"While it is not completely clear whether the tests are more often initiated by patient or provider, data suggest that men are often not informed about the limitations of the test and about the need to interpret the results of a positive or negative test result with those limitations in mind," she said.
Dr. Dragan Ilic, a senior lecturer at Monash Institute of Health Services Research at Monash University in Australia, and author of an accompanying journal editorial, said the data about the value of PSA tests remains confusing.
"Evidence from two recently published randomized, controlled trials provide conflicting recommendations on the merits of using the PSA test in screening men for prostate cancer," he added.
Doctors and patients are faced with conflicting evidence about the merits of screening and how to use the PSA test as a screening tool, Ilic said.
"In the absence of conclusive evidence to inform PSA testing, clinicians should initiate an informed discussion with patients, with the aid of appropriate patient education materials, to ensure that patients understand the uncertainty surrounding screening for prostate cancer and so can make an informed, shared decision," he said.
PSA is a protein made by the prostate gland. It is found in small amounts in the blood of healthy men, and is often elevated in men with prostate cancer, but also in men with benign prostate enlargement.
For more information on prostate cancer, visit the American Cancer Society.
SOURCES: Benny Holmstrom, urologist, department of surgery, Gavle Hospital, Gavle, Sweden; Mattias Johansson, Ph.D., postdoctoral fellow, Umea University, Umea, Sweden; Jennifer Stark, Ph.D., research fellow, Harvard School of Public Health, Boston; Dragan Ilic, M.D., Ph.D., senior lecturer, Monash Institute of Health Services Research, Monash University, Victoria, Australia; Sept. 25, 2009, BMJ, online