Yttrium-90 radioembolization as salvage therapy for colorectal cancer with liver metastases

Few patients with metastatic colorectal cancer (mCRC) are candidates for resection of their hepatic disease. Yttrium-90 (⁹⁰Y) radioembolization has promise in the treatment of unresectable mCRC. We conducted a retrospective study to assess the efficacy in patients with refractory mCRC who underwent ⁹⁰Y radioembolization. Patients with unresectable mCRC with liver metastases treated at The Ohio State University were included in this analysis. Demographic data, carcinoembryonic antigen (CEA) values, observed toxicities, and information on prior therapies were collected. Response was assessed by RECIST (Response Evaluation Criteria in Solid Tumors) 1.1 criteria. Overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method. Twenty-four patients (median age, 63 years) were included. Of the patients, 54% had extrahepatic disease; 67% had bilobar involvement. The patients had received a median of 3 prior therapies. No objective responses were observed. Five patients had a CEA response. Median PFS and OS were 3.9 months (95% CI, 2.4-4.8 months) and 8.9 months (95% CI, 4.2-16.7 months), respectively. Patients older than 65 years had improved PFS (4.6 vs. 2.4 months) and OS (14 vs. 5.5 months) vs. younger patients, likely due to receipt of ⁹⁰Y treatment earlier in their disease course. The presence of extrahepatic disease and the absence of CEA response appeared negatively predictive of efficacy. Toxicities were expected and manageable. ⁹⁰Y radioembolization is active in select patients with refractory mCRC and with liver metastases, and is safe and well tolerated in the elderly. In patients with extensive extrahepatic disease, ⁹⁰Y should be used in combination with chemotherapy. CEA may be a predictor of efficacy.