The impact of Kirsten rat sarcoma ( KRAS ) status on local tumor progression after surgical ablation of colorectal liver metastases

Kirsten rat sarcoma mutation was reported to adversely affect local tumor control after percutaneous ablation of colorectal liver metastasis. Nevertheless, the effect of Kirsten rat sarcoma mutation on surgical ablation has not been investigated in the literature. The aim of this study is to analyze the impact of Kirsten rat sarcoma mutation on local recurrence after surgical ablation of colorectal liver metastasis. This was an institutional review board–approved study of patients who underwent surgical ablation of colorectal liver metastasis between 2005 and 2023 at a single center and underwent Kirsten rat sarcoma testing with ≥1 year follow-up. Local recurrence was analyzed using univariate Kaplan–Meier and multivariate Cox hazard models. A total of 163 patients with 424 lesions fulfilled inclusion criteria. Fifty (30.7%) patients received radiofrequency ablation and 113 (69.3%) patients received microwave ablation. Fifty-seven patients (32.2%) with 177 lesions were found to have a Kirsten rat sarcoma mutation. Patients with Kirsten rat sarcoma mutation had a larger number of tumors, percentage of posteriorly located tumors, and tumor burden score compared with those with wild-type Kirsten rat sarcoma. Nevertheless, there was no difference between the groups regarding local recurrence per lesion (15% vs 17%, respectively, P  = not significant). Independent predictors of local recurrence included tumor size, ablation margin, and blood vessel proximity for radiofrequency ablation compared with tumor size and ablation margin for microwave ablation. There was no effect of Kirsten rat sarcoma mutations on local recurrence after surgical radiofrequency ablation or microwave ablation of colorectal liver metastasis in this study. Tumor size and ablation margin remained as independent predictors.