Surgical microwave ablation of otherwise non-resectable colorectal cancer liver metastases: Expanding opportunities for long term survival

Background: Colorectal liver metastases (CRLM) are the most common extra-lymphatic metastases in colorectal cancers, however, only 15–20% of these patients are candidates for resection. We reviewed our institutional experience with 135 surgical ablations for unresectable CRLM. Methods: Retrospective review of surgically ablated CRLM from 2009 to 2018. Patient-specific variables were obtained from the medical record. Kaplan-Meier modeling was performed for survival analyses. Results: We ablated 135 CRLM in 36 patients over 40 procedures. Median age was 52 years and 58% of patients were male. All patients received systemic chemotherapy. The ablation procedure was completed laparoscopically in 68% of procedures. Median number of ablated lesions per patient was 2 (range 1–15). Median maximum diameter of ablated lesions was 1.9 cm (range 0.5–12.2). Median follow up of the study was 28 months. In this time, median disease-free survival was not reached. Of the 135 lesions ablated, the per-lesion recurrence rate was 6/135 (4.4%). Median overall survival was 81 months. Conclusions: Surgical ablation of CRLM can provide excellent local control and long-term survival outcomes in patients who may otherwise not be candidates for other liver-directed therapies.