Are We Overdiagnosing, Overtreating Breast and Prostate Cancer?
Cancer experts from the University of California, San Francisco, and the University of Texas Health Science Center at San Antonio have opined in the latest issue of the Journal of the American Medical Association that it is time to reevaluate current screening efforts for breast and prostate cancer. Why? Because although breast and prostate screenings are beneficial, they come “at the cost of over-diagnosis and over-treatment” according to Laura Esserman, MD, MBA, one of the authors of the opinion piece and co-leader of the breast oncology program at the UCSF Helen Diller Family Comprehensive Cancer Center.
More than 200,000 women are diagnosed with breast cancer each year, making it the most common cancer among women, according to the American Cancer Society. More than 40,000 women lose their battle with the disease annually. Among men, prostate cancer is the second most common cause of cancer death following lung cancer. More than 192,000 men will be diagnosed with prostate cancer in 2009, and more than 27,000 men will die of the disease.
For two decades, healthcare professionals and organizations have been making a concerted effort to increase participation in breast and prostate cancer screenings, and the numbers have increased. About 50 percent of men at risk of prostate cancer have a routine prostate-specific antigen (PSA) test and about 70 percent of women older than 40 report that they have had a recent mammogram.
It was hoped that increased screening would result in a reduction in deaths from breast and prostate cancer, yet overall cancer rates are higher, more men and women are being treated for breast and prostate cancer, and the incidence of later-stage or aggressive disease has not declined significantly.
One possible reason for these unexpected results is that breast and prostate cancer screening may be overdiagnosing low-risk cancers, and thus leading to overtreatment, without significantly reducing the burden of aggressive or more serious cancers. “So the basic assumption of these screening programs that finding and treating early stage disease will prevent late stage or metastatic disease may not always be correct,” the authors state.
Dr. Esserman, who is also professor of surgery and radiology and director of the UCSF Carol Franc Buck Breast Cancer Center, and other authors of the commentary, believe breast and prostate cancer screening need an overhaul. “We need to focus on developing new tools to identify men and women at risk for the most aggressive cancers,” she said in a UCSF news release. “If we can identify groups of patients that don’t need much treatment, or don’t need to be screened, wouldn’t that be great?” She notes that screening is not foolproof, and that for both breast and prostate cancer, the healthcare community should “invest in changing our focus from the cancers that won’t kill people to the ones that do.”
The authors emphasize that they are not saying screening is ineffective, but that “if you want to stop suffering and death from these diseases, you can't rely on screening alone.” They list four recommendations in their commentary, including reducing treatment for patients who have low-risk breast or prostate cancer, as diagnosing cancers that do not kill patients “has led to treatment that may do more harm than good.” Another recommendation is to develop tests that can distinguish between lethal and low-risk cancers.
American Cancer Society
University of California, San Francisco news release