NIH 研究：两种「永久化学物」血中浓度较高者侵袭性乳腺癌风险更高
美国国立卫生研究院（NIH）11月5日发布研究结果：血液中两种常见全氟和多氟烷基物质（PFAS）浓度较高的女性，患雌激素受体阴性（ER 阴性）乳腺癌的几率更高。研究涉及的两种物质是全氟辛酸（PFOA）与全氟辛烷磺酸（PFOS）。
PFAS 是一大类用于常见消费品的化学物，因不易在环境中分解、可在人体内留存多年，俗称「永久化学物」。ER 阴性肿瘤缺少让雌激素帮助癌细胞生长的受体，与对雌激素有反应的乳腺癌相比，这类肿瘤往往更具侵袭性、预后较差，而学界对其风险因素所知较少。研究未发现这两种化学物与乳腺癌总体风险之间有明确关联。
研究团队测量了参与者在确诊前数年采集的血样中的17种 PFAS：PFOA 浓度最高组女性的 ER 阴性乳腺癌发病率比最低组高67%，PFOS 最高组则高93%、接近两倍；研究者强调，这些数字是组间相对差异，不是单个女性的患病概率。研究数据来自 NIH 国家环境健康科学研究所主持的 Sister Study，该研究2003至2009年间在美国与波多黎各招募了50,884名35至74岁女性，她们本人当时未患乳腺癌、但各有一名亲姐妹或同母异父姐妹曾确诊乳腺癌；本次 PFAS 分析纳入1,609名后来患乳腺癌的女性与2,269名对照者，研究结论并经对既往研究的荟萃分析确认。研究发表于《临床肿瘤学杂志》。
领导研究的 NIH Stadtman 研究员 Alexandra White 说，研究结果显示，包括 PFOA 与 PFOS 在内的某些遗留 PFAS 与 ER 阴性乳腺癌风险较高相关，这是一类更具侵袭性、已知风险因素很少的肿瘤。卫生与公众服务部部长 Robert F. Kennedy, Jr. 说，这项 NIH 研究把两种永久化学物与 ER 阴性乳腺癌较高风险联系起来、要求进一步调查，女性应得到环境化学物如何影响其健康的明确答案。第一作者 Che-Jung Chang 指出，PFAS 暴露仍属可改变因素，人们可采取步骤减少暴露，这些发现可能为预防开辟新路径。NIH 表示，PFOA 与 PFOS 已大体被淘汰并由新型 PFAS 取代，对新型替代物的乳腺癌风险仍需更多研究。
（来源：美国国立卫生研究院）
NIH Analysis Links Two 'Forever Chemicals' to Higher Risk of Aggressive Breast Cancer
The National Institutes of Health (NIH) released a study on November 5 finding that women with higher blood levels of two common per- and polyfluoroalkyl substances (PFAS), perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), were more likely to develop estrogen receptor-negative (ER-negative) breast cancer. No clear association was observed between the two chemicals and breast cancer risk overall.
PFAS are a large group of chemicals used in common consumer products; often called "forever chemicals," they do not break down easily in the environment and can remain in the body for years. ER-negative tumors lack the receptors that allow estrogen to help cancer cells grow; compared with breast cancers that respond to estrogen, they tend to be more aggressive and have worse outcomes, and scientists know less about what raises the risk of this type of breast cancer.
NIH researchers and their collaborators measured 17 PFAS in blood collected years before diagnosis. Women in the group with the highest PFOA levels had a 67% higher rate of ER-negative breast cancer than those in the lowest group; for PFOS the rate was 93% higher, nearly twice as high. The researchers stressed that these numbers describe relative differences between groups, not an individual woman's chance of developing breast cancer. The research drew on the Sister Study, led by NIH's National Institute of Environmental Health Sciences, which enrolled 50,884 women ages 35-74 in the United States and Puerto Rico from 2003 to 2009, each with a sister previously diagnosed with breast cancer. The PFAS analysis included 1,609 women who developed breast cancer and a comparison sample of 2,269 women, and the findings were confirmed using a meta-analysis of prior research. The study is reported in the Journal of Clinical Oncology.
"Our findings indicate that certain legacy PFAS, including PFOA and PFOS, are associated with a higher risk of ER-negative breast cancer, a more aggressive tumor type with few known risk factors," said NIH Stadtman Investigator Alexandra White, who led the study. HHS Secretary Robert F. Kennedy, Jr. said the study links two forever chemicals to a higher risk of ER-negative breast cancer and demands further investigation. First author Che-Jung Chang noted that PFAS exposure is potentially modifiable. NIH said PFOA and PFOS have been largely phased out and replaced with new PFAS compounds, and that more research is needed on the replacements.
(Source: National Institutes of Health)
来源：美国国立卫生研究院
发布：GSM·美国（发布链接）
图片来源：图：位于 Bethesda 的美国国立卫生研究院临床中心（10号楼）。NIH Image Gallery 摄，公共领域，经 Wikimedia Commons。 / Photo: The NIH Clinical Center (Building 10) in Bethesda, Maryland. Photo by NIH Image Gallery, public domain, via Wikimedia Commons.
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