Increased resected lymph node stations improved survival of esophageal squamous cell carcinoma

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) and surgery have been recommended as the standard treatments for locally advanced esophageal squamous cell carcinoma (ESCC). In addition, nodal metastases decreased in frequency and changed in distribution after neoadjuvant therapy. This study aimed to examine the optimal strategy for lymph node dissection (LND) in patients with ESCC who underwent nCRT.

METHODS

The hazard ratios (HRs) for overall survival (OS) and disease-free survival (DFS) were calculated using the Cox proportional hazard model. To determine the minimal number of LNDs (n-LNS) or least station of LNDs (e-LNS), the Chow test was used.

RESULTS

In total, 333 patients were included. The estimated cut-off values for e-LNS and n-LNS were 9 and 15, respectively. A higher number of e-LNS was significantly associated with improved OS (HR: 0.90; 95% CI 0.84-0.97, P = 0.0075) and DFS (HR: 0.012; 95% CI: 0.84-0.98, P = 0.0074). The e-LNS was a significant prognostic factor in multivariate analyses. The local recurrence rate of 23.1% in high e-LNS is much lower than the results of low e-LNS (13.3%). Comparable morbidity was found in both the e-LNS and n-LND subgroups.

CONCLUSION

This cohort study revealed an association between the extent of LND and overall survival, suggesting the therapeutic value of extended lymphadenectomy during esophagectomy. Therefore, more lymph node stations being sampled leads to higher survival rates among patients who receive nCRT, and standard lymphadenectomy of at least 9 stations is strongly recommended.

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.

Abdominal lymph node metastasis in non-surgical esophageal squamous cell carcinoma: prognostic significance and a novel staging strategy

Purpose

This study aimed to evaluate the feasibility of a combination of abdominal lymph node (LN) metastasis and the number of LNs in esophageal squamous cell carcinoma (ESCC) patients to optimize its clinical nodal staging.

Methods

A retrospective study, including a total of 707 ESCC patients treated with definitive radiotherapy, was conducted at two participating institutes. Different combinations of LN variables, including abdominal LN metastasis (R1: no-abdominal LN metastasis; R2: abdominal LN metastasis), were further analyzed to propose a potential revised nodal (rN) staging.

Results

The multivariate analyses showed that the number of metastatic LN and abdominal LN metastasis were independent prognostic factors for the overall survival (OS). The results showed no significant differences in the OS between the N2 patients with abdominal LN metastasis and N3 patients. The OS of the stage III patients with abdominal LN metastasis was not significantly different from those with stage IVa. The N3R1 and N1-2R2 had similar hazard ratios (HRs). The N1R1 subset was defined as rN1, the N2R1 subset was defined as rN2, and the N3R1-2 and N1-2R2 subsets were defined as rN3. The HRs of OS of the rN2 and rN3 groups increased subsequently. The rN stage could identify the differences in the OS times of each subgroup based on the 8th AJCC cN staging or the 11th JES N staging.

Conclusions

The rN staging, including the number of metastatic LNs and abdominal LN metastasis, might serve as a potential prognostic predictor for non-surgical patients with ESCC.

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.

Pararespiratory and paradigestive lymph node metastases in esophageal squamous cell carcinoma: predicting survival and refining the N staging system

BACKGROUND

The site of lymph node metastasis (LNM) may affect the prognosis of patients with esophageal squamous cell carcinoma (ESCC). To investigate the prognoses of pararespiratory and paradigestive LNM and to propose a novel N (nN) staging system that integrates both the LNM site and count.

METHODS

This study was a multicenter, large-sample, retrospective cohort study that included ESCC patients with LNM between January 2014 and December 2019 from three Chinese institutes. Patients were set into training (two institutes) and external validation (one institute) cohorts. The primary outcomes were survival differences in LNM site and the development of novel nodal staging system. The overall survival (OS) of patients with pararespiratory LNM only (Group A), paradigestive LNM only (Group B), and both sites (Group C) was evaluated by Kaplan-Meier. Cox proportional hazards models were used to identify the independent prognostic factors. An nN staging system considering both the LNM site and count was developed and evaluated by the area under the receiver operating characteristic curve (AUC).

RESULTS

In total, 1313 patients were included and split into training (n = 1033) and external validation (n = 280) cohorts. There were 342 (26.0%), 568 (43.3%) and 403 (30.7%) patients in groups A, B and C, respectively. The OS of patients with pararespiratory and patients with paradigestive LNM presented significant differences in the training and validation cohorts (P < 0.050). In the training cohort, LNM site was an independent prognostic factor (hazard ratio: 1.58, 95% confidence intervals: 1.41-1.77, P < 0.001). The nN staging definition: nN1 (1-2 positive pararespiratory/paradigestive LNs), nN2 (3-6 pararespiratory LNs or 1 pararespiratory with 1paradigestive LN), nN3 (3-6 LNs with ≥ 1 paradigestive LN), nN4 (≥ 7 LNs). Subsets of patients with different nN stages showed significant differences in OS (P < 0.050). The prognostic model of the nN staging system presented higher performance in the training and validation cohorts at 3-year OS (AUC, 0.725 and 0.751, respectively) and 5-year OS (AUC, 0.740 and 0.793, respectively) than the current N staging systems.

CONCLUSIONS

Compared to pararespiratory LNM, the presence of paradigestive LNM is associated with worse OS. The nN staging system revealed superior prognostic ability than current N staging systems.

Clinical outcomes of salvage radiotherapy in patients with supraclavicular lymph node metastases after esophagectomy

Purpose

To evaluate the clinical outcomes of salvage radiotherapy in patients with supraclavicular lymph node (SCLN) metastases after esophagectomy.

Methods

After initial esophagectomy (R0 resection), clinical outcomes in patients with esophageal squamous cell carcinoma with SCLN metastases during follow-up were retrospectively analyzed.

Results

A total of 114 patients were split into two groups: the salvage radiotherapy (SR) (n=89) and the control (NSR) (without salvage radiotherapy, n=25). The overall survival rates of 1 year, 3 years and 5 years were 81.6%, 31.4% and 8.6%, accordingly. The 1-year and 3-year survival after SCLN metastases (SASM) rates were 40.2% and 14.5%, respectively; the median SASM time was 10 months. In the SR group, the SASM rates of 1-year and 3-year were 48.1% and 18.9%, compared to 12.0% and 0% in the NSR group (p<0.001). Patients in the SR group who received combined radiochemotherapy experienced 1-year and 3-year SASM rates of 62.6% and 33.4%, compared to 41.9% and 16.5% with single radiotherapy (p<0.001). The salvage radiation dose revealed that the 1-year and 3-year SASM rates turned out to be 56.5% and 23.4% in group of ≥60 Gy, and 29.2% and 7.5% in group of <60 Gy (p<0.001). According to multivariate analysis, combined visceral metastases (CVM), combined mediastinal failure (CMF), salvage radiotherapy, salvage radiation dose and salvage treatment method possibly were identified as important prognostic variables. After propensity score matching (PSM), the above results were similar to those before PSM, except for that only salvage radiotherapy is possibly independent prognostic variables for survival after SCLN metastases in multivariate analysis.

Conclusion

It is possible that salvage radiotherapy can increase the survival rate of patients who receive SCLN metastases following esophagectomy.

Thoracic para-aortic lymph node recurrence in patients with esophageal squamous cell carcinoma: A propensity score-matching analysis

BACKGROUND

Thoracic para-aortic lymph node (TPLN) recurrence in esophageal squamous cell carcinoma (ESCC) is rare and its impact on survival is unknown. We studied survival in patients with ESCC who developed TPLN recurrence.

AIM

To study the survival in patients with ESCC who developed TPLNs recurrence.

METHODS

Data were collected retrospectively for 219 patients who had undergone curative surgery for ESCC during January 2012 to November 2017 and who developed recurrences (36.29% of 604 patients who had undergone curative surgeries for ESCC). The patients were classified into positive (+) and negative (-) TPLN metastasis subgroups. We also investigated TPLN recurrence in 223 patients with ESCC following definitive chemoradiotherapy during 2012-2013. Following propensity score matching (PSM) and survival estimation, factors predictive of overall survival (OS) were explored using a Cox proportional hazards model.

RESULTS

Among the patients with confirmed recurrence, 18 were TPLN (+) and 13 developed synchronous distant metastases. Before PSM, TPLN (+) was associated with worse recurrence-free (P = 0.00049) and OS [vs TPLN (-); P = 0.0027], whereas only the intergroup difference in recurrence-free survival remained significant after PSM (P = 0.013). The Cox analysis yielded similar results. Among the patients who had received definitive chemoradiotherapy, 3 (1.35%) had preoperative TPLN enlargement and none had developed recurrences.

CONCLUSION

TPLN metastasis is rare but may be associated with poor survival.

Lymph node metastasis is not associated with survival in patients with clinical stage T4 esophageal squamous cell carcinoma undergoing definitive radiotherapy or chemoradiotherapy

Background

Clinical T4 stage (cT4) esophageal tumors are difficult to be surgically resected, and definitive radiotherapy (RT) or chemoradiotherapy (dCRT) remains the main treatment. The study aims to analyze the association between the status of lymph node (LN) metastasis and survival outcomes in the cT4 stage esophageal squamous cell carcinoma (ESCC) patients that underwent treatment with dCRT or RT.

Methods

This retrospective study analyzed the clinical data of 555 ESCC patients treated with dCRT or RT at the Shandong Cancer Hospital and the Liaocheng People’s Hospital from 2010 to 2017. Kaplan–Meier and Cox regression analyses was performed to determine the relationship between LN metastasis and survival outcomes of cT4 and non-cT4 ESCC patients. The chi-square test was used to evaluate the differences in the local and distal recurrence patterns in the ESCC patients belonging to various clinical T stages.

Results

The 3-year survival rates for patients with non-cT4 ESCC and cT4 ESCC were 47.9% and 30.8%, respectively. The overall survival (OS) and progression-free survival (PFS) rates were strongly associated with the status of LN metastasis in the entire cohort (all P &lt; 0.001) and the non-cT4 group (all P &lt; 0.001) but not in the cT4 group. The local recurrence rates were 60.7% for the cT4 ESCC patients and 45.1% for the non-cT4 ESCC patients (P &lt; 0.001). Multivariate analysis showed that clinical N stage (P = 0.002), LN size (P = 0.007), and abdominal LN involvement (P = 0.011) were independent predictors of favorable OS in the non-cT4 group. However, clinical N stage (P = 0.824), LN size (P = 0.383), and abdominal LN involvement (P = 0.337) did not show any significant correlation with OS in the cT4 ESCC patients.

Conclusions

Our data demonstrated that the status of LN metastasis did not correlate with OS in the cT4 ESCC patients that received dCRT or RT. Furthermore, the prevalence of local recurrence was higher in the cT4 ESCC patients.

miR-145-3p Hampers the Malignant Progression of Esophageal Carcinoma via CXCL5 Downregulation

Esophageal carcinoma (EC) is the most prevalent malignant tumor that occurs frequently worldwide. The early diagnostic biomarkers are crucial for EC treatment. miRNA can regulate EC progression, with diagnostic and prognostic value. Herein, differentially expressed miRNAs and mRNAs (DEmRNAs) in EC were predicted based on TCGA database. The target mRNAs of miRNA were predicted through databases, which were then intersected with DEmRNAs. Next, the correlation between miRNA and candidate mRNAs was analyzed. qRT-PCR was introduced to analyze expression of miR-145-3p and CXCL5 mRNA in EC cell lines, and western blot was performed to assess protein expression of CXCL5. Cell proliferation, migration, invasion, and apoptosis in EC were examined through CCK-8, wound healing, Transwell invasion, and flow cytometry assays. Moreover, targeting relationship between miR-145-3p and CXCL5 was verified through luciferase reporter gene analysis. The experimental results revealed a decreased miR-145-3p expression and an increased CXCL5 expression in EC. Enforced expression of miR-145-3p hindered proliferation, migration, invasion, and stimulated apoptosis of EC cells by repressing CXCL5. This study manifested that miR-145-3p may be a tumor suppressor in EC, and miR-145-3p/CXCL5 axis restrained the malignant progression of EC. These results supply an underlying target for prognosis and treatment of EC patients.

Should the Supraclavicular Lymph Nodes be Considered Regional Lymph Nodes in Cervical Esophageal Cancer?

BACKGROUND

The importance of supraclavicular lymph node (SCLN) metastases in esophageal cancer (EC) remains unknown. Few studies have reported on the prognostic impact of SCLN metastases on patients with cervical EC (CEC). This study aimed to investigate whether SCLNs should be considered regional lymph nodes and be dissected in patients with CEC.

METHODS

This retrospective study enrolled 835 consecutive patients who underwent radical esophagectomy. Of these patients, 67 underwent radical surgery for CEC. These 67 patients were divided into three groups based on the presence of lymph node metastases with or without metastatic SCLNs or the absence of lymph node metastases.

RESULTS

Of the 67 patients, 23 (34.3%) did not have metastatic lymph nodes (pN-negative group), 27 (40.3%) had metastatic lymph nodes except for metastatic SCLNs (pN-positive group without metastatic SCLN), and 17 (25.4%) had metastatic lymph nodes including metastatic SCLNs (pN-positive group with metastatic SCLNs). The 5-year overall survival rate was 58.4% for the pN-negative group, 46.2% for the pN-positive group without metastatic SCLNs, and 7.8% for the pN-positive group with metastatic SCLNs. The pN-positive group with metastatic SCLNs tended to show residual tumor cells and complications after surgery. The presence of metastatic SCLNs was a significantly poor prognostic factor (p = 0.004). The efficacy index was lowest for the lymph nodes in the supraclavicular region.

CONCLUSIONS

The prognosis of the CEC patients with metastatic SCLNs was dismal. Although the cervical esophagus is located adjacent to the SCLNs, the SCLNs may be considered extra-regional lymph nodes in patients with CEC.

The prognostic performance of the log odds of positive lymph nodes in patients with esophageal squamous cell carcinoma: A population study of the US SEER database and a Chinese single-institution cohort

Background

The purpose of this study was to assess the prognostic performance of the log odds of positive lymph nodes (LODDS) value compared with the pathological N stage and lymph node ratio (LNR) in patients with esophageal squamous cell carcinoma (ESCC).

Method

In total 1144 patients diagnosed with ESCC from the Surveillance, Epidemiology, and End Results (SEER) database and 930 patients from our validation cohort were eligible. Kaplan–Meier plotter and multivariate Cox proportional hazards models were conducted to investigate the prognostic value of the N stage, LNR stage, and LODDS stage. The homogeneity, discriminatory ability, and monotonicity of these variables were evaluated using the linear trend χ² test, likelihood ratio χ² test, Akaike information criterion (AIC), and consistency index (C‐index) to determine the potential superiorities.

Results

The prognostic LODDS cutoff values were determined to be −1.49 and −0.55 (p < 0.001). Univariate analyses showed significant association among the N, LNR, and LODDS stages and overall survival of the patients (all p < 0.001). Multivariate analyses confirmed that the LODDS stage remained an independent prognostic indicator in both the SEER database and our validation cohort. Subgroup analyses identified the ability of LODDS stage to distinguish heterogeneous patients within various groups in both independent databases. Furthermore, the model with the highest C‐index and smallest AIC value was the one incorporating the LODDS stage among the three investigated nodal classifications of both cohorts.

Conclusion

The novel LODDS stage demonstrated better prognostic performance than the traditional N or LNR stages in ESCC patients. It can serve as an auxiliary factor to improve prognostic performance and can be applied to evaluate the lymph node status to increase the precision of staging and evaluation of survival.

Clinical practice and outcome of radiotherapy for advanced esophageal squamous cell carcinoma between 2002 and 2018 in China: the multi-center 3JECROG Survey

PURPOSE

To determine the survival and prognostic factors of esophageal squamous cell carcinoma (ESCC) patients undergoing radical (chemo)radiotherapy in the era of three-dimensional conformal radiotherapy (3DCRT) and intensity modulated radiotherapy (IMRT) in China.

MATERIAL AND METHODS

The Jing-Jin-Ji Esophageal and Esophagogastric Cancer Radiotherapy Oncology Group (3JECROG) conducted the first nationwide survey of nine institutions. Detailed information was accumulated on 5185 patients with ESCC who received definitive 3DCRT/IMRT between 2002 and 2018. Relevant prognostic factors were evaluated to assess their influence on overall and progression-free survivals.

RESULTS

After a median follow-up time of 47.0 (0.9-157.4) months, the 1-year, 2-year, 3-year and 5-year overall survival rates of the whole group were 69.8%, 46.6%, 37.9% and 30.1%. The 1-year, 2-year, 3-year, and 5-year progression-free survival rates were 54.1%, 36.6%, 30.5% and 24.9%. Multivariate analysis demonstrated that sex, clinical stage, treatment modality and radiation dose were prognostic factors for OS. The survival of patients who received concurrent chemoradiotherapy (CCRT) was better than that of patients who received radiotherapy alone or sequential chemoradiotherapy. Patients receiving adjuvant chemotherapy after CCRT had a better OS than patients receiving CCRT alone. Patients receiving higher radiation dose had a better OS than those patients receiving low-dose radiotherapy.

CONCLUSIONS

The survival of ESCC patients undergoing radical (chemo)radiotherapy was relatively satisfactory in the era of 3DCRTand IMRT. As the largest-scale multicenter research on esophageal cancer radiotherapy conducted in China, this study establishes national benchmarks and helps to provide references for subsequent related researches.

Meta-analysis of prognostic factors of overall survival in patients undergoing oesophagectomy for oesophageal cancer

INTRODUCTION

Currently, the American Joint Commission on Cancer (AJCC) staging system is used for prognostication for oesophageal cancer. However, several prognostically important factors have been reported but not incorporated. This meta-analysis aimed to characterize the impact of preoperative, operative, and oncological factors on the prognosis of patients undergoing curative resection for oesophageal cancer.

METHODS

This systematic review was performed according to PRISMA guidelines and eligible studies were identified through a search of PubMed, Scopus, and Cochrane CENTRAL databases up to 31 December 2018. A meta-analysis was conducted with the use of random-effects modeling to determine pooled univariable hazard ratios (HRs). The study was prospectively registered with the PROSPERO database (Registration: CRD42018157966).

RESULTS

One-hundred and seventy-one articles including 73,629 patients were assessed quantitatively. Of the 122 factors associated with survival, 39 were significant on pooled analysis. Of these. the strongly associated prognostic factors were 'pathological' T stage (HR: 2.07, CI95%: 1.77-2.43, P < 0.001), 'pathological' N stage (HR: 2.24, CI95%: 1.95-2.59, P < 0.001), perineural invasion (HR: 1.54, CI95%: 1.36-1.74, P < 0.001), circumferential resection margin (HR: 2.17, CI95%: 1.82-2.59, P < 0.001), poor tumor grade (HR: 1.53, CI95%: 1.34-1.74, P < 0.001), and high neutrophil:lymphocyte ratio (HR: 1.47, CI95%: 1.30-1.66, P < 0.001).

CONCLUSION

Several tumor biological variables not included in the AJCC 8th edition classification can impact on overall survival. Incorporation and validation of these factors into prognostic models and next edition of the AJCC system will enable personalized approach to prognostication and treatment.

The Pattern of Residual Tumor After Neoadjuvant Chemotherapy for Locally Advanced Esophageal Cancer and Its Clinical Significance

OBJECTIVES

To investigate the residual pattern of esophageal cancer in the esophageal wall after neoadjuvant chemotherapy (NAC) and its clinical significance.

BACKGROUND

NAC is a standard treatment for locally advanced esophageal cancer; however, residual tumor patterns in resected specimens after NAC and their clinico-pathological characteristics remain unknown.

METHODS

One hundred twenty consecutive patients with cT3 or deeper esophageal cancer underwent curative esophagectomy after NAC and achieved grade 2 histological responses between 2000 and 2016. Hematoxylin-eosin staining of residual tumor sections revealed 4 remnant categories: Type 1: shallow, Type 2: central, Type 3: deep, and Type 4: diffuse. We examined associations between these Types and clinico-pathological factors, including prognosis.

RESULTS

Forty-five (38%) specimens had no residual tumor cells in the mucosal layer. The adventitia layer displayed the lowest residual tumor cell frequency (18%) among all layers. Types 1, 2, 3, and 4 residual tumor patterns were found in 49 (41%), 33 (28%), 9 (8%), and 29 (24%) patients, respectively. Type 4 showed the maximum standard uptake value after NAC; Types 3 and 4 had higher ratios of venous invasion than Type 1 or 2. Patients with Type 3 or 4 more frequently developed pleural dissemination or distant metastasis than patients with Type 1 or 2. Survival was similar among the 4 Types.

CONCLUSIONS

After NAC for locally advanced esophageal cancer, the shallow residual tumor pattern was most common, but approximately 40% of specimens showed no tumor cells in the mucosal layer. Deep and diffuse remnant patterns were associated with high risks of pleural dissemination and distant metastasis.

MiR-126 promotes esophageal squamous cell carcinoma via inhibition of apoptosis and autophagy

MiRNA-126 (miR-126) has been shown to be involved in various malignancies as well as other biological processes. However, currently, its role in esophageal squamous cell carcinoma (ESCC) is not well understood. The present study is focused on the mechanisms that underlie the effect of miR-126 on cell survival and death (apoptosis and autophagy) in ESCC cells. MiR-126 expression was found to be enhanced in ESCC cells and tissues. Downregulation of miR-126 suppressed cell survival, and TUNEL staining indicated that miR-126 inhibition promoted ESCC cell death. In addition, the production of LC3B and p62 proteins, two autophagy signals, was reduced following miR-126 inhibition. A dual luciferase reporter assay demonstrated that the STAT3 3’-UTR is a direct target of miR-126. Furthermore, STAT3 knock-down rescued the effects on autophagy and apoptosis caused by miR-126 inhibition in ESCC cells. The results of this study may provide some insight into the molecular and biological mechanisms underlying ESCC generation and contribute to the development of novel therapeutic approaches for ESCC.

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.

The impact of the nodal status on the overall survival of non-surgical patients with esophageal squamous cell carcinoma

BACKGROUND

The prognosis of N categories for patients with non-surgical esophageal carcinoma based on the number of metastatic lymph nodes is controversial. The present study analyzes prognostic implications of the number, extent, and size of metastatic lymph nodes for patients with esophageal squamous cell carcinoma (ESCC) treated with definitive (chemo-)radiotherapy to provide more information on treatment strategy.

METHODS

We reviewed 357 ESCC patients treated with definitive radiotherapy between January 2013 and March 2016 retrospectively. We assessed potential associations between the involved extent (N0, 1 region, 2 regions, and 3 regions), number (N0, 1-2, 3-6, and ≥ 7), and size (N0, ≤2 cm, and > 2 cm) of metastatic lymph nodes and overall survival. Multivariate analyses of the clinicopathological factors were performed using the Cox proportional hazard model.

RESULTS

5-year survival rates were 43.6% for patients in the N0 group and 29.3% in the N+ group (p = 0.001). Kaplan-Meier analyses for all cases revealed that there were significant differences in survival based on the extent (the OS rates at 3 years were 53.3% for patients in the N0 group, 45.7% in the 1 region-involved group, 28.0% in the 2 regions-involved group, and 13.3% in the 3 regions-involved group, P < 0.001), number (the OS rates at 3 years were 49.0% for patients in the 1-2 LNs group, 27.8% in the 3-6 LNs group, 0 in the ≥7LNs group, P < 0.001), and size (the OS rates at 3 years were 41.6% for patients in the LNs ≤2 cm group and 20.7% in the LNs > 2 cm group, P = 0.001) of metastatic LNs. One hundred seventy-two patients (48.2%) had experienced GTV failure, 157 (43.1%) had distant failure, 49 (13.7%) had out-of-GTV nodal failure, and 70 patients (19.6%) had no evidence of disease at the last follow-up. Nodal status correlated statistically with GTV failure. Patients with LN metastases in the abdominal region had worse survival rates than those with metastases in the other regions. The extent and number of metastatic LNs, T category, Primary tumor location, and chemotherapy were independent prognostic factors of OS in multivariate analyses.

CONCLUSIONS

For patients with ESCC who received definitive (chemo-)radiotherapy, the number, extent, and size of metastatic LNs were prognostic factors, particularly of the T2/3 disease. Patients with LN metastases in the abdominal region had worse survival.

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.

Aberrant promoter 2 methylation‑mediated downregulation of protein tyrosine phosphatase, non‑receptor type 6, is associated with progression of esophageal squamous cell carcinoma

The human protein tyrosine phosphatase, non‑receptor type 6 (PTPN6) gene is located on chromosome 12p13 and encodes an Mr 68,000 non‑receptor type protein‑tyrosine phosphatase. The PTPN6 gene has been considered as a candidate tumor suppressor in hematological and solid malignancies, and promoter methylation may be an epigenetic modification silencing its expression. However, the detailed role of PTPN6 and its promoter methylation status in the pathogenesis of esophageal squamous cell carcinoma (ESCC) has not been fully elucidated. The aim of the present study was to investigate PTPN6 expression in ESCC tissues and esophageal cancer cell lines, detect the effect of CpG hypermethylation on the activity of PTPN6, and additionally elucidate the role and prognostic significance of PTPN6 in ESCC tumorigenesis and progression. The expression of PTPN6 was identified to be significantly downregulated in esophageal cancer cell lines and ESCC tissues. Marked upregulation of PTPN6 was detected in 5‑aza‑2'‑deoxycytidine‑treated esophageal cancer cells, and frequent hypermethylation of the CpG sites within the P2 promoter (P2) was detected in ESCC tissues and esophageal cancer cell lines. The expression and methylation status of PTPN6 was associated with tumor node metastasis stage, pathological differentiation and lymph node metastasis in patients with ESCC. Aberrant hypermethylation of the P2 exhibited marked tumor specificity and was identified to be associated with the expression level of PTPN6. Downregulation and hypermethylation of PTPN6 were identified to be associated with poor ESCC patient survival. Furthermore, upregulation of PTPN6 inhibited the proliferation and invasion of esophageal cancer cells in vitro. The results of the present study suggest that PTPN6 may serve as a tumor suppressor in ESCC, and it may serve as a potential target for antitumor therapy.

Identifying the differentially expressed microRNAs in esophagus squamous cell carcinoma of Kazakh patients in Xinjiang

Despite improvements in diagnosis and treatment, the survival of patients with advanced stages of esophageal squamous cell carcinoma (ESCC) remains poor. Therefore, novel biomarkers that can assist with early detection of ESCC are required. In the present study, three paired ESCC and normal esophageal tissue samples from Xinjiang Kazakh patients were obtained and microRNA (miRNA) microarray analysis was used to detect the differentially-expressed miRNAs. The target genes of the identified miRNAs were predicted using miRWalk software. A total of 23 miRNAs were differently expressed in Kazakh patients with ESCC. Gene Ontology enrichment analysis demonstrated that the upregulated miRNAs were predominantly associated with the ‘vesicle’ and ‘membrane-bounded vesicle’ terms, while the downregulated miRNAs were primarily associated with the term ‘negative regulation of integrin-mediated signaling pathway’. The most highly enriched Kyoto Encyclopedia of Genes and Genomes pathway for the differentially-expressed miRNAs was ‘Endocrine and other factor-regulated calcium reabsorption’. Protein-protein interaction network analysis revealed that IQ motif containing GTPase activating protein 1, RAB11A, lysine acetyltransferase 2B, catenin α 1 and tight junction protein 2 were hub genes of the network. In conclusion, a number of differentially-expressed miRNAs were identified in ESCC tissues samples from Xinjiang Kazakh patients, which may improve the understanding of the processes of tumorigenesis and development.

Proposed revision of N categories to the 8th edition of the AJCC-TNM staging system for non-surgical esophageal squamous cell cancer

The 8th edition of the American Joint Committee on Cancer Tumor‐Node‐Metastasis (AJCC‐TNM) staging system for esophageal cancer (EC) retained the definition of N categories based on the number of metastatic lymph nodes (LN). However, it is difficult to accurately determine the number of metastatic LN without surgery. This study aimed to propose a revision to the N categories of the 8th edition AJCC‐TNM staging system that makes staging easier to perform and better represents the prognosis of non‐surgical esophageal squamous cell cancer (ESCC). We retrospectively reviewed the data of 336 patients with ESCC. The revised N categories were based on the anatomic regions of LN metastasis (cervix, thorax and abdomen). Survival was analyzed using the Kaplan‐Meier method and compared using the log‐rank test. Multivariate analyses were performed using the Cox proportional hazard model. Survival differences were adequately discriminated when the revised N categories were used. Subgroup analyses by T stage showed significant difference in overall survival between the revised N categories. Multivariate analyses demonstrated that T stage, revised N category, age, sex and treatment modality were independent risk factors, with the revised N category being the most significant variable. The revised N categories determined in this study can be used to fill gaps in the staging system for patients with non‐surgical ESCC, which can help clinicians to make better treatment decisions and more effectively predict patient prognoses. Future large‐scale studies are required to validate these results.

Supraclavicular and celiac metastases in squamous cell carcinoma of the middle thoracic esophagus

PURPOSE

Squamous cell carcinoma of the middle thoracic esophagus (SCC-ME) often metastasizes to the neck, mediastinum, and abdomen. This study aims to assess the prognostic impact of supraclavicular (SC) and celiac (CE) lymph node (LN) metastases in patients with SCC-ME.

METHODS

We examined 210 patients who underwent curative esophagectomy with three-field LN dissection for SCC-ME. The clinicopathological features and survival outcomes of patients with and without SC and/or CE metastases were compared to assess the prognostic significance of SC and/or CE metastases.

RESULTS

We observed metastases to SC and CE in 25 (11.9%) and 20 (9.5%) patients, respectively. Seven patients (3.3%) had both SC and CE metastases. Although the survival of patients with SC and/or CE metastases was worse compared with those without, that of patients with SC metastases but without CE metastases was comparable with that of patients with CE metastases but without SC metastases; the 5 year overall survival rates were 35.6% and 46.2%, respectively. However, survival of patients with both SC and CE metastases was the worst among all groups, and all patients with both SC and CE metastases experienced disease recurrence.

CONCLUSIONS

The prognosis of patients with both SC and CE metastases was extremely poor. In contrast, patients with metastasis to either one of these sites could be candidates for surgery as the main modality in a multidisciplinary strategy.

Overexpression of Peroxiredoxin 6 (PRDX6) Promotes the Aggressive Phenotypes of Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies. Peroxiredoxin 6 (PRDX6), a member of peroxidase superfamily, has a function of eliminating the reactive oxygen species (ROS), and participates in development of multiple diseases, including tumors. The purpose of this study was to investigate the expression of PRDX6 in normal and cancerous esophageal tissues and to characterize its role in ESCC progression. We found significantly higher expression of PRDX6 in ESCC tissues than in normal esophageal tissues or tumor-adjacent tissues and that the PRDX6 expression level was positively correlated with the proliferation-related markers. In ESCC cells, PRDX6 distribution was more pronounced in the nucleus region. PRDX6 overexpression by an adenovirus significantly promoted cell proliferation, migration and invasion in TE-1 and Eca-109 cells. Conversely, lentivirus-mediated knock-down of PRDX6 expression significantly reduced cell growth, colony formation and metastasis in ESCC cells. PRDX6 modulated the phosphorylation of Akt and Erk1/2, and the expression of MMP2. We also found that PRDX6 and Erk1/2 pathway were mutually regulated in ESCC cells. In addition, PRDX6 overexpression eliminated radiation-induced ROS and decreased consequent cell apoptosis, indicative of a role in radioresistance. Finally, the role of PRDX6 in promoting tumor growth was further confirmed in nude mice with ESCC xenografts. Taken together, we demonstrated that overexpression of PRDX6 promotes the progression of ESCC through Erk1/2, which provides a potential therapeutic target for human ESCC.

The clinical impact of supraclavicular lymph node metastasis in patients with locally advanced esophageal squamous cell carcinoma receiving curative concurrent chemoradiotherapy

Background

To evaluate the clinical significance of supraclavicular lymph node (SCLN) in patients with locally advanced esophageal squamous cell carcinoma (ESCC) receiving curative concurrent chemoradiotherapy (CCRT).

Materials and methods

We retrospectively analyzed all 369 locally advanced ESCC patients treated with CCRT between 2000 and 2015, including 70 patients with SCLN metastasis and 299 patients without SCLN metastasis.

Results

For these locally advanced ESCC patients treated with curative CCRT, N0-2 were significantly associated with superior progression-free survival (PFS) and overall survival (OS) in univariate and multivariable analyses. However, there were no significant differences in PFS and OS between the SCLN metastasis and non-SCLN metastasis groups; a subgroup analysis also revealed there was no significant differences in PFS and OS between patients with and without SCLN metastasis either in the N0-2 or in the N3 subgroup analysis.

Conclusions

Our study suggests that SCLN metastasis is not a prognostic factor in locally advanced ESCC patients receiving curative CCRT, and that SCLNs should be considered to be regional LNs and treated with curative intent.

Proposed modifications of supraclavicular lymph node metastasis in the esophageal squamous cell carcinoma staging system for improved survival stratification

The present study aims to investigate the clinical implication of supraclavicular lymph nodes (SCLNs) in thoracic esophageal squamous cell carcinoma (ESCC). A total of 1156 ESCC patients who underwent three-field lymphadenectomy with node metastasis were analyzed retrospectively. SCLNs were defined as regional nodes in the current system or as distant nodes in the modified system. Survival was analyzed using the Kaplan-Meier method, and values were compared using the log-rank test. Multivariate analysis was performed using the Cox proportional hazard model. The Akaike information criterion (AIC) and the concordance index (c-index) were applied to compare the two prognostic systems. Among 1156 patients, 183 (15.8%) patients were diagnosed with SCLN metastasis. Higher rate of SCLN metastasis was associated with upper tumor location, metastasis involving seven or more nodes, and positive recurrent laryngeal nerve node status. The current staging system was unable to stratify overall survival well in patients with N2, N3, and M1 status using a univariate analysis. In both the current staging system and the modified version, age, gender, pathological T status, and nodal status were independent prognostic factors in a multivariate analysis. The AIC value for the modified version was smaller than that for the current staging system; the c-index value for the modified version was larger than that for the current staging system. Based on the data from our single center, SCLNs should be reclassified as regional lymph nodes in thoracic ESCC for better stratification of overall survival.

Pattern of lymph node metastasis in thoracic esophageal squamous cell carcinoma with poor differentiation

The aim of the present study was to explore the pattern of lymph node metastasis (LNM) in poorly-differentiated esophageal squamous cell carcinoma (pdESCC) and the implication of postoperative irradiation. A total of 690 patients with pdESCC were retrospectively investigated. The rates of intro-thoracic and extra-thoracic LNM in pdESCC were investigated and compared to previous research on ESCC en bloc. The comparison of the rates between pdESCC and ESCC were performed using the Cochran-Mantel-Haenszel test. The clinicopathological factors associated with LNM in pdESCC were analyzed by Chi-squared tests, and Fisher's exact test was used to assess the rate difference of extra-thoracic LNM. Logistic-regression analysis was used to explore risk factors associated with lymph node (LN) station. Results demonstrated that the distribution pattern of LNM in pdESCC was significantly different compared with that of ESCC (P<0.05). Univariate and multivariate analysis indicated that risk factors associated with LNM were depth and length (P<0.001 and P<0.001) and multivariate analysis also indicated that the location of the tumor (P=0.042) was a risk factor associated with LNM in pdESCC. Metastasis in the abdominal cavity was significantly higher than in the neck in the middle and lower thoracic pdESCC (both P<0.01). LN station 102 and 7 for upper thoracic ESCC, 101 and 105 for middle thoracic ESCC, and 100 for lower thoracic ESCC were identified as high-risk stations for metastases in pdESCC compared to ESCC. Several parameters, including location and neck metastasis, were identified as risk factors of metastasis for the above sites, respectively. In conclusion, postoperative therapy should include more LN stations in pdESCC depending on risk factors of tumor metastasis individually.

A new classification of lymph node metastases according to the lymph node stations for predicting prognosis in surgical patients with esophageal squamous cell carcinoma

Lymph node metastasis (LNM) is one of the major prognostic factors for esophageal squamous cell carcinoma (ESCC). However there is no consensus regarding the prognostic significance of the location of LNM. Therefore, a novel classification was proposed to identify the lymph node (LN) stations which may be useful in predicting prognosis. A total of 260 ESCC patients were enrolled in this prospective study. The prognostic values of LNM in different lymph node (LN) stations were evaluated by random survival forests (RSF). Their prognostic significance was examined by Cox regression and receiver operating characteristic curve (ROC). The three most frequently involved LN stations were station 16 (24.49%), station 1 (22.22%) and station 2 (21.05%). Stations 1, 2, 8M, 8L and 16 were grouped as dominant LN stations (DLNS) which showed higher values in predicting overall survival (OS) and disease-free survival (DFS) than the remaining LN stations, which we define as non-dominant LN stations (N-DLNS). LNM features of DLNS (number of positive LN stations, number of positive LNs and LN ratio), but not those from N-DLNS, served as independent prognostic factors (P<0.05) whenever used alone or when combined with factors from N-DLNS. Furthermore, the area under ROC indicated that DLNS is a more accurate prediction than N-DLNS (P<0.05). This study demonstrated the value of LNM in DLNS in predicting prognosis in surgical ESCC patients, which outperformed those from N-DLNS. Therefore, the method of dominant and non-dominant classification may serve as an additional parameter to improve individualized therapeutic strategies.

Elevated Nectin-2 expression is involved in esophageal squamous cell carcinoma by promoting cell migration and invasion

Nectin-2 is overexpressed in cancer cells and is associated with poor prognosis in patients with various types of cancers. However, its involvement in esophageal squamous cell carcinoma (ESCC) remains unknown. The present study aimed to investigate the expression pattern of Nectin-2, its clinical significance and its roles in the malignant phenotypes of ESCC. Expression levels of Nectin-2 mRNA and protein were respectively detected by reverse transcription-quantitative polymerase chain reaction, western blotting and immunohistochemistry, based on 106 newly diagnosed ESCC patients. The associations between Nectin-2 expression and clinicopathological characteristics of ESCC patients were statistically analyzed. The effects of Nectin-2 in migration and invasion were then determined by wound healing and Transwell assays performed using ESCC cell lines (ECA109 and KYSE510) transfected with small interfering (si) RNA against Nectin-2. It was found that Nectin-2 expression was significantly elevated at the mRNA and protein levels in ESCC tissues, compared with the normal esophageal mucosa (P<0.001). Nectin-2-positive immunoreactivity was mainly localized in the cytoplasm of cancer cells in ESCC tissues. In addition, the expression levels of Nectin-2 protein in ESCC tissues with advanced tumor stage (P=0.006) and poor differentiation (P=0.02) were increased compared with patients with early tumor stage and well to moderate differentiation. Additionally, knockdown of Nectin-2 in the 2 ESCC cell lines could effectively suppress the cell migration and invasion abilities (P<0.05). In conclusion, these findings revealed that Nectin-2 is generally overexpressed in ESCC and associated with aggressive cancer progression. The present data also indicated that the silencing of Nectin-2 with siRNA in ESCC cells may inhibit cell malignant biological properties, indicating its potential as a potential marker or a therapeutic target for ESCC.

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.

Strategies of nodal staging of the TNM system for esophageal cancer

The 8^th edition of UICC/AJCC TNM staging for esophageal cancer will start in use since 2018. The nodal staging in this version of TNM system remains unchanged from the 7^th edition that based on the number of lymph nodes (LN) involved, except the limited revision of the regional LN map. In this review, N staging revision was evaluated from its initially simple definition of negative (N0) and positive (N1) LN(s) to the current positive node number based proposal. Meanwhile the disadvantages of current N staging were discussed. The refined nodal staging system in view of the number of metastatic node stations was introduced; as well as the extent and station of metastatic node could better reflect the disease progression and prognosis. The controversy on N staging of esophagogastric junction cancer was also discussed. Other reported N staging associated elements including LN ratio and lymphatic vessel invasion were reviewed and evaluated.

Clinical outcomes and benefits for staging of surgical lymph node mapping after esophagectomy

Dissection of lymph nodes (LN) immediately after esophagectomy is utilized by some surgeons to aid determination of LN stations involved in esophageal cancer. Some suggest that this increases LN yield and gives information regarding the pattern of lymphatic spread, others feel that this may compromise a circumferential resection margin (CRM) assessment. The aim of this study is to evaluate the effect of ex vivo dissection on the assessment of the CRM and the pattern of lymph node dissemination in patients with adenocarcinoma of the esophagus and gastroesophageal junction (GEJ) undergoing radical surgery after neoadjuvant chemotherapy and their prognostic impact. Data from consecutive patients with potentially curable adenocarcinoma of the distal esophagus and GEJ who received neoadjuvant treatment followed by surgery were analyzed. Clinical and pathological findings were reviewed and LN burden and location correlated with clinical outcome. Pathology specimens were dissected into individual LN groups 'ex-vivo' by the surgeon. A total of 301 patients were included: 295 had a radical proximal and distal resection margin however in 62(20.6%) CRM could not be assessed. A median of 33(10-77) nodes were recovered. A 117(38.9%) patients were ypN0 while 184(61.1%) were LN positive (ypN1-N3). LN stations close to the tumor were most frequently involved. Twenty-seven (14.7%) patients had only thoracic stations involved, 48(26.1%) only abdominal stations and 109 (59.2%) had both. Median survival for yN0 patients was 171 months compared to 24 months for those LN positive (P< 0.001). Multivariate analyses identified ypT-category, ypN-category, male gender, and nonradical resection (proximal or distal) margin as significant prognostic factors. Surgical dissection of nodes after esophagectomy enables accurate LN assessment, but may compromise CRM assessment in up to 20% of cases. It also provides valuable information regarding the pattern of nodal spread.

New classification for the thoracic paraaortic lymph nodes of patients with esophageal squamous cell carcinoma

PURPOSE

To create a new classification for the thoracic paraaortic lymph nodes (No. 112ao) of patients with esophageal squamous cell carcinoma (ESCC). Classification of these nodes in ESCC patients has been the focus of very few reports.

METHODS

The subjects of this study were 27 patients with positive No. 112ao nodes on computed tomography (CT) images before treatment. We divided the No. 112ao nodes into No. 112aoA, located on the esophageal side as anterior No. 112ao nodes, and No. 112aoP, located on the opposite side of the esophagus as posterior No. 112ao nodes. We examined the association between No. 112aoA and No. 112aoP and clinicopathological factors. Recurrence-free survival (RFS) was compared between the No. 112aoA- and No. 112aoP-positive groups.

RESULTS

There were 12 patients in the No. 112aoA-positive group and 15 patients in the No. 112aoP-positive group. The No. 112aoP-positive group had significantly worse RFS than the No. 112aoA-positive group (p = 0.004). Cox multivariate analysis of RFS revealed that No. 112aoP positivity was an independent prognostic factor (p = 0.043).

CONCLUSIONS

Our new classification of No. 112ao nodes into No. 112aoA and No. 112aoP is useful clinically. No. 112aoP could correspond to the clinical N4 category of patients with ESCC.

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.

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.

Investigation of operative outcomes of thoracoscopic esophagectomy after triplet chemotherapy with docetaxel, cisplatin, and 5-fluorouracil for advanced esophageal squamous cell carcinoma

BACKGROUND

Preoperative chemotherapy with cisplatin and 5-fluorouracil (CF) has become the standard treatment for resectable stage II/III thoracic esophageal carcinoma in Japan. Recently, preoperative triplet chemotherapy with docetaxel, cisplatin, and 5-fluorouracil (DCF) has been reported to be effective for locally advanced esophageal cancer. Thoracoscopic esophagectomy (TE) has been increasingly accepted worldwide for the treatment of esophageal cancer. We conducted a retrospective study to evaluate the safety and outcomes of TE after DCF therapy for patients with advanced esophageal cancer.

METHODS

The medical records of 63 consecutive patients with esophageal squamous cell carcinoma who underwent thoracoscopic surgery after chemotherapy were reviewed. Thirty-four patients received neoadjuvant chemotherapy with CF, and 29 received DCF as first-line chemotherapy.

RESULTS

The clinical T stage was significantly higher in the DCF group than in the CF group (p < 0.0001), including 17 patients with T4. Lymph node metastasis was more frequent in the DCF group (p = 0.0005), and the clinical stage of the tumor was significantly higher in the DCF group than in the CF group (p = 0.0001). No significant difference existed between the two groups in operation time for the thoracic procedure (DCF 277.2 min vs. CF 302 min). Blood loss during the thoracic procedure was less in the DCF group than in the CF group (DCF 46.9 mL vs. CF 88.8 mL; p = 0.0056). No significant differences existed between the two groups in postoperative morbidity (DCF 34.5% vs. CF 47%) or mortality (DCF 0% vs. CF 2.9%) rates.

CONCLUSIONS

Our study suggests that TE after DCF therapy for advanced esophageal cancer is as safe as TE after CF therapy.

Clinical significance of ZNF750 gene expression, a novel tumor suppressor gene, in esophageal squamous cell carcinoma

The present authors previously identified a novel candidate tumor suppressor gene, zinc finger protein 750 (ZNF750), in esophageal squamous cell carcinoma (ESCC) (1). The present study aimed to clarify the clinical significance of ZNF750 expression in ESCC. The association between ZNF750 DNA mutation status and the mRNA expression was examined by whole exome sequence analysis and quantitative reverse transcription polymerase chain reaction (RT-qPCR). The expression of ZNF750 in 76 patients with ESCC (Kyushu University Beppu Hospital) was measured using immunohistochemistry and RT-qPCR. Using this dataset, the association between ZNF750 mRNA expression and clinicopathological factors was examined. Additionally, survival analysis was performed using datasets from the Kyushu University Beppu Hospital and The Cancer Genome Atlas (TCGA). The biological effects of ZNF750 expression were explored using gene set enrichment analysis (GSEA) and were validated using datasets from the Cancer Cell Line Encyclopedia (CCLE) and the Kyushu University Beppu Hospital. ZNF750 expression analyses demonstrated that ZNF750 mRNA expression was lower in patients with the DNA mutations compared with those without the mutations (P<0.05), and ZNF750 expression was downregulated in tumor tissues compared with normal tissues (P<0.00005). In the clinicopathological analysis, the low ZNF750 expression group exhibited a higher incidence of undifferentiated histology (P<0.05) compared with the high expression group. The low ZNF750 expression group exhibited a poorer prognosis in the Kyushu and TCGA datasets (P<0.0005 and P<0.05, respectively). GSEA indicated that ZNF750 expression was significantly correlated with epithelial differentiation in ESCC. This was confirmed using the datasets from CCLE and the Kyushu University Beppu Hospital by analyzing the levels of small proline rich protein 1A mRNA, an epithelial differentiation-associated gene. In conclusion, the results of the present study suggested that ZNF750 serves a role as a tumor suppressor; potentially via regulating epithelial differentiation and that it may be a promising biomarker of poor outcomes in ESCC.

Prognostic value of supraclavicular nodes and upper abdominal nodes metastasis after definitive chemoradiotherapy for patients with thoracic esophageal squamous cell carcinoma

The purpose of this study is to assess the prognostic value of supraclavicular nodes, left gastric nodes, celiac nodes and common hepatic nodes metastasis in esophageal squamous cell carcinoma (ESCC) treated with definitive radiotherapy. A total of 293 ESCC patients treated with radiotherapy or chemoradiotherapy entered the study. The results showed that the presence of supraclavicular nodes (χ² = 0.075, P = 0.785) and left gastric nodes (χ² = 3.603, P = 0.058) metastasis had no significant influence on survival, while celiac nodes (χ² = 33.775, P < 0.001) and common hepatic nodes (χ² = 42.350, P < 0.001) metastasis were associated with significantly shorter survival, regardless of the sites of primary tumor. Multivariate analysis showed that celiac nodes (HR: 0.457, 95% CI: 0.256-0.816; P = 0.008) and common hepatic nodes (HR: 0.241, 95% CI: 0.092-0.630; P = 0.004) metastasis were independently adverse indicator of survival in upper ESCC. While in the middle and lower ESCC, only the common hepatic nodes (middle ESCC: HR: 0.345, 95% CI: 0.161-0.738, P = 0.006; lower ESCC: HR: 0.377, 95% CI: 0.160-0.890, P = 0.026) metastasis was an independently adverse indicator of survival. In conclusion, our study demonstrated that in ESCC treated with definitive radiotherapy, both of celiac nodes and common hepatic nodes metastasis were adverse indicator of survival in upper ESCC, and common hepatic nodes metastasis were adverse indicator of survival in middle and lower ESCC. Supraclavicular nodes an left gastric nodes metastasis is not associated with patients survival in ESCC.

Decreased expression of CD63 tetraspanin protein predicts elevated malignant potential in human esophageal cancer

The tetraspanin CD63 has been described to have critical roles in multiple biological processes, including tumorigenesis and metastasis in several types of cancer. However, its role in esophageal carcinoma (EC) has not been reported. In the current study, immunohistochemistry was used to investigate CD63 expression in 106 esophageal cancer samples, 49 adjacent esophagus tissues and 17 normal esophagus mucosa tissues. The results revealed that the overexpression of CD63 was observed in esophageal cancer samples and negatively correlated with tumor stage and lymph node metastasis. To further evaluate the role of CD63 in esophageal carcinoma, the invasiveness of EC cells was analyzed using matrigel invasion assays and wound healing assays in vitro. Furthermore, it was found that CD63 knockdown increased the invasiveness of TE-1 cells through the upregulation of matrix metalloproteinase (MMP) expression via promoting epithelial-mesenchymal transition. The current data therefore suggested that low levels of CD63 expression may be involved in the tumor progression of esophageal carcinoma.

Distribution patterns of metastases in recurrent laryngeal nerve lymph nodes in patients with squamous cell esophageal cancer

Esophageal cancers frequently metastasize to recurrent laryngeal nerve lymph nodes (RLNNs). Knowledge of anatomic metastatic RLNN (mRLNN) distributions is needed for lymph node dissection during esophageal cancer surgery. Among 189 patients with esophageal cancer who underwent esophagectomy between 2008 and 2010, 51 (27.0%) had mRLNN. Sixty-four mRLNNs (right, 31; left, 33) were identified via preoperative computed tomography (CT); more than 2 unilateral metastases and/or nodes with unclear boundaries were excluded. Anatomical characteristics, including vertical distance from the sternal notch level, circumferential angle to the mid-sagittal tracheal plane, and short and long axes, were measured via CT. Respective mean right and left vertical distances from the sternal notch were +2.0 ± 13.1 mm and -14.5 ± 23.8 mm (p = 0.0006). Left mRLNNs existed in vertically wider and inferior areas along recurrent laryngeal nerve, compared to right mRLNNs. The respective mean right and left circumferential angles around the trachea (from the anterior mid-sagittal plane) were 137.2 ± 11.2° and 94.3 ± 31.6° (p < 0.0001). Left mRLNNs were distributed more widely around the trachea, especially anteriorly. The short axes were larger for right mRLNNs than for left mRLNNs (8.6 mm vs. 6.8 mm, p = 0.026). Compared with the right side, left mRLNNs were smaller and had a vertically longer and circumferentially wider distribution. Careful attention should be given to the left side during curative RLNN dissection.

Supraclavicular node disease is not an independent prognostic factor for survival of esophageal cancer patients treated with definitive chemoradiation

BACKGROUND

The prognostic value of supraclavicular lymph node (SCN) metastases in esophageal cancer is not well established. We analyzed the prognostic value of SCN disease in patients after definitive chemoradiation (dCRT) for esophageal cancer.

METHODS

We retrospectively analyzed 207 patients treated between 2003 and 2013 to identify the prognostic value of metastasis in the SCN on treatment failure and survival. All patients were treated with external beam radiotherapy (50.4 Gy in 28 fractions) combined with weekly concurrent paclitaxel 50 mg/m² and carboplatin AUC2.

RESULTS

Median follow-up for patients alive was 43.3 months. The median overall survival (OS) for all patients was 17.5 months. OS at one, three and five years was 67%, 36% and 21%, respectively. For patients with metastasis in a SCN, OS was 23.6 months compared to 17.1 months for patients without metastasis in the SCN (p = .51). In multivariate analyses, higher cT status, cN status and adenocarcinoma were found to be prognostically unfavorable, but a positive SCN was not (p = .67). Median OS and median disease-free survival for tumors with SCN involvement and N0/1 disease was 49.0 months and 51.6 months, respectively, compared to 14.2 months and 8.2 months, respectively, in patients with N2/3 disease.

CONCLUSION

In esophageal cancer treated with dCRT, the number of affected lymph nodes is an important independent prognostic factor, whereas involvement of a SCN is not. Supraclavicular lymph nodes should be considered as regional lymph nodes and treated with curative intent if the total number of involved lymph nodes is limited.

Recommendations for pathologic staging (pTNM) of cancer of the esophagus and esophagogastric junction for the 8th edition AJCC/UICC staging manuals

We report analytic and consensus processes that produced recommendations for pathologic stage groups (pTNM) of esophageal and esophagogastric junction cancer for the AJCC/UICC cancer staging manuals, 8th edition. The Worldwide Esophageal Cancer Collaboration provided data for 22,654 patients with epithelial esophageal cancers; 13,300 without preoperative therapy had pathologic assessment after esophagectomy or endoscopic treatment. Risk-adjusted survival for each patient was developed using random survival forest analysis to identify data-driven pathologic stage groups wherein survival decreased monotonically with increasing group, was distinctive between groups, and homogeneous within groups. The AJCC Upper GI Task Force, by smoothing, simplifying, expanding, and assessing clinical applicability, produced consensus pathologic stage groups. For pT1-3N0M0 squamous cell carcinoma (SCC) and pT1-2N0M0 adenocarcinoma, pT was inadequate for grouping; subcategorizing pT1 and adding histologic grade enhanced staging; cancer location improved SCC staging. Consensus eliminated location for pT2N0M0 and pT3N0M0G1 SCC groups, and despite similar survival, restricted stage 0 to pTis, excluding pT1aN0M0G1. Metastases markedly reduced survival; pT, pN, and pM sufficiently grouped advanced cancers. Stage IIA and IIB had different compositions for SCC and adenocarcinoma, but similar survival. Consensus stage IV subgrouping acknowledged pT4N+ and pN3 cancers had poor survival, similar to pM1. Anatomic pathologic stage grouping, based on pTNM only, produced identical consensus stage groups for SCC and adenocarcinoma at the cost of homogeneity in early groups. Pathologic staging can neither direct pre-treatment decisions nor aid in prognostication for treatment other than esophagectomy or endoscopic therapy. However, it provides a clean, single therapy reference point for esophageal cancer.

Survival outcomes of 220 consecutive patients with three-staged thoracoscopic esophagectomy

Patients with thoracic esophageal cancer are often treated by minimally invasive esophagectomy. However, the long-term survival benefits of minimally invasive esophagectomy remain unclear. Two approaches are available for thoracoscopic surgery: one with the patient in the left lateral decubitus position (LLDP), and the other with the patient in the prone position (PP). We investigated the survival benefit of thoracoscopic esophagectomy according to the tumor stage and patient position during the thoracoscopic procedure. We reviewed the records of 220 consecutive patients with esophageal cancer treated from 1998 to 2012. In total, 146 and 74 patients were treated with thoracoscopic esophagectomy in the LLDP and PP, respectively. No patients were initially proposed to be candidates for esophagectomy by thoracotomy during the study period. Data collection was performed with a focus on survival and recurrent disease. Among all the 220 patients, the overall 5-year survival rates were 83.7%, 74.1%, 45.5%, 78.6%, 44.2%, 29.4% and 24.3% in the patients with pStage IA, IB, IIA, IIB, IIIA, IIIB and IIIC disease, respectively. Despite the greater number of dissected mediastinal lymph nodes in the PP procedure, there were no significant differences in the survival curves between the LLDP and PP procedures. The long-term results of thoracoscopic esophagectomy are comparable and acceptable. The PP procedure was not confirmed to offer a superior survival benefit to the LLDP procedure in this retrospective study.

A new method (the "Pincers maneuver") for lymphadenectomy along the right recurrent laryngeal nerve during thoracoscopic esophagectomy in the prone position for esophageal cancer

BACKGROUND

In esophageal squamous cell carcinoma, the number of dissected lymph nodes (LNs), including those along the recurrent laryngeal nerves (RLNs), influences prognosis and nodal staging accuracy. However, dissection of LNs along the RLN increases the risk of complications, especially RLN palsy. Therefore, complete dissection of these LNs with prevention of RLN palsy is recommended. We present herein a new method for lymphadenectomy along the right RLN, named the Pincers maneuver, during thoracoscopic esophagectomy in the prone position (TEP).

METHODS

The fundamental concept in this new method is to first exfoliate the two-dimensional membrane (lateral pedicle), which includes the right RLN, LNs along the right RLN, and the primary esophageal artery, from the right side of the trachea toward the neck. Using a Pincers strategy, closing in from the inner and outer sides of the two-dimensional membrane (lateral pedicle), lymphadenectomy along the right RLN toward the right inferior thyroid artery should be easy. This technique was evaluated in 30 consecutive cases of TEP for squamous cell cancer.

RESULTS

There were 15 patients who underwent the new method (Pincers maneuver; Pm) and 15 patients who underwent the conventional method (Cm). There were no significant differences between the two groups in the duration of the thoracic procedure and dissection along the right RLN. No intraoperative and postoperative morbidity related to the right RLN was observed in either group. The Pm group had a higher number of dissected LNs along the right RLN than the Cm group (6.3 vs 3.1, p = 0.044).

CONCLUSIONS

The Pincers maneuver for lymphadenectomy along the right RLN during TEP is technically safe and feasible. It increases the number of dissected LNs along the right RLN.

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.

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.

MicroRNA-202 inhibits tumor progression by targeting LAMA1 in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive malignancies in the gastrointestinal tract. Emerging studies have indicated that microRNAs (miRNAs) are strongly implicated in the development and progression of ESCC. Here, we focused on the function and the underlying molecular mechanism of miR-202 in ESCC. The results showed that miR-202 was significantly down-regulated in ESCC tissues and cell lines. Overexpression of miR-202 in ECa-109 and KYSE-510 cells markedly suppressed cell proliferation and cell migration, and induced cell apoptosis. Furthermore, laminin α1 (LAMA1) expression was frequently positive in ESCC tissues and inversely correlated with miR-202 expression. Then we demonstrated that miR-202 targeted 3'-untranslated region (UTR) of LAMA1 and inhibited its protein expression. Additionally, LAMA1 overexpression rescued the proliferation inhibition and cell apoptosis elevation induced by miR-202. MiR-202 also inhibited the protein expression of p-FAK and p-Akt, which were all reversed by LAMA1 overexpression. Taken together, these findings suggest that miR-202 may function as a novel tumor suppressor in ESCC by repressing cell proliferation and migration, and its biological effects may attribute the inhibition of LAMA1-mediated FAK-PI3K-Akt signaling.

Prognostic nomogram for previously untreated patients with esophageal squamous cell carcinoma after esophagectomy followed by adjuvant chemotherapy

OBJECTIVE

The aim of the study was to establish an effective prognostic nomogram for esophageal squamous cell carcinoma after radical esophagectomy followed by adjuvant chemotherapy in those previously untreated patients.

METHODS

The clinicopathological data from 328 patients who underwent radical esophagectomy followed by adjuvant chemotherapy or not at the Tianjin Medical University Cancer Institute and Hospital between 2006 and 2010 were retrospectively studied. Nomograms which predicted survival of esophageal squamous cell carcinoma were established based on the Cox proportional hazards regression model. To determine its predictive accuracy and discriminatory capacity, the concordance index and calibration curve were calculated after bootstrapping in the internal validation. An external validation of 76 patients in 2011 was prospectively studied at the same institution. To verify the performance of the nomogram, the comparison between the nomogram and Tumor-Node-Metastasis staging system was conducted.

RESULTS

The 5-year overall survival was 43.1% in the primary cohort. Based on multivariate analyses, five independent prognostic variables including gender, tumor length, T stage, N stage and chemotherapy cycles were selected to build the nomograms to predict disease-free survival and overall survival. The concordance index of the nomogram to predict overall survival was 0.71 (95% confidence interval, 0.63-0.79), which was superior to the predictive power of Tumor-Node-Metastasis staging system (0.64) in the primary cohort. Meanwhile, the calibration curve showed good accuracy between predictive and actual overall survival. In the validation cohort, the concordance index (0.77) and calibration plot displayed favorable performances. The other nomogram to predict disease-free survival also performed well.

CONCLUSIONS

The prognostic nomogram provided individualized risk estimate of survival in patients after esophagectomy followed by adjuvant chemotherapy.

MiR-328 suppresses the survival of esophageal cancer cells by targeting PLCE1

Esophageal cancer (EC) is the sixth leading cause of death worldwide. Recent studies have highlighted the vital role of microRNAs (miRNAs) in EC development and diagnosis. In our study, qPCR analysis showed that miRNA-328 was expressed at significantly low levels in EC109 and EC9706 cells. The results also showed that overexpression of miR-328 by lentivirus-mediated gene transfer markedly inhibited cell proliferation and invasion, and enhanced apoptosis; whereas, inhibition of miR-328 significantly promoted cell proliferation and invasion, and suppressed apoptosis in EC109 and EC9706 cells. Dual-luciferase reporter assay confirmed that miR-328 directly targeted phospholipase C epsilon 1 (PLCE1) by binding to target sequences in the 3'-UTR. qPCR and Western blot analysis showed that the PLCE1 was overexpressed in EC109 and EC9706 cells. Additionally, we found that miR-328 overexpression decreased PLCE1 mRNA and protein levels, while miR-328 inhibition enhanced the PLCE1 expression. Further analysis showed that PLCE1 overexpression rescued the inhibitory effect of miR-328 on cell proliferation and invasion, and repressed the promotive effect of miR-328 on cell apoptosis. In conclusion, our results suggest that miR-328 suppresses the survival of EC cells by regulating PLCE1 expression, which might be a potential therapeutic method for EC.