Reduce cancer risks by supporting care based on science, not special interests

IN the politically charged debate over breast-cancer screening, many may have missed a fact that the U.S. Preventive Services Task Force (USPSTF) considered: Sometimes diagnostic procedures cause cancers they were meant to detect.

Now we hear more evidence that tests intended to find cancer may actually cause it. On Monday, the Archives of Internal Medicine published research showing that radiation doses from common CT scans are higher than generally believed, often increasing cancer risks. One study estimated that about 29,000 future cancers could be related to CT scans in the United States in 2007 alone.

While radiologic testing has increased dramatically in recent years, its safety worries are not new. Concerns about radiation-induced cancer from X-rays contributed to the establishment of the U.S. task force in 1984. Lawmakers appointed this independent group of experts to review evidence and recommend guidelines to protect Americans.

The task force has examined evidence on cancer screening for decades — reporting that mammography finds cancer early and can reduce the death rate for about 15 percent of women with breast cancer. But the group also kept an eye on potential harms. And last month they released findings that for women in their 40s, the net benefits of mammography for average-risk women are smaller than previously thought. And because there's a close call between risks and benefits, the group recommends that women in this age group discuss their individual risks and benefits of screening with their doctors and make their own informed decisions on screening.

Opponents of health reform — many with links to businesses that sell breast-imaging products and services — tried to use the task force's recommendations to their advantage, claiming they were part of a plot to ration health care. This is not true. Free from political or business-related influence, the task force did not consider cost or coverage in making its recommendations.

This week's studies on CT scans are further cause for caution. They add to the growing evidence that in our desire to use technology to detect and cure disease, we may be exposing some people to too much radiation.

How should we react to this news? First, individual studies must be weighed against larger bodies of evidence. That's why we need independent expert groups such as the U.S. task force to continue their work. In the meantime, patients should talk to their doctors about pros and cons of diagnostic procedures to make a decision that's right for them. We must keep in mind that routine mammography is still the best way to detect breast cancer in most average-risk women. CT scans are also important for those who need them.

But there is still much to learn about cancer risk and environmental exposures such as radiation. Scientists worldwide — many at Group Health Research Institute, the University of Washington, and Fred Hutchinson Cancer Research Center — are studying these problems. Much of the $15 million in federal stimulus funding awarded to these institutions for comparative effectiveness research will analyze cancer diagnostic tools, tests and treatments. Funding such research is also part of health reform now before Congress.

Our health-care system needs this science to ensure that resources support measures proved to advance health — rather than being wasted on harmful procedures and treatments.

We cannot afford to let self-interested political and business lobbies impact important decisions about public health. Let's rely on independent scientific bodies such as the U.S. task force that work for the American public. And let's support independent doctors and scientists who produce and evaluate research on clinical effectiveness. Ultimately, it's the best way to improve health and save lives.