Okamura Chikako, Tsubono Yoshitaka, Ito Kiyoshi, Niikura Hitoshi, Takano Tadao, Nagase Satoru, Yoshinaga Kohsuke, Terada Yukihiro, Murakami Takashi, Sato Shinji, Aoki Daisuke, Jobo Toshiko, Okamura Kunihiro, Yaegashi Nobuo
Department of Obstetrics and Gynecology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Tohoku J Exp Med. 2006 Feb;208(2):109-15. doi: 10.1620/tjem.208.109.
The incidence of endometrial cancer is rapidly increasing in Japan. Although the risk factors in European populations have been well described, there are few epidemiologic studies regarding risk factors for endometrial cancer in Japanese women. This hospital-based case-control study among Japanese women was carried out from 1998 to 2000. The cases were selected from women with endometrial cancer (n =155), and the controls selected from women attending the university gynecological outpatient clinic for cervical cancer screening (n = 96). Subjects were interviewed to ascertain breast feeding practices, contraceptive usage, as well as potential risk factors for endometrial cancer. We observed a lower risk of endometrial cancer associated with oral contraceptive (OC) and a higher risk associated with higher body mass index (BMI), and older ages at first and last delivery. Gravidity reduced odds ratio (OR) for endometrial cancer to 0.34 (95% confidence interval [CI] 0.13-0.92). Compared with parous women who had never breastfed, the multivariate OR for women with a history of breastfeeding was 0.37 (95% CI, 0.17-0.82). Additionally, a greater lapse of time since breastfeeding increased OR for endometrial cancer by over three times. In conclusion, the present study has indicated that breastfeeding reduces the risk of endometrial cancer in Japanese women.
子宫内膜癌的发病率在日本正迅速上升。尽管欧洲人群中的风险因素已得到充分描述，但关于日本女性子宫内膜癌风险因素的流行病学研究却很少。这项基于医院的针对日本女性的病例对照研究于1998年至2000年开展。病例选自患有子宫内膜癌的女性（n = 155），对照选自到大学妇科门诊进行宫颈癌筛查的女性（n = 96）。对受试者进行访谈以确定母乳喂养情况、避孕措施使用情况以及子宫内膜癌的潜在风险因素。我们观察到口服避孕药（OC）与子宫内膜癌风险降低相关，而较高的体重指数（BMI）、首次分娩和末次分娩年龄较大则与风险升高相关。妊娠使子宫内膜癌的比值比（OR）降至0.34（95%置信区间[CI] 0.13 - 0.92）。与从未母乳喂养的经产妇相比，有母乳喂养史女性的多因素OR为0.37（95% CI，0.17 - 0.82）。此外，母乳喂养后时间间隔越长，子宫内膜癌的OR增加超过三倍。总之，本研究表明母乳喂养可降低日本女性患子宫内膜癌的风险。
