The evaluation of metastatic lymph node ratio staging system in gastric cancer

Prognostic performance of examined lymph nodes, lymph node ratio, and positive lymph nodes in gastric cancer: a competing risk model study

Background

Previous research on the prognostic effectiveness of examined lymph nodes (ELN), lymph node ratio (LNR), and positive lymph nodes (pN) in postoperative gastric cancer (GC) has yielded inconsistent results despite their widespread use.

Methods

This study used a competing risk model (CRM) to evaluate the prognostic efficacy of these markers in patients with GC. Data from 337 patients with lymph node (LN)-positive stage II GC undergoing resection and chemotherapy between 2010 and 2015 were collected from the Surveillance, Epidemiology, and End Results database. Optimal cutoff values for ELN and LNR were determined using restricted cubic splines, and pN was divided into three groups based on the AJCC staging system. The survival analyses were conducted using Kaplan-Meier curves, Cox proportional hazards analysis, cumulative incidence curves, and CRM. Subgroup analysis and interaction tests were performed to evaluate the correlation between LN status and survival within subgroups.

Results

The results indicated that the optimal cutoff values for ELN, LNR, and pN were 16, 0.1, and 2. Multivariate Cox analysis showed that ELN (hazard ratio [HR] = 0.67), LNR (HR = 2.23), and pN (HR = 2.80) were independent predictors of overall survival, whereas only LNR (HR = 2.08) was independently associated with disease-specific survival. The CRM revealed that LNR (sub-distribution hazard ratio [SHR] = 1.89) and pN (SHR = 2.80) were independently associated with disease-specific survival.

Conclusion

In conclusion, ELN, LNR, and pN are all significant predictors of overall survival for GC. However, LNR demonstrates stronger robustness in predicting DSS than ELN and pN. The LNR may supplement the TNM staging system in identifying prognostic discrepancies.

A 9‑gene expression signature to predict stage development in resectable stomach adenocarcinoma

BACKGROUND

Stomach adenocarcinoma (STAD) is a highly heterogeneous disease and is among the leading causes of cancer-related death worldwide. At present, TNM stage remains the most effective prognostic factor for STAD. Exploring the changes in gene expression levels associated with TNM stage development may help oncologists to better understand the commonalities in the progression of STAD and may provide a new way of identifying early-stage STAD so that optimal treatment approaches can be provided.

METHODS

The RNA profile retrieving strategy was utilized and RNA expression profiling was performed using two large STAD microarray databases (GSE62254, n = 300; GSE15459, n = 192) from the Gene Expression Omnibus (GEO) and the RNA-seq database within the Cancer Genome Atlas (TCGA, n = 375). All sample expression information was obtained from STAD tissues after radical resection. After excluding data with insufficient staging information and lymph node number, samples were grouped into earlier-stage and later-stage. Samples in GSE62254 were randomly divided into a training group (n = 172) and a validation group (n = 86). Differentially expressed genes (DEGs) were selected based on the expression of mRNAs in the training group and the TCGA group (n = 156), and hub genes were further screened by least absolute shrinkage and selection operator (LASSO) logistic regression. Receiver operating characteristic (ROC) curves were used to evaluate the performance of the hub genes in distinguishing STAD stage in the validation group and the GSE15459 dataset. Univariate and multivariate Cox regressions were performed sequentially.

RESULTS

22 DEGs were commonly upregulated (n = 19) or downregulated (n = 3) in the training and TCGA datasets. Nine genes, including MYOCD, GHRL, SCRG1, TYRP1, LYPD6B, THBS4, TNFRSF17, SERPINB2, and NEBL were identified as hub genes by LASSO-logistic regression. The model achieved discrimination in the validation group (AUC = 0.704), training-validation group (AUC = 0.743), and GSE15459 dataset (AUC = 0.658), respectively. Gene Set Enrichment Analysis (GSEA) was used to identify the potential stage-development pathways, including the PI3K-Akt and Calcium signaling pathways. Univariate Cox regression indicated that the nine-gene score was a significant risk factor for overall survival (HR = 1.28, 95% CI 1.08-1.50, P = 0.003). In the multivariate Cox regression, only SCRG1 was an independent prognostic predictor of overall survival after backward stepwise elimination (HR = 1.21, 95% CI 1.11-1.32, P < 0.001).

CONCLUSION

Through a series of bioinformatics and validation processes, a nine-gene signature that can distinguish STAD stage was identified. This gene signature has potential clinical application and may provide a novel approach to understanding the progression of STAD.

Prognostic Nomogram for Early Gastric Cancer After Surgery to Assist Decision-Making for Treatment With Adjuvant Chemotherapy

Background: Most patients with early gastric cancer (EGC) can achieve a better 5-year survival rate after endoscopic resection or surgery. However, indications for adjuvant chemotherapy (ACT) after surgery have not yet been determined.

Methods: A total of 4,108 patients with EGC diagnosed in 2004–2016 were retrospectively analyzed using the Surveillance, Epidemiology, and End Results (SEER) database. Of these, 3,521 patients received postoperative ACT and 587 patients did not. Propensity score matching was used to balance the two groups’ confounding factors. Kaplan-Meier method was utilized to perform survival analysis. Log-rank test was used to compare the differences between survival curves. Cox proportional-hazards regression model was used to screen independent risk factors and build a nomogram for the non-ACT group. The X-tile software was employed to artificially divide all patients into low-, moderate-, and high-risk groups according to the overall survival score prediction based on the nomogram. A total of 493 patients with EGC diagnosed between 2010 and 2014 in our hospital were included for external validation.

Results: Multivariate analysis found that age, sex, race, marital status, primary site, surgical extent, and metastatic lymph node ratio in the non-ACT group were independent prognostic factors for EGC and were included in the construction of the nomogram. The model C-index was 0.730 (95% confidence interval: 0.677–0.783). The patients were divided into three different risk groups based on the nomogram prediction score. Patients in the low-risk group did not benefit from ACT, while patients in the moderate- and high-risk groups did. External validation also demonstrated that moderate- and high-risk patients benefited from ACT.

Conclusion: The study nomogram can effectively evaluate postoperative prognosis of patients with EGC. Postoperative ACT is therefore recommended for moderate- and high-risk patients, but not for low-risk patients.

A Prognostic Nomogram for T3N0 Rectal Cancer After Total Mesorectal Excision to Help Select Patients for Adjuvant Therapy

Background

The recurrence rate of T3N0 rectal cancer after total mesorectal excision (TME) is relatively low, meaning that not all patients need adjuvant therapy (AT) (radiotherapy, chemotherapy, or chemoradiotherapy).

Methods

Patients diagnosed with pT3N0M0 rectal cancer after TME were analyzed using the SEER database, of which 4367 did not receive AT and 2794 received AT. Propensity score matching was used to balance the two groups in terms of confounding factors. Cox proportional hazards regression analysis was used to screen independent prognostic factors, which were then used to establish a nomogram. The patients were then divided into three groups with X-tile software according to their risk scores. We enrolled 334 patients as external validation.

Results

The C-index of the model was 0.725 (95% confidence interval: 0.694–0.756). We divided the patients into three different risk layers based on the nomogram prediction scores, and found that AT did not improve the prognosis of low- and moderate-risk patients, while high-risk patients benefited from AT. External validation data also support the above conclusions.

Conclusion

This study developed a nomogram that effectively and comprehensively evaluates the prognosis of T3N0 rectal cancer patients after TME. After using the nomogram, we recommend AT for high-risk patients, but not for low- and moderate-risk patients.

Lymph node ratio-based the ypTNrM staging system for gastric cancer after neoadjuvant therapy: a large population-based study

PURPOSES

The lymph node ratio (LNR) has been considered a better prognostic factor than traditional N staging in patients with gastric cancer (GC), but its accuracy is unclear for those who receive neoadjuvant therapy (NAT). We aimed to compare the node ratio (Nr) staging with the ypN staging and to thereby develop a modified staging system incorporating Nr staging.

METHODS

A total of 1791 patients who underwent gastrectomy after NAT in the Surveillance, Epidemiology, and End Results database were retrospectively analyzed. ypTNrM staging was established based on the overall survival (OS).

RESULTS

The Nr staging was generated using 0.2 and 0.5 as the cutoff values of LNR and represented patients with more homogeneous OS compared with ypN staging. The 5-year OS rates for ypTNrM stages IA, IB, II, IIIA, and IIIB were 70.2%, 54.2%, 36.0%, 21.2%, and 6.6%, respectively, compared with 58.8%, 39.1%, and 21.6% for ypTNM stages I, II, and III, respectively. Compared with the ypTNM staging system, the ypTNrM staging system had a lower misclassification rate (3.0% vs. 50.9%) and better prognostic predictive power (C-index: 0.645 vs. 0.589, P < 0.001).

CONCLUSIONS

The ypTNrM staging system incorporating Nr staging may provide a more accurate assessment in the clinical decision-making process for GC after NAT.

Towards standardization of lymph-node ratio classifications: Validation and comparison of different lymph node ratio classifications for predicting prognosis of patients with resected gastric cancer

INTRODUCTION

The TNM staging system is the main prognostic tool for GC, but the number of metastatic lymph nodes (LN) can be affected by surgical, pathological, tumor or host factors. Several authors have shown that lymph node ratio (LNR) may be superior to TNM staging in GC. However, cut-off values vary between studies and LNR assessment is not standardized.

MATERIAL AND METHODS

Retrospective study of all GC resected in a western tertiary center (N = 377). Clinical features were collected and pathological features were assessed by two independent pathologists. Eight LNR classifications were selected and applied to our patients. Statistical analyses were performed.

RESULTS

315 patients were included. Most tumors were T3 (49.2%) N+ (59.3%). During follow-up, 36.7% of patients progressed and 27.4% died due to tumor. All LNR classifications were significantly associated with clinicopathological features such as Laurén subtype, lymphovascular invasion, perineural infiltration, T stage, tumor progression or death. All LNR classifications were independent prognostic factors for OS and DFS, and ROC analyses calculated similar AUC values for all staging systems. Kaplan-Meier curves showed that Pedrazzani, Wang, Liu and Huang classifications stratified patients better into three (Pedrazzani) or four categories. These classifications tended to downstage TNM N2 and N3 tumors. In cases with less than 16 LNs resected, Pedrazzani and Wang classifications showed the best prognostic performance.

CONCLUSIONS

Pedrazzani, Wang, Liu and Huang classifications showed good prognostic performance in western GC patients. Larger studies in other cohorts are needed to identify the most consistent LNR classification for GC.

The Prognostic Value of Postoperative Lymph Node Ratio in Gastric Adenocarcinoma Patients Treated With Neoadjuvant Chemotherapy

Objective

In this study, we aimed to investigate the prognostic value of postoperative lymph node ratio (LNR)in locally advanced gastric cancer (GC) patients receiving neoadjuvant chemotherapy (NACT).

Methods

LNR was calculated as the ratio of positive LNs to the total LNs removed. The receiver operating characteristic (ROC) curve was plotted to estimate the cut-off value of LNR for recurrence. The area under the curve of LNR was 0.714 (95% CI: 0.604-0.825, p<0.001) with 60% sensitivity and >0.255 with 76% specificity. Patients were grouped as group I (≤0.255) and group II (>0.255).

Results

In this study, 157 GC patients were included (39.5% female and 60.5% male). Of the patients, 97 (61.8%) were in group I and 60 (38.2%) were in group II. Disease‑free survival (DFS) was not reached in group I, and it was 16 months in group II (p<0.001). Overall survival (OS) was 58 months in group I and 28 months in group II (p>0.001). In multivariate analysis, lymphovascular invasion, neoadjuvant response, adjuvant treatment, and LNR were found to be the factors associated with DFS and OS (p<0.05).

Conclusion

In our study, it was observed that LNR can predict survival rates better than LN staging.

Impact of the 8th edition of the AJCC TNM classification on gastric cancer prognosis-study of a western cohort

Introduction

The 8th edition of the American Joint Committee on Cancer (AJCC) TNM classification for gastric cancer introduced changes, mainly in stage III, with the incorporation of the pN3 sub-classification in the final staging group. The goal was to compare the 7th and 8th editions to evaluate the discriminative capacity of the new edition.

Methods

This study was a retrospective review of patients with gastric cancer treated with surgery in 2013 and 2014.

Results

We analysed 310 patients, with a median age of 66 years and out of which 55.5% were male. The most commonly performed surgery was subtotal gastrectomy (n = 158; 51%), with a median of 30 lymph nodes removed. With a median follow-up of 39.5 months, the 1- and 3-year overall survival (OS) was 82% and 59%, respectively. In stage III (n = 115), there was stage migration in 40 cases (34.8%), with upstage in 11 cases and downstage in 29 cases. In this group, there was a statistically significant difference in OS between N3a and N3b patients (p = 0.002), as well as a statistically significant difference in OS between stages IIIA, IIIB and IIIC when the 8th edition was applied (p = 0.001), which was not verified with the 7th edition (p = 0.057). In multivariate analysis, both extracapsular extension and N classification from TNM were independent prognostic factors (p = 0.033 and p = 0.024, respectively).

Conclusion

The 8th edition of the AJCC TNM classification allows for a better prognostic refinement, namely in the new stage III groups after the stratification of lymph node disease in N3a and N3b. Factors that evaluate the biological behaviour of the disease remain excluded from this edition, such as extracapsular extension, which had a prognostic impact in our series.

The assessment of the optimal number of examined lymph nodes and prognostic models based on lymph nodes for predicting survival outcome in patients with stage N3b gastric cancer

BACKGROUND

The optimal number of examined lymph nodes (ELNs) and the prognostic value of different nodal staging systems remain unclear in the context of N3b gastric cancer.

AIM

To evaluate the optimal number of ELNs and compare the predictive ability of the ELN number, LN ratio (LNR), and log odds of metastatic LNs (LODDS) for overall survival (OS) in patients with resected stage N3b gastric adenocarcinoma in an international database.

METHODS

A total of 868 patients diagnosed between 2004 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database (training cohort) and 144 patients diagnosed between 2011 and 2016 at the Liaoning Cancer Hospital (validation cohort) were identified. Cutoff values were established with X-tile. The 5-year OS rates were compared using Kaplan-Meier curves. Multivariate analysis was conducted with a Cox regression model. The Harrell's concordance index and Akaike's information criterion were used to compare the predictive accuracy of different nodal staging systems.

RESULTS

The ELN number, LNR, and LODDS were independent prognostic factors for both the training and validation cohorts in the multivariate analysis. Patient with ≤26 ELNs, LNR of more than 0.9, and LODDS of more than 1.0 were associated with decrease OS. The LNR and LODDS had similar discriminatory ability for OS and performed better than the ELN number in the Eastern and Western populations.

CONCLUSION

The optimal number of ELN may be 27 or more because LNs retrieved ≤26 was an independent risk factor for the prognosis. The prognostic prediction efficacy of LNR and LODDS was similar and better than that of ELN. Thus, LNR and LODDS could both serve as valid tools to predict OS for stage N3b patients.

A Novel Staging System to Forecast the Cancer-Specific Survival of Patients With Resected Gallbladder Cancer

Objective: Gallbladder cancer (GBC) is one of the most aggressive malignant tumors, and there is no effective and convenient method for predicting cancer-specific survival (CSS). We aim to develop a novel nomogram staging system based on the positive lymph node ratio (pLNR) for GBC patients.

Methods:A total of 1,356 patients enrolled in the study. We evaluated the prognostic value of the pLNR and built a prognostic nomogram staging system based on the pLNR in the training cohort. The concordance index and calibration plots were used to evaluate model discrimination. The predictive accuracy and clinical value of the nomograms were measured by decision curve analysis (DCA). The CSS nomogram was further validated in an internal validation cohort.

Results:The pLNR was an independent prognostic factor for CSS based on Cox regression analyses. A prognostic nomogram that combined T classification, pLNR, M classification, histologic grade, live metastasis, and tumor size was formulated with a c-index of 0.763 (95% CI, 0.728–0.798), while the c-indexes for the staging system of AJCC 8th, 7th, and 6th for CSS prediction were 0.718, 0.718, and 0.717, respectively. The calibration curves showed perfect agreement. The DCA showed that the nomogram provided substantial clinical value. The nomogram (the AUCs for 1, 3, and 5 years were 0.693, 0.716, and 0.726, respectively,) showed high prognostic accuracy.

Conclusion:We have developed a formulated nomogram staging system based on the pLNR that allows more accurate individualized predictions of CSS for resected GBC patients than the AJCC staging systems.

Prognostic value of lymph node ratio in laryngeal and hypopharyngeal squamous cell carcinoma: a systematic review and meta-analysis

Background

Several recent studies have indicated that the lymph node ratio (LNR) is an independent prognostic factor for laryngeal and hypopharyngeal squamous cell carcinoma (LHSCC). The purpose of this paper is to assess the prognostic value of LNR and explore appropriate cutoff values by conducting a systematic review and meta-analysis.

Methods

Pubmed, Embase (via Ovid), and Cochrane library were systematically searched for studies on the prognostic value of LNR in LHSCC up to October 31, 2019. Then, Literature review, data extraction, and quality assessment of eligible studies were performed by two independent reviewers back-to-back. Lastly, Stata 14.0 software was hired to conduct a meta-analysis.

Results

A total of 445 articles were retrieved, and 13 studies published in English between 2013 and 2019 were included after the title/abstract and full-text screening. Among the 13 studies contributed to 4197 patients, seven studies were about hypopharyngeal squamous cell carcinoma (HPSCC), four studies about laryngeal squamous cell carcinoma (LSCC), and the remaining two studies about LHSCC. The meta-analysis results showed that shorter overall survival (OS) (HR 1.49; 95%CI: 1.18 to 1.88), disease-specific survival (DSS) (HR 1.66; 95%CI: 1.32 to 2.07) and disease-free survival (DFS) (HR 2.04; 95%CI: 1.54 to 2.71) were significantly correlated with a higher LNR in a random-effect model. The cutoff values of eligible studies were varied from 0.03 to 0.14, and the lowest significant LNR was 0.044.

Conclusion

LNR is a valuable prognostic factor in the survival of LHSCC and may be used to improve the tumor staging systems, which, however, requires the solid support of more high-quality studies.

The Role of the Lymph Node Ratio in Advanced Gastric Cancer After Neoadjuvant Chemotherapy

The ratio of positive lymph nodes (LNs) to the total LN harvest is called the LN ratio (LNR). It is an independent prognostic factor in gastric cancer (GC). The aim of the current study was to evaluate the impact of neoadjuvant chemotherapy (NAC) on the LNR (ypLNR) in patients with advanced GC. We retrospectively analyzed the data of patients with advanced GC, who underwent gastrectomy with N1 and N2 (D2) lymphadenectomy between August 2011 and January 2019 in the Department of Surgical Oncology at the Medical University of Lublin. The exclusion criteria were a lack of preoperative NAC administration, suboptimal lymphadenectomy (<D2 and/or removal of less than 15 lymph nodes), and a lack of data on tumor regression grading (TRG) in the final pathological report. A total of 95 patients were eligible for the analysis. A positive correlation was found between the ypLNR and tumor diameter (p < 0.001), post treatment pathological Tumour (ypT) stage (p < 0.001), Laurén histological subtype (p = 0.0001), and the response to NAC (p < 0.0001). A multivariate analysis demonstrated that the ypLNR was an independent prognostic factor in patients with intestinal type GC (p = 0.0465) and in patients with no response to NAC (p = 0.0483). In the resection specimen, tumor diameter and depth of infiltration, Laurén histological subtype, and TRG may reflect the impact of NAC on LN status, as quantified by ypLNR in advanced GC.

Evaluation of Lymph Node Ratio Association With Long-term Patient Survival After Surgery for Node-Positive Merkel Cell Carcinoma

Importance

Merkel cell carcinoma (MCC) carries the highest mortality rate among cutaneous cancers and is rapidly rising in incidence. Identification of prognostic indicators may help guide patient counseling and treatment planning. Lymph node ratio (LNR), the ratio of positive lymph nodes to the total number of examined lymph nodes, is an established prognostic indicator in other cancers.

Objectives

The primary objective was to evaluate the association between LNR and patient survival after surgery for node-positive MCC. The secondary objective was to evaluate whether the survival rates associated with adjuvant therapies vary by patient LNR status.

Design, Setting, and Participants

Retrospective cohort study of patients with node-positive MCC treated with surgery and lymphadenectomy. We queried the National Cancer Database (NCDB) and the Surveillance, Epidemiology, and End Results (SEER) registry for patient records. Data originated from 2004 through 2017 for the NCDB and from 1973 through 2016 for the SEER registry. The SEER registry comprises a population-based US cohort while cases from the NCDB include all reportable cases from Commission on Cancer-accredited facilities and represents approximately 70% of all newly diagnosed cancers in the United States. All data analysis took place between August 1, 2018, and February 11, 2019.

Exposures

The ratio of positive lymph nodes to the total number of examined lymph nodes, LNR, was stratified into quartiles.

Main Outcomes and Measures

Overall survival (NCDB) and disease-specific survival (SEER).

Results

We identified 736 eligible cases in the NCDB and 538 eligible cases in the SEER registry. Among these 1274 patients, the mean (SD) age was 71.1 (11.5) years, and 401 (31.5%) were women. After controlling for clinical and tumor factors including AJCC N staging, patient LNR of 0.07 to 0.31 (hazard ratio [HR], 1.37; 95% CI, 1.03-1.81) and greater than 0.31 (HR, 2.84; 95% CI, 2.10-3.86) was associated with significantly worse survival than an LNR less than 0.07. Univariate supplementary analysis performed in the SEER data set revealed a similar association of LNR with disease-specific survival. For patients with an LNR greater than 0.31, treatment with surgery and adjuvant chemoradiation therapy was associated with improved survival compared with surgery and adjuvant radiation therapy alone (HR, 0.61; 95% CI, 0.38-0.97), while this was not found for patients with an LNR of 0.31 or lower (HR, 0.93; 95% CI, 0.65-1.33).

Conclusions and Relevance

For lymph node-positive MCC, LNR offers a potentially prognostic metric alongside traditional TNM staging that may be useful for both patient counseling and treatment planning after surgery.

A homogenized approach to classify advanced gastric cancer patients with limited and adequate number of pathologically examined lymph nodes

Background

The prognosis of gastric cancer patients with a limited number of pathologically examined lymph nodes (eLN, < 16) is dismal compared to those with adequately eLN (≥ 16), yet they are still classified within the same subgroups using the American Joint Committee on Cancer (AJCC) staging system. We aimed at formulating an easy-to-adopt and clinically reliable stratification approach to homogenize the classification for these two categories of patients.

Methods

Patients staged according to the 8th AJCC pathological nodal (N) and tumor-node-metastasis (TNM) classification were stratified into a Limited and Adequate eLN cohort based on their number of pathologically examined LNs. The statistical differences between the 5-year overall survival (OS) rates of both cohorts were determined and based on which, patients from the Limited eLN cohort were re-classified to a proposed modified nodal (N′) and TNM (TN′M) classification, by matching their survival rates with those of the Adequate eLN cohort. The prognostic performance of the N′ and TN′M classification was then compared to a formulated lymph-node-ratio-based nodal classification, in addition to the 8th AJCC N and TNM classification.

Results

Significant heterogeneous differences in 5-year OS between patients from the Limited and Adequate eLN cohort of the same nodal subgroups were identified (all P < 0.001). However, no significant differences in 5-year OS were observed between the subgroups N0, N1, N2, and N3a of the Limited eLN cohort when compared with N1, N2, N3a, and N3b from the Adequate eLN cohort, respectively (P = 0.853, 0.476, 0.114, and 0.230, respectively). A novel approach was formulated in which only patients from the Limited eLN cohort were re-classified to one higher nodal subgroup, denoted as the N′ classification. This re-classification demonstrated superior stratifying and prognostic ability as compared to the 8th AJCC N and lymph-node-ratio classification (Akaike information criterion values [AIC]: 12,276 vs. 12,358 vs. 12,283, respectively). The TN′M classification also demonstrated superior prognostic ability as compared to the 8th AJCC TNM classification (AIC value: 12,252 vs. 12,312).

Conclusion

The proposed lymph node classification approach provides a clinically practical and reliable technique to homogeneously classify cohorts of gastric cancer patients with limited and adequate number of pathologically examined lymph nodes.

Defining the Role of Lymphadenectomy for Pancreatic Neuroendocrine Tumors: An Eight-Institution Study of 695 Patients from the US Neuroendocrine Tumor Study Group

BACKGROUND

Preoperative factors that reliably predict lymph node (LN) metastases in pancreatic neuroendocrine tumors (PanNETs) are unclear. The number of LNs needed to accurately stage PanNETs has not been defined.

METHODS

Patients who underwent curative-intent resection of non-functional PanNETs at eight institutions from 2000 to 2016 were analyzed. Preoperative factors associated with LN metastases were identified. A procedure-specific target for LN retrieval to accurately stage patients was determined.

RESULTS

Of 695 patients who underwent resection, 33% of tumors were proximal (head/uncinate) and 67% were distal (neck/body/tail). Twenty-six percent of patients (n = 158) had LN-positive disease, which was associated with a worse 5-year recurrence-free survival (RFS; 60% vs. 86%; p < 0.001). The increasing number of positive LNs was not associated with worse RFS. Preoperative factors associated with positive LNs included tumor size ≥ 2 cm (odds ratio [OR] 6.6; p < 0.001), proximal location (OR 2.5; p < 0.001), moderate versus well-differentiation (OR 2.1; p = 0.006), and Ki-67 ≥ 3% (OR 3.1; p < 0.001). LN metastases were also present in tumors without these risk factors: < 2 cm (9%), distal location (19%), well-differentiated (23%), and Ki-67 < 3% (16%). Median LN retrieval was 13 for pancreatoduodenectomy (PD), but only 9 for distal pancreatectomy (DP). Given that PD routinely includes a complete regional lymphadenectomy, a minimum number of LNs to accurately stage patients was not identified. However, for DP, removal of less than seven LNs failed to discriminate 5-year RFS between LN-positive and LN-negative patients (less than seven LNs: 72% vs. 83%, p = 0.198; seven or more LNs: 67% vs. 86%; p = 0.002).

CONCLUSIONS

Tumor size ≥ 2 cm, proximal location, moderate differentiation, and Ki-67 ≥ 3% are preoperative factors that predict LN positivity in resected non-functional PanNETs. Given the 9-23% incidence of LN metastases in patients without such risk factors, routine regional lymphadenectomy should be considered. PD inherently includes sufficient LN retrieval, while DP should aim to remove seven or more LNs for accurate staging.

Lymph Node Ratio: Is It an Independent Prognostic Factor for Stage III Cutaneous Melanoma?

Objective: Lymph node ratio (LNR) is defined as the ratio of the number of metastatic lymph nodes to the dissected lymph nodes. LNR is a prognostic factor for many tumor types. The present study aimed to evaluate the prognostic value of LNR in melanoma. Methods: This retrospective cohort study was conducted on 123 patients with stage III cutaneous melanoma. Multivariate Cox proportional hazards model was used to evaluate the correlations between LNR and other clinicopathological factors associated with survival. The patients were divided into four groups in terms of the LNR, including groups A (LNR≤0.18), B (0.180.625). Results: Initially, LNR was evaluated as a continuous quantity associated with survival. In the univariate analysis, a significant correlation was observed between LNR, overall survival (OS), and disease free survival (DFS). Meanwhile, the only association observed in the multivariate analysis was between LNR and OS. Increased LNR from group A to group D reduced OS from 46 (±44.09) to 22.5 (±16.33) months (P=0.022). According to the multivariate analysis, prognostic factors in OS were tumor thickness, American joint committee of cancer (AJCC) N stage, interferon administration, and undergoing chemotherapy. Conclusion: According to the results, LNR could be used as an independent prognostic factor for estimating the survival of patients with stage III cutaneous melanoma also designing an effective adjuvant treatment protocol for these patients.

The association of the lymph node ratio and serum carbohydrate antigen 19-9 with early recurrence after curative gastrectomy for gastric cancer

PURPOSE

This study investigated the predictors associated with early recurrence (i.e. within 12 months) after curative gastrectomy for gastric cancer (GC).

METHODS

We evaluated the clinicopathological factors in 429 patients who underwent curative gastrectomy for GC without preoperative chemotherapy and analyzed these factors' associations with early recurrence.

RESULTS

Of 429 patients, 57 experienced recurrences, which were associated with gender, diameter, depth of invasion, lymph node (LN) metastasis, the LN ratio (LNr; LNs with metastasis/dissected LNs), lymphatic invasion, vascular invasion, carbohydrate antigen 19-9 (CA19-9) levels, C-reactive protein levels and the neutrophil/lymphocyte ratio. Twenty-one patients (36.8%) recurred within 12 months. Early recurrence was associated with a high LNr (P = 0.0020) and high CA19-9 levels (P = 0.0415). The other factors were not significantly associated with early recurrence. The 12-month recurrence rate was 33.9% in patients with a high LNr and 1.9% in those with a low LNr and 20.3% in patients with high CA19-9 levels and 3.5% in those with low CA19-9 levels. The 12-month recurrence rate was 62.5% in patients with a high LNr and high CA19-9 levels, 18.4% in those with a high LNr or high-CA19-9 levels, and 1.4% in those with a low LNr and low CA19-9 levels.

CONCLUSION

LNr ≥ 0.15 and CA19-9 ≥ 37 U/ml were effective surrogate markers for predicting early recurrence.

The prognostic value of different node staging systems in patients with ≤15 lymph nodes following surgery for gastric adenocarcinoma

AIM

Lymph node (LN) status is an important prognostic indicator in patients with gastric cancer (GC). Although American Joint Committee on Cancer/International Union against Cancer (AJCC/UICC) is the most widely used staging system, there is a challenge in predicting survival of patients when the number of total harvested LNs is ≤15. Our aim was to investigate the prognostic performances of seventh edition AJCC/UICC, lymph-node ratio (LNR), and log odds of metastatic lymph nodes (LODDS) on the overall survival (OS) of GC patients with ≤15 examined LNs after gastric resection.

MATERIAL AND METHOD

A total of 74 patients who underwent curative resection for gastric adenocarcinoma and had ≤15 LNs at the final histopathological examination were included in the study. The prognostic ability of three node staging models to predict OS was assessed using the area under the curve (AUC).

RESULTS

Of the 74 patients, 15 (20.3%) had no LN metastasis whereas 59 (79.7%) had nodal involvement. The median OS was 26 months. When assessed as a continuous variable, LNR was the strongest staging system to stratify GC patients on the basis of LN status. LODDS had superiority on other node staging models when the number of LNs retrieved was modeled as categorical variable.

CONCLUSIONS

LNR (continuous) and LODDS (categorical) were the strongest indicators of OS in GC when the number of LN harvested was ≤15. Therefore, they may be considered as an alternative nodal staging systems for GC.

The effectiveness of the 8th American Joint Committee on Cancer TNM classification in the prognosis evaluation of gastric cancer patients: A comparative study between the 7th and 8th editions

BACKGROUND

The 8th edition of the AJCC TNM staging system for gastric cancer was released in 2016 and included major revisions, especially of stage III.

PATIENTS AND METHODS

Data from 3281 patients with GC who underwent R0 resection between December 2006 and November 2014 were reviewed. Of them, 1579 patients with stage III according to the seventh edition were analyzed and the 7th and 8th TNM classifications were compared.

RESULTS

The most important tumor stages change observed in stage III GC. For stage III patients, the median number of lymph nodes (LNs) resected in stage III patients was 33 (range 5-112), and the optimal cut-off value for the number of LNs resected was 30. Although the 7th edition classification had higher c-index, linear trend and likelihood ratio χ2 scores, and smaller AIC values compared with those for the 8th edition, which represented the optimum prognostic stratification, however, the differences between 7th and 8th edition seems to be not statistically significant, and AIC demonstrates similar trend as well. Further subgroup analysis found that the 8th staging system generated the marginally better prognostic stratification only when LNs removed ≥30.

CONCLUSION

The 8th TNM classification may provide better accuracy than 7th edition in predicting the prognosis of stage III GC after R0 resection with LNs harvested ≥30. However, further research in an external validation setting is warranted.

Comparison of different lymph node staging systems in prognosis of gastric cancer: a bi-institutional study from Hungary

OBJECTIVE

The Union for International Cancer Control (UICC) Node (N) classification is the most common used staging method for the prognosis of gastric cancer. It demands adequate, at least 16 lymph nodes (LNs) to be dissected; therefore different staging systems were invented.

METHODS

Between March 2005 and March 2010, 164 patients were evaluated at the Department of General Surgery in the Kenézy Gyula Hospital and at the Department of General, Thoracic and Vascular Surgery in the Kaposi Mór Hospital. The 6th, 7th and 8th UICC N-staging systems, the number of examined LNs, the number of harvested negative LNs, the metastatic lymph node ratio (MLR) and the log odds of positive LNs (LODDS) were determined to measure their 5-year survival rates and to compare them to each other.

RESULTS

The overall 5-year survival rate for all patients was 55.5% with a median overall survival time of 102 months. The tumor stage, gender, UICC N-stages, MLR and the LODDS were significant prognostic factors for the 5-year survival with univariate analysis. The 6th UICC N-stage did not follow the adequate risk in comparing N2 vs. N0 and N3 vs. N0 with multivariate investigation. Comparison of performances of the residual N classifications proved that the LODDS system was first in the prediction of prognosis during the evaluation of all patients and in cases with less than 16 harvested LNs. The MLR gave the best prognostic prediction when adequate (more than or equal to 16) lymphadenectomy was performed.

CONCLUSIONS

We suggest the application of LODDS system routinely in western patients and the usage of MLR classification in cases with extended lymphadenectomy.

Lymph Node Ratio-based Staging System Outperforms the Seventh AJCC System for Gastric Cancer: Validation Analysis With National Taiwan University Hospital Cancer Registry

BACKGROUND

On the basis of SEER data, in which most gastric cancer patients had limited lymph node dissection, node ratio-based staging system (TNrM) has been shown to have better accuracy than the AJCC TNM system. This study is to validate the result with patients from Taiwan, where D2 lymphadenectomy is routinely performed.

PATIENT AND METHOD

A total of 1405 consecutive gastric cancer patients treated at National Taiwan University Hospital between 1998 and 2010 were included. To evaluate the performance of the AJCC system, each TNM stage was stratified by TNrM stages. The homogeneity of patients' survival across TNrM strata was evaluated using the log-rank test. The performance of the TNrM system was evaluated with the same approach.

RESULTS

Five of the 7 evaluable AJCC stages (IA, IIA, IIIA, IIIB, and IIIC) contained TNrM subgroups with statistically heterogenous survival (P=0.003, 0.04, 0.002, 0.04, and <0.001, respectively). Thirty-six percent of patients (506/1405) were misclassified by the AJCC TNM system. However, of the assessable 6 TNrM stages, none of the AJCC subgroups showed significantly heterogenous survivals (P>0.05). About 19% of patients (264/1405) were misclassified by using the TNrM system.

CONCLUSIONS

Lymph node ratio significantly decreases the stage migration caused by inadequate examined lymph nodes. The advantage of TNrM was validated with a patient cohort from the Eastern medical center.

Clinicopathologic implication of meticulous pathologic examination of regional lymph nodes in gastric cancer patients

BACKGROUND

We aimed to investigate effect of increased number of examined lymph nodes (LNs) to pN category, and compare various N categories in gastric cancer: American Joint Committee on Cancer (AJCC) 7th edition, metastatic LN ratio (MLR), and log odds of positive LNs (LODDS).

METHODS

Four cohorts with a total of 2,309 gastric cancer patients were enrolled. For cohort 1 and 2, prognostic significance of each method by disease-specific survival was analyzed using Akaike and Bayesian information criterion (AIC and BIC).

RESULTS

The total LNs in four cohorts significantly differed [median (range), 28 (6-97) in cohort 1, 37 (8-120) in cohort 2, 48 (7-122) in cohort 3, and 54 (4-221) in cohort 4; p<0.001]. The numbers of negative LNs increased with increase of total LN (p<0.001), but the numbers of metastatic LNs did not increase from cohort 1 to 4. MLR and LODDS in four cohorts had decreasing tendency with increase of total LNs in each pT3 and pT4 category (p<0.001), while the numbers of metastatic LNs did not differ significantly in any pT category (p>0.05). The AIC and BIC varied according to different cut-off values for MLR; model by cut-offs of 0.2 and 0.5 being better for cohort 1, while cut-offs 0.1 and 0.25 was better for cohort 2.

CONCLUSION

Our study showed that the number of metastatic LNs did not increase with maximal pathologic examination of regional LNs. AJCC 7th system is suggested as the simplest method with single cut-off value, but prognostic significance of MLR may be influenced by various cut-offs.

N staging system: tumor-node-metastasis and future perspectives

The correct staging of disease, with an exact definition of the extent of cancer at the diagnosis, is crucial in the planning of a specific treatment and in the assessment of real chances of cure. Cancer staging systems are expected to be accurate in the description of the severity of a patient's tumor on the basis of the extent of the primary neoplasm and of its spread, thus giving clinician tools to estimate prognosis and providing objective parameters to compare groups of patients in clinical studies. This last point is of wide importance in evaluating successful treatment strategies in oncology, and this is one of the issues that contributed to the development of stage-adapted therapies.

Clinical significance of accurate identification of lymph node status in distant metastatic gastric cancer

PURPOSE

The clinical consequences of accurately identifying lymph node (LN) status in distant metastatic gastric cancer (DMGC) are unclear. We aimed to determine the prognostic significance of N stage, positive LN (PLN) count, and the positive LN ratio (LNR). We also retrospectively compared survival outcomes of DMGC patients stratified by LN dissection (LND).

RESULTS

LND was performed in 1593 patients. The CSS was significantly different between groups divided according to N stage, PLN, and LNR in DMGC patients who underwent LND. Lower LNR was an independent predictor of longer survival in all kinds of patients cohorts, whereas PLN was not such a predictor. PLN count correlated with LND number and LNR. No correlation existed between LNR and LND number. Undergoing LND and having a higher number of dissected LNs were associated with superior CSS.

MATERIALS AND METHODS

Data from 1889 DMGC patients treated between 2004 and 2009, and documented in the Surveillance, Epidemiology, and End Results (SEER) registry, were reviewed. Pearson's correlation coefficient and the Chi-square test were used to study the relationships between LND number, PLN count, N stage, and the LNR. Cancer-specific survival (CSS) was evaluated using Kaplan-Meier analysis, with the log-rank test performed for univariate analysis (UVA) and the Cox proportional hazards model employed for multivariate analysis (MVA).

CONCLUSION

LN metastatic variables play important roles in the prognostic evaluation and treatment decisions of DMGC patients. Accurate identification of LN status in DMGC patients is critical. LND performance is associated with increased survival and has clinical practicability.

Comparison of three lymph node classifications for survival prediction in distant metastatic gastric cancer

BACKGROUND

The optimal lymph node (LN) classification system for prognostic assessment in distant metastatic gastric cancer (DMGC) patients who undergo LN dissection remains unclear. Therefore, we compared the prognostic performance of positive LN (PLN), LN ratio (LNR), and log odds of positive LNs (LODDS) in DMGC patients.

METHODS

A total of 1999 DMGC patients who underwent lymphadenectomy recorded in the Surveillance Epidemiology and End Results database from 2004 to 2012 were reviewed.

RESULTS

Univariate analyses showed that the PLN, LNR and LODDS systems were all significantly correlated with cancer-specific survival (CSS). However, only the LODDS classification remained an independent prognostic factor through the multivariate analysis. Furthermore, this classification could efficiently discriminate survival outcomes in patients within the same positive PLN category, as well as in patients with no positive node involvement. Both the LODDS and LNR classifications had better discriminatory ability, monotonicity, and homogeneity of prognostic stratification, as well as more accurate 1 or 2-year CSS prediction, than the PLN classification. The performances of the LNR and LODDS classifications were similar. Additionally, we found that inclusion of PORT carried a survival benefit across all LODDS intervals except the "LODDS ≤ -1.0" subgroup.

CONCLUSION

Our findings indicate that the LODDS classification is the most optimal system for prognostic assessment in DMGC patients. Incorporating LODDS into the staging system of DMGC patients will enable clinicians to more accurately predict prognosis and guide regional therapy regimen decisions in DMGC patients.

Seventh tumor-node-metastasis staging of gastric cancer: Five-year follow-up

Seventh tumor-node-metastasis (TNM) classification for gastric cancer, published in 2010, introduced changes in all of its three parameters with the aim to increase its accuracy in prognostication. The aim of this review is to analyze the efficacy of these changes and their implication in clinical practice. We reviewed relevant Literature concerning staging systems in gastric cancer from 2010 up to March 2016. Adenocarcinoma of the esophago-gastric junction still remains a debated entity, due to its peculiar anatomical and histological situation: further improvement in its staging are required. Concerning distant metastases, positive peritoneal cytology has been adopted as a criterion to define metastatic disease: however, its search in clinical practice is still far from being routinely performed, as staging laparoscopy has not yet reached wide diffusion. Regarding definition of T and N: in the era of multimodal treatment these parameters should more influence both staging and surgery. The changes about T-staging suggested some modifications in clinical practice. Differently, many controversies on lymph node staging are still ongoing, with the proposal of alternative classification systems in order to minimize the extent of lymphadenectomy. The next TNM classification should take into account all of these aspects to improve its accuracy and the comparability of prognosis in patients from both Eastern and Western world.

Superiority of lymph node ratio-based staging system for prognostic prediction in 2575 patients with gastric cancer: validation analysis in a large single center

This study aimed to evaluate the prognostic significance of node ratio (Nr), the ratio of metastatic to retrieved lymph nodes, and to investigate whether a modified staging system based on Nr can improve prognostic ability for gastric cancer patients following gastrectomy. A total of 2572 patients were randomly divided into training set and validation set, and the cutoff points for Nr were produced using X-tile. The relationships between Nr and other clinicopathologic factors were analyzed, while survival prognostic discriminatory ability and accuracy were compared among different staging systems by AIC and C-index in R program. Patients were categorized into four groups as follows: Nr0, Nr1: 0.00-0.15, Nr2: 0.15-0.40 and Nr3: > 0.40. Nr was significantly associated with clinicopathologic factors including macroscopic type, tumor differentiation, lymphovascular invasion, perineural invasion, tumor size, T stage, N stage and TNM stage. Besides, for all patients, Nr and TNrM staging system showed a smaller AIC and a larger C-index than that of N and TNM staging system, respectively. Moreover, in subgroup analysis for patients with retrieved lymph nodes < 15, Nr was demonstrated to have a smaller AIC and a larger C-index than N staging system. Furthermore, in validation analysis, Nr, categorized by our cutoff points, showed a larger C-index and a smaller AIC value than those produced in previous studies. Nr could be considered as a reliable prognostic factor, even in patients with insufficient (< 15) retrieved lymph nodes, and TNrM staging system may improve the prognostic discriminatory ability and accuracy for gastric cancer patients undergoing radical gastrectomy.

Lymph node ratio as a novel and simple prognostic factor in advanced gastric cancer

TNM staging is no doubt the most critical prognostic factors, representing tumor (T)/lymph node metastasis (N)/distant metastasis (M) in gastric cancer. Lymph node ratio-based N system (Nr) has been repeatedly reported to be of prognostic relevance in advanced gastric cancer independent of stage in the multivariate analysis world-wide, and proposed as more sophisticated than N with regard to predicting accurate prognosis. As a result, proposed TNrM system may predict survival more accurately than the present TNM staging system for patients undergoing limited lymph node analysis. It could adjust stage migration when the lymph node number was used as staging factor. Although correlation of the number of metastatic lymph nodes and lymph node ratio is obvious, biological characteristics other than that could also have been reflected on. It may indicate how successful the operation of lymph node dissection was, or it may be revealing the potential of the patient's lymph node immune-reaction. Recently, high lymph node ratio is closely associated with EGFR expression in advanced gastric cancer. When efficiency of applying lymph node ratio as a biomarker is verified and confirmed in an expansive research, and when cancer causing molecules are identified, as well as the competence as a treatment target is studied, the new biomarker, namely, lymph node ratio, could find itself in a limelight in gastric cancer treatment in the future.

Prognostic Performance of Different Lymph Node Staging Systems After Curative Intent Resection for Gastric Adenocarcinoma

OBJECTIVE

To compare the prognostic performance of American Joint Committee on Cancer/International Union Against Cancer seventh N stage relative to lymph node ratio (LNR), log odds of metastatic lymph nodes (LODDS), and N score in gastric adenocarcinoma.

BACKGROUND

Metastatic disease to the regional LN basin is a strong predictor of worse long-term outcome following curative intent resection of gastric adenocarcinoma.

METHODS

A total of 804 patients who underwent surgical resection of gastric adenocarcinoma were identified from a multi-institutional database. The relative discriminative abilities of the different LN staging/scoring systems were assessed using the Akaike's Information Criterion (AIC) and the Harrell's concordance index (c statistic).

RESULTS

Of the 804 patients, 333 (41.4%) had no lymph node metastasis, whereas 471 (58.6%) had lymph node metastasis. Patients with ≥N1 disease had an increased risk of death (hazards ratio = 2.09, 95% confidence interval: 1.68-2.61; P < 0.001]. When assessed using categorical cutoff values, LNR had a somewhat better prognostic performance (C index: 0.630; AIC: 4321.9) than the American Joint Committee on Cancer seventh edition (C index: 0.615; AIC: 4341.9), LODDS (C index: 0.615; AIC: 4323.4), or N score (C index: 0.620; AIC: 4324.6). When LN status was modeled as a continuous variable, the LODDS staging system (C index: 0.636; AIC: 4304.0) outperformed other staging/scoring systems including the N score (C index: 0.632; AIC: 4308.4) and LNR (C index: 0.631; AIC: 4225.8). Among patients with LNR scores of 0 or 1, there was a residual heterogeneity of outcomes that was better stratified and characterized by the LODDS.

CONCLUSIONS

When assessed as a categorical variable, LNR was the most powerful manner to stratify patients on the basis of LN status. LODDS was a better predicator of survival when LN status was modeled as a continuous variable, especially among those patients with either very low or high LNR.

Prognostic Value of Metastatic No.8p LNs in Patients with Gastric Cancer

Background. To evaluate prognostic value of metastatic No.8p LNs in patients with gastric cancer. Methods. From August 2002 to December 2011, a total of 284 gastric cancer patients who underwent gastrectomy with No.8p LNs dissection were analyzed retrospectively in this study. Patients were divided into two groups according to the status of No.8p LNs. Clinicopathological features were collected to conduct the correlation analysis. Follow-up was carried out up to December 31st, 2014. Overall survival was analyzed. Results. Out of 284 patients, metastatic No.8p LNs were found in 24 (8.5%) patients. Compared with other 260 cases, these patients suffered morphologically larger tumor (P = 0.003), node stage (P = 0.000), and metastatic stage (P = 0.000). The 3-year overall survival rate was 26% in No.8p-positive group and 53% in No.8p-negative group. No significant difference of cumulative survival rates existed between the No.8p-positive group and No.8p-negative stage IV group (26% versus 28%, P = 0.923). Patients with other distant metastasis or not in No.8p+ group had similar cumulative survival rates (24% versus 28%, P = 0.914). Conclusions. Positive No.8p LNs were a poor but not an independent prognostic factor for patients with GC and should be recognized as distant metastasis.

The positive impact of surgeon specialization on survival for gastric cancer patients after surgery with curative intent

BACKGROUND

Many studies have affirmed the survival benefit for cancer patients treated by specialized surgeons.

METHODS

A total of 967 patients with gastric cancer (GC) who underwent gastrectomy with curative intent in our center were enrolled. Patients were categorized into two groups based on surgeon specialization: the specialized group (SG) and nonspecialized group (NSG). To overcome bias due to the different distribution of covariates for the two groups, a one-to-one match was applied using propensity score analysis. After matching, prognosis and recurrence data were analyzed.

RESULTS

After one-to-one matching, 261 patients in the SG and 261 patients in the NSG had the same characteristics excluding factors associated with surgery. In multivariate analysis for the whole study series, surgeon specialization was an independent prognostic factor for GC patients after surgery. Patients in the SG demonstrated a significantly higher 5-year overall survival than those in the NSG (50.7 vs. 37.2 %, p = 0.001). With the strata analysis, significant prognostic differences between the two groups were only observed in patients at stage IIIa-b or N1-2. The proportion of locoregional recurrence was greater in the NSG than in the SG.

CONCLUSION

GC patients treated by specialized surgeons tended to have a better prognosis and lower locoregional recurrence rate. Surgeon specialization was an independent prognostic factor for GC patients after surgery. GC should be treated by specialized surgeons in large-volume centers.

The development of the TNM classification of gastric cancer

The first tumor, node, metastasis (TNM) classification for stomach tumors was published in the second edition of the TNM classification of malignant tumors in 1974 and was followed by additional editions up to the seventh edition published in 2010. In the Buffalo Meeting 2008 a harmonization between the Eastern (Japanese) and Western stomach tumor classification was achieved with only minor remaing differences. The present TNM classification of stomach tumors has been criticized but it can be considered generally accepted worldwide. For generating data based on this new TNM classification it is important to correctly use TNM and pTNM. The decions on therapy and the estimation of prognosis are based on TNM. New molecular factor studies will be correlated and based on the results of the TNM classification.

Prognostic value of metastatic lymph node ratio as an additional tool to the TNM stage system in gastric cancer

BACKGROUND

Gastric cancer is one of most common malignancies in the world. Currently the prognostic prediction is entirely based on the TNM staging system. In this study, we evaluated whether metastatic lymph node ratio (rN) at the time of surgery would improve the prognostic prediction in conjunction with the TNM staging system.

METHODS

This retrospective study includes 745 patients, who had been referred for surgery due to gastric cancer between 1995 and 2007 and had at least 15 lymph nodes examined at the time of surgery without preoperative treatment. Clinicopathologic features and overall survival were analyzed using univariate and multivariate modes to identify the risk factors for overall survival.

RESULTS

Median overall survival of all patients analyzed is 57.8 months and 5-year overall survival is 49.5%. Tumor site, macroscopic type, pTNM stage, and rN stage are identified as independent prognostic factors. Increased positive lymph node ratio correlates with shorter survival in all patients and in each T and N stage. In stage III gastric cancer patients, rN stage shows additional prognostic value on overall survival (p < 0.001).

CONCLUSIONS

rN stage is a simple and promising prognostic factor of gastric cancer after surgery in addition to the TNM stage system especially in stage III patients. But the independent prognostic value of rN stage in stage I, II and IV gastric cancer is yet to be determined.

N3 subclassification incorporated into the final pathologic staging of gastric cancer: a modified system based on current AJCC staging

The seventh edition of the American Joint Committee on Cancer (AJCC) TNM classification system for gastric cancer (GC) was established in 2009. We assessed the unmet medical needs of patients with the N3 classification of the seventh TNM staging system by comparing survival according to the extent of nodal involvement, with a particular focus on the cutoff points for the number of involved nodes in the N3 classification. We retrospectively reviewed 3178 patients with GC who were registered in the GC database of the Department of General Surgery at the Chang Gung Memorial Hospital between 1994 and 2010. Among them, 884 patients undergoing curative intent resection had N3 lymph node involvement. The clinicopathological features and surgical outcomes were compared among all patients with GC and between the N3a and N3b groups. N3b might impose GC patients with poor clinical outcome. We proposed a modified staging system, based on AJCC seventh edition, accordingly. T1-3N3 might be not simply categorized into stage IIIA as seventh AJCC suggested. Taking N3a and N3b into consideration, T1-3N3 might be further categorized into stage IIIB and IIIC, respectively, as we proposed, based on survival analysis. In addition, T4bN3bM0 is as dismal as M1 disease. In our proposed staging system, good discriminations between different stages are still maintained. The N3 category should be subclassified as N3a or N3b due to the survival differences. Furthermore, T1-3N3aM0 could be categorized as stage IIIB, T1-3N3bM0 could be categorized as stage IIIC, T4aN3bM0 could be categorized as stage IIID, and T4bN3bM0 might be regarded as stage IV as we proposed.

Prognostic prediction in gastric cancer patients without serosal invasion: comparative study between UICC 7(th) edition and JCGS 13(th) edition N-classification systems

OBJECTIVE

T-stage and N-stage have been proven to be the most important factors influencing survival in gastric cancer patients, and have been accepted for use in the Japanese Classification of Gastric Carcinoma (JCGC) and the Union International Cancer Control (UICC-TNM) staging systems. The purpose of this study was to compare the prognostic values of the different N classification systems in gastric cancer patients without serosal invasion.

METHODS

We retrospectively compared the clinicopathological results of 1,115 patients with primary gastric cancer who underwent curative gastric resection.

RESULTS

Serosal invasion was identified in 212 of 1,115 patients (19.0%), and it was associated with lymph node metastasis according to the JCGC(13th) (P<0.001) and TNM(7th) (P<0.001) systems. The 5-year survival rate for the serosal invasion-negative patients (78.2%) was significantly higher than that for the serosal invasion-positive patients (31.1%) (P<0.001). Multivariate Cox regression survival analysis showed that depth of invasion (P=0.013), 13(th) JCGC PN stage (P<0.001), and 7(th) TNM PN stage (P<0.001) were independent prognostic factors for serosal invasion-negative gastric cancer patients.

CONCLUSIONS

The prognosis of gastric cancer patients with serosal invasion is very poor. Both the 13(th) JCGC and 7(th) TNM N-staging systems were able to accurately estimate the prognosis of gastric cancer patients, but the 7(th) TNM system was simpler and easier to use.

Prognostic value of the lymph node ratio in stage III gastric cancer patients undergoing radical resection

OBJECTIVE

The aim of this study was to investigate the prognostic value of metastatic lymph node ratio (LNR) in patients having radical resection for stage III gastric cancer.

METHODS

A total of 365 patients with stage III gastric cancer who underwent radical resection between 2002 and 2008 at Tianjin Medical University Cancer Institute and Hospital were analyzed. The cut-point survival analysis was adopted to determine the appropriate cutoffs for LNR. Kaplan-Meier survival curves and log-rank tests were used for the survival analysis.

RESULTS

By cut-point survival analysis, the LNR staging system was generated using 0.25 and 0.50 as the cutoff values. Pearson's correlation test revealed that the LNR was related with metastatic lymph nodes but not related with total harvested lymph nodes. Cox regression analysis showed that depth of invasion and LNR were the independent predictors of survival (p<0.05). There was a significant difference in survival between each pN stages classified by the LNR staging, however no significant difference was found in survival rate between each LNR stages classified by the pN staging.

CONCLUSIONS

The LNR is an independent prognostic factor for survival in stage III gastric cancer and is superior to the pN category in TNM staging. It may be considered as a prognostic variable in future staging system.

Prognostic impact of lymph node retrieval and ratio in gastric cancer: a U.S. single center experience

INTRODUCTION

Increased lymph node (LN) retrieval for gastric cancer has been associated with improved overall survival (OS). This study examines the impact of number of examined LN (eLN) and lymph node ratio.

METHODS

Patients referred for surgical care of gastric cancer were stratified by number of eLN, positive LNs (LN+), and lymph node ratio (LN+/eLN). Clinicopathologic factors were compared; OS and disease-free survival (DFS) were the primary endpoints.

RESULTS

From 1997 to 2012, 222 patients, median age 67 (range, 17-92) years, were analyzed. Of 220 (99 %) explored, 164 (74 %) underwent resection. Median OS was 22 (range, 0.3-140) months. Perineural and lymphovascular invasion and poor differentiation adversely affected OS, p < 0.05. A median 14 eLN (range, 0-45), with median 1 LN+ (range, 0-31), was observed. There were no OS or DFS differences when comparing the eLN groups. Both OS and DFS were impacted by LN+. Lymph node ratio demonstrated worse median OS with increasing ratio: 49 months (0) to 37 months (0.01-0.2), 27 months (0.21-0.5), and 12 months (>0.5), p < 0.0001. DFS was similar: 35 months (0), decreasing to 22 months (0.01-0.2), 13 months (0.21-0.5), and 7 months (>0.5), p < 0.0001.

CONCLUSION

Number of eLN did not impact survival, while LN+ adversely affected survival. Lymph node ratio may predict prognosis better than number of eLN or LN+ in gastric cancer.

Improved survival after adding dissection of the superior mesenteric vein lymph node (14v) to standard D2 gastrectomy for advanced distal gastric cancer

BACKGROUND

Extended lymph node dissection in gastric cancer (D3) was proven to have no survival benefit compared with a D2 dissection, but whether adding the superior mesenteric nodes (No. 14v) to the dissection provides survival benefit for gastric cancer patients remains controversial.

METHODS

From April 2001 to June 2007, 1,661 patients underwent curative resection for middle or lower third gastric cancer. Patients were grouped according to No. 14v lymphadenectomy (14vD+/14vD-). Clinicopathologic characteristics and treatment-related factors were compared between the groups. Overall survival according to the clinical stage (Union for International Cancer Control tumor-node-metastasis staging 6th edition) was analyzed using the Cox proportional hazard model.

RESULTS

The incidence of No. 14v lymph node metastasis was 5.0%. There was no difference in morbidity or mortality between the 14vD+ and the 14vD- groups. The proportion of locoregional recurrence was greater in 14vD- group (P = .018). In clinical stages I and II, 14v lymph node dissection did not affect overall survival; in contrast, 14v lymph node dissection was an independent prognostic factor in patients with clinical stage III/IV gastric cancer (hazard ratio, 0.58; 95% confidence interval, 0.38-0.88; P = .01).

CONCLUSION

Extended D2 gastrectomy including No. 14v lymph node dissection seems to be associated with improved overall survival of patients with clinical stage III/IV gastric cancer in the middle or lower third of the stomach.

Short-term outcome of total laparoscopic distal gastrectomy for overweight and obese patients with gastric cancer

BACKGROUND

Laparoscopic distal gastrectomy for gastric cancer has been firmly established in recent decades but still is a difficult procedure, especially for obese patients, as with open surgery. This study aimed to evaluate the perioperative outcome of total laparoscopic distal gastrectomy (TLDG) for early gastric cancer patients with a body mass index (BMI) exceeding 25 kg/m(2) and to consider countermeasures to this.

METHODS

Perioperative outcomes were compared between 42 patients with a BMI exceeding 25 kg/m(2) [overweight or obese group (OWG)] and 174 patients with a BMI lower than 25 kg/m(2) [normal or underweight group (NWG)] who underwent TLDG between September 2010 and December 2012.

RESULTS

The BMI was 26.0 ± 1.4 kg/m(2) in the OWG group and 22.0 ± 2.1 kg/m(2) in the NWG group (P < 0.001). The groups did not differ in terms of age, sex, American Society of Anesthesiologists score, presence of diabetes, number of retrieved lymph nodes, number of metastatic lymph nodes, or metastatic lymph node ratio. The two groups did not differ significantly with respect to the extent of lymph node dissection [OWG: D1 (11.9 %), D1+ (66.7 %), D2 (21.4 %) vs NWG: D1 (5.2 %), D1+ (51.7 %), D2 (43.1 %); P = 0.020] or tumor size (OWG: 25.5 ± 20.2 mm vs NWG: 33.0 ± 17.2 mm; P = 0.037). Differences in operation time (OWG: 212 ± 31 min vs NWG: 200 ± 35 min; P = 0.005) and estimated blood loss (OWG: 15 ± 22 ml vs NWG: 10 ± 34 ml; P = 0.013) seemed to have a minimal impact clinically. Postoperative complications including infectious complications and recovery after surgery did not differ between the two groups.

CONCLUSIONS

For overweight and obese patients, TLDG was managed safely. The procedure was considered to be difficult but sufficiently feasible.