In his latest published research, Dr. Rob Olson radiation oncologist and research lead at BC Cancer and UBC Northern Medical Program associate professor, found patient side effects from an innovative cancer treatment that delivers higher doses of radiation over less treatments can be minimized, while still remaining effective at controlling cancer spread, through his SABR-5 trial.
The treatment, known as SABR, is a form of high-precision cancer therapy that delivers substantially higher doses of radiation to tumour sites in just one or a few treatment sessions. Olson is leading the follow up ongoing phase III international trial titled SABR-COMET-3 investigating whether this treatment can improve the survival of, and potentially cure, certain patients.
“An earlier, smaller phase II trial in 2019, called SABR-COMET, showed encouraging results with people living two times longer than those who did not receive the treatment,” said Dr. Olson. “However, there was three times the rate of side effects in those who received SABR, including a 30 per cent rate of mild side effects (for example pain), an approximately 15 per cent rate of serious side effects (for example requiring hospitalization), and 5 per cent rate of death from side effects. Therefore, we wanted to test if we could deliver SABR in a safer, yet equally effective manner with our SABR-5 trial.”
“We specifically sought to determine if a large, coordinated provincial program, with several quality and safety mechanisms in place, could keep the side effect rate very low. We had also wanted to demonstrate that SABR can be safe, while still achieving high rates of tumour control, before we moved on to the larger SABR-COMET-3 randomized trial that we are currently running internationally from Prince George.”
The SABR-5 trial specifically looked at the effects of SABR treatment as provided to patients whose cancer had spread from the original location (e.g. prostate, lung) to as many as five new sites (e.g. bone, liver).
“This research is important as it showed that in a coordinated program with safety checks in place, the side effects from SABR are low (less than 5 per cent rate of serious side effects and a 0.3 per cent death rate from side effects), and the control of the cancer spread is high (90 per cent at 1 year),” noted Dr. Olson. “This trial also gave specific information on which body parts required more caution and study when treating, such as the liver and adrenal glands.”
The study, "Treatment with Stereotactic Ablative Radiotherapy for Up to 5 Oligometastases in Patients with Cancer - Primary Toxic Effect Results of the Nonrandomized Phase 2 SABR-5 Clinical Trial", was recently published in
JAMA Oncology, an international peer-reviewed medical journal.
“This study, and the current SABR-COMET-3 trial, are run from the BC Cancer – Prince George centre,” added Dr. Olson. “We are currently planning for a new, even larger international clinical trial to follow, which is a complex process as such large trials are not funded by standard government operating funds and require grant funding and community donation support.”
The current SABR-COMET-3 trial is supported through funding from the Canadian Institutes for Health Research, Varian Medical Systems, and the BC Cancer Foundation.
This article has been adapted. Read the original story on the UNBC website.
