Women who wait at least 15 years after their first menstrual period to give birth to their first child may reduce their risk of triple-negative breast cancer by up to 60 percent, according to a Fred Hutchinson Cancer Research Center study. The research also showed that breast-feeding can reduce the risk of triple-negative. The findings are published online in Breast Cancer Research and Treatment.
“Breast-feeding is emerging as a potentially strong protective factor” against TNBC, said Christopher I. Li, M.D., Ph.D., lead researcher.
[Pat’s note: I breast fed both my children, but my oldest was born about 14 years after I started menstruating, so that part is intriguing. Glad my daughter was older when she had her boys.]
The study may have particular implications for some African-American women, who are disproportionately affected by TNBC but who, as a group, are more likely to start having children at a younger age and are less likely to breast-feed, Li said.
“Our observations that delayed childbearing and breast-feeding are protective against triple-negative breast cancer suggest that variations in reproductive histories by race may to some extent explain the higher rates of triple-negative disease in African-American women,” Li said.
Researchers studied more than 1,960 Seattle-area women between the ages of 20 and 44, 1,021 with a history of breast cancer and 941 without.
“This is an observational study and also one of the first to focus on premenopausal breast cancer and so our results require confirmation and thus should be interpreted with some caution,” Li said.
Source: “Reproductive factors and risk of estrogen receptor positive, triple-negative, and HER2-neu overexpressing breast cancer among women 20-44 years of age,” Breast Cancer Research and Treatment.