The impact of histology on survival for patients with metastatic renal cell carcinoma undergoing cytoreductive nephrectomy

Objective: To evaluate the impact of histology on cancer-specific and overall survival for patients with metastatic renal cell carcinoma (mRCC) undergoing cytoreductive nephrectomy (CN). Materials and Methods: We retrospectively reviewed the data of 505 patients with mRCC who underwent CN at Mayo Clinic, Rochester, MN, USA, between 1970 and 2008. All specimen were re-reviewed by a single genitourinary pathologist. Survival was estimated using the Kaplan-Meier method and compared according to histology with the log-rank test. Cox proportional hazard regression models were used to evaluate the association of histology with outcome. Results: Forty (8%) patients with non-clear cell histology and 465 (92%) patients with clear cell histology were identified. The median follow-up was 7.8 years. Metastatic non-clear cell histology was associated with a significantly older median age at nephrectomy (66 vs. 60 years; P = 0.002), larger median tumor size (11.5 vs. 9.2 cm; P = 0.02), and higher rate of lymph node involvement (50% vs. 16%; P < 0.001). No significant difference in 3-year cancer-specific survival (25% vs. 22%; P = 0.50) was noted between patients with clear cell and non-clear cell histology. On multivariate analysis, non-clear cell histology was not significantly associated with patients' risk of death from cancer (HR 0.96; 95% CI 0.61, 1.51; P = 0.85). Conclusions: Non-clear cell histology was not independently associated with adverse survival for patients with mRCC undergoing CN. As such, we advocate that surgical resection should continue to be considered in the multimodal treatment approach to these patients, while additional efforts to risk stratify and optimize management in this setting remain necessary.