Prostate-Only Versus Whole-Pelvic Radiation Therapy in High-Risk and Very High-Risk Prostate Cancer (POP-RT): Outcomes From Phase III Randomised Controlled Trial - PDF Version
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
We report the clinical outcomes of a randomised trial comparing prophylactic whole-pelvic nodal radiotherapy to prostate-only radiotherapy (PORT) in high-risk prostate cancer.
This phase III, single center, randomised controlled trial enrolled eligible patients undergoing radical radiotherapy for node-negative prostate adenocarcinoma, with estimated nodal risk ≥ 20%. Randomisation 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 computerised stratified block randomisation, 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 two years of androgen deprivation therapy. The primary end point was five-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 five-year DFS (89.5% v 77.2%; HR, 0.40; 95% CI, 0.22 to 0.73; P = .002), but five-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.