Prostate-specific antigen kinetics contributes to decision making for biopsy referral: the predictive implication for PSA retest in patients with elevated PSA levels.

Background: It is common to repeat prostate-specific antigen (PSA) measurements for men with PSA elevation before prostate biopsy. In this scenario, they may have considerable psychological distress in fear of the presence of cancer until retests. We assessed possible clinical factors causing transient PSA rise and explored the parameters predictive of subsequent PSA change. Methods: As interfering conditions, the history of ejaculation, bicycling, and any types of infections were assessed using the questionnaire. The pattern of PSA change was compared in association with the various clinical factors. Predictive significance of PSA kinetics such as coefficient of variation (CV) and PSA velocity (PSAV) for PSA values at retest was evaluated. Results: The rate of reversion to the normal range was 38.3% at retest. The rate of 12.8% of men showed a large increase by ≥20%, whereas 38.2% of men showed a large decline by ≥20% from the baseline. Men with younger age (≤60 years), small prostate (<20 cc), and prior history of ejaculation or infections showed significantly larger PSA decrease than their counterparts. Those with large CV or PSAV before the baseline more frequently showed PSA decrease below the age-specific cutoff or decline by ≥10% from the baseline at retest. These parameters associated with PSA kinetics had independent predictive values for relevant PSA change at retest. Conclusions: Ejaculation and any types of infections should be avoided before PSA tests. Men with large PSA fluctuation before the baseline are likely to show a significant PSA decrease at retest. This predictive information may help both physicians to determine whether to proceed to an immediate biopsy and patients to reduce their psychological burden.