Prognostic impact of metastatic lymph node ratio in advanced gastric cancer from cardia and fundus

Machine learning-based reconstruction of prognostic staging for gastric cancer patients with different differentiation grades: A multicenter retrospective study

BACKGROUND

The prognosis of gastric cancer (GC) patients is poor, and an accurate prognostic staging system would help assess patients' prognostic status before treatment and determine appropriate treatment strategies.

AIM

To develop positive lymph node ratio (LNR) and machine learning (ML)-based staging systems for GC patients with varying differentiation.

METHODS

This multicenter retrospective cohort study included 11772 GC patients, with 5612 in the training set (Harbin Medical University Cancer Hospital) and 6160 in the validation set (Surveillance, Epidemiology, and End Results Program database). X-tile software identified optimal cutoff values for the positive LNR, and five ML models were developed using pT and LNR staging. Risk scores were divided into seven stages, constructing new staging systems tailored to different tumor differentiation levels.

RESULTS

In both the training and validation sets, regardless of the tumor differentiation level, LNR staging demonstrated superior prognostic stratification compared to pN. Extreme Gradient Boosting exhibited better predictive performance than the other four models. Compared to tumor node metastasis staging, the new staging systems, developed for patients with different degrees of differentiation, showed significantly better predictive performance.

CONCLUSION

The new positive lymph nodes ratio staging and integrated staging systems constructed for GC patients with different differentiation grades exhibited better prognostic stratification capabilities.

Lymph Node Ratio Improves Prediction of Overall Survival in Esophageal Cancer Patients Receiving Neoadjuvant Chemoradiotherapy: A National Cancer Database Analysis

OBJECTIVE

This study aimed to propose a revised ypN (r-ypN) classification based on lymph node ratio (LNR) and to examine its prognostic value in postneoadjuvant esophageal cancer.

BACKGROUND

A new postneoadjuvant pathologic (ypTNM) staging classification has been introduced for esophageal cancer. However, the ypN classification currently defined by the number of positive lymph nodes is influenced by the extent of lymphadenectomy.

METHODS

Data on 7195 esophageal cancer patients receiving neoadjuvant chemoradiation were extracted from the National Cancer Database (NCDB). Four r-ypN stages were defined by 3 LNR thresholds (0%, 10%, and 20% using X-tile software). A revised ypTNM (r-ypTNM) classification was developed by solely changing N categories. Kaplan-Meier method and Cox proportional hazards models were used for survival analyses. Akaike information criterion (AIC) and Harrell's concordance index ( C -index) were used to compare the predictive performance of the current and the revised classification. External validation was performed using an independent cohort from the NEOCRTEC5010 clinical trial.

RESULTS

Both ypN ( P <0.001) and r-ypN ( P <0.001) were independent prognostic factors of overall survival (OS) for esophageal cancer patients. Kaplan-Meier curves demonstrated a better discrimination with r-ypN than ypN categories. Within each ypN category (except ypN3), OS was significantly different comparing r-ypN strata; however, there were no differences between ypN strata within each r-ypN category (except r-ypN3). r-ypN (AIC: 60752 vs 60782; C -index: 0.591 vs 0.587) and r-ypTNM (AIC: 60623 vs 60628; C -index: 0.613 vs 0.610) showed better predictive performance than the current staging system, with a lower AIC (better calibration) and higher C -index (improved discrimination). This advantage was also confirmed by external validation using the NEOCRTEC5010 cohort.

CONCLUSIONS

LNR showed better performance than ypN in predicting OS of esophageal cancer patients after neoadjuvant chemoradiation and may be an improvement on the current staging system.

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.

The impact of the number of harvested central lymph nodes on the lymph node ratio

OBJECTIVE

The purpose of this study was to analyze the impact of lymph node harvest on the lymph node ratio (LNR).

METHODS

We retrospectively reviewed 106 patients diagnosed preoperatively with PTMC (papillary thyroid microcarcinoma), no evidence of central or lateral neck nodal metastasis, and who underwent a total thyroidectomy and bilateral central lymph node neck dissection (CND).

RESULTS

The median number of retrieved lymph nodes in the central compartments was 7±6.59 (range: 1-42). The mean number of metastatic lymph nodes in the central compartments on pathology was 1.1±1.79 (range: 0-7). The high node volume group (>7) had a significantly higher rate of central lymph node (CLN) metastasis than the low node volume group (≤7) in the final pathologic report (p<0.001). With the linear regression method, the number of CLN metastasis increased as the number of retrieved lymph nodes increased (correlation coefficient=0.286, p=0.003). The multivariate analysis confirmed the number of retrieved lymph nodes in the central compartments was a risk factor for high LNR (p=0.008, odds ratio 3.737). The rates of vocal fold palsy and hypoparathyroidism did not differ according to the number of retrieved lymph nodes.

CONCLUSION

The lymph node ratio in the final pathologic report is larger when a greater number of lymph nodes are retrieved during the central compartment neck dissection.

Integrated analysis of the prognostic role of the lymph node ratio in node-positive gastric cancer: A meta-analysis

BACKGROUND

The lymph node ratio (LNR) as a prognostic parameter for gastric cancer has yet to be fully validated in the current tumor node metastasis staging system. We assessed the prognostic role of LNR in lymph node-positive gastric cancer through a meta-analysis.

MATERIALS AND METHODS

PubMed and EMBASE were searched for relevant studies up until December 2016. The effect measure for meta-analysis of primary outcomes was the hazard ratio (HR) for overall survival. Pooled HRs and 95% confidence intervals were calculated using random effects models. The I² statistic was used to measure heterogeneity. Subgroup analysis and meta-regression were chosen to illustrate the potential heterogeneity of the risk factors of outcomes. Publication bias was assessed using Egger's test and Begg's funnel plots. Sensitivity analysis was applied to evaluate the origin of the heterogeneity.

RESULTS

We included 27 studies in this meta-analysis. Higher LNRs were significantly associated with a shorter overall survival (OS). High heterogeneity among the studies was identified (I² = 85.6), and the publication bias was moderate. Subgroup analysis showed similar results, and elevated LNR was associated with late-stage gastric cancer and indicative of a worse prognosis. Univariate meta-regression analysis of OS indicated that both treatment type and ethnicity may be causes of heterogeneity in patients with gastric cancer (p values were 0.005 and 0.008, respectively).

CONCLUSION

LNR was associated with a significantly poorer OS and LNR was an independent predictor of survival in patients with gastric cancer. LNR should be added as one of the parameters to be used in future tumor staging classification systems.

Assessment of Lymph Node Ratio to Replace the pN Categories System of Classification of the TNM System in Esophageal Squamous Cell Carcinoma

INTRODUCTION

The seventh edition of the TNM staging system for esophageal cancer outlined by the American Joint Committee on Cancer (AJCC) defines the N classification on the basis of the number of metastatic lymph nodes. However, this classification is dependent on the actual number of examined lymph nodes. Here in this study, we have focused on revising this N classification system with the metastatic lymph nodes ratio (LNR) and also assessing whether this modification to the current AJCC staging system can better define the prognostic characteristics of esophageal squamous cell carcinoma (ESCC).

METHODS

We retrospectively reviewed 916 patients with ESCC who underwent curative resection. Prognostic performance of two staging systems was compared using the Akaike information criterion value and receiver operating characteristics curve. In addition, decision curve analysis evaluated the clinical practical usefulness of the prediction models by quantifying their net benefits.

RESULTS

The univariate and multivariate Cox regression analyses indicated that LNR was an independent risk factor for overall survival. The modified staging system based on LNR had better discriminatory ability, monotonicity, homogeneity, and stratification than the TNM staging system in determining the prognosis of patients with ESCC. However, the decision curves analysis suggested that the modified staging based on LNR has poor clinical practical value over the AJCC TNM staging system.

CONCLUSIONS

LNR can supplement the pN categorization system for more effective evaluation of prognosis. But the modified staging system based on LNR has a poor clinical practical value for patients with ESCC compared with the current TNM system and is not superior to AJCC pN staging for ESCC.

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.

Comparison of five staging systems of lymph node metastasis in the gastric carcinoma

BACKGROUND

The presence of metastatic lymph nodes is the most important prognostic factor for gastric carcinoma; however, the optimal system for the accurate staging of lymph node metastasis for patients with gastric cancer remains controversial. This study was designed to compare five systems in relation to the N classification of gastric carcinoma.

MATERIALS AND METHODS

This multicentric historical cohort study was conducted on 148 patients with M0 gastric adenocarcinoma who underwent gastrectomy in, five referral hospitals in Iran. Lymph nodes were sectioned, stained with hematoxyl in and eosin. The lymph node status was classified according to the five systems which are: The number of involved lymph nodes (TNM staging), metastatic lymph node ratio (N ratio), and the largest involved lymph node size, largest metastatic nest size and largest metastatic nest to lymph node size ratio.

RESULTS

Patients were classified into significant prognostic groups by the five N classification method including the TNM method, N ratio (0, ≤0.15, 0.15-0.4, >0.4), largest involved lymph node size (0, ≤5, 5-11, >11 mm), Largest metastatic nest size (≤1, 1-7.5, >7.5 mm) and largest metastatic nest to lymph node size ratio (≤0.3, 0.3-0.9, >0.9). All of the above systems remained as independently significant prognostic factors in terms of overall and disease free survival time.

CONCLUSION

Among the N staging systems we recommend the metastatic lymph node ratio and largest metastatic nest to lymph node size systems, since they are reproducible, simple, have good survival applicability, have prognostic value and include less stage migration especially in patients whom fewer than 15 lymph nodes are dissected.

Number of central lymph node metastasis for predicting lateral lymph node metastasis in papillary thyroid microcarcinoma

BACKGROUND

The purpose of this study was to present our evaluation of the relationship between the number of positive central lymph nodes and lateral lymph node metastasis in patients with papillary thyroid microcarcinoma (PTMC).

METHODS

Up to 141 patients with PTMC were divided into 3 groups according to different positive central lymph node classifications as follows: group A, no positive central lymph node; group B, 1 positive central lymph node; and group C, 2 or more positive central lymph nodes.

RESULTS

Incidence of lateral lymph node metastasis was 30.5% (43 of 141). It was significantly high in group C compared with groups A and B, although there was no significant difference between groups A and B. Number of positive central lymph node ≥2, underlying Hashimoto thyroiditis, and extrathyroidal extension were the independent predictive factors for lateral lymph node metastasis on multivariate analysis.

CONCLUSION

Lateral lymph node metastasis was mainly observed in patients with ≥2 positive central lymph nodes, which is an independent predictive factor for lateral lymph node metastasis. Therefore, ≥2 positive central lymph nodes may be valuable in predicting lateral lymph node metastasis.

Comparison of two different adjuvant treatment modalities for pN3 gastric cancer patients after D2 lymph node dissection: can we avoid radiotherapy in a subgroup of patients?

Adjuvant chemoradiotherapy (CRT) is the standard of care for gastric cancer patients in the USA. However, in countries where D2 lymph node dissection is performed, the effect of radiotherapy on locoregional recurrence is controversial. The aim of this study is to compare the outcomes in pN3 gastric cancer patients following two adjuvant treatment modalities: chemotherapy (CT) and CRT after D2 lymph node dissection. Between 2005 and 2009, 71 gastric cancer patients who underwent D2 lymph node dissection and had pTanyN3M0 stage (according to AJCC 6th edition) were identified. Fifty-three patients were treated with CT and 18 patients received CRT. CRT consisted of bolus fluorouracil (FU) 425 mg/m(2) and leucovorin 20 mg/m(2) before, after, and during radiotherapy. For the CT arm, treatment protocols consisted of combination therapies involving FU and cisplatin as the backbone. Median overall survival (OS) and disease-free survival (DFS) rates for all patients were 26.3 months (15-37.7 months) and 12.5 months (8-17.1 months). Median OS in CT arm was 26.8 months and it was 34.2 months for CRT arm (p = 0.74). DFS rates did not differ statistically either (p = 0.56, 12.5 and 15.2 months for CT and CRT, respectively). Locoregional recurrence rates were also similar (p = 0.63). Only metastatic/dissected lymph node ratio (≥0.75) was identified as a prognostic factor in both univariate and multivariate analyses for DFS. Comparison of CT versus CRT for N3 stage gastric cancer patients with D2 lymph node dissection did not reveal any statistically significant difference in survival rates and locoregional recurrence.

Ratio between negative and positive lymph nodes is suitable for evaluation the prognosis of gastric cancer patients with positive node metastasis

OBJECTIVE

To date, there is no consensus to evaluate the most appropriate category of the nodal metastasis for precise predication the prognosis of gastric cancer patients with positive node metastasis after curative surgery.

METHODS

We retrospectively analyzed the clinicopathologic characteristics and overall survival (OS) of 299 gastric cancer patients with positive node metastasis after curative surgery for evaluation the optimal category of the nodal metastasis.

RESULTS

With the univariate and multivariate survival analyses, the depth of primary tumor invasion was identified as the independent predicators with the OS of 299 gastric cancer patients with nodal metastasis postoperatively, as were the number of positive lymph nodes (PLNs), the number of negative lymph nodes (NLNs), and the ratio between negative and positive lymph nodes (RNPL). The RNPL was identified to be more suitable for predication the OS of gastric cancer patients with positive node metastasis than the ratio between positive and dissected lymph nodes (RPDL) by using the stratum procedure of survival analysis. Besides, we found both PLNs and NLNs were independently correlated with OS of gastric cancer patients with nodal metastasis when RNPL, instead of RPDL, was controlled in the partial correlation model.

CONCLUSIONS

RNPL, a new category of the nodal metastasis, was suitable for predication the OS of gastric cancer patients with nodal metastasis after curative resection, as were the PLNs, and NLNs.

Prognostic implications of lymph node metastases in carcinoma of the body and tail of the pancreas

OBJECTIVE

The current classification of pancreatic cancer is based only on anatomic location of metastatic lymph nodes (LNs). On the other hand, the number of metastatic LNs has been used in staging of colorectal, esophageal, and gastric cancers. The aim of this study was to assess the prognostic impact of the number or ratio of the metastatic LNs in pancreatic body and tail carcinoma.

METHODS

Eighty-five patients with pancreatic body and tail adenocarcinoma who underwent pancreatectomy were included. Location, number, ratio of metastatic LNs, and the survival of patients were analyzed.

RESULTS

Forty patients with LN metastasis had poor prognosis (P = 0.007). The prognoses of patients with 5 or more metastatic LNs were poorer than those with less than 5 metastatic LNs (P = 0.046), and patients with a metastatic LN ratio of 0.2 or more had the worst prognosis. Multivariate analysis revealed that 5 or more metastatic LNs and metastatic LN ratio of 0.2 or more were independent prognostic factors for survival (P = 0.0015 and P = 0.014, respectively).

CONCLUSION

These results indicate that the number and the ratio of metastatic LNs can be used to predict poor patient survival and as a staging strategy.

Lymph node examination among patients with gastric cancer: variation between departments of pathology and prognostic impact of lymph node ratio

INTRODUCTION

At least 15 lymph nodes should be retrieved for proper TNM-staging in gastric cancer. We evaluated nodal harvest and examined its relation to stage distribution and survival at a population-based level, including the value of N-ratio (metastatic/evaluated) as a staging modality.

METHODS

All patients resected for primary M0 gastric cancer diagnosed in 1999-2007 in the Dutch Eindhoven Cancer Registry area were included (N = 880). Determinants of lymph node evaluation and their relationship with stage and survival were assessed in multivariable regression analyses. N-ratio categories were determined (N-ratio 0, 0%; N-ratio 1, 0.1%-19%; N-ratio 2, 20%-29%; N-ratio 3, ≥30%)

RESULTS

The median number of lymph nodes examined was 7, dependent on N-category (N0: 7; N+: 8). It varied between departments of pathology from 5 to 9. This variation remained after adjustment for relevant patient- and tumour factors. Stage distribution differed between pathology departments (proportion N0 ranging from 14% to 21%, p = 0.003). Among resected patients with N0M0 disease and <7 nodes examined, 5-year survival was 56%, compared to 69% among patients with ≥7 nodes examined (p = 0.012). Five-year survival for N-ratio 0 was 58%, N-ratio 1 50%, N-ratio 2 18% and N-ratio 3 11% (p < 0.0001), while 5-year survival ranged from 58% for N0, 17% for N1, and 11% for N2/3 (p < 0.0001).

CONCLUSION

In this series of patients with a relatively low number of evaluated lymph nodes, a high prognostic accuracy of N-ratio was found. However, improvement in nodal assessment is mandatory.

Prognostic significance of the metastatic lymph node ratio in gastric cancer patients

BACKGROUND

Lymph node metastasis is considered one of the most important prognostic factors in gastric cancer. However, the optimal system for accurate staging of lymph node metastasis for patients with gastric cancer remains controversial. This study was designed to investigate the prognostic significance of the metastatic lymph node ratio (MLR), which is calculated by dividing the number of metastatic lymph nodes by the total number of nodes harvested from patients with gastric cancer.

METHODS

We retrospectively analyzed the clinical data of 186 consecutive patients diagnosed with gastric cancer who underwent curative gastrectomy at our hospital. The lymph node status was classified according to three systems:the International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) system; the Japanese Gastric Cancer Association (JGCA) system; and an MLR-based system (MLR0: 0, MLR1: 0.01-0.19, MLR2: >or=0.2). The influence of the MLR on patient survival was determined using univariate Kaplan-Meier survival analysis, the generalized Wilcoxon test, and analysis with the multivariate Cox proportional hazards model.

RESULTS

The 5-year survival rate of the patients with MLR0, MLR1, and MLR2 was 88.6%, 59.4%, and 13.4%, respectively. In addition to the MLR, the UICC/AJCC N category,JGCA n category, tumor stage (pT category), and tumor diameter significantly influenced the 5-year survival rate, as determined by univariate analysis. Multivariate analyses revealed that of the three factors used to stage lymph node involvement, MLR was the most significant prognostic factor.

CONCLUSIONS

The MLR is an important and easy-to-assess prognostic factor that should be considered for staging lymph node metastasis in patients with gastric cancer.

Prognostic factors for patients after curative resection for proximal gastric cancer

The factors influencing the long-term survival of patients with proximal gastric cancer (PGC) after curative resection were investigated. Data from 171 patients who underwent curative resection for PGC were retrospectively analyzed. The patients were grouped according to the clinicopathological factors and operative procedures. The tumor depth (T stage) and lymph node metastasis (pN stage) were graded according to the fifth edition of TNM Staging System published by UICC in 1997. The metastatic lymph node ratio (MLR) was divided into four levels: 0%, <10%, 10%-30% and >30%. The data of survival rate were analyzed by Kaplan-Meier method (log-rank test) and Cox regression model. The 5-year overall survival rate of 171 patients was 37.32%. The univariate analysis demonstrated that the survival time of the postoperative patients with PGC was related to tumor size (chi2=4.57, P=0.0325), gross type (chi2=21.38, P<0.001), T stage (chi2=27.91, P<0.001), pN stage (chi2=44.72, P<0.001), MLR (chi2=61.12, P<0.001), TNM stage (chi2=44.91, P<0.001), and range of gastrectomy (chi2=4.36, P=0.0368). Multivariate analysis showed that MLR (chi2=10.972, P=0.001), pN stage (chi2=6.640, P=0.010), TNM stage (chi2=7.081, P=0.007), T stage (chi2=7.687, P=0.006) and gross type (chi2=6.252, P=0.012) were the independent prognostic factors. In addition, the prognosis of patients who underwent total gastrectomy (TG) was superior to that of patients who underwent proximal gastrectomy (PG) for the cases of tumor>or=5 cm (chi2=6.31, P=0.0120), Borrmann III/IV (chi2=7.96, P=0.0050), T4 (chi2=4.57, P=0.0325), pN2 (chi2=5.52, P=0.0188), MLR 10%-30% (chi2=4.46, P=0.0347), MLR>30% (chi2=13.34, P=0.0003), TNM III (chi2=14.05, P=0.0002) or TNM IV stage (chi2=4.37, P=0.0366); and combining splenectomy was beneficial to the cases of T3 (chi2=5.68, P=0.0171) or MLR>30% (chi2=6.11, P=0.0134). It was concluded that MLR, pN stage, TNM stage, T stage, and gross type had advantages in providing a precise prognostic evaluation for patients undergoing curative resection for PGC, in which MLR was the most valuable index. TG and combining splenectomy were useful to improve the prognosis to patients with PGC of TNM III/IV stage, serosa invasion, or extensive regional lymph node metastasis.

The prognostic analysis of lymph node-positive gastric cancer patients following curative resection

BACKGROUND

The purpose of this study was to evaluate the appropriate prognostic indicators of lymph node-positive gastric cancer patients following curative resection.

METHODS

A retrospective study of 196 lymph node-positive patients who underwent radical gastrectomy (R0) for gastric cancer from January 1997 to December 2000 was analyzed statistically to identify the intensive indictors of prognosis.

RESULTS

In 196 evaluable patients, 5-year survival rate was 33.2%. A total of 4048 lymph nodes were examined (median, 20.6; range, 15-49), and 1661 lymph nodes were positive (median, 8.5; range, 1-37). The median survival was 29 months. With multivariate analysis, we found number and ratio of metastatic lymph nodes were associated with overall survival (OS) of lymph node-positive patients after curative surgery. However, we ultimately identified that ratio of metastatic lymph nodes was more appropriate to evaluate OS of lymph node-positive patients than number of metastatic lymph nodes by using the case-control matched fashion. One hundred forty-four (73.5%) patients had recurrence after curative surgery. The median disease-free time was 18 month, and the median survival after recurrence was 4 month. With multivariate analysis (logistic regression model), we found number of metastatic lymph nodes was associated with recurrence after curative surgery.

CONCLUSION

Ratio and number of metastatic lymph nodes were important indicators of OS and recurrence of lymph node-positive gastric cancer patients following curative resection, respectively.