Outcomes of Therasphere Radioembolization for Colorectal Metastases

The liver is the most common site for colorectal cancer (CRC) metastases. Radioembolization with yttrium-90 (Y90) represents an alternative approach in the management of unresectable hepatic colorectal metastases. The objective of this study was to evaluate outcomes after treatment with Y90.

A retrospective review of patients undergoing Y90 glass microsphere treatment for metastatic CRC from 2009 to 2013 was conducted. Multivariable analysis (MVA) of factors related to overall survival (OS) was performed using the Cox proportional hazard and OS estimates were calculated using the Kaplan-Meier method.

We identified 68 patients. Median and 2-year OS were 11.6 months and 34%. For patients with ≤ 25% hepatic burden of disease (HBD) and 1 chemotherapy regimen, 2-year OS was 63%. Median and 2-year OS for patients with ≤ 25% versus > 25% HBD were 19.6 months and 42% versus 3.4 months and 0% (P < .0001). Univariate analysis revealed that higher HBD, ≥ 3 lines of chemotherapy received, and higher carcinoembryonic antigen (CEA) were found to be significant predictors of worse OS. MVA revealed age, > 25% HBD, ≥ 3 lines of chemotherapy, and higher CEA were independently prognostic for increased mortality, and resected status of the primary tumor was associated with decreased mortality. The presence of extrahepatic metastases was not prognostic. Toxicities were mild and only 5 patients experienced Grade 3/4 biochemical toxicity.

Yttrium-90 was associated with acceptable OS with minimal morbidity in this series. Minimal exposure to chemotherapy and low HBD were found to be associated with better OS, however, even patients with chemotherapy-refractory disease received a benefit from treatment.