Early Results of Liver Resection and Role of Extended Histology (LIREcH) Study

Abstract

Introduction: Positive margin of the resected colorectal liver metastases (CRLM) is an independent negative prognostic factor. However, liver resection involves an unaccounted 5-6mm tissue loss due to the use of energy devices or CUSA. The aim of this study is to assess the correlation between the margin status on the specimen side(R1s) and that from the patient side (base of resection)(R1p) and its influence on the outcomes. Methods: In this prospective study, patients over 18 years undergoing resection of CRLM (< 5cm), with suspected close resection margins were included. Sample from resection base was collected using CUSA for the evaluation of R1p. Primary outcome was the correlation of R1s and R1p. Secondary endpoints were the rates of local recurrence, liver specific recurrence, overall morbidity, and post-operative hospital stay. Results: 45 specimens and the corresponding CUSA samples from the base from 26 patients were analysed. 82% patients received neo-adjuvant chemotherapy. RAS mutation was positive in 14% of patients. Among the 45 specimens, 28(62%) had margin clearance of < 1mm, 1-4mm in 15%, 5-6mm in 13%, >9mm in 20%. However, only 5/28(17%) had tumour cells on the patient side (R1p). Overall, one patient had liver specific recurrence at 8 months. None of the others had local recurrence. Median post-operative hospital stay was 6.4 days. Conclusion: Early results of this on-going study suggest poor correlation between R1s and R1p. Confirmation of the results from larger cohort might help in patient counselling, surveillance, and in pre-operative planning of the resection of bilobar metastases.