Yttrium-90 (Y-90) resin microsphere embolization, when deployed as part of second-line therapy, contributed to 17.4 months median overall survival in patients with colorectal liver metastases, according to data from the RESiN registry. The results of the Radiation-Emitting Selective Internal Radiation-Spheres in Non-Resectable (RESiN) Registry are reported in one of the SIR 2022 Abstracts of the Year, “Survival Outcomes and Toxicities Following Y90 Radioembolization of Colorectal Cancer Metastatic to the Liver: 498 Patient Analysis from the RESiN Registry.”
“The RESiN registry was set up to study the real-world safety and efficacy outcomes following resin Y-90 microspheres in patients with unresectable liver cancer. Patients with colorectal cancer make up a large component of this demographic,” said Erica Emmons, MD, one of the abstract authors and one of the recipients of the SIR Foundation Radiology Resident Research Award. “However, the best use for Y-90 in this setting is not well defined. Although chemotherapeutic and immunologic therapies have advanced greatly, we set out to better define the role for Y-90 in hepatic metastases of colorectal cancer.
“The Vanderbilt-Ingram Cancer Center acted as our primary site and coordinating center for the RESiN registry which tracks overall survival, time to progression and toxicity levels in patients who receive Y-90 therapy for their unresectable liver cancer,” she added.
According to Dr. Emmons, colorectal cancer is the fourth-most-common malignancy, and the liver is the most common site of metastasis—and so there is a large population of patients who have hepatic disease. “For patients with unresectable disease, survival drops considerably when second-line therapy is needed, and the outlook is bleaker for patients who fail second-line treatment,” Dr. Emmons said. “We looked to measure outcomes by breaking up the patient group by the number of lines of chemotherapy received prior to radioembolization.”
The demographic reported for this abstract comprised of 498 patients treated between 2015–2020. 47% of patients had a tumor burden of less than 10%, while 26% had a burden of 11–25% and 28% had a burden greater than 26%. Of the total patient population, 17% received Y-90 as part of their first-line therapy, while 41% received it in the second line and 43% received it during the third line or beyond.
“Our cohort not only had a high disease burden, but also was heavily pre-treated, with many people enrolling as salvage therapy,” said Dr. Emmons. “However, overall survival in the second-line therapy cohort was 17.4 months, which compares favorably to other data using arterial therapy for colorectal carcinoma. Additionally, salvage survival was 12.5 months, which exceeds the length of survival with a number of systemic agents that are used in the same setting. These outcomes were achieved with a significant toxicity rate of less than 10%.”
According to Dr. Emmons, there are several more subgroup analyses in progress and, given the survival findings, the researchers hope to see prospective trials developed to confirm the value of Y-90 in this patient population. “We hope that Y-90 will be more completely incorporated into the National Comprehensive Cancer Network Guidelines.”
