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Monday, November 30, 2009

The Mammogram Melee: How Much Screening Is Best?

By Alice Park and Kate Pickert

Women's breasts are not the usual topic of public discourse in Washington, at least not outside the context of a scandal. But for the past few weeks, the question of when women should be screened for breast cancer has become the subject of intense medical debate, partisan congressional bickering and a whole lot of confusion among mothers, daughters, sisters and friends, not only inside the Beltway but throughout the rest of the country.

Women's breasts are not the usual topic of public discourse in Washington, at least not outside the context of a scandal. But for the past few weeks, the question of when women should be screened for breast cancer has become the subject of intense medical debate, partisan congressional bickering and a whole lot of confusion among mothers, daughters, sisters and friends, not only inside the Beltway but throughout the rest of the country.

On Nov. 16, the 16 members of the independent U.S. Preventive Services Task Force recommended that most women delay routine mammograms until age 50 (instead of 40, as the panel advised in 2002). The task force cited enhanced analysis of the risks and benefits of screening as the reason for the new guidelines. But the recommendations went straight to the heart of the emotionally charged debate over the Democratic-sponsored health care reform legislation that is working its way through Congress. Republicans like Representative Marsha Blackburn charged that "this is how rationing begins. This is the little toe in the edge of the water." No one was more surprised, or less prepared, for the uproar over the new guidelines than the advisory panel itself. As a result, the merits of what the group is now recommending have been obscured by all the political smoke. Dr. Diana Petitti, a professor at Arizona State University and vice chair of the task force, says, "Our attempt to communicate [the risks and benefits of] routine screening was definitely lost."

The rumblings over the mammography message provide a useful window into why U.S. health policy does not always dovetail with the best available medical evidence, and certainly not with the best available data on costs. By and large, American patients (not to mention politicians and cancer advocacy groups) still subscribe to the view that every life is worth saving, no matter the cost, and that when it comes to prevention, screening is always good and more is always better. For decades, patients have been steeped in the notion that frequent screening is not just beneficial but also essential to the early detection of cancer. But such personal calculations do not apply in the same way to an entire population, where the benefit to some must be weighed against the harm to others.

Judging from the reaction to the new breast-cancer recommendations, that is proving to be a difficult reality for Americans to accept. But the task force's mammography advice probably marks the leading edge of similar recommendations to come. Already, new guidelines on Pap smear screening for cervical cancer have delayed the age at which young women should begin regular testing and reduced the frequency of testing in older women. Doctors are also questioning the usefulness of prostate-cancer screening among otherwise healthy middle-aged men, as studies begin to show that the test, which has many risks, may not necessarily lead to fewer deaths from the usually slow-growing cancer. The Senate health reform bill currently being debated would also rely on the task-force guidelines to determine what preventive medical services private insurers would be required to cover at no cost to patients. In a sign of how contentious evidence-based approaches may become, Secretary of Health and Human Services (HHS) Kathleen Sebelius quickly distanced the Obama Administration from the new mammography advice. She said in a statement, "Our policies remain unchanged," and cast doubt on whether private insurance--required by most states to cover routine mammograms beginning at 40--would be affected. "Keep doing what you're doing," Sebelius advised women.

Gail Wilensky, a former high-level HHS official under George W. Bush, called the Obama Administration's response "appalling and outrageous and a very good reminder of how hard it is going to be to move to evidence-based medicine whenever it goes against a sacred cow."

The Limits of Screening

A decade ago, doctors saw breast cancer as a monolithic disease that always progressed the same way, beginning with a single mutant cell that continued to divide and spread to the rest of the body. At the time, screening all women made sense, especially since annual mammograms had reduced deaths from breast cancer 3% each year since 1990. But as Dr. Russell Harris, a professor of medicine at the University of North Carolina at Chapel Hill and a member of the task force, points out, breast cancer occurs less frequently in younger women, and not every cancer is the same. Some tumors are indolent and slow-growing; others are aggressively malignant and blanket a body within months. Mammography is best at spotting the slowest-growing tumors, which are most common and generally do not spread beyond the breast or require treatment. Although these tumors are malignant, they rarely go on to cause clinical symptoms. But when detected, they are still treated as if they were potentially faster-growing--with a combination of chemotherapy, radiation, surgery and hormone therapy. "We can't figure out which is which," says Harris. "So we end up having to treat them all." (Read more..)


source: Time.com