Abstract
PURPOSE: To assess rates and causes of mortality in patients with Wilms tumor (WT). METHODS: Through 2002, 6,185 patients enrolled onto the National Wilms Tumor Study between 1969 and 1995 were actively observed. Deaths were classified on the basis of medical records as the result of original disease, late effects (including second malignant neoplasms [SMNs], cardiac causes, pulmonary disease, and renal failure), or other causes. Standardized mortality ratios (SMRs) and Cox regression were used to assess the effects of sex, age, and calendar period of diagnosis on mortality. RESULTS: Within 5 years of WT diagnosis, 819 deaths occurred, and 159 deaths occurred among 4,972 known 5-year survivors. The SMR was 24.3 (95% CI, 22.6 to 26.0) for the first 5 years, was 12.6 (95% CI, 10.0 to 15.7) for the next 5 years, and remained greater than 3.0 thereafter. For deaths in the first 5 years, the mortality risk decreased by 5-year calendar period of diagnosis (rate ratio [RR] = 0.78 per period). No such trend occurred for later deaths. Among 5-year survivors, 62 deaths were attributed to late effects of treatment or disease, including 27 to SMNs. A trend of decreased risk with calendar period of diagnosis was observed for late-effects mortality (RR = 0.86; 95% CI, 0.67 to 1.10) and for SMN mortality (RR = 0.82; 95% CI, 0.55 to 1.21). CONCLUSION: Although the survival outlook for WT patients has improved greatly over time, survivors remain at elevated risk for death many years after their original diagnosis.