Propensity matched analysis of the use of resection and ablation in the treatment of colorectal liver metastases

ABSTRACT NUMBER: NESTAC_09

 

AUTHORS
Sai SJ Wunnava, Stuart M Robinson, Steven A White, Derek M Manas, Peter Littler

CORRESPONDING AUTHOR CONTACT EMAIL
ku.ca.eltsacwen@avannuw.j.s.s

MAIN ABSTRACT TEXT

Introduction
Hepatic resection remains the gold-standard in management of colorectal liver metastases however thermal ablation is often utilised as an alternative in patients with small volume oligometastatic disease or significant comorbidity. While studies have compared resection and ablation in HCC, level one evidence is lacking in CRLM patients.

Methods
Single centre retrospective review of 562 cases (2000-2018).

Proprensity matching, using IBM SPSS Statistics v24, was employed to minimise inter-cohort variance in patient characteristics. Patients were matched for tumour-specific factors including number, diameter and synchronousness further to patient comorbidity.

Kaplan-Meier estimator was used to estimate survival with differences between groups analysed using log-rank test. Factors significant on log-rank analysis were analysed using Cox proportional hazard model. P<0.05 was considered significant.

Results
Of 562 patients treated, 509 underwent resection (90.6%) and 53 underwent ablation (9.43%). Median follow-up was 32 months in the resection cohort and 14 months in the ablation cohort. Unmatched univariate analysis showed poorer overall survival (37 vs. 17 months; p=0.031) but not progression free survival (12 vs. 5.5 months; p=0.219).

Propensity matching compared 38 resection and 38 ablation patients. Repeating log-rank analysis showed no difference in overall survival (42 vs. 41 months p=0.195) or progression free survival (13 vs. 14 months; p-0.887). Factors significant on Cox regression analysis in the resection cohort included age, chemotherapy prior to procedure, CEA>200, complete resection margin, vascular invasion and presence of primary in situ.

Conclusion
In appropriately selected patients, ablation offers a viable alternative to resection in the management of CRLM.