Prospective Non-Randomized Study of Intraoperative Assessment of Surgical Resection Margin of Colo-Rectal Liver Metastases

Abstract

Introduction: More than 50% of patients with colorectal cancer (CRC) develop liver metastases during the natural course of disease. Surgical resection is currently the most potentially curative method in the treatment of colorectal liver metastases (CRLM). The goal of surgery is to achieve a negative resection margin (RM) of at least 1 mm, which provides the best prognosis for patients. The RM can be assessed by the pathologist of the resected liver specimen (RLS) and by the surgeon intraoperatively. The aim of this research paper is to determine the degree of agreement on intraoperative assessment of the RM by the surgeon and histopathological RM assessment by the pathologist. Material and methods: This prospective non-randomized double-blind study was approved by the Ethics Committee of the Oncology Institute of Vojvodina and registered on ClinicalTrials.gov #NCT04634526. The study was conducted at the Oncology Institute of Vojvodina, Sremska Kamenica, Serbia. An experienced hepatobiliary surgeon assessed RM for every specimen intra-operatively, immediately after CRLM resection. Resected CRLM lesions were analyzed by two experienced pathologists. These data were compared with pathological RM assessment as a "gold standard". RM of 1 mm or more was rated as negative RM (RM-). Disease-free survival (DFS) and recurrence rate was calculated by RM status defined by surgeon and by pathologist. Results: From 01 January 2015 to 31 August 2019, 98 patients were enrolled in the study. There were 219 RLS with 245 CRLM. The surgeon registered positive RM (RM+) of <1mm in 41 (18.7%) RLS. Taking the result of the histopathological assessment (HPA) as the "gold standard", it was determined that RM was true positive in 32 (14.6%) cases. False positive RM was found in 9 (4.1%) cases. False negative RM was found in 20 (9.1%) cases. True negative RM was found in 158 (72.2%) cases. Sensitivity of surgical assessment (SA) of RM+ was 61.5% (32/52). Specificity of SA of RM+ was 94.6% (158/167). The positive predictive value (PPV) was 78.0% (32/41), while the negative predictive value (NPV) was 88.8% (158/178). The overall accuracy of the RM+ SA was 86.8% (190/219). There was no statistically significant difference in the assessment of RM+ per RLS by surgeon and pathologists (p=0.061), but it was significant when analyses per patients was performed (p=0.017). Recurrence rate for RM+ patients was 48.1% (13/27, p=0.05) for SA and 35.0% (14/40, p=0.17) for HPA. Three year DFS for RM-and RM+ was 66.5% and 27.9% (p=0.04), respectively, by SA, and 64.8% and 42.1% (p=0.106), respectively, by HPA.

Impact of microscopic incomplete resection for colorectal liver metastases on surgical margin recurrence: R1‐Contact vs R1 < 1 mm margin width

“…Some authors have recently suggested that intraoperative assessment of resection margins could be clinically meaningful, and that margin re-resection could be indicated in selected cases. 28,29 Although in our series R1-contact was associated with poorer outcomes compared to R1 < 1 mm, it is difficult to draw any conclusion on whether intraoperative or postoperative margin reresection could improve the outcome. In fact, only two patients recurred with isolated surgical bed recurrence, and they belonged to the R1-contact group.…”

Tumor attachment to Major intrahepatic vascular for Colorectal liver metastases

“…It was believed that increasingly efficient chemotherapy may have changed the long-term outcome after a R1 resection, especially in patients with advanced metastatic disease [ 6 , 16 ]. A series of studies have testified and showed benefit of modern chemotherapy on R1 resection that there were no negative impacts in survival rates, particularly in patients with optimal morphological or major histopathological responses [ 17 ].…”

Intraoperative assessment of the curative potential to predict survival after gastric cancer resection: A national cohort study

“…Nevertheless, intraoperative decision-making by the individual surgeon will still have impact on the probability to perform a curative resection. Protic et al 18 assessed patients undergoing surgery for colorectal liver metastasis and intraoperative assessment of resection margins by an experienced hepatobiliary surgeon improved the prognostic impact on recurrence rate and disease-free survival compared to standard postoperative histopathological assessment by a pathologist. In the present study, patients with pathological Stages 0-2 had better overall survival than patients where the operating surgeon had deemed the operation curative.…”