Prostate RT improves overall survival in men with newly diagnosed, low-burden metastatic prostate cancer

UK: In men with newly diagnosed, low-burden metastatic prostate cancer, Prostate radiotherapy RT improves overall survival (OS), without detriment in quality of life( QoL), states long-term results from the STAMPEDE randomised controlled trial published in PLOS Medicine. This indicates that Prostate RT should be recommended as a standard of care( SOC).

Recent reports show more than 1.4 million new prostate cancer cases are diagnosed globally. About 50% of men diagnosed with local prostate cancer will get metastatic cancer during their lifetime. early diagnosis and treatment can lower this rate. Prostate radiotherapy (RT) is recommended for men with newly diagnosed, low-burden, metastatic prostate cancer, but not for men with the high-burden disease.

Chris C, The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, London and team hypothesised that prostate RT would reduce the complications of local disease progression, such as urinary or bowel obstruction and this could benefit men with metastatic disease, regardless of disease burden. Any benefits of prostate RT need to be weighed against the risk of treatment-related adverse events (AEs).

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

For the study patients were randomised at secondary care sites in the United Kingdom and Switzerland (January 2013 - September 2016), with a 1:1 stratified allocation: 1,029 to SOC and 1,032 to SOC+RT. A total of 1,939 had metastatic burden classifiable, with 42% low burden and 58% high burden, balanced by treatment allocation. Prospectively collected patient responses to the QLQ-30 questionnaire were used to assess QoL in the first 2 years of the trial. Patients were followed for a median of 61.3 months

Data analysis showed that,

• Prostate RT improved OS in patients with low, but not high, metastatic burden (respectively: 202 deaths in SOC vs. 156 in SOC+RT, HR = 0•64, p < 0.001; 375 SOC vs. 386 SOC+RT, HR = 1.11, p = 0•164; p < 0.001).

• No evidence of a difference in time to symptomatic local events was found.

• There was no evidence of a 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.

From the final analysis, researchers have confirmed that prostate RT improves overall survival in men with newly diagnosed, low-burden metastatic prostate cancer, but not in men with the high-burden disease. The magnitude of the survival benefit is considerable and clinically relevant, especially since prostate RT is a relatively cheap, widely accessible, and well-tolerated treatment.

Data suggests freedom from local interventions (e.g., urinary catheters, ureteric stents, nephrostomies, and colostomy),) the authors wrote.

Parker CC, James ND, Brawley CD, Clarke NW, Ali A, Amos CL, Attard G et al.  STAMPEDE Trial Collaborative Group. Radiotherapy to the prostate for men with metastatic prostate cancer in the UK and Switzerland: Long-term results from the STAMPEDE randomised controlled trial. PLoS Med. 2022 Jun 7;19(6):e1003998. doi: 10.1371/journal.pmed.1003998.