Early life environment, life history and risk of endometrial cancer.

Endometrial cancer risk is influenced by reproductive behaviours, including parity and breastfeeding, and timing of life history events such as age at menarche and menopause. One potential mechanism by which altered reproductive strategies may influence endometrial cancer risk is through exposure to reproductive hormones. Current theory suggests that high lifetime exposure to oestrogen, unopposed by progesterone, increases endometrial cancer risk; here we suggest that progesterone deficiency itself may also play a significant role. Additionally, given that reproductive profile variables are themselves influenced by early childhood conditions, we hypothesise that endometrial cancer risk may be influenced by the childhood psychosocial environment as mediated through changes to adolescent and adult reproductive behaviours and hormone exposures. Investigating reproductive cancers, including endometrial cancer, using a life history approach may help to increase understanding of why these cancers occur and potentially help implementation of early detection and screening processes in the future.