Performing salvage robot-assisted radical prostatectomy (S-RARP) following focal therapy for prostate cancer (PCa) results in “acceptable” complication rates, according to investigators. But patients who undergo focal therapy and then delayed surgery might experience higher rates of biochemical recurrence and erectile dysfunction.
Igor Nunes-Silva, MD, and colleagues of Institut Mutualiste Montsouris at Université Paris-Descartes in Paris, reported these results in The Journal of Urology after comparing outcomes from 22 of their patients who had S-RARP after focal therapy failure during 2000–2016 and 44 matched controls who had RARP for primary treatment (P-RARP). Patients permitted focal therapy had localized PCa (specifically Gleason score 3+3 or 3+4, clinical stage T2a or lower, serum PSA 15 ng/mL or below, and less than 10 mm of cancer in any biopsy core) and a life expectancy longer than 10 years. Urologists performed targeted ablation of the index lesion, identified with multiparametric magnetic resonance imaging, including a 1-cm margin of safety. Tumor location and the institution’s guidelines governed the use of high-intensity focused ultrasound, cryotherapy, brachytherapy, vascular-targeted photodynamic therapy, or laser ablation with the drug WST11.
Overall complication rates were similar between primary and salvage RARP groups. High-grade complications occurred in a few S-RARP patients.
Continence, measured by pad-free probability, also was comparable for the S-RARP and P-RARP groups (49.5% vs 62.4% at 1 year and 73% vs 76.5% at 2 years after surgery, respectively). Potency recovery was significantly worse for S-RARP patients, according to IIEF-5 scores: “In this context, focal therapy seemed to negatively affect erectile recovery,” Dr Nunes-Silva and the team noted. “This effect is likely related either to the focal therapy energy applied directly to the prostate or to the higher number of prostate biopsies these patients underwent during focal therapy follow-up before S-RARP.” Only 2 patients had a second focal therapy ablation before S-RARP.
According to the investigators, bilateral nerve-sparing (NS) occurred less with S-RARP, possibly indicating that nerve-bundle tissues had a degree of impairment preventing optimal preservation. “These findings indicate that focal therapy does not completely compromise surgical anatomic status and does not limit subsequent salvage surgery if necessary, although the quality of nerve-sparing should be considered.”
With regard to oncologic outcomes, overall biochemical recurrence (BCR) rates were similar but the S-RARP group experienced quicker recurrence and had a significantly lower probability of BCR-free survival (67.6% vs 95.1% at 1 year and 56.3% vs 92.4% at 2 years). BCR risk was 4.8 times higher with S-RARP.
The investigators believe their findings support focal therapy as an experimental treatment within clinical trials for appropriate patients who are closely monitored for focal therapy failure and receive prompt salvage treatment. Future research identifying risk factors for focal therapy failure would aid management.
Nunes-Silva I, Barret E, Srougi V, et al. Effect of Prior Focal therapy on perioperative, oncologic and functional outcomes of salvage robotic assisted radical prostatectomy. J Urol. doi: 10.1016/j.juro.2017.05.071