BACKGROUND: Bilateral renal cell carcinoma (RCC) exists in hereditary forms (von Hippel-Lindau disease, hereditary papillary renal cell carcinoma, and hereditary clear cell renal carcinoma) associated with various chromosomal abnormalities, and non-hereditary, apparently sporadic forms. The focus of this study is the clinical description of the latter entity. METHODS: Synchronous and asynchronous bilateral RCC were identified from a prospective database of 698 consecutive patients undergoing operation for RCC between July 1989 and December 1997 at Memorial Sloan-Kettering Cancer Center. Non-familial RCC was defined as that occurring in those patients without a family or hereditary history of RCC. Patients' records were evaluated for presentation, surgical approach used, and pathology. Actuarial survival from the date of initial operative treatment until the date of last follow-up or death was determined using the Kaplan-Meier method. Comparisons between groups were made using the Mann-Whitney test. RESULTS: Thirty-three of 698 (4.7%) patients operated for RCC had bilateral disease. Four of the 33 (12.1%) patients had either VHL or documented hereditary RCC, and 29 of 33 (87.9%) had non-familial RCC. Of the 29 patients, histology was conventional (clear cell) in 17 patients, papillary in 5, oncocytoma in 3, and unclassified in 3. One patient had a conventional (clear cell) histology in the first nephrectomy specimen and chromophobe renal cell carcinoma in the second. Partial nephrectomy was used in 100% of patients. Median follow-up time was 52 months. Actuarial 5-year overall survival was 84.5%, and actuarial disease-specific survival was 93.3% at 5 years for the non-familial RCC patients. CONCLUSIONS: Non-familial bilateral RCC patients represent a distinct subpopulation of renal cancer patients with a good overall prognosis. Partial nephrectomy is an integral part of the surgical management. Although most bilateral tumors present synchronously, asynchronous lesions may occur many years after original nephrectomy, thus committing the patient to long-term follow-up.
