The role of radiofrequency ablation for treatment of metachronous isolated hepatic metastasis from colorectal cancer

We investigated recurrence pattern and oncologic outcomes after treatment of metachronous isolated liver metastases from colorectal cancer according to treatment modality. We retrospectively analyzed 123 patients treated with hepatic resection and 82 patients treated with radiofrequency ablation (RFA) for metachronous isolated hepatic metastasis from colorectal cancer (HMCRC). We compared clinicopathological data, recurrence pattern, and recurrence-free survival (RFS) rates after the treatment of hepatic metastasis between patients treated with RFA and resection. The patients in the 2 groups were similar in gender, location of primary tumor, disease-free interval to hepatic metastasis, pathologic stage of primary tumor, and number of hepatic metastasis. The age was older in RFA group but it was not statistically different. The mean diameter of the largest hepatic mass was greater in the resection group than in the RFA group (3.1 vs 1.9 cm, P < 0.001). Chemotherapy after the treatment of hepatic metastasis was more commonly given in hepatic resection group (76.4% vs 62.2%, P = 0.04). Recurrence after the treatment of hepatic metastasis was not significantly different between the 2 groups (54.5% vs 65.9% in the resection and RFA groups). However, intrahepatic recurrence without extra-hepatic metastases was more common in the RFA group than in the resection group (47.5% vs 12.1%, P < 0.001). The RFS rate after the treatment of hepatic metastasis was significantly higher in resection group (48.6% vs 33.7%, P = 0.015). The size and number of hepatic metastasis, primary tumor stage, disease-free interval to hepatic metastasis, and the modality of treatment (RFA vs resection) for hepatic metastasis were confirmed as associated factors with re-recurrence after the treatment of hepatic metastasis. Among patients with solitary hepatic metastases of ≤3 cm, marginal recurrence was higher in the RFA group (3% vs 17.2%) and re-RFA was performed to achieve comparable recurrence rate (3% vs 5.2%, P = 0.662), the RFS rate was not different between the resection and RFA group (52.4% vs 53.4%, P = 0.491). Surgical resection for HMCRC showed higher RFS. However, the RFS rate in patients with a solitary hepatic metastasis of ≤3 cm was similar between the resection and RFA groups.