Can lymph node ratio replace pn categories in the tumor-node-metastasis classification system for esophageal cancer? J Thorac Oncol. 2014; 9:1214-1221. [PMID: 25157776 DOI: 10.1097/jto.0000000000000216]

Pathologic lymph node ratio is a predictor of esophageal carcinoma patient survival: a literature-based pooled analysis

The positive lymph node ratio (LNR) has been suggested as a predictor of survival in patients with esophageal carcinoma (EC). However, existed evidences did not completely agree with each other. We sought to examine whether LNR was associated with overall survival (OS). Electronic database was searched for eligible literatures. The primary outcome was the relationship between LNR and OS, which was presented as hazard ratio (HR) with 95% confidence intervals (CIs). All statistical analyses were performed using STATA 11.0 software. A total of 18 relevant studies which involved 7,664 cases were included. Patients with an LNR of 0.3 or greater had an increased risk of death compared to those with an LNR of less than 0.3(HR = 2.33; 95% CI 2.03-2.68; P<0.01). Similarly, patients with an LNR greater than 0.5 was also associated with a decreased OS(HR = 1.95; 95% CI 1.52-2.50; P<0.01). No publication bias was found. This meta-analysis confirmed that LNR was a significant predictor of survival in patients with EC and should be considered in prognostication.

Log odds of positive lymph nodes is a novel prognostic indicator for advanced ESCC after surgical resection

BACKGROUND

To investigate the prognostic value of the log odds of positive lymph nodes (LODDS) in patients with advanced esophageal squamous cell carcinoma (ESCC) after surgical resection.

METHODS

Clinical data of 260 patients with advanced ESCC undergoing surgical resection were retrospectively reviewed. Univariate and multivariate analysis were done using the chi-square test and Cox regression model. Receiver-operating-characteristic (ROC) curve was used to compare the association of pathologic nodal (pN) and LODDS with 3- or 5-year overall survival (OS). The cut-point analyses were performed to determine whether there was a cutoff LODDS related to the greatest OS difference.

RESULTS

The mean follow-up duration was 30 months (range, 3 to 106 months). The 1-, 3-, 5-year OS rates were 70.0%, 41.9% and 30.3%, respectively. Univariate analyses indicated that the 5-year OS rates were 51.2%, 30.5%, 24.6%, and 14.2% in LODDS1, LODDS2, LODDS3, and LODDS4, respectively, and the median survival times were 68.7, 34.6, 24.0, and 14.6 months, respectively (P=0.000) for all patients, and subgroup analysis showed the effect did not change in 155 patients without lymph node (LN) metastasis (P=0.024). Multivariate analysis showed that LODDS [hazard ratio (HR) =1.309, P=0.003] to be independent and significant prognostic factors for all patients, so as in node-negative patients LODDS (HR =1.610, P=0.038). The AUC of LODDS stage (AUC =0.630) was larger than that of pN stage (AUC =0.621) in prediction of 3-year OS, however LODDS were smaller in prediction of 5-year OS (AUC =0.620, 0.631, respectively), and the differences were not statistically significant (P>0.05 all). Lastly, the step analysis identified the best cut-off point for LODDS as -1.2 that is significantly associated with the prognosis of the node-negative patients (P=0.024), and the ROC analysis also indicated that a cut-off value of -1.2 for LODDS provided the highest sensitivity and specificity interestingly.

CONCLUSIONS

LODDS may be suitable for evaluation of OS in advanced ESCC patients without LN metastasis.

Prognosis of patients with esophageal squamous cell carcinoma after esophagectomy using the log odds of positive lymph nodes

To compare the log odds of positive lymph nodes (LODDS) with the number of positive lymph nodes (pN), lymph node ratio (LNR), removed lymph node (RLN) count, and negative lymph node (NLN) count in determining the prognosis of patients with esophageal squamous cell carcinoma (ESCC) after esophagectomy. The records of patients with ESCC who received esophagectomy were retrospectively reviewed. The log-rank test was used to compare curves for overall survival (OS), and Cox regression analysis was performed to identify prognostic factors. The prognostic performance of the different lymph node staging systems were compared using the linear trend chi-square test, likelihood ratio chi-square test, and Akaike information criterion. A total of 589 patients were enrolled. Univariate Cox analysis showed that pN stage, LNR, RLN count, NLN count, and the LODDS were significantly associated with OS (p < 0.05 for all). Multivariate Cox analysis adjusted for significant factors indicated that LODDS was independent risk factor on overall survival (OS), and a higher LODDS was associated with worse OS (hazard ratio = 3.297, 95% confidence interval: 2.684–4.050, p < 0.001). The modified Tumor-LODDS-Metastasis staging system had better discriminatory ability, monotonicity, and homogeneity, and better optimistic prognostic stratification than the Tumor-Node-Metastasis staging system in determining the prognosis of patients with ESCC. The LODDS staging system was superior to other lymph node classifications in determining the prognosis of patients with ESCC after esophagectomy. LODDS may be incorporated into esophageal staging system if these results are eventually confirmed by other studies.

Extent of Lymphadenectomy Is Associated With Improved Overall Survival After Esophagectomy With or Without Induction Therapy

BACKGROUND

National Comprehensive Cancer Network (NCCN) guidelines recommend sampling 15 or more lymph nodes during esophagectomy. The proportion of patients meeting this guideline is unknown, as is its influence on overall survival (OS).

METHODS

Univariate analysis and logistic regression were performed to identify variables associated with sampling 15 or more lymph nodes among patients undergoing esophagectomy in the National Cancer Data Base (NCDB). The NCCN guideline was evaluated in Cox proportional hazards modeling, along with alternative lymph node thresholds. Positive to examined node (PEN) ratios were calculated, and OS was compared using Kaplan-Meier analysis.

RESULTS

From 2006 to 2012, only 6,961 of 18,777 (37.1%) patients undergoing esophagectomy had sampling of 15 or more lymph nodes. Variables associated with sampling 15 or more lymph nodes included income greater than or equal to $38,000, procedure performed in an academic facility, and increasing clinical T and N stages. Induction therapy was associated with a decreased likelihood of 15 or more lymph nodes being sampled. The largest decrease in mortality hazard in patients undergoing upfront esophagectomy was detected when 25 lymph nodes or more were sampled (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.67-0.89; p < 0.001), whereas for patients undergoing induction therapy, sampling of 10 or 15 or more lymph nodes was associated with optimal survival benefit (HR, 0.81; 95% CI, 0.74-0.90; p < 0.001). PEN ratios of 0 to 0.10 were associated with maximum survival benefit among all patients undergoing esophagectomy. For patients with a PEN ratio of 0, increases in OS were detected with higher lymph node sampling (85.3 months for sampling of 20 or more lymph nodes versus 52.0 months for sampling 1-9 lymph nodes; p < 0.001).

CONCLUSIONS

For patients undergoing upfront esophagectomy, there may be an increased survival benefit for examining 20 to 25 lymph nodes, which is higher than current recommendations. However, only a minority of patients are meeting current guidelines.

Metastatic lymph node ratio demonstrates better prognostic stratification than pN staging in patients with esophageal squamous cell carcinoma after esophagectomy

This study aimed to evaluate the prognostic significance of lymph node ratio (LNR) by establishing a hypothetical tumor-ratio-metastasis (TRM) staging system in patients with esophageal squamous cell carcinoma (ESCC). The records of 387 ESCC patients receiving curative esophagectomy were retrospectively investigated. The optimal cut-point for LNR was assessed via the best cut-off approach. Potential prognostic parameters were identified through univariate and multivariate analyses. A novel LNR-based TRM stage was proposed. The prognostic discriminatory ability and prediction accuracy of each system were determined using hazard ratio (HR), Akaike information criterion (AIC), concordance index (C-index), and area under the receiver operating characteristic curve (AUC). The optimal cut-points of LNR were set at 0, 0~0.2, 0.2~0.4, and 0.4~1.0. Multivariate Cox analysis indicated that the LNR category was an independent risk factor of overall survival (P < 0.001). The calibration curves for the probability of 3- and 5-year survival showed good consistency between nomogram prediction and actual observation. The LNR category and TRM stage yielded a larger HR, a smaller AIC, a larger C-index, and a larger AUC than the N category and TNM stage did. In summary, the proposed LNR category was superior to the conventional N category in predicting the prognosis of ESCC patients.

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.

Clinical Nomogram for Predicting Survival of Esophageal Cancer Patients after Esophagectomy

The aim of this study was to construct an effective clinical nomogram for predicting the survival of esophageal cancer patients after esophagectomy. We identified esophageal cancer patients (n = 4,281) who underwent esophagectomy between 1988 and 2007 from the Surveillance, Epidemiology, and End Results (SEER) 18 registries database. Clinically significant parameters for survival were used to construct a nomogram based on Cox regression analyses. The model was validated using bootstrap resampling and a Chinese cohort (n = 145). A total of 4,109 patients from the SEER database were included for analysis. The multivariate analyses showed that the factors of age, race, histology, tumor site, tumor size, grade and depth of invasion, and the numbers of metastases and retrieved nodes were independent prognostic factors. All of these factors were selected into the nomogram. The nomogram showed a clear prognostic superiority over the seventh AJCC-TNM classification (C-index: SEER cohort, 0.716 vs 0.693, respectively; P < 0.01; Chinese cohort, 0.699 vs 0.680, respectively; P < 0.01). Calibration of the nomogram predicted the probabilities of 3- and 5-year survival, which corresponded closely with the actual survival rates. This novel prognostic model may improve clinicians’ abilities to predict individualized survival and to make treatment recommendations.

Log Odds of Positive Lymph Nodes Predicts Survival in Patients After Resection for Esophageal Cancer

BACKGROUND

The number of lymph node metastases (LNMs) and the positive lymph node ratio (LNR) have been shown to be significant independent prognostic factors in predicting overall survival in patients with esophageal cancer. Our aim was to evaluate whether a novel prognostic indicator-the log odds of positive lymph nodes (LODDS)-predicts survival in esophageal cancer.

METHODS

Patients who underwent esophagectomy for esophageal cancer between 1988 and 2007 were identified from the Surveillance, Epidemiology, and End Results (SEER) database of 18 registries, and a Chinese patient cohort was subjected to validation. The prognostic efficacy of LNM, LNR, and LODDS was compared. Prognostic performance was measured using Harrell's C-index statistic, Schemper's proportion of explained variation, and the Akaike information criterion (AIC).

RESULTS

A total of 4,123 patients in the SEER database and 134 patients in the Chinese cohort met our criteria in this study. LODDS gave a better prognostic performance than either LNM or LNR in both the SEER database and the Chinese cohort. Multivariate analyses showed significant values for LNM, LNR, and LODDS as prognostic factors (p < 0.001). However, only LODDS was a significant prognostic factor regardless of the number of lymph nodes retrieved (p = 0.677). Furthermore, after stratification of patients with no nodes involved or all nodes involved, the values of LODDS still distinguished the heterogeneity efficiently.

CONCLUSIONS

LODDS predicts survival more accurately than either LNM or LNR in patients undergoing resection for esophageal cancer, especially for patients with an insufficient number of lymph nodes retrieved.

Lymph node ratio-based staging system for esophageal squamous cell carcinoma

AIM: To analyze a modified staging system utilizing lymph node ratio (LNR) in patients with esophageal squamous cell carcinoma (ESCC).

METHODS: Clinical data of 2011 patients with ESCC who underwent surgical resection alone between January 1995 and June 2010 at the Cancer Hospital of Shantou University Medical College were reviewed. The LNR, or node ratio (Nr) was defined as the ratio of metastatic LNs ompared to the total number of resected LNs. Overall survival between groups was compared with the log-rank test. The cutoff point of LNR was established by grouping patients with 10% increment in Nr, and then combining the neighborhood survival curves using the log-rank test. A new TNrM staging system, was constructed by replacing the American Joint Committee on Cancer (AJCC) N categories with the Nr categories in the new TNM staging system. The time-dependent receiver operating characteristic curves were used to evaluate the predictive performance of the seventh edition AJCC staging system and the TNrM staging system.

RESULTS: The median number of resected LNs was 12 (range: 4-44), and 25% and 75% interquartile rangeswere8 and 16. Patients were classified into four Nr categories with distinctive survival differences (Nr0: LNR = 0; Nr1: 0% < LNR ≤ 10%; Nr2: 10% < LNR ≤ 20%; and Nr3: LNR > 20%). From N categories to Nr categories, 557 patients changed their LN stage. The median survival time (MST) for the four Nr categories (Nr0-Nr3) was 155.0 mo, 39.0 mo, 28.0 mo, and 19.0 mo, respectively, and the 5-year overall survival was 61.1%, 41.1%, 33.0%, and 22.9%, respectively (P < 0.001). Overall survival was significantly different for the AJCC N categories when patients were subgrouped into 15 or more vs fewer than 15 examined nodes, except for the N3 category (P = 0.292). However, overall survival was similar when the patients in all four Nr categories were subgrouped into 15 or more vs fewer than 15 nodes. Using the time-dependent receiver operating characteristic, we found that the Nr category and TNrM stage had higher accuracy in predicting survival than the AJCC N category and TNM stage.

CONCLUSION: A staging system based on LNR may have better prognostic stratification of patients with ESCC than the current TNM system, especially for those undergoing limited lymphadenectomy.

Prognostic significance of lymph node ratio in esophageal cancer

N staging predicting esophageal cancer patient prognosis has been studied. Lymph node ratio, which is considered to show metastatic lymph node status more accurately, is found to have prognostic significance in several tumors. We investigated whether lymph node ratio (LNR) was associated with the prognosis of esophageal cancer in this study. Esophageal cancer patients who underwent esophagectomy at Qilu Hospital of Shandong University from January 2007 to December 2008 were studied. A total of 209 cases were evaluated in this study. The median disease-free survival (DFS) of this cohort was 35.2 months, and 5-year DFS rate was 32.1%. The median overall survival (OS) was 46.4 months, and 5-year OS rate was 40.0%. Kaplan-Meier survival analysis revealed that patients with LNR higher than 0.2 had significantly poorer DFS (p < 0.001) and OS (p < 0.001) than those with LNR less than 0.2. In a multivariate analysis, LNR was found to be an independent prognostic factor for DFS (p = 0.008, HR 1.863, 95% CI 1.180-2.942) and OS (p = 0.025, HR 1.708, 95% CI 1.068-2.731). N stage (p = 0.028, HR 1.626, 95% CI 1.055-2.506) was also found to be an independent prognostic factors for OS. Subgroups analysis revealed significant difference in OS and DFS rates between different LNR categories within the same N stages (p < 0.05) but not between different N stages within the same LNR category (p > 0.05). LNR was recognized as an independent factor in both OS and DFS in esophageal cancer. Besides, LNR showed a better prognostic value than N stage for esophageal cancer.