A recent study published in the British Medical Journal (BMJ) regarding mammography screening has prompted renewed discussion about the value of mammograms in reducing deaths from breast cancer among women. Based on a number of concerns with the BMJ study, the American College of Obstetricians and Gynecologists maintains its recommendation that mammography screening be offered annually to women beginning at age 40.
The BMJ study is a re-review of data from a Canadian Trial that was conducted over three decades ago. Although this study found that mammography screening did not result in a reduction in deaths from breast cancer, there have been eight other randomized controlled trials that have shown mammograms do help prevent deaths for women in their 40s and 50s. In addition, data from numerous and much more recent observational trials have been published confirming a reduced mortality with modern mammography screening methods.
Two-thirds (66%) of the women in the BMJ study had tumors that were big enough to be felt on physical exam at the time of mammography screening, which means the cancer was more advanced. With modern mammography screening today, only 15% of breast cancer tumors can be felt; this means that more early-stage tumors that are missed by clinical breast exams are caught by mammograms when they are very small and more easily treated.
Individual experts and organizations may have different opinions regarding when to begin mammography screening and at what frequency. However, all of the leading health and medical organizations in the US-ACOG, the American Cancer Society (ACS), the National Comprehensive Cancer Network (NCCN), and the US Preventive Services Task Force- recommend regular screening mammography to reduce breast cancer mortality. In fact, the Canadian Trial data was part of the meta-analysis review that ACOG used in developing its 2011 mammography screening recommendations. ACOG, along with NCCN, and the ACS continue to recommend annual mammography starting at age 40 in women at average risk for breast cancer.