According to a new study, mammography scans are offering less than expected reduction of mortalities caused by breast cancer. The study took place in Norway, and its findings are highlighted in the New England Journal of Medicine. The study continues the ongoing international debate questioning the effectiveness of conducting mammography screening programs.
Dr. Mette Kalager and her team from the Oslo University Hospital said that performing mammography scans along with providing improved healthcare, including cancer therapy, for women at the age of 50 to 69 resulted in reducing breast cancer mortalities by 10%. However, when improved healthcare service was offered to women older than 70 without using mammography, mortalities were reduced by 8%. The previous findings indicated that mammography had a limited effect in cutting mortalities of breast cancer. Dr. Kalager said, "There is a reduction in mortality, but it's lower than we anticipated," She added that the expected reduction using mammography was 30%. The study involved reviewing data coming from 40,075 women. On the other hand, Dr. Gilbert Welch, from New Hampshire's Dartmouth Medical School, wrote commenting on the study, in the New England Journal of Medicine, that mammography screening reduced breast cancer mortalities by only 2%. He added that for every 2,500 women, at the age of 50, performing a mammography scan; only one would be saved from death caused by the disease, while around 1000 women will be informed that they have suspicious lesions. Dr. Welch mentioned that 500 of these women would have to perform biopsies, and around 5 to 15 women are going to receive treatments for conditions that are never going to harm them.
Mammographay, with or against?
The findings of this study increases the international debate currently taking place which questions the effectiveness of mammography screening programs. The United States Preventive Services Task Force (USPSTF) released recommendations last November that mammography screening should be conducted every two years, instead of annually, for women at 50-74. Such recommendations were criticized by a lot of breast cancer professionals and organizations. Dr. Daniel Kopans, from Massachusetts General Hospital, commented on the results of the Norwegian study saying it “suggests that most of the decrease in breast cancer deaths is due to improvements in therapy with a lesser contribution from screening. There are large, published studies from Sweden and the Netherlands that show that most of the decrease in deaths is actually due to screening and not therapy.”