Modification of Nodal Categories in the Seventh American Joint Committee on Cancer Staging System for Esophageal Squamous Cell Carcinoma in Chinese Patients

Numeric pathologic lymph node classification shows prognostic superiority to topographic pN classification in esophageal squamous cell carcinoma

BACKGROUND

The current eighth tumor node metastasis lymph node category pathologic lymph node staging system for esophageal squamous cell carcinoma is based solely on the number of metastatic nodes and does not consider anatomic distribution. We aimed to assess the prognostic capability of the eighth tumor node metastasis pathologic lymph node staging system (numeric-based) compared with the 11th Japan Esophageal Society (topography-based) pathologic lymph node staging system in patients with esophageal squamous cell carcinoma.

METHODS

We retrospectively reviewed the clinical records of 289 patients with esophageal squamous cell carcinoma who underwent esophagectomy with extended lymph node dissection during the period from January 2006 through June 2016. We compared discrimination abilities for overall survival, recurrence-free survival, and cancer-specific survival between these 2 staging systems using C-statistics.

RESULTS

The median number of dissected and metastatic nodes was 61 (25% to 75% quartile range, 45 to 79) and 1 (25% to 75% quartile range, 0 to 3), respectively. The eighth tumor node metastasis pathologic lymph node staging system had a greater ability to accurately determine overall survival (C-statistics: tumor node metastasis classification, 0.69, 95% confidence interval, 0.62-0.76; Japan Esophageal Society classification; 0.65, 95% confidence interval, 0.58-0.71; P = .014) and cancer-specific survival (C-statistics: tumor node metastasis classification, 0.78, 95% confidence interval, 0.70-0.87; Japan Esophageal Society classification; 0.72, 95% confidence interval, 0.64-0.80; P = .018). Rates of total recurrence rose as the eighth tumor node metastasis pathologic lymph node stage increased, while stratification of patients according to the topography-based node classification system was not feasible.

CONCLUSION

Numeric nodal staging is an essential tool for stratifying the oncologic outcomes of patients with esophageal squamous cell carcinoma even in the cohort in which adequate numbers of lymph nodes were harvested.

Prognostic significance of lymph node metastasis in esophageal squamous cell carcinoma

Prediction of lymph node metastasis in esophageal squamous cell carcinoma (ESCC) is very important to have prognostic significance. The objective of this study which involved a relatively large number of ESCC patients was to investigate the correlated factors for lymph node metastasis and prognosis in ESCC. We analyzed a retrospective review of 446 patients with ESCC treated by esophagectomy between January 2010 and July 2016. The relationship between lymph node metastasis and clinicopathological parameters were analyzed. The association between overall survival and clinicopathological factors were evaluated using univariate and multivariable Cox regression models. In the present study, 36.8% esophageal squamous cell carcinoma patients were histologically shown to have lymph node metastasis. Lymph node metastasis was closely correlated with tumor differentiation (p=0.016), perineural invasion (p=0.022), advanced stage tumor (p<0.001) and venous invasion (p<0.001). Kaplan-Meier survival analysis revealed that patients with tumor size, higher T stage, perineuronal invasion, lymph node metastasis, N stage and LNR higher than 0.2 had unfavorable prognosis (p<0.05). The univariate analysis revealed for overall survival that tumor size, pathological stage, perineuronal invasion, lymph metastasis, N stage, involved LNR were relevant prognostic indicators. Furthermore, tumor size, lymph metastasis, N stage and LNR could as independent prognostic factors.

Proposed Modification of Nodal Staging as an Alternative to the Seventh Edition of the American Joint Committee on Cancer Tumor-Node-Metastasis Staging System Improves the Prognostic Prediction in the Resected Esophageal Squamous-Cell Carcinoma

INTRODUCTION

The 7th American Joint Committee on Cancer (AJCC) tumor-node-metastasis staging system for esophageal cancer defined N classification based on the number of metastatic lymph nodes (LNs). However, this classification might neglect the extent of LNs metastasis. This study aimed to revise N classification based on the extent of LNs metastasis and propose a modification to the current AJCC staging system for better representing the prognostic characteristics of Chinese esophageal squamous-cell carcinoma (ESCC).

METHODS

We retrospectively reviewed 1993 ESCC patients who underwent curative resection. The proposed N categories based on the number of LNs metastasis stations were compared with the current staging system by univariate and multivariate Cox regression analyses. Homogeneity, discriminatory ability, and monotonicity of gradients of two staging systems were compared using likelihood ratio χ statistics and Akaike information criterion calculations.

RESULTS

The survival differences were not significant for N2 versus N3 category (p = 0.231) and stages IIIB versus IIIC (p = 0.713) based on the 7th AJCC staging system. When the modified staging system was adopted, the survival difference for N2 versus N3 and IIIB versus IIIC could be well discriminated. Statistical analysis showed that the modified staging system had higher likelihood ratio χ scores and smaller Akaike information criterion values than the 7th AJCC staging system, which represented the optimum prognostic stratification.

CONCLUSIONS

The modified staging system with the revised N categories based on the number of LNs metastasis stations better predicts the survival of Chinese ESCC population than the 7th AJCC staging system. Further studies are required to confirm this result.

Time distribution of recurrence risk of oesophageal squamous cell carcinoma with complete resection (R0) in a Chinese population

OBJECTIVES

We aimed to clarify the correlation between clinic-pathological characteristics and the distribution of recurrence probability during follow-up of oesophageal squamous cell carcinoma (OSCC) patients with complete resection analysis by hazard function, and to try to provide evidence-based data for optimal timing for adjuvant therapy.

METHODS

A single-institution, retrospective study was conducted on 553 Chinese patients with OSCC who underwent R0 resection between January 2005 and October 2007. Survival curves were generated using the Kaplan-Meier method, and hazard function was used to analyse the annual recurrence hazard.

RESULTS

The median recurrence-free survival time of these patients was 3.4 years. In univariate analysis, the favourable prognostic factors were gender, smoking status, a tumour length of ≤4.0 cm, tumour invasion thickness, normal level of squamous cell carcinoma (SCC) antigen, pathological T category and pathological N category. In multivariate analysis, pathological T category and pathological N category were independent prognostic factors. Overall, the recurrence hazard curve for the entire cohort showed that the first major recurrence surge began to increase from the first year at 22.97% and peaked at 1.3 years at 27.4% during follow-up. The second recurrence surge peaked during the seventh year at 13.0%. A lower recurrence risk was observed in patients with the following clinic-pathological characteristics: gender, smoking status and N0.

CONCLUSIONS

We identify the presence of two peaks for recurrence risk in Chinese patients with resectable OSCC, which might contribute to choosing the optimal timing for adjuvant therapy after an operation to decrease or delay the recurrence hazard for patients with resectable OSCC.

The impact of tumor cell differentiation on survival of patients with resectable esophageal squamous cell carcinomas

BACKGROUND

The current American Joint Committee on Cancer staging system considers tumor cell differentiation grade to be a factor in the staging of esophageal squamous cell carcinoma (ESCC) in pathologic T0-3N0M0 cases. However, more data are essential to test its efficacy. We sought to investigate the tumor-node-metastasis categories for which tumor cell grade might affect overall survival in Chinese patients.

METHODS

We conducted a retrospective review of 1,220 patients with ESCC who underwent complete resection between December 1996 and December 2008. Survival was calculated by the Kaplan-Meier method, and the log-rank test was used to assess differences in survival between groups. Subgroup analyses and the Cox proportional hazards model were used to further determine the effect of tumor cell grade on overall survival.

RESULTS

The 5-year survival rates for the G1, G2, and G3 groups of pathologic T2N0M0 ESCC cases were 80.1, 61.9, and 47.4%, respectively (p = 0.015), and these rates in the pathologic T3N0M0 ESCC cases were 66.7, 61.7, and 41.2%, respectively (p = 0.020). However, the differences in the survival of the different tumor cell grade groups of the pathologic T1N0M0 (p = 0.198) and the node positive categories (p = 0.063) were not statistically significant. Multivariate Cox regression analysis confirmed that tumor cell grade independently affected the overall survival of patients with pathologic T2-3N0M0 ESCC.

CONCLUSIONS

The staging of ESCC in the Chinese population should be simplified by omitting tumor cell grade as a variable in patients with pathologic T1N0M0 disease. More data are needed to verify our results.

Proposed modification of the seventh American Joint Committee on Cancer staging system for esophageal squamous cell carcinoma in Chinese patients

BACKGROUND

More data are essential to test the efficacy of the American Joint Committee on Cancer (AJCC) system for staging esophageal squamous cell carcinoma (ESCC). On the basis of previous studies, we propose a modification to this system to better represent the survival characteristics of ESCC in the Chinese population.

METHODS

We used data from two centers to establish the generating (n = 1006) and validation (n = 783) cohorts. All of the patients underwent curative surgical treatment. On the basis of previous studies, we excluded tumor location as a variable in the modified pathological staging system and defined the modified nodal categories as follows: N0, node negative; N1, 1 positive node; N2, 2 to 3 positive nodes; and N3, >3 positive nodes. The pathological T categories, pathological M categories, and cell differentiation in the seventh AJCC staging system for adenocarcinoma were used in the modified pathological staging system for ESCC.

RESULTS

The median survival times for ESCC patients with stage 0 and Ia, stage Ib, stage IIa, stage IIb, stage IIIa, stage IIIb, stage IIIc were as follows: not reached, 221.2, 151.8, 88.5, 25.0, 19.0, and 13.0 months, respectively, for the entire cohort of patients (n = 1789). The corresponding 5-year survival rates were 86.7, 76.4, 64.9, 55.3, 29.9, 16.9, and 9.7 %, respectively. The survival rates significantly differed between the modified staging groups (p < 0.01).

CONCLUSIONS

This modified staging system better discriminates the survival differences between stages than the seventh edition of the AJCC staging system for ESCC in Chinese patients.

Use of the metastatic lymph node ratio to evaluate the prognosis of esophageal cancer patients with node metastasis following radical esophagectomy

Objectives

The objective of this study was to investigate the number of metastatic lymph nodes (pN) and the metastatic lymph node ratio (MLR) on the post-surgical prognosis of Chinese patients with esophageal cancer (EC) and lymph node metastasis.

Methods

We enrolled 353 patients who received primary curative resection for EC from 1990 to 2003. The association of pN and MLR with 5-year overall survival (OS) was examined by receiver operating characteristic (ROC) and area under the curve (AUC) analysis. The Kaplan-Meier method was used to calculate survival rates, and survival curves were compared with the log-rank test. The Cox model was employed for univariate and multivariate analyses of factors associated with 5-year OS.

Results

The median follow-up time was 41 months, and the 1-, 3- and 5-year OS rates were 71.2%, 30.4%, and 19.5%, respectively. Univariate analysis showed that age, pN stage, and the MLR were prognostic factors for OS. Patients with MLRs less than 0.15, MLRs of 0.15-0.30, and MLRs greater than 0.30 had 5-year OS rates of 30.1%, 17.8%, and 9.5%, respectively (p < 0.001). Patients classified as pN1, pN2, and pN3 had 5-year OS rates of 23.7%, 11.4%, and 9.9%, respectively (p < 0.001). Multivariate analysis indicated that a high MLR and advanced age were significant and independent risk factors for poor OS. Patients classified as pN2 had significantly worse OS than those classified as pN1 (p = 0.022), but those classified as pN3 had similar OS as those classified as pN1 (p = 0.166). ROC analysis indicated that MLR (AUC = 0.585, p = 0.016) had better predictive value than pN (AUC = 0.565, p = 0.068).

Conclusions

The integrated use of MLR and pN may be suitable for evaluation of OS in Chinese patients with EC and positive nodal metastasis after curative resection.

Prognostic factors and outcome for patients with esophageal squamous cell carcinoma underwent surgical resection alone: evaluation of the seventh edition of the American Joint Committee on Cancer staging system for esophageal squamous cell carcinoma

INTRODUCTION

More data are essential to test the efficacy of the seventh edition of the American Joint Committee on Cancer (AJCC) staging system for esophageal squamous cell carcinoma (ESCC). This retrospective study was designed to identify the prognostic factors for survival of patients with ESCC who underwent surgical resection alone and to evaluate the new AJCC staging system for ESCC.

METHODS

Data of a single-center cohort of 2011 patients with ESCC who underwent surgical resection alone according to the new staging system were reviewed. Univariate and multivariate analyses were performed to identify prognostic factors.

RESULTS

The 1-, 3-, and 5-year overall survival rates were 83.5, 57.4, and 47.4%, respectively, with a median survival time of 51.0 months. Age, histologic grade, R-category, pT category, pN category, pM category, pTNM stage, and the extent of lymph node metastasis were independent prognostic factors (p < 0.05). In separate subgroup analyses, the survival differences were not significant for pN2 versus pN3 category (p = 0.159) and stages IA versus IB (p = 0.922). Subdivisions by depth of infiltration rather than tumor grade for pT1N0M0 cancers and modified nodal categories (0, 1, 2-3, and ≥4 positive lymph nodes) better represented a survival advantage.

CONCLUSIONS

The seventh edition of the AJCC staging system for ESCC is acceptable in predicting survival. However, tumor location does not influence survival in our study. Subdivisions of pT1N0M0 cancers and the N-classification may need to be modified.

Impact of esophageal cancer staging on overall survival and disease-free survival based on the 2010 AJCC classification by lymph nodes

This retrospective study investigated the effect of modifications presented in the seventh edition of the American Joint Committee on Cancer (AJCC) Manual for staging esophageal cancer on the characterization of the effectiveness of post-operative chemotherapy and/or radiotherapy, as measured by overall and disease-free survival. The seventh edition of the AJCC Manual classifies the number of lymph nodes (N) positive for regional metastasis into three subclasses. We used the AJCC classification system to characterize the cancers of 413 Chinese patients with esophageal cancer who underwent radical resection plus regional lymph node dissection over a 10-year period. The 10-year survival rate was 14.3% for stage N1 patients and 6.1% for stage N2 patients. Only one stage N3 patient was followed >4 years (53.4 months). The 10-year disease-free rate was 13.6% for stage N1 patients. Patients with stage N2 or N3 cancer were more likely to have tumor recurrences, metastases or death than patients with stage N1 cancer. Post-operative radiotherapy provided no survival benefit, and may have had a negative effect on survival. In this study, the N stage of esophageal cancer was an independent factor affecting overall and disease-free survival. Our results did not clarify whether or not radiotherapy after radical esophagectomy offers any survival benefit to patients with esophageal cancer.

The positive lymph node ratio predicts long-term survival in patients with operable thoracic esophageal squamous cell carcinoma in China

BACKGROUND

Controversy exists concerning the optimal cutoff points for the positive lymph node ratio (PLNR) to predict overall survival. We aim to propose reasonable PLNR categories for the discrimination of the survival difference between groups.

METHODS

We used data from two centers to establish a training (n = 1006) and a validation (n = 783) cohort. All of the patients underwent curative surgical treatment. Martingale residuals from a Cox proportional hazards regression model were used to determine the optimal cutoff points for PLNR to predict overall survival. The survival rate was calculated using the Kaplan-Meier method, and a log-rank test was used to assess the survival differences between groups. The results obtained from the training cohort were tested with the validation cohort at each step.

RESULTS

We classified the patients into four revised nodal categories: R-pN0 (PLNR = 0), R-pN1 (0< PLNR ≤0.1), R-pN2 (0.1< PLNR ≤0.3), and R-pN3 (PLNR >0.3). Subgroup analysis for the pT2 and pT3 cases showed that the survival differences could be well discriminated between groups based on PLNR in both the training cohort and validation cohort. When we modified the current staging system using revised nodal categories (based on PLNR) instead of the AJCC nodal categories, the survival rate could also be easily distinguished between patients in different stages in both cohorts of patients.

CONCLUSIONS

The survival rate of ESCC can be discriminated between four groups: PLNR = 0, 0< PLNR ≤0.1, 0.1< PLNR ≤0.3, and PLNR >0.3. Further studies are required to confirm these results.