Canadian Panel: Cut Breast Cancer Screening for Women in 40s

The battle over breast-cancer screening for women in their 40s shows no signs of abating.

The Canadian Task Force on Preventive Health has recommended that women start screening for breast-cancer at age 50 rather than 40. In 2009, the U.S. Preventative Services Task Force (USPSTF) said much the same thing. Organizations such as the American College of Obstetricians and Gynecologists came out against the 2009 guidelines; the American College of Radiology is among those vocally opposed to the Canadian follow-up.

New breast cancer screening guidelines by the Canadian Task Force on Preventive Health (CTFOPH) recommend against annual screening of women ages 40 to 49 and extending time between screens for older women. According to a Nov. 21 ACR statement, the Canadian panel’s conclusions “ignore results of landmark randomized control trials which show that regular screening significantly reduces breast cancer deaths in these women” and thereby could lead to “thousands of unnecessary cancer deaths.”

The panel said the decision to screen should be made individually between doctor and patient, but that “although screening mammography reduces mortality from breast cancer among women aged 40 to 74 years, the absolute benefit is small - especially for younger women - and is partially offset by harms caused by unnecessary intervention.” The task force added that “available evidence does not support the use of MRI scans, clinical breast examination or breast self-examination to screen for breast cancer among women at average risk.”

The ACR points to recent Swedish and British-led breast cancer screening trials showing regular mammograms reduced breast cancer deaths by approximately one-third, including in women ages 40 to 49. The ACR views these studies’ exclusion from the Canadian panel’s consideration as raising “serious concerns” about the group’s analysis.

The USPSTF approach would lead to missing 75 percent of cancers in women 40 to 49 and up to a third of cancers in women 50 to 74, the ACR said, pointing to a February 2011 analysis by R. Edward Hendrick, PhD, and Mark A. Helvie, MD, of the University of Michigan published in in the American Journal of Roentgenology. Hendrick and Helvie concluded that, if USPSTF recommendations were followed, 6,500 additional women would die annually from breast cancer in the United States. A similar proportion of Canadian women will likely die unnecessarily each year from breast cancer if the CTFOPH guidelines are followed, the ACR asserted.

“These recommendations are derived from flawed analyses and they defy common sense. Women and providers who are looking for guidance are getting bad advice from both Task Forces,” said Barbara Monsees, MD, chair of the American College of Radiology Breast Imaging Commission.

According to National Cancer Institute data, since mammography screening became widespread in the early 1990s, the U.S. breast cancer death rate, unchanged for the previous 50 years, has dropped well over 30 percent. The American Congress of Obstetricians and Gynecologists (ACOG), American Cancer Society, American College of Radiology, and Society of Breast Imaging continue to recommend that women begin receiving annual mammograms at age 40.