Women who participated in at least three mammogram screenings had a 49% lower risk for breast cancer mortality, according to a case-control study.
“Our study adds further evidence that mammography screening unambiguously reduces breast cancer mortality,” Susie Otto, PhD, a senior researcher in the department of health at the Erasmus MC at Rotterdam in the Netherlands, said in a news release.
Otto and colleagues observed 755 patients who died from breast cancer from 1995 to 2003 and matched them with 3,739 controls. Among the breast cancer cases, 29.8% were detected at screening, 34.3% were detected between screenings and 35.9% had never been screened.
Stage IV tumors were present in 29.5% of the never-screened cases but only 5.3% of the screen-detected cases.
If women attended at least three screenings prior to diagnosis, their risk for mortality from breast cancer decreased by 49%. The greatest reduction was seen in women ages 70 to 75, for whom the reduction in mortality was 84%. Among younger women (ages 50 to 69), the reduction was smaller, at 39%, but still statistically significant.
Otto said the findings could be applicable in the United States in principle, but the U.S. lacks a centrally organized government-funded program for mammograms similar to what is found in the Netherlands.
“The Dutch government considers it imperative that everyone eligible for a screening program is given the opportunity to participate,” Otto said. “For that reason, all women in the targeted age group are invited and given the opportunity to decide independently to participate or not in screening programs that are entirely free of charge.”
The study appears in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research. To read a summary and access the study via subscription or purchase, visit http://bit.ly/tIH2Y1.