Breastfeeding Can Reduce Risk of Breast Cancer Returning: Study

Women with breast cancer who breastfed their babies are significantly less at risk of the disease recurring or killing them, a study has found.

According to a new Kaiser Permanente study of hundreds of Northern California women also found that breastfeeding cuts the likelihood of the disease coming back by 30 percent. Scientists believe that the protective effect is caused by a reduction in the levels of the hormone oestrogen, which is known to trigger cancer.

Lead researcher Dr Marilyn Kwan said: "This is the first study we're aware of that examined the role of breastfeeding history in cancer recurrence, and by tumour subtype.

"Women who breastfeed are more likely to get the luminal A subtype of breast cancer, which is less aggressive, and breastfeeding may set up a molecular environment that makes the tumour more responsive to anti-oestrogen therapy."

The study, published Tuesday in the Journal of the National Cancer Institute, builds on previous evidence that shows breastfeeding appears to have a protective effect against breast cancer. The study looked at data from 1,636 women with breast cancer who completed a questionnaire about breastfeeding.

Co-author Dr Bette Caan, also from Kaiser Permanente, said: "Breastfeeding may increase the maturation of ductal cells in the breast, making them less susceptible to carcinogens or facilitate the excretion of carcinogens, and lead to slower growing tumors."

Numerous studies have shown that breastfeeding has many health benefits for mother and baby, aside from protecting against cancer.

It has been shown to prevent breast cancer by between ten and 20 per cent and a study last year found it was particularly beneficial for one of the most deadliest types of tumors.