By Ann Miller Baker
Men dreading the digital rectal exam (DRE) for prostate cancer screening might take heart from a recently published Canadian study that casts doubt on its effectiveness in the primary care setting. But a Moffitt Cancer Center prostate expert says there is still value in primary care doctors and patients discussing the use of DRE along with prostate-specific antigen (PSA) blood tests.
A review in the Annals of Family Medicine looked at seven previously published studies among more than 9,000 men to determine the diagnostic accuracy of DRE when performed in the primary care setting in Canada, a nation with universal health care. While a majority of Canadian primary care physicians routinely utilize DRE, only 38 percent believed it provided a survival benefit. Pooled predictive value of DRE was less than 50 percent across all studies. When viewed in context with its invasiveness and potential to lead to unnecessary biopsy, overdiagnosis and overtreatment, the review’s authors recommended against DRE’s routine use in an already overburdened Canadian primary health care setting.
"This is an intriguing study that probably could only have been done within a universal health care system such as Canada’s, where you have reliable and significant numbers of patient data," said Julio Pow-Sang, MD, chair of Moffitt’s Department of Genitourinary Oncology and a member of the prostate cancer guidelines panel for the National Comprehensive Cancer Network. He reasoned that the review’s recommendations speak to Canadian primary care physicians’ need to reduce the use of tests without clearly demonstrated benefit to the patient.
Pow-Sang is concerned that men might misinterpret studies such as this one "and think that I don’t need to worry about getting screened."
"This is a very controversial and emotional issue," said Pow-Sang. Before the advent of PSA blood test use, Pow-Sang noted that the suspicious prostate nodes found by practitioners using DRE often led to diagnosis of advanced stage cancers. Today, most of the digital exams are negative. "That’s both good and bad,” said Pow-Sang, “because, through PSA tests, we are finding very early cancers that may not need to be immediately treated but rather watched, which adds anxiety."
Currently, U.S. guidelines do not require PSA nor DRE, but rather a discussion between the physician and the patient about risks and benefits of prostate cancer screening. "In clinical practice," Pow-Sang says, "it’s still a very good idea to do DRE."
Moffitt Cancer Center does offer both DRE and PSA tests to screen for prostate cancer, after discussion between physician and patient. At its March 17th Men’s Health Forum for uninsured/underinsured men, 81 vouchers for free prostate cancer screening were given to attendees after a discussion of the risks and benefits of prostate cancer screening.