Nodal Skip Metastasis in Esophageal Squamous Cell Carcinoma Patients Undergoing Three-Field Lymphadenectomy

Comparison of TNM AJCC/UICC 8th with JES 11th staging systems for prognostic prediction in patients with esophageal squamous cell carcinoma who underwent radical (chemo) radiotherapy in China

OBJECTIVE

The aim of the study was to compare the prognostic prediction performances of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) 8th staging system and the Japan Esophageal Society (JES) 11th staging system for patients with esophageal squamous cell carcinoma who underwent radical (chemo) radiotherapy.

METHODS

In total, 574 patients were enrolled and categorized according to the tumor, node metastasis (TNM) AJCC/UICC 8th and JES 11th editions. Survival rates and disease-free survival were computed using the Kaplan-Meier technique. The log-rank test was used for survival difference analysis.

RESULTS

(1) The 8th AJCC/UICC N staging exhibited significant stratification for overall survival (OS) and progression-free survival (PFS). JES 11th showed significant OS stratification, but PFS was not well-stratified for N2-N4. (2) Both staging systems demonstrated significant stratification for OS and PFS. (3) AJCC/UICC 8th TNM staging yielded significantly well-stratified OS and PFS in the differing staging group. JES 11th failed to stratify OS and PFS for stages III and IVA. (4) AJCC/UICC 8th TNM stratified OS and PFS significantly well for lower and middle region tumors, whereas JES 11th inadequately stratified stages III and IVA. (5) Significant multivariable analysis results indicated that AJCC/UICC 8th independently predicted poor OS and PFS.

CONCLUSIONS

In Chinese patients with esophageal squamous cell carcinoma who underwent radical (chemo) radiotherapy, the AJCC/UICC 8th edition exhibited superior prognostic prediction capabilities compared with the JES 11th edition.

The prognostic value of 11th Japanese classification and 8th AJCC staging systems in Chinese patients with esophageal squamous cell carcinoma

BACKGROUND

Two staging systems, the 8th staging system by the American Joint Committee on Cancer (AJCC) and the 11th Japanese classification by Japan Esophageal Society (JES), are currently applied in the clinic for predicting the prognosis of patients with esophageal squamous cell carcinoma (ESCC). The differences between the two staging systems have been widely researched. However, little studies focus on the differences in specific staging between the two systems. Therefore, we aimed to compare the performance of different staging in predicting overall survival (OS) of Chinese patients with ESCC.

METHODS

This retrospective study included 268 patients who underwent radical esophagectomy and mediastinal lymph node dissection for ESCC between January 2008 and December 2013. Patients were staged by the 8th AJCC and 11th JES staging systems. OS was estimated using the Kaplan-Meier method and compared between N stages and between stage groupings using the log-rank test. Cox proportional hazards regression analysis was performed to identify factors independently related to outcome. Further, we compared the concordance indexes (C-indexes) of the two staging systems.

RESULTS

The mean age was 61.25 ± 7.056 years, median follow-up was 44.82 months, and 5-year OS rate was 47%. The OS was well predicted by the 8th AJCC N staging (P < 0.001) and the 11th JES N staging (P < 0.001), with a c-index of 0.638 (95% CI: 0.592-0.683) for AJCC N staging and 0.627 (95% CI: 0.583-0.670) for JES N staging (P = 0.13). In addition, the OS was also well predicted by stage groupings of the 8th AJCC (P < 0.001) and the 11th JES systems (P < 0.001), with a c-index of 0.658 (95% CI: 0.616-0.699) for 8th AJCC stage grouping and 0.629 (95% CI: 0.589-0.668) for the11th JES stage grouping (P = 0.211).

CONCLUSIONS

The prognostic effect of 11th JES staging system is comparable with that of AJCC 8th staging system for patients with ESCC. Therefore, both systems are applicable to clinical practice.

The Prognostic Value of Nodal Skip Metastasis in Patients with Esophageal Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Esophageal cancer (EC) is the sixth leading cause of cancer deaths worldwide. Nodal skip metastasis (NSM), a common form of lymphatic spread in EC, can be defined as the metastatic involvement of distant lymph nodes (LNs) without prior involvement of adjacent LNs. The results of the previous studies investigating the association between NSM and survival outcomes in patients with EC were inconsistent and even contradictory. The aim of this systematic review and meta-analysis is to investigate the prognostic value of NSM and to summarize the NSM definitions of EC in previous studies.

METHODS

Four databases were used in this meta-analysis. The association between NSM and overall survival (OS) was evaluated by using pooled HRs and their 95% confidence interval (CI). The sensitivity analysis and funnel plot were used to assess the publication bias.

RESULTS

Nine studies were included in this meta-analysis. The pooled results of meta-analysis indicated that there was no significant association between NSM and OS (HR = 0.99, 95% CI: 0.75-1.31; P = 0.951). Meanwhile, according to the results of sub-group analysis on the basis of histological feature, method of lymphadenectomy, node staging system, and NSM definitions, no significant association was found between NSM and OS.

CONCLUSIONS

On the basis of available evidences, NSM could not be used as a prognostic factor for patients with EC. For future studies investigating the prognostic value of NSM, only three-field lymphadenectomy with adequate harvested LNs can be performed. NSM definitions based on lymph node station and anatomical compartment could both be feasible classification for EC.

Relationship between postoperative nodal skip metastasis of mid-thoracic esophageal squamous cell carcinoma and patient prognosis and its value in guiding postoperative adjuvant treatment

Objective

To evaluate the predictive role of nodal skip metastasis (NSM) in the prognosis of lymph node-positive mid-thoracic esophageal squamous cell carcinoma, and to evaluate the significance of postoperative adjuvant treatment in patients with different sites of metastatic nodes.

Methods

A retrospective analysis was performed on clinical data of 321 lymph node-positive mid-thoracic esophageal squamous cell carcinoma patients who underwent surgery in the Fourth Hospital of Hebei Medical University. Based on the site and condition of lymph node metastasis by postoperative pathology, the patients were divided into two groups: NSM group and non-NSM (NNSM) group. The propensity score matching (PSM) method was employed to match the two groups. The prognostic factors of patients before and after PSM as well as the effect of different adjuvant treatment modes on the prognosis of patients before and after PSM were analyzed. SPSS 29.0 statistical software was used for analysis.

Results

PSM in a 1 : 1 matching ratio was performed, 103 patients were assigned to NSM group and NNSM group respectively. Significant differences were found in the 3- and 5-year OS and DFS between the two groups before PSM, the 3- and 5-year OS also showed a significant difference after PSM (P < 0.05). Multivariate analysis illustrated that gender, postoperative adjuvant treatment mode, N stage and lymph node metastasis were independent risk factors for OS and DFS after PSM (P < 0.05); for NSM patients, postoperative adjuvant chemotherapy and radiotherapy significantly prolonged OS and DFS before and after PSM (P < 0.05). But no significant difference was found in OS and DFS for NNSM patients after PSM (P > 0.05).

Conclusion

Postoperative NSM is a good prognostic factor for patients with mid-thoracic esophageal squamous cell carcinoma, postoperative adjuvant chemoradiotherapy was recommended for those group, thereby gaining survival benefits.

Prognostic value of node skip metastasis on esophageal cancer: A systematic review and meta-analysis

The association between NSM and prognosis of esophageal cancer remains controversial, though several studies have been conducted drawing their own conclusion. Therefore, we firstly carried out this meta-analysis aiming to explore the association. We performed a comprehensive literature search online, including PubMed, Embase and Web of Science. We selected deaths at 5 years and hazard ratio (HR) with 95% (CI) to perform the meta-analysis with Review Manager 5.3, predicting value of clinic-pathological features in NSM also been analyzed. A total of 7 studies were finally enrolled in this study. NSM, defined by either JSED criterion or anatomical compartment criterion, neither showed significant prognostic value on OS of esophageal cancer (P = 0.64), (P = 0.24). Subgroup analysis of JSED criterion, NSM was not a prognostic factor in solitary node metastasis patients (P = 0.39), whereas NSM demonstrated a poor prognostic factor (P = 0.01) for ESCC. Subgroup analysis according to anatomical criterion, NSM was a favorable factor for OS in middle thoracic ESCC (P = 0.003). Pathological N1 status was found to be a risk factor for NSM (P < 0.00001) according to JSED criterion and middle thoracic ESCC was identified as a predictor for NSM (P = 0.0003) according to anatomical compartment criterion. According to JSED criterion, NSM demonstrated poor prognosis on ESCC and N1 status was a risk factor for NSM. Concerning the anatomical compartment criterion, a favorable prognosis of NSM was found in middle thoracic ESCC and NSM was prone to occur in middle thoracic ESCC. CRD42021219333.

Role of nodal skip metastasis in patients with mid-thoracic oesophageal squamous cell carcinoma: a propensity score matching study

OBJECTIVES

Nodal skip metastasis (NSM) is a common phenomenon in mid-thoracic oesophageal squamous cell carcinoma (MT-OSCC); however, the prognostic implications of NSM in patients with MT-OSCC remain unclear.

METHODS

This retrospective study enrolled 300 patients with MT-OSCC who underwent radical oesophagectomy and who had pathologically confirmed lymph node metastasis from January 2014 to December 2016. The patients were divided into 2 groups according to the presence or absence of NSM. Propensity score matching was applied to minimize patient selection bias. The impact of NSM on overall survival (OS) was assessed by Kaplan-Meier and multiple Cox proportional hazards analyses. The median follow-up time was 57 months.

RESULTS

The NSM rate in the entire cohort was 22.0% (66/300). Pathological N (pN) stage (P < 0.001) and sex (P = 0.001) were identified as significant independent risk factors for NSM. NSM was more frequent in pN1 compared with pN2 patients (87.9% vs 12.1%, P < 0.001) and no NSM was found in pN3. NSM(+) patients had better prognoses than NSM(-) patients (Kaplan-Meier; 3-year OS, 62.1% vs 34.1%, P < 0.001). Propensity score matching produced 51 matched pairs, and the 3-year OS was still better in the NSM(+) compared with the NSM(-) group (66.7% vs 40.0%, P = 0.025). Multivariable Cox analysis confirmed NSM(+) as an independent factor favouring OS in patients with MT-OSCC.

CONCLUSIONS

NSM usually occurs at pN1 stage in patients with MT-OSCC, and is associated with a favourable prognosis.

Thoracoscopic radical esophagectomy combined with left inferior pulmonary ligament lymphadenectomy for esophageal carcinoma via the right thoracic approach: A single-center retrospective study of 30 cases

To evaluate the necessity, safety, and feasibility of left inferior pulmonary ligament lymphadenectomy during video-assisted thoracic surgery (VATS) radical esophagectomy via the right thoracic approach.Thirty patients (20 men, 10 women) with thoracic esophageal squamous cell carcinoma (ESCC) were recruited for this study. The patients' age ranged from 50 to 80 years, with an average age of 66.17 ± 7.47 years. After the patients underwent VATS radical esophagectomy and left inferior pulmonary ligament lymph node dissection (LIPLND) via the right thoracic approach, the operative outcomes included operative time, length of hospital stay, postoperative complications, number of lymph nodes removed, and postoperative pathologic results were evaluated.There were no massive hemorrhages of the left inferior pulmonary vein during the operation. The operative time of LIPLND was 8.67 ± 2.04 minutes, and the length of postoperative hospital stay was 12.23 ± 2.36 days. The postoperative complications included 2 cases of left pneumothorax, 4 pulmonary infection cases, and no chylothorax. Moreover, 68 LIPLNs were dissected, 5 of which were positive, and the degree of metastasis was 7.4%. The postoperative pathologic results showed that 3 cases of LIPLNs were positive, with a metastasis rate of 10.0%. Among them, 2 cases were SCC of the lower thoracic esophagus, and 1 case was SCC of the middle thoracic esophagus, which involved the lower segment.Thoracoscopic esophagectomy combined with left inferior pulmonary ligament lymphadenectomy for esophageal carcinoma via the right thoracic approach will not increase the difficulty of operation, increase the incidence of postoperative complications or prolong the postoperative hospital stay, and can theoretically reduce tumor recurrence. Therefore, we believe that LIPLND is necessary, safe, and feasible and is worthy of clinical popularization and application.

Prognostic Role of Nodal Skip Metastasis in Thoracic Esophageal Squamous Cell Carcinoma: A Large-Scale Multicenter Study

BACKGROUND

Nodal-skip metastasis (NSM) is found in esophageal squamous cell carcinoma (ESCC), but its prognostic role is controversial. This study aimed to investigate the prognostic value of NSM for thoracic ESCC patients.

METHODS

Categorization of NSM was according to the N groupings of Japan Esophagus Society (JES) staging system, which is dependent on tumor location. Using the Kaplan-Meier method and Cox-regression analysis, this study retrospectively analyzed the overall survival (OS) for 2325 ESCC patients after radical esophagectomy at three high-volume esophageal cancer centers. Predictive models also were constructed.

RESULTS

The overall NSM rate was 20% (229/1141): 37.4% in the in upper, 12.9% in the middle, and 22.2% in the lower thoracic ESCC. The patients with NSM always had a better prognosis than those without NSM. Furthermore, NSM was an independent prognostic factor for thoracic ESCC patients (hazard ratio [HR], 0.633; 95% confidence interval [CI], 0.499-0.803; P < 0.001). By integrating the prognostic values of NSM and N stage, the authors proposed the new N staging system. The categories defined by the new N staging system were more homogeneous in terms of OS than those defined by the current N system. Moreover, the new N system was shown to be an independent prognostic factor also for thoracic ESCC patients (HR, 1.607; 95% CI, 1.520-1.700; P < 0.001). Overall, the new N system had slightly better homogeneity, discriminatory ability, and monotonicity of gradient than the current N system.

CONCLUSIONS

This study emphasized the prognostic power of NSM and developed a modified node-staging system to improve the efficiency of the current International Union for Cancer Control (UICC)/American Joint Committee on Cancer (AJCC) N staging system.

Impact of treatment modality on long-term survival of stage IA small-cell lung cancer patients: a cohort study of the U.S. SEER database

Background

The optimal treatment modality for patients with stage IA (T1N0M0) small-cell lung cancer (SCLC) is still unclear.

Methods

Patients who received surgical resection or chemo-radiotherapy (CRT) between January 2004 and December 2014 were identified from The Surveillance, Epidemiology and End Results (SEER) database. Surgical resection included lobectomy, wedge resection, segmentectomy with lymphadenectomy [examined lymph node (ELN) ≥1]. Propensity score match analysis was utilized to balance the baseline characteristics.

Results

A total of 686 stage IA SCLC cases were included: 337 patients underwent surgery and 349 patients were treated by CRT alone. Surgery achieved a better outcome than CRT alone, with an adjusted hazard ratio (HR) of 0.495. Patients who underwent lobectomy demonstrated a longer overall survival (OS), compared to those who received sublobectomy (crude cohort, median OS, 69 vs. 38 months; match cohort, median OS, 67 vs. 38 months). Patients with ELN >7 presented with longer OS than those with ELN ≤7 (crude cohort, median OS, 91 vs. 49 months; matched cohort, median OS, 91 vs. 54 months). The additional efficacy of chemotherapy or radiotherapy in patients receiving lobectomy was observed. The best prognosis was achieved in the lobectomy plus CRT cohort, with a 5-year survival rate of 73.5%.

Conclusions

The prolonged survival associated with lobectomy and chemotherapy or radiotherapy presents a viable treatment option in the management of patients with stage IA SCLC.

Distribution of Lymph Node Metastases in Esophageal Carcinoma Patients Undergoing Upfront Surgery: A Systematic Review

Metastatic lymphatic mapping in esophageal cancer is important to determine the optimal extent of the radiation field in case of neoadjuvant chemoradiotherapy and lymphadenectomy when esophagectomy is indicated. The objective of this review is to identify the distribution pattern of metastatic lymphatic spread in relation to histology, tumor location, and T-stage in patients with esophageal cancer. Embase and Medline databases were searched by two independent researchers. Studies were included if published before July 2019 and if a transthoracic esophagectomy with a complete 2- or 3-field lymphadenectomy was performed without neoadjuvant therapy. The prevalence of lymph node metastases was described per histologic subtype and primary tumor location. Fourteen studies were included in this review with a total of 8952 patients. We found that both squamous cell carcinoma and adenocarcinoma metastasize to cervical, thoracic, and abdominal lymph node stations, regardless of the primary tumor location. In patients with an upper, middle, and lower thoracic squamous cell carcinoma, the lymph nodes along the right recurrent nerve are often affected (34%, 24% and 10%, respectively). Few studies describe the metastatic pattern of adenocarcinoma. The current literature is heterogeneous in the classification and reporting of lymph node metastases. This complicates evidence-based strategies in neoadjuvant and surgical treatment.

Clinical significance and prognosis of supraclavicular lymph node metastasis in patients with thoracic esophageal cancer

Background

Although most studies proved that thoracic esophageal cancer surgery with supraclavicular lymph nodes (SCLNs) metastasis could benefit, less than 30% of the 5-year survival rate remained controversy on its surgical treatment. In this study, we aimed to analyze the prognosis of SCLNs on the different segments of thoracic esophageal cancer, which will supply a reference for the treatment of this disease.

Methods

Retrospectively collected the clinical data of 163 patients with thoracic esophageal squamous cancer (ESCC) and compared the effects of SCLNs on prognosis in different segments.

Results

Patients with SCLNs metastasis had a worse prognosis than the negative group (P<0.001). In the upper thoracic group, there was no significant difference in OS between SCLNs positive group and negative group (P=0.077); however, in the middle and lower thoracic group, SCLNs positive group had a worse prognosis than the negative group (P<0.001) and lymph nodes positive in other sites (except for SCLNs) (P=0.039). Multivariate analysis found that SCLNs metastasis was an independent risk factor affecting the prognosis of ESCC in the middle and lower thoracic segments (P=0.007).

Conclusions

For patients with upper thoracic ESCC, SCLNs appear to be regional nodes. For the middle and lower thoracic ESCC, SCLNs should be defined as distant metastasis, and neoadjuvant therapy first may be an available therapy.

Should the clinical significance of supraclavicular and celiac lymph node metastasis in thoracic esophageal cancer be reevaluated?

Background

Lower thoracic esophageal cancer (LTEC) with celiac node metastasis and upper thoracic esophageal cancer (UTEC) with supraclavicular node metastasis were previously categorized as M1a diseases. Our study aimed to investigate whether the clinical significance of supraclavicular and celiac lymph node metastasis should be reevaluated in thoracic esophageal cancer.

Methods

A total of 6178 patients with thoracic esophageal cancer were identified from the Surveillance, Epidemiology, and End Results (SEER) database during 2004–2015. Treatment strategies and outcomes (OS, overall survival; CSS, cancer‐specific survival) of patients with different nodal status were reviewed. The Cox proportional hazards regression model was applied to evaluate the prognostic factors. Statistical analyses were performed in all subgroups.

Results

Multivariate analysis identified supraclavicular node metastasis but not celiac node metastasis as an independent predictor of both OS and CSS in LTEC. However, metastasis to supraclavicular or celiac nodes was not an independent predictor of OS and CSS in UTEC. Surgery was not associated with increased OS and CSS for UTEC with celiac or supraclavicular node metastasis but was favored as a predictor of better OS and CSS for LTEC with celiac or supraclavicular node metastasis. Radiotherapy benefited OS and CSS in LTEC involving celiac or supraclavicular nodes and in UTEC involving celiac nodes, while only OS benefited from radiotherapy in UTEC involving supraclavicular nodes.

Conclusions

These results provide preliminary evidence that the clinical significance of supraclavicular and celiac lymph node metastasis should be reevaluated in thoracic esophageal cancer with different prognostic information according to the primary sites.

Histone deacetylase 6 expression in metastatic lymph nodes is a valuable prognostic marker for resected node-positive esophageal squamous cell cancer

Background

Histone deacetylase 6 (HDAC6) exerts enzymatic deacetylation activity on histones and on non-histone substrates and plays a key role in microtubule dynamics and chaperone activities. In addition, previous studies have demonstrated its role in cancer progression. However, its clinical significance in esophageal squamous cell cancer (ESCC) has not been elucidated. We investigated the correlation of HDAC6 expression and clinical outcome in a group of T3N1–3M0 surgically resected ESCCs.

Methods

Tissue microarrays were conducted on 209 surgically resected T3N1–3M0 ESCC tumors, including 163 pairs of primary tumors (PTs) and their corresponding metastatic lymph nodes (MLNs). Immunohistochemistry was utilized to evaluate HDAC6 protein levels. The relationship between patient outcomes and HDAC6 expression was analyzed statistically.

Results

The level of HDAC6 expression in ESCC MLNs was found to be significantly lower than that in PTs (P<0.001). Patients with lower MLN HDAC6 expression demonstrated improved overall survival (P=0.011) and disease-free survival (P=0.012) than those with higher HDAC6 expression. HDAC6 expression levels in PTs revealed no prognostic significance. Multivariate analysis showed that the MLN HDAC6 expression level was an independent prognostic factor for both overall survival (HR 1.456, P=0.029) and disease-free survival (HR 1.432, P=0.033).

Conclusion

High expression of HDAC6 in MLNs but not in PTs suggests a poor prognosis for patients with resected T3N1–3M0 ESCC. We should take into account the protein expression of MLNs when assessing prognosis in patients with lymph-node involvement.

Predicting prognosis in resected esophageal squamous cell carcinoma using a clinical nomogram and recursive partitioning analysis

BACKGROUND

Development demand of precise medicine in resectable esophageal squamous cell carcinoma (ESCC) require to recognize patients at high risk treated by surgery alone. Thus, our aim was to construct a clinical nomogram and recursive partitioning analysis (RPA) to predict long-term survival in ESCC treated by surgery alone.

METHODS

Based on the patients with ESCC who treated by three-incisional esophagectomy and two-field lymphadenectomy alone, we identified and integrated significant prognostic factors for survival to build a nomogram. The nomogram was calibrated for overall survival (OS) and the predictive accuracy and discriminative ability was measured by concordance index (c-index) and Akaike information criterion (AIC). Based on the nomogram, the RPA was performed for risk stratification.

RESULTS

A total of 747 patients were included for analysis. Five independent prognostic factors were identified and entered into the nomogram. The calibration curves for probability of 1-, 3-, and 5-year OS showed optimal agreement between nomogram prediction and actual observation. The AIC value of the nomogram was lower than that of the 7th edition staging system, whereas the c-index of the nomogram was higher than that of the 7th edition staging system. The risk groups stratified by RPA allowed significant distinction between survival curves within respective TNM categories.

CONCLUSION

The RPA based on a clinical nomogram appears to be suitable for risk stratification in OS for resected ESCC. This practical system may help clinicians in decision making and design of clinical studies.

Elucidation of the Anatomical Mechanism of Nodal Skip Metastasis in Superficial Thoracic Esophageal Squamous Cell Carcinoma

Background

Lymph node metastasis (LNM) is a standard mechanism of cancer progression in esophageal squamous cell carcinoma (ESCC). We aimed to clarify the anatomical mechanism of skip nodal metastasis to mediastinal zones by analyzing the relationship between LNM to sentinel zones and lymphatic vessel counts in the muscle layer adjacent to the outer esophagus.

Methods

We examined the surgical records of 287 patients with ESCC who underwent potentially curative surgery (three-field lymphadenectomy) and whole esophagi, including pharynges and stomachs from 10 cadavers, to determine the number of lymphatic vessels in the intra-outer longitudinal muscle layer adjacent to the outer esophagus of the cervical (Ce), upper thoracic, middle thoracic (Mt), lower thoracic (Lt), and abdominal esophagi (Ae).

Results

The frequency of LNM to the middle mediastinal and supraclavicular zones, including the Mt and Ce, respectively, was lower than to the upper and lower mediastinal and abdominal zone in patients with superficial and advanced thoracic ESCC. In cadavers, the lymphatic vessel counts of the intra-outer longitudinal muscle layer in the Mt and Ce were significantly lower than those of the Lt and Ae, suggesting that lymphatic flow toward the outside of the Mt and Ce was not more abundant than to other sites.

Conclusion

Our anatomical data suggested that the absence of intra-muscle lymphatic vessels in the middle mediastinal and supraclavicular zones causes skip LNM in patients with thoracic ESCC. Thus, standard esophagectomy with lymph node dissection, including distant zones, may be appropriate for treating patients with superficial thoracic ESCC.

Electronic supplementary material

The online version of this article (10.1245/s10434-018-6390-0) contains supplementary material, which is available to authorized users.

Comparison of two major staging systems of esophageal cancer-toward more practical common scale for tumor staging

The latest 8th edition of TNM Classification of Malignant Tumours by Union for International Cancer Control (UICC) and 11th edition of Japanese Classification of Esophageal Cancer by Japan Esophageal Society (JES) are the two major classifications widely accepted as tools for clinical staging of esophageal cancer. Both systems consist of three main categories, i.e., T, N, and M, but large difference exists between the two. JES system has more detailed sub-classification of T1 tumors reflecting meticulous work by Japanese investigators on superficial esophageal cancer. N-category shows the largest difference. UICC defines the N-category according to only the number of the metastatic regional lymph nodes. The definition of regional nodes in UICC system is static and uniform, and supraclavicular nodes are definitely excluded. In JES system, regional nodes are subgrouped into five different patterns according to the main tumor location, and the supraclavicular nodes are always regional nodes for thoracic esophageal cancer. Japanese surgeons have described the evidence that regional nodes should be dynamically defined according to tumor location and supraclavicular nodes should be included in regional nodes. Compared to the simplified N-category, the staging matrix of UICC system is somewhat complicated. The clinical stage and pathological stage of UICC system are not identical and difference exists also between squamous cell carcinoma (SCC) and adenocarcinoma. It has another system of pathological prognostic grouping. We can imagine several reasons for the difference occurred between the two systems. One is the difference of major pathology. Another reason is the difference of basic concept of cancer treatment. The relative "dependence" on radical surgery in Japan has required the detailed definition of each lymph node station and the evaluation of "efficacy index" of each station. The strict and detailed definition of lymph node stations has been regarded as an obstacle to those who are not familiar with it. Some simplification can be done but maintaining dynamic definition of regional lymph nodes linked to tumor location. If UICC system can accept this concept, I think the two systems can be unified to realize more practical and useful staging system as an international common language.