(ChemothapyAdvisor) – Results of a mammography screening program, ongoing since 1990 in the Netherlands, has shown that screening coincides with fewer breast cancer deaths, limited harms, and reasonable costs, according to a study presented at the annual European Breast Cancer Conference, held from March 21 to 24 in Vienna.
Jacques Fracheboud, MD, from the Erasmus University Medical Center in Rotterdam, Netherlands, and colleagues examined outcomes and costs of a mammography breast cancer screening program in the Netherlands from 1990 to 2009.
The researchers found that 16.6 million invitations were sent to 3.6 million women during the study period. Attendance increased from 73.5% in 1990 to 81.5% in 2009. Of the 13.2 million exams performed for 2.9 million women, 1.35% received referrals, 0.72% underwent needle or open biopsies, and 0.50% were diagnosed with breast cancer. Up to 2005, the program sensitivity was about 70% and the specificity was about 99%. The mean annual total cost was €32.6 million, and the mean cost per examination was €49.39. Breast cancer mortality fell by 31.3% in 2009 compared with the prescreening period. Mortality increased annually by 0.3% before the screening program and fell by 1.7% annually after the program, which coincided with fewer cancers detected at an advanced stage. Over-diagnosis occurred in 8.9% of cancers detected by screening and in 2.8% of cancers overall.
“These results provide convincing evidence that the program contributed to the breast cancer mortality decrease that has been observed in the last 20 years in the Netherlands, and that harms such as the false-positive rates, the interval cancer rate — cancers that are diagnosed in the interval between screenings — and the proportion of over-diagnosed breast cancers were quite limited,” Fracheboud said in a statement. “Our study also shows that the program is of a high quality and is continually improving. It has a high acceptance rate among women aged 50 to 75 and the costs of the program are reasonable.”