Prospective Study on the Role of Radical Prostatectomy in Oligo-metastatic Hormone-sensitive Prostate Cancer in Patients on Androgen Deprivation Therapy

Radical prostatectomy is being investigated as a cytoreductive treatment in selected men with oligometastatic hormone-sensitive prostate cancer who respond to androgen-deprivation therapy (ADT). MAZINGA is a prospective, single-centre, single-group pilot study designed to obtain preliminary estimates of survival and treatment response after the addition of radical prostatectomy to ongoing ADT. Eligible participants have acinar prostate adenocarcinoma, no more than five bone metastases confined to the spine and/or pelvis, no visceral or retroperitoneal nodal metastases, no bulky pelvic nodes greater than 3 cm, an Eastern Cooperative Oncology Group performance status of 0 or 1, and a PSA level below 4 ng/mL after at least 6 months of ADT. Participants undergo robot-assisted laparoscopic radical prostatectomy with modified extended bilateral pelvic lymph-node dissection. ADT is continued according to the treating oncologist. PSA and serum testosterone are measured at months 1 and 3 and every 3 months thereafter through month 24. Contrast-enhanced computed tomography of the chest and abdomen plus whole-body bone scintigraphy are performed every 6 months through month 24; PSMA PET may be used instead according to the imaging modality used at staging and clinical judgment. EPIC-CP and IPSS questionnaires are administered at months 3 and 12. After month 24, survival status is assessed every 6 months. The planned convenience sample is 30 participants. Baseline characteristics and biomarker data are summarised descriptively, and survival outcomes are estimated using Kaplan-Meier methods. Radiological response is planned to be assessed according to RECIST version 1.1; the operational definition across the permitted imaging modalities must be confirmed before release.