Sex dependence of human intracranial gliomata

The age and sex distribution of 1223 cases of intracranial gliomata, diagnosed in the geographical area covered by the Mersey Regional Cancer Registry over the period 1961-70, are analysed. In children and adults, the intracranial gliomata predominates in males, the tumour incidence figures indicating a ratio of 3 : 2. For young adults, the tumour incidence increases with age and is approximately the same in males and females. It is not until the age group 45-49 years is reached that the tumour incidence in males is higher. The peak tumour incidence occurs at the same age in both sexes (60-64 years) and thereafter incidence declines with age. These results are compared with previously published human data, and with the findings of experimental studies in the rat. Factors including naturally occurring changes in the hormone levels are discussed, in an attempt to explain the observed age-related sex differences.