Mother’s Age May Impact Breast Cancer Risks

Triple negative breast cancer more common in younger mothers

(RxWiki News) Younger women are more prone to what’s known as triple-negative breast cancer. There aren’t any good treatments for this very bad cancer. Delaying childbirth and breastfeeding, though, may be ways to ward it off.

New research suggests that a woman can reduce her risks of triple-negative breast cancer by waiting to have her first child at least 15 years from the time her periods started. So, if she was 11 when she began menstruating, the woman would wait until she’s 26 to have her first child.

This strategy, along with breastfeeding, may provide some protection against triple-negative breast cancer.

These findings could be particularly meaningful for black women, who are more likely to develop triple-negative disease than are white women. The lead investigator cautions that these findings need to be confirmed with further study.

"If possible - breastfeed your babies."

Christopher I. Li, MD, PhD, a member of the Public Health Sciences Division at Fred Hutchinson Cancer Research Center, led the study. Participants included 1,960 women between the ages of 20 and 44, 1,021 who had a history of breast cancer and 941 who had no history.

"We found that the interval between menarche [first menstrual period] and age at first live birth is inversely associated with the risk of triple-negative breast cancer," Li said in a statement.

Hormone-blocking therapies like tamoxifen don’t touch types of cancer that don't have genes for estrogen receptor (ER), progesterone receptor (PR) or HER2/neu. The triple-negative subtype, which is seen most often in black women, accounts for 10-15 percent of the 229,000 breast cancers diagnosed every year in America.

This is the first study to look at the timing of childbirth and risks of triple-negative breast cancer. Previous studies have found that breastfeeding does lower a woman’s risk of this tough-to-beat type.

According to Dr. Li, delaying childbirth for 15 years and breastfeeding once she does give birth may help a woman reduce her risks. Breastfeeding also helps to lower the risks of the most common form of breast cancer – ER positive.

These results may be particularly important for black women who see triple-negative cancers far more frequently than white women do. While the precise reasons for this are not known, statistics show that black women tend to start having babies at younger ages and tend not to breastfeed their children.

"Our observations that delayed childbearing and breastfeeding 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.

He added that these results need to be confirmed, so these findings should be interpreted with caution.

This research was published in the December issue of Breast Cancer Research and Treatment. This study was funded by the National Cancer Institute and the Department of Defense Breast Cancer Research Program. No conflicts of interest were disclosed.

Review Date: 
December 16, 2012