Cyclophosphamide is not associated with clinically relevant late pulmonary dysfunction in Dutch survivors of childhood cancer - The DCCSS-LATER 2 PULM sub-study.

BACKGROUND

Treatment for childhood cancer may increase the risk of long-term pulmonary complications and dysfunction. Pulmonary surveillance is recommended after established pulmonary toxic exposures, including bleomycin, busulfan, carmustine (BCNU), lomustine (CCNU), radiotherapy to a field exposing the lungs, and pulmonary surgery. However, the role of cyclophosphamide as a pulmonary toxic agent is debated.

AIM: To establish whether cyclophosphamide is associated with late pulmonary dysfunction among survivors of childhood cancer.

METHODS

In this multicenter Dutch Childhood Cancer Survivor Study (DCCSS)-LATER 2 PULM sub-study, we included 828 survivors with a median follow-up of 26.6 years, treated with cyclophosphamide and/or established pulmonary toxic treatment, or neither. Pulmonary function tests were used to measure the primary outcomes of diffusion impairment (diffusing capacity for carbon monoxide (DLCO) z-score), restriction (total lung capacity (TLC) z-score), and obstruction (forced expiratory volume in the first second/forced vital capacity (FEV1/FVC) z-score). Secondary outcomes comprised chronic cough, recurrent respiratory tract infections, shortness of breath, and supplemental oxygen need.

RESULTS

Diffusion and restrictive abnormalities were highly prevalent among those treated with established pulmonary toxic treatment, with cyclophosphamide (41.0 % and 50.4 %, respectively) and without (34.3 % and 41.9 %, respectively), and occurred less frequently in survivors treated with cyclophosphamide only (12.9 % and 7.3 %, respectively) or in survivor controls (9.9 % and 12.4 %, respectively). In multivariable analyses, cyclophosphamide did not have a clinically relevant effect on the primary or secondary outcomes.

CONCLUSIONS

This study suggests that cyclophosphamide is not associated with clinically relevant pulmonary dysfunction in long-term childhood cancer survivors.