New Guidelines on Breast Cancer Screening

Breast cancer screening guidelines updated by American Cancer Society

(RxWiki News) The American Cancer Society (ACS), an influential voice in cancer policy and clinical care in the US for more than 100 years, recently shifted its recommendations for breast cancer screening.

On Tuesday, the ACS — which had previously taken an aggressive approach to breast cancer screening — issued new guidelines for women at average risk for breast cancer. Women at average risk include those with no family history of breast cancer, those who do not carry a gene that could increase breast cancer risk and those who did not have chest radiation at a young age.

The ACS now strongly recommends that these women begin getting mammograms at age 45, continue once a year until age 54 and then continue every other year — as long as they are in good health and have a life expectancy of 10 more years or longer. The ACS also no longer recommends clinical breast exams, in which physicians feel for breast lumps, for women of any age with no symptoms of breast abnormality.

Previously, the ACS urged women to get yearly mammograms from age 40 onward. Clinical breast exams were also recommended periodically for women in their 20s and 30s and yearly for women age 40 or older.

According to the ACS, these changes reflect the increasing body of evidence that mammograms are imperfect, are less useful among younger women and may have serious drawbacks like false-positive results. False-positives can sometimes mean women undergo painful, time-consuming and expensive tests — only to find out they never had breast cancer in the first place.

In an editorial about these guidelines, Nancy L. Keating, MD, MPH, and Lydia E. Pace, MD, MPH, wrote, "Despite the substantial interest and investment in research on breast cancer screening, there is uncertainty about the magnitude of mammography’s benefits and harms and how to select patients and screening strategies to optimize the balance between benefits and harms. In the face of such uncertainty, thoughtful, evidence-based guidelines can play a powerful role in shaping policy and practice, supporting decision making by clinicians and patients, and identifying key research priorities."

The new guidelines seem unlikely to settle the issue of when and how often to screen for breast cancer, however.

Some other influential groups recommend earlier and more frequent screening, and some recommend less. For instance, three key groups — the American College of Obstetricians and Gynecologists, the ACS and the US Preventive Services Task Force (USPSTF) — now recommend different ages for starting regular mammograms: 40, 45 and 50, respectively.

In 2009, the USPSTF caused an uproar when it declared that women in their 40s didn't need to get routine mammograms.

Learning from that experience, the ACS has softened its message, emphasizing that younger women should still be able to get mammograms if they want them — as long as they understand the risks.

According to Drs. Keating and Pace, the future of breast cancer screening is likely to entail a more personalized understanding of breast cancer risk.

"In the meantime, it is important to remember and emphasize with average-risk women older than 40 years that there is no single right answer to the question 'Should I have a mammogram?'" Drs. Keating and Pace wrote. "Instead, women should be supported in estimating and understanding their risk of developing breast cancer and articulating their values and preferences so that clinicians can help them make informed decisions."

According to the ACS, breast cancer is the most common cancer among women worldwide. In the US alone, an estimated 231,840 women will be diagnosed with breast cancer in 2015.

Even though breast cancer death rates have declined steadily since 1990 — largely due to improvements in early detection and treatment — an estimated 40,290 women in the US will die of breast cancer in 2015.

The new guidelines and editorial were published Oct. 20 in the journal JAMA.

The ACS and the National Cancer Institute supported the guidelines. Several authors disclosed potential conflicts of interest.

Review Date: 
October 21, 2015