Detection of circulating oesophageal squamous cancer cells in peripheral blood and its impact on prognosis

Prognostic Value of Combination of Lymphocyte-to-Monocyte-Ratio and CYFRA 21-1 in Esophageal Squamous Cell Carcinoma

BACKGROUND

This study aimed to investigate the potential of a combined score based on CYFRA 21-1 level and LMR as a prognostic predictor for patients with ESCC.

METHODS

A total of 460 patients who underwent esophagectomy were analyzed, and three groups were established based on the CA-LMR score. OS and RFS were evaluated using the Kaplan-Meier analysis, and associated factors were analyzed by univariate and multivariate Cox analysis. A mpStage system was also established based on the CA-LMR score.

RESULTS

The allocation of CA-LMR score of 0, 1, and 2 was 107 (23.3%), 280 (60.9%), and 73 (15.9%). There was a significant association between CA-LMR and male gender (P = 0.001), lower BMI (P = 0.035), longer tumor lesions (P = 0.002), and high pT, pN, pStage (P < 0.001, P = 0.011, P = 0.001). The 5-year OS rates for CA-LMR scores of 0, 1, and 2 were 75.4%, 60.2%, and 32.8%, respectively (P < 0.001). Multivariate analysis showed that CA-LMR score (P = 0.011) was an independent prognostic factor for OS. The proposed mpStage system, based on CA-LMR score, demonstrated superior discriminatory ability, monotonicity, homogeneity, and prognosis prediction ability over AJCC 8th pStage system.

CONCLUSIONS

The CA-LMR score, combined with tumor marker and inflammatory index, could use as a potential prognostic indicator; moreover, our modified pStage system exhibited superior stratification and prognostic accuracy for patients with ESCC.

Circulating tumor cells detected in follow-up predict survival outcomes in tri-modality management of advanced non-metastatic esophageal cancer: a secondary analysis of the QUINTETT randomized trial

Background

Our aim was to establish if presence of circulating tumor cells (CTCs) predicted worse outcome in patients with non-metastatic esophageal cancer undergoing tri-modality therapy.

Methods

We prospectively collected CTC data from patients with operable non-metastatic esophageal cancer from April 2009 to November 2016 enrolled in our QUINTETT esophageal cancer randomized trial (NCT00907543). Patients were randomized to receive either neoadjuvant cisplatin and 5-fluorouracil (5-FU) plus radiotherapy followed by surgical resection (Neoadjuvant) or adjuvant cisplatin, 5-FU, and epirubicin chemotherapy with concurrent extended volume radiotherapy following surgical resection (Adjuvant). CTCs were identified with the CellSearch® system before the initiation of any treatment (surgery or chemoradiotherapy) as well as at 6-, 12-, and 24-months post-treatment. The threshold for CTC positivity was one and the findings were correlated with patient prognosis.

Results

CTC data were available for 74 of 96 patients and identified in 27 patients (36.5%) at a median follow-up of 13.1months (interquartile range:6.8-24.1 months). Detection of CTCs at any follow-up visit was significantly predictive of worse disease-free survival (DFS;hazard ratio [HR]: 2.44; 95% confidence interval [CI]: 1.41-4.24; p=0.002), regional control (HR: 6.18; 95% CI: 1.18-32.35; p=0.031), distant control (HR: 2.93; 95% CI: 1.52-5.65;p=0.001) and overall survival (OS;HR: 2.02; 95% CI: 1.16-3.51; p=0.013). After adjusting for receiving neoadjuvant vs. adjuvant chemoradiotherapy, the presence of CTCs at any follow-up visit remained significantly predictive of worse OS ([HR]:2.02;95% [Cl]:1.16-3.51; p=0.013) and DFS (HR: 2.49;95% Cl: 1.43-4.33; p=0.001). Similarly, any observed increase in CTCs was significantly predictive of worse OS (HR: 3.14; 95% CI: 1.56-6.34; p=0.001) and DFS (HR: 3.34; 95% CI: 1.67-6.69; p<0.001).

Conclusion

The presence of CTCs in patients during follow-up after tri-modality therapy was associated with significantly poorer DFS and OS regardless of timing of chemoradiotherapy.

Detection of Circulating and Disseminated Tumor Cells and Their Prognostic Value under the Influence of Neoadjuvant Therapy in Esophageal Cancer Patients

Simple Summary

Esophageal cancer (EC) has a poor prognosis and a high mortality rate. This study investigated the expression of CK20 and DEFA5, markers being associated with circulating (CTC) and disseminated tumor cells (DTC), in blood and bone marrow (BM) of EC patients, and correlated positivity rates with clinical data to assess the prognostic impact. Both markers were detected in blood and BM of EC patients and the control cohort so that a cut-off value was determined to define marker positivity for correlation with clinical parameters. CK20 and DEFA5 positivity in liquid biopsies of EC patients did not correlate with overall survival (OS). However, CK20 positivity in BM and DEFA5 negativity in blood were associated with reduced OS in patients without neoadjuvant therapy. In patients with neoadjuvant therapy, DEFA5 positivity in BM was associated with improved OS, pointing to the potential of DEFA5 as a prognostic biomarker in liquid biopsies of EC patients.

Abstract

Detection of circulating (CTC) or disseminated tumor cells (DTC) are correlated with negative prognosis in esophageal cancer (EC) patients. In this study, DTC- and CTC-associated markers CK20 and DEFA5 were determined by RT-PCR in EC patients and correlated with clinical parameters to determine their prognostic impact. The blood and bone marrow (BM) of 216 EC patients after tumor resection with or without neoadjuvant therapy and as control blood samples from 38 healthy donors and BM from 24 patients with non-malignant diseases were analyzed. Both markers were detected in blood and BM of EC patients and the control cohort. A cut-off value was determined to define marker positivity for correlation with clinical data. CK20 expression was detected in 47/206 blood samples and in 49/147 BM samples of EC patients. DEFA5 positivity was determined in 96/206 blood samples and 98/147 BM samples, not correlating with overall survival (OS). However, CK20 positivity in BM and DEFA5 negativity in blood were associated with reduced OS in EC patients without neoadjuvant therapy, while in patients with neoadjuvant therapy DEFA5 positivity in BM was associated with improved OS. Overall, our study suggests DEFA5 as a prognostic biomarker in liquid biopsies of EC patients which requires further validation.

Prognostic impact of circulating tumor cells detected with the microfluidic "Universal CTC-chip" for primary lung cancer

Detecting rare circulating tumor cells (CTCs) in the bloodstream is extremely challenging. We had previously developed a novel polymeric microfluidic device, "CTC-chip," for capturing CTCs and have shown high capture efficiency in lung cancer cell lines by conjugating antibodies against epithelial cell adhesion molecules (EpCAM). This study aimed to optimize the EpCAM-chip and clarify the prognostic impact of CTCs in lung cancer patients. Of the 123 patients with pathologically proven lung cancer, both progression-free survival (p = 0.037) and cancer-specific survival (p = 0.0041) were predominantly poor when CTCs were detected before treatment. After classification into surgical and chemotherapy groups, progression-free survival was worse in CTC-positive patients in both groups (surgery, p = 0.115; chemotherapy, p = 0.012), indicating that the detection of baseline CTCs is a risk factor for recurrence and progression. Furthermore, we demonstrated that captured CTCs can be recovered using micromanipulators and performed mutation analysis using PCR. Thus, the EpCAM-chip is a highly sensitive system for detecting CTCs that contributes to the prediction of recurrence and progression and enables genetic analysis of captured CTCs, which may open new diagnostic, therapeutic, and prognostic options for lung cancer patients.

Circulating Tumor Cells in Esophageal Squamous Cell Carcinoma - Mini Review

Esophageal cancer has high incidence and mortality rates and a low five-year survival rate of <15% owing to its strong capabilities of invasion, relapse and metastasis. The classic view holds that metastasis and diffusion is an advanced event during cancer progression, but recent studies show that distant diffusion of primary cancer cells may actually be an early event. Detection of circulating tumor cells (CTCs) in the circulation may indicate tumor spread, so CTCs are considered to be the key factor of metastatic cascade. In recent years, despite research progress on CTCs, there is a lack of systematic and important evidence to confirm the diagnostic, monitoring and prognostic values of CTCs in esophageal squamous cell carcinoma (ESCC). In this review, we clarify the relationship between CTC values and ESCC and provide more reliable evidence to improve the management and treatment of ESCC.

Clinical Significance of TWIST-Positive Circulating Tumor Cells in Patients with Esophageal Squamous Cell Carcinoma

Background/Aims

Unlike other gastrointestinal tract cancers, there are relatively few reports on the clinical significance of circulating tumor cells (CTCs) and TWIST, a marker of epithelial-mesenchymal transition, in patients with esophageal squamous cell carcinoma (ESCC). This study aimed to evaluate the clinical significance of TWIST expression in CTCs in patients with ESCC.

Methods

Peripheral blood samples for CTC analyses were prospectively obtained from 52 patients with ESCC prior to treatment between September 2017 and September 2019. CTCs were detected using a centrifugal microfluidic system based on a fluid-assisted separation technique, and CTCs positive for TWIST on immunostaining were defined as TWIST (+) CTCs.

Results

Of the 52 patients with ESCC, CTCs and TWIST (+) CTCs were detected in 44 patients (84.6%) and 39 patients (75.0%), respectively. The CTC and TWIST (+) CTC counts were significantly higher in patients aged >65 years and those who had a large tumor (>3 cm) than in those aged ≤65 years and those who had a small tumor (≤3 cm), respectively. There were no differences in CTC and TWIST (+) CTC counts according to tumor location, histologic grade, or TNM stage. TWIST (+) CTCs were significantly associated with histologic grade; a proportion of TWIST (+) CTCs ≥0.5 was significantly associated with advanced histologic grade. Other clinicopathologic characteristics such as sex, age, tumor location, tumor size, and TNM stages were not significantly associated with TWIST (+) CTCs.

Conclusions

Our study showed that TWIST (+) CTCs were frequently detected in patients with ESCC, and a high proportion of TWIST (+) CTCs was associated with poor differentiation.

The Diagnostic and Prognostic Value of a Liquid Biopsy for Esophageal Cancer: A Systematic Review and Meta-Analysis

Simple Summary

The “liquid biopsy” is a novel concept for detecting circulating biomarkers in the peripheral blood of patients with various cancers, including esophageal cancer. There are two main methods to identify circulating cancer related biomarkers such as morphological techniques or molecular biological techniques. There are some differences in the sensitivity and specificity for detecting circulating tumor cells (CTCs) or circulating markers between each method. Although it is still challenging to determine strong candidates for early diagnosis and predicting prognosis in patients with esophageal cancer, our meta-analysis might be a milestone for the future development of liquid biopsies in use with esophageal cancer.

Abstract

Esophageal cancer is among the most aggressive diseases, and circulating tumor cells (CTCs) have been recognized as novel biomarkers for various cancers over the past two decades, including esophageal cancer. CTCs might provide crucial clinical information for predicting cancer prognosis, monitoring therapeutic responses or recurrences, or elucidating the mechanism of metastasis. The isolation of CTCs is among the applications of a “liquid biopsy”. There are various technologies for liquid biopsies, and they are classified into two main methods: cytometric or non-cytometric techniques. Here, we review a total of 57 eligible articles to summarize various technologies for the use of a liquid biopsy in esophageal cancer and perform a meta-analysis to assess the clinical utility of liquid biopsies as a prognostic and diagnostic biomarker technique. For prognostic evaluation, the pooled hazard ratio in the cytometric assay is relatively higher than that of the non-cytometric assay. On the other hand, a combination of multiple molecules, using a non-cytometric assay, might be a favorable biomarker technique for the early diagnosis of esophageal cancer. Although determining strong evidence for a biomarker by using a liquid biopsy is still challenging, our meta-analysis might be a milestone for the future development of liquid biopsies in use with esophageal cancer.

Comparative Analysis of Blood and Bone Marrow for the Detection of Circulating and Disseminated Tumor Cells and Their Prognostic and Predictive Value in Esophageal Cancer Patients

Hematogenic tumor cell spread is a key event in metastasis. However, the clinical significance of circulating tumor cells (CTC) in the blood and disseminated tumor cells (DTC) in bone marrow is still not fully understood. Here, the presence of DTC and CTC in esophageal cancer (EC) patients and its correlation with clinical parameters was investigated to evaluate the CTC/DTC prognostic value in EC. This study included 77 EC patients with complete surgical tumor resection. CTC and DTC were analyzed in blood and bone marrow using nested CK20 reverse transcription-nested polymerase chain reaction (RT-PCR) and findings were correlated with clinical data. Twenty-seven of 76 patients (36.5%) showed CK20 positivity in the blood, 19 of 61 patients (31.1%) in bone marrow, and 40 (51.9%) of 77 patients were positive in either blood or bone marrow or both. In multivariate analyses, only the DTC status emerged as independent predictor of overall and tumor specific survival. Our study revealed that, while the presence of CTC in blood is not associated with a worse prognosis, DTC detection in the bone marrow is a highly specific and independent prognostic marker in EC patients. Larger cohort studies could unravel how this finding can be translated into improved therapy management in EC.

Preoperative chemotherapy compared with postoperative adjuvant chemotherapy for squamous cell carcinoma of the thoracic oesophagus with the detection of circulating tumour cells randomized controlled trial

BACKGROUND

The role of preoperative chemotherapy in the treatment of patients with oesophageal squamous cell carcinoma (ESCC) remains controversial. Chemotherapy followed by surgery was compared with surgery ± chemotherapy, and the detection of circulating tumour cells (CTCs) was performed on all enrolled patients.

METHODS

We randomly assigned patients with resectable tumours to the preoperative chemotherapy group (Pre group) or surgery group (patients who were either given or not given adjuvant chemotherapy according to their postoperative lymph node status, Post group). Blood samples were collected 1-3 days before treatment (including preoperative chemotherapy and surgery) and 7 days after surgery for CTC detection.

RESULTS

From July 2016 to October 2018, 115 patients were enrolled in the study, of whom 57 were assigned to the Pre group and 58 to the Post group. The proportion of patients with stage III ESCC was 63.16% in the Pre group and 48.28% in the Post group. No patients died during chemotherapy. One patient exhibited a complete response to preoperative chemotherapy, and 13 patients exhibited partial responses. The 2-year progression-free survival (PFS) and overall survival (OS) rates were not significantly different between the Pre and Post groups. In the subgroup analysis, patients with CTC (+) prior to treatments receiving preoperative chemotherapy had a better 2-year PFS (71.90% vs. 38.73%, P = 0.0379). In the Cox proportional hazards regression analysis, platelet count was proven to correlate significantly with disease progression (P = 0.016), and no factors were proven to correlate significantly with mortality after the factors were balanced in the present analysis.

CONCLUSIONS

Preoperative chemotherapy improved the short-term PFS when CTC detection was positive prior to any treatment for patients with stage II or III ESCC. CTC detection may be used as an index to guide individualized strategic decisions regarding preoperative chemotherapy, but more evidence is needed.

A Model Shows Utility in Predicting Postoperative Recurrence and Distant Metastasis in Curatively Resected Esophageal Squamous Cell Cancer

After curative treatment of esophageal squamous cell cancer (ESCC), patients are at high risk for recurrence. The objective of this study was to develop an index with a high sensitivity and specificity to predict ESCC patients’ recurrence and prognosis. A retrospective analysis was conducted on consecutive patients with EC who underwent esophagectomy. In total, 1417 patients were included in the current investigation. In total, 770 patients were included in the current study’s exploratory group. Alcohol consumption, TNM classification, number of lymph node station metastases, and number of lymph node metastases were significantly correlated with recurrence. Multivariate logistical regression analysis resulted in the development of an equation for predicting recurrence and prognosis (REEC). When using the REEC value to predict recurrence, the cutoff value was 1.095, the area under the curve (AUC) values of the REEC were 0.68 (p < 0.001) in the Exploratory Group and 0.65 (p < 0.001) in the Validation Group, and the sensitivity and specificity were 76.68% and 51.18%, respectively. When using the REEC value to predict prognosis, the cutoff value was 1.215, the AUC values of the REEC were 0.65 (p < 0.001) in the Exploratory Group and 0.64 (p < 0.001) in the Validation Group, and the sensitivity and specificity were 73.12% and 50.67%, respectively. In the Exploratory Group, when the REEC value was >1.095, patients had a longer median overall survival (OS) and median disease-free survival (DFS) than those whose REEC value was < 1.095 (70.01±2.01 months versus 50.92±2.85 months and 75.66±1.35 months versus 53.68±2.81 months, respectively, p < 0.001). The differences were confirmed to still exist in the Validation Group (48.12±1.47 vs 32.68±2.53 months and 55.61±1.32 vs 35.68±2.73 months respectively, p < 0.001).This study reported an index that can predict esophageal cancer recurrence and prognosis, and its use can benefit patients.

Isolation of circulating tumor cells in patients undergoing surgery for esophageal cancer and a specific confirmation method

The clinical significance of circulating tumor cells (CTCs) in patients with esophageal squamous cell carcinoma (ESCC) who have undergone radical surgery was investigated. A novel confirmation method for identifying CTCs or circulating tumor microemboli (CTM) in ESCC was also investigated. Blood samples from 55 patients with ESCC were collected 1–3 days prior to surgery and 7 days post-surgery. All patients underwent curative thoracic esophagectomy and lymphadenectomy. Blood samples from 20 healthy volunteers were obtained as controls. Isolation by size of epithelial tumor cells (ISET) was performed also. The overall CTC detection rate was 52.7% preoperatively and 49.1% postoperatively. The presence of CTCs correlated with the Tumor-Node-Metastasis stage and the Log odds of positive lymph nodes. No significant difference in perioperative CTC transformation was discovered between the thoracoscopic and laparoscopic approach, and the open approach. The P40⁺/cluster of differentiation (CD)45⁻ phenotype was confirmed in the CTCs and CTM. ISET appeared to have high sensitivity for detecting CTCs within ESCC patients. Immunofluorescence staining for CD45 and P40 was a specific, accurate and convenient method for confirming the presence of CTCs or CTM in patients with ESCC, and is strongly recommended as a supplement to morphological analysis.

Hybrid microfluidic sorting of rare cells based on high throughput inertial focusing and high accuracy acoustic manipulation

The ability to isolate rare circulating tumor cells (CTCs) from blood samples is essential to perform liquid biopsy as a routine diagnostic and prognostic test. Both label-free and surface biomarker-based cell sorting technologies have been developed to address the demand in high-integrity isolation of rare CTCs for cancer research. Label-free cell sorting mainly relies on the size difference between CTCs and blood cells; thus, it lacks sufficient sorting specificity. Surface biomarker-based cell sorting is highly specific; however, it requires expensive, labor-intensive, and time-consuming labeling due to the use of multiple sets of surface biomarkers. Because of the complex nature and high heterogeneity of tumorigenesis, it is difficult to rely on a single sorting process for high-integrity rare cell isolation. In this study, for the first time, we present a hybrid microfluidic cell sorting method combining high throughput size-dependent inertial focusing for size-based pre-enrichment and high accuracy fluorescence activated acoustic sorting for single cell isolation. After one single hybrid sorting process, we have demonstrated at least 2500-fold purity enrichment of MCF-7 breast cancer cells spiked in diluted whole blood samples with cell viability maintained at 91 ± 1% (viability before sorting was 94 ± 2%). This developed hybrid microfluidic cell sorting technique provides a promising solution for rare cell isolation needed in a variety of biological research and clinical applications.

The first example of integration of sized-based inertial sorting and surface biomarker-based acoustic sorting to achieve >2500-fold enrichment of rare cell populations.

Clinicopathological and prognostic significance of circulating tumor cells in patients with esophageal cancer: a meta-analysis

Background

The aim of this meta-analysis was to assess the clinicopathological and prognostic significance of circulating tumor cells (CTCs) in patients with esophageal cancer (EC).

Methods

We searched PubMed, EMBASE, Science Citation Index Expanded, Cochrane library (from inception to July 2018) with the keywords “esophageal cancer”, “circulating tumor cells”, “prognosis”, and “peripheral blood”. HR, risk ratio (RR), OR, and their 95% CIs were set as effect measures. All analyses were performed by STATA 12.0.

Results

Eighteen studies were retrieved; CTC-positive patients were significantly associated with poor progression-free survival (PFS) (HR=2.61; 95% CI=2.08–3.28) and overall survival (OS) (HR=2.50; 95% CI=2.12–2.94). CTC-positive patients were also associated with high recurrence (OR=2.84; 95% CI=1.81–4.44) and poor response of chemoradiotherapy (RR=0.64; 95% CI=0.43–0.96). For clinicopathological characteristics, CTC-positive patients were significantly associated with TNM staging, depth of infiltration, regional lymph nodes metastasis, distant metastasis, lymphatic invasion, and venous invasion.

Conclusion

The meta-analysis has confirmed the significant clinicopathological and prognostic value of CTC-positive patients for both PFS and OS in patients with EC.

Significant prognostic value of circulating tumor cells in esophageal cancer patients: A meta-analysis

Esophageal cancer is the sixth leading cause of cancer death worldwide. Detection of circulating tumor cells (CTCs) is emerging as a novel strategy for predicting cancer patient prognosis. Here we performed a comprehensive literature search to identify relevant articles in EMbase, PubMed, EBSCO, OVID, Cochrane Database, CNKI, WanFangdata and VIPdata. Meta-analysis was conducted using Stata12.0 software, according to the inclusion and exclusion criteria, extracted data and assessment methodology. Thirteen eligible literature studies were included with a total of 979 esophageal squamous cell carcinoma patients, including 424 CTC-positive and 684 CTC-negative cases. Meta-analysis showed that the presence of CTCs was associated with both worse progression-free/disease-free survival [hazard ration (HR) = 2.32, 95% confidence interval (CI) = 1.57 - 3.43, p < 0.001] and poorer overall survival [HR = 2.64, 95% CI = 1.69 - 4.14, p < 0.001]. Further subgroup analyses demonstrated that CTC-positive patients also showed worse progression-free/disease-free survival and poorer overall survival in different subsets. In summary, our meta-analysis provides strong evidence that detection of CTCs in the peripheral blood is an independent prognostic indicator of poor outcome for esophageal squamous cell carcinoma patients.

A rapid and quantitative method to detect human circulating tumor cells in a preclinical animal model

Background

As cancer metastasis is the deadliest aspect of cancer, causing 90% of human deaths, evaluating the molecular mechanisms underlying this process is the major interest to those in the drug development field. Both therapeutic target identification and proof-of-concept experimentation in anti-cancer drug development require appropriate animal models, such as xenograft tumor transplantation in transgenic and knockout mice. In the progression of cancer metastasis, circulating tumor cells (CTCs) are the most critical factor in determining the prognosis of cancer patients. Several studies have demonstrated that measuring CTC-specific markers in a clinical setting (e.g., flow cytometry) can provide a current status of cancer development in patients. However, this useful technique has rarely been applied in the real-time monitoring of CTCs in preclinical animal models.

Methods

In this study, we designed a rapid and reliable detection method by combining a bioluminescent in vivo imaging system (IVIS) and quantitative polymerase chain reaction (QPCR)-based analysis to measure CTCs in animal blood. Using the IVIS Spectrum CT System with 3D–imaging on orthotropic-developed breast-tumor-bearing mice.

Results

In this manuscript, we established a quick and reliable method for measuring CTCs in a preclinical animal mode. The key to this technique is the use of specific human and mouse GUS primers on DNA/RNA of mouse peripheral blood under an absolute qPCR system. First, the high sensitivity of cancer cell detection on IVIS was presented by measuring the luciferase carried MDA-MB-231 cells from 5 to 5x10¹¹ cell numbers with great correlation (R² = 0.999). Next, the MDA-MB-231 cell numbers injected by tail vein and their IVIS radiance signals were strongly corrected with qPCR-calculated copy numbers (R² > 0.99). Furthermore, by applying an orthotropic implantation animal model, we successfully distinguished xenograft tumor-bearing mice and control mice with a significant difference (p < 0.001), whereas IVIS Spectrum-CT 3D–visualization showed that blood of mice with lung metastasis contained more than twice the CTC numbers than ordinary tumor-bearing mice. We demonstrated a positive correlation between lung metastasis status and CTC numbers in peripheral mouse blood.

Conclusion

Collectively, the techniques developed for this study resulted in the integration of CTC assessments into preclinical models both in vivo and ex vivo, which will facilitate translational targeted therapy in clinical practice.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3419-x) contains supplementary material, which is available to authorized users.

Prognostic value of circulating tumor cells in esophageal cancer

AIM

To perform a meta-analysis of the related studies to assess whether circulating tumor cells (CTCs) can be used as a prognostic marker of esophageal cancer.

METHODS

PubMed, Embase, Cochrane Library and references in relevant studies were searched to assess the prognostic relevance of CTCs in patients with esophageal cancer. The primary outcome assessed was overall survival (OS). The meta-analysis was performed using the random effects model, with hazard ratio (HR), risk ratio (RR) and 95% confidence intervals (95%CIs) as effect measures.

RESULTS

Nine eligible studies were included involving a total of 911 esophageal cancer patients. Overall analyses revealed that CTCs-positivity predicted disease progression (HR = 2.77, 95%CI: 1.75-4.40, P < 0.0001) and reduced OS (HR = 2.67, 95%CI: 1.99-3.58, P < 0.00001). Further subgroup analyses demonstrated that CTCs-positive patients also had poor OS in different subsets. Moreover, CTCs-positivity was also significantly associated with TNM stage (RR = 1.48, 95%CI: 1.07-2.06, P = 0.02) and T stage (RR = 1.44, 95%CI: 1.13-1.84, P = 0.003) in esophageal cancer.

CONCLUSION

Detection of CTCs at baseline indicates poor prognosis in patients with esophageal cancer. However, this finding relies on data from observational studies and is potentially subject to selection bias. Prospective trials are warranted.

Circulating Tumor Cells in the Adenocarcinoma of the Esophagus

Circulating tumor cells (CTCs) are elements of indisputable significance as they seem to be responsible for the onset of metastasis. Despite this, research into CTCs and their clinical application have been hindered by their rarity and heterogeneity at the molecular and cellular level, and also by a lack of technical standardization. Esophageal adenocarcinoma (EAC) is a highly aggressive cancer that is often diagnosed at an advanced stage. Its incidence has increased so much in recent years that new diagnostic, prognostic and predictive biomarkers are urgently needed. Preliminary findings suggest that CTCs could represent an effective, non-invasive, real-time assessable biomarker in all stages of EAC. This review provides an overview of EAC and CTC characteristics and reports the main research results obtained on CTCs in this setting. The need to carry out further basic and translational research in this area to confirm the clinical usefulness of CTCs and to provide oncologists with a tool to improve therapeutic strategies for EAC patients was herein highlighted.

Circulating Tumor Cells as a Biomarker for Preoperative Prognostic Staging in Patients With Esophageal Cancer. Ann Surg. 2015;261:1124-1130. [PMID: 25607767 DOI: 10.1097/sla.0000000000001130]

OBJECTIVE

We evaluated the prognostic significance of circulating tumor cells (CTCs) in patients with esophageal cancer (EC).

BACKGROUND

Despite the availability of several preoperative diagnostic techniques, accurate pretreatment staging of EC remains challenging.

METHODS

In this single-center, prospective study, peripheral blood samples for CTC analyses were obtained preoperatively from 100 patients who were judged to have resectable EC. CTC detection was performed using the CellSearch System. Data were correlated with clinicopathological parameters and patient outcomes.

RESULTS

CTCs were detected in 18% (18/100) of all eligible patients. Patients with CTCs showed significantly shorter relapse-free (P < 0.001) and overall survival (P < 0.001) than CTC-negative patients. Even in patients with lymph node invasion and without distant metastases (pN+, M0, N = 45), CTC detection indicated significantly worse relapse-free (P < 0.001) and overall survival (P = 0.007). Multivariate analyses of eligible patients identified CTCs as a strong, independent, prognostic indicator of tumor recurrence (hazard ratio, 5.063; 95% confidence interval, 2.233-11.480; P < 0.001) and overall survival (hazard ratio, 3.128; 95% confidence interval, 1.492-6.559; P = 0.003).

CONCLUSIONS

This is the first study to report that CTCs detected by an automated immunomagnetic detection system are independent, prognostic indicators of patients' outcome in EC. Thus, implementation of CTCs may improve accuracy of preoperative staging in EC.

Prognostic significance of circulating tumor cells in esophageal carcinoma: a meta-analysis

PURPOSE

The prognostic significance of circulating tumor cells (CTCs) in esophageal carcinoma (EC) is controversial. We aim to assess its association with clinicopathological and prognostic relevance in EC by using a meta-analysis.

METHODS

We searched PubMed, Cochrane Database, Embase databases, and the references in relevant studies that assessed the clinicopathological or prognostic relevance of CTCs in peripheral blood of patients with EC. Statistical analyses were conducted by using Stata software to calculate the pooled odds ratio (OR), hazard ratio (HR), and 95% confidence intervals (CIs) using fixed or random-effects models according to the heterogeneity of included studies. The subgroup analyses were performed according to ethnicity, histological type, and detection method.

RESULTS

Sixteen trials containing 1,260 patients were included for analysis. Pooled results showed that presence of CTCs was significantly associated with poor overall survival (HR =1.71, 95% CI [1.30, 2.12], P<0.001) and progression-free survival (HR =1.67, 95% CI [1.19, 2.15], P<0.001) in EC patients. Subgroup analysis indicated that presence of CTCs was closely associated with worse overall survival (Asian: HR =1.66, 95% CI [1.24, 2.08], P<0.001; squamous cell carcinoma [SCC]: HR =1.66, 95% CI [1.24, 2.08], P<0.001; no polymerase chain reaction [PCR]: HR =2.08, 95% CI [1.40, 2.76], P<0.001) and progression-free survival (Asian: HR =1.63, 95% CI [1.15, 2.12], P<0.001; SCC: HR =1.63, 95% CI [1.15, 2.12], P<0.001; PCR: HR =1.63, 95% CI [1.15, 2.12], P<0.001). Additionally, ORs showed that presence of CTCs was significantly correlated with tumor node metastasis (TNM) staging (overall: OR = 1.96, 95% CI [1.34, 2.87], P=0.001; Asian: OR =2.09, 95% CI [1.37, 3.19], P=0.001; SCC: OR =1.97, 95% CI [1.21, 3.07], P=0.003; PCR: OR =2.23, 95% CI [1.43, 3.47], P<0.001), venous invasion (overall: OR =2.23, 95% CI [1.46, 3.40], P<0.001; Asian: OR =2.23, 95% CI [1.46, 3.40], P<0.001; SCC: OR =2.23, 95% CI [1.46, 3.40], P<0.001; PCR: OR =2.23, 95% CI [1.46, 3.40], P<0.001), lymph node metastasis (overall: OR =2.41, 95% CI [1.50, 3.86], P<0.001; Asian: OR =2.89, 95% CI [1.80, 4.65], P<0.001; SCC: OR =2.44, 95% CI [1.47, 4.07], P=0.001; PCR: OR =2.89, 95% CI [1.80, 4.65], P<0.001) and distant metastasis (Asian: OR =2.68, 95% CI [1.01, 7.08], P=0.047) in patients with EC.

CONCLUSION

The presence of CTCs indicates a poor prognosis in EC patients, especially in Asian and SCC patients. Further well-designed prospective studies are recommended to explore the clinical applications of CTCs in patients with EC.

Circulating Tumor Cell Analyses in Patients With Esophageal Squamous Cell Carcinoma Using Epithelial Marker-Dependent and -Independent Approaches

In several epithelial malignancies, detection of circulating tumor cells (CTCs) in the peripheral blood has diagnostic, prognostic, and therapeutic implications. However, the clinical relevance of CTCs in esophageal squamous cell carcinoma (ESCC) has not yet been ascertained. The study was conducted with the aim of determining the clinical significance of CTCs in patients with ESCC by using 2 CTC detection systems, one epithelial marker-dependent and the other epithelial marker-independent. Paired peripheral blood samples were prospectively obtained from 61 ESCC patients before treatment and were analyzed for CTCs isolated by the CellSearch system (CS) and the method of isolation by size of epithelial tumor (ISET). Blood samples from 22 healthy volunteers were used as controls. Out of 61 study subjects, CTCs were detected in 20 patients (32.8%) by the ISET method and in only 1 patient (1.6%) by the CS method. Circulating tumor microemboli (CTM) were observed in 3 of 61 (4.9%) patients using ISET, but were undetectable in any of the patient by CS method. No CTCs/CTM were detected by either method in control groups. By ISET method, the presence of CTCs appeared to correlate with the stage of ESCC and with the baseline median platelet levels. No correlation with any other relevant clinicopathological variables was observed. Our results clearly indicate the ability of both CS and ISET methods to detect CTCs in peripheral blood samples from ESCC patients. However, the CellSearch system appears to have a poorer sensitivity as compared with the ISET method. Further studies are essential for assessing the role of such technologies in ESCC.

Polymeric microfluidic devices exhibiting sufficient capture of cancer cell line for isolation of circulating tumor cells

Here, we developed polymeric microfluidic devices for the isolation of circulating tumor cells. The devices, with more than 30,000 microposts in the channel, were produced successfully by a UV light-curing process lasting 3 min. The device surface was coated with anti-epithelial cell adhesion molecule antibody by just contacting the antibody solution, and a flow system including the device was established to send a cell suspension through it. We carried out flow tests for evaluation of the device's ability to capture tumor cells using an esophageal cancer cell line, KYSE220, dispersed in phosphate-buffered saline or mononuclear cell separation from whole blood. After the suspension flowed through the chip, many cells were seen to be captured on the microposts coated with the antibody, whereas there were few cells in the device without the antibody. Owing to the transparency of the device, we could observe the intact and the stained cells captured on the microposts by transmitted light microscopy and phase contrast microscopy, in addition to fluorescent microscopy, which required fluorescence labeling. Cell capture efficiencies (i.e., recovery rates of the flowing cancer cells by capture with the microfluidic device) were measured. The resulting values were 0.88 and 0.95 for cell suspension in phosphate-buffered saline, and 0.85 for the suspension in the mononuclear cell separation, suggesting the sufficiency of this device for the isolation of circulating tumor cells. Therefore, our device may be useful for research and treatments that rely on investigation of circulating tumor cells in the blood of cancer patients.

Disseminated and circulating tumor cells in gastrointestinal oncology

Circulating (CTCs) and disseminated tumor cells (DTCs) are two different steps in the metastatic process. Several recent techniques have allowed detection of these cells in patients, and have generated many results using different isolation techniques in small cohorts. Herein, we review the detection results and their clinical consequence in esophageal, gastric, pancreatic, colorectal, and liver carcinomas, and discuss their possible applications as new biomarkers.

CEA-antigen and SCC-antigen mRNA expression in peripheral blood predict hematogenous recurrence after resection in patients with esophageal cancer

BACKGROUND

Although several studies have suggested an association between circulating tumor cells (CTC) and prognosis after esophageal cancer surgery, large-scale studies are lacking. The aim of this study was to prospectively examine the correlation between CTC and outcome in a large number of patients who underwent esophagectomy.

MATERIALS AND METHODS

A cohort of 244 patients with squamous cell carcinoma of the esophagus who underwent curative surgery between 2002 and 2007 were prospectively analyzed for CTC before surgery and after the thoracic procedure. Reverse transcription-polymerase chain reaction for CEA and SCC antigen mRNA was used to detect cancer cells in the peripheral blood. CTC was defined as positive when at least 1 tumor marker mRNA was detected.

RESULTS

CTC was positive in 34 patients (13.9%) before surgery and in 41 patients (16.8%) after the thoracic procedure. Multivariate analysis identified tumor depth (hazard ratio [HR], 0.439; 95% confidence interval [95% CI], 0.268-0.722; P = 0.0012), lymph node metastasis (HR, 2.467; 95% CI, 1.436-4.237; P = 0.0011), venous invasion (HR, 1.802; 95% CI, 1.082-3.002; P = 0.0236), and CTC status after the thoracic procedure (HR, 1.647; 95% CI, 1.032-2.629; P = 0.0365) as independent prognostic factors of disease-free survival. The rates of hematogenous (P = 0.0222) and local (P = 0.0464) recurrences were significantly higher in patients with CTC(+) after the thoracic procedure than those with CTC(-) after the thoracic procedure. Responders to neoadjuvant chemotherapy showed less lymphatic invasion and a decreased positive CTC rate after the thoracic procedure than nonresponders.

CONCLUSIONS

CTC status after the thoracic procedure is a useful predictor for hematogenous and local recurrences in patients with esophageal cancer.

Long term survival following the detection of circulating tumour cells in head and neck squamous cell carcinoma

BACKGROUND

Techniques for detecting circulating tumor cells in the peripheral blood of patients with head and neck cancers may identify individuals likely to benefit from early systemic treatment.

METHODS

Reconstruction experiments were used to optimise immunomagnetic enrichment and RT-PCR detection of circulating tumor cells using four markers (ELF3, CK19, EGFR and EphB4). This method was then tested in a pilot study using samples from 16 patients with advanced head and neck carcinomas.

RESULTS

Seven patients were positive for circulating tumour cells both prior to and after surgery, 4 patients were positive prior to but not after surgery, 3 patients were positive after but not prior to surgery and 2 patients were negative. Two patients tested positive for circulating cells but there was no other evidence of tumor spread. Given this patient cohort had mostly advanced disease, as expected the detection of circulating tumour cells was not associated with significant differences in overall or disease free survival.

CONCLUSION

For the first time, we show that almost all patients with advanced head and neck cancers have circulating cells at the time of surgery. The clinical application of techniques for detection of spreading disease, such as the immunomagnetic enrichment RT-PCR analysis used in this study, should be explored further.

Detection of survivin-expressing circulating cancer cells in the peripheral blood of patients with esophageal squamous cell carcinoma and its clinical significance

We previously demonstrated that the detection of circulating cancer cells (CCC) expressing survivin mRNA could provide valuable information for predicting recurrence in patients with breast, lung, gastric and colorectal carcinoma. The purpose of this study is to investigate whether the detection of survivin-expressing CCC in the peripheral blood is also useful for predicting recurrence in patients with esophageal squamous cell carcinoma (ESCC). Blood samples obtained from 108 ESCC patients and 75 healthy volunteers were quantitatively investigated by a technique that detected reverse transcription-polymerase chain reaction products based on a hybridization-enzyme linked immunosorbent essay. Not all of the patients were available for the follow-up study. Only 48 patients who were treated with similar adjuvant therapy regimens were available and followed-up for 33 months after the initial assay test. Survivin-expressing CCC were detected in 51 (47.2%) patients. The presence of survivin-expressing CCC was found to be significantly associated with depth of invasion, vascular invasion, nodal status, and disease stages (P = 0.032, 0.019, 0.018, and 0.001, respectively). During the follow-up period, patients who had positive survivin expressions had a higher relapse rate and a shorter survival time than those who had negative survivin expressions (P = 0.002 and 0.016, respectively). Examination of survivin-expressing CCC could provide valuable information in the prediction of haematogenous recurrence as well as in the prognosis of ESCC.

Circulating tumor cells in perioperative esophageal cancer patients: quantitative assay system and potential clinical utility

PURPOSE

To establish a quantitative system for evaluating the role of circulating tumor cells (CTC) in peripheral blood samples in patients who undergo surgery for treatment of esophageal cancer.

EXPERIMENTAL DESIGN

One hundred fifty-five peripheral blood samples from 53 esophageal cancer patients were collected before surgery (B-1), immediately after surgery (B0), and on the 3rd day postoperatively (B+3). Eighty-nine samples from 22 benign patients who underwent thoracotomy and 30 healthy volunteers were obtained as controls. A real-time reverse transcription-PCR quantitative analysis system based on carcinoembryonic antigen (CEA) mRNA gene expression was designed for detection of CTC.

RESULTS

This developed system can detect CEA mRNA-positive cells down to 3 cells per milliliter of peripheral blood. The cells in negative control groups were lower than the detection limit. The medians of 188 [95% confidence interval (95% CI), 155-498], 1513 (95% CI, 660-7,974) and 707 (95% CI, 737-3,005) CEA mRNA-positive cells per mL with the CEA-positive rates of 28.3%, 60.4%, and 42.9% in B-1, B0, and B+3 peripheral blood samples were obtained, respectively. There was statistically significant difference between B-1 and B0 (P=0.0001) and between B-1 and B+3 (P=0.0209). Fifty percent of patients with R>0.4 showed metastasis in 1 year after surgery, whereas the probability was only 14.3% for patients with R<0.4 (where R is CTC ratio of B+3 to B0, P=0.043).

CONCLUSIONS

Esophageal cancer operation results in tumor cells dissemination and significant increase of CTC in peripheral blood, which is related to the developed metastasis. CTC are helpful for evaluating micrometastasis and have the potential for predicting recurrence in esophageal cancer.

Epithelial molecular markers in the peripheral blood of patients with colorectal cancer

Despite the modest improvements in patient survival from colorectal cancer in the last few decades, the overall five-year survival rate remains at 40 to 45 percent. Surgical resection is the mainstay of treatment for colorectal cancer; however, nearly one-half of all patients who undergo a potentially curative resection will relapse because of undetected micrometastasis. The fact that the overall survival rate remains poor strongly suggests that the dissemination of these cells occurs early in the disease process and emphasizes the need for finding feasible diagnostic methods with sufficient sensitivity and specificity. The most commonly used technique for the detection of nucleic acid material of disseminated tumor cells is the polymerase chain reaction. We critically review the literature on DNA and messenger ribonucleic acid molecular markers that have been used for the detection of circulating tumor cells in the peripheral blood of patients with colorectal cancer and other solid tumors as appropriate for comparison. The cytokeratins, particularly cytokeratin 19 and cytokeratin 20, are the most investigated prognostic markers, but even for these questions remain about their clinical value, and hence most recent studies are utilizing a combination of factors. There is an urgent need for standardized isolation and analysis techniques to be adopted thus allowing large-scale, appropriately controlled, multicenter trials to be undertaken on the most promising candidate markers.

Optimal markers for real-time quantitative reverse transcription PCR detection of circulating tumor cells from melanoma, breast, colon, esophageal, head and neck, and lung cancers

BACKGROUND

The detection of circulating tumor cells (CTCs) may prove useful for screening, prognostication, and monitoring of response to therapy. However, given the large background of circulating cells, it is probably necessary to detect 1 cancer cell in >10(6) leukocytes. Although reverse transcription (RT)-PCR is potentially sensitive and specific enough to achieve this goal, success will require the use of appropriate mRNA markers. The goal of this study was to identify optimal marker combinations for detection of CTCs.

METHODS

An extensive literature and internet database survey was conducted to identify potential markers. We then used real-time quantitative RT-PCR to test for expression of selected potential markers in tissue samples from primary tumors of breast, colon, esophagus, head and neck, lung, and melanoma and normal blood samples. Markers with high expression in tumors and a median 1000-fold lower expression in normal blood were considered potentially useful for CTC detection and were tested further in an expanded sample set.

RESULTS

A total of 52 potential markers were screened, and 3-8 potentially useful markers were identified for each tumor type. The mRNAs for all but 2 markers were found in normal blood. Marker combinations were identified for each tumor type that had a minimum 1000-fold higher expression in tumors than in normal blood.

CONCLUSIONS

Several mRNA markers may be useful for RT-PCR-based detection of CTCs from each of 6 cancer types. Quantification of these mRNAs is essential to distinguish normal expression in blood from that due to the presence of CTCs. Few markers provide adequate sensitivity individually, but combinations of markers may produce good sensitivity for detection of the presence of these 6 neoplasms.

Carcinoembryonic antigen messenger RNA expression in blood predicts recurrence in esophageal cancer

PURPOSE

The clinical significance of isolated tumor cells (ITC) in blood has not been clearly established, particularly during follow-up in cancer patients. We conducted a longitudinal analysis of the relationship between ITC in blood during follow-up and clinicopathologic findings in patients with esophageal squamous cell carcinoma.

EXPERIMENTAL DESIGN

Blood samples obtained from 106 patients were examined by real-time RT-PCR assay targeting carcinoembryonic antigen (CEA) mRNA. Follow-up examination every 3 months after surgery included testing for CEA mRNA and tumor markers, as well as imaging.

RESULTS

Thirty-nine (36.8%) patients were positive for CEA mRNA expression. CEA mRNA positivity significantly correlated with tumor depth, lymph node metastasis, stage, and venous invasion. Recurrent disease was found in 34 of 106 (32.1%) cases. CEA mRNA was found in 28 (76.5%) patients experiencing relapse. Of these 28 patients, the number positive of CEA mRNA before detection by imaging, at the same time of detection by imaging, and after detection by imaging was 18 (52.9%), 8 (23.5%), and 2 (5.9%), respectively. The sensitivity, specificity, positive predictive value, and negative predictive value for CEA mRNA were higher than those for serum CEA or squamous cell carcinoma. Patients positive for CEA mRNA experienced significantly shorter disease-free interval than those with negative CEA mRNA (P < 0.001). According to multivariate analysis, CEA mRNA positivity was an independent factor for disease-free interval.

CONCLUSIONS

Examination of CEA mRNA in peripheral blood during follow-up is useful for early detection of occult recurrence. We believe that CEA mRNA in blood will be a new marker for recurrence in esophageal squamous cell carcinoma.

Chenodeoxycholic acid stimulates the progression of human esophageal cancer cells: A possible mechanism of angiogenesis in patients with esophageal cancer

Bile acids are known to promote the growth of gastrointestinal cancer. However, the underlying mechanism remains unclear. We examined whether bile acids induce tumor growth via the cyclooxygenase (COX)-2 angiogenic pathway. In vitro, esophageal squamous cell carcinoma (ESCC) cells and esophageal adenocarcinoma cells were studied. Production of prostaglandin E2 (PGE2) and vascular endothelial growth factor (VEGF) in response to treatment with chenodeoxycholic acid (CDCA) was assessed by enzyme-linked immunosorbent assay (ELISA). COX-2 protein and VEGF protein were measured by immunoblot analysis, and COX-2 activity was measured by ELISA. In vivo, CDCA was administered to ESCC cell-bearing mice. Tumor tissues were analyzed immunohistochemically, and microvessel density was evaluated. Clinically, 134 patients with ESCC who underwent esophagectomy were studied. In vitro, CDCA induced the production of PGE2 and VEGF in dose- and time-dependent manners, and these effects were attenuated by a selective COX-2 inhibitor, mitogen-activated protein kinases inhibitor, or epidermal growth factor receptor inhibitor. CDCA-induced COX-2 in the cell lysate increased the secretion of VEGF into the culture medium. In vivo, CDCA markedly enhanced tumor growth and increased vascularization. Clinically, patients whose tumors expressed both COX-2 and VEGF had poor outcomes. Our results suggest that bile acids, important constituents of duodenal fluid, stimulate the development of human esophageal cancer by promoting angiogenesis via the COX-2 pathway.

Squamous cell carcinoma-antigen messenger RNA level in peripheral blood predicts recurrence after resection in patients with esophageal squamous cell carcinoma

BACKGROUND

The aim of this study was to clarify whether preoperative squamous cell carcinoma-antigen messenger RNA (SCC-Ag mRNA) level in peripheral blood can be used to predict tumor recurrence after curative resection for esophageal squamous cell carcinoma.

METHODS

A prospective analysis was conducted for 46 consecutive patients who underwent curative esophagectomy and who had no residual tumor. The SCC-Ag mRNA level in the peripheral blood of each patient was measured preoperatively by using quantitative reverse transcriptase-polymerase chain reaction. Median follow-up period was 34 months.

RESULTS

Receiver operating characteristic analysis demonstrated that the optimal cutoff level of SCC-Ag mRNA was 40. Patients were divided into the high SCC-Ag mRNA level group (n = 14) and the low SCC-Ag mRNA level group (n = 32). The cumulative probabilities of tumor recurrence were higher in the high SCC-Ag mRNA level group (probability of recurrence was 71% at 2 years) than in the low group (22% at 2 years; P = .0005). SCC-Ag mRNA level (relative risk, 3.00; 95% confidence interval, 1.05-8.54; P = .040) was the strongest independent predictor of recurrence by multivariate analysis.

CONCLUSIONS

Preoperative SCC-Ag mRNA levels in the peripheral blood are the best predictive factor for recurrence in patients with esophageal squamous cell carcinoma who undergo curative resection (R0).

A Strategy for Determining Which Thoracic Esophageal Cancer Patients Should Undergo Cervical Lymph Node Dissection

BACKGROUND

There is controversy about performing cervical lymph node dissections in all middle and lower thoracic esophageal squamous cell carcinoma patients. The purpose of this study was to evaluate whether intraoperative examination of thoracic paratracheal lymph node by real-time reverse transcription-polymerase chain reaction was worthwhile for selecting patients for cervical lymph node dissection.

METHODS

Under informed consent, 30 middle and lower thoracic esophageal squamous cell carcinoma patients were examined for thoracic paratracheal lymph node metastasis intraoperatively by hematoxylin-eosin staining and real-time reverse transcription-polymerase chain reaction for messenger RNA encoding squamous cell carcinoma antigen. When thoracic paratracheal lymph node metastasis was found, cervical lymph node dissection was performed. If the patients had no thoracic paratracheal lymph node metastasis, a randomized study for selection of cervical lymph node dissection was performed.

RESULTS

Eleven of 30 patients with middle or lower third thoracic esophageal squamous cell carcinoma had thoracic paratracheal lymph node metastasis. Five of these 11 patients had cervical lymph node metastasis. Nineteen patients who had no metastasis in the thoracic paratracheal lymph nodes were enrolled in a randomized study. Eight of the 19 patients received cervical lymph node dissection and they were found not to have cervical lymph node metastasis. The other 11 patients did not receive cervical lymph node dissection, and there was no cervical lymph node recurrence.

CONCLUSIONS

The intraoperative diagnosis of metastasis in the thoracic paratracheal lymph node may be used as an indicator for cervical lymph node dissection in middle and lower thoracic esophageal cancer patients.