Critical appraisal of surgical margins according to KRAS status in liver resection for colorectal liver metastases: Should surgical strategy be influenced by tumor biology?

BACKGROUND

KRAS mutation is a negative prognostic factor for colorectal liver metastases. Several studies have investigated the resection margins according to KRAS status, with conflicting results. The aim of the study was to assess the oncologic outcomes of R0 and R1 resections for colorectal liver metastases according to KRAS status.

METHODS

All patients who underwent resection for colorectal liver metastases between 2010 and 2015 with available KRAS status were enrolled in this multicentric international cohort study. Logistic regression models were used to investigate the outcomes of R0 and R1 colorectal liver metastases resections according to KRAS status: wild type versus mutated. The primary outcomes were overall survival and disease-free survival.

RESULTS

The analysis included 593 patients. KRAS mutation was associated with shorter overall survival (40 vs 60 months; P = .0012) and disease-free survival (15 vs 21 months; P = .003). In KRAS-mutated tumors, the resection margin did not influence oncologic outcomes. In multivariable analysis, the only predictor of disease-free survival and overall survival was primary tumor location (P = .03 and P = .03, respectively). In KRAS wild-type tumors, R0 resection was associated with prolonged overall survival (74 vs 45 months, P < .001) and disease-free survival (30 vs 17 months, P < .001). The multivariable model confirmed that R0 resection margin was associated with prolonged overall survival (hazard ratio = 1.43, 95% confidence interval: 1.01-2.03) and disease-free survival (hazard ratio = 1.42; 95% confidence interval: 1.06-1.91).

CONCLUSIONS

KRAS-mutated colorectal liver metastases showed more aggressive tumor biology with inferior overall survival and disease-free survival after liver resection. Although R0 resection was not associated with improved oncologic outcomes in the KRAS-mutated tumors group, it seems to be of paramount importance for achieving prolonged long-term survival in KRAS wild-type tumors.

Relevance of early CT scan diagnosis of blunt diaphragmatic injury: A retrospective analysis from the Northern French Alps Emergency Network

INTRODUCTION

Diaphragmatic rupture following blunt trauma occurs rarely. Classically described after high-velocity accidents, ruptures are often associated with multiple organ injuries. The diagnosis is sometimes difficult. The goal of this study was to analyze and to discuss the modalities of early radiologic diagnosis and management of these injuries.

PATIENTS AND METHODS

This multicenter retrospective study included patients seen between 2009 and 2017 within the Northern Alpine Emergency Network [REseau Nord Alpin des Urgences (RENAU)]. Clinical, radiologic and surgical data from all patients sustaining blunt diaphragmatic rupture were studied.

RESULTS

Thirty-one patients (18 men and 13 women), median age 44, were included. The principle mechanism of injury was road or traffic accidents for 22 patients. Diaphragmatic rupture occurred on the left side in 23 patients. Diagnosis was delayed in two patients, at 11 days and three months after the initial accident. Chest X-rays were diagnostic in 18 of 29 patients. CT scan was the reference investigation since it was performed in all patients and confirmed the diagnosis in 26 instances. Repair was surgical via a midline laparotomy in 27 patients, via laparoscopy in three, and via thoracoscopy in one. Three patients died.

CONCLUSION

At urgent surgical exploration in the unstable blunt trauma patient, the surgeon should keep in mind the relatively poor diagnostic performance of chest X-rays. Accurate diagnosis relies on routine inspection of the diaphragmatic cupolas. In the stable trauma victim, contrast-enhanced abdomino-thoracic CT with reconstruction can lead to early diagnosis, which allows for repair under optimal conditions, whether by laparotomy, laparoscopy or thoracoscopy, according to local conditions and expertise.