Prostate cancer focal therapy: surgeon experience influences oncological results

Abstract

Introduction: Characterization of the index lesion of prostate cancer (PCa) has facilitated the development of focal therapy to reduce complications caused by radical treatments. In the present study, we sought to identify factors associated with the oncological results of focal therapy for PCa.

Methods: Between April 2017 and February 2020, 123 PCa patients received focal therapy performed with high-intensity focused ultrasound (HIFU). The patients presented unilateral localized disease, PSA < 20 ng/dl, clinical stage T1-T2, ISUP grade 1-3, and more than 10 years of life expectancy. Five certified surgeons with different levels of experience performed the procedures and were divided into groups #1 and #2 (>30 HIFUs performed) and #3 (10-15 HIFUs performed each). All patients were prospectively followed and underwent surveillance biopsy 1 year post-treatment. The primary endpoint was radical treatment, and secondary endpoints included focal therapy failure and in-field recurrence. Univariate and multivariate logistic regression were used to detect associations between clinical and procedure variables and the endpoints.

Results: The median follow-up was 54.3 months, with a mean age of 64.4 years. The mean PSA was 6.6 ng/dl; 59.3% of patients had intermediate-risk disease, and the remaining had low-risk. During follow-up, 29 (23.6%) patients required radical treatment (external beam radiation therapy), 37 (30.1%) experienced treatment failure, and 26 (21.1%) had an in-field recurrence with an ISUP grade of ≥2. Radical treatment in the follow-up was associated with patients treated by surgeons in group #3 and with elevated post-HIFU PSA concentrations. Baseline PSA concentrations, group #3 surgeons, and post-HIFU PSA concentrations were associated with treatment failure. In-field positive biopsies were associated with baseline and post-HIFU PSA concentrations. Furthermore, patients treated by surgeons in group #3 were independently associated with radical treatment and focal therapy failure.

Conclusion: Focal therapy with HIFU has acceptable oncological outcomes in the medium term, and the surgeon's experience and technique are independently associated with the need for subsequent radical treatment and focal therapy failure.

Keywords: focal therapy; high‐intensity focused ultrasound; oncological outcomes; prostatic neoplasm.