In an interim analysis of a phase III noninferiority trial (COLLISION) reported in The Lancet Oncology, van der Lei et al found that thermal ablation was noninferior to surgical resection in terms of overall survival in patients with small resectable colorectal liver metastases.
Study Details
In the trial, 296 eligible patients from sites in the Netherlands, Belgium, and Italy were randomly assigned between August 2017 and February 2024 to thermal ablation (n = 148) or surgical resection (n = 148) of all target colorectal liver metastases. Patients had to have ≤ 10 metastases of ≤ 3 cm and no extrahepatic metastases. The primary endpoint was overall survival; a hazard ratio (HR) of 1.30 was considered the upper limit of noninferiority.
Key Findings
Median follow-up at the prespecified interim analysis was 28.9 months (interquartile range = 0.3–77.8 months). The trial was stopped early for meeting predefined stopping rules. Noninferiority in overall survival was shown for thermal ablation vs resection (median overall survival not reached in either group; HR = 1.05, 95% confidence interval [CI] = 0.69–1.58, P = .83). Overall survival was 92.7% vs 92.9% at 1 year, 78.5% vs 79.6% at 2 years, and 51.2% vs 58.0% at 5 years. Noninferior local control was demonstrated for thermal ablation (median local control not reached in either group; HR = 0.13, 95% CI = 0.02–1.06, P = .057).
The thermal ablation group had a superior safety profile. Adverse events of any grade occurred in 19% vs 46% of patients (P < .0001). Grade 3 or 4 adverse events occurred in 7% vs 18% of patients. Serious adverse events were reported in 7% vs 20% of patients, including periprocedural hemorrhage requiring intervention (1% vs 5%) and infectious complications requiring intervention (4% vs 8%). There were no treatment-related deaths in the thermal ablation group and three in the resection group (from postoperative cardiac complications in two patients and sepsis and liver failure in one patient).
The investigators concluded: “The assumption that thermal ablation should be reserved for unresectable colorectal liver metastases requires re-evaluation and the preferred treatment should be individualised and based on clinical characteristics and available expertise.”
Martijn R. Meijerink, MD, of Cancer Centre Amsterdam, Amsterdam UMC, Amsterdam Vrije Universiteit, is the corresponding author of The Lancet Oncology article.
Disclosure: The study was funded by Medtronic-Covidien. For full disclosures of the study authors, visit thelancet.com.
