Subsite (cervix/endometrium)-specific risk and protective factors in uterus cancer

In Japan the incidence of cervical cancer has been high, but has recently been decreasing gradually, while the incidence of endometrial cancer is running at lower levels but is gradually increasing. To clarify the common and/or specific risk and/or protective factors of cervical cancer(CC) in contrast with endometrial cancer (EC), a comparative case-control study was conducted at the Aichi Cancer Center Hospital, Japan. In total, 556 CC cases and 145 EC cases were included and 26,751 women, confirmed as free of cancer, were chosen as the common control group. Odds ratio and its 95% confidence interval (95%CI) for each exposure variable were estimated by using an unconditional logistic regression model adjusted for age and first-visit year. Habitual smoking and experience of pregnancy increased the risk of CC, while decreasing the risk of EC. Greater body mass index (>20), daily intake of fruit and more frequent intake of boiled or broiled fish (>1-2 times/week) decreased the risk of CC, whereas they increased the risk of EC. Daily intake of milk decreased the risk of CC. The results obtained from this study suggest that several EC-increasing risk factors are in fact CC-decreasing determinants. The observed risk reduction in both CC and EC by physical exercise and dietary control for health is noteworthy from the public health standpoint and warrants further investigation.