Enhanced pulmonary toxicity with bleomycin and radiotherapy in oat cell lung cancer.

In a recently completed study, combination chemotherapy consisting of bleomycin, adriamycin, cyclophosphamide, and vincristine was given to 29 patients with oat cell lung cancer. There were no cases of pulmonary fibrosis in these 29 patients. Although several of these patients had prior radiotherapy, none had concomitant radiotherapy and chemotherapy. This same four-drug chemotherapy regimen was combined with concomitant radiotherapy in 13 patients with oat cell lung cancer. There were three cases of fatal pulmonary fibrosis and two other cases of clinically significant pulmonary fibrosis. All five cases of pulmonary fibrosis occurred several weeks after completion of a six-week course of bleomycin (total dosage 90 units). It is concluded that bleomycin cannot be safely administered while patients are receiving radiotherapy to the lung.