by Mary Budinger —
The National Cancer Institute (NCI) is proposing to change some definitions of cancer because there is too much overdiagnosis and overtreatment of cancer. An NCI panel is recommending that definitions of some premalignant conditions no longer be called “cancer.”
The NCI has been evaluating the problem of overdiagnosis because it generally leads to overtreatment. “Use of the term ‘cancer’ should be reserved for describing lesions with a reasonable likelihood of lethal progression if left untreated,” the panel wrote.
The likelihood of a screening finding “incidentalomas” — the name given to incidental findings detected during medical scans that most likely would never cause a problem — has increased. When doctors and patients are aware a lesion exists, they typically feel compelled to biopsy, treat and remove it, often at great physical and psychological pain and risk to the patient. “There is now an increasing consensus that overdetection and overtreatment are becoming real problems,” said panelist Ian Thompson, M.D., from the University of Texas Health Science Center.
“We are 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 E. 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.”
The NCI panel says that a number of premalignant conditions, including ductal carcinoma in situ (DCIS) and high-grade prostatic intraepithelial neoplasia, should no longer be called “cancer.” Instead, the conditions should be labeled something more appropriate, such as indolent lesions of epithelial origin (IDLE), because millions of women who have received the diagnosis are not aware that it is usually a benign lesion, not a cancer, and thus have been mistreated.
Every year, approximately 60,000 women in the U.S. are diagnosed with DCIS.
In 1975, before mammography screening was prevalent, the incidence rate for breast cancer was 105 cases per 100,000 people. In 2010, the rate was 126 cases per 100,000 — an increase of 20 percent. Over that time period, the mortality rate decreased 30 percent — from 31 to 21 deaths per 100,000. However, “At least two-thirds of the mortality reduction is believed attributable to adjuvant therapy,” the panel noted. So we are finding more breast cancer because of screening, but fast-growing abnormalities are often driven into greater malignancy by the conventional chemotherapy, radiation and surgery-based standard of cancer care.
For instance, recent studies by researchers at the UCLA Jonnsson Comprehensive Cancer Center found that radiotherapy radiation wavelengths transformed breast cancer cells into highly malignant cancer stem-cell-like cells, with 30 times higher malignancy post-treatment.
Also, the fear brought on by diagnosis has been found to activate multidrug resistance proteins within cancer cells, explaining how our mental perception of cancer can influence its progression within our body.
“We need a 21st-century definition of cancer instead of a 19th-century definition of cancer, which is what we have been using,” said Dr. Otis W. Brawley, chief medical officer for the American Cancer Society, who was not directly involved in the report.
According to the panel, “optimal screening frequency depends on the cancer’s growth rate.” If a cancer is fast-growing, screening is “rarely” effective. However, if a cancer is slow-growing but progressive, with a long latency and a precancerous lesion such as colonic polyps or cervical intraepithelial neoplasia, “screening is ideal and less frequent screening (e.g., 10 years for colonoscopy) may be effective.” In the case of tumors that progress very slowly, detection is “potentially harmful because it can result in overtreatment.”
Some kinds of screenings work better than others. Screening for colon and cervical cancer, the panel noted, were found to have led to early detection and removal of precancerous lesions, which, in turn, have reduced incidence of late-stage disease. The incidence rate of colon cancer, for example, dropped 31 percent from 1975 to 2010 and the mortality rate dropped 45 percent.
“Changing the language we use to diagnose various lesions is essential to give patients confidence that they do not have to aggressively treat every finding in a scan,” said Dr. Esserman, professor of surgery and radiology at the University of California, San Francisco.
“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. Ductal carcinoma in situ is not cancer, so why are we calling it cancer?”
Source: Esserman, L. J., Thompson, I. M., Reid, B. Overdiagnosis and Overtreatment in Cancer: an Opportunity for Improvement. http://jama.jamanetwork.com/article.aspx? articleid=1722196.
Mary Budinger is an Emmy award-winning journalist who writes about integrative medicine. 602-799-6151.
Reprinted from AzNetNews, Volume 32, Number 5, October/November 2013.
December 3, 2013
Cancer, Health, Health Concerns, October/November 2013 Issue