Scientists urge narrower definition of cancer
A group of experts advising the nation’s premier cancer research institution has recommended changing the definition of cancer and eliminating the word from some common diagnoses as part of sweeping changes in the nation’s approach to cancer detection and treatment.
The recommendations, from a working group of the National Cancer Institute, were published Monday in The Journal of the American Medical Association.
They say, for instance, that some premalignant conditions, like one that affects the breast called ductal carcinoma in situ, which many doctors agree is not cancer, should be renamed to exclude the word carcinoma, so that patients are less frightened and less likely to seek what may be unneeded and potentially harmful treatments that can include the surgical removal of the breast.
The group, which includes some of the top scientists in cancer research, also suggested that many lesions detected during breast, prostate, thyroid, lung and other cancer screenings should not be called cancer at all but should instead be reclassified as IDLE conditions, which stands for “indolent lesions of epithelial origin.”
While it is clear that some or all of the changes may not happen for years, if it all, and that some cancer experts will profoundly disagree with the group’s views, the report from such a prominent group of scientists who have the backing of the National Cancer Institute brings the discussion to a higher level and will most likely change the national conversation about cancer, its definition, its treatment and future research.
“We need a 21st-century definition of cancer instead of a 19th-century definition of cancer, which is what we’ve been using,” said Dr. Otis W. Brawley, the chief medical officer for the American Cancer Society, who was not directly involved in the report.
The impetus behind the call for change is a growing concern among doctors, scientists and patient advocates that hundreds of thousands of men and women are undergoing needless and sometimes disfiguring and harmful treatments for premalignant and cancerous lesions that are so slow growing they are unlikely to ever cause harm.
Cancer researchers warned about the risk of overdiagnosis and overtreatment as a result of new recommendations from a government panel that heavy smokers be given an annual CT scan. While the policy change, announced Monday but not yet made final, has the potential to save 20,000 lives a year, some doctors warned about the cumulative radiation risk of repeat scans as well as worries that broader use of the scans will lead to more risky and invasive medical procedures.
Officials at the National Cancer Institute say overdiagnosis is a major public health concern and a priority of the agency.
“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,” said Dr. Harold Varmus, the Nobel Prize-winning director of the National Cancer Institute. “Just as the general public is catching up to this idea, there are scientists who are catching up, too.”
One way to address the issue is to change the language used to describe lesions found through screening, said Dr. Laura J. Esserman, the lead author of the report in The Journal of the American Medical Association and the director of the Carol Franc Buck Breast Care Center at the University of California, San Francisco. In the report, Esserman and her colleagues said they would like to see a panel convened to address the issue, led by pathologists, with input from surgeons, oncologists and radiologists, among others.
“Ductal carcinoma in situ is not cancer, so why are we calling it cancer?” said Esserman, who is a professor of surgery and radiology at the University of California, San Francisco.
Such proposals will not be universally embraced. Dr. Larry Norton, the medical director of the Evelyn H. Lauder Breast Center at Memorial Sloan-Kettering Cancer Center, said the larger problem is that doctors cannot tell patients with certainty which cancers will not progress and which cancers will kill them, and changing terminology does not solve that problem.
“Which cases of DCIS will turn into an aggressive cancer and which ones won’t?” he said, referring to ductal carcinoma in situ. “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.”
Norton, who was not part of the report, agreed that doctors do need to focus on better communication with patients about precancerous and cancerous conditions. He said he often tells patients that even though ductal carcinoma in situ may look like cancer, it will not necessarily act like cancer — just as someone who is “dressed like a criminal” is not actually a criminal until that person breaks the law.
“The terminology is just a descriptive term, and there’s no question that has to be explained,” Norton said. “But you can’t go back and change hundreds of years of literature by suddenly changing terminology.”
But proponents of downgrading cancerous conditions with a name change say there is precedent.
The report’s authors note that in 1998, the World Health Organization changed the name of an early-stage urinary tract tumor, removing the word “carcinoma” and calling it “papillary urothelial neoplasia of low malignant potential.” When a common Pap smear finding called “cervical intraepithelial neoplasia” was reclassified as a low-grade lesion rather than a malignancy, women were more willing to submit to observation rather than demanding treatment, Esserman said.
“Changing the language we use to diagnose various lesions is essential to give patients confidence that they don’t have to aggressively treat every finding in a scan,” she said. “The problem for the public is you hear the word cancer, and you think you will die unless you get treated. We should reserve this term ‘cancer’ for those things that are highly likely to cause a problem.”