Pettersson B, Adami H O, Bergström R, Johansson E D
Acta Obstet Gynecol Scand. 1986;65(3):247-55. doi: 10.3109/00016348609155179.
A case-control study was undertaken to investigate the influence of reproductive factors on the risk of developing endometrial carcinoma. The study comprised 254 women with newly diagnosed endometrial carcinoma, resident in a defined geographical area, and 254 age-matched population controls. Nulliparity and late menopause were positively associated with endometrial carcinoma. Each additional full-term pregnancy resulted in a decrease in the risk by 16%. The importance of parity and menopausal age decreased with increasing life span, and in women older than 69 years these two variables did not discriminate significantly between cases and controls. The calculated number of years of menstruation (the "menstruation span") was used as a combined measure of the impact of parity, age at menarche and age at menopause on the risk of developing endometrial carcinoma. The patients had a significantly longer mean menstruation span than the controls (33.6 versus 31.2 years; p less than 0.001) and a longer span than 39 years gave a 4.2 times higher risk than one shorter than 25 years. It is suggested that the total length of time for which a woman is exposed to unopposed estrogen is important and that the effect of this hormonal influence is time-limited.
开展了一项病例对照研究，以调查生殖因素对子宫内膜癌发病风险的影响。该研究纳入了254名新诊断为子宫内膜癌的女性，她们居住在一个特定的地理区域，以及254名年龄匹配的人群对照。未生育和绝经晚与子宫内膜癌呈正相关。每增加一次足月妊娠，风险降低16%。随着寿命延长，生育次数和绝经年龄的重要性降低，在69岁以上的女性中，这两个变量在病例组和对照组之间没有显著差异。计算出的月经年限（“月经跨度”）被用作衡量生育次数、初潮年龄和绝经年龄对子宫内膜癌发病风险综合影响的指标。患者的平均月经跨度显著长于对照组（33.6年对31.2年；p<0.001），月经跨度超过39年的女性患癌风险是月经跨度短于25年的女性的4.2倍。研究表明，女性暴露于无对抗雌激素的总时长很重要，且这种激素影响的作用是有时间限制的。
