Promise of novel radiation treatment for metastatic cancer patients
A study co-led by BC Cancer researchers has found that the use of stereotactic ablative radiotherapy (SABR) technology may improve survival rates for patients with limited metastatic cancer. The findings are the result of the world’s first randomized clinical trial of SABR as it relates to cancer that has already spread to other parts of the body. SABR technology is a highly precise form of radiotherapy where much higher doses of radiation can be safely delivered to tumors over a shorter time period. The technology features advanced machines with built-in CT scans that can sculpt the dose of radiation to tumors from multiple angles while reducing the dose to healthy nearby tissue.
Until now, there was not much evidence to support the claim that patients with a small number of additional tumors could be cured of the disease once all growths are killed with radiation. The SABR-COMET trial aimed to assess the effect of SABR on survival, outcomes, toxicity, and quality of life in patients with a controlled primary tumor and one to five additional tumors.
During the randomized trial, which took place over 4 years at 10 centres worldwide (including all six BC Cancer centres), the patient group who was treated with SABR technology saw an overall improvement in survival. However, there is a possibility of serious side effects, so future research is needed to confirm its efficacy.
Phase III trials are needed to conclusively show an overall survival benefit and to determine the number of metastatic tumors that could benefit from SABR treatment.
The study was led at BC Cancer by Dr Robert Olson, radiation oncologist, along with an international team of researchers. The results will open the door for patients in the upcoming trial, titled SABR-COMET-3, a Phase III randomized controlled trial for patients across the province with one to three metastatic tumors; that trial is being led by Dr Olson from BC Cancer, Prince George.
The article, “Stereotactic ablative radiotherapy versus standard of care palliative treatment in patients with oligometastatic cancers (SABR-COMET): A randomised, phase 2, open-label trial,” was published in The Lancet. It is available at www.thelancet.com/journals/lancet/article/PIIS0140-6736%2818%2932487-5/fulltext.