A MALE-FEMALE DIFFERENTIAL IN TUMOUR INCIDENCE

Data are presented to show that there is a lower incidence of tumours in women than in men if lesions of the dissimilar sex organs and of the lung, in which the influence of cigarette smoking is of major importance, are excluded. Some part of this difference may be due to environmental factors, to the effect of the differences in the steroid hormones of the two sexes or to a difference in physical size and thence of the number of cells available for neoplastic change. It is suggested in addition that the capacity for immunological control and for rejection of incipient cancerous cells is greater in the female than the male and that this difference also plays a part in the differential incidence of tumours in the two sexes. This work was carried out with the aid of a research grant from the Welsh Hospital Board. © 1969, The British Empire Cancer Campaign for Research. All rights reserved.