En español | In the continuing debate over whether or not regular mammograms help prevent breast cancer deaths, the pro-screening camp has some powerful new ammunition: A new Dutch study shows that women who participated in at least three screening mammograms had a nearly 50 percent lower risk of dying from breast cancer.
In addition, the study presented strong evidence that mammograms help detect tumors in their early stages, thereby increasing a woman's odds of survival.
Dutch researchers reported that advanced (stage 4) tumors were found in 30 percent of women who had never been screened before they were diagnosed, but only in 5 percent of women whose cancer was detected during screening.
"Our study adds further evidence that mammography screening unambiguously reduces breast cancer mortality," said senior researcher Suzie Otto with the department of public health at Rotterdam's University Medical Center.
"It reaffirms what most clinicians in the U.S. have been saying all along. Women should be regularly screened," says William Gradishar, M.D., a breast cancer expert with the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, who was not part of the study.
Robert Smith, director of cancer screening at the American Cancer Society, called the Dutch study "a very careful analysis" that has produced results similar to several recent large international studies in Sweden, Denmark, Italy and Australia.
"All of these studies show that women who are not screened, their rates of advanced disease is much higher," Smith says. "Mammography allows a woman to begin treatment when her prognosis is going to be much better."
The Dutch study, published this week in the journal Cancer Epidemiology, Biomarkers & Prevention, was the largest of its kind in the Netherlands, which began a nationwide screening program in 1989 for women 50 and older.
The researchers looked at 8,369 women over age 50 with breast cancer, including 755 patients who died from the disease between 1995 and 2003.