Definitive Therapy of Early Prostate Cancer with Transurethral MicrowaveThermotherapy after Prostate Volume Reduction by Androgen Deprivation: A17-Year Experience of a Potential Alternative to Radical Surgery

Background: Transurethral Microwave Thermotherapy (TUMT) has shown limited efficacy as a treatment for prostate cancer, mainly because of the inability of microwaves to reach the peripheral region of the prostate. Pretreatment with Androgen Deprivation Therapy (ADT) may increase TUMT efficacy by reducing the prostate size. Objective: To examine the clinical outcomes of patients undergoing TUMT after at least 3 months of ADT. Design, setting, and participants: One hundred twenty-three men with early, non-metastatic prostate cancer and Prostate-Specific Antigen (PSA) levels of 4.0 ng/mL or higher were enrolled between 2001 and 2011 and followed up until 2017. TUMT was performed after at least 3 months of ADT and the efficacy of this treatment was confirmed by radical Transurethral Resection of the Prostate (TURP) performed at least 3 months after TUMT. Intervention: ADT and TUMT, Outcome Measurements and Statistical Analysis, Post-intervention prostate volume, presence of remnant cancer cells, and clinical outcomes. Results and limitations: Prostate volume was significantly reduced (mean, 35.2%) after 3 months of ADT. Histopathological examination of TURP chips revealed no cancer cells in 102 of 123 patients. Twenty-one patients demonstrated remnant cancer cells; in 13 patients these were non-viable, and in 8 they were degraded. During the 17- year follow-up period, 28 patients received regular or intermittent anti-androgen therapy to maintain PSA levels below 4.0 ng/mL. No patients died of prostate cancer. Conclusion: Combination ADT and TUMT therapy in 123 patients suggests that early prostate cancer is easily destroyed by heat. A significant reduction of prostate volume after ADT increased TUMT efficacy in the peripheral zone and apex. Patient summary: In this study, ADT reduced the volume of the prostate gland by around 35%, enhancing the ability of TUMT to kill cancer cells. This approach should be further evaluated as a less-invasive alternative to current, conventional therapies.