Nguyen, Paul L.

5000 Background: It is clinically challenging to integrate genomic classifier results that report a continuous numerical risk of recurrence into treatment decisions for prostate cancer (PCa). We aimed to develop a novel clinical-genomic risk system that can readily be incorporated into treatment guidelines for localized PCa. Methods: Four multi-center cohorts (n = 6928 men; 5937 prospective samples and 991 retrospective samples with long-term follow-up) were utilized to identify and validate our clinical-genomic risk system in radical prostatectomy (RP) samples and subsequently in pre-treatment biopsy samples. All patients’ FFPE tissue underwent microarray analysis, and the expression values for 22 prespecified biomarkers that constitute Decipher were extracted. Cumulative incidence curves were constructed to estimate metastasis risk. C-indices were calculated to compare NCCN and CAPRA score to our clinical-genomic system. Results: With a median follow-up of 8 years for men in our RP cohort, the 10-year distant metastasis rates for NCCN low, favorable-intermediate, unfavorable-intermediate, and high-risk were 7.8%, 9.4%, 40.1%, and 41.4%, respectively. Our 3-tier clinical-genomic risk groups had 10-year distant metastasis rates of 3.7%, 30.7%, and 57.7%, for low, intermediate, and high-risk, which were validated in our pre-treatment biopsy cohort with 10-year rate of distant metastasis of 0%, 30.3%, and 63.2%, respectively. C-indices for the clinical-genomic system (0.84, 95%CI 0.62-0.92) were significantly improved over NCCN (0.71, 95%CI 0.59-0.84) and CAPRA (0.71, 95%CI 0.60-0.81) score. A total of 33.4% of men would be reclassified by the clinical-genomic system, and specifically 17.1%, 41.3%, and 19.4% of men in NCCN low, intermediate and high risk groups would be reclassified by our new system. Conclusions: The use of a readily available genomic classifier in combination with clinicopathologic variables can generate a simple to use 3-tier clinical-genomic risk system that is highly prognostic for distant metastasis, is more accurate than clinical risk, and can be easily incorporated into NCCN guidelines to inform treatment decisions.

Purpose In April 2017, the American Urological Association, American Society for Radiation Oncology, and Society of Urologic Oncology released a joint evidence-based practice guideline on clinically localized prostate cancer. The American Society of Clinical Oncology (ASCO) has a policy and set of procedures for endorsing clinical practice guidelines that have been developed by other professional organizations. Methods The Clinically Localized Prostate Cancer guideline was reviewed for developmental rigor by methodologists. An ASCO Expert Panel then reviewed the content and the recommendations. Results The ASCO Expert Panel determined that the recommendations from the Clinically Localized Prostate Cancer guideline were clear, thorough, and based upon the most relevant scientific evidence. ASCO endorsed the Clinically Localized Prostate Cancer guideline except for two recommendations on cryosurgery. The two recommendations covering cryosurgery were not endorsed because the panel found that there is insufficient evidence to support the use of cryotherapy in this setting. Recommendations The ASCO Expert Panel endorsed all but two of the original guideline recommendations as written and offered a series of discussion points to guide practice.

Abstract Purpose: Currently, no genomic signature exists to distinguish men most likely to progress on adjuvant androgen deprivation therapy (ADT) after radical prostatectomy for high-risk prostate cancer. Here we develop and validate a gene expression signature to predict response to postoperative ADT. Experimental Design: A training set consisting of 284 radical prostatectomy patients was established after 1:1 propensity score matching metastasis between adjuvant-ADT (a-ADT)-treated and no ADT–treated groups. An ADT Response Signature (ADT-RS) was identified from neuroendocrine and AR signaling–related genes. Two independent cohorts were used to form three separate data sets for validation (set I, n = 232; set II, n = 435; set III, n = 612). The primary endpoint of the analysis was postoperative metastasis. Results: Increases in ADT-RS score were associated with a reduction in risk of metastasis only in a-ADT patients. On multivariable analysis, ADT-RS by ADT treatment interaction term remained associated with metastasis in both validation sets (set I: HR = 0.18, Pinteraction = 0.009; set II: HR = 0.25, Pinteraction = 0.019). In a matched validation set III, patients with Low ADT-RS scores had similar 10-year metastasis rates in the a-ADT and no-ADT groups (30.1% vs. 31.0%, P = 0.989). Among High ADT-RS patients, 10-year metastasis rates were significantly lower for a-ADT versus no-ADT patients (9.4% vs. 29.2%, P = 0.021). The marginal ADT-RS by ADT interaction remained significant in the matched dataset (Pinteraction = 0.035). Conclusions: Patients with High ADT-RS benefited from a-ADT. In combination with prognostic risk factors, use of ADT-RS may thus allow for identification of ADT-responsive tumors that may benefit most from early androgen blockade after radical prostatectomy. We discovered a gene signature that when present in primary prostate tumors may be useful to predict patients who may respond to early ADT after surgery. Clin Cancer Res; 24(16); 3908–16. ©2018 AACR.

3 Background: There is a clear need to develop a clinically relevant molecular subtyping approach for prostate cancer. We hypothesized that prostate cancer can be subtyped based on luminal versus basal lineage. Methods: We applied the PAM50 classifier, which is used clinically to identify luminal and basal cancers in breast cancer, to subtype a total of 3,782 prostate cancer samples using a high-density microarray platform run in a CLIA-certified laboratory. We examined the associations of these subtypes and clinical outcomes. Results: We demonstrate that PAM50 segregates prostate cancer into three reproducible subtypes in both retrospective cohorts and on prospective validation: luminal A (33.3%-34.3%), luminal B (28.5%-32.6%), and basal (34.1%-37.1%). Luminal B prostate cancers exhibited the worst clinical prognoses, followed by basal and luminal A subtypes (10-year biochemical recurrence-free survival: 29/39/41%; distant metastasis-free survival: 53/73/73%; prostate cancer-specific survival: 78/86/89%; overall survival: 69/80/82% respectively) on both univariable and multivariable analyses accounting for standard clinicopathologic prognostic factors. Known luminal lineage markers, such as NKX3.1 and KRT18, and the basal lineage CD49f signature, were enriched in luminal- and basal-like cancers respectively, demonstrating the connection between these subtypes and established prostate cancer biology. While both luminal-like subtypes were associated with increased AR expression and signaling, only luminal B prostate cancers were significantly associated with post-operative response to androgen deprivation therapy (ADT) in a subset analysis matching patients based on clinicopathologic variables (interaction p = 0.006, luminal B 10-year metastasis: 33% (treated) vs. 55% (untreated), non-luminal B: 37% (treated) vs. 21% (untreated)). Conclusions: These findings contribute novel insight into the biology of prostate cancer, and provide translatable clinical tools for personalizing post-operative ADT for patients with prostate cancer. Similar to breast cancer, these findings suggest that luminal/basal subtyping may be useful in treatment selection in prostate cancer.

334 Background: Radical cystectomy (RC) represents the standard of care for patients with muscle-invasive urothelial carcinoma of the urinary bladder (UCUB). Alternative organ-conserving treatments such as chemotherapy and/or radiotherapy have gained interest. We sought to compare survival outcomes of patients according to treatment modalities, in a stage-for-stage analysis. Methods: We relied on the Surveillance, Epidemiology, and End Results Medicare-linked database to identify 12,950 patients diagnosed with T2–T4a N0/x M0 UCUB between years 1992 and 2009. Treatment types include RC (n=5207), chemotherapy/radiation (n=2,669), and surveillance (n=5,074). Following instrumental variable analysis, Cox- and competing-risks regression analyses were performed for prediction of overall survival (OS) and cancer-specific mortality (CSM), respectively. All analyses were stratified according to disease stage (T2, T3, T4a). Results: After adjusting for potential confounders, OS was more favorable for RC relative to chemotherapy/radiation (hazard ratio [HR]: 1.57, 95% confidence interval [CI]: 1.02–2.40) or surveillance (HR: 1.82, 95% CI: 1.20–2.78) in patients with T2 UCUB. For the same stage, CSM rates were lower in the surgery group compared to chemotherapy/radiation (HR: 2.05, 95% CI: 1.14–3.67) or surveillance (HR: 1.95, 95% CI: 1.09–3.48). When analyses focused on individuals with more advanced disease (T3–T4a), no statistically significant difference was observed between chemotherapy/radiation relative to RC for both OS and CSM. Conclusions: In the current retrospective population-based cohort, RC was associated with improved survival outcomes relative to its alternative treatment counterparts. However, this effect was only observable in patients with T2 disease. Conversely, no difference between chemotherapy/radiation vs. surgery was noted in patients with more advanced disease stage.

167 Background: Physicians have a variety of resources available about the treatment of localized prostate cancer. Yet, it is largely unknown what resources and evidence radiation oncologists and urologists commonly use to inform patients and possibly alter clinical practice. In this national survey study, we assessed the types of resources prostate cancer specialists’ use and the level of evidence needed to change treatment recommendations in localized prostate cancer. Methods: From a random sample, 1,422 physicians were sent a mail survey assessing what type of information was used to guide prostate cancer treatment. The survey also queried what level of evidence could alter recommendations. Multivariable logistic regression models were used to identify for differences in physician characteristics for each outcome. Results: Survey response rates were similar for radiation oncologists and urologists (44% vs. 46%; p=0.46). Specialty-specific journals represented the most commonly used resource to inform the clinical practice for radiation oncologists (65%) and urologists (70%). Relative to radiation oncologists, urologists were less likely to utilize medical journals (25% vs. 38.7%, OR: 0.50; p=0.01), cancer journals (21.7% vs. 50.8%, OR: 0.50; p<0.001), but more likely to rely on clinical guidelines (46.3% vs. 37.7%,OR: 1.6; p=0.006). Radiation oncologists and urologists both viewed RCT’s as the most likely source of evidence needed to change treatment recommendations (85% vs. 77%). Conclusions: Both specialties most commonly rely on their specialty-specific journals to inform their clinical practice and view RCT’s as the level of evidence needed to change treatment recommendations for localized prostate cancer. Radiation oncologists embraced greater diversity in literature, while urologists were more likely to use clinical guidelines. Utilizing this information may overcome barriers to the dissemination and adoption of new treatment paradigms for localized prostate cancer.