Epidemiology and risk factors of endometrial cancer

The mortality and morbidity of endometrial cancer are increasing in Japan and a further increase is probably based on changes in the lifestyle of women. In this chapter, we have provided an overview of the evidence for risk factors and suppressors of endometrial cancer. However, there are several potential risk factors without convincing evidence. For example, alcohol intake is correlated with the rates of several cancers and is known to increase blood estrogen and decrease progesterone [44]. Many studies have investigated the link between endometrial cancer and alcohol, but a relationship has not been established [45]. In addition, the risk for endometrial cancer is 2.4-fold higher in women with a menopausal age of ≪52 years old compared with those aged ≫49 years. However, it is difficult to determine menopausal age and to distinguish anovulatory bleeding immediately before menopause from an irregular menstrual cycle and atypical genital bleeding due to endometrial cancer [13]. These factors are also often intricately interlinked, and thus further studies of the risk factors for endometrial cancer are required.