Abstract
PURPOSE: This study was undertaken to evaluate the incidence of pulmonary disease among patients treated with radiation therapy (RT) for pulmonary metastases (PM) from Wilms tumor (WT). PATIENTS AND METHODS: We reviewed records of 6,449 patients treated on National Wilms Tumor Studies-1, -2, -3, and -4 whose flow sheets or annual status reports documented one of several pulmonary conditions. Cases were fully evaluable if pulmonary function test (PFT) results were available, pulmonary fibrosis was identified on a chest radiograph or was listed as the primary or a contributing factor to death. Partially evaluable cases were those for whom PFT results could not be obtained. We evaluated the relationship between RT factors and the occurrence of pulmonary disease using hazard ratios (HRs) and cumulative incidence, treating death as a competing risk. RESULTS: Sixty-four fully evaluable and 16 partially evaluable cases of pulmonary disease were identified. The cumulative incidence of pulmonary disease at 15 years since WT diagnosis was 4.0% (95% confidence interval [CI] 2.6-5.4%) among fully evaluable and 4.8% (95% CI 3.3-6.4%) among fully and partially evaluable patients who received lung RT for PM at initial diagnosis. Rates of pulmonary disease were substantially higher among those who received lung RT for PM present at initial diagnosis or relapse compared to those who received no RT or only abdominal RT (HR 30.2, 95% CI 16.9-53.9). CONCLUSION: The risk of pulmonary disease must be considered in evaluating the risk:benefit ratio of lung RT for the management of PM from WT.