Experts Call for Redefinition of 'Cancer'
Many growths are slow to progress and nonlethal, only leading to unnecessary treatment, panel says
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According to the experts writing in JAMA, the best-case scenario for cancer screening is when the tumor is slow-growing but also typically progressive. Colon cancer often acts in this way, the team noted, and colonoscopy has become an "effective" screening program.
In the meantime, however, "overdiagnosis" occurs. The experts say a redefinition of cancer may be needed to quell patient fears over indolent lesions and curb overdiagnosis and overtreatment.
"Use of the term 'cancer' should be reserved for describing lesions with a reasonable likelihood of lethal progression if left untreated," they wrote. Other growths would be classified in a lesser category, "indolent lesions of epithelial origin" (IDLE).
A change in mindset may also be needed for patients and health care workers alike. "Physicians, patients and the general public must recognize that overdiagnosis is common and occurs more frequently with cancer screening," the team wrote.
The recommendations are sure to spur debate, but one outside expert said that debate may be what is needed on this issue.
"We're still having trouble convincing people that the things that get found as a consequence of mammography and PSA testing and other screening devices are not always malignancies in the classical sense that will kill you," Dr. Harold Varmus, director of the National Cancer Institute, told The New York Times. "Just as the general public is catching up to this idea, there are scientists who are catching up, too."
But not everyone agrees. Dr. Larry Norton is medical director of the Evelyn H. Lauder Breast Center at Memorial Sloan-Kettering Cancer Center in New York City. He said the problem is that even some relatively indolent breast growths, such as ductal carcinoma in situ (DCIS), can go on to become progressive, lethal cancers.
"Which cases of DCIS will turn into an aggressive cancer and which ones won't?" he told the Times. "I wish we knew that. We don't have very accurate ways of looking at tissue and looking at tumors under the microscope and knowing with great certainty that it is a slow-growing cancer."