Mammograms Benefit Younger Women
Reduce Risk of More Aggressive Breast Cancer
In their study, they followed 247 premenopausal women who were diagnosed with breast cancer during the course of the six-year trial. Half had had at least one mammogram within two years before the study began, while the others had no screenings.
About 40% of the screened women were later found to have later-stage tumors, compared with 52% of the unscreened women. After accounting for other factors that affect breast cancer risk, such as family history or estrogen use, the researchers determined that women in their 40s who get regular mammograms are 44% less likely to develop an aggressive breast cancer. This benefit would likely translate into decreased deaths from breast cancer among women in their 40s, say the researchers.
Although most health agencies recommend mammograms annually or every two years starting at age 40, in practice, many physicians seem to stress their importance after age 50, when breast cancer is even more common. As a result, about 70% of women in their 40s get mammograms, says Byers. Barriers -- both from the patient and the doctor perspective -- include cost, convenience, and denial, he says. In addition, there is worry about false positive tests -- when a mammogram is thought to indicate breast cancer at first but is later found to be normal with further testing.
Another reason: Most previous studies have shown little or no benefit from screenings in pre-menopausal women. But that's because they looked at long-term survival after breast cancer as opposed to the stage at which breast cancer is diagnosed. Even though it makes sense that diagnosing breast cancer earlier would improve survival, research at this point has been unable to establish this for women in their 40s.
"But when you look at survival as the end point, rather than actual breast cancer events, you're really not getting the accurate picture on the benefits of mammogram for this age group," says Ruth Heimann, MD, PhD, a cancer researcher at the University of Chicago who was not involved in this study. "What happens is that after age 50, [heart] disease becomes the leading cause of death in women and a majority of women with early-stage breast cancer ultimately die from heart disease -- and not from the breast cancer itself.