Clinical correlates and prognostic value of different metastatic sites in metastatic renal cell carcinoma.

Aim: Real life data on the clinical correlates and prognostic value of metastatic sites in metastatic renal cell carcinoma (RCC) are needed. This parameter was assessed in RCC patients registered within the surveillance, epidemiology and end results (SEER) database. Methods: Data were obtained from the National Cancer Institute-SEER database spanning 2010-2013; and it has been accessed through SEER*Stat program to determine the clinical correlates and prognosis of RCC patients with distant metastases according to the site of metastasis. Multivariate analyses were performed using Cox regression analysis to determine factors associated with improved overall and cancer-specific survival. Kaplan-Meier curves and log-rank tests were used to calculate and compare survival estimates. Results: A total of 5992 patients with metastatic RCC were identified in the period from 2010 to 2013. Patients with isolated liver metastases have worse survival outcomes compared with patients with other single organ sites of metastases. Pairwise p-values for cancer-specific survival: bone metastasis versus liver metastasis: p < 0.0001; lung metastasis versus liver metastasis: p = 0.002; distant lymph nodes versus liver metastasis: p = 0.006. Multivariate analysis revealed that younger age at diagnosis (p < 0.0001), single organ site of metastatic disease (p = 0.046), male gender (p = 0.001), earlier T stage (p < 0.0001), node negative status (p < 0.0001), clear cell histology (p = 0.001), local treatment to the primary tumor (p < 0.0001) and surgery to the metastatic disease (p < 0.0001) were associated with better overall survival. The same factors (except age) were associated with better cancer-specific survival. Conclusion: Metastatic RCC patients with liver metastases seem to have worse outcomes compared with patients with other sites of metastases.