This was a trial of prostate radiotherapy in men with metastatic prostate cancer. Up until now these men have always been treated with drug therapy alone and we’ve tested the effect of treating the prostate with radiotherapy on survival. It was a trial of 2,000 patients randomised one to one between standard drug treatment only or standard drug treatment plus radiotherapy. Overall there was no significant difference in overall survival, however, in patients with a low metastatic burden there was a significant survival benefit with a hazard ratio of 0.68 and the absolute benefit at three years was 8% and radiotherapy was very well tolerated.
The overall survival at three years, if we just go over the figures there, from 73% up to 81% was it?
That’s correct, yes. So overall survival at three years in patients with a low metastatic burden was improved from 73% to 81%.
And any quick thoughts on where that threshold between low metastatic and high metastatic burden could be refined to find out just who this could be the best treatment for?
That’s a good question. We used the CHAARTED criteria for allocating patients to high or low metastatic burden but there’s no reason to think that’s the optimum classification and we will be doing exploratory work on our data to see if we can work out precisely who benefits and who doesn’t benefit.
Any other follow-ups we should be on the watch for?
Going forward prostate radiotherapy will now be a standard treatment option for men with a low metastatic burden. The next research question that we’re going to be asking in this population is whether there’s a further benefit from giving radical radiotherapy to oligometastasis in these very same patients.