Evaluating efficacy of targeted microwave ablation in patients with prostate cancer: A systematic review and proportional meta-analysis.

Abstract

e17133 Background: Prostate cancer (PC) remains one of the most prevalent malignancies affecting men worldwide. Targeted focal therapies have helped ablate the tumor, thus reducing the tumor burden. Of these therapies, microwave ablation, employing microwaves for thermal ablation of the tumor, has been gaining recent focus. This systematic review and meta-analysis aims to assess the efficacy of targeted microwave ablation in patients with newly diagnosed PC. Methods: A comprehensive literature search was conducted across five databases to identify trials evaluating patient outcomes and adverse events following targeted microwave ablation. Data was extracted as the number of events, quantified as odd’s ratio and 95% confidence interval (CI) for dichotomous variables and mean and standard deviation for continuous variables. Analysis was performed using a generalized linear mixed-effects model for proportional-meta-analysis in R employing a random effects model. Results: A total of 8 trials comprising 222 patients with diagnosed prostate cancer were evaluated for further quantitative synthesis. The incidence of perioperative complications was low, occurring in only 13% of the patients undergoing microablative coagulation [95%CI: 0.03, 0.46]. However, incidence varied significantly across studies, which could be due to the different systems used for ablation or the stage and grade of prostate cancer in patients; notably, the incidence of perioperative complications was lesser on employing a transrectal approach, and among those with advanced stage of prostate cancer. Following the procedure, a reduction in prostate-specific antigen (PSA) was recorded in 83% of the cases [95%CI 0.37, 0.98], implying a high immediate success rate of ablation. PSA levels post-operatively were 14.83 ng/ml [95% CI: 1.77, 27.9]. The clinical response rate was high, noted in over 77% of the patients [95% CI: 0.53, 0.91]. However, progressive disease was also considerably high, recorded in 26% of the patients [95%CI: 0.18, 0.38]. 26% of the patients reported adverse events following the procedure (26% [95%CI: 0.12, 0.49]), and a majority of these unfavorable events were of grades 1-2 (17% [95%CI: 0.05, 0.44]). Conclusions: The preliminary results suggest a high response of patients to focal microablative therapy. A high PSA reduction rate and clinical response rate imply immediate response of patients to the treatment. However, the incidence of adverse events may be of concern. A low perioperative complication rate suggests the overall safety of the procedure. However, these findings must be evaluated against standard therapies like resection and cryoablation. While preliminary single-armed trials highlight the efficacy of microablation, future studies should employ a multi-arm trial design, evaluating the comparative efficacy of microablation vis-à-vis other focal therapies.