The long-term survival outcome of sporadic bilateral renal cell carcinoma and optimization of surgical treatment: a large-scale population-based cohort study.

Sporadic bilateral renal cell carcinoma (BRCC) is a rare situation of RCC. The treatment for BRCC is controversial and there is a lack of authoritative guidelines about the management of BRCC. Patients diagnosed with sporadic BRCC between 2004 and 2020 were identified from Surveillance, Epidemiology, and End Results (SEER) database. The primary outcome was overall survival (OS). Kaplan-Meier survival analysis, Cox regression analysis, and competing risk regression models were used to compare survival outcomes and identify prognostic factors. A total of 20,523 patients (16,534 unilateral RCC [URCC] patients and 3989 BRCC patients) were included. The prognosis of BRCC patients is between metastatic and non-metastatic URCC patients. 3677 patients were diagnosed with localized BRCC (2180 synchronous BRCC patients and 1497 metachronous BRCC patients). Compared with metachronous BRCC, synchronous BRCC patients had relatively poor OS. However, the CSS was similar. Partial nephrectomy (PN) leads to the best OS and provides equivalent oncological outcomes to radical nephrectomy. Local tumor destruction (LTD) could also achieve an acceptable cancer-control effect. Then we developed treatment flowchart for localized BRCC patients. Additionally, we identified the prognostic factors, and analyzed the association between factors using the multivariable Cox regression method. PN should be the initial treatment for sporadic localized BRCC patients if feasible. LTD could be considered as an effective treatment alternative. This study could provide evidence for the optimization of individualized treatment for sporadic BRCC patients.Trial registration: The trial was registered on the ClinicalTrials.gov (NCT06369519).