Role of prostate-specific antigen change ratio at initial biopsy as a novel decision-making marker for repeat prostate biopsy

Purpose: Prostate biopsy is used to confirm the prostate cancer. Although first biopsy result was benign, repeat biopsy is recommended for the patient who has higher risk of prostate cancer. In this study, we investigated the PSA change ratio (post-biopsy PSA to baseline PSA) whether it could be predictive factor of prostate cancer and helpful when decided to perform repeat biopsy. Materials and Methods: 151 patients, first diagnosed as benign, but underwent repeat biopsy due to clinical suspicion of prostate cancer were included. Post-biopsy PSA was checked 60 minutes later after biopsy. PSA change ratio was defined as post-biopsy PSA to baseline PSA. According to results of repeat biopsy, patients were divided into benign group (group A) and cancer groups (group B). Between two group baseline PSA, PSA density, post-biopsy PSA and PSA change ratio were compared, and most effective cut-off value was analyzed using receiver operating characteristic (ROC). Results: 129 men were benign, 22 men were prostate cancer according to results of repeat biopsy. Between two groups, post-biopsy PSA and PSA change ratio were statically significant differences. (p<0.001, <0.001) The effective cut-off value was 3.0, 3.5 and 4.0 according to ROC. At ROC curve, PSA change ratio was statistically significant for diagnosis of prostate cancer. (AUC 0.800, p<0.001). Conclusions: PSA change ratio is thought be a predictive factor for prostate cancer. If the PSA change ratio was less than 3.0-4.0, repeat biopsy should be considered to confirm the diagnosis.