乳腺癌患者不适合食用过量大豆豆浆–富含大豆饮食可能促进乳腺肿瘤生长

乳腺癌

最近公布的一项随机研究显示,在激素受体阳性乳腺癌患者中,摄入豆制蛋白可能增强肿瘤有关增殖基因的表达。

美国纽约纪念医院肿瘤中心的MOSHE教授指出,根据流行病学研究结果报道,许多女性认为摄入大量的豆制品可能抑制乳腺癌细胞的增长。亚洲人群的一些研究发现,豆制品的摄入与乳腺癌发病风险降低有关,但是这些研究并不能证明豆制品具有保护作用,只能确认两者具有相关性。

这项针对确诊乳腺癌患者的新研究发现,豆类中含有植物雌激素,这一物质可能模仿雌激素样作用,至少是起到微弱的作用,而在确诊乳腺癌后雌激素并不是一件好事。

SHIKE教授等研究了早期乳腺癌诊断时活检所得到癌细胞和稍后肿瘤手术切除后的乳腺癌细胞分子构象的变化。140例女性参加这项随机研究,分成两组,分别在每天同一时间内摄入豆类蛋白或者牛奶蛋白,25.8G袋装,混入水或者果汁中后饮用。与服用牛奶组相比,摄入豆类蛋白组的肿瘤细胞过表达细胞周期和细胞增殖相关基因。在一些豆类蛋白质中,有一肿瘤生长相关基因的表达增高,这一研究仅仅是在基因层面探索肿瘤细胞变化,而并非是每例患者肿瘤生长或不生长的变化,并无法确认这些患者对豆类蛋白的特殊反应。该研究所能得到的结论是:一些患者中,在基因水平上,豆类成分可能驱动增殖基因,但这些将会导致肿瘤的何种转归还不清楚。

该文作者推荐适度食用,认为摄入过量的豆制品可能不合理,但尚无临床证据,因为这些研究仅仅是在基因表达上进行探讨。在针对该研究的论述中,JORDAN教授指出:在女性一生中,雌激素对于乳腺癌具有不同的作用,与月经状态也有很大关系。对患有乳腺癌的女性,豆制品并不是好东西。—摘自:J NATL CANCER INST.2014年9月4日在线版。

原文如下,供大家参考:

High-Soy Diet May Drive Breast Tumor Growth: Study
NEW YORK (Reuters Health) – In women with estrogen-receptor positive breast cancer, taking soy protein supplements boosted the expression of tumor genes associated with cell proliferation, in a recent randomized trial.
Many women take tremendous amounts of soy thinking it will prevent breast cancer based on epidemiological studies, said lead author Dr. Moshe Shike of Memorial Sloane Kettering Cancer Center in New York.
Some studies of Asian populations have found that as soy intake increased, breast cancer risk decreased, but those studies couldn’t prove a benefit of soy – they could only identify an association, Shike said.
The new study, however, looked at women who had already been diagnosed with breast cancer.
Soybeans contain phytoestrogens, which can mimic, at least weakly, some effects of the hormone estrogen – and “estrogen is no good at any time after breast cancer diagnosis,” said V. Craig Jordan of the Georgetown University Lombardi Comprehensive Cancer Center in Washington, D.C., in a phone interview. Jordan’s editorial was published with the paper online September 4 in the Journal of the National Cancer Institute.
With support from the Breast Cancer Research Foundation, Shike and his coauthors studied changes in the molecular structure of early-stage breast cancer cells obtained from biopsies done at diagnosis and again few weeks later, when the tumor was removed.
The 140 women in the study were randomly assigned to take either soy protein or milk protein supplements in the meantime, in the form of two 25.8 gram packets mixed into water or juice each day.
Compared to tumors in the milk group, the tumors in the soy group were overexpressing genes associated with the cell cycle and cell proliferation.
For some in the soy group, expression of a gene associated with cancer growth increased, too, the authors reported.
The study only looked at tumor changes on a genetic level – not at how tumors grew or didn’t grow in each individual woman.
It’s not clear what made those women in particular respond to soy protein, Shike told Reuters Health by phone.
“All we can say is that in some of the women, the soy component drove proliferative genes, at the gene level,” he said. “How it would translate into cancer outcome we can’t say.”
“What we recommend is moderation, meaning we think that taking excessive amounts of soy may not be a good idea,” Shike said. “We don’t have clinical proof for that because this is only gene expression.”
In the editorial, Jordan suggests that estrogen may have different effects on breast cancer based on a woman’s stage of life, whether she is in menopause or after menopause has ended.
“For populations of women with breast cancer, soy products aren’t good,” Jordan said. “Now doctors have a set practice and can tell patients that this isn’t a good thing.”

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