Radioembolization and systemic chemotherapy improves response and survival for unresectable colorectal liver metastases

To evaluate the role of radioembolization and systemic chemotherapy as a combined modality therapy for unresectable colorectal liver metastases. Prospective database of a major yttrium-90 microsphere radioembolization treatment center in Sydney, Australia, that included 140 patients with unresectable colorectal liver metastases was analyzed. Tumor response, overall survival, treatment-related complications and an evaluation of its role as a combined modality therapy with systemic chemotherapy were performed. One hundred and thirty-three patients (95%) had a single treatment, and seven patients (5%) had repeated treatments. Response following treatment was complete in two patients (1%), partial in 43 patients (31%), stable in 44 patients (31%), and 51 patients (37%) developed progressive disease. Combining chemotherapy with radioembolization was associated with a favorable treatment response (P = 0.007). The median overall survival was 9 (95% CI 6.4-11.3) months with a 1-, 2-, and 3-year survival rate of 42, 22, and 20%, respectively. Primary tumor site (P = 0.019), presence of extrahepatic disease (P = 0.033), and a favorable treatment response (P < 0.001) were identified as independent predictors for survival. Combined modality therapy appears to improve tumor response rates. Survival is influenced by tumor site, presence of extrahepatic disease, and response to therapy. Yttrium-90 microsphere radioembolization is safe and may best be combined with systemic chemotherapy for patients with unresectable colorectal liver metastases.