Attention all breastfeeding moms, including those of you who are young and have no family history of breast cancer. While you may be correct in assuming that the appearance of a breast lump in a breastfeeding mom is most likely a plugged duct, any lump that doesn’t go away within 2-3 days needs to be evaluated.

A recent article published 11 August 2008 in Mail Online highlights why this is so important.

Jayne Gross, a breastfeeding mother of three young sons, dismissed the lump she found in her breast when her youngest son was only three months old. “It hadn’t occurred to me that it could be anything sinister,” said Gross. She assumed (incorrectly) that it was a plugged milk duct, and three months passed before she had the lump examined. “I thought that because I was breastfeeding, I was somehow safe,” said Gross.

After being diagnosed with breast cancer, Gross underwent a double mastectomy, followed by four months of chemotherapy and one year of Herceptin therapy. Herceptin is a drug that attaches itself to the surface of cancer cells and prevents them from growing. The good news is that two and one-half years later, Gross shows no signs of cancer.

Breastfeeding and breast cancer
Excluding skin cancer, breast cancer is the most common cancer among women. The risk for breast cancer increases with age. During 2000-2004, ninety-five percent of new breast cancer cases and ninety-seven percent of breast cancer deaths occurred in women 40 years of age and older. At the same time, pregnancy rates for women 30 years of age and over have been increasing modestly since the mid-1990s. Today, more women in their 40s are having babies, which may explain in part the growing number of women diagnosed with breast cancer while pregnant or breastfeeding.

The role of breastfeeding in reducing breast cancer risk was detailed in a study published in The Lancet in 2002. Researchers analyzed individual data from 47 epidemiological studies in 30 countries, including 50,302 women with breast cancer and 96,973 women without the disease. When women who never breastfed were compared to those who breastfed, a woman’s risk for breast cancer decreased by 4.3 percent for each year of breastfeeding and by 7 percent for each birth.

The latest study, conducted by researchers at the Fred Hutchinson Cancer Research Center in Seattle, involved 2616 women ages 55 to 79 years—1140 with breast cancer and 1476 without. Breastfeeding for at least six months was associated with a lower risk for triple negative breast cancer, a highly aggressive form of breast cancer that does not respond to traditional treatments with regulatory proteins or hormones. The results, which will be published in the October 2008 issue of the journal Cancer, do not prove that breastfeeding helps prevent breast cancer, only that there is an association between the two.

In the meantime, there is ample upside (and no downside) to breastfeeding for longer periods of time. Just make sure that any lump detected during that period isn’t ignored.