Radiology and breast-imaging doctors make a case for annual mammograms starting at age 40; other groups' advice varies

Centers for Disease Control and Prevention photo

Kentucky Health News

A recent study found that younger women of breast-screening age are more likely to develop aggressive breast cancers than older women, which reinforces the American College of Radiology and the Society of Breast Imaging's recommendation for annual mammograms starting at age 40.

“Aggressive cancers in women in their 40s must be identified early to be effectively treated. Letting these tumors grow even one extra year before screening greatly increases odds that the woman will die from breast cancer. Women 40 to 49 should be screened regularly,” Dr. Debra Monticciolo, chair of the American College of Radiology Breast Imaging Commission, said in a news release.

Other groups have somewhat different advice. The recommendations of the U.S. Preventive Services Task Force are that average-risk women who are 50 to 74 years old should have a screening mammogram every two years, and that average-risk women who are 40 to 49 should talk to their doctor about when to start and how often to get a screening mammogram.

The American Cancer Society recommends women with an average risk of breast cancer should begin having yearly mammograms at age 45, and can start having them every other year beginning at age 55. It adds that women should be able to start the screening as early as 40 if they want to.

The ACR, SBI, American Congress of Obstetricians and Gynecologists, National Comprehensive Cancer Network and others recommend that women start yearly mammograms at 40, says the radiology college's news release.

The college disputes the claim that mammogram results in overdiagnosis, citing a British Medical Journal study based on direct patient data that found overdiagnosis in about 2 percent of cases, which the college said fits with the American Cancer Society findings.

The college's news release says overdiagnosis is likely between 1 percent and 10 percent, largely due to condition called ductal carcinoma in situ, a noninvasive cancer that is often treated to avoid the potential development of an invasive cancer.

The college argues that concerns about "overdiagnosis, survival and screening versus treatment effectiveness" are "based on assumptions, many of which are unsupported, rather than direct patient data and should not affect breast cancer screening policy."

It also points to  two large studies that  found women who get regular mammograms cut their breast-cancer death risk in half, and that annual screenings have more live-saving benefit than biennial screenings for every age group.

Since the 1980s, when mammograms became widely done, the U.S. breast cancer death rate, which had been stable for decades, has dropped 38 percent as more cancers are found early, the release says.

The National Cancer Institute says about 12 percent of women in the United States today will develop breast cancer at some time in their lives, which means that if the current rate stays the same, a woman born today has about a one in eight chance of being diagnosed with breast cancer in their lifetime.

“Giving the second-leading cancer killer in women a head start through reduced or delayed screening can be lethal for these women. Starting screening at age 40 remains the best policy,” Dr. Wendy B. DeMartini,  president of the Society of Breast Imaging, said in the release.

The Lannin and Wang study was published in the June 8 New England Journal of Medicine.