Effectiveness of Antibiotics Given to Asymptomatic Men for an Increased Prostate Specific Antigen

An elevated PSA between 4 and 10ng/ml can be due to prostate cancer (CaP), BPH or inflammation. Physicians often prescribe a course of antibiotics and then recheck the PSA to determine if inflammation may be the cause. In cases where the PSA decreases to less than 4ng/ml, the biopsy is often not performed.

A report from Dr. Sümer Baltaci and associates in the Journal of Urology suggests that this is not a good practice pattern, as the detection rate of CaP remains significant even when the PSA decreases to less than 4ng/ml following antibiotics.

Between 2006 and 2008, 100 consecutive men with a serum PSA 4-10ng/ml and no evidence of acute infection were given 400mg of ofloxacin orally for 20 days. A free and total PSA and urinalysis was then repeated 3 weeks after completion of antibiotics. All patients then underwent a 12-core prostate biopsy regardless of PSA response to antibiotics.

Mean patient age was 62.9 years, and mean total PSA was 6.05 and 5.55ng/ml before and after antibiotic treatment, respectively. A total of 23 men (23%) had CaP on prostate biopsy. The mean total PSA, free PSA and PSA density all decreased after antibiotics in both men with and without CaP, but was not statistically significant for total PSA and PSA density in men with CaP and free PSA in men without CaP. Furthermore, reductions within these parameters were not significantly different between men with and without CaP. In patients without CaP, the %-free PSA increased insignificantly after antibiotics, whereas mean %-free PSA decreased significantly after treatment in patients with CaP. Percent-free PSA change after treatment was significantly different between men with and without CaP.

In 17 of 100 men, the post-antibiotic treatment PSA decreased to <4ng/ml. Of these 17 cases, 5 (29.4%) had CaP, and free PSA, %-free PSA and PSA density did not discriminate this. Thus, the reduction in PSA was 7.15% in this study following antibiotic therapy, but a decrease in PSA to <4ng/ml did not decrease the risk of detection of CaP.

Baltaci S, Süer E, Haliloglu AH, Gokce MI, Elhan AH, Bedük Y

Written by Christopher P. Evans, MD, a Contributing Editor with UroToday

Source: UroToday