How Can We Improve the Survival of Patients with Colorectal Liver Metastases Using Thermal Ablation?

Simple Summary: We can improve the long-term survival of patients with colorectal liver metastases (CRLMs) using thermal ablation. Thermal ablation can provide equivalent long-term survival compared with liver resection for patients with small (≤3 cm) and few CRLMs. We strongly recommend applying thermal ablation for such patients whose liver resection is high risk. Thermal ablation can be combined with liver resection to expand the resectability of numerous bilateral CRLMs. Furthermore, thermal ablation might result in better survival than liver resection in patients receiving effective neoadjuvant chemotherapy. Thermal ablation should be added to systemic chemotherapy for unresectable CRLMs. Microwave ablation therapy, especially microwave thermosphere ablation, can provide better local control and increased disease-free survival than radiofrequency ablation. Furthermore, randomized controlled trials or propensity score matching studies using a prospective database are needed to confirm thermal ablation's effectiveness and identify the target population that will benefit most from thermal ablation. Thermal ablation has been widely used for patients with small colorectal liver metastases (CRLMs), even for resectable cases; however, solid evidence has been scarce. (1) Thermal ablation versus liver resection. Some propensity-score matching studies using patients with balanced baseline characteristics have confirmed less invasiveness and the comparable survival benefits of thermal ablation to liver resection. A more recent pivotal randomized controlled trial comparing thermal ablation and liver resection was presented during the American Society of Clinical Oncology 2024 meeting. Diameter ≤ 3 cm, ten or fewer resectable and ablatable CRLMs were assigned to thermal ablation or liver resection. No differences were observed in the overall survival and local and distant progression-free survival with less morbidity. (2) Combination of thermal ablation and liver resection. Four matching studies demonstrated comparable data between the combination and liver resection alone groups in the long-term survival and recurrence rates without increasing the postoperative complication rates. The selection of the two approaches depends primarily on the number, size, and location of the CRLMs. (3) Chemotherapy in combination with thermal ablation. A propensity-score matching study comparing thermal ablation ± neoadjuvant chemotherapy was conducted. The addition of neoadjuvant chemotherapy was an independent predictive factor for good progression-free survival without increasing morbidity. Two randomized controlled trials demonstrated that additional thermal ablation to systemic chemotherapy can improve the overall survival for initially unresectable CRLMs. (4) Conclusions. Thermal ablation can provide survival benefits for patients with CRLMs in various situations, keeping adequate indications. [ABSTRACT FROM AUTHOR]