Testicular function of survivors of childhood cancer: A comparative study between ifosfamide- and cyclophosphamide-based regimens

Purpose: This study aimed at comparing gonadal toxicity of ifosfamide versus cyclophosphamide received during childhood. Methods: The evaluation was based on basal FSH measurement. LH and testosterone were also measured in most of the patients. One hundred patients had received ifosfamide and 59 had received cyclophosphamide. Results: Median age at treatment was 11.2 years. The median interval since treatment was 10.7 years (range 4.1-20.2) and median age at evaluation was 21.4 years (17.5-36.1). The median dose of ifosfamide and of cyclophosphamide was 54 g/m² (18-114) and 8.3 g/m² (4.6-22), respectively. All but two males had normal testosterone levels. FSH was abnormal in 28/59 patients (47.5%) after receiving cyclophosphamide and was within the normal range in 94/100 patients (94%) after receiving ifosfamide. Conclusions: These results show that ifosfamide is associated with a lower risk of gonadal damage than cyclophosphamide. The risk of abnormal FSH increased with the cumulative dose of cyclophosphamide.