The prostate-specific antigen (PSA) test is commonly used in men for prostate cancer screening. However, there have been concerns the test is not specific enough. Only one-third of men with elevated PSA are diagnosed with prostate cancer following a biopsy, indicating that a large proportion of patients undergo unnecessary prostate biopsy.
New research conducted at Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine suggests that free circulating DNA (fcDNA) blood levels could be a new biomarker, indicating the presence of prostate cancer and improving the specificity of the PSA test. That research will be presented by lead author Rakesh Singal, M.D., associate professor of medicine and co-leader of the Prostate, Bladder and Kidney Cancers Site Disease Group at Sylvester, at the 105th Annual Scientific Meeting of the American Urological Association (AUA).
Singal and his team examined the usefulness of fcDNA analysis in a typical prostate cancer screening setting. They examined the fcDNA blood levels of more than 250 men with PSA levels of >4 ng/mL and/or abnormal digital rectal exam and found that high fcDNA levels were significantly associated with prostate cancer risk. In fact, the combined use of fcDNA with PSA levels improved the specificity of prostate cancer detection by fivefold as compared to the use of PSA levels alone. Singal says their study indicates “fcDNA may be a reliable predictor of prostate cancer and may reduce the number of unnecessary biopsies.”
Alan Pollack, M.D., Ph.D., professor and chairman of radiation oncology at Sylvester, says Singal’s study “is exactly what is needed to reduce frequency of prostate biopsies. The technology may also be useful to the success of the treatment later.”
Singal’s team from Sylvester included Mark Soloway, M.D., professor and chairman of urology, Murugesan Manoharan, M.D., professor of urology and co-leader of the Prostate, Bladder and Kidney Cancers Site Disease Group at Sylvester, Isildinha Reis, Ph.D., research associate professor of epidemiology and public health, Edna Gordian, MA, senior research associate, and Kavitha Ramachandran, Ph.D., associate scientist.
“Free circulating DNA might aid in screening for prostate cancer,” says Anthony Y. Smith, M.D., an AUA spokesman. “We need to show that these numbers are reliable and that they truly increase the specificity of PSA so that when used in combination with PSA, they improve our ability to select patients for prostate biopsy.”