乳腺癌发病率正在上升。塑料和化妆品是罪魁祸首吗？

【中美创新时报2024 年 10 月3 日编译讯】（记者温友平编译）根据美国癌症协会周二发布的一份新报告，2012 年至 2021 年间，患乳腺癌的风险每年增加约 1%，50 岁以下女性的增长速度几乎是 50 岁以上女性的两倍。《波士顿环球报》记者Adam Piore对此作了下述报道。

但这份两年一度的报告确实包含了一些希望，被称为近年来发布的最详细的乳腺癌发病情况快照之一。由于筛查技术和治疗方法的进步，1989 年至 2022 年间，死于乳腺癌的人数下降了 44%。马萨诸塞州的乳腺癌死亡率是全美最低的，大多数专家将此归因于高筛查率和强大的医疗基础设施等因素。

根据周二的研究，在所涵盖的九年期间，50 岁以下女性的乳腺癌发病率每年增长 1.4%，而 50 岁以上女性的乳腺癌发病率约为 0.7%。该研究基于美国国家癌症研究所和疾病控制与预防中心的数据。

但这种疾病在年轻女性中仍然很少见。30 岁时被诊断出患有乳腺癌的 10 年概率为 1/198，即 0.5%，而 40 岁时被诊断出患有乳腺癌的概率为 1/62，即 1.6%，50 岁时被诊断出患有乳腺癌的概率为 1/41，即 2.5%。

种族之间也存在显著差异。亚裔美国人/太平洋岛民女性在两个年龄组中的增幅最快（50 岁以下女性每年 2.7%，50 岁以上女性每年 2.5%）。但对于黑人女性来说，乳腺癌是头号杀手，她们患乳腺癌的可能性比白人女性低 5%，但死于乳腺癌的可能性却高出 38%。

为什么年轻女性的乳腺癌发病率在上升？

专家们没有明确的答案，但有很多理论。一些人指出肥胖症流行可能是原因之一。麻省大学纪念医学中心和 HealthAlliance-Clinton 医院的肿瘤学家 A. Gwen Caffrey 博士说，高体重指数与月经初潮早有关，这是患乳腺癌的一个风险因素。她还指出，酒精是致癌物，并指出“精酿啤酒文化”的兴起和其他影响年轻人饮酒量的因素。

丹娜—法伯癌症研究所乳腺肿瘤中心的医学肿瘤学家和临床研究员 Harold J. Burstein 博士指出，女性生育的孩子越来越少，生育年龄越来越大，哺乳时间也越来越少，所有这些都可能增加乳腺癌的人口风险。

丹娜法伯癌症研究所年轻乳腺癌项目创始人兼主任安·帕特里奇博士表示，无论原因是什么，都迫切需要资助研究以查明原因。她说，被诊断出患有乳腺癌的年轻女性往往会患上更具侵袭性的癌症，这往往需要更积极的治疗方法。

“即便如此，她们的平均表现也比患有相同疾病的老年女性更差，”她说。

女性可以做些什么来降低患病风险？

专家表示，戒烟、健康饮食和远离酒精可以降低患病风险，定期锻炼也可以。

早期筛查和了解家庭风险也可以发挥重要作用。今年 4 月，美国预防服务工作组（由美国卫生与公众服务部资助的独立专家小组）将定期乳房 X 线检查的建议年龄从 50 岁降低到 40 岁。

但有乳腺癌家族史的女性可以接受遗传咨询，并在更早的年龄开始进行乳房 X 线检查或其他影像学检查，以增加早期发现的机会。

帕特里奇说，丹娜法伯癌症研究所有一个名为“评估您的风险”的在线工具，这是一个不错的起点。

对于高风险患者，有些药物可以显著降低某些乳腺癌的风险。这些药物包括每天服用一次的药丸他莫昔芬，服用三到五年后，可将乳腺癌风险降低约一半，卡弗里说。

如果你太年轻而不能做乳房 X 线检查，你如何提高早期发现的几率？

帕特里奇说，年轻女性需要“提出问题并成为自己最好的倡导者”。

“因为虽然年轻女性的乳腺癌发病率正在上升，但仍然很罕见，但确实会发生，”她说。“不应该对任何女性说‘你太年轻了，不会得乳腺癌，我们只是要观察一下那个肿块。’我们需要真正教育女性和医疗服务提供者，确保人们在出现乳腺癌症状或体征时得到所需的护理。”

所有年龄段的女性也应该了解自己的乳房，这样她们才能迅速注意到变化。

“这不仅仅是乳房自我检查的概念，”卡弗里说。“你应该知道，一个乳房是否比另一个大？你是乳房有肿块还是没有肿块？你的乳头是内陷还是外翻？这些都是正常现象，每个人的身体都有正常差异。但当你意识到自己的乳房是什么样子时，你就更能识别出变化了。”

她说，与乳腺癌相关的最常见变化是硬的、无痛的肿块，它不会随月经周期波动，不会自行消失，只是继续生长。其他需要注意的变化包括大小变化、对称性变化、乳头形状变化、乳房轮廓、新的乳房肿胀以及异常或血性乳头分泌物。

“这些都是不应该等到例行就诊或常规筛查研究才发现的问题，”她说。“这些都是立即联系医生进行检查的理由。”

你应该对食用塑料或阅读化妆品成分以避免毒素有多担心？

几位临床医生表示，这是一个“热门话题”，但指出目前尚无定论。

“目前并没有太多确凿的数据表明止汗剂、护发产品、化妆品或面部产品会影响乳腺癌的风险，”伯斯坦说。“我认为女性可以随意使用这些产品，而不必过分担心。”

那么乳房组织致密的女性呢？

据估计，几乎一半的美国女性乳房组织致密，这使得乳房 X 线摄影检查异常更加困难，并且与患乳腺癌的风险增加有关。本月早些时候，美国食品和药物管理局实施了一项新规定，要求乳房 X 线摄影机构通知乳房组织致密的女性，以便她们可以考虑进行额外的影像学检查。

Caffrey 表示，乳房组织致密的女性应继续进行年度乳房 X 线摄影检查。但她们还应考虑补充影像学检查，包括超声波和核磁共振成像，这些检查通常由高风险女性的保险承保。

Partridge 还经常建议乳房组织致密的患者进行额外的影像学检查，而她治疗的年轻患者中，这种情况更为常见。不过她指出，这样做也有缺点：由于扫描非常详细，因此更有可能出现假阳性，需要进行后续扫描，甚至活检。

题图：50 岁以下女性中乳腺癌仍然很少见，但发病率正在上升。Sarah Reingewirtz/MediaNews Group/洛杉矶每日新闻/通过盖蒂图片社

附原英文报道：

Breast cancer rates are climbing. Are plastics and cosmetics to blame?

Experts weigh in on how to lower your risk

By Adam Piore Globe Staff,Updated October 2, 2024

Breast cancer is still rare in women younger than 50, but rates are going up.Sarah Reingewirtz/MediaNews Group/Los Angeles Daily News/via Getty Images

The risk of developing breast cancer increased by about 1 percent each year between 2012 and 2021 and grew almost twice as fast for women under the age of 50 as those above it, according to a new report published Tuesday by the American Cancer Society.

But the biennial report, billed as one of the most detailed snapshots of breast cancer occurrence to be published in recent years, did contain some silver linings. Deaths from the disease fell by 44 percent between 1989 and 2022, thanks to advances in screening techniques and treatments. And Massachusetts had the lowest rate of breast cancer mortality in the nation, an outcome most experts attribute to high rates of screening and a robust medical infrastructure, among other factors.

Breast cancer rates grew at 1.4 percent annually for women under 50 in the nine-year period covered, compared to roughly .7 percent for those over 50, according to Tuesday’s study, which was based on data from the National Cancer Institute and the Centers for Disease Control and Prevention.

But the disease remains rare in younger women. The 10-year probability of being diagnosed with breast cancer at 30 is 1 in 198, or 0.5 percent, compared with 1 in 62, or 1.6 percent, at age 40, and 1 in 41, or 2.5 percent, at 50.

There were also significant disparities by race. Asian American/Pacific Islander women had the fastest increase in both age groups (2.7 percent per year for women younger than 50 and 2.5 percent per year for those over 50). But it is the top killer for Black women, who are 5 percent less likely to get breast cancer than white women but have a 38 percent higher chance of dying from it.

Why is the incidence of breast cancer rising among young women?

Experts don’t have clear answers, but there are plenty of theories. Several pointed to the obesity epidemic as a possible cause. Dr. A. Gwen Caffrey, an oncologist at UMass Memorial Medical Center and HealthAlliance-Clinton Hospital, said high body mass index is associated with early menarche, which is a risk factor in developing breast cancer. She also noted that alcohol is carcinogenic and pointed to the rise of “craft beer culture” and other factors that influence the amount of alcohol consumed by young people.

Dr. Harold J. Burstein, a medical oncologist and clinical investigator at the Dana-Farber Cancer Institute’s Breast Oncology Center, noted that women are having fewer children, having them at later ages, and spending less time nursing, all of which could increase the risk of breast cancer on a population level.

Whatever the cause, there is an urgent need to fund the research needed to figure it out, said Dr. Ann Partridge, founder and director of the program for young adults with breast cancer at Dana-Farber. Younger women who are diagnosed with breast cancer, she said, tend to get more aggressive types of cancer, which often require more aggressive therapies.

“And even with that, they on average do worse than older women with the same disease,” she said.

What can women do to lower their risk?

Smoking cessation, a healthy diet, and steering clear of alcohol can reduce risk, as can regular exercise, experts said.

Early screening and an understanding of familial risk can also make a big difference. In April, the US Preventive Services Task Force, an independent panel of experts funded by the US Department of Health and Human Services, lowered the recommended age for regular mammography screening from 50 to 40.

But women with a significant family history of breast cancer can get genetic counseling and start mammograms or other imaging tests at even earlier ages to increase the chances of early detection.

Dana-Farber has an online tool called Assess Your Risk that is a good place to start, said Partridge.

For high-risk patients, there are medications that can significantly reduce the risk of some breast cancers. Those include a once-a-day pill, Tamoxifen, that when taken for three to five years, may reduce the risk of breast cancer by roughly half, Caffrey said.

If you’re too young for a mammogram, how can you improve your odds of early detection?

Young women need to “ask questions and be their own best advocates,” said Partridge.

“Because while breast cancer in young women is increasing, it’s still rare, but it does happen,” she said. “No woman should be told, ‘You’re too young to get breast cancer, we’re just going to watch that lump.’ We need to really educate women and providers on how to make sure that people are getting the care they need should they develop symptoms or signs of a breast cancer.”

Women of all ages should also get to know their own breasts so they can quickly notice changes.

“That goes beyond just the idea of a breast self-exam,” Caffrey said. “You should know, is one breast larger than the other? Are you somebody with lumpy breasts or not lumpy breasts? Are your nipples inverted or everted? Those are all normal things and normal variations from one person’s body to another. But when you are aware of what your breasts look like, you’re that much more able to identify a change.”

The most common change associated with breast cancer, she said, is a hard, painless lump that doesn’t fluctuate with menstrual cycles, doesn’t go away on its own and just continues to grow. Other changes to be on the lookout for are changes in size, changes in symmetry, changes in the shape of the nipple, the contour of the breast, new breast swelling, and unusual or bloody nipple discharge.

“Those would all be things that should not wait for a routine visit or routine screening study,” she said. “Those would be reasons to reach out to your doctor to be looked at right away.”

How much should you worry about consuming plastic or reading makeup ingredients to avoid toxins?

Several clinicians said that is a “hot topic” but noted the jury is still out.

“There’s really not a lot of hard data that antiperspirant, hair products, makeup, or facial products affect the risk of breast cancer,” said Burstein. “I think women can use those products as they wish without undue concern.”

What about women with dense breast tissue?

By some estimates nearly half of all American woman have dense breasts, which makes it harder to detect abnormalities on mammograms and is associated with a greater risk of developing breast cancer. Earlier this month, the Food and Drug Administration implemented a new rule requiring mammography facilities to notify women if they have dense breasts, so that they can consider additional imaging tests.

Women with dense breasts should continue with their annual mammogram, Caffrey said. But they should also consider supplemental imaging options, including ultrasounds, and MRIs, which are often covered by insurance for women at higher risk.

Partridge also often advises patients with dense breast tissue, which is far more common in the younger patients she treats, to undergo additional imaging. Though she notes there are drawbacks: Because the scans are so detailed, they are far more likely to have false positives that require follow-up scans, and even biopsies.