Characteristics of the Prevention and Treatment of Gynecological Cancer in Japan

Abstract

Various interactions between biological, psychological, and social factors should be considered for the prevention of cancer. Endometrial cancer, which is a common gynecological cancer worldwide, ranks 6th among all cancers in women when the incidence has been ageadjusted [1]. The rate of incidence of endometrial cancer was 6.5 (per 100,000 women) in 2015, which is a four-to five-fold increase over the past 3 decades [2]. A large variation among the incidence rates internationally has been reported and the incidence rate in Japan is lower than that in Western countries; however, the incidence of endometrial cancer has increased 1.5-fold among the Japanese migrants in the United States and three-to four-fold among the Japanese Americans born in the United States when compared that of Japanese women living in Japan [3]. These findings suggest that a health-related lifestyle is related to the risk of endometrial cancer and epidemiological studies have investigated the dietary effects on endometrial cancer [4]. Thus, we have investigated the food intake frequency for the patients and healthy volunteers by using a frequency questionnaire. Results of a case-control study showed that the consumption of green tea and coffee were negatively associated with the risk of endometrial endometrioid adenocarcinoma (EEA) [5]. Furthermore, our study suggested that a higher intake of vegetables, peanuts, fish, and boiled eggs was associated with a reduced risk of EEA. A higher intake of instant noodles, instant food items, and deep-fried foods was associated with an increased risk of EAA when compared that of Japanese women who have a lower intake [6]. These findings suggest that foods containing polyphenols with antioxidant properties, omega-3 fatty acids [7], and vitamin D [8] could play a role in prevention, while instant foods that are high in rich fatty acids could increase the risk of EEA. Also, it is reported that Japanese foods are rich in these nutrients [9,10]. Thus, the intake of traditional Japanese foods, which is characterized by the relatively high amounts of fish and vegetables when compared to that of the Western diet, might be appropriate for the prevention of EEA in Japanese women.