Prognosis for patients with unilateral Wilms' tumor in Rio de Janeiro, Brazil, 1990-2000

Objective To analyze the survival and the main prognostic factors among patients with unilateral Wilms' tumor patients. Methods The study cohort included 132 patients with unilateral Wilms' tumor aged under 15 years, who were enrolled in a pediatric oncology service. Survival curves were calculated using the Kaplan-Meier method and the prognostic factors were analyzed using the Cox proportional hazards model. Results The overall survival rate for five years was 84.6%. The survival probabilities for disease in stages I, II, III and IV stages were: 100%, 94.2%, 83.2% and 31.3%, respectively. The survival rate was 89.4% for patients with favorable histology: 66.7% for focal anaplasia and 40% for diffuse anaplasia. All patients with stage IV disease and diffuse anaplasia died (n = 4). All patients with stage I disease, regardless of histology, remained alive at the end of the follow-up period. Conclusions Among the variables selected for the final model, only the staging and the histology remained associated with high risk of death risk, while patients aged 24-47 months presented better prognosis than the other patients. These results showed the importance of establishing the diagnosis at an early stage, and that the histology is fundamental for guiding the appropriate therapy.