Pulmonary function in children treated for rhabdomyosarcoma

Chemotherapy, radiation therapy, and surgical intervention have markedly improved the survival of patients treated for rhabdomyosarcoma. Unfortunately, the therapy may have deleterious effects on the lung. Pulmonary functions tests were obtained from 17 patients treated for rhabdomyosarcoma because of our concern regarding potential pulmonary dysfunction in this group of patients who had received bleomycin, which is known to be associated with lung injury. Mean age at the time of the diagnosis of rhabdomyosarcoma was 10.1 (+/- 7.2) years (range 0.01-23.5 years). The mean age at the time of pulmonary function testing was 17.0 (+/- 7.5) years (range 5.8-34.0 years). Study patients reportedly had no pulmonary symptoms. Approximately 87% of study patients had a restrictive ventilatory impairment on pulmonary function testing as measured by total lung capacity (TLC) values less than the lower limit of normal. Approximately 70% of study patients had carbon monoxide diffusing capacity (DLCO) values less than the lower limit of normal. There were no significant differences in pulmonary function parameters when male study patients were compared to female study patients. There was a statistically significant lower forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ratio (P=0.03) and percent predicted forced expiratory flow at 25-75% of the FVC (FEF25-75; P=0.03) in the group of patients diagnosed with rhabdomyosarcoma over 8 years of age as compared to those individuals diagnosed under 8 years of age. In addition, there were no statistically significant differences in pulmonary function when the variables of sex and age at diagnosis (as outlined above) were studied in combination. In summary, we identified a high incidence of restrictive ventilatory abnormalities in a group of individuals (predominantly children) treated for rhabdomyosarcoma as well as a significantly lower FEV1/FVC ratio and percent predicted FEF25-75 in the group of patients diagnosed with the neoplasm over 8 years of age. Individuals caring for such patients are encouraged to obtain pre- and sequential posttreatment pulmonary function tests.