Enhancement of HIFU Effect by Simultaneous Short Course Degarelix for Early Stage Prostate Cancer: A Pilot Study

Abstract

Objective: To obtain complete prostatic cell death in the treatment of early stage prostate cancer by High Intensity Focused Ultrasound (HIFU) therapy, we use Degarelix (GnRH antagonist) twice simultaneously. Patients and Methods: The first Degarelix subcutaneous injection was made two weeks before HIFU therapy, and second Degarelix was applied two weeks after the HIFU therapy. No additional maintenance Degarelix was used. To confirm the apoptosis induced by Degarelix, specimens obtained by transurethral resection simultaneously on HIFU were stained with caspase 3 and TUNEL. PSA was monitored every three months after this combination therapy as long as two years. These PSA values were compared with those who previously treated with HIFU without Degarelix. Results: Nine T1cN0M0 prostate cancer patients were enrolled to “HIFU + Degarelix” therapy. Pre treatment mean PSA level was 6.11 ± 1.83 ng/ml (SD), and PSA 3 months after the treatment was 0.02 ± 0.02. These low PSA levels continued thereafter (0.16 ng/ml ± 0.19 at 24 months). The mean pretreatment PSA level of the 34 patients underwent HIFU without Degarelix was 11.07 ± 13.9 ng/ml, 3 months post HIFU was 1.68 ± 3.04, (2.80 ± 3.97 at 24 months). Caspase 3 and TUNEL were positive on the glandular cells in TUR specimens of “HIFU + Degarelix” patients, suggesting Degarelix induced apoptosis. Conclusion: Although the number of our patients was small, the results of “Short course Degarelix + HIFU” would be promising for better long-term outcome than HIFU mono-therapy.