) and gene expression analysis. Clinical data were available from 85 cases. Mutations were analyzed by mass-spectrometry based on genotyping platform (Oncomap 3) and genomic imbalances were detected by comparative genomic hybridization (CGH) analysis. Regions with threshold of log2 ratio ≥0.4, or ≤0.6 were defined as either having copy number gain or loss and significantly recurrent CNV across the set of samples were determined using a GISTIC analysis. Expression analysis on selected relevant UC genes was conducted using Nanostring. To define the co-occurrence pattern of mutations and CNV, we grouped genomic events into 5 core signal transduction pathways: 1) TP53 pathway, 2) RTK/RAS/RAF pathway, 3) PI3K/AKT/mTOR pathway, 4) WNT/CTNNB1, 5) RB1 pathway. Cox regression was used to assess pathways abnormalities with survival outcomes. RESULTS: 35 samples (41%) harbored mutations on at least one gene: TP53 (16%), PIK3CA (9%), FGFR3 (2%), HRAS/KRAS (5%), and CTNNB1 (1%). 66% of patients had some sort of CNV. PIK3CA/AKT/mTOR pathway alteration (mutations+CNV) had the greatest impact on OS (p=0.055). At a gene level, overexpression of CTNNB1 (p=0.0008) and PIK3CA (p=0.02) were associated with shorter OS. Mutational status on PIK3CA was not associated with survival. Among other individually found genomic alterations, TP53 mutations (p=0.07), mTOR gain (p=0.07) and PTEN overexpression (p=0.08) have a marginally significant negative impact on OS. CONCLUSIONS: Our study suggests that targeted therapies focusing on the PIK3CA/AKT/mTOR pathway genomic alterations can generate the greatest impact in the overall patient population of high-grade advanced UC.

Perioperative therapy for muscle invasive bladder cancer.

Muscle invasive bladder cancer (MIBC) is an aggressive disease associated with poor survival rates. High rates of relapse, despite radical cystectomy, suggest that administration of systemic therapy in the perioperative period may improve clinical outcomes. Neoadjuvant treatment with cisplatin-based combination regimens is an established standard of care and has improved long-term survival in MIBC. As the use of neoadjuvant chemotherapy steadily increases, clinicians still need to decide about administering adjuvant chemotherapy to patients with high-risk disease. This review examines in detail the latest evidence available for both neoadjuvant and adjuvant chemotherapy, and highlights pertinent studies.

HER2 as a target in invasive urothelial carcinoma.

We evaluated primary tumors from two cohorts, Spain (N = 111) and Greece (N = 102), for patients who were treated with platinum-based chemotherapy. Patients were tested for HER2 status (IHC score of 3+ or FISH ratio of ≥ 2.2) by immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), DNA copy number, mRNA expression, and mutation status in patients with metastatic urothelial carcinoma (UC), and its impact on survival. ERBB2 mutation was determined by hotspot sequencing. mRNA expression was assessed using NanoString counting. Association of overall survival (OS) and HER2 status was assessed by a Cox regression model. NIH-3T3 cells containing HER2 V777L were assessed for growth, invasion, and HER2 kinase activation. In all, 22% of Spanish and 4% of Greek cohorts had 3+ HER2 staining by IHC. FISH amplification was identified in 20% of Spanish and 4% of Greek cohorts. Kappa coefficient between FISH and IHC was 0.47. HER2 status was not associated with OS in univariate (Spanish P = 0.34; Greek P = 0.11) or multivariate (Spanish P = 0.49; Greek P = 0.12) analysis. HER2-positive tumors expressed higher levels of HER2 mRNA than HER2-negative tumors (P < 0.001). HER2 mutations (V777L and L755S) were identified in two (2%) patients. In vitro analysis of V777L results in transformation of NIH-3T3 cells, leading to increased growth, invasion on soft agar, and HER2 kinase constitutive activation. In summary, HER2 overexpression or amplification in the primary tumor did not predict OS in patients with metastatic UC. HER2 positivity rates can differ between different populations. Further trials in genomically screened patients are needed to assess HER2-targeted therapies in UC.

Incomplete Cross-Resistance Between Taxanes for Advanced Urothelial Carcinoma: Implications for Clinical Practice and Trial Design.

BACKGROUND: Taxanes such as paclitaxel and docetaxel are commonly used for second- or third-line salvage systemic therapy for metastatic UC. Although trials have generally excluded previous exposure to taxanes when using a taxane in a salvage therapy trial, taxanes might not be completely cross-resistant. Hence, we aimed to study outcomes with docetaxel after previous paclitaxel and the reverse sequence, to identify the level of cross-resistance between these taxanes. PATIENTS AND METHODS: Data from a randomized phase II trial that compared salvage therapy with docetaxel combined with either placebo or vandetanib for advanced UC were analyzed. Both arms were combined for analysis because no differences in any outcomes were observed. Data were also requested from institutions for patients who received paclitaxel after previous docetaxel treatment. Descriptive statistics were used to summarize patient and treatment characteristics and outcomes. The primary clinical end point of interest was overall survival (OS). RESULTS: Of 148 patients who received docetaxel with either vandetanib or placebo, 21 had received previous paclitaxel treatment. No difference in OS, progression-free survival, or response rate was observed with docetaxel based on previous paclitaxel treatment after adjusting for known prognostic factors. Among the 8 patients who received paclitaxel after previous docetaxel treatment, partial response was observed in 1 patient (12.5%) and stable disease in 2 patients (25%). CONCLUSION: Docetaxel treatment after previous paclitaxel treatment and the reverse sequence demonstrates activity in advanced UC. There is no strong evidence to disallow patients with previous exposure to a taxane to enroll in a clinical trial involving another taxane.