Intraoperative surgical margin re-resection for colorectal liver metastasis: is it worth the effort?

Relationship between hepatic surgical margins of colorectal cancer liver metastases and prognosis: A review

Colorectal cancer (CRC) remains a significant global health concern, as characterized by its high mortality rate ranking second among all the leading causes of death. The liver serves as the primary site of CRC metastasis, and the occurrence of liver metastasis is a significant contributor to mortality among patients diagnosed with CRC. The survival rate of patients with colorectal liver metastasis has significantly increased with the advancement of comprehensive tumor therapy. However, radical surgery remains the key factor. Since there are frequently multiple liver metastases, which are prone to recurrence after surgery, it is crucial to preserve as much liver parenchyma as possible without affecting the prognosis. The issue of surgical margins plays a crucial role in this regard. In this review, we begin by examining the occurrence of positive surgical margins in liver metastases of patients diagnosed with CRC. We aim to define positive margins in hepatic surgery, examine the relationship between margins and prognosis and establish a foundation for future research in this field.

Value and prognostic factors of repeat hepatectomy for recurrent colorectal liver metastasis

BACKGROUND

More than 50% of patients with colorectal cancer develop liver metastases. Hepatectomy is the preferred treatment for resectable liver metastases. This review provides a perspective on the utility and relevant prognostic factors of repeat hepatectomy in recurrent colorectal liver metastasis (CRLM).

DATA SOURCES

The keywords "recurrent colorectal liver metastases", "recurrent hepatic metastases from colorectal cancer", "liver metastases of colorectal cancer", "repeat hepatectomy", "repeat hepatic resection", "second hepatic resection", and "prognostic factors" were used to retrieve articles published in the PubMed database up to August 2020. Additional articles were identified by a manual search of references from key articles.

RESULTS

Despite improvements in surgical methods and perioperative chemotherapy, recurrence remains common in 37%-68% of patients. Standards or guidelines for the treatment of recurrent liver metastases are lacking. Repeat hepatectomy appears to be the best option for patients with resectable metastases. The commonly reported prognostic factors after repeat hepatectomy were R0 resection, carcinoembryonic antigen level, the presence of extrahepatic disease, a short disease-free interval between initial and repeat hepatectomy, the number (> 1) and size (≥ 5 cm) of hepatic lesions, requiring blood transfusion, and no adjuvant chemotherapy after initial hepatectomy. The median overall survival after repeat hepatectomy ranged from 19.3 to 62 months, and the 5-year overall survival ranged from 21% to 73%. Chemotherapy can act as a test for the biological behavior of tumors with the goal of avoiding unnecessary surgery, and a multimodal approach involving aggressive chemotherapy and repeat hepatectomy might be the treatment of choice for patients with early recurrent CRLM.

CONCLUSIONS

Repeat hepatectomy is a relatively safe and effective treatment for resectable recurrent CRLM. The presence or absence of prognostic factors might facilitate patient selection to improve short- and long-term outcomes.

Prognostic Impact of Surgical Margin Width in Hepatectomy for Colorectal Liver Metastasis

As for resection for colorectal liver metastasis (CRLM), securing an adequate surgical margin is important for achieving a better prognosis. However, it is often difficult to achieve adequate margins for the resection of CRLM. So the current survival impact of sub-centi/millimeter surgical margins in hepatectomy for CRLM should be evaluated. In the current era of multidisciplinary treatment options, this review focused on the prognostic impact of a sub-centi/millimeter surgical margin width in hepatectomy for CRLM. We systematically reviewed retrospective studies that clearly described the surgical margin width for hepatectomy for CRLM. We selected studies conducted since 2000 that involved patients diagnosed as having CRLM. We focused on studies that investigated not only surgical margins, but also microscopic surgical curability such as R0 (microscopically complete resection) or R1 (microscopically incomplete resection), which clearly describe their definitions. Based on our literature review, 1, 2, or 5 mm was considered the minimum surgical margin width for hepatectomy for CRLM. Although a surgical margin width of 1 mm is acceptable for hepatectomy for CRLM, submillimeter margins, which are defined as R1 in many reports, are only acceptable for limited patients such as those who have undergone preoperative chemotherapy. Zero-mm margins are also acceptable in limited patients such as those who show a good response to preoperative chemotherapy. New chemotherapy agents have been reported to reduce the prognostic impact of a narrow surgical margin width. The incidence of margin recurrence, which is a major concern regarding R1 resection of CRLM, is about 20-30% according to the majority of earlier reports. As evaluations of the actual prognostic impact of the surgical margin remain difficult, further study is warranted.

Higher Tumor Burden Status Dictates the Impact of Surgical Margin Status on Overall Survival in Patients Undergoing Resection of Intrahepatic Cholangiocarcinoma

BACKGROUND

The present study aimed to examine the prognostic significance of margin status following hepatectomy of intrahepatic cholangiocarcinoma (ICC) relative to overall tumor burden and nodal status.

METHOD

Patients who underwent curative-intent surgery for ICC between 1990 and 2017 were included from a multi-institutional database. The impact of margin status and width on overall survival (OS) was examined relative to TBS and preoperative nodal status.

RESULTS

Among 1105 patients with ICC who underwent resection, median tumor burden score (TBS) was 6.1 (IQR 4.2-8.8) and 218 (19.7%) patients had N1 disease. More than one in eight patients had an R1 surgical margin (n = 154, 13.9%). Among patients with low or medium TBS, an increasing margin width was associated with an incrementally improved 5-year OS (R1 31.9% vs. 1-3 mm 38.5% vs. 3-10 mm 48.0% vs. ≥ 10 mm 52.3%). In contrast, among patients with a high TBS, margin width was not associated with better survival (R1 28.9% vs. 1-3 mm 22.8% vs. 3-10 mm 29.6% vs. ≥ 10 mm 13.7%). In addition, surgical margin status did not impact survival with cutoffs of TBS 7 or greater. Furthermore, patients with low or medium TBS and preoperative negative lymph nodes derived a survival benefit from an R0 resection (R1 resection, HR 2.15, 95% CI 1.35-3.44, p = 0.001). In contrast, margin status was not associated with prognosis among patients with a high TBS and preoperative positive/suspicious lymph nodes (R1 resection, HR 1.34, 95% CI 0.58-3.11, p = 0.50).

CONCLUSION

R0 resection and wider margin resection resulted in improved outcomes in patients with low tumor burden; however, the survival benefit of negative margin status disappeared in patients with underlying poor tumor biology.

Analysis of survival factors after hepatic resection for colorectal cancer liver metastases: Does the R1 margin matter?

Introduction

The effect of liver margin on colorectal cancer liver metastases (CRLM) after hepatectomy has been controversial. In this study, we conducted a postoperative follow-up study of 205 patients with CRLM to clarify whether a positive margin is significant and to define the risk factors affecting CRLM survival.

Methods

The data of 205 patients with CRLM who underwent surgical treatment at the Third Hospital of Peking University in the Department of General Surgery from January 2009 to December 2020 were retrospectively analyzed. The general data, surgical data and postoperative follow-up of the patients were statistically analyzed.

Results

There were 130 cases (63.4%) of R0 resection and 75 cases (36.6%) of R1 resection. There were 136 males and 69 females, age 61 ± 11 years, and body mass index (BMI 24.5 ± 3.3 kg/m²). The overall survival rates at 1, 3, and 5 years for the entire cohort were 93.4%, 68.4%, and 45.5% in the R0 resection group vs. 93.2%, 53.7%, and 42% in the R1 resection group, respectively, which were not statistically significant (P = 0.520). The 1-, 3-, and 5-year disease-free survival rates of 63.2%, 33.3%, and 29.7% were significantly better in the R0 resection group than in the R1 resection group of 47.9%, 22.7%, and 17.7% (P = 0.016), respectively. After multivariable analysis, carbohydrate antigen 19-9 (CA19-9) > 39 U/ml (HR = 2.29, 95% CI: 1.39-3.79, P = 0.001), primary tumor perineural invasion (HR = 1.78, 95% CI: 1.01-3.13, P = 0.047), and BMI > 24 kg/m2 (HR = 1.75, 95% CI: 1.05-2.93, P = 0.033) were independently associated with poorer overall patient survival. The number of liver metastases >2 (HR = 1.65, 95% CI: 1.10-2.47, P = 0.016), the maximum diameter of metastases ≥50 mm (HR = 1.67, 95% CI: 1.06-2.64, P = 0.026), and vascular invasion of the primary tumor (HR = 1.65, 95% CI: 1.03-2.64, P = 0.038) were also independently associated with poorer disease-free survival.

Conclusion

In patients undergoing hepatectomy for CRLM, the negative effect of the R1 margin should be downplayed, and although the disease-free survival of the R1 margin is shorter than that of the R0 margin, it has no impact on overall survival. To improve overall survival, extra attention should be given to the factors of preoperative BMI, preoperative CA19-9, and the presence of perineural invasion of the primary tumor.

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

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.

Conclusion: Intraoperative assessment of RM- by surgeon of RLS is clinically meaningful. There is not a statistically significant difference in the assessment of RM+ by surgeon and pathologists per RLS, but it was statically significant on a per patient basis. RM determined by surgeon has better prognostic impact on recurrence rate and 1- and 3-year DFS than standard histopathological assessment.

Surgical treatment of colorectal liver metastasis

Liver metastasis is the most common form of distant metastasis in colorectal cancer and is a key factor for prognosis in patients with colorectal cancer. Surgery may be the only way to cure colorectal liver metastases. This paper mainly summarizes the latest progress in surgical treatment of colorectal liver metastases, including how to increase resection rate of liver metastases with neoadjuvant therapy or staged hepatectomy, the effect of surgical margin on the prognosis of patients, the timing of surgery in patients with synchronous colorectal liver metastasis, the impact of laparoscopic hepatectomy of liver metastases, the application of liver transplantation in patients with colorectal liver metastases, etc, with an aim to help develop an optimal treatment for patients with colorectal liver metastases through combination of surgical innovations with individualized treatment, thereby improving patients' disease-free survival and overall survival.

Colorectal liver metastases: An update on multidisciplinary approach

Liver metastasis is the commonest form of distant metastasis in colorectal cancer. Selection criteria for surgery and liver-directed therapies have recently been extended. However, resectability remains poorly defined. Tumour biology is increasingly recognized as an important prognostic factor; hence molecular profiling has a growing role in risk stratification and management planning. Surgical resection is the only treatment modality for curative intent. The most appropriate surgical approach is yet to be established. The primary cancer and the hepatic metastasis can be removed simultaneously or in a two-step approach; these two strategies have comparable long-term outcomes. For patients with a limited future liver remnant, portal vein embolization, combined ablation and resection, and associating liver partition and portal vein ligation for staged hepatectomy have been advocated, and each has their pros and cons. The role of neoadjuvant and adjuvant chemotherapy is still debated. Targeted biological agents and loco-regional therapies (thermal ablation, intra-arterial chemo- or radio-embolization, and stereotactic radiotherapy) further improve the already favourable results. The recent debate about offering liver transplantation to highly selected patients needs validation from large clinical trials. Evidence-based protocols are missing, and therefore optimal management of hepatic metastasis should be personalized and determined by a multi-disciplinary team.

R1 Resection for Colorectal Liver Metastases: a Survey Questioning Surgeons about Its Incidence, Clinical Impact, and Management

BACKGROUND

A ≥ 1-mm margin is standard for resection of colorectal liver metastases (CLM). However, R1 resection is not rare (10-30%), and chemotherapy could mitigate its impact. The possibility of detaching CLM from vessels (R1 vascular margin) has been described. A reappraisal of R1 resection is needed.

METHODS

A 19-question survey regarding R1 resection for CLM was sent to hepatobiliary surgeons worldwide. Seven clinical cases were included.

RESULTS

In total, 276 surgeons from 52 countries completed the survey. Ninety percent reported a negative impact of R1 resection (74% local recurrence, 31% hepatic recurrence, and 36% survival), but 50% considered it sometimes required for resectability. Ninety-one percent of responders suggested that the impact of R1 resection is modulated by the response to chemotherapy and/or CLM characteristics. Half considered the risk of R1 resection to be an indication for preoperative chemotherapy in patients who otherwise underwent upfront resection, and 40% modified the chemotherapy regimen when the tumor response did not guarantee R0 resection. Nevertheless, 80% scheduled R1 resection for multiple bilobar CLM that responded to chemotherapy. Forty-five percent considered the vascular margin equivalent to R0 resection. However, for lesions in contact with the right hepatic vein, right hepatectomy remained the standard. Detachment from the vein was rarely considered (10%), but 27% considered detachment in the presence of multiple bilobar CLM.

CONCLUSIONS

A negative margin is still standard for CLM, but R1 resection is no longer just a technical error. R1 resection should be part of the modern multidisciplinary, aggressive approach to CLM.

The Prognostic Value of Varying Definitions of Positive Resection Margin in Patients with Colorectal Cancer Liver Metastases

BACKGROUND

Varying definitions of resection margin clearance are currently employed among patients with colorectal cancer liver metastases (CRLM). Specifically, a microscopically positive margin (R1) has alternatively been equated with an involved margin (margin width = 0 mm) or a margin width < 1 mm. Consequently, patients with a margin width of 0-1 mm (sub-mm) are inconsistently classified in either the R0 or R1 categories, thus obscuring the prognostic implications of sub-mm margins.

METHODS

Six hundred thirty-three patients who underwent resection of CRLM were identified. Both R1 definitions were alternatively employed and multivariable analysis was used to determine the predictive power of each definition, as well as the prognostic implications of a sub-mm margin.

RESULTS

Five hundred thirty-nine (85.2%) patients had a margin width ≥ 1 mm, 42 had a sub-mm margin width, and 52 had an involved margin (0 mm). A margin width ≥ 1 mm was associated with improved survival vs. a sub-mm margin (65 vs. 36 months; P = 0.03) or an involved margin (65 vs. 33 months; P < 0.001). No significant difference in survival was detected between patients with involved vs. sub-mm margins (P = 0.31). A sub-mm margin and an involved margin were both independent predictors of worse OS (HR 1.66, 1.04-2.67; P = 0.04, and HR 2.14, 1.46-3.16; P < 0.001, respectively) in multivariable analysis. Importantly, after combining the two definitions, patients with either an involved margin or a sub-mm margin were associated with worse OS in multivariable analysis (HR 1.94, 1.41-2.65; P < 0.001).

CONCLUSIONS

Patients with involved or sub-mm margins demonstrated a similar inferior OS vs. patients with a margin width > 1 mm. Consequently, a uniform definition of R1 as a margin width < 1 mm should perhaps be employed by future studies.

[Surgical innovations in treatment of metastatic colorectal cancer : Complexity of metastatic surgery as example for personalized medicine]

BACKGROUND

Extensive, bilobular and multifocal colorectal liver metastases (CLM) or metastases that are critically situated require an experienced surgeon and advanced surgical techniques to enable curative resection.

OBJECTIVE

This article describes the toolbox of hepato-oncologic surgery including functional augmentation of liver segments by portal vein embolization/ligation, combinations of ablation and resection, two-stage resections and in situ split liver resection, also known as associating liver partition and portal vein ligation for staged hepatectomy (ALPPS). Furthermore, the curative resection of extrahepatic, oligometastatic disease are briefly discussed.

MATERIAL AND METHODS

Review of current literature as well as discussion of the ALPPS procedure, which was developed at our institute.

RESULTS

In recent years, oncologic resections for CLM have been significantly refined, leading to a constant increase of curative resection rates.

CONCLUSION

In a multimodality treatment setting, surgical resection of CLM remains the gold standard curative approach and even in the event of presumed hopeless cases with extensive metastasis, experienced hepatobiliary surgeons must evaluate the resectability of colorectal metastases.

Prognostic influence of hepatic margin after resection of colorectal liver metastasis: role of modern preoperative chemotherapy

PURPOSE

Modern chemotherapy (CTX) increases survival in stage IV colorectal cancer. In colorectal liver metastases (CLM), neoadjuvant (neo) CTX may increase resectability and improve survival. Due to widespread use of CTX in CLM, recent studies assessed the role of the hepatic margin after CTX, with conflicting results. We evaluated the outcome after resection of CLM in relation to CTX and hepatic resection status.

METHODS

Since 2000, 334 patients with first hepatic resection for isolated CLM were analyzed. Thirty-two percent had neoadjuvant chemotherapy (targeted therapy in 42%). Sixty-eight percent never had CTX before hepatectomy or longer than 6 months before resection. The results were gained by analysis of our prospective database.

RESULTS

Positive hepatic margins occurred in 8% (independent of neoCTx). Patients after neoCTX had higher numbers of CLM (p < 0.01) and a longer duration of surgery (p < 0.03). After hepatectomy, 5-year survival was 45% and correlated strongly with the margin status (47% in R-0 and 21% in R-1; p < 0.001). Survival also correlated with margin status in the subgroups with neoCTX (p < 0.01) or without neoCTx (p < 0.01). In multivariate analysis of the entire group, hepatic margin status (RR 3.2; p < 0.001) and age > 65 years (RR 1.6; p < 0.01) were associated with poorer survival. In the subgroup of patients after neoCTX (n = 106), only the resection margin was an independent predictor of survival (p < 0.001).

CONCLUSION

In patients with isolated colorectal liver metastases undergoing resection, the hepatic margin status was the strongest independent prognostic factor. This effect was also present after neoadjuvant chemotherapy for CLM.

The Prognostic Impact of Determining Resection Margin Status for Multiple Colorectal Metastases According to the Margin of the Largest Lesion

BACKGROUND

Although the prognostic role of surgical margin status after resection of colorectal liver metastasis (CRLM) has been previously examined, controversy still surrounds the importance of surgical margin status in patients with multiple tumors.

METHODS

Patients who underwent curative-intent surgery for CRLM from 2000 to 2015 and who presented with multiple tumors were identified. Patients with R1 resection status determined by the closest resection margin of the non-largest tumor were classified as R1-Type 1; patients with R1 status determined by the resection margin of the largest tumor were defined as R1-Type 2. Data regarding surgical margin status, size of tumors, and overall survival (OS) were collected and assessed.

RESULTS

A total of 251 patients met inclusion criteria; 156 patients (62.2%) had a negative margin (R0), 50 had an R1-type 1 (19.9%), and 45 had an R1-type 2 (17.9%) margin. Median and 5-year OS in the entire cohort was 56.4 months and 48.0%, respectively. When all R1 (Type 1 + Type 2) patients were compared with R0 patients, an R1 was not associated with worse prognosis (P = 0.05). In contrast, when R1-type 2 patients were compared with R0 patients, an R1 was strongly associated with worse OS (P = 0.009). On multivariate analysis, although the prognostic impact of all R1 was not associated with OS (hazard ratio [HR] 1.56; P = 0.08), R1-Type 2 margin status independently predicted a poor outcome (HR 1.93; P = 0.03).

CONCLUSIONS

The impact of margin status varied according to the size of the tumor assessed. While R1 margin status defined according to the non-largest tumor was not associated with OS, R1 margin status relative to the largest index lesion was associated with prognosis.

Predictive factors for bile leakage after hepatectomy for hepatic tumors: a retrospective multicenter study with 631 cases at Yokohama Clinical Oncology Group (YCOG)

BACKGROUND

International Study Group of Liver Surgery (ISGLS) proposed the standardized definition for bile leakage (BL) after hepatectomy (Hx) at 2011 to precisely perceive incidence and predictive factors of this critical condition.

METHODS

We conducted a multicenter retrospective study using the ISGLS definition of BL after Hx.

RESULTS

Perioperative data regarding 631 patients undergoing elective Hx for hepatic tumors without biliary reconstruction performed between January 2009 and December 2011 were analyzed. BL was observed in 30 patients (4.8%). (Grade A, 8 (1.3%); B, 21(3.3%); C, 1 (0.2%)). Five independent predictors (diagnosis of liver metastases, prolonged operation, high risk procedures defined as Hx with broad exposure of the hilar Glissonean sheath, low platelet count and high serum total bilirubin on postoperative day 1) for grade B/C BL were elucidated by the multivariate analysis. When the study cohorts were divided into groups by number of accompanying these predictors, the more the accompanying independent predictors, the higher the incidence of BL. Notably, incidence of BL exceeded 40% in patients with four or more of these predictors.

CONCLUSIONS

Risk stratification for BL after Hx can be achievable using independent predictors clarified in this study. However, proper management for high risk patients remains to be elucidated.

Perioperative Hyperglycemia and Postoperative Outcomes in Patients Undergoing Resection of Colorectal Liver Metastases

INTRODUCTION

There is limited evidence characterizing the impact of glycemic alterations on short-term outcomes among patients undergoing resection of colorectal liver metastases (CRLM).

METHODS

Hyperglycemia was defined as a glucose value >125 mg/dl according to WHO definition. The impact of early postoperative hyperglycemia on short-term postoperative outcomes was assessed.

RESULTS

The mean postoperative glucose value was 128 mg/dl; 30 (9.8 %) patients had normal fasting glucose (<100 mg/dl), 106 patients had glucose intolerance (100-125 mg/dl), and 170 (55.5 %) patients had hyperglycemia (>125 mg/dl). A postoperative complication occurred in 101 patients (morbidity, 33.1 %); among patients who experienced a complication, an infectious complication was most common (38.6 %). After controlling for clinical factors, patients with hyperglycemia had an increased risk of overall complications [odds ratio (OR) 4.11; 95 % confidence interval (CI) 1.96-8.62, P < 0.001]. This was the case for both patients with and without diabetes (P < 0.05). Patients with hyperglycemia on the day of surgery were also at an increased risk of infections [OR 9.17; 95 % CI 2.26-37.13, P = 0.002] and had a longer hospital stay (normal glucose, 4 days vs. glucose 100-125 mg/dl, 4 days vs. glucose >125 mg/dl, 5 days, P < 0.001).

CONCLUSIONS

Early postoperative hyperglycemia was associated with adverse outcomes in patients with and without diabetes who underwent resection of CRLM. Perioperative glucose evaluation may be an important quality target.

Tumor Biology Rather Than Surgical Technique Dictates Prognosis in Colorectal Cancer Liver Metastases

INTRODUCTION

The interplay of tumor biology and surgical margin status after resection for colorectal liver metastasis (CRLM) remains controversial. Consequently, we sought to determine the impact of surgical margin status on overall survival (OS) stratified by KRAS mutational status.

MATERIALS AND METHODS

Four hundred eighty-five patients with known KRAS mutational status were identified. Clinicopathologic and long-term survival data were collected and assessed.

RESULTS

On pathology, most patients (n = 380; 78.3 %) had an R0 margin, while 105 (21.7 %) had an R1. Roughly two thirds of tumors were KRAS wild type (wtKRAS) (n = 307, 63.3 %), while 36.7 % (n = 178) had KRAS mutations (mutKRAS). Median and 5-year OS of the entire cohort was 65.8 months and 53.8 %, respectively. An R1 resection was associated with worse 5-year OS compared with R0 (42.4 % vs. 57.1 %; hazard ratio (HR) 1.82, 95 % CI 1.28-2.57; P = 0.001). After controlling for KRAS status, the survival benefit associated with an R0 resection persisted only among patients with wtKRAS tumors (HR 2.16, 95 % CI 1.42-3.30; P < 0.001). In contrast, surgical margin had no impact on OS among patients with mutKRAS tumors (5-year OS R0, 40.7 % vs. R1, 46.7 %; HR 1.34, 95 % CI 0.73-2.48; P = 0.348).

CONCLUSION

The impact of margin status differed by KRAS mutation status. An R0 margin only provided a survival benefit to patients with wtKRAS tumors. Tumor biology and not surgical technique determined prognosis.

Management of patients with colorectal liver metastasis in eleven questions and answers

INTRODUCTION

Colorectal liver metastasis (CRLM) is the most frequent indication for liver resection in many centers. Recent improvements in oncology, surgery, interventional radiology, pathology and anesthesiology allow curative treatment in a larger proportion of patients with CRLM. Areas covered: We illustrate the various aspects of the management of CRLM through 11 questions that summarize the topic, from the current obtained survival to future perspectives such as transplantation. The limits of a curative treatment are also presented from different angles, such as the benefits of pathology, the surgical options for extreme resections, the available chemotherapies and their efficacy, or the non-surgical ablative treatments. Expert commentary: Given the increasing therapeutic possibilities, we strengthen the importance to analyze the situation of each patient with CRLM in a dedicated multidisciplinary team, in order to offer the best individualized treatment combination.

KRAS Mutation Status Dictates Optimal Surgical Margin Width in Patients Undergoing Resection of Colorectal Liver Metastases

BACKGROUND

The optimal tumor-free margin width remains controversial and may be inappropriate to investigate without considering differences in the underlying tumor biology.

METHODS

R1 resection was defined as margin clearance less than 1 mm. R0 resection was further divided into 3 groups: 1-4, 5-9, and ≥10 mm. The impact of margin width on overall survival (OS) relative to KRAS status [wild type (wtKRAS) vs. mutated (mutKRAS)] was assessed.

RESULTS

A total of 411 patients met inclusion criteria. Median patient age was 58 years (interquartile range, 49.7-66.7); most patients were male (n = 250; 60.8 %). With a median follow-up of 28.3 months, median and 5-year OS were 69.8 months and 55.1 %. Among patients with wtKRAS tumors, although margin clearance of 1-4 mm or more was associated with improved OS compared to R1 (all P < 0.05), no difference in OS was observed when comparing margin clearance of 1-4 mm to the 5-9 mm and the ≥10 mm groups (all P > 0.05). In contrast, among patients with mutKRAS tumors, all three groups of margin clearance (1-4, 5-9, and ≥10 mm) fared no better in terms of 5-year survival compared to R1 resection (all P > 0.05).

CONCLUSIONS

While a 1-4 mm margin clearance in patients with wtKRAS tumors was associated with improved survival, wider resection width did not confer an additional survival benefit. In contrast, margin status-including a 1 cm margin-did not improve survival among patients with mutKRAS tumors.

Impact of surgical margin clearance for resection of secondary hepatic malignancies

Over the past several decades, there has been increasing discussion regarding the optimal management of secondary liver malignancies. Traditionally, resection has only been recommended if it could be accomplished with negative microscopic margins of at least 10 mm. However, many investigators have pushed this limit to offer resection to patients with narrower margins. We review the data regarding the impact of margin clearance on outcomes for patients undergoing hepatic metastasectomy.

Negative surgical margin improved long-term survival of colorectal cancer liver metastases after hepatic resection: a systematic review and meta-analysis

OBJECTIVE

The need to achieve a tumor-free margin of ≥1 mm (R0) for colorectal liver metastases (CRLM) after hepatic resection has been questioned recently. This study conducted a meta-analysis to determine whether status of the surgical margin still influenced the long-term outcome of survival and recurrence rate.

METHODS

Eligible trials that compared survival and recurrence rates of R0 versus the tumor-free margin <1 mm (R1) were identified from Embase, PubMed, the Web of Science, and the Cochrane Library since their inception to 1 March 2015. The study outcomes included long-term outcome of survival and recurrence rate. Hazard ratio (HR) with a 95 % confidence interval was used to measure the pooled effect according to a random-effects model or fixed-effects model, depending on the heterogeneity among the included studies. The heterogeneity among these trials was statistically evaluated using the χ(2) and I(2) tests. Sensitivity analyses and publication bias were also carried out.

RESULTS

A total of 18 studies containing 6790 patients were included. The comparison between R1 and R0 revealed that a pooled HR for 5-year overall survival was 1.603 (95 % CI; 1.464-1.755; p = 0.000; I(2) = 31.2 %, p = 0.141). For patients received modern chemotherapy; a pooled HR of R1 resection for 5-year overall survival was 1.924 (95 % CI; 1.567-2.361, p = 0.000; I(2) = 20.5 %, p = 0.273). The pooled HR for 5-year OS of ≥1 cm in the included studies calculated using the random-effects model was 0.819 (95 % CI; 0.715-0.938, p = 0.004; I(2) = 0 %, p = 0.492).

CONCLUSIONS

R1 resections decreased long-term survival, and modern chemotherapy did not alter an adverse outcome. Surgeons should attempt to obtain a 1-cm margin.

Adrenocortical Carcinoma: Impact of Surgical Margin Status on Long-Term Outcomes

BACKGROUND

The influence of surgical margin status on long-term outcomes of patients undergoing adrenal resection for ACC remains not well defined. We studied the impact of surgical tumor margin status on recurrence-free survival (RFS) and overall survival (OS) of patients undergoing resection for ACC.

METHODS

A total of 165 patients who underwent adrenal resection for ACC and met inclusion criteria were identified form a multi-institutional database. Clinicopathological data, pathologic margin status, and long-term outcomes were assessed. Patients were stratified into two groups based on margin status: R0 (margin >1 mm) versus R1.

RESULTS

R0 resection was achieved in 126 patients (76.4 %), whereas 39 patients (23.6 %) had an R1 resection. Median and 5-year OS for patients undergoing R0 resection were 96.3 months and 64.8 % versus 25.1 months and 33.8 % for patients undergoing an R1 resection (both p < 0.001). On multivariable analysis, surgical margin status was an independent predictor of worse OS (hazard ratio [HR] 2.22, 95 % confidence interval [CI] 1.03-4.77; p = 0.04). The incidence of recurrence also differed between the two groups; 5-year RFS was 30.3 % among patients with an R0 resection versus 13.8 % among patients who had an R1 resection (p = 0.03). Lymph node metastasis (N1) was an independent predictor of RFS (HR 2.70, 95 % CI 1.04-6.99; p = 0.04).

CONCLUSIONS

A positive margin after ACC resection was associated with worse long-term survival. Patient selection and an emphasis on surgical technique to achieve R0 margins are pivotal to optimizing the best chance for long-term outcome among patients with ACC.