LOUISVILLE, Ky. – New guidelines recommended by a National Cancer Institute working group are a call for additional study and should not cause physicians to radically change how they diagnose, treat and communicate with patients, say two experienced cancer doctors at the James Graham Brown Cancer Center at the University of Louisville.
The working group’s report, “Overdiagnosis and Overtreatment: An Opportunity for Improvement,” was published Monday in The Journal of the American Medical Association.
Dr. Jason A. Chesney, deputy director of the cancer center and medical director of its clinical research trials office, and Dr. Anthony E. Dragun, associate professor and vice chair of radiation oncology, both say the NCI working group report requires additional study before being implemented because it does not take into account all factors leading to a definition and diagnosis of cancer.
The report recommends changing the definition of cancer and even removing the word from some common diagnoses because it creates fear in patients, causing them to seek what may be potentially harmful or unneeded treatments such as surgery.
For example, the premalignant condition known as ductal carcinoma in situ, or DCIS, should be renamed to eliminate the word “carcinoma,” say the report’s authors, who represent a cross-section of cancer physicians and researchers from across the United States. They also recommend that many lesions uncovered by breast, prostate, thyroid, lung and other cancer screenings should not be called cancer but are better defined as indolent lesions of epithelial origin, or IDLE conditions.
Chesney and Dragun, however, both cite the problem of identifying with certainty which lesions will not progress into potentially life-threatening cancers. Changing the terminology will not solve that problem.
“The problem with reclassifying pre-cancerous lesions as non-cancer is that we are confident that a certain percentage will, in fact, develop into full-blown cancer even with definitive therapy,” Chesney says. “For example, 19 percent of DCIS treated with surgery and radiation will nevertheless recur. We do not yet have the technology to determine which of these pre-cancerous lesions will develop into cancers and which will stay small and not cause health problems. ”
Both call for continued study before physicians radically alter their diagnoses and treatment practices. “Randomized clinical trials … should be pursued prior to the arbitrary issuing of new guidelines,” Dragun says. Chesney’s advice: “For now, I recommend that patients continue to receive screening as directed by their physicians, and let evidence guide future potential withdrawals in screening practices and the war on cancer.”
Chesney’s and Dragun’s complete commentaries on the JAMA report are shown below:
Dr. Jason A. Chesney:
“The problem with reclassifying pre-cancerous lesions as non-cancer is that we are confident that a certain percentage of these will develop into full blown cancer even with definitive therapy. For example, 19 percent of ductal carcinoma in situ’s of the breast treated with surgery and radiation will nevertheless recur (as reported in “Cancer,” Volume 103, Issue 6, pages 1137–1146, 15 March 2005).
“Importantly, we do not yet have the technology to determine which of these pre-cancerous lesions will develop into cancers and which will stay small and not cause health problems. Studies are now underway to develop better molecular and imaging signatures that determine which of these lesions does not need to be removed or even detected. However, the gold standard in medicine to develop evidence-based approaches, clinical trials, are difficult in this population, since the majority of women want the lesion removed and would not agree to be subjected to randomization or the risk associated with new treatment approaches.
“The authors also cite data indicating that for certain cancers such as thyroid and melanoma, screening has expanded and along with it, the detection of indolent pre-cancers that they predict won’t cause future health problems or even death. For example, while the incidence of melanoma has increased 199 percent in the 35 years from 1975-2010, the death rate has only increased by 32 percent.
“However, these data are only a correlation and no cause-and-effect relationship between these two percentages can be determined with the data they present. For example, the rise in melanoma diagnoses is no doubt due in part to improved awareness, screening and access to health care. However, the committee members do not consider that the rise in incidence also may be due to external factors unrelated to their hypothesis that aggressive screening does not necessarily lead to reductions in cancer-related deaths. One cause could be the use of tanning beds which became widespread during the study period, leading to increased ultraviolet exposure year-round and during the times when sun exposure is low, such as in the early mornings and late evenings. Recent studies have revealed that this tanning bed use increases the risk of melanoma.
“Accordingly, the rise in melanomas detected may be due to more melanomas developing as a result of increased ultraviolet exposure that occurred concurrently with better screening. The marked increase in melanoma diagnoses with only a small increase in deaths thus may be a huge success story for screening since increased doctor and patient awareness and skin biopsies may have prevented a massive increase in melanoma-related deaths over the last two-three decades.
“Ultimately, the only way to definitively address these questions is to randomize patients to receive screening versus no screening. This has obvious ethical implications that have thus far prevented such trials’ implementation. For now, I would recommend that patients continue to receive screening as directed by their physicians and let the evidence guide future potential withdrawals in screening practices and the war on cancer.”
Dr. Anthony E. Dragun:
“In terms of breast cancer – and DCIS in particular – we are at a point in history where these lesions are being detected earlier and earlier. Thus, we are entering an era where minimally invasive surgery should be the norm and non-surgical therapies should be investigated.
“Paradoxically, we are observing, at our institution and at many across the country, increasing mastectomy rates along with rising popularity of elective mastectomy, known as prophylactic amputation of the unaffected contralateral breast.
“This trend toward more radical surgery in breast cancer is likely multifactorial, but is clearly a movement backward and directly opposed to the four decades of accumulated evidence for breast conservation. Efforts to reclassify entities such as DCIS may have an impact in reversing these trends, but will likely have their own unintended consequences. Randomized clinical trials of non-surgical treatment for this condition should be pursued prior to the arbitrary issuing of new guidelines.”