Survival Advantage of Yttrium-90 Radioembolization to Systemic Therapy in Patients with Hepatic Metastases from Colorectal Cancer in the Salvage Setting: Results of a Matched Pair Study

Rationale and objectives: Patients with hepatic metastases from colorectal cancer have a poor prognosis in the salvage setting. This study assessed the survival benefit of adding transarterial ⁹⁰Y radioembolization in the salvage setting to systemic therapy.

Materials and methods: In this retrospective, matched-pair study, 21 patients who underwent radioembolization plus systemic therapy were matched with a cohort of 173 patients who received systemic chemotherapy alone in the salvage setting, defined as progression on at least two different regimens of systemic chemotherapy. Patients were matched one-to-one on Eastern Cooperative Oncology Group Performance Status, presence of extrahepatic disease, and presence of tumor KRAS mutation. Radioembolization patients underwent treatment using standard dosimetry to either a hepatic lobe or the whole liver. Survival data was analyzed using Kaplan-Meier analysis.

Results: Patients who underwent radioembolization plus systemic therapy vs. those who had systemic therapy alone had similar demographics and exposure to prior systemic chemotherapies. Median survival from the date of primary diagnosis was 38 (95% CI 26 to 50) v 25 (95% CI 15 to 35) months in radioembolization with systemic therapy vs. systemic therapy alone (p = 0.17). Median survival from the date of hepatic metastases was 31 (95% CI 23.8 to 38.2) v 20 months (95% CI 10.2 to 29.8) in radioembolization with systemic therapy vs. systemic therapy alone (p = 0.03).

Conclusion: The addition of radioembolization to systemic therapy in patients with metastatic colorectal cancer to the liver may improve survival in the salvage setting.