Pulmonary Function after Treatment for Childhood Cancer. A Report from the St. Jude Lifetime Cohort Study (SJLIFE)

The relationship between treatment-related impairment of pulmonary function in adult survivors of childhood cancer and subsequent physical function has not been studied. In this prospective evaluation of 606 adult survivors of childhood cancer, we sought to determine the risk factors for, as well as the functional impact of, clinically ascertained pulmonary function impairment. We measured FEV1, FVC, total lung capacity (TLC), and single-breath diffusing capacity of the lung for carbon monoxide corrected for hemoglobin (DlCOcorr), expressing the results as percent predicted and lower limit of normal (LLN) values, and we also assessed functional exercise capacity (6-minute-walk distance). Lung radiation exposure was expressed as the estimated percentage of lung tissue that received at least 10 Gy (V10). Associations of clinical and treatment factors with pulmonary function measures were assessed using log-binomial regression to calculate relative risks and 95% confidence intervals. The participants' median age at evaluation was 34.2 years, and the median elapsed time from diagnosis was 21.9 years. Among the sample population, 50.7% had an FEV1 percent predicted less than 80%, 47.2% had an FVC percent predicted less than 80%, 31.2% had a TLC percent predicted less than 75%, and 44.6% had DlCOcorr percent predicted less than 75%. Also, 49.0% had FEV1 less than the LLN on the basis of the Global Lung Function Initiative (GLI) criteria, and 45.4% had FVC less than LLN. Obstructive lung defects (FEV1/FVC,