Laparoscopic and percutaneous microwave ablation to treat liver metastasis from colon cancer. A tool for long-term iterative strategy: results from a high volume center

Abstract

Introduction: Colorectal cancer is the third most common tumor worldwide. The liver is involved in 20-30% of cases, which strongly affects the long-term outcome. Liver resection and systemic chemotherapy are the current standard of care for colorectal liver metastasis (CRLMs), but microwave thermal ablation (MWA) is emerging as a viable option in non resectable patients or to achieve treatment with parenchymal spearing approach. Purpose: Verify safety and efficacy of MWA to treat CRLMs. Methods: Retrospective analysis of a prospective database of patient with CRLMs below maximum diameter of 3cm, treated with laparoscopic or percutaneous MWA from 2009 to 2019. Patients were not suitable for liver resection (tumor in critical position near major hepatic structures, insufficient future liver remnant after resection, comorbidity). Efficacy of the MWA was evaluated according to mRECIST criteria. Statistical analysis was performed to identify safety profile, overall survival and recurrence rate. Results: A total of 79 nodules were treated with 55 ablation procedures in 51 patients. Thirty-one nodules were treated by percutaneous approach; 48 nodules by laparoscopy approach. A single nodule was treated in 69% of procedures. The median tumour size was 18 mm (range, 8-30 mm). At 6 months complete response (100% of necrosis) was obtained in 85% of nodules treated, partial response in 11.3% and a progression disease in 3.7%. With a median follow up of 18 months (9,9-26), the overall recurrence rate in all organs was 64.7% (33 patients), with a local tumour progression (LTP) of 27.4% (14 patients), an intrasegmental recurrence (ISR) of 25.4% (13 patients), a intrahepatic recurrence (IHR) of 17.6% (9 patients), an extrahepatic recurrence (EHR) of 5.8% (3 patients) with a disease free rate of 35.2% (18 patients). Perioperative mortality was 0%. Overall morbidity was 18%, with Dindo-Clavien complications ≥3 in 2%. The median length of stay was 1 day. Overall 1-, 3-, and 5-year survival rates were 92.5%, 55.9% and 43.2%. Conclusion: In this mono-centric study MWA appears safe and effective to treat CRLMs when resection is not feasible or a major hepatectomy in fragile patients is necessary. Considering the low morbidity and repeatability of this procedure, it can be a viable option to treat patients with recurrent disease in the era of effective chemotherapy and multimodal treatments.