Predictive Factors of Prostate Cancer at Repeat Biopsy in Patients with an Initial Diagnosis of Atypical Small Acinar Proliferation of the Prostate

PURPOSE: The factors that predict prostate cancer detection on repeat biopsy were evaluated in patients with atypical small acinar proliferation (ASAP) on the initial biopsy. MATERIALS AND METHODS: From 2003 to 2008, 3,130 men with suspected prostate cancer underwent a prostate needle biopsy, and 244 (7.8%) were diagnosed as having ASAP. One hundred seventy of 244 patients were rebiopsied at least once more. They were classified into a prostate cancer group and a noncancer group according to the final pathological diagnosis. The database of rebiopsied patients included age, initial prostate-specific antigen (PSA), PSA density (PSAD), PSA velocity (PSAV), total prostate volume (TPV), and transitional zone volume of the prostate (TZV). We compared differences in the aforementioned parameters between the 2 groups. RESULTS: A total of 57 patients (33.5%) with ASAP were ultimately shown to have prostate cancer. Univariate analysis showed that PSAD (p=0.002), PSAV (p=0.001), TPV (p=0.035), and TZV (p=0.005) differed significantly between the cancer and noncancer groups. The results of the multivariate analysis showed that PSAD (p=0.022), PSAV (p<0.001), and TPV (p=0.037) had a statistically significant correlation with cancer detection. CONCLUSIONS: PSAD, PSAV, and TPV are predictive factors of prostate cancer in patients with an initial diagnosis of ASAP of the prostate. Although repeat biopsy is mandatory irrespective of PSA values, the follow-up of PSA may help to estimate the probability of cancer in these men.