Long-Term Effect of Bleomycin on Respiratory Function Tests in Pediatric Cancer Patients.

Chemotherapy and radiotherapy which are used in the management of cancer have acute and chronic adverse effects on various organs. Patients develop pulmonary damage due to mantle zone irradiation and bleomycin in the short or long-term. In this study, after the completion of treatment long-term pulmonary complications of the teatment were investigated in 30 pediatric patients (19 male, 11 female) with cancer aged between 72–229 months. Twelve of the patients used also chemotherapy in addition to 1020–3570 rad. of mantle zone irradiation (median 2177 rad.), whereas the remaining 18 had chemotherapy alone. All of the patients had completed their treatment approximately 3,8 years ago, and the total dose of bleomycin they used was 12–180 mg. (median 69,83). All of the patients underwent physical examination, and complete blood count, chest radiograph and spirometric tests to measure lung volumes were also performed. Additionally, in 20 patients single breath technique to measure the diffusing capacity for carbon monoxide was carried out. Physical examination of cardiopulmonary system revealed normal findings and none of our patients had a cardiopulmonary symptom. Chest radiograph was normal in 25 (83,3%) but it was abnormal in 5 patients.

Lung volume measurements were normal in 21 (71%), but were abnormal in 9 (29%) patients. Of these 9 patients 23% had restrictive, 3% had combined and 3% had obstructive disorders. In our study, no correlation could be shown between the impaired respiratory function tests and irradiation and bleomycin doses used. In 3 (10%) out of 20 patients in whom the diffusing capacity test for carbon monoxide was performed, decreases in diffusing capacity for carbon monoxide were found. One of these patients had both high dose bleomycin (156 mg.) and mantle zone irradiation (2160 rad.), whereas the remaining 2 had low dose bleomycin (30–63 mg.) alone and received no radiotherapy.

The diffusing capacity test for carbon monoxide which returns to normal values in short -term is less valuable than the measurement of lung volumes for the long-term follow-up evaluation of respiratory functions in these patients. Generally, in our late phase study (3,8 years after the completion of therapy), there was a low rate of impairment in diffusing capacity test for carbon monoxide, but the rate of impairment in lung volumes was much higher. This finding was compatible with most of the related literature.

In conclusion, in pediatirc cancer patients respiratory function tests should be performed during the treatment and also after the completion of treatment in order to follow the course of pulmonary function impairment.