Clinical significance of the De Ritis ratio for detecting prostate cancer in a repeat prostate biopsy

We evaluated factors predicting a positive repeat biopsy result in patients with an initial negative prostate biopsy result. This study included 124 patients in whom prostate cancer (PCa) was not detected in the initial transrectal ultrasound-guided prostate biopsy and who underwent repeat biopsy from January 2011 to December 2017. Patients without PCa in both initial and repeat prostate biopsies were designated as group 1 (n=82), and those in whom PCa was detected on a repeat prostate biopsy were designated as group 2 (n=42). Among group 2 patients, 6 had insignificant PCa according to the Epstein criteria and were combined with group 1 patients to make up group A (n=88). Patients with significant PCa were categorized as group B (n=36). We compared clinicopathologic characteristics between the groups. Multivariate analysis showed that age (p=0.018) and detection of atypical small acinar proliferation (ASAP) or ≥3 cores of high-grade prostatic intraepithelial neoplasia (HGPIN) (p=0.011) on the initial biopsy were predictive factors for a positive result on a repeat biopsy. When we compared group A and group B, age (p=0.004) and the De Ritis ratio (p=0.024) were significantly higher in group B in the multivariate analysis. Age and the detection of ASAP or ≥3 cores of HGPIN on the initial biopsy were associated with detection of PCa on a repeat biopsy. Age and the De Ritis ratio were found to be predictive factors for the detection of clinically significant PCa on a repeat biopsy.