Small testicles with impaired production of sperm in adult male survivors of childhood malignancies.

Testicular size has been studied in 66 adult men who survived leukemia (n = 14) or cancer (n = 52) in childhood. Mean follow-up time was 14.5 years. The testicular size was measured as the length and breadth in mm; testicular volume index was calculated. Serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and prolactin were measured. A sperm sample was obtained from 46 men. The patients had smaller testicles than healthy medical students; 51 had small testicles. The size was the smallest in patients who survived leukemia. Multivariate analysis showed that the variables with independent effects on testicular size were cranial and testicular irradiation and therapy with cyclophosphamide. Sperm production was dependent on testicular size. We conclude that determination of serum FSH combined with testicular size may offer a practical approach for predicting the subsequent testicular damage in boys with malignancies.