AGE AT 1ST BIRTH, PARITY AND RISK OF BREAST-CANCER - A METAANALYSIS OF 8 STUDIES FROM THE NORDIC COUNTRIES
AGE AT 1ST BIRTH, PARITY AND RISK OF BREAST-CANCER - A METAANALYSIS OF 8 STUDIES FROM THE NORDIC COUNTRIES
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DOI：
10.1002/ijc.2910460408
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发表时间：
1990-10-15
影响因子：
6.4
通讯作者：
TULINIUS, H
中科院分区：
文献类型：
--
作者：
EWERTZ, M;DUFFY, SW;TULINIUS, H
北欧国家的几项大型流行病学研究未能证实第一胎年龄与乳腺癌之间的关联，而不依赖于产次。为了评估是否缺乏把握度或国家之间的异质性可以解释这一点，对北欧国家8项基于人群的乳腺癌和生殖变量研究（3项队列研究和5项病例对照研究）进行了荟萃分析，共包括5，568例病例。它证实，低产次和晚育是乳腺癌风险的重要和独立的决定因素。与经产妇女相比，无产与30%的风险增加有关，每生育2胎，风险降低约16%。随着首次生育年龄的增加，风险呈显着增加趋势，与20岁之前首次生育的女性相比，35岁之后生育首次生育的女性风险增加40%。研究间的异质性检验对于任何检查的变量都不显著。在不存在偏倚的情况下，这表明几项单独的北欧研究可能没有足够的能力来检测荟萃分析中观察到的首次生育年龄的微弱影响。
Several large epidemiological studies in the Nordic countries have failed to confirm an association between age at first birth and breast cancer independent of parity. To assess whether lack of power or heterogeneity between the countries could explain this, a meta-analysis was performed of 8 population-based studies (3 cohort and 5 case-control) of breast cancer and reproductive variables in the Nordic countries, including a total of 5,568 cases. It confirmed that low parity and late age at first birth are significant and independent determinants of breast-cancer risk. Nulliparity was associated with a 30% increase in risk compared with parous women, and for every 2 births, the risk was reduced by about 16%. There was a significant trend of increasing risk with increasing age at first birth, women giving first birth after the age of 35 years having a 40% increased risk compared to those with a first birth before the age of 20 years. Tests for heterogeneity between studies were not significant for any of the examined variables. In the absence of bias, this suggests that several individual Nordic studies may have had too little power to detect the weak effect of age at first birth observed in the meta-analysis.