May 2, 2011 -- The recent guidelines issued by a government task force that do not recommend routine annual mammograms in women 40-49 may be having a negative impact, according to new research.
If screening mammograms are not done routinely in women in this age group, says researcher Lara Hardesty, MD, chief of breast imaging at the University of Colorado Hospital, Denver, "I am concerned the only way the breast cancer in these women will be detected will be when they are large enough to be felt by either the women or their health care provider."
Hardesty presented her research at the American Roentgen Ray Society annual meeting in Chicago.
She found a drop in the number of women ages 40 to 49 getting mammograms routinely at her hospital after the November 2009 guideline on mammography was issued by the U.S. Preventive Services Task Force (USPSTF). The mammography guidelines suggest women 40-49 discuss the risks and benefits of having a mammogram with their doctor and decide what to do on an individual basis.
The American Cancer Society and the American College of Radiology advise women to begin routine screening annually at age 40.
In another study presented at the same meeting, Donna Plecha, MD, director of breast imaging at University Hospitals at Case Medical Center in Cleveland, reported that cancers found in women 40 to 49 who had screening mammograms were smaller and found earlier than those found in women who did not have the test.
However, the current chair of the task force says the data from the study doesn't change what is known about the value of the test in women 40 to 49. "The recommendation of the task force is that the decision to screen should be individualized for women in this age group, taking into account each woman's values and her specific situation," says Virginia Moyer, MD, who is also professor of pediatrics at Baylor college of Medicine and Texas Children's Hospital in Houston. She reviewed the studies for WebMD.
Survey of Health Care Providers
Before the USPSTF guidelines took effect:
- 56% recommended annual screening for women 40 to 49.
- 33% recommended screening every two years.
- 11% recommended no screening.
After the USPSTF guidelines were issued:
- 20% recommended annual screening for women 40 to 49.
- 18% recommended screening every other year.
- 8% recommended not screening.
- 54% discussed the risk and benefits on a one-to-one basis, which is recommended by the USPSTF guidelines.
Hardesty also compared the number of screening mammograms done at her hospital in women 40 to 49 and in those age 50 and above in two time periods. The first was nine months before the USPSTF guidelines and the second was nine months after.
She found that before the USPSTF guidelines:
- 1327 patients 40 to 49 were screened.
- 4479 patients 50 and older were screened.
After the USPSTF guidelines:
- 1122 patients 40 to 49 were screened.
- 4498 patents 50 and above were screened.
"Of those 108,” she tells WebMD, “71 of those were in those women who were undergoing mammography and 37 were in those who were not having mammography screening.” Those detected by mammography were more likely to be found earlier. The tumors were also more likely to be smaller.
"I would agree with the American Cancer Society and the American College of Radiology to keep the guidelines for annual screening [beginning] at age 40," Plecha says. She reports serving as a consultant last year for Hologic, a medical imaging manufacturer.
Screening Benefits and Risks
An expert not involved in the new research cautions that the studies are small. They also involve only local populations. "Thus, they do not provide evidence that is generalizable to the U.S. population," says Robert A. Smith, PhD, director of cancer screening for the American Cancer Society.
However, he says, it is reasonable to expect a change in referral patterns for screening mammography based on the task force recommendation.
He is not aware of any national surveys of mammography use since the task force guidelines were issued. So it is not yet possible to measure the nationwide effect.
Moyer warns that the public frequently misunderstands the task force guidelines and thinks no women 40 to 49 should get a mammogram. Actually, she says, the guidelines recommend a woman discuss it with her doctor and decide.
"'We do know that on average, screening results in some degree of benefit for women from 40 to 74 years of age," she says. "For women in the 40- to 49-year-old age group, this benefit appears to be quite small, and has to be balanced against the known risks, which are greater in younger than in older women."
Among the risks are false-positive results and anxiety.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the peer review process, in which outside experts scrutinize the data prior to publication in a medical journal.