Longitudinal assessment of Leydig cell function in male survivors of childhood cancer.

Background: As the number and longevity of childhood cancer survivors increases, assessing treatment-associated late effects remains crucial. We longitudinally examined the incidence of and associated risk factors for Leydig cell dysfunction (LCD) and Leydig cell failure (LCF) in men treated for pediatric cancers at our institution.

Procedure: We performed a retrospective longitudinal cohort study of adult male survivors treated for various childhood cancers who are at risk for LCD. The outcomes of interest were serum testosterone and luteinizing hormone (LH) levels during childhood and adulthood. Risk factors assessed included treatment with stem cell transplant, total body irradiation (TBI), and exposure to alkylating agents.

Results: Out of 118 eligible subjects, 7.6% had LCF and 14.4% had LCD. Median age at last testosterone level was 20 years. Subjects with sufficient testosterone levels in adulthood (N = 105) remained sufficient for a mean of 11.1 years following completion of cancer treatment. We found significant associations between LCF and treatment with TBI (p < .003) and between LCF in adulthood and testosterone insufficiency in childhood (p < .001). No statistically significant association was found between LCF and cyclophosphamide equivalent dose greater than 20 g/m (p = .2). LCF/LCD occurred in a small number of nonirradiated patients treated with the highest doses of alkylators.

Conclusions: Incidence of LCF and LCD are low in male survivors of childhood cancer. Longitudinally, there is an association between childhood testosterone insufficiency and LCF in adulthood. Alkylating agents and stem cell transplant without TBI were not associated with LCF in our study.