Thermal Ablation in the Management of Colorectal Cancer Patients with Oligometastatic Liver Disease.

BACKGROUND: Surgical resection of limited colorectal liver disease improves long-term survival and can be curative in a subset of selected cases. Image-guided percutaneous ablation therapies have emerged as safe and effective alternative options for selected patients with unresectable colorectal liver metastases (CLM) that can be ablated with margins. Ablation causes focal destruction of tissue and has increasingly been shown to provide durable eradication of tumors.

METHODS: A selective review of literature was conducted in PubMed, focusing on recent studies reporting on the safety, efficacy, and long-term outcomes of percutaneous ablation modalities in the treatment of CLM. The present work gives an overview of the different ablation techniques, their current clinical indications, and reported outcomes from most recently published studies. The 'test of time' concept for using ablation as a first local therapy is also described.

RESULTS: There are several thermal ablative tools currently available, including radiofrequency ablation (RFA), microwave ablation, and cryoablation. Most data to date originated from the application of RFA. Adjuvant thermal ablation in the treatment of oligometastatic colon cancer liver disease offers improved oncologic outcomes. The ideal CLM amenable to percutaneous ablation is a solitary tumor with the largest diameter up to 3 cm that can be completely ablated with a sufficient margin. 5-year overall survival rates up to 70% after ablation of unresectable CLM have been reported. Pathologic confirmation of complete tumor necrosis with margins over 5 mm provides best long-term local tumor control by thermal ablation.

CONCLUSION: Current evidence suggests that percutaneous ablation as adjuvant to chemotherapy improves oncologic outcomes of patients with CLM. For small tumors that can be ablated completely with clear margins, percutaneous ablation may offer outcomes similar to those of surgery.