论文标题：Pregnancy duration and breast cancer risk

期刊：

作者：Anders Husby, Jan Wohlfahrt, Nina Øyen, Mads Melbye

发表时间：2018/10/23

数字识别码：10.1038/s41467-018-06748-3

原文链接：

微信链接：

根据《自然-通讯》发表的一项观察性研究Pregnancy duration and breast cancer risk，乳腺癌风险降低与妊娠期34周及以上有关联。

图1：妊娠期与乳腺癌相对风险的关系。图源：Husby等

长期以来，怀孕的次数与时间点一直被和乳腺癌的风险变化关联起来；特别是年轻时（30岁以下）足月妊娠和较多的分娩次数一直被和乳腺癌风险降低关联起来。然而，目前尚不清楚这些因素如何影响乳腺癌的发展。

图2：与丹麦未生育女性相比，不同社会经济因素对第一次分娩女性的乳腺癌长期相对风险的影响。图源：Husby等

丹麦国家血清研究院的Mads Melbye及其同事利用丹麦的国家分娩与癌症登记数据，建立了一个覆盖230万名妇女的队列，并评估了妊娠时长与长期乳腺癌风险之间的关系。他们发现乳腺癌风险下降与妊娠期持续至少34周有关，而妊娠期不超过33周不会带来风险降低。

他们还发现，包括分娩次数和社会经济地位在内的其它因素不能解释这种关联。此外，该分析在包含160万名妇女的等价挪威队列中得到了重复。作者提出，在妊娠第34周左右可能发生了特别的生物学效应，以上发现或有助于调查这种效应背后的起因。

摘要：Full-term pregnancies reduce a woman’s long-term breast cancer risk, while abortions have been shown to have no effect. The precise minimal duration of pregnancy necessary to lower a woman’s breast cancer risk is, however, unknown. Here we provide evidence which point to the protective effect of pregnancy on breast cancer risk arising precisely at the 34th pregnancy week. Using a cohort of 2.3 million Danish women, we found the reduction in breast cancer risk was not observed for pregnancies lasting 33 weeks or less, but restricted to those pregnancies lasting 34 weeks or longer. We further found that parity, socioeconomic status, and vital status of the child at birth did not explain the association, and also replicated our finding in data from 1.6 million women in Norway. We suggest that a distinct biological effect introduced around week 34 of pregnancy holds the key to understand pregnancy-associated breast cancer protection.

阅读论文全文请访问：

期刊介绍：() is an open access journal that publishes high-quality research from all areas of the natural sciences. Papers published by the journal represent important advances of significance to specialists within each field.

The 2017 journal metrics for Nature Communications are as follows:

•2-year impact factor: 12.353

•5-year impact factor: 13.691

•Immediacy index: 1.829

•Eigenfactor® score: 0.92656

•Article Influence Score: 5.684

•2-year Median: 8

（来源：明升手机版(明升中国)）