Hinkula Marianne, Pukkala Eero, Kyyrönen Pentti, Kauppila Antti
Department of Obstetric and Gynaecology, University of Oulu, PL 24, FIN-90029 OYS, Finland.
Gynecol Oncol. 2006 Oct;103(1):207-11. doi: 10.1016/j.ygyno.2006.02.025. Epub 2006 Apr 3.
Parity is known to induce protective effects on ovarian cancer. This study aimed to evaluate how far upon births the protection reaches, the effect of age at first birth, the interval between births in the whole population and the length of time from the first to the last birth and from the last birth to cancer among postmenopausal women.
The population-based cohort consisted of 87,929 grand multiparous (GM) women, i.e. women with at least 5 deliveries. Standardised incidence ratios (SIRs) were calculated by dividing the number of observed cancer cases by the expected number based on the national incidence rates, both extracted from the population-based Finnish Cancer Registry. Conditional logistic regression for the case-control design nested in the GM cohort was used to estimate proportional hazards by different factors.
The SIR for ovarian cancer among GM women was low (418 cases; SIR 0.64, 95% confidence interval 0.58-0.69). Further births over five did not give additional protection. The relative risk did not vary significantly by age at first birth or interval between the births in any histological subtype.
The risk of ovarian cancer was low in all GM women no matter how many children and at which ages they had delivered or contracted cancer.
已知生育次数对卵巢癌具有保护作用。本研究旨在评估这种保护作用在生育后能持续多久，首次生育年龄的影响，整个人口中生育间隔的影响，以及绝经后女性从首次生育到最后一次生育的时间长度和从最后一次生育到患癌的时间长度。
基于人群的队列由87929名多产妇女（GM）组成，即至少生育5次的妇女。标准化发病率（SIR）通过将观察到的癌症病例数除以基于国家发病率的预期病例数来计算，两者均取自基于人群的芬兰癌症登记处。在GM队列中嵌套的病例对照设计采用条件逻辑回归来估计不同因素的比例风险。
GM妇女中卵巢癌的SIR较低（418例；SIR 0.64，95%置信区间0.58 - 0.69）。超过5次的进一步生育并未提供额外保护。在任何组织学亚型中，相对风险在首次生育年龄或生育间隔方面均无显著差异。
所有GM妇女患卵巢癌的风险都较低，无论她们生育了多少子女、在什么年龄生育或患癌。
