Breast exam guidelines now call for less testing
Potential harm of frequent mammograms outweighs benefit, task force says
Tuesday, November 17, 2009
Women in their 40s should stop routinely having annual mammograms and older women should cut back to one scheduled exam every other year, an influential federal task force has concluded, challenging the use of one of the most common medical tests.
In its first reevaluation of breast cancer screening since 2002, the independent government-appointed panel recommended the changes, citing evidence that the potential harm to women having annual exams beginning at age 40 outweighs the benefit.
Coming amid a highly charged national debate over health-care reform and simmering suspicions about the possibility of rationing medical services, the recommendations immediately became enveloped in controversy.
"We're not saying women shouldn't get screened. Screening does saves lives," said Diana B. Petitti, vice chairman of the U.S. Preventive Services Task Force, which released the recommendations Monday in a paper being published in Tuesday's Annals of Internal Medicine. "But we are recommending against routine screening. There are important and serious negatives or harms that need to be considered carefully."
Several patient advocacy groups and many breast cancer experts welcomed the new guidelines, saying they represent a growing recognition that more testing, exams and treatment are not always beneficial and, in fact, can harm patients. Mammograms produce false-positive results in about 10 percent of cases, causing anxiety and often prompting women to undergo unnecessary follow-up tests, sometimes-disfiguring biopsies and unneeded treatment, including surgery, radiation and chemotherapy.
But the American Cancer Society, the American College of Radiology and other experts condemned the change, saying the benefits of routine mammography have been clearly demonstrated and play a key role in reducing the number of mastectomies and the death toll from one of the most common cancers.
"Tens of thousands of lives are being saved by mammography screening, and these idiots want to do away with it," said Daniel B. Kopans, a radiology professor at Harvard Medical School. "It's crazy -- unethical, really."
The new guidelines also recommend against teaching women to do regular self-exams and concluded that there is insufficient evidence to recommend that doctors do the exams or to continue routine mammograms beyond age 74.
Some questioned whether the new guidelines were designed more to control spending than to improve health. In addition to prompting fewer doctors to recommend mammograms to their patients, they worried that the move would prompt insurers to deny coverage for many mammograms.
The new recommendations took on added significance because under health-care reform legislation pending in Congress, the conclusions of the 16-member task force would set standards for what preventive services insurance plans would be required to cover at little or no cost.
About 39 million women undergo mammograms each year in the United States, costing the health-care system more than $5 billion.
Petitti said the panel was not influenced by the reform debate or cost issues.
A spectrum of women's health advocates, breast cancer experts and public health researchers praised the new guidelines.
"It's about time," said Fran Visco, president of the National Breast Cancer Coalition, a Washington-based patient advocacy group. "Women deserve the truth -- and the truth is the evidence says this is not always helpful and can be harmful."
While the American Cancer Society said it has no plans to change its guidelines, the National Cancer Institute said it will reevaluate its recommendations in light of the task force's conclusions.
The change is the latest development in a long controversy about mammography. The American Cancer Society and other groups have recommended that women regularly undergo the tests every one or two years beginning at age 40 to catch tumors early.
Many experts have begun to raise questions about routine screening methods, including the PSA blood test for prostate cancer and mammography, because they often trigger false alarms and catch precancerous growths and tiny tumors that would never become life-threatening but nonetheless prompt treatment.
The new guidelines were based on a comprehensive analysis of medical literature that included an update of a Swedish study involving about 70,000 women, new results from a British trial involving more than 160,000 women and data from the Breast Cancer Surveillance Consortium about more than 600,000 women.
In addition, the task force commissioned an unusual study funded by the National Cancer Institute that involved six independent teams of researchers conducting separate mathematical modeling studies of the risks and benefits of 20 screening strategies.
While annual mammography for all women beginning at age 40 reduced the death rate from breast cancer by at least 15 percent, the modeling studies indicated that the added benefit of starting before age 50 was modest, the researchers concluded.
For every 1,000 women screened beginning at age 40, the modeling suggested that just about 0.7 deaths from breast cancer would be prevented, while about 470 additional women would receive a false-positive result and about 33 more would undergo unnecessary biopsies.
"What isn't in the model but is an issue is how many extra imaging tests are done to follow up on things that turn out to be falsely positive and the harm of the anxiety that goes along with that," Petitti said. "Then there's the whole other line of problems that come into play, which is where there are some breast cancers detected that grow very slowly and would never have killed you."
For women age 50 and older, cutting back to screening every two years would maintain 81 percent of the benefits of testing annually while reducing by half the number of false-positives, the computer modeling study estimated.
Petitti stressed that the task force is not recommending against mammography, but that it hopes the new guidelines will lead more women to make their decisions based on their personal circumstances.
Those at high risk because of a family history of breast cancer, for example, or those who are simply more worried about the disease might still opt to have annual screenings, she said.
While the task force recommended against doctors teaching women how to perform regular breast self-exams and concluded that there was insufficient evidence to determine whether doctor exams were beneficial, several experts stressed that women should seek medical attention if they come across any unusual lumps.
Others worried that the conflicting advice would prompt women to delay or avoid the exams completely.
"People will end up not getting mammograms -- they'll just kiss them off," said Judith A. Luce, who treats breast cancer patients at San Francisco General Hospital.
"I'm concerned the sense of urgency about getting them done will fade."