The American College of Obstetricians and Gynecologists (ACOG) has revised its recommendation for mammography screening, now suggesting that women undergo the test once a year beginning at age 40 years. The organization previously recommended screening mammography every 1 to 2 years beginning at age 40 years, and increasing to annually at 50 years.
In a statement issued by ACOG, guideline co-author Jennifer Griffin, MD, MPH, noted that the mammography screening recommendation was based on three factors: the incidence of breast cancer, the sojourn time for breast cancer growth (the time period between when a breast cancer may be detected by a mammogram while still very small and before it grows big enough to become symptomatic), and the potential to reduce the number of deaths from the disease.
Although women in their 40s have a lower overall incidence of breast cancer than do older women, women aged 40 to 49 years have the shortest average sojourn time (2 to 2.4 years), whereas women aged 70 to 74 years have the longest (4 to 4.1 years).
“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 2 years between mammograms,” explains Griffin.
The 5-year survival rate is 98% for women whose breast cancer tumors are discovered at their earliest stage—before the tumor is palpable, and when it is still small and confined to the breast.
In addition to encouraging breast self-awareness for women 20 years and older, ACOG continues to recommend clinical breast examinations once a year for women 40 years and older, and every 1 to 3 years for women 20 to 39 years. More frequent clinical breast examinations, annual magnetic resonance imaging (MRI), mammograms before age 40 years, or other breast screening may be recommended for women at high risk of developing breast cancer. However, the college does not recommend breast MRI for women at average risk.
ACOG’s revised breast cancer screening guideline appears in the August 2011 issue of Obstetrics & Gynecology as Practice Bulletin No. 122 (2011;118[2, Part 1]: 372-382), replacing Practice Bulletin No. 42, published in April 2003.