Kvåle G, Heuch I, Nilssen S
Department of Hygiene and Social Medicine, University of Bergen, Norway.
Cancer Detect Prev. 1991;15(5):369-77.
Relationships between reproductive factors and cancer of the breast and genital organs were investigated in a prospective study of 63,090 Norwegian women. During followup from 1961 through 1980 1565 cases of breast cancer, 422 cases of cancer of the corpus uteri, and 471 cases of ovarian cancer were diagnosed. High parity was associated with low risk of cancer of the breast, corpus uteri, and ovary in analyses with adjustment for age at first birth. Age at first birth and age at last birth were positively associated with risk of breast cancer and inversely associated with endometrial cancer, whereas no clear associations were observed with ovarian cancer. Results suggest that the effect of a pregnancy on cancer risk is mediated, at least in part, by different mechanisms for these three sites. Age at menarche was inversely and age at menopause positively related to risk of breast and endometrial cancer, whereas no association was observed for ovarian cancer. In analyses of squamous cell carcinoma of the cervix uteri, an association with reproductive factors was expected from the known relationships with sexual habits. However, this cannot account for the high risk observed in this study in women with early age at first birth.
在一项对63090名挪威女性的前瞻性研究中，调查了生殖因素与乳腺癌和生殖器官癌症之间的关系。在1961年至1980年的随访期间，诊断出1565例乳腺癌、422例子宫体癌和471例卵巢癌。在对首次生育年龄进行调整的分析中，高生育次数与乳腺癌、子宫体癌和卵巢癌的低风险相关。首次生育年龄和末次生育年龄与乳腺癌风险呈正相关，与子宫内膜癌风险呈负相关，而与卵巢癌未观察到明显关联。结果表明，怀孕对癌症风险的影响至少部分是由这三个部位的不同机制介导的。初潮年龄与乳腺癌和子宫内膜癌风险呈负相关，绝经年龄与乳腺癌和子宫内膜癌风险呈正相关，而与卵巢癌未观察到关联。在对子宫颈鳞状细胞癌的分析中，根据与性行为习惯的已知关系，预计与生殖因素有关联。然而，这无法解释本研究中首次生育年龄早的女性所观察到的高风险。
