Radiotherapy to the prostate for men with metastatic prostate cancer in the UK and Switzerland: Long-term results from the STAMPEDE randomised controlled trial
Authors: Parker Chris C. , James Nicholas D. , Brawley Christopher D. , Clarke Noel W. , Ali Adnan , Amos Claire L. , Attard Gerhardt , Chowdhury Simon , Cook Adrian , Cross William , Dearnaley David P. , Douis Hassan , Gilbert Duncan C. , Gilson Clare , Gillessen Silke , Hoyle Alex , Jones Rob J. , Langley Ruth E. , Malik Zafar I. , Mason Malcolm D. , Matheson David , Millman Robin , Rauchenberger Mary , Rush Hannah , Russell J Martin , Sweeney Hannah , Bahl Amit , Birtle Alison , Capaldi Lisa , Din Omar , Ford Daniel , Gale Joanna , Henry Ann , Hoskin Peter , Kagzi Mohammed , Lydon Anna , O’Sullivan Joe M. , Paisey Sangeeta A. , Parikh Omi , Pudney Delia , Ramani Vijay , Robson Peter , Srihari Narayanan Nair , Tanguay Jacob , Parmar Mahesh K. B. , Sydes Matthew R. ,   for the STAMPEDE Trial Collaborative Group
Published: June 2022

Background

STAMPEDE has previously reported that radiotherapy (RT) to the prostate improved overall survival (OS) for patients with newly diagnosed prostate cancer with low metastatic burden, but not those with high-burden disease. In this final analysis, we report long-term findings on the primary outcome measure of OS and on the secondary outcome measures of symptomatic local events, RT toxicity events, and quality of life (QoL).

Methods and findings

Patients were randomised at secondary care sites in the United Kingdom and Switzerland between January 2013 and September 2016, with 1:1 stratified allocation: 1,029 to standard of care (SOC) and 1,032 to SOC+RT. No masking of the treatment allocation was employed. A total of 1,939 had metastatic burden classifiable, with 42% low burden and 58% high burden, balanced by treatment allocation. Intention-to-treat (ITT) analyses used Cox regression and flexible parametric models (FPMs), adjusted for stratification factors age, nodal involvement, the World Health Organization (WHO) performance status, regular aspirin or nonsteroidal anti-inflammatory drug (NSAID) use, and planned docetaxel use. QoL in the first 2 years on trial was assessed using prospectively collected patient responses to QLQ-30 questionnaire.

Patients were followed for a median of 61.3 months. Prostate RT improved OS in patients with low, but not high, metastatic burden (respectively: 202 deaths in SOC versus 156 in SOC+RT, hazard ratio (HR) = 0·64, 95% CI 0.52, 0.79, p < 0.001; 375 SOC versus 386 SOC+RT, HR = 1.11, 95% CI 0.96, 1.28, p = 0·164; interaction p < 0.001). No evidence of difference in time to symptomatic local events was found. There was no evidence of difference in Global QoL or QLQ-30 Summary Score. Long-term urinary toxicity of grade 3 or worse was reported for 10 SOC and 10 SOC+RT; long-term bowel toxicity of grade 3 or worse was reported for 15 and 11, respectively.

Conclusions

Prostate RT improves OS, without detriment in QoL, in men with low-burden, newly diagnosed, metastatic prostate cancer, indicating that it should be recommended as a SOC.

Trial registration

ClinicalTrials.gov NCT00268476, ISRCTN.com ISRCTN78818544.