SUO 2017: High Competing Risks Minimize Real-world Utility Of Adjuvant Targeted Therapy In Renal Cell Carcinoma: A Population-based Analysis

Washington, DC ( Introduction: Targeted therapy (TT) for renal cell carcinoma (RCC) is well established in the setting of metastatic RCC. Randomized controlled trials (RCTs) evaluating its role in the adjuvant setting for locoregional RCC have been inconclusive. The authors utilize a population-based approach to address the role of adjuvant TT in the management of RCC.

Methods: All patients with RCC from 2006 to 2013 in the SEER database were stratified by metastatic disease at the time of diagnosis (cM0 / cM1). cM0 patients following surgical excision were stratified into low and high-risk (according to the ASSURE and S-TRAC criteria). Multivariable analyses were performed to identify predictors of TT receipt; Fine and Gray competing risks analyses were used to identify predictors of cancer-specific mortality (CSM). Subset analyses included patients with clear cell histology and high-risk cM0. Finally, survival analyses were used to evaluate overall survival (OS) and cancer-specific survival (CSS) for all cohorts,
stratified on TT receipt.

Results: Based on above criteria, a total of 79,926 patients were included (71,682 cM0, 8,244 cM1) in the final analyses. The median follow-up for the entire cohort was 40.1 months. Of 31,453 patients with histologic grade data, 18,328 and 13,125 were low- and high-risk cM0, respectively. TT utilization in cM1 patients peaked at 50.6% and was associated with reduced CSM (HR 0.73, p<0.01). In contrast, TT utilization (presumed salvage therapy) never exceeded 2.2% in the entire cM0 cohort and 3.5% in the high-risk cM0 cohort. On competing risks analysis, TT receipt was associated with increased CSM in all cohorts, including subset analyses. Kaplan-Meier survival analyses demonstrated that other-cause mortality exceeds cancer-specific mortality in the cM0 population.

Conclusion: When compared to the cM1 patients, TT receipt in cM0 patients does not provide any cancer-specific survival advantage, even in the small percentage of patients that eventually progress to metastatic disease. Competing risks mortality further limit any potential benefit in this population. Similar to previous prospective studies, this large population based study demonstrates that adjuvant TT cannot be recommended for patients with RCC.

Presented by: Thenappan Chandrasekar, Toronto, Canada

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, @GoldbergHanan, at the 18th Annual Meeting of the Society of Urologic Oncology, November 29-December 1, 2017 – Washington, DC