Genomic profiling of idiopathic peri-hilar cholangiocarcinoma reveals new targets and mutational pathways.

Peri-hilar cholangiocarcinoma (pCCA) is chemorefractory and limited genomic analyses have been undertaken in Western idiopathic disease. We undertook comprehensive genomic analyses of a U.K. idiopathic pCCA cohort to characterize its mutational profile and identify new targets. Whole exome and targeted DNA sequencing was performed on forty-two resected pCCA tumors and normal bile ducts, with Gene Set Enrichment Analysis (GSEA) using one-tailed testing to generate false discovery rates (FDR). 60% of patients harbored one cancer-associated mutation, with two mutations in 20%. High frequency somatic mutations in genes not typically associated with cholangiocarcinoma included mTOR, ABL1 and NOTCH1. We identified non-synonymous mutation (p.Glu38del) in MAP3K9 in ten tumors, associated with increased peri-vascular invasion (Fisher's exact, p < 0.018). Mutation-enriched pathways were primarily immunological, including innate Dectin-2 (FDR 0.001) and adaptive T-cell receptor pathways including PD-1 (FDR 0.007), CD4 phosphorylation (FDR 0.009) and ZAP70 translocation (FDR 0.009), with overlapping HLA genes. We observed cancer-associated mutations in over half of our patients. Many of these mutations are not typically associated with cholangiocarcinoma yet may increase eligibility for contemporary targeted trials. We also identified a targetable MAP3K9 mutation, in addition to oncogenic and immunological pathways hitherto not described in any cholangiocarcinoma subtype.

Prognosis and Circumferential Margin in Patients with Resected Hilar Cholangiocarcinoma.

BACKGROUND: Resection margin status is a known prognosticator in patients who undergo resection for hilar cholangiocarcinoma. However, the influence of an isolated positive circumferential margin on clinical outcome is unclear. METHODS: Patients with resected de novo hilar cholangiocarcinoma from two European hepatobiliary centres (Medical University of Vienna and Aintree University Hospital, 2006-2016) were classified according to resection margin status (negative, surgically positive, isolated circumferentially positive) and investigated with respect to overall survival (OS), recurrence-free survival (RFS) and recurrence pattern. RESULTS: Eighty-three (48 male/35 female) patients were enrolled. The median age was 64 years (range 33-80). The median follow-up was 21.7 months (range 0.3-92.4). Forty (48%) patients had negative resection margins, 25 (30%) had an isolated positive circumferential margin and 18 (22%) had a positive surgical margin. The 5-year OS rates in patients with negative, isolated positive circumferential and positive surgical resection margins were 47%, 33% and 0%, respectively. Median OS was 45.6, 32.7 and 14.5 months, respectively (log rank, P = 0.011). Upon multivariable Cox regression analysis, resection margin status and lymph node status remained statistically significant (P < 0.05). No difference with respect to RFS and recurrence pattern was found between the groups (P > 0.05). CONCLUSION: Our data show that these three resection margin types were associated with different clinical outcomes. Circumferential margin status may therefore serve as a novel prognostic biomarker.

Robotic Surgery for Malignant Liver Disease: a Systematic Review of Oncological and Surgical Outcomes.

Robot-assisted laparoscopic surgery is yet another modification of minimally invasive liver surgery. It is described as feasible and safe from the surgical point of view; however, oncological outcomes need to be adequately analysed to justify the use of this technique when resecting malignant liver tumours. We reviewed existing English medical literature on robot-assisted laparoscopic liver surgery. We analysed surgical outcomes and oncological outcomes. We analysed operative parameters including operative time, type of hepatectomy, blood loss, conversion rate, morbidity and mortality rates and length of stay. We also analysed oncological outcomes including completeness of resection (R status), recurrence, survival and follow-up data. A total of 582 patients undergoing robot-assisted laparoscopic liver surgery were analysed from 17 eligible publications. Only 5 publications reported survival data. The overall morbidity was 19% with 0.2% reported mortality. R0 resection was achieved in 96% of patients. Robotic liver surgery is feasible and safe with acceptable morbidity and oncological outcomes including resection margins. However, well-designed trials are required to provide evidence in terms of survival and disease-free intervals when performed for malignancy.

Shanghai international consensus on diagnosis and comprehensive treatment of colorectal liver metastases (version 2019).

The liver is the most common anatomical site for hematogenous metastases from colorectal cancer. Therefore effective treatment of liver metastases is one of the most challenging elements in the management of colorectal cancer. However, there is rare available clinical consensus or guideline only focusing on colorectal liver metastases. After six rounds of discussion by 195 clinical experts of the Shanghai International Consensus Expert Group on Colorectal Liver Metastases (SINCE) from 29 countries or regions, the Shanghai Consensus has been finally completed, based on current research and expert experience. The consensus emphasized the principle of multidisciplinary team, provided detailed diagnosis approaches, and guided precise local and systemic treatments. This Shanghai Consensus might be of great significance to standardized diagnosis and treatment of colorectal liver metastases all over the world.

Prognostic and predictive markers in liver limited stage IV colorectal cancer.

Colorectal cancer is the third most commonly diagnosed cancer among both men and women. Personalised treatment options remain complex, although there is broad agreement over which patients with colorectal liver metastases (CRLM) should and should not be offered resection. Decisions on an optimal management strategy involves careful assessment of both technical and oncological factors. In this review we aim to summarise current prognostic biomarkers for metastatic colorectal cancers, specifically patients considered for resection. A number of clinico-pathological factors have been identified as prognostically important with good internal validity, but limited external validity. Furthermore, these prognostic scoring systems do not take factor in modern chemotherapeutic agents and the disease modification these agents produce. Histopathological response to chemotherapy is of significant prognostic importance. Molecular markers can help predict the efficacy of a biological agent. An important prognostic factor of liver metastasis is the recognition that location of the primary colorectal cancer impacts on metastatic phenotype and represents difference in genotype, i.e. proximal tumours are more aggressive than distal tumours with an increased likelihood of disease progression. Several mutational molecular markers identified include microsatellite instability, BRAF, and KRAS/NRAS and combination mutations, which confer poorer outcomes. Accurate prognostication in patients with liver limited colorectal metastases remains crucial, as this allows tailoring treatment options to each disease and improving outcomes. Access to tissue before treatment remains a limitation although advances in ability to assess tumour biology by non-invasive methods are promising.

Building a collaboration to improve surgical research through EORTC/ESSO 1409-CLIMB study: A prospective liver metastasis database with an integrated quality assurance program.

The challenges of conducting surgical oncology trials have resulted to low quantity and poor quality research [1,2]. Considering the definitive role of surgery to offer cure, immediate response to improve surgical research is needed [3]. The European Organization for Research and Treatment of Cancer (EORTC) and the European Society of Surgical Oncology (ESSO) share the vision to achieve excellent surgical research and care for cancer patients. Building on their complimentary expertise, they embarked on a pilot project to map out challenges and initiate a sustainable collaboration to advance cancer surgery research in Europe. This pilot project is EORTC-ESSO 1409 GITCG/ ESSO-01: A Prospective Colorectal Liver Metastasis Database with an Integrated Quality Assurance Program (CLIMB). This article will describe the challenges, milestones and vision of both organizations in setting up this collaboration.

Evaluation of the utility of prognostic models for patients with resected hilar cholangiocarcinoma.

BACKGROUND: Several prognostic systems have been proposed to guide management strategies post-resection for patients with hilar cholangiocarcinoma. The objective of this study was to evaluate the efficacy of these conventional prognostic models, with respect to Overall Survival (OS), on patients in a modern single-centre resectional cohort. METHOD: Patients diagnosed with hilar cholangiocarcinoma, referred to a supra-regional tertiary referral centre between February 2009 and February 2016, were retrospectively analysed from a prospectively held database linked to Hospital Episode Statistics and Somerset Cancer Registry data. RESULTS: Two-hundred and one patients were assessed for suitability for surgery. Eighty-three (41%) patients considered to have potentially resectable disease underwent surgical assessment of resectability. Fifty-six (68%) patients proceeded to resection. Multivariate analysis demonstrated that pre-operative Serum CA 19-9 (p = 0.007), Radiological Arterial Involvement (p = 0.005) and Amsterdam Medical Centre (AMC) prognostic model score (p = 0.032) retained significance in association with OS. Multivariate models developed from this cohort out-performed the conventional prognostic systems for OS. CONCLUSION: The cohort-derived multivariate models demonstrated significantly improved prognostic capability compared to conventional systems in explaining OS.

Multicentre validation of a clinical prognostic score integrating the systemic inflammatory response to the host for patients treated with curative-intent for colorectal liver metastases: The Liverpool score.

BACKGROUND: This study aimed to create a new prognostic score integrating the systemic inflammatory response to predict survival in patients treated with curative intent for colorectal liver metastases (CLM). METHODS: We identified independent prognostic factors in patients who underwent liver surgery for CLM in a tertiary centre in the United Kingdom (UK) between 2010 and 2015. A pre- and a postoperative score (Liverpool score) were created by combining these factors to stratify patients into different risk groups. These new scores were validated in an international cohort of 219 patients from China and France. RESULTS: Multivariate cox regression analysis of the 364 patients of the UK cohort identified 6 preoperative and 1 postoperative prognostic factors for overall survival (OS): American society of anaesthesiologists (ASA) score, location and node status of the primary tumour, number and size of CLM, neutrophil-to-lymphocyte ratio (NLR) and resection margin. Both pre- and postoperative scores can be calculated with an online calculator at https://jscalc.io/calc/PXatrmjfrEFpYy2t. Using the pre-operative model on the UK cohort, median OS was 61.22 (50.23, not reached) months in the low-risk group (n = 162) and 30.36 (23.68, 35.95) months in the high-risk group (n = 162, p < 0.0001). The same difference was observed in the validation cohort. The Liverpool score outperformed previously published scoring system with a c-index of 0.619 pre-operatively and of 0.637 post-operatively. CONCLUSION: We developed a new prognostic score based on clinicopathologic characteristics including the site of the primary tumour location and on measurement of the systemic inflammatory response which could help to tailor patients' management.

Reshaping the critical role of surgeons in oncology research.

Surgery remains a mainstay in the treatment of most solid cancers. Surgeons have always engaged in various forms of high-quality cancer research to optimize outcomes for their patients, for example, contributing to clinical research and outcomes research as well as health education and public health policy. Over the past decade, however, concerns have been raised about a global decline in the number of surgeons performing basic science research alongside clinical activity - so-called surgeon scientists. Herein, we describe some of the unique obstacles faced by contemporary trainee and practising surgeons engaged in research, as well as providing a perspective on the implications of the diminishing prominence of the surgeon scientist. Finally, we offer some thoughts on potential strategies and future directions for surgical engagement in oncology research to increase the number of research-active surgeons.

Preoperative Leucocyte-Based Inflammatory Scores in Patients with Colorectal Liver Metastases: Can We Count on Them?

BACKGROUND: Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR) have been identified as potential prognostic factors for overall survival (OS) in primary colorectal cancer, and there is a growing interest in their use in colorectal liver metastases (CLMs). However, optimal cut-off values for these ratios have not been defined by making comparison between series difficult. This study aimed to confirm the prognostic value of inflammatory scores in patients undergoing resection for CLM. METHODS: We retrospectively analysed data from 376 consecutive patients who underwent liver surgery for CLM between June 2010 and August 2015. We assessed the reproducibility of previously published ratios and determined new cut-off values using the Cut-off Finder web-based tool. Relations between cut-off values and OS were analysed with Kaplan-Meier log-rank survival analysis and multivariate Cox models. RESULTS: Three hundred and forty-three patients had full preoperative blood tests for calculation of NLR, PLR and LMR. The number of cut-off values which showed a significant discrimination for OS was 49/249 (19.7%) for NLR, 28/316 (8.9%) for PLR and 22/214 (10.3%) for LMR, all with a scattered nonlinear distribution. CONCLUSIONS: This study showed that inflammatory scores expressed as ratios do not seem to be consistently reliable prognostic markers in patients with resectable CLM.

RAS Mutation Clinical Risk Score to Predict Survival After Resection of Colorectal Liver Metastases.

OBJECTIVE: To determine the impact of RAS mutation status on the traditional clinical score (t-CS) to predict survival after resection of colorectal liver metastases (CLM). BACKGROUND: The t-CS relies on the following factors: primary tumor nodal status, disease-free interval, number and size of CLM, and carcinoembryonic antigen level. We hypothesized that the addition of RAS mutation status could create a modified clinical score (m-CS) that would outperform the t-CS. METHODS: Patients who underwent resection of CLM from 2005 through 2013 and had RAS mutation status and t-CS factors available were included. Multivariate analysis was used to identify prognostic factors to include in the m-CS. Log-rank survival analyses were used to compare the t-CS and the m-CS. The m-CS was validated in an international multicenter cohort of 608 patients. RESULTS: A total of 564 patients were eligible for analysis. RAS mutation was detected in 205 (36.3%) of patients. On multivariate analysis, RAS mutation was associated with poor overall survival, as were positive primary tumor lymph node status and diameter of the largest liver metastasis >50 mm. Each factor was assigned 1 point to produce a m-CS. The m-CS accurately stratified patients by overall and recurrence-free survival in both the initial patient series and validation cohort, whereas the t-CS did not. CONCLUSIONS: Modifying the t-CS by replacing disease-free interval, number of metastases, and CEA level with RAS mutation status produced an m-CS that outperformed the t-CS. The m-CS is therefore a simple validated tool that predicts survival after resection of CLM.

Clinical outcome after resection of early-stage hilar cholangiocarcinoma.

BACKGROUND: Liver transplantation in patients with unresectable early-stage (<3 cm, node negative) hilar cholangiocarcinoma has been recently reported to be associated with longer survival compared to liver resection and therefore suggested as potential treatment option also in resectable disease. Here, we investigated the outcome of resection in early-stage tumours as the standard of care in an experienced European centre. METHODS: Patients with de novo resectable hilar cholangiocarcinomas who underwent liver resection between mid-2009 and December 2017 were classified as early-stage (<3 cm and node negative) or later-stage tumours (≥3 cm and/or node positive), and were investigated with respect to clinical outcome. RESULTS: Fifty-six patients were analyzed of whom 17 had early-stage tumours and 39 had later-stage tumours. The sex ratio (m:f) was 30:26. The median age was 65 years (range 33-80). The median follow-up was 17.0 months (range 0.7-92.4). 5-year overall survival (OS) rates were 82% in patients with early-stage tumours and 23% in patients with later-stage tumours, respectively. Median OS was 89.9 months and 27.6 months, respectively (HR 0.25 (95% CI 0.08-0.84), P = 0.024). CONCLUSIONS: In an experienced European centre, 5-year survival rates after liver resection for early-stage hilar cholangiocarcinoma are comparable with reported outcomes after transplantation. The results of this study question the value of liver transplantation in this setting, especially with respect to the shortage of transplantable organs worldwide.

Changing outlook for colorectal liver metastasis resection in the elderly.

BACKGROUND: This study sought to evaluate the impact of the advancements in clinical care, obtained over the last 20 years, for patients aged 70 and older undergoing liver resection for colorectal liver metastases (CRLM). METHODS: Consecutive patients age 70 or older who underwent liver resection for CRLM at Aintree University Hospital (Liverpool, UK) between May 2008 and May 2015 were compared to a dataset of consecutive patients, meeting the same criteria, between 1990 and 2007. An enhanced recovery programme after surgery (ERAS) combined with cardiopulmonary exercise testing (CPET) was introduced in January 2008. RESULTS: The proportion of patients over 70 years undergoing liver resection for CRLM increased over the study period (6% in 1990, 16.3% in 2000, 26.5% in 2005 and 25.8% in 2007). The patients in the later group were more often treated with neoadjuvant chemotherapy (58 vs 34, p = 0.006) and underwent parenchymal sparing surgery, resulting in fewer major hepatectomies (51 vs 111, p < 0.001) and less perioperative morbidity (49 vs 70, p = 0.043) and mortality (3 vs 9, p = 0.229). Although there was shorter disease free survival (DFS) in the later group (DFS at 1, 3 and 5 years was 52.1%, 31.6%, 29% vs. 71.8%, 49.1%, 44.0%)(p < 0.01), similar overall survival (OS) was achieved (OS at 1, 3 and 5 years was 85.4%, 51.6%, 32.8% vs. 81.7%, 42.1%, 27.3%)(p = 0.21). CONCLUSIONS: This study demonstrates that, with modern management (ERAS, CPET, neoadjuvant chemotherapy and parenchymal sparing surgery), a greater number of patients with CRLM, over the age of seventy, can undergo liver resection, with improved perioperative outcomes.

Role of a pre-operative radiological scoring system in determining resectability for potentially resectable hilar cholangiocarcinoma.

AIMS: Cholangiocarcinoma is a rare cancer arising from the biliary tree. Case series indicate that 25-40% of all borderline resectable primary tumours are potentially resectable. The Memorial Sloane Kettering System (MSKCC) stratifies patients for resectability by longitudinal and radial extension of the hilar tumour. The Bismuth-Corlette system describes the longitudinal extension of the tumour within the biliary duct system. We sought to validate and, if possible, augment these two scores within an independent validation cohort. METHODS: Patients diagnosed with hilar cholangiocarcinoma between January 2009 and December 2016 were analysed from a prospectively held database. Patients with distal cholangiocarcinoma, peripheral cholangiocarcinoma and gallbladder cancer were excluded. Comparison of surgical findings to pre-operative radiological imaging was undertaken at the time of surgery. RESULTS: The validation cohort was formed of 198 patients, of which, 55 (27.8%) patients underwent resection. Logistic regression analyses identified that BC score, MSKCC score, age at diagnosis and left artery involvement were all significant independent predictor's univariately. BC score explained 28% of the variability in resectability compared to 26% explained by MSKCC. In combination, the model consisting of BC score, age at diagnosis and left artery involvement explained 39% of variability in resectability compared to the 34% explained same model including MSKCC score instead of BC score. CONCLUSION: In this cohort an augmented BC score, incorporating left hepatic artery involvement, is more discriminative in predicting resectability than the current MSKCC system.

Optimal perioperative care in peri-hilar cholangiocarcinoma resection.

Surgical resection remains the only proven curative treatment for peri-hilar cholangiocarcinoma. Despite recent advances in liver surgery techniques and perioperative care, resection for peri-hilar cholangiocarcinoma remains associated with significant morbidity and mortality. Considerable variation in the perioperative management of these patients exists. Optimal perioperative management has the potential to deliver improved outcomes. This article seeks to summarize the evidence underpinning best practice in the perioperative care of patients undergoing resection of peri-hilar cholangiocarcinoma. The authors also seek to identify areas where research efforts and future clinical trials should be targeted.

Oncosurgical Management of Liver Limited Stage IV Colorectal Cancer: Preliminary Data and Protocol for a Randomized Controlled Trial.

BACKGROUND: Colorectal cancer is the fourth commonest cancer and second commonest cause of cancer-related death in the United Kingdom. Almost 15% of patients have metastases on presentation. An increasing number of surgical strategies and better neoadjuvant treatment options are responsible for more patients undergoing resection of liver metastases, with prolonged survival in a select group of patients who present with synchronous disease. It is clear that the optimal strategy for the management of these patients remains unclear, and there is certainly a complete absence of Level 1 evidence in the literature. OBJECTIVE: The objective of this study is to undertake preliminary work and devise an outline trial protocol to inform the future development of clinical studies to investigate the management of patients with liver limited stage IV colorectal cancer. METHODS: We have undertaken some preliminary work and begun the process of designing a randomized controlled trial and present a draft trial protocol here. RESULTS: This study is at the protocol development stage only, and as such no results are available. There is no funding in place for this study, and no anticipated start date. CONCLUSIONS: We have presented preliminary work and an outline trial protocol which we anticipate will inform the future development of clinical studies to investigate the management of patients with liver limited stage IV colorectal cancer. We do not believe that the trial we have designed will answer the most significant clinical questions, nor that it is feasible to be delivered within the United Kingdom's National Health Service at this current time.

The impact of primary tumour location in patients undergoing hepatic resection for colorectal liver metastasis.

BACKGROUND: Primary tumour location has long been debated as a prognostic factor in colorectal cancer patients with liver metastases (CRLM) undergoing liver resection. This retrospective study was conducted to clarify the prognostic value of tumour location after radical hepatectomy for CRLM and its underlying causes. METHODS: We retrospectively analysed clinical data from 420 patients with CRLM whom underwent liver resection between January 2002 and December 2015. Right-sided (RS) tumours include tumours located in the cecum, ascending colon, and transverse colon, and left-sided (LS) tumours include those located in the splenic flexure, descending colon, sigmoid colon, and rectum. RESULTS: Both overall survival (OS) and disease-free survival (DFS) were similar between patients with RS and LS primary tumours (5-year OS: 46.5% vs 38.3%, P = 0.699; 5-year DFS: 29.1% vs 22.4%, P = 0.536). Specifically, RAS mutation rate was significantly higher in patients with RS tumours (P = 0.007). Subgroup analysis showed that the RAS mutation on the LS and RS tumours have different prognostic impact for CRLM patients on long-term survival after hepatic resection (RS, OS: P = 0.437, DFS: P = 0.471; LS, OS: P < 0.001, DFS: P = 0.002). The multivariable analysis showed that RAS mutant is an independent factor influencing OS in patients with LS primary tumour only. CONCLUSIONS: The site of the primary tumour has no significant impact on the long-term survival in patients with CRLM undergoing radical surgery. However, prognostic value of RAS status differs depending on the site of the primary tumour.

Hepatectomy for octogenarians with colorectal liver metastasis in the era of enhanced recovery.

BACKGROUND: Concern exists regarding the use of hepatectomy to treat colorectal liver metastasis (CRLM) in octogenarians due to prior studies suggesting elevated morbidity and mortality. Cardiopulmonary exercise testing (CPET) within pre-operative assessment and enhanced recovery after surgery (ERAS) have both been shown to be associated with low morbidity and mortality in patients undergoing hepatectomy. This study sought to compare the outcomes of octogenarians with patients aged 70-79 undergoing hepatectomy for CRLM, within a center utilizing both CPET and ERAS. METHODS: Consecutive patients age 70 or older who underwent hepatectomy for CRLM at Aintree University Hospital (Liverpool,UK), between May 2008 and May 2015 were identified from a prospectively maintained cancer database. Data were extracted and comparisons drawn. RESULTS: 127 patients aged 70-79 years and 34 octogenarians underwent respectively 137 and 35 hepatectomy for CRLM. There was no difference in hospital stay (6 days), morbidity and mortality between the groups. OS at 1, 3 and 5 years were 86.7%, 55% and 35.8% for those aged 70-79 compared to 79.4%, 37.3% and 20.4% for the octogenarians (p=0.127). DFS at 1,3 and 5 years was 52.5%, 31.7% and 31.7% for 70-79 group compared to 46.2%, 31.5% and 16.8% for the octogenarians (p=0.838). On multivariate analysis major hepatectomy was associated with an increased risk of post-operative complications, inferior OS and DFS. Chronological age was not a predictor of postoperative complications, poorer OS or DFS. CONCLUSIONS: Appropriately selected octogenarians can have similar postoperative outcomes to patients aged 70-79 when undergoing hepatectomy for CRLM using ERAS combined with CPET. This study advocates using CPET and ERAS in the selection and management of octogenarian patients with CRLM undergoing hepatectomy.

A modified TNM staging system for non-metastatic colorectal cancer based on nomogram analysis of SEER database.

BACKGROUND: To revise the American Joint Committee on Cancer TNM staging system for colorectal cancer (CRC) based on a nomogram analysis of Surveillance, Epidemiology, and End Results (SEER) database, and to prove the rationality of enhancing T stage's weighting in our previously proposed T-plus staging system. METHODS: Total 115,377 non-metastatic CRC patients from SEER were randomly grouped as training and testing set by ratio 1:1. The Nomo-staging system was established via three nomograms based on 1-year, 2-year and 3-year disease specific survival (DSS) Logistic regression analysis of the training set. The predictive value of Nomo-staging system for the testing set was evaluated by concordance index (c-index), likelihood ratio (L.R.) and Akaike information criteria (AIC) for 1-year, 2-year, 3-year overall survival (OS) and DSS. Kaplan-Meier survival curve was used to valuate discrimination and gradient monotonicity. And an external validation was performed on database from the Second Affiliated Hospital of Zhejiang University (SAHZU). RESULTS: Patients with T1-2 N1 and T1N2a were classified into stage II while T4 N0 patients were classified into stage III in Nomo-staging system. Kaplan-Meier survival curves of OS and DSS in testing set showed Nomo-staging system performed better in discrimination and gradient monotonicity, and the external validation in SAHZU database also showed distinctly better discrimination. The Nomo-staging system showed higher value in L.R. and c-index, and lower value in AIC when predicting OS and DSS in testing set. CONCLUSION: The Nomo-staging system showed better performance in prognosis prediction and the weight of lymph nodes status in prognosis prediction should be cautiously reconsidered.