Trends in Metastatic Kidney Cancer Survival From the Cytokine to the Targeted Therapy Era

Abstract

Objective: To evaluate population-based survival trends, compared to optimistic trial benchmarks, in metastatic renal cell carcinoma (mRCC). Advances in medical therapy for mRCC may be associated with survival improvements. Yet, targeted therapy trial results focus on patients with favorable-risk mRCC and may not be well disseminated at the population level.

Methods: Surveillance, Epidemiology, and End Results identified adult mRCC patients diagnosed between 1990 and 2009. Survival was analyzed by treatment era (cytokine, 1990-2005; targeted therapy, 2006-2009) and stratified by histology. Multivariate Cox regression identified factors independently associated with overall survival.

Results: We identified 14,521 eligible patients. For clear cell mRCC (N = 4149), median survival improved from 11 to 14 months before and after targeted therapy (P <.001). For RCC with sarcomatoid features (N = 608) and RCC not otherwise specified (N = 8860), survival did not change (median survival 4 months for both). For non-clear cell subtypes (N = 904), median survival improved from 7 to 9 months (P = .008). On multivariate analysis, factors associated with increased overall survival were as follows: treatment in the targeted era (hazard ratio [HR], 0.87; 95% confidence interval [CI], 0.84-0.91), clear cell histology (HR, 0.76; 95% CI, 0.73-0.80), and receipt of surgery (HR, 0.43; 95% CI, 0.41-0.46).

Conclusion: Population-based mRCC median survival improved but to a lesser degree than that reported in clinical trials. This represents opportunity for quality improvement in histologically guided care, use of cytoreductive nephrectomy, and development of strategies for trial-ineligible, poor-risk patients.