Breastfeeding protects women with cancer gene

BREASTFEEDING dramatically protects young women with inherited breast cancer genes from developing the disease, a study has found.

Breast cancer is the second most common cancer in Ireland after skin cancer.

Irish statistics show that breast cancer accounts for 28% of all cancers in women in Ireland, with an average of 1,726 new diagnoses each year.

Researchers said mothers with a family history of breast cancer were 59% less likely to develop tumours before the menopause if they breastfed their children.

The effect is significant because women with the two most important breast cancer genes, BRCA-1 and BRCA-2, have a 50% to 80% chance of getting breast cancer in their lifetime.

Inherited breast cancer is also much more likely to strike younger women.

An average woman aged 30 has a one in about 2,500 chance of developing breast cancer. But if she has one of the two BRCA genes the odds are one in three.

The latest US research suggests that a young mother can more than halve that risk simply by breastfeeding.

In fact, the protective effect was similar to that of taking the gold-standard hormonal treatment Tamoxifen for five years.

“This is good news for women with a family history of breast cancer,” said Dr Alison Stuebe, from the University of North Carolina, who led the study reported in the Archives of Internal Medicine.

The researchers reviewed data from the Nurses’ Health Study II, a long-term investigation of more than 100,000 women from 14 US states.

Comparing outcomes between different groups revealed the reduced risk of inherited breast cancer for breastfeeding mothers.

Why breastfeeding reduces the risk of breast cancer is unknown. One possibility might be that when women do not breastfeed, inflammation and swollen tissue cause changes after giving birth that fuel the growth of tumours, the scientists believe.