Bleomycin-associated lung toxicity in childhood cancer survivors.

Abstract

9591 Background: Bleomycin has been established as a pulmonary toxin, but the risk for toxicity in survivors of childhood cancer is poorly characterized. Methods: We conducted a cross-sectional study of lung function in survivors of childhood Hodgkin lymphoma and germ cell tumor treated with bleomycin at our institution between 1997 and 2010. We assessed their most recent post-therapy pulmonary function test (PFT). Spirometry and lung volumes were categorized as normal, restrictive, obstructive or mixed. Diffusing capacity of carbon monoxide (DLCO) was categorized as normal or abnormal. Results: 195 patients were treated with bleomycin. Ten died of non-pulmonary causes. Of 185 survivors, 143 (77%) had complete data available for analysis. Median cumulative bleomycin dose was 60U/m2 (IQR 30-60). Three patients (2%) had a history of acute bleomycin toxicity. PFTs were performed a median of 2.3 years (IQR 1.4-4.9) from completion of therapy. Spirometry was abnormal in 58 patients (41%); of whom 5 (9%) had respiratory symptoms. 42 (70%) had obstructive, 11 (18%) restrictive and 5 (9%) mixed ventilatory defects. Abnormalities were mild in 53 (91%), moderate in 3 (5%) and severe in 2 (4%). DLCO was abnormal in 27 patients, 26 (96%) of whom had mildly reduced DLCO and were asymptomatic. Univariate analysis did not demonstrate a significant association between gender, smoking, lung metastases, lung radiation, chemotherapy regimen, or autologous transplant and abnormal lung function. Disease relapse was associated with abnormal lung function (p=0.01). Smoking (p=0.04) and relapse (p=0.03) were associated with abnormal DLCO. The odds ratio of developing abnormal spirometry for each 1unit/m2 increase in bleomycin was 1.01 (95% CI 1.00-1.02, p=0.07). Conclusions: Childhood cancer survivors treated with bleomycin frequently have evidence of asymptomatic abnormalities on PFT. The current recommendation for pulmonary function testing in childhood cancer survivors appears justified.