Effect of treatment for Hodgkin's disease on pulmonary function: results of a prospective study

Because each of very different treatments for Hodgkin's disease (HD) may result in a high rate of cure, attention is currently focused on toxicity. This prospective study was designed to assess the effects of mediastinal irradiation and bleomycin chemotherapy on pulmonary function.

Patients were treated from 1980 to 1990 on randomized controlled trials at Stanford University. Pulmonary function was tested before treatment (baseline), early after treatment (< 15 months), and more than 36 months posttherapy. Treatment options in the 145 patients were grouped as I (mediastinal radiotherapy), II (mediastinal radiotherapy plus bleomycin), and III (bleomycin) for analyses of variance (ANOVAs). A variety of regression models were used to predict early and late effects on pulmonary function.

A decrease in forced vital capacity (FVC) and diffusing capacity (DLCO) in the first 15 months after treatment followed by recovery after 36 months was observed for most patients. Patients who received mediastinal radiotherapy (RT) had a more pronounced reduction in pulmonary function and less complete recovery. Overall, 3 or more years after treatment, 32% of group I patients, 37% of group II patients, and 19% of group III patients had FVC values less than 80% of predicted, while only 7% of patients had a DLCO less than 80% of predicted. Linear regression identified baseline measurement as the only significant predictor of change in percent predicted FVC or DLCO; patients with higher baseline values had greater decrements after therapy. Mantle RT was the only significant treatment variable, predictive of FVC and DLCO within 15 months and FVC at 36 or more months. No patient experienced pulmonary toxicity severe enough to require hospitalization.

This prospective analysis of pulmonary function after treatment for HD showed that mediastinal RT was the only treatment variable that achieved statistical significance. Although there were no significant interactions between mediastinal RT and bleomycin or Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH) chemotherapy, the patient numbers were small after correction for mediastinal mass size and drug regimen such that an effect could have been missed. The mild reduction in pulmonary function should be factored into the overall assessment of morbidity risk for each of the potentially curative treatments included in this study. As with all reports of late effects, these data should be interpreted with respect to the population tested, details of the treatment administered, methods of measurement, and length of follow-up.