Velocity of PSA Test Indicates Prognosis

Elevated levels of the prostate-specific antigen (PSA) blood test is indicative of prostate cancer, but can also be caused by prostate inflammation or enlargement or other conditions.

The PSA test is used to screen patients at risk for prostate cancer, but even after a negative biopsy, if the PSA levels increase with time, a manifestation of the disease is the mostly likely consequence.

Urologists at Northwestern Memorial Hospital, (Chicago, IL, USA), looked in their database at the history of 1,358 patients who underwent prostate biopsy after previous screening with three PSA tests between 2003 and 2010. There were 106 who had a PSA velocity score of 0.35 ng/mL/year and a negative biopsy. From these, of the 97 patients with a rising PSA trend or velocity, who had a subsequent negative biopsy, they found that 66% of patients were eventually diagnosed with prostate cancer, 20% had a benign prostate, 8% had prostatitis and 6% had premalignant lesions. False-negative tests can often be explained by low volume or high Gleason grade disease, prior resolved prostatitis, or possible PSA assay standardization bias.

William Catalona, MD, director of the clinical prostate cancer program at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University said, "Our findings show an elevated and rising PSA level or velocity should lead a clinician to follow a patient more closely, even if he has a negative biopsy. One negative biopsy isn't the end of the road." Professor Catalona known as the father of the PSA screening was the first to show in 1991 that a simple blood test measuring PSA levels could be used to detect prostate cancer.

The PSA test has come under fire as a screening test because it sometimes prompts biopsies that turn out to be normal. Gregory Auffenberg, MD, a resident in urology at the Feinberg School, commented, "This underscores the importance of using a patient's individual PSA trend when deciding whether to pursue a prostate biopsy. It is not enough to only look at an individual PSA value when historical data is also available." The results of the study were presented on May 18, 2011, at the American Urological Association Annual Meeting held in Atlanta (GA, USA).

Related Links:
Northwestern Memorial Hospital