Neuroblastoma and Leukemia after Induction of Maternal Ovulation

Abstract

AIM: To estimate the contribution of ovulatory agents to the occurrence of neuroblastoma and leukemia in children. MATERIALS AND METHODS: We studied cases registered in the Japan Children's Cancer Registry from 1985 to 2004. Among them, the mothers of 15155 pediatric patients received no medications before pregnancy (group without medications) and those of 95 patients were given ovulatory medications (ovulatory group). The frequency of each disease (%) in the groups was calculated. If medications before pregnancy make no contribution to the occurrence of malignant neoplasms of children, the frequency of each disease in the ovulatory group should be the same as that in the group without medications. Based on this assumption, an expected value was calculated for each disease. P values were calculated through Poisson distribution, employing "expected numbers" and "observed numbers." RESULTS: In the ovulatory group, there were significantly more neuroblastoma patients (31 cases) than expected (18.32) (P=0.001), and significantly less acute lymphocytic leukemia patients (19) than expected (26.78) (P=0.037). There was no significant difference concerning acute non-lymphocytic leukemia patients (5 vs 9.00) (P=0.074). In the subgroup whose ages ranged from 1 to 4 years, there were significantly more neuroblastoma patients, too. In the subgroups of both males and females, there were significantly more neuroblastoma patients. In the subgroup of females, the number of cases with acute lymphocytic leukemia was significantly low. CONCLUSIONS: Ovulatory agents promote the occurrence of neuroblastoma whereas they suppress the occurrence of acute lymphocytic leukemia.