Prognostic factors and outcome in bilateral Wilms' tumor.

Twenty-one patients with bilateral Wilms' tumor are reviewed and the details of diagnosis, therapy, and survival presented. All patients had an abdominal mass at the time of diagnosis. Associated findings included hypertension, aniridia, and genitourinary anomalies. Favorable histologic features were found in all simultaneously occurring tumors and in the initial tumor in nonsimultaneous tumors. Eleven of the 18 patients with simultaneously occurring tumors survived for at least 2 years, for an overall 2-year survival rate of 61%, which was similar to the 2-year survival rate of 60% found in a review of 61 other simultaneously occurring bilateral Wilms' tumors reported in the literature since 1971. Two "front-end" factors that affected prognosis were the patient's age and the stage of the most advanced tumor at the time of diagnosis. A significantly better survival was found in children whose tumor was diagnosed before the age of 2 years and in patients who had Stage I or II disease in the most advanced tumor, as compared with those who had Stage III or IV disease. The overall survival rate in this series and in the literature review is much poorer than that reported for bilateral Wilms' tumor in the National Wilm's Tumor Study; some possible reasons for this are given. The authors' current approach to diagnosis and therapy is reviewed.