Key Organizations Offer No Consensus on Mammography

SAN DIEGO--Women between the ages of 40 and 49 must still decide for themselves if undergoing a mammography is appropriate for them, according to a panel of experts at the American College of Physicians (ACP) Annual Session. The inability of key organizations to come to a decisive conclusion is the result of conflicting studies and the fact that "each organization espouses different rules of evidence," said Mary E. Costanza, MD, professor of medicine, University of Massachusetts Medical School.

With eight randomized trials involving half a million women, mammography is the most studied cancer-detecting tool in history, Dr. Costanza said. About 186,000 women were diagnosed with breast cancer in 1997, she pointed out, and of those, 61,000 will die. "This issue is becoming more significant as baby boomers age," she said.

The controversy does not apply to the benefits of mammography for women over 50 years of age, but for younger women, key groups can’t agree.

NIH. The National Institute of Health Development Conference’s official comment on the issue is as follows: "The data currently available do not warrant a universal recommendation for mammography for all women in their 40s. Each woman should decide for herself whether to undergo mammography." Dr. Costanza referred to the NIH’s stance as "unhelpful."

Unanswered Questions

NCI. The NCI’s recommendation that "women in their 40s should be screened every 1 to 2 years with mam-mography" also leaves many unanswered questions, she said. "They say yes, but they’re unclear about the interval. It’s kind of a leap of faith."

ACP. The American College of Physicians, she noted, recommends annual screening for women of any age who have a personal history of breast cancer or are otherwise at increased risk.

Task Force. The US Preventive Services Task Force says, "There is insufficient evidence to recommend for or against routine mammography or [CBE] clinical breast exam for women aged 40 to 49."

AAFP. The American Academy of Family Physicians, in what Dr. Costanza referred as a "pretty vague" decision, suggests that women in their 40s be counseled about the potential risks and benefits of screening mammography and clinical breast examination.

ACS. The American Cancer Society recommends annual mammography for women beginning at age 40, "and they are very clear about it," Dr. Costanza commented.

Other groups that make a clear recommendation for annual screening are the American College of Radiology and the American College of Obstetricians and Gynecologists.

Several factors create difficulties in assessing the viability of mammography screening for women 40 to 49, said Margaret T. Mandelson, PhD, assistant scientific investigator, Center for Health Studies, Group Health Cooperative of Puget Sound. For example, she said, the incidence of breast cancer is much lower in younger women; mammography is less sensitive in younger women, who tend to have denser breasts; and there may be a shorter preclinical phase of the disease in younger women.

Although a number of randomized mammography trials have taken place in the past, further randomized trials in the United States in this age group are unlikely, Dr. Mandelson said. Instead the NCI has established the National Breast Cancer Surveillance Consortium, "which will perform pooled analyses and provide a platform for future research focusing on mammography," she said.

Eight sites around the country are committed to collecting similar data, including risk factors, screening results, and outcomes. "We’ll be relying more and more on observational studies in the fugure," she noted.

What do physicians do in the meantime? Dr. Harold Sox, Joseph M. Huber Professor and Chair of the Department of Medicine at the Dartmouth-Hitchcock Medical Center, and new President of the ACP, suggests that primary physicians need to script themselves in advance, addressing the risks of screening, the effectiveness, the harms (such as the 50% chance of false-positives after 10 years of annual mammograms), and the patient’s potential anxiety after the mammogram.

"When speaking to women seeking advice, you should know the facts," Dr. Sox said. "If the patient is more concerned about having to possibly deal with a false-positive, she may not be a candidate for early mammography. If she’s more concerned about being diagnosed with breast cancer, then she may be a candidate for mammography."