Radioembolization Safe and Effective in Patients with Unresectable mCRC
Interview with Dr. Andrew Kennedy - Sarah Cannon Research Institute, Nashville, TN
Radioembolization with yttrium-90 microspheres (90Y-RE) appears to have a favorable risk to benefit profile, and a clinically meaningful survival benefit in the treatment of liver-dominated metastatic colorectal cancer (mCRC) according to data presented at #GEST2014.
“It is extremely safe and more than 50% of the patients had a benefit. We saw that less than 1% of patients had liver damage” said Dr. Kennedy. “We found that age didn’t matter. You could be any age. We had 90 year olds and they fared just as well.”
Dr. Kennedy and his colleagues conducted a multi-center retrospective study of 606 consecutive patients treated with SIR-Spheres at 11 sites between July 2002 and December 2011. Each enrolled patient had previously undergone a median of 2 prior lines of systemic chemotherapy (range: 0-6) for mCRC. The primary endpoints of the study were safety over 6 months from the procedure, all-cause mortality and overall survival (OS).
In this study, 77% of the patients were Caucasian and the mean age was 61.5 years (range: 20.8 -91.1 years) with 16% of the patients over the age of 75. Dr. Kennedy commented 93% of the patients received 90Y-RE as either 1 or 2 procedures, which were mainly targeted at the whole liver (65%) or right lobe (27%). In 97% of the cases, the hospital stay was less than 24 hours.
After a median follow-up of 8.6 months (range: 0.1-77.7 months), there were 503 deaths. For those patients receiving 90Y-RE as a second line therapy (N=206), the mean survival was 13.0 months. For those patients receiving it as third-line therapy (N= 184), the mean survival was 9.0 months, and the mean survival was 8.1 months for those receiving it as fourth-line therapy or greater (N = 158).
“Not too surprising we found that patients who had one or two rounds of chemotherapy had the best survival from the day they got the radiation. From that day forward, you did better if you had not exhausted all your chemo options” explained Dr. Kennedy. “Those patients who had already had maximum amount of chemotherapy going in still had a benefit, and the side effects were minimal.”
Dr. Kennedy presented the latest data at #GEST2014 stating all-cause cumulative mortality was 2.0% on day 30, 6.1% on day 60, and 14.0% on day 90 after the procedure and noting the safety profile as favorable. Dr. Kennedy said raised total bilirubin was 6.2% at baseline and increased to 22.6% by day 90 following the first treatment. The incidence of any adverse events did not differ based on prior lines of chemotherapy and only a minority of patients experienced grade 3 (4.9%) or grade 4 (2.7%) events at day 90 following the first treatment.
Dr. Kennedy also presented a talk entitled, “Pretreatment laboratory values predict survival following radioembolization of liver-dominant colorectal cancer metastases” which showed lower hemoglobin was a prognostic factor for shorter survival among these patients. He and his colleagues found that a review of pre-radioembolization laboratory parameters may improve median survivals if correctable values such as hemoglobin <10 g/dL are addressed prior to embolization with 90Y-RE.
“There is something that can be done to improve the results in the radiation. You have to make sure the hemoglobin is in the safe range. If they have a low hemoglobin level, they won’t respond as well as if they had a transfusion. So it is a small thing that could be done that would pay big dividends,” said Dr. Kennedy.
He said these findings are clinically relevant because there were 142,820 new cases of colorectal cancer in 2013 in the U.S. alone and there were 50,830 deaths. Liver metastases are the most common cause of morbidity and mortality in mCRC patients. Studies suggest that more than 75% of patients with mCRC are ineligible for resection.