To address the growing problem of people being overdiagnosed and overtreated for cancer, a group of scientists convened by the National Cancer Institute has proposed a major update of the way the nation approaches diseases now classified as cancer.
When cancer-screening programs were widely initiated three decades ago, medical knowledge of the disease was more simplistic. The intent was to detect cancer at its earliest stages to reduce illness and mortality, but in fact early diagnosis has not led to a proportional decline in serious disease and death, the panel wrote.
Instead, screening programs are identifying not only malignant cancers, but also slow-growing, low-risk lesions, and sweeping them into the same treatment process. As a result, patients are being diagnosed and treated for forms of cancer that might never actually harm them – a phenomenon that’s been termed overdiagnosis, meaning “too much medicine.”
Now, with the advancement of scientific understanding of the biology of cancer, the authors say it is time for significant changes in practice and policy. The commentary was published in JAMA (2013; doi:10.1001/jama.2013.108415).
“By recognizing that cancer is not one disease, but a number of different diseases, we can individualize our treatment based on biology and avoid overtreatment,” said panel chair and breast cancer expert Laura J. Esserman, MD, MBA, of the University of California San Francisco. “The goal going forward is to personalize screening strategies, and focus screening policies on the conditions that are most likely to result in aggressive illness and death.”
Overdiagnosis is occurring across many medical conditions, but is particularly common in breast cancer, lung cancer, prostate cancer, thyroid cancer, and melanoma, said the authors. They cited DCIS, or ductal carcinoma of the breast, and Barrett’s esophagus as illustrations of how the detection and surgical removal of what have been called precancerous lesions have failed to deliver lower rates of invasive cancer.
By contrast, the authors said, colon and cervical cancer serve as examples of “effective screening programs in which early detection and removal of precancerous lesions have reduced incidence as well as late-stage disease.”