Mammogram's Benefit During 40s Still Uncertain
British study weighed plusses, minuses for nearly 161,000 women tracked over 11 years
FRIDAY, Dec. 8, 2006 (HealthDay News) -- It's still unclear whether the benefits of routine annual mammograms for women aged 40-49 outweigh the risks, according to British researchers.
A team at the Institute of Cancer Research in London tracked 160,900 participants for an average of 11 years. The women were divided into two groups: Women in the study group were offered annual mammography screenings beginning at age 40, while those in the control group were offered annual screenings beginning at age 50.
Breast cancer deaths among the younger women decreased by 17 percent compared with the control group, but this figure was not statistically significant, the researchers said.
The study also found that of the women who did get regular screenings, 23 percent of the younger women had at least one false-positive result (an aberration that later turned out not to be breast cancer), compared with 12 percent of older women.
Other possible harmful effects of regular screening include the risk of radiation-induced breast cancer, the study authors noted. However, they said that this risk would outweigh the benefit in only a small percentage of women.
The study is published in this week's issue of The Lancet.
Benjamin Djulbegovic, of the H. Lee Moffitt Cancer Center and Research Institute in Tampa, Fla., wrote an accompanying comment to the study.
In a prepared statement, he said: "the decision of whether to recommend screening mammography crucially depends on estimates of harm, which will never be zero."
"Although the best estimates of harms from screening mammography seem to be less than the benefits, they remain too uncertain to conclude that screening mammography in this age-group is associated with a net benefit," he noted.
"Benefit and harms need to be contrasted with each woman's individual risks for development of breast cancer," Djulbegovic concluded. "Every woman, with her physician's guidance, should decide whether regret will be greater if she develops breast cancer that could have been detected earlier by screening mammography, or if she develops breast cancer later in life as a result of screening mammography itself."
The U.S. National Cancer Institute has more about breast cancer screening.