PSA Can Be Elevated in Prostate Cancer-Free Men
No clinical evidence of cancer in some patients with low percentage free/total PSA either
TUESDAY, July 17 (HealthDay News) -- About one in five men with no clinical evidence of prostate cancer have levels of prostate-specific antigen (PSA) above 2.5 ng/mL and half have a percentage free/total PSA that is less than 25 percent, according to the results of a study in the July issue of the British Journal of Urology.
Pierre I. Karakiewicz, M.D., from the University of Montreal Health Center in Quebec, Canada, and colleagues measured PSA and percentage free/total PSA in 2,323 men at least 40 years old who had no clinical evidence of prostate cancer.
The researchers found that the median PSA level was 1.0 ng/mL but increased with age and the median percentage free/total PSA was 25 percent but decreased with age. However, 18.9 percent of men had PSA levels greater than 2.5 ng/mL and 50.5 percent of men had a percentage free/total PSA of 25 percent or less. Using a PSA cutoff of more than 2.5 ng/mL and a percentage free/total PSA of 25 percent or less or 15 percent or less, 53.2 percent or 26.6 percent of men were considered abnormal, respectively.
"Half of men with no clinical evidence of prostate cancer should have PSA levels of less than 1.0 ng/mL and a percentage free/total PSA of more than 25 percent," the authors conclude. "A PSA level threshold of 2.5 ng/mL would require a biopsy in 20 percent of men and a percentage free/total PSA threshold of 25 percent [or less] in half of the men. Alternatively, a percentage free/total PSA threshold of 15 percent [or less] would decrease the probability to 15 percent."