Study: Breast Cancer in New Mothers Tends to Be More Aggressive

Women diagnosed with breast cancer within 2 years of giving birth tend to have a more aggressive form of the disease, according to researchers at the Fred Hutchinson Cancer Research Center in Seattle, Washington.

Researchers followed up on 1,174 women with breast cancer who were diagnosed before age 45. They collected samples of ductal tumors from 79 percent of the women.

Women who had given birth within 2 years prior to diagnosis had more than double the risk of dying of their disease, compared with women who had given birth 5 or more years before, or women who have not had children, said Janet Daling, co-author of the study.

"The tumors of these women have markers of aggressiveness," she said. These markers include lymph node involvement, a high histological stage, as well as others, according to the study published in The Lancet.

The time since childbirth had an additional effect on the women's mortality rate that was independent of the tumor markers and treatment, indicating that the link between childbirth and breast cancer severity is yet to be solved.

Researchers speculate that high hormone concentrations during pregnancy may play a role in the time since childbirth and breast cancer aggressiveness association.

Investigators caution that recent childbirth is not an indication for aggressive breast cancer therapy and physicians should first look for tumor markers showing an aggressive cancer. Women with tumor markers showing aggressive cancer should then receive more aggressive therapy.

Other Sources: The Lancet