BREAST-CANCER INCIDENCE BEFORE AGE-55 IN RELATION TO PARITY AND AGE AT FIRST AND LAST BIRTHS - A PROSPECTIVE-STUDY OF ONE MILLION NORWEGIAN WOMEN
BREAST-CANCER INCIDENCE BEFORE AGE-55 IN RELATION TO PARITY AND AGE AT FIRST AND LAST BIRTHS - A PROSPECTIVE-STUDY OF ONE MILLION NORWEGIAN WOMEN
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DOI：
10.1097/00001648-199411000-00008
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发表时间：
1994-11-01
期刊：
影响因子：
5.4
通讯作者：
KVALE, G
中科院分区：
文献类型：
--
作者：
ALBREKTSEN, G;HEUCH, I;KVALE, G
我们在挪威的一个大型国家年轻女性队列中研究了乳腺癌、胎次和初产和末产年龄之间的关系。我们通过泊松回归分析，以胎次和最后（最近）出生的年龄作为时间相关变量，估计相对发病率。共有1,071,795名妇女参与了随访，年龄在20-54岁之间，共贡献了16,643,883人年。随访时间1个月至34.5年。在随访期间，4302名女性被诊断出患有乳腺癌。根据首次和最后一次分娩的年龄进行调整后，高胎次与总体降低乳腺癌风险相关（发病率比= 0.46,95%可信区间= 0.36-0.59，对于有五个或五个以上孩子的妇女和单胎妇女）。然而，在20-29岁的妇女中，结果表明，随着胎次的增加，风险增加（发病率罕见比= 1.25；95%置信区间= 0.64-2.45，有三个孩子的妇女和单胎妇女）。高胎次的保护作用在20岁以前头胎的妇女中特别强，而在30岁或30岁以上头胎的妇女中则相当弱。在对其他因素进行调整后的分析中，第一胎和最后一胎年龄较低都与乳腺癌风险降低有关，与最后一胎年龄的关联略强。
We examined the relation between breast cancer, parity, and age at first and last births in a large national cohort of young women in Norway. We estimated relative incidence rates by Poisson regression analyses of person-years at risk with parity and age at last (most recent) birth as time-dependent variables. A total of 1,071,795 women were included in follow up, contributing a total of 16,643,883 person-years in the age range 20-54 years. Follow up rimes ranged from 1 month to 34.5 years. A rod of 4,302 women were diagnosed with breast cancer during follow-up. With adjustment for age at first: and last births, high parity was associated with an overall reduced risk of breast cancer (incidence rate ratio = 0.46 95% confidence interval = 0.36-0.59 for women with five or more children us uniparous women). Among women age 20-29 years, however, the results suggested an increase in risk with increasing parity (incidence rare ratio = 1.25; 95% confidence interval = 0.64-2.45 for women with three children us uniparous women). The protective effect of high parity was particularly strong among women with first birth before the age of 20 years and rather weak among those with first birth at age 30 years or more. Low ages at: first and last births were both associated with reduced breast: cancer risk in analyses with adjustment for the other factor, with the association with age at last birth being slightly stronger.