Gender affects survival for medulloblastoma only in older children and adults: a study from the Surveillance Epidemiology and End Results Registry.

BACKGROUND

Males have a higher incidence of medulloblastoma (MB) than females, but the effect of gender on survival is unclear. Studies have yielded conflicting results, possibly due to small sample sizes or differences in how researchers defined MB. We aimed to determine the effect of gender on survival in MB using a large data set and strict criteria for defining MB.

PROCEDURE

A sample of 1,226 subjects (763 males and 463 females) was identified from 1973 to 2002, using the Surveillance Epidemiology and End Results (SEER-9) registry. MB was strictly defined to exclude non-cerebellar embryonal tumors (primitive neuro-ectodermal tumors). Because children <3 years of age are known to have worse survival, patients were stratified by age <3 years at diagnosis (95 males, 82 females) and >3 years (668 males, 381 females).

RESULTS

Overall, there was no significant difference in survival between males and females (log rank P = 0.22). However, among subjects >3 years, females had significantly greater survival than males (log rank P = 0.02). In children <3 years, there was a non-significant trend toward poorer survival in females (median survival: males 27 months, females 13 months; log rank P = 0.24). This interaction between age group and gender was statistically significant (P = 0.03).

CONCLUSION

Females with MB have a survival advantage only in subjects >3 years. In children <3 years, females may even have poorer outcome. The effect of gender on survival and incidence in MB warrants additional biologic investigation, and may differ in very young children with MB.