Ablation of colorectal liver metastasis: Interaction of ablation margins and RAS mutation profiling on local tumour progression-free survival
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To investigate effects of ablation margins on local tumour progression-free survival (LTPFS) according to RAS status in patients with colorectal liver metastases (CLM).
This two-institution retrospective study from 2005–2016 included 136 patients (91 male, median age 60 years) with 218 ablated CLM. LTPFS was performed using the Kaplan–Meier method and evaluated with the log-rank test. Uni/multivariate analyses were performed using Cox-regression models.
Three-year LTPFS rates for CLM with minimal ablation margin ≤10 mm were significantly worse than those with >10 mm in both mutant-RAS (29% vs. 48%, p=0.038) and wild-type RAS (70% vs. 94%, p=0.039) subgroups. Three-year LTPFS rates of mutant-RAS were significantly worse than wild-type RAS in both CLM subgroups with minimal ablation margin ≤10 mm (29% vs. 70%, p<0.001) and >10 mm (48% vs. 94%, p=0.006). Predictors of worse LTPFS were ablation margins ≤10 mm (HR: 2.17, 95% CI 1.2–4.1, p=0.007), CLM size ≥2 cm (1.80, 1.1–2.8, p=0.017) and mutant-RAS (2.85, 1.7–4.6, p<0.001).
Minimal ablation margin and RAS status interact as independent predictors of LTPFS following CLM ablation. While minimal ablation margins >10 mm should be always the procedural goal, this becomes especially critical for mutant-RAS CLM.
• RAS and ablation margins are predictors of local tumour progression-free survival.
• Ablation margin >10 mm, always desirable, is crucial for mutant RAS metastases.
• Interventional radiologists should be aware of RAS status to optimize LTPFS.
KeywordsColorectal neoplasms Metastasis DNA mutational analysis Interventional radiology Ablation techniques
Colorectal liver metastases
Local tumour progression
Local tumour progression-free survival
Rat sarcoma viral oncogene
This study has received funding by the National Institutes of Health/National Cancer Institute under award number P30CA016672
Compliance with ethical standards
The scientific guarantor of this publication is Bruno Odisio.
Conflict of interest
The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article.
Statistics and biometry
One of the authors has significant statistical expertise.
Written informed consent was obtained from all subjects (patients) in this study.
Institutional Review Board approval was obtained.
Study subjects or cohorts overlap
Some study subjects have been partially previously reported in one paper: Odisio BC, Yamashita S, Huang SY, et al (2017) Br J Surg 104:760–768
• multicentre study
- 6.Ruers T, Van Coevorden F, Punt CJA et al (2017) Local Treatment of Unresectable Colorectal Liver Metastases: Results of a Randomized Phase II Trial. JNCI J Natl Cancer Inst. https://doi.org/10.1093/jnci/djx015