Objectives: To assess possible predictors in determining criteria for repeat biopsy in a prostate cancer screening population.
Methods: A total of 50 207 men over 55 years-of-age have participated in a prostate cancer screening program in Otokuni, Kyoto, Japan for 12 years. Transperineal systematic biopsy was carried out in case of positive digital rectal examination (DRE) or positive transrectal ultrasonography (TRUS) or a prostate-specific antigen (PSA) value greater than 10.0 ng/mL. For those with a PSA level from 4.1 to 10.0 ng/mL, and negative DRE and TRUS findings, biopsy was indicated only when PSA density (PSAD) was greater than 0.15. The same indication was applied for the repeat biopsy.
Results: A repeat biopsy after an interval of more than 2 years was carried out in 140 patients and was positive in 50 (36%) patients. The PSA value at the diagnosis of cancer declined from the initial value in six (12%) patients. On multivariate logistic regression analysis, PSA velocity (PSAV) as well as PSAD and DRE findings at latest screening were independent predictors for positive repeat-biopsy outcome. The odds ratio (95% confidence intervals) of PSAV >0.48, latest PSAD >0.33 and positive latest DRE were 4.17 (1.05-18.5), 4.15 (1.31-14.0), and 3.62 (1.06-13.2), respectively. A combination of three variables defined as positive if any of these were positive, reduced 31% of unnecessary biopsies while missing 8% of low volume, low grade cancers.
Conclusions: A combination of latest PSAD, PSAV and positive DRE at latest screening might help to reduce unnecessary repeat biopsies in high-risk patients with an initial negative biopsy.