Among the changes in the American Cancer Society’s updated breast cancer screening guideline is that women with an average risk of breast cancer should undergo regular, annual screening mammography beginning at age 45 years, with women having an opportunity to choose to begin annual screening as early as age 40; women 55 years and older should transition to screening every other year (vs annual), but still have the opportunity to continue with annual screening; and routine screening clinical breast examination is no longer recommended, according to an article in the October 20 issue of JAMA.
Breast cancer is the most common cancer in women worldwide. In the United States, it is estimated that approximately 230,000 women will be diagnosed with breast cancer in 2015. Breast cancer continues to rank second, after lung cancer, as a cause of cancer death in women in the U.S., and is a leading cause of premature mortality for women. Even though death from breast cancer has declined steadily since 1990, largely due to improvements in early detection and treatment, an estimated 40,300 women in the U.S. will die of breast cancer in 2015. Early detection is associated with reduced breast cancer illness and death, according to background information in the article.
Since the last American Cancer Society (ACS) breast cancer screening update for average-risk women was published in 2003, new evidence has accumulated from long-term follow-up of randomized controlled trials and observational studies of organized, population-based screening programs. Evan R. Myers, M.D., M.P.H., of the Duke Evidence Synthesis Group, Duke Clinical Research Institute, Durham, N.C., and colleagues conducted a systematic review of the breast cancer screening literature to update the American Cancer Society 2003 breast cancer screening guideline for women at average risk for breast cancer (this study appears in JAMA); Diana L. Miglioretti, Ph.D., of the University of California Davis School of Medicine, and colleagues performed an analysis of Breast Cancer Surveillance Consortium mammography registry data to address questions related to screening intervals (this study appears in JAMA Oncology). Formulation of recommendations was based on the quality of the evidence and judgment (incorporating values and preferences) about the balance of benefits and harms.
The 2015 recommendations for breast cancer screening for women at average risk:
Women should undergo regular screening mammography starting at age 45.
Women 45 to 54 years of age should be screened annually.
Women 55 years and older should transition to biennial screening or have the opportunity to continue screening annually.
Women should have the opportunity to begin annual screening between the ages of 40 and 44 years.
Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer.
Clinical breast examination is not recommended for breast cancer screening among average-risk women at any age.
“The ACS endorses beginning annual screening mammography at age 45 years and transitioning to biennial screening at age 55 years, while retaining the option to continue annual screening, which some women may elect based on personal preference, clinical guidance, or both,” the authors write. “After careful examination of the burden of disease among women aged 40 to 54 years, the guideline development group (GDG) concluded that the lesser, but not insignificant, burden of disease for women aged 40 to 44 years and the higher cumulative risk of adverse outcomes no longer warranted a direct recommendation to begin screening at age 40 years.”
Regarding no longer recommending periodic clinical breast examination (CBE), the researchers write that “the absence of clear evidence that CBE contributed significantly to breast cancer detection prior to or after age 40 years led the GDG to conclude that it could no longer be recommended for average-risk women at any age.”
“This guideline is intended to provide guidance to the public and clinicians, and it is especially designed for use in the context of a clinical encounter. Women should be encouraged to be aware of and to discuss their family history and medical history with a clinician, who should periodically ascertain whether a woman’s risk factor profile has changed. If the woman has an average risk of developing breast cancer, the ACS encourages a discussion of screening around the age of 40 years. The ACS also recommends that women be provided with information about risk factors, risk reduction, and the benefits, limitations, and harms associated with mammography screening.”
“In conclusion, the ACS recommendations are made in the context of maximizing reductions in breast cancer mortality and reducing years of life lost while minimizing the associated harms among the population of women in the United States. The ACS recognizes that the balance of benefits and harms will be close in some instances and that the spectrum of women’s values and preferences will lead to varying decisions. The intention of this new guideline is to provide both guidance and flexibility for women about when to start and stop screening mammography and how frequently to be screened for breast cancer.”
Editorial: New Guidelines for Breast Cancer Screening in U.S. Women
“Will the new ACS guideline make it easier for clinicians and women to make decisions about screening mammography? In some ways, the messages from ACS and the U.S. Preventive Services Task Force (USPSTF), 2 major guidelines, are now more consistent. Both guidelines agree that for average-risk women younger than 45 years, the harms of mammography screening likely outweigh the benefits,” write Nancy L. Keating, M.D., M.P.H., of Harvard Medical School, Boston, and Lydia E. Pace, M.D., M.P.H., of Brigham and Women’s Hospital, Boston, in an accompanying editorial.
“For women older than 55 years, biennial mammography is likely to provide the best balance of benefits to harms. The new ACS recommendation to stop screening older women with life expectancies of less than 10 years is practical and consistent with the increasing emphasis on functional vs chronologic age. The more challenging decisions are for women aged 45 to 54 years, for whom ACS recommends annual screening, but for whom the USPSTF recommends no routine screening (age 45-49 years) or biennial screening (age 50-54 years). In communicating with patients, clinicians will have to balance the ACS’ recommendation for more frequent screening against the fact that younger women experience a lower absolute benefit from screening mammography.”