Prospective identification of National Institutes of Health category IV prostatitis in men with elevated prostate specific antigen.J Urol. 2000 Nov; 164(5):1550-3.JU
Although prostatitis may cause elevated prostate specific antigen (PSA), asymptomatic patients are not routinely screened for this diagnosis before transrectal biopsy is performed to rule out cancer. Many negative biopsies reveal evidence of prostatitis classified as National Institutes of Health (NIH) category IV prostatitis or asymptomatic inflammation. To our knowledge this report represents the initial study of the incidence of NIH category IV prostatitis in men before biopsy and its clinical significance.
MATERIALS AND METHODS
From 1996 to 1998 asymptomatic men with elevated PSA levels were evaluated for laboratory signs of prostatitis. Patients with expressed prostatic secretions or post-prostate massage urine (voiding bottle 3 [VB3]) positive for greater than 20 and greater than 10 white blood cells per high power field, respectively, received antibiotics for 4 weeks and were reevaluated after 6 to 8 weeks. Men without these clinical signs promptly underwent biopsy. Those with acute urinary tract infection and PSA greater than 30 ng./ml., without a rectum or who refused biopsy were excluded from study.
Of the 187 study patients 122 were evaluable with a mean PSA of 9.35 ng./ml., including 51 (42%) with laboratory signs of prostatitis. After treatment PSA was normal in 22 cases and remained elevated in 29, including 9 in which biopsy revealed cancer. The change or improvement in PSA was significantly greater in men with benign results than in those with prostate cancer (-21.32 versus -1.33%, p = 0.001). In the cohort with negative expressed prostatic secretion and VB3 results transrectal ultrasound guided biopsy was done promptly. Screening decreased the number of biopsies by 18% (22 of 122 cases). The positive predictive value of PSA for detecting biopsy proved cancer improved with screening for prostatitis (45 of 122 cases or 37% versus 36 of 71 or 51%). Long-term followup revealed continued normal or stable PSA in the prostatitis cohort.
Screening for NIH category IV prostatitis should be considered in men with elevated PSA. Although patients may be asymptomatic, anxiety caused by prostate cancer and diagnostic procedures contributes to the clinical significance of this disorder.