Metachronous bilateral renal cell carcinoma: risk assessment, prognosis and relevance of the primary-free interval.

Purpose: We evaluated the prognosis, risk factors and relevance of the primary-free interval in a large cohort with metachronous bilateral renal cell carcinoma.
Materials and Methods: We studied 120 patients with metachronous, bilateral renal cell carcinoma who were treated at 12 international academic centers. Logistic regression was performed to evaluate risk factors for contralateral metachronous renal cell carcinoma during followup. Disease specific survival was evaluated with univariate and multivariate analysis.
Results: Median age at diagnosis of the first and second renal cell carcinomas was 54 and 62 years, respectively. The most common histological subtype was bilateral clear cell renal cell carcinoma (89% of cases). Familial renal cell carcinoma was found in 14% of patients, von Hippel-Lindau disease was found in 4% and nonfamilial renal cell carcinoma was found in 81%. The 15-year disease specific survival rates for the first and second renal cell carcinomas were 66% and 44%, respectively. Logistic regression revealed von Hippel-Lindau disease, a family history of renal cell carcinoma, multifocal first renal cell carcinoma and young patient age as independent risk factors for contralateral renal cell carcinoma after surgery for unilateral renal cell carcinoma. A longer primary-free interval was associated with a better prognosis. When calculating disease specific survival from the diagnosis of the first renal cell carcinoma, the primary-free interval was an independent prognostic factor.
Conclusions: Long-term survival rates of metachronous, bilateral renal cell carcinoma are moderate. von Hippel-Lindau disease, a family history of renal cell carcinoma, multifocal first renal cell carcinoma and young patient age are independent risk factors for contralateral renal cell carcinoma. These risk factors support close and extended abdominal surveillance following nephrectomy for unilateral renal cell carcinoma. Patients with a longer primary-free interval have a more favorable prognosis.