Transperineal versus transrectal prostate biopsy for predicting the final laterality of prostate cancer. Are they reliable enough to select patients for focal therapy? Results from a multicenter international study

Objectives: To compare the concordance of prostate cancer (PCa) laterality between the extended transperineal (TP) or transrectal (TR) prostate biopsy (BP) and radical prostatectomy (RP) specimens. To identify predictors of laterality agreement between BP and RP. Materials and Methods: Data from 533 consecutive patients with PCa (278 TP and 255 TR-diagnosed) treated with RP were analyzed. A 12-core technique was used for both TP and TR biopsies. Additional cores were obtained when necessary. Results: Overall, the percentage of agreement of PCa laterality between BP and RP was 60% (K = 0.27, p < 0.001). However, the RP confirmation of unilaterality at BP was obtained in just 33% of the cases. Considering the concordance on bilaterality as the "target" of our analysis, the sensitivity and specificity were 54.3% and 98.2%, respectively, with TP and 47.5% and 92.5%, respectively with TR. Focusing on patients with unilaterality at biopsy, none of the evaluated preoperative variables (biopsy technique, age, total positive biopsy cores, PSA, prostate volume, Gleason score on biopsy) were able to predict RP bilaterality in the multivariate analyses. Conclusions: Most of the patients with unilateral involvement at BP harbored bilateral PCa after RP. TR and TP biopsy showed no difference in their capacity to predict the concordance of tumor laterality at RP. None of the preoperative evaluated variables can predict the tumor laterality at RP. Using BP unilaterality to include patients in focal therapy (FT) protocols may hinder the oncologic efficacy of FT.