Impact of Aspirin and Non-Aspirin Nonsteroidal Anti-Inflammatory Drugs on Outcomes in Patients with Metastatic Renal Cell Carcinoma

Background: Non-steroidal anti-inflammatory drugs (NSAIDs) have demonstrated an anti-tumorigenic effect in several cancers. However, their use is associated with an increased risk in renal cell carcinoma (RCC) and their effect has not been assessed in patients with metastatic disease. Objective: We investigated the impact of NSAIDs on survival outcomes in patients with metastatic RCC (mRCC). Methods: We conducted a pooled retrospective analysis of 4,736 mRCC patients treated on phase II and III clinical trials. Patients were categorized as: aspirin (ASA) only users, non-ASA NSAIDs only users, ASA and non-ASA NSAIDs users, and NSAIDs non-users. The primary endpoint was overall survival (OS). Progression free survival (PFS), overall response rate (ORR) and adverse events (AEs) were secondary endpoints. OS and PFS were estimated using the Kaplan–Meier method and were assessed using multivariate Cox regression analysis. Results: We identified 457 (10%) ASA only users, 639 (13%) non-ASA NSAIDs only users, 61 (1%) ASA and non-ASA NSAIDS users, and 3579 (76%) NSAIDs non-users. OS and PFS were significantly worse in non-ASA NSAIDs users compared to the NSAIDs non-users (OS hazard ratio (HR): 1.47, p < 0.0001, median 11.6 versus 21.1 months; PFS HR: 1.29, p < 0.0001, median 4.6 versus 7.4 months). There was no difference in survival in ASA users or ASA and non-ASA NSAIDs users compared to NSAIDs non-users. Conclusions: Our analysis demonstrates that NSAIDs do not confer a survival advantage in mRCC patients. Further studies are warranted to elucidate the interaction of NSAIDS with targeted therapy in mRCC.