A new report suggests that breast-feeding, which has been associated with a reduced breast cancer risk, may have another benefit. In mothers who later develop breast cancer, breast-feeding may reduce the risk of cancer recurrence¹.

一份新的报告显示，哺乳除了与较低的乳腺癌风险相关之外，可能还具有另一个好处。在后来罹患乳腺癌的母亲中，哺乳或可降低癌症复发的风险。

The study, in the July issue of The Journal of the National Cancer Institute, followed 1,636 breast cancer survivors². Researchers examined medical records and gathered data on whether mothers had ever breast-fed their children. They found 383 recurrences³ and 290 breast cancer deaths during an average nine years of follow-up after completion of treatment.

该研究发表在7月号的《国家癌症研究所杂志》(Journal of the National Cancer Institute)上，共计随访了1636名乳腺癌幸存者。研究人员审查了她们的医疗记录，并收集了关于其哺乳史的数据。他们发现，在治疗结束后的随访期间（中位时间为九年），出现了383例复发，290人因乳腺癌死亡。

After controlling for age, smoking, education, race, type of therapy and other factors, they found that compared with women who had never breast-fed, any breast-feeding was associated with a 30 percent reduced risk of recurrence, and breast-feeding for more than six months was associated with a 37 percent reduced risk. There were similar risk reductions for breast cancer deaths.

在对年龄、吸烟史、教育状况、种族、接受治疗的类型和其他因素进行校正后，研究人员发现，与从未哺乳过的女性相比，哺乳史与复发风险降低30%相关，哺乳期超过六个月与复发风险降低37%相关。在因乳腺癌死亡的风险方面也可见类似的降低。

“Breast-feeding is a good thing for the baby, and there are additional benefits for the mom that this study suggests,” said the lead author, Marilyn L. Kwan, a research scientist at Kaiser Permanente in Oakland, Calif. “This contributes to information already available in making a personal decision about whether or not to breast-feed.”

“母乳喂养对婴儿有益，而该研究表明此举也能给母亲带来额外的好处，”该研究的主要作者，凯萨医疗机构（Kaiser Permanente，位于加利福尼亚州奥克兰市）的科学家玛丽莲·L·关(Marilyn L. Kwan)说。“这一研究结果为母亲决策自己是否要进行哺乳提供了更多有益的信息。”

The risk reductions were particularly apparent in estrogen-receptor positive cancers, the most common type, but were not significant for women with HER2 positive tumors. Breast-feeding leads to certain molecular⁴ changes in breast cells, which may help explain the effect.

这种风险的降低在最常见的一类乳腺癌——雌激素受体阳性癌症中尤其明显，但在HER2（人类表皮生长因子受体2）阳性肿瘤患者中并不显著。哺乳可引起乳腺细胞中的一些特定的分子改变，这可能有助于解释上述影响。