"Blood tests that indicate prostatespecific antigen PSA levels are rising rapidly over time are of little use in detecting aggressive prostate cancer and should not be done a new study indicates. PSA is a protein produced by cells of the prostate gland. High levels of PSA can be a marker for prostate cancer although its far from a perfect screening tool experts say. Men with both high and low levels of PSA can have cancer or not have cancer. The thought was that since high PSA levels are correlated with prostate cancer rapidly rising levels of PSA called PSA velocity from one year to another would also be an indicator of prostate cancer. However the new study found that PSA velocity doesnt add any useful information beyond what physicians can already tell from other methods of prostate cancer screening including the onetime PSA level test and digital rectal exams. Current screening guidelines that recommend biopsies for men who have high PSA velocity but no other signs of prostate cancer  such as a suspected abnormality during a digital rectal exam or high PSA level during a single test  are leading to many unnecessary biopsies the researchers said. We found there was no strong association between PSA velocity and prostate cancer and virtually none with aggressive prostate cancer said study author Andrew Vickers of Memorial SloanKettering Cancer Center in New York City. The velocity didnt add anything more to detecting aggressive prostate cancers. The study is published online Feb.  in the Journal of the National Cancer Institute. The whole issue of prostate cancer screening  including the PSA test the digital rectal exam and PSA velocity  has been controversial said Dr. Otis Brawley chief medical officer of the American Cancer Society ACS. Part of the difficulty is while current screening methods are good at detecting cancer they cant distinguish between aggressive lifethreatening prostate cancers and those that are slowgrowing and relatively benign. And many prostate cancers are just that  of little risk to men during their lifetimes Brawley said. Current ACS prostate screening cancer guidelines recommend that men make an informed decision with their doctor about whether to be tested for prostate cancer. Research has not yet proven that the potential benefits of testing outweigh the harms of testing and treatment according to the ACS. As for PSA velocity the ACS doesnt have a position on what PSA velocity warrants a biopsy. But the National Comprehensive Cancer Network and American Urological Association guidelines do recommend biopsies based on high PSA velocities even in the absence of an elevated PSA or a suspicious digital rectal exam according to background information in the study. And many internal medicine and primarycare doctors in part because of fears of litigation do order biopsies based on fastrising PSA levels Brawley said. Its something that has become almost a community standard. If a guy has a PSA of . last year and a year or so later youve repeated it and its . because it has increased by a factor of  he gets sent to biopsy Brawley said. In the study researchers used data on more than  men in their s and s who took part in a drug trial for a prostate cancer prevention drug. The men in the study were all from the placebo arm meaning they had not received the drug. As part of the trial all of the men agreed to have a biopsy at the end of the trial needed or not. Researchers did find a statistical association between PSA velocity and the chances of a biopsy coming back cancerous. But when they factored in other things that can influence risk including a family history of the disease being older being black PSA level and results of a digital rectal exam there was virtually no association between PSA velocity and biopsy outcome. PSA velocity measurement is not useful Brawley said. Grace LuYao a cancer epidemiologist at the Cancer Institute of New Jersey who wrote an accompanying editorial said she agreed with the authors conclusions that PSA velocity does not seem to be a good predictor of prostate cancer. In addition tracking PSA levels overtime can also cause anxiety to men who often worry if their PSA level has suddenly shot up. According to the data PSA velocity does not add any value but it may add more anxiety LuYao said. More information The National Cancer Institute http has more on the PSA test. SOURCES Andrew Vickers Ph.D. associate attending research methodologist department of epidemiology  biostatistics Memorial SloanKettering Cancer Center New York City Otis Brawley M.D. chief medical officer American Cancer Society Grace LuYao Ph.D. M.P.H. cancer epidemiologist The Cancer Institute of New Jersey Feb.   Journal of the National Cancer Institute online"