Prognosis and clinicopathological characteristics of renal cell carcinoma: does bilateral occurrence influence overall and cancer-specific survival?

BACKGROUND: To compare clinicopathological characteristics and prognosis of bilateral and unilateral renal cell carcinoma. METHODS: Data from patients who had been diagnosed with renal cell carcinoma (RCC) and undergone radical nephrectomy (RN) from 2004 to 2014 were extracted from the Surveillance, Epidemiology, and End Results (SEER) registry. The χ(2) test was used to compare relevant characteristics between patients with bilateral and unilateral RCC. Survival curves were generated by the Kaplan-Meier method and the log-rank test was used to compare overall survival (OS) and cancer-specific survival (CSS). Cox proportional hazards regression analysis was used to determine the risk factors for OS and CSS. RESULTS: The study cohort comprised 41,573 patients. A nonlinear relationship between age and OS and CSS was identified with and without adjusting for potential factors. Threshold effect analysis revealed that ages 54 and age 74 were the turning points associated with changes in OS and CSS, respectively. Multivariate Cox regression analysis demonstrated that age category, race, grade, and T, N, and M stage were prognostic factors for OS and CSS of patients with RCC. Additionally, sex and pathology were significantly associated with OS. CONCLUSIONS: Bilateral occurrence does not influence OS and CSS in patients with RCC who have undergone RN. The risk of poor OS and CSS was higher with greater age category, tumor grade, and T stage. Patients in different age categories (<54, ≥54 and <74, ≥74 years) may benefit from individualized attention and therapeutic strategies.