Abstract No. 560 Survival and Toxicity Comparison of Metastatic Colorectal Cancer (mCRC) Patients with and without Prior Hepatectomy from the RESiN Registry

Multi-institutional analysis comparing the efficacy and safety utilizing radioembolization (Y-90 resin) of hepatic metastatic mCRC in patients with and without prior hepatectomy. A retrospective analysis was performed of 493 patients with mCRC enrolled in a prospective, multicenter observational registry. Patients were predominately white (66.9%) and male (51.1%). Most patients (51.5%) had a ECOG of 0, median baseline albumin of 4, and a median bilirubin of 0.6-0.7. Seventy (14.2%) underwent hepatic surgery for tumor removal prior to TARE therapy, and 423 (85.8%) received TARE therapy without prior surgery. Of the patients who underwent surgery, 20% had three or more segments removed, 27% had a lobectomy, and 53% other (a combination or indeterminate report). Kaplan-Meier analysis was performed to determine median OS in each study arm. Additional analysis was performed regarding grade three or higher liver toxicities as determined by the Common Terminology Criteria for Adverse Events (v.5). No difference in ECOG, sex, or median age in those that had surgery and those that did not. Out of the measured parameters of hepatic toxicity, bilirubin was affected the most in the treatment group with 12-22% demonstrating grade three or above toxicity. This was not statistically significant. There was no difference in the number of lines of chemotherapy between patients that had surgery and those that did not (p< 0.001). There was no statistically significant difference in median OS between those who had surgery (18.1 months, 95% CI=12.6-24.9) and those who did not (14.6 months, 95% CI=12.7-16.7) (p=0.1). With no significant difference in OS, and grade three or above toxic events between the two study arms, this real-world data indicates that Y-90 would serve as a viable primary treatment option in the setting of liver dominant mCRC when compared to surgical options. Substantial benefits would include potential decreased healthcare costs, decreased length of hospital stays, and decreased physiologic insult to the body. Findings suggest TARE is a critical treatment regimen from a multidisciplinary treatment approach and further substantiates interventional oncology in quality patient care.