Biennially or Annually?
Early breast cancer screening utilizing mammography has been one of the major factors behind the significant decrease in breast cancer mortality since the 1990s. As breast cancer screening modalities continue to evolve, medical organizations subsequently revise their recommendations to provide more up-to-date guidelines to more effectively utilize mammography for breast cancer screening.
Studies have shown that regular annual mammography screening of women with no symptoms of breast cancer has lowered the number of women who die from breast cancer by about 30 percent (1). However, in 2009, the USPSTF (United States Preventive Services Task Force) restructured their mammogram recommendations to advise women, between the ages of 50 and 74, who are at average risk for developing breast cancer to be screened every two years (biennially) (2). Women in their forties were initially recommended not to be screened routinely, which was later revised in 2015, to have the option to be screened every two years, depending on their risk factors and personal preferences.
False-Positives & Invasive Testing
According to research studies presented in the USPSTF website, frequent mammograms commonly lead to false-positive results resulting to unnecessary and invasive confirmatory testing in average-risk women. Over-diagnosis of mammogram findings which may otherwise not become a threat to health may lead to anxiety and harm.
These guidelines were still scientifically rejected by almost every major medical organization with demonstrated expertise in breast cancer care. Medical organizations, such as the American College of Radiology (ACR) and the Society of Breast Imaging (SBI), still continue to recommend that women of average risk to start getting their annual mammograms at age 40 (3). High risk women, on the other hand, are recommended to begin screening by age 30, but not younger than age 25. Based on results from a meta-analysis of a randomized control trial involving nearly 500,000 women in Europe and North America, following this recommendation for annual screening resulted in a 26% mortality reduction (4).
Biennial Screenings Increase Mortality & Late-Stage Diagnosis
Guidelines of biennial screening would miss approximately a third of cancers and would result in 6500-10000 additional breast cancer deaths each year (5). And by not getting annual mammograms at age 40, one may increase the chances of dying from breast cancer and the likelihood that treatment for the disease will be more extensive for the cancer once it is detected. In particular, premenopausal women tend to be diagnosed with more aggressive forms of breast cancer, which supports the need for annual screening where an early diagnosis can result in easier treatments and lower mortality (6).
Women Over 75
USPSTF had also concluded that the evidence was insufficient to assess the balance of benefits and harms of screening mammography in women aged 75 years or older. Many doctors tell older women that they no longer need mammograms. As the average lifespan continues to lengthen, these recommendations may not make sense for everyone. If other medical conditions would shorten your life before breast cancer would or if you would choose not to act on the cancer diagnosis, then you and your doctor may decide to stop mammography screenings.
Meanwhile, the federal government has banned Medicare and private insurance companies from basing mammography coverage on the USPSTF recommendations.
Yes, life begins at 40, but it is also the age to schedule your annual mammogram. Remember the best way to find breast cancer in its earliest stages is to supplement this screening, with a clinical breast examination and monthly breast self-examination.
- “Frequently Asked Questions about Mammography and the USPSTF Recommendations: A Guide for Practitioners,” Society of Breast Imaging
- “Final Recommendation Statement: Breast Cancer: Screening,” U.S. Preventive Services Task Force, 2016
- “Breast Cancer Screening With Imaging: Recommendations From the Society of Breast Imaging and the ACR on the Use of Mammography, Breast MRI, Breast Ultrasound, and Other Technologies for the Detection of Clinically Occult Breast Cancer,” Journal of the American College of Radiology, 2010
- “Efficacy of Screening Mammography: A Meta-analysis,” The Journal of the American Medical Association, 1995
- “United States Preventive Services Task Force Screening Mammography Recommendations: Science Ignored,” American Journal of Roentgenology, 2011
- “Breast Tumor Prognostic Characteristics and Biennial vs Annual Mammography, Age, and Menopausal Status,” JAMA Oncology, 2015