Prospective non-randomized study of intraoperative assessment of surgical resection margin of colo-rectal liver metastases

Abstract

More than 50.0% of patients with colorectal cancer (CRC) develop liver metastases (CRLM) during the natural course of disesae. Surgical resection of the liver is the most potentially curative treatment. The goal of surgical treatment is to achieve a negative resection margin (RM-) of 1 mm, and thus provide the best prognosis for patients. The resection margin (RM) can be assessed by a pathologist (PA) on the resected liver specimen (RLS) and by surgeon intraoperatively (SA). The aim of this study was to determine the degree of agreement between SA and PA of RM and to compare their clinical significance. The study was double-blind, prospective, and nonrandomized. The surgeons assessed the RM for each RLS intraoperatively after resection. Liver resections were performed by four hepatobiliary surgeons. Their assessment of RM was compared with the assessment of RM performed by pathologists as the "gold standard". RM of 1 mm and more was rated as negative. Sensitivity, specificity, positive and negative predictive value were calculated, as well as the overall accuracy of the surgical assessment (SA) of RM in relation to the assessment of RM by the pathologist (PA). The influence of clinical outcome of SA and PA of RM were also analyzed. In the period from 1.1.2015 to 31.8.2019, 150 patients with resected CRLM were included in the study. A total of 337 RLS with 407 CRLMs were removed. There were 62 (18.4%) RLS with RM+ by SA. Pathologists agreed with surgeons in 48 (77.4%) cases, while in 14 (22.6%) cases they considered otherwise. Pathologists registered RM + in 83 (24.6%) cases. Surgeons agreed in 48 (57.8%) cases, while in 35 (42.2%) they considered otherwise. The sensitivity of the surgical assessment of RM + of 57.8%, specificity of 94.5%, positive predictive value of 77.4%, negative predictive value of 87.3%, and overall accuracy of 85.5% were obtained. Recurrence rate for RM+ patients was 42.9% (15/35, p=0.017) for SA and 32.7% (18/55, p=0.216) for PA. Three-year disease-free survival for RM-: RM+ was 64.5% and 36.1% (p = 0.01) by SA of RM, and 63.1%: 49.6% (p = 0.181) by PA of RM. Intraoperative assessment of RM is satisfactory, which is the goal of surgical treatment. However, there is a statistically significant difference in the assessment of RM + between surgeons and pathologists. In fact, RM + determined by the surgeon has a better prognostic effect on recurrence rate and DFS, compared to the assessment made by the pathologist.