Ablation therapy for patients with colorectal liver metastases with and without extrahepatic metastases: evaluation of long-term outcomes and prognostic factors

Purpose Ablation is a valuable treatment alternative to surgery for colorectal liver metastases. This study reports the long-term clinical outcomes in patients treated with ablation for colorectal liver metastases with or without extrahepatic metastases. Methods Patients with colorectal liver metastases treated with ultrasound-guided ablation at Herlev Hospital, Denmark were included in this retrospective study. Results This study included 284 patients with 582 metastases. Complete ablation was obtained in 258 patients (91%) evaluated within 6 weeks. During follow-up, 94 patients (33%) developed local recurrence. The median survival for all patients was 31 months, with 1-, 3-, and 5-year survival rates of 82%, 45%, and 21%, respectively. The median survival for patients with extrahepatic metastases (n=49, 17%) was 24 months compared with 33 months for patients without (P=0.142). Propensity score-adjusted Cox regression showed that extrahepatic metastases were associated with increased mortality, with a hazard ratio (HR) of 1.45 (95% confidence interval [CI], 1.02 to 2.05; P=0.039). In multivariate Cox regression analysis for all patients, increased mortality risk was found for a diameter ≥2.6 cm (HR, 1.59; 95% CI, 1.23 to 2.05), >1 metastasis (HR, 1.66; 95% CI, 1.28 to 2.16), and extrahepatic metastases (HR, 1.45; 95% CI, 1.04 to 2.03). Male sex (HR, 0.75; 95% CI, 0.58 to 0.98) and receiving chemotherapy (HR, 0.69; 95% CI, 0.52 to 0.92) were associated with decreased mortality. Conclusion Ablation for colorectal liver metastases offers acceptable survival rates, including for patients with extrahepatic metastases. In addition, chemotherapy was associated with improved survival for both patients with and without extrahepatic metastases.