Prognostic benefit of preoperative transarterial chemoembolization in upfront resectable large hepatocellular carcinoma: a multicentric propensity score based analysis of European high-volume centers.

BACKGROUND: Hepatocellular carcinoma (HCC) have a dismal prognosis and any effective neoadjuvant treatment has been validated to date. We aimed to investigate the role of neoadjuvant transarterial chemoembolization (TACE) in upfront resectable HCC larger than 5 cm. METHODS: This is a multicentric retrospective study comparing outcomes of large HCC undergoing TACE followed by surgery or liver resection alone before and after propensity-score matching (PSM). RESULTS: A total of 384 patients were included of whom 60 (15.6%) received TACE. This group did not differ from upfront resected cases neither in terms of disease-free survival (p = 0.246) nor in overall survival (p = 0.276). After PSM, TACE still did not influence long-term outcomes (p = 0.935 and p = 0.172, for DFS and OS respectively). In subgroup analysis, TACE improved OS only in HCC ≥10 cm (p = 0.045), with a borderline significance after portal vein embolization/ligation (p = 0.087) and in single HCC (p = 0.052). CONCLUSIONS: TACE should not be systematically performed in all resectable large HCC. Selected cases could however potentially benefit from this procedure, as patients with huge and single tumors or those necessitating of a PVE.

ERS: A simple scoring system to predict early recurrence after surgical resection for hepatocellular carcinoma.

BACKGROUND: Surgical resection (SR) is a potentially curative treatment of hepatocellular carcinoma (HCC) hampered by high rates of recurrence. New drugs are tested in the adjuvant setting, but standardised risk stratification tools of HCC recurrence are lacking. OBJECTIVES: To develop and validate a simple scoring system to predict 2-year recurrence after SR for HCC. METHODS: 2359 treatment-naïve patients who underwent SR for HCC in 17 centres in Europe and Asia between 2004 and 2017 were divided into a development (DS; n = 1558) and validation set (VS; n = 801) by random sampling of participating centres. The Early Recurrence Score (ERS) was generated using variables associated with 2-year recurrence in the DS and validated in the VS. RESULTS: Variables associated with 2-year recurrence in the DS were (with associated points) alpha-fetoprotein (<10 ng/mL:0; 10-100: 2; >100: 3), size of largest nodule (≥40 mm: 1), multifocality (yes: 2), satellite nodules (yes: 2), vascular invasion (yes: 1) and surgical margin (positive R1: 2). The sum of points provided a score ranging from 0 to 11, allowing stratification into four levels of 2-year recurrence risk (Wolbers' C-indices 66.8% DS and 68.4% VS), with excellent calibration according to risk categories. Wolber's and Harrell's C-indices apparent values were systematically higher for ERS when compared to Early Recurrence After Surgery for Liver tumour post-operative model to predict time to early recurrence or recurrence-free survival. CONCLUSIONS: ERS is a user-friendly staging system identifying four levels of early recurrence risk after SR and a robust tool to design personalised surveillance strategies and adjuvant therapy trials.

High amylase concentration in drainage liquid can early predict proximal and distal intestinal anastomotic leakages: A prospective observational study.

Background: Anastomotic leak (AL) is a serious complication in digestive surgery. Early diagnosis might allow clinicians to anticipate appropriate management. The aim of this study was to assess the predictive value of amylase concentration in drain fluid for the early diagnosis of digestive tract AL. Materials and Methods: Hundred and fourteen consecutive patients "at risk" of AL, in whom a flexible drainage was placed by surgeon's choice after digestive anastomosis were included. Patients with eso-gastric, bilio-digestive, and pancreatic anastomoses were excluded. Drain amylase measurement (DAM) was routinely performed on postoperative day (POD) 1, 3, 5-7. DAM values were compared between patients with postoperative AL versus patients without AL. A receiver-operating curve (ROC) with calculation of the areas under the ROC curves area under curves was performed and a cutoff value of DAM was calculated. Results: AL occurred in 25 patients (AL group) and 89 patients did not present AL (C group). The mean DAM was significantly higher in AL group versus C Group on POD 1, 3, and 5. A cutoff value of 307 IU/L predicted the occurrence of AL with a sensitivity and specificity of 91% and 100%, respectively. Positive and negative predictive values were 100% and 97.5%, respectively. Patients with AL had an elevated DAM prior to the appearance of any clinical signs of AL. Conclusion: High level DAM could accurately predict AL for proximal and distal digestive tract anastomoses. This simple, noninvasive, and low-cost method can accurately predict early AL and help physicians to perform appropriate imaging and treatment.

Long-Term Outcomes of Perioperative Versus Neoadjuvant Chemotherapy for Resectable Colorectal Liver Metastases: An International Multicentre Propensity-Score Matched Analysis with Stratification by Contemporary Risk-Scoring.

BACKGROUND: There is still debate regarding the principal role and ideal timing of perioperative chemotherapy (CTx) for patients with upfront resectable colorectal liver metastases (CRLM). This study assesses long-term oncological outcomes in patients receiving neoadjuvant CTx only versus those receiving neoadjuvant combined with adjuvant therapy (perioperative CTx). METHODS: International multicentre retrospective analysis of patients with CRLM undergoing liver resection between 2010 and 2015. Characteristics and outcomes were compared before and after propensity score matching (PSM). Primary endpoints were long-term oncological outcomes, such as recurrence-free survival (RFS) and overall survival (OS). Furthermore, stratification by the tumour burden score (TBS) was applied. RESULTS: Of 967 patients undergoing hepatectomy, 252 were analysed, with a median follow-up of 45 months. The unmatched comparison revealed a bias towards patients with neoadjuvant CTx presenting with more high-risk patients (p = 0.045) and experiencing increased postoperative complications ≥Clavien-Dindo III (20.9% vs. 8%, p = 0.003). Multivariable analysis showed that perioperative CTx was associated with significantly improved RFS (hazard ratio [HR] 0.579, 95% confidence interval [CI] 0.420-0.800, p = 0.001) and OS (HR 0.579, 95% CI 0.403-0.834, p = 0.003). After PSM (n = 180 patients), the two groups were comparable regarding baseline characteristics. The perioperative CTx group presented with a significantly prolonged RFS (HR 0.53, 95% CI 0.37-0.76, p = 0.007) and OS (HR 0.58, 95% CI 0.38-0.87, p = 0.010) in both low and high TBS patients. CONCLUSIONS: When patients after resection of CRLM are able to tolerate additional postoperative CTx, a perioperative strategy demonstrates increased RFS and OS in comparison with neoadjuvant CTx only in both low and high-risk situations.

Small Intestinal Neuroendocrine Neoplasm: Factors Associated with the Development of Local Tumor-Related Symptoms.

INTRODUCTION: Clinical presentations of small intestinal neuroendocrine neoplasms (SiNENs) can range from asymptomatic to life-threatening complications. Other than primary tumor(s), mesenteric mass (MM) can provide local tumor-related (LTR) symptoms. Although some expert centers propose routine primary resection to avoid complications in stage IV patients, some guidelines suggest avoiding primary tumor resection unless in the presence of symptoms. This study was aimed to identify factors associated with the presence or development of LTR symptoms. METHODS: From 2012 to 2019, SiNEN patients with appropriate initial morphological imaging were included. All initial imaging was reviewed. Associations between factors and LTR symptoms were assessed by logistic regression. RESULTS: Among 144 SiNEN patients, 66 met the inclusion criteria. Multivariate analysis identified on initial morphological imaging (i) any visible primary tumor (p < 0.01) and (ii) MM contact ≥180° with the superior mesenteric vessels (p ≤ 0.02), as independent factors associated with LTR symptoms in the whole study population as well as in the subgroup of primary resected patients. Among the 14 (21%) patients with both factors on initial cross-sectional conventional imaging, 12 (18%) were straightaway symptomatic at diagnosis and the remaining became symptomatic during the follow-up. All asymptomatic patients, without upfront surgery and without any predictive factor 16/18 (89%), stayed asymptomatic during the 2.7-year median follow-up. The absence of association between these 2 factors yielded a sensitivity of 100%, a specificity of 62%, and a negative predictive value of 100% for the occurrence of LTR symptoms. CONCLUSION: The presence of any visible primary tumor and/or MM superior mesenteric vessels contact ≥180° at initial cross-sectional imaging are 2 easily identifiable factors, which can help physicians for the decision-making regarding timing and type of surgery for SiNENs. Larger multicenter studies should endorse these results.

Liver resection for single large hepatocellular carcinoma: a prognostic factors study.

INTRODUCTION AND OBJECTIVES: Liver resection is the only curative therapeutic option for large hepatocellular carcinoma (> 5 cm), but survival is worse than in smaller tumours, mostly due to the high recurrence rate. There is currently no proper tool for stratifying relapse risk. Herein, we investigated prognostic factors before hepatectomy in patients with a single large hepatocellular carcinoma (HCC). MATERIAL AND METHODS: We retrospectively identified 119 patients who underwent liver resection for a single large HCC in 2 tertiary academic French centres and collected pre- and post-operative clinical, biological and radiological features. The primary outcome was overall survival at five years. Secondary outcomes were recurrence-free survival at five years and prognostic factors for recurrence. RESULTS: A total of 84% of the patients were male, and the median age was 66 years old (IQR 58-74). Thirty-nine (33%) had Child-Pugh A cirrhosis, and the mean Model for End-Stage Liver Disease (MELD) score was 6 (6-6). The aetiology of liver disease was predominantly alcohol-related (48%), followed by nonalcoholic steatohepatitis (22%), hepatitis B (18%) and hepatitis C (10%). The mean tumour size was 70 mm (55-110). The median overall survival was 72.5 months (IC 95%: 56.2-88.7), and the five-year overall survival was 55.1 ± 5.5%. The median recurrence-free survival was 26.6 months (95% CI: 16.0-37.1), and the five-year recurrence-free survival rate was 37.8 ± 5%. In multivariate analysis, preoperative prognostic factors for recurrence were baseline alpha-fetoprotein (AFP) > 7 ng/mL (p<0.001), portal veinous invasion (p=0.003) and cirrhosis (p=0.020). Using these factors, we created a simple recurrence-risk scoring system that classified three groups with distinct disease-free survival medians (p<0.001): no risk factors (65 months), 1 risk factor (36 months), and ≥2 risk factors (8.9 months). CONCLUSION: Liver resection is the only curative option for large HCC, and we confirmed that survival could be acceptable in experienced centres. Recurrence is the primary issue of surgery, and we proposed a simple preoperative score to help identify patients with the most worrisome prognosis and possible candidates for combined therapy.

Educational interventions to integrate surgical staff within medical units during the COVID-19 pandemic: EDUCOVID survey.

BACKGROUND: The SARS-CoV-2 (COVID-19) pandemic required a rapid surge of healthcare capacity to face a growing number of critically ill patients. For this reason, a support reserve of physicians, including surgeons, were required to be reassigned to offer support. OBJECTIVE: To realize a survey on the educational programs deployed (face-to-face or e-learning focusing on infective area, basic gestures, COVID clinical management and intensive care medicine), and their impact on behavior change (Kirkpatrick 3) of the target population of surgeons, measured on a five modalities Likert scale. DESIGN: Cross-sectional online e-survey (NCT04732858) within surgeons from the Assistance Publique - Hôpitaux de Paris network, metropolitan area of Paris, France. RESULTS: Cross-sectional e-Survey: among 382 surgeons invited, 37 (9.7%) participated. The effectiveness of the educational interventions on behavior changes was rated within the highest region of the Likert scale by 15% (n = 3) and 22% (n = 6) for 'e-learning' and 'face-to-face' delivery modes, respectively. CONCLUSIONS: Despite the low response rate, this survey suggests an overall low impact on behaviour change among responders affiliated to a surgical discipline.

Fully laparoscopic thermo-ablation of liver malignancies with or without liver resection: tumor location is an independent local recurrence risk factor.

BACKGROUND: The aim of this study was to analyze risk factors of local recurrence (LR) after exclusive laparoscopic thermo-ablation (TA) with or without associated liver resection. METHODS: Between 2012 and 2017, among 385 patients who underwent 820 TA in our department, 65 (17%) patients (HCC = 11, LM = 54) had exclusive laparoscopic TA representing 112 lesions (HCC = 17, LM = 95). TA was associated with other procedures in 57% of cases (liver resection 81%). All TA were done without liver clamping. Median tumor size was 1.8 cm [ranges from 0.3 to 4.5], 18% of the lesions were larger than 3 cm in size and 11% close to major liver vessels. Tumors locations were 77.5% in right liver, 36% in S7&S8, and 46% in S7&S8&S4a. RESULTS: Mortality was nil and morbidity rate 15.4% including Dindo-Clavien > II grade 3%. The median follow-up was 24 months [0.77-75]. Per lesion LR rate after TA was 18% (n = 19 patients) with a mean time of 7.6 months. Among patients with LR, 18 (95%) could have been re-treated successfully (new resection = 11, re-TA = 7). Multivariate analyses revealed that tumor location in S7 alone, S7&S8 and/or S7, S8, or S4a were independent risk factors of LR after TA. CONCLUSIONS: Exclusive laparoscopic TA is a safe and an effective tool to treat liver malignancies with or without liver resection. Other than classical risk factors, tumor location in upper segments of the liver, are independent risk factors for LR.

Perioperative chemotherapy versus surgery alone for resectable colorectal liver metastases: an international multicentre propensity score matched analysis on long-term outcomes according to established prognostic risk scores.

BACKGROUND: There is still uncertainty regarding the role of perioperative chemotherapy (CTx) in patients with resectable colorectal liver metastases (CRLM), especially in those with a low-risk of recurrence. METHODS: Multicentre retrospective analysis of patients with CRLM undergoing liver resection between 2010-2015. Patients were divided into two groups according to whether they received perioperative CTx or not and were compared using propensity score matching (PSM) analysis. Then, they were stratified according to prognostic risk scores, including: Clinical Risk Score (CRS), Tumour Burden Score (TBS) and Genetic And Morphological Evaluation (GAME) score. RESULTS: The study included 967 patients with a median follow-up of 68 months. After PSM analysis, patients with perioperative CTx presented prolonged overall survival (OS) in comparison with the surgery alone group (82.8 vs 52.5 months, p = 0.017). On multivariable analysis perioperative CTx was an independent predictor of increased OS (HR 0.705, 95%CI 0.705-0.516, p = 0.029). The benefits of perioperative CTx on survival were confirmed in patients with CRS and TBS scores ≤2 (p = 0.022 and p = 0.020, respectively) and in patients with a GAME score ≤1 (p = 0.006). CONCLUSION: Perioperative CTx demonstrated an increase in OS in patients with CRLM. Patients with a low-risk of recurrence seem to benefit from systemic treatment.

Preoperative magnetic resonance cholangiopancreatography before planned laparoscopic cholecystectomy: is it necessary?

BACKGROUND: The most feared complication of laparoscopic cholecystectomy (LC) is biliary tract injuries (BTI). We conducted a prospective study to evaluate the role of preoperative magnetic resonance cholangiopancreatography (MRCP) in describing the biliary tract anatomy and to investigate its potential benefit to prevent BTI. MATERIALS AND METHODS: From January 2012 to December 2016, 402 patients who underwent LC with preoperative MRCP were prospectively included. Routine intraoperative cholangiography was not performed. Patients' characteristics, preoperative diagnosis, biliary anatomy, conversion to laparotomy, and the incidence of BTI were analyzed. RESULTS: Preoperative MRCP was performed prospectively in 402 patients. LC was indicated for cholecystitis and pancreatitis, respectively, in 119 (29.6%) and 53 (13.2%) patients. One hundred and five (26%) patients had anatomical variations of biliary tract. Three BTI (0.75%) occurred with a major BTI (Strasberg E) and two bile leakage from the cystic stump (Strasberg A). For these 3 patients, biliary anatomy was modal on MRCP. No BTI occurred in patients presenting "dangerous" biliary anatomical variations. CONCLUSION: MRCP could be a valuable tool to study preoperatively the biliary anatomy and to recognize "dangerous" anatomical variations. Subsequent BTI might be avoided. Further randomized trials should be designed to assess its real value as a routine investigation before LC.

Portal Inflow Modulation by Somatostatin After Major Liver Resection: A Pilot Study.

: Major hepatectomy (MH) can lead to an increasing portal vein pressure (PVP) and to lesions of the hepatic parenchyma. Several reports have assessed the deleterious effect of a high posthepatectomy PVP on the postoperative course of MH. Thus, several surgical modalities of portal inflow modulation (PIM) have been described. As for pharmacological modalities, experimental studies showed a potential efficiency of Somatostatin to reduce PVP and flow. To our knowledge, no previous clinical reports of PIM using somatostatin are available. Herein, we report the results of PIM using somatostatin in 10 patients who underwent MH with post-hepatectomy PVP > 20 mmHg. Our results suggest Somatostatin could be considered as an efficient reversible PIM when PVP decrease is above 2.5 mmHg.

The liver hanging maneuver in laparoscopic liver resection: a systematic review.

PURPOSE: Laparoscopic surgery has gained the acceptance of the hepatobiliary surgical community and expert teams are now advocating major laparoscopic liver resections (LLRs). In this setting, the liver hanging maneuver (LHM) has been described in numerous series. We conducted a systematic review to investigate the effectiveness of the LHM in LLR. METHODS: We performed an electronic literature search using PubMed, EMBASE, and COCHRANE databases. The final search was carried out in December, 2015. RESULTS: We found 11 articles describing a collective total of 104 surgical procedures that were eligible for this study. Laparoscopic LHM was used in LLR for both benign and malignant conditions, and also in living donor liver transplantation (LDLT). The LHM was used mainly in right hepatectomy and only two authors reproduced the original LHM. We investigated the intraoperative parameters, preservation of postoperative liver function, and oncological outcomes. The clear benefit of using the LHM in LLR is for better identification of the parenchymal transection plane with less blood loss. The other benefits of LHM could not be corroborated by solid data on its positive value. CONCLUSIONS: In view of the data published in the literature, our findings are not strong enough to support the systematic use of LHM in LLR.

Laparoscopic treatment of a cephalic pancreatic leiomyoma.

BACKGROUND: Leiomyoma of the pancreas is very rare. Symptoms and signs are not specific. It has the clinical presentation of a pancreatic mass. The preoperative clinical and radiological assessments are fundamental to establish a therapeutic schema. The curative treatment is surgical resection. A methodical histological examination is required to confirm the final diagnosis of Leiomyoma. CASE REPORT: A 52-year-old female patient presented with a mass of the head of the pancreas. After preoperative assessment, the patient had laparoscopic enucleation. Postoperative course was no remarkable for complications. Pathology examination concluded to leiomyoma. CONCLUSION: Preoperative diagnosis of pancreatic leiomyoma is difficult. It has the features of a pancreatic mass. The preoperative assessment aims to identify signs of malignancy. In its absence, laparoscopy is feasible and safe. Enucleation, if indicated, is a surgical option for a benign disease sparing the patient a pancreatic resection.

Long term results of laparoscopic gastric band.

BACKGROUND: Laparoscopic gastric band (LAGB) has gained popularity among the surgical community since its first description in the early 90'. Actually, it is the third most practiced bariatric procedure in the world. The mean advantage of LAGB is a low rate of early postoperative morbidity. These satisfactory early results are in complete opposition with relatively high long term morbidity and a high rate of weight loss failure. AIM: Long term morbidity, weight loss and life quality index after LAGB were analyzed. METHODS: Data of patients eligible for LAGB between January 2005 and November 2016 in the surgical department of La Rabta teaching hospital were retrospectively analyzed. Weight loss curves, long term complications and quality of life were evaluated. RESULTS: Between 2004 and 2008, 28 patients had LAGB. Mean preoperative BMI was 44.6 Kg/m². No immediate complications occurred. Mean EWL were 39% and 37% respectively after 24 and 60 months. EWL was above 50% in only 4 patients. Coming to long term morbidity, 10 (35%) patients had complications. Reintervention rate was 39%. The gastric band was removed in 9 (32%) patients. Mean quality of life BAROS score was 4.21. CONCLUSIONS: Judging for its long term morbidity with a high reintervention rate, the LAGB raises the question of its valuable position as a surgical procedure against morbid obesity.

Fistulizing nodular lymphoid hyperplasia.

BACKGROUND: Nodular lymphoid hyperplasia (NLH) of the gastrointestinal (GI) tract is a rare condition in adults. It is usually asymptomatic. Few complications have been described. AIM:   We report an unusual clinical presentation of focal lymphoid hyperplasia of the GI. CASE REPORT: A 23-year-old female patient presented with a fistulizingdisease of the terminal ileum and the caecum complicated with an abscess of the lower right quadrant if the abdomen. CT-guided drainage with antibiotic therapy failed to control the abscess. Thus, surgery was undertaken and ileocaecal resection was performed. Focal lymphoid hyperplasia was confirmed by the pathology of the specimen. CONCLUSIONS: NLH is an uncommon condition in adults. To the best of our knowledge, no previous cases have been reported with fistulizing NLH. The management should follow the same algorithm as fistulizing ileitis. Surgery is indicated only in cases of complicated disease after the failure of medical treatment.

Laparoscopic ileo-cecal resection: the total retro-mesenteric approach.

BACKGROUND: Ileo-cecal resection is the most performed procedure in Cohn's disease. In the last decades, the laparoscopic approach became the gold standard. The dissection can be lateral to median or median to lateral. In non-malignant diseases as it is the case for Crohn's disease, the most performed dissection approach is the lateral to median. Herein, we describe a technique performed in our department: the total retro-mesenteric approach. METHOD: The procedure requires 4 trocars with a 10- to 12-mm median suprapubic trocar. The telescope is placed in this trocar. The dissection will begin with the opening of the mesentery root creating a retro-mesenteric tunnel. This dissection gives a direct visualization of the duodenum, of the ureter and the gonadic vessels which guarantees a safe procedure considering the importance of the inflammation in this disease. At the end of the retro-mesenteric step, the right colon is only attached to the Toldt's fascia. The transection of the mesentery is done next to the bowel wall leaving at the end the choice to the surgeon to perform an extra- or endocorporeal anastomosis. RESULTS: This retro-mesenteric approach has been used in our department since 2004. Until May 2013, 89 patients underwent laparoscopic resection for Crohn's disease with a mean operative time of 130 min, a morbidity rate of 6 % and a laparoconversion rate of 13.6 %. CONCLUSION: We describe the total retro-mesenteric approach in the ileo-cecal resection for Crohn's disease. The approach is considered to be safe allowing the surgeon to perform a dissection far from the inflammatory site and allowing a visual identification of the duodenum and the right ureter. The morbidity of the procedure is equivalent to the other dissection techniques.

Assessing the time-to-removal of totally implantable venous access devices comparing valved-versus open-ended catheters in patients treated with chemotherapy.

BACKGROUND: Totally IntraVenous Acess Devices (TIVAD) are used to have long-term bloodstream access. The catheter connected to the subcutaneous chamber may be valved (TIVAD-V) or open-ended (TIVAD-O). Infectious and occlusion complications require the removal of the TIVAD. We compared the two types of catheters (TIVAD-V and TIVAD-O) in terms of time-to-removal and complication rates. METHODS: A retrospective study of 636 patients treated for any malignancy using a TIVAD were included. TIVAD complication was defined as the occurrence of infection or occlusion requiring TIVAD removal. Risk factors of complications and time-to-removal of TIVAD were assessed by a Cox proportional hazard analysis. RESULTS: A total of 55 TIVADs (8.7%) were removed including 47 for infection and eight for occlusion in 54 months. There was no significant difference in the frequency of complications between TIVAD-V and TIVAD-O. There was no significant difference in time-to-removal between TIVAD-V and TIVAD-O (17.0 months, IQR [10.5-25.0] and 18.4 months, IQR [11.5-22.9], p = 0.345, respectively). CONCLUSION: There was no difference between TIVAD with valved and open catheter in terms of complications and time-to-removal in patients treated by chemotherapy.

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.