Randomized Trial of Transperineal Versus Transrectal Prostate Biopsy to Prevent Infection Complications.

261 Background: Transrectal prostate biopsy is the predominant approach to prostate cancer detection in the U.S. and worldwide. The transperineal approach is traditionally preformed under general anesthesia. Recent advances enable prostate biopsy to be performed through the skin of the perineum (transperineal) under local anesthesia. There are potential advantages to this clean, percutaneous approach over the inherently contaminated transrectal approach. However, comparative evidence is limited. Methods: In a multicenter, randomized trial, we used two-stage consent and assigned participants with suspicion for prostate cancer to undergo transperineal biopsy without antibiotic prophylaxis vs. transrectal biopsy with targeted prophylaxis. The primary outcome was post-biopsy infection, with secondary outcomes of urinary retention, significant bleeding, cancer detection, and a numerical rating scale (0-10) for biopsy-related pain and discomfort during 7-days post-biopsy. Results: Six-hundred fifty-eight participants underwent randomization, and 567 (86%) of participants were included in the intent to treat analysis. Seventy-nine men declined to participate. There were zero transperineal versus 4 (1.4%) transrectal biopsy infections (adjusted difference -1.4%; 95% confidence interval -3.2, 0.3; P=0.059). Rates of other complications were very low and similar by approach. Importantly, detection of clinically significant cancer was similar (53% transperineal vs. 50% transrectal, adjusted difference 2.0%; 95% CI -6.0, 10; p=0.6). Participants undergoing transperineal biopsy experienced worse periprocedural pain (0.6 adjusted difference [0-10 scale] 95% CI 0.2, 0.9; P=0.002), but the effect was small and resolved by 7-days. Conclusions: Office-based transperineal biopsy is tolerable, does not compromise cancer detection and likely reduces the risk of infection without antibiotic prophylaxis, thereby improving antibiotic stewardship. Altogether, our findings support office based transperineal prostate biopsy without antibiotic prophylaxis as the new standard of care for prostate cancer detection with per patient and population-based antibiotic stewardship and healthcare cost benefits. Finally, two-stage consent facilitates accrual for surgical randomized trials, as evidenced by the relatively low rate of participants declining and withdrawing from the trial. Clinical trial information: NCT04815876 .