The nation's largest medical specialty group is challenging the widely accepted recommendation that women routinely undergo mammograms in their 40s, saying the risks of the breast exams may outweigh the benefits for many women.
Reopening a long-running debate, the American College of Physicians, which represents 120,000 internists, issued new guidelines today that instead urge women in their 40s to consult with their doctors about whether to have the breast X-rays.
The group based its recommendations on a comprehensive review of mammography research that concluded that the benefit is less clear for women in their 40s than for those 50 and older, and that screening carries significant risks, including exposure to radiation and unnecessary biopsies, surgery and chemotherapy.
The guidelines conflict with long-standing recommendations from several other leading medical groups, including the American Cancer Society and the National Cancer Institute.
"We agree that mammography can save lives," said Douglas K. Owens of Stanford University, who chaired the committee that wrote the guidelines being published in the Annals of Internal Medicine. "But there are also potential harms. We don't think the evidence supports a blanket recommendation."
The new guidelines elicited mixed reactions from breast cancer doctors, researchers and patient advocates. Some condemned them, saying mammograms help catch tumors at their earliest, most treatable stage, reducing the death toll from the common malignancy. Breast cancer tends to be especially deadly when it strikes women in their 40s, they noted.
"The danger here is that some women will elect not to get screened," said Robert A. Smith, director of cancer screening at the American Cancer Society. "Mammography is the single most effective way of finding breast cancer early, and when we find breast cancer early, women have the greatest chance of successful treatment."
But others said the recommendations represent a more nuanced approach that better reflects what is known about the benefits and drawbacks of mammography.
"I think it's right on target," said Russell Harris of the U.S. Preventive Services Task Force, which issues the federal government's official recommendations on preventive medicine. "I would like to see more women stop and think about the decision."
Annual MRI exams
The new guidelines come less than a week after the American Cancer Society issued guidelines that, for the first time, recommend that women at greatest risk of breast cancer also undergo annual MRI exams. That triggered a similar debate over the risks and benefits of aggressive screening.
Owens acknowledged that the conflicting recommendations may confuse some women, but he said the panel concluded that it was important to present a realistic assessment.
"All we're saying is that women should be informed about the risks and benefits so they can make a decision based on all the facts," Owens said.
Breast cancer strikes more than 212,000 U.S. women each year and kills more than 40,000, making it the second most common cancer in women, after skin cancer, and the No. 2 cancer killer, after lung cancer.
Since the 1990s, the Cancer Society and other groups have been recommending that women begin having mammograms every year or two at age 40, and they credit the exams with helping reduce the death rate from the disease. But the recommendations have long been mired in controversy, with some researchers saying that the benefit in that age group is marginal and that the testing subjects thousands to overdiagnosis and overtreatment.
To reexamine the issue, the College of Physicians asked a six-member panel of experts to develop new guidelines based on a review of scientific literature between 1966 and 2005. Unlike previous reviews, the analysis of 117 studies included an evaluation of the negative consequences of mammograms, the group said.
The panel concluded that routine mammography screening might reduce the breast cancer death rate by about 15 percent for women in their 40s, but the data are so unclear that it "could be larger or nearly zero." In contrast, mammograms cut the death rate by a clear 22 percent for women age 50 and older, the group said.
That possible "modest" benefit for women in their 40s needs to be weighed against the risks, the panel concluded. As many as half of all women undergoing annual mammograms throughout their 40s may have a false alarm, which often leads to repeated exams and biopsies, causing anxiety, pain and possibly disfigurement.
Mammograms tend to detect a very early form of breast cancer known as ductal carcinoma in situ (DCIS), which may never become life-threatening, the panel noted. Nevertheless, a DCIS diagnosis leads to lumpectomies, mastectomies, radiation and chemotherapy. Mammograms can also miss some cancers, falsely reassuring women, the panel noted.
"The question is: Does the benefit outweigh the harms?'' Owens asked. "The evidence doesn't allow you to answer that question for every woman in her 40s."
Some patient advocates criticized the recommendations, saying current risk-assessment techniques cannot reliably differentiate which women are most likely to benefit from mammography.
But others endorsed the approach.
"We would all want this to be a simple issue, but it is not," said Carolina Hinestrosa of the National Breast Cancer Coalition, a Washington-based advocacy group. "Women need to know the truth and deserve it from their physicians."
Doctors and researchers were similarly divided. While some endorsed the guidelines, others said drawing a sharp distinction between the 40s and 50s is arbitrary.
"I think it's an outrage," said Daniel B. Kopans, a professor of radiology at Harvard Medical School. "This really is misleading women."