The American College of Obstetricians and Gynecologists (ACOG) has shifted course and issued new breast cancer screening guidelines that recommend mammography screening be offered annually to women beginning at age 40, citing the high incidence of breast cancer in the U.S. and the potential to reduce deaths from it when caught early.
Previous ACOG guidelines recommended mammograms every one to two years starting at age 40 and annually beginning at age 50. The American College of Radiology (ACR) and Society of Breast Imaging (SBI) have applauded the updated recommendations. Published in the August issue of Obstetrics & Gynecology , the recommendations now correspond with those of the American Cancer Society, ACR, SBI, American Society of Breast Disease (ASBD) and many other major medical associations.
The updated ACOG recommendations, now in-step with those of breast cancer experts, differ from the guidelines of the U.S. Preventive Services Task Force (USPSTF).
ACOG, like ACR, SBI and others, placed greater importance on saving lives while the USPSTF was primarily concerned with reducing false positive studies, most of which are resolved by a few additional mammographic views or ultrasound, according to ACR.
The USPSTF relied largely on computer modeling to argue that, in women age 40-49, only those with a family history of breast cancer or other high-risk factors should be screened and that women age 50-74 be screened biennially. However, there are no scientific data to support the age of 50 as a biological threshold for screening, ACR stated. It has been artificially marked by inappropriate grouping of data, the organization continued.
According to Jennifer L. Griffin, MD, MPH, of the University of Nebraska Medical Center in Omaha, who co-authored the guidelines, the change in mammography screening recommendations for women beginning at age 40 is based on three factors: the incidence of breast cancer, the sojourn time for breast cancer growth and the potential to reduce the number of deaths from it.
Although the sojourn time of individual cancers can vary, the greatest predictor is age. Women age 40-49 have the shortest average sojourn time (2 to 2.4 years), while women age 70-74 have the longest average sojourn time (4 to 4.1 years).
"Although women in their 40s have a lower overall incidence of breast cancer compared with older women, the window to detect tumors before they become symptomatic is shorter, on average," said Griffin. The five-year survival rate is 98 percent for women whose breast cancer tumors are discovered at their earliest stage, before they are palpable and when they are small and confined to the breast, ACOG noted. "If women in their 40s have annual mammograms, there is a better chance of detecting and treating the cancer before it has time to spread than if they wait two years between mammograms."
The college's breast cancer screening guidelines also address clinical breast exams (CBE) and breast self-awareness. It recommends an annual CBE performed by a physician for women age 40 and older. The college endorses educating women age 20 and older regarding breast self-awareness, an understanding of the normal appearance and feel of their breasts, but without a specific interval or systematic examination technique. Finally, ACOG advised that enhanced breast cancer screening, such as more frequent CBEs, annual MRI or mammograms before age 40, may be recommended for women at high risk of breast cancer.
According to ACOG, there is no consensus on the upper age limit for mammograms, although the benefits of screening decline with increasing age compared with the harms of overtreatment. Women age 75 and older should discuss with their doctor whether to continue getting mammograms, said Griffin.