Prostate-Only Versus Whole-Pelvic Radiation Therapy in High-Risk and Very High-Risk Prostate Cancer (POP-RT): Outcomes From Phase III Randomized Controlled Trial.

We report the clinical outcomes of a randomized trial comparing prophylactic whole-pelvic nodal radiotherapy to prostate-only radiotherapy (PORT) in high-risk prostate cancer.

This phase III, single center, randomized controlled trial enrolled eligible patients undergoing radical radiotherapy for node-negative prostate adenocarcinoma, with estimated nodal risk ≥ 20%. Randomization was 1:1 to PORT (68 Gy/25# to prostate) or whole-pelvic radiotherapy (WPRT, 68 Gy/25# to prostate, 50 Gy/25# to pelvic nodes, including common iliac) using computerized stratified block randomization, stratified by Gleason score, type of androgen deprivation, prostate-specific antigen at diagnosis, and prior transurethral resection of the prostate. All patients received image-guided, intensity-modulated radiotherapy and minimum 2 years of androgen deprivation therapy. The primary end point was 5-year biochemical failure-free survival (BFFS), and secondary end points were disease-free survival (DFS) and overall survival (OS).

From November 2011 to August 2017, a total of 224 patients were randomly assigned (PORT = 114, WPRT = 110). At a median follow-up of 68 months, 36 biochemical failures (PORT = 25, WPRT = 7) and 24 deaths (PORT = 13, WPRT = 11) were recorded. Five-year BFFS was 95.0% (95% CI, 88.4 to 97.9) with WPRT versus 81.2% (95% CI, 71.6 to 87.8) with PORT, with an unadjusted hazard ratio (HR) of 0.23 (95% CI, 0.10 to 0.52; P < .0001). WPRT also showed higher 5-year DFS (89.5% v 77.2%; HR, 0.40; 95% CI, 0.22 to 0.73; P = .002), but 5-year OS did not appear to differ (92.5% v 90.8%; HR, 0.92; 95% CI, 0.41 to 2.05; P = .83). Distant metastasis-free survival was also higher with WPRT (95.9% v 89.2%; HR, 0.35; 95% CI, 0.15 to 0.82; P = .01). Benefit in BFFS and DFS was maintained across prognostic subgroups.

Prophylactic pelvic irradiation for high-risk, locally advanced prostate cancer improved BFFS and DFS as compared with PORT, but OS did not appear to differ.

Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 2021 Jan 26 [Epub ahead of print]

Vedang Murthy, Priyamvada Maitre, Sadhana Kannan, Gitanjali Panigrahi, Rahul Krishnatry, Ganesh Bakshi, Gagan Prakash, Mahendra Pal, Santosh Menon, Reena Phurailatpam, Smruti Mokal, Dipika Chaurasiya, Palak Popat, Nilesh Sable, Archi Agarwal, Venkatesh Rangarajan, Amit Joshi, Vanita Noronha, Kumar Prabhash, Umesh Mahantshetty

Department of Radiation Oncology, Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India., Clinical Research Secretariat, Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India., Department of Surgery, Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India., Department of Pathology, Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India., Department of Medical Physics, Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India., Department of Radiodiagnosis, Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India., Department of Nuclear Medicine and Molecular Imaging, Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India., Department of Medical Oncology, Tata Memorial Hospital and Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Homi Bhabha National Institute (HBNI), Mumbai, India.