Changing the definition of cancer may reduce overtreatment
By Deborah Bach
When Dr. Brian Reid attended medical school in the 1970s, cancer was defined as a disease whose natural course is always fatal.
That has led to decades of doctors overtreating the disease, he said, and patients who automatically perceive a diagnosis as a death sentence.
“Generations of doctors have trained with that definition, so when they see the word cancer, they react with treatment,” said Reid, a researcher in the Human Biology Division at Fred Hutchinson Cancer Research Center.
“It’s just built into the system.”
But Reid and other members of a volunteer think tank convened at a meeting hosted by the National Cancer Institute hope to change that. In a paper that has generated media attention nationwide, the group has recommended adjusting how cancer is defined and avoiding the term altogether in some diagnoses.
The group, whose findings were published online Monday in The Journal of the American Medical Association, recommends that the term “cancer” be reserved only for lesions that are likely to become fatal if left untreated. Premalignant conditions – for example, ductal carcinoma in situ, a type of non-invasive breast cancer – should not be labeled as cancer, they suggest.
The group also recommends that low-risk lesions be reclassified as IDLE, or “indolent lesions of epithelial origin” conditions, rather than using the terms “cancer” or “carcinoma” to describe them.
The group found that while better screening and patient awareness have resulted in identifying a broader range of cancers and catching cancer earlier, they have not achieved a proportional reduction of the deadliest forms of the disease.
But doctors have continued to rely on an outdated definition of cancer and a resulting tendency to default to unnecessary treatment, Reid said.
“Overdiagnosis leads to overtreatment,” he said. “That’s the problem. If you overtreat, you’re not doing any good for the patient and you risk harm from the treatment.”
The think tank, which included close to 40 researchers, was formed last year to address the realization that thousands of patients nationwide are opting for unnecessary treatment for lesions that are unlikely to ever become a serious concern.
Reid co-authored the JAMA report with Dr. Laura Esserman, director of the Carol Franc Buck Breast Care Center at the University of California, San Francisco; and Dr. Ian Thompson, director of the Cancer Therapy & Research Center at The University of Texas Health Science Center.
Dr. Ruth Etzioni, a biostatistician in the Public Health Sciences Division at Fred Hutch, said overdiagnosis of cancer has been an issue for decades. In 2010, for example, researchers estimate that about 36,000 men nationwide were overtreated for prostate cancer at a cost of about half a billion dollars – and an immeasurable physical and emotional toll.
“The harm is in getting a treatment that you never would have been a candidate for, and all the anxiety that involves,” Etzioni said.
Reid and other members of the task force are also recommending that registries be created to monitor benign lesions so physicians and patients can make more informed decisions, an approach Etzioni agrees with. But she said care must also be taken to ensure that redefining cancer does not lead to inaccurate classification of potentially serious lesions.
“It’s very different, knowing that a good fraction of cancers are overdiagnosed in the aggregate, in the population, versus looking at cancer on a case-by-case basis and really distinguishing those that we do not want to treat,” she said.
View Reid and Etzioni’s interviews with local media:
Changing the definition of cancer
KCPQ-TV, July 30, 2013
In-studio interview with Dr. Ruth Etzioni of the Public Health Sciences Division
National Cancer Institute panel recommends redefining ‘cancer’
KING-TV, July 30, 2013
Interview with Dr. Brian Reid of the Human Biology Division