November 21, 2011
Cancer Screening Reform Needed
Since the National Cancer Institute developed the first guidelines on mammography screening over thirty years ago, advocacy and professional groups have developed guidelines focused on who should be screened, instead of communicating clearly the risks and benefits of screening, according to a commentary by Michael Edward Stefanek, Ph.D., the associate vice president of collaborative research in the office of the vice president at Indiana University, published online Nov. 21 in the Journal of the National Cancer Institute. Stefanek writes that too much time has been spent debating guidelines, instead of ongoing debates about who should be screened. He advocates educating people about the potential harms and benefits of screening.
The U.S. Preventative Task Force (USPTS) recommendations against routine mammography for women aged 40-49 sparked controversy followed by more studies on screening, notably a Norwegian study comparing cancer-specific mortality in screened and unscreened women, which found a small and statistically insignificant breast cancer mortality reduction in the screened group. Stefanek writes that "similar ambiguity" exists for prostate cancer screening, noting that the two largest and high quality studies gave conflicting results, with the USPTS recently issuing recommendations against PSA testing in healthy men. The National Lung Cancer Screening Trial reported a 20% relative decrease in lung cancer deaths among subjects undergoing CT scans compared with those receiving chest x-rays, but with the majority of positive results being false positives. Overall this situation leads Stefanek to the conclusion that despite all the analyses to date, we are on unsteady ground when we attempt to dictate who should and shouldn't undergo screening.
Stefanek poses the question of what we have taught the public about cancer screening, since the public invariably seems to feel that screening is almost always a good idea and that finding cancer early is the key to saving lives. He cautions that the public may persist in holding a biased view of screening if we continue to engage in guideline debates. Furthermore, new technologies, despite the potential for combating cancer, will likely result in false positives, false negatives, overtreatment, and under treatment, and incur important patient harms.
Stefanek writes that we have failed to truly educate the public about cancer screening, and that our approach to screening needs to be reformed. He says engaging patients in shared decision making, tracking the number of patients provided with information related to the harms and benefits of screening instead of just those who are screened, and uniting scientific and advocacy organizations with primary care provider organizations in this effort to inform about costs and benefits is needed. "If we agree on the premise that individuals are supposed to be informed before making medical decisions, including decisions about cancer screening, then the time and talent of such groups could be much better spent educating the public on the harms and benefits of cancer screening," Stefanek writes. "Screening can be very beneficial (or not), and screening messages should reflect the complexity of this decision."
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