The impact of E‐cadherin expression on the prognosis of esophageal cancer: a meta‐analysis

E‐cadherin is a 120‐KD transmembrane calcium‐dependent cell adhesion protein that has been demonstrated drownregulated in a large amount of invasive tumors. However, its effect on the prognosis of esophageal cancer (EC) remains controversial. All the relevant English articles that reported survival data or clinicopathological parameters were enrolled in this meta‐analysis. A total of 24 studies, including 2691 cases, were included in this study. Twelve studies containing 1669 cases were enrolled to synthesize with hazard ratio (HR) and its 95% confidence interval (CI). The pooled HR for all 12 studies enrolled in this meta‐analysis was 1.33 (95% CI 1.16–1.52; z = 3.99, P = 0.00). When the study measured by enzyme‐linked immunosorbent assay is excluded, the pooled HR‐evaluated E‐cadherin to reduce the expression in EC, and in esophageal squamous cell carcinoma was 1.39 (95% CI 1.22–1.58; z = 5.08, P = 0.00) and 1.38 (95% CI 1.21–1.56; z = 4.87, P = 0.00), respectively. The risk of reduced E‐cadherin expression on poor differentiation degree was 1.636 (95% CI 1.33–2.02). The pooled odds ratio of reduced E‐cadherin expression on deeper tumor invasion, lymph node metastasis, and higher clinical stage were 2.63 (95% CI 1.75–3.94), 1.77 (95% CI 1.06 ?2.97), and 3.39 (95% CI 1.85–6.23). Reduced E‐cadherin expression detected by immunohistochemistry could be a valid prognostic marker in patients with EC, especially in patients with esophageal squamous cell carcinoma. Reduced E‐cadherin expression is significantly associated with poorer differentiation degree.     

Serum soluble E‐cadherin is a potential prognostic marker in esophageal squamous cell carcinoma

E‐cadherin is a well‐documented tumor suppressor with downregulated expression in many cancer types. Upon proteolytic cleavage, a soluble form of 80‐kDa degradation fragment, known as soluble E‐cadherin (s‐Ecad), is present in circulation; its level in sera of cancer patients is significantly associated with metastasis, recurrence, and prognosis in some malignancies. The present study investigated the association of s‐Ecad with clinicopathological characteristics of patients with esophageal squamous cell carcinoma (ESCC) and its prognostic significance. A cohort of 97 patients who underwent surgery alone (n= 56) or neoadjuvant chemoradiation therapy and surgery (CRT) (n= 41) was recruited for this study. Serum samples were collected at operation (surgery group) and pre‐ and post‐CRT treatment (CRT group) for measurement of s‐Ecad protein by enzyme linked immunosorbent assay. Serum s‐Ecad levels were correlated with clinicopathological parameters as well as survival. Univariate analysis showed no significant relationship between serum s‐Ecad level and clinicopathological parameters for all sets of samples. Survival analysis showed that in patients who had surgical resection only, those with s‐Ecad levels equal to or below the median value survived significantly longer than those with levels above the median (median survival 25.6 vs. 14.1 months, P= 0.012). Multivariate analysis showed that pathological N stage, M stage, R category, and serum s‐Ecad level were significant independent prognostic factors for ESCC patients who underwent surgery only. The hazard ratio for s‐Ecad was 1.104 (95% CI: 1.026–1.187) and P= 0.008. Serum s‐Ecad was detected in ESCC patients and its potential as an independent prognostic marker requires further investigation.     

Feasibility of endoscopic mucosal resection as salvage treatment for patients with local failure after definitive chemoradiotherapy for stage IB,II, and III esophageal squamous cell cancer

Local failure after definitive chemoradiotherapy (CRT) for stage IB, II, and III esophageal cancer is one of the causes of poor outcome. Endoscopic mucosal resection (EMR) is an effective treatment for superficial esophageal cancer. However, its feasibility as a salvage treatment for local recurrent or residual tumors after definitive CRT for stage IB, II, and III esophageal cancer remains unclear. Between January 2000 and February 2008, 274 patients with stage IB, II, and III esophageal squamous cell cancer excluding T4 received definitive CRT at the National Cancer Center Hospital, Japan. Of these patients, nine patients with local recurrence after achieving complete response and two patients with residual tumor underwent salvage EMR. The technique of salvage EMR involved a strip biopsy method. We retrospectively reviewed the 11 patients (13 lesions). Characteristics of all 11 patients were as follows: median age of 69 (range: 45–78); male/female: 10/1; baseline clinical stage (Union for International Cancer Control 7th) IB/IIA/IIB/III: 1/3/7/0. The depth of resected tumor was limited to the mucosal layer in seven lesions and submucosal in six lesions. En bloc resection was performed on six lesions (46%). The vertical margin was free of cancer cells in 11 lesions (84.6%). No major complications, such as hemorrhage requiring blood transfusion and perforation, were experienced. At a median follow‐up period of 38.9 months (range: 5.3–94 months) after salvage EMR, no recurrence was detected in six patients (54%). Local recurrence was detected in five patients (27%). Of these patients, two had lung metastasis simultaneously, and one was also detected lung metastasis 2 months after the detection of local recurrence. The 5‐year survival rate after salvage EMR was 41.6%. Salvage EMR is a feasible treatment option for local recurrent or residual lesions after definitive chemotherapy and/or radiotherapy for stage IB, II, and III esophageal squamous cell cancer.     

Low‐grade dysplasia component in early invasive squamous cell carcinoma of the esophagus

Background and Aims: It has not been determined whether low‐grade squamous dysplasia (LGD) of the esophagus is a precancerous lesion or not. If LGD progresses to squamous cell carcinoma, early carcinoma lesions that have such a natural history might contain a remaining LGD component. Methods: The lesions in the 68 patients with early invasive squamous cell carcinoma who underwent endoscopic mucosal resection were examined for the presence of an LGD component. If LGD components were observed, the degrees of architectural and cytological abnormalities of LGD components and those of tumor invasive fronts in the same lesions were studied. The degrees of abnormalities of 28 small LGD lesions were also studied. Results: Histological examination of resected specimens confirmed LGD components in 43% of the squamous cell carcinoma lesions. The lesions of lamina propria mucosae (m2) cancer contained a significantly broader area of LGD component than did the lesions of muscularis mucosae (m3) and submucosal layer (sm) cancer (P = 0.037). Mean score for the degrees of cytological abnormalities of LGD component was similar to that of tumor invasive front (P = 0.457) and significantly higher than that of small LGD lesions (P < 0.001). Conclusion: Our results indicate the possibility that the lesion was formed by a combination of small lesions that arose as a multicentric occurrence of squamous cell carcinoma and dysplasia. Our results also suggest that an LGD component would transform to carcinoma along with tumor progression. However, the concept of ‘basal cell layer type carcinoma in situ’ may be suitable for squamous cell lesions with a high degree of cytological abnormalities confined to the lower half of the epithelium.     

The mode of tumour progression in combined hepatocellular carcinoma and cholangiocarcinoma: an immunohistochemical analysis of E‐cadherin,alpha‐catenin and beta‐catenin

Abstract: Background/Aim: To investigate the mode of progression of combined hepatocellular carcinoma and cholangiocarcinoma (cHCC‐CC). Methods: An immunohistochemical study for E‐cadherin (ECD) and alpha‐ and beta‐catenins was performed on 29 cases of cHCC‐CC. Results: Reduced expression of ECD was significantly correlated with the tumour grade of the hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) components, intrahepatic metastasis (IM) of HCC, IM of CC, and vascular invasion of CC (p < 0.05, respectively). There was a significant relationship between the reduced expression of beta‐catenin and the tumour grade of HCC components (p < 0.05). Cases showing concurrent intrahepatic metastasis composed of HCC, CC, or both, numbered 6, 5, and 2, respectively. The expression patterns of ECD and beta‐catenin of IM were similar to those of primary lesion in most cases. On the other hand, expression of ECD and beta‐catenin of IM of HCC component were preserved, even though those of the primary sites were reduced in two cases and one case, respectively. ECD and beta‐catenin were significantly correlated with tumour differentiation and tumour progression. Conclusions: Preserved or recovered ECD and beta‐catenin expression may be of beneficial effect for re‐establishing the tissue architecture at the metastatic site.     

Utility of dysphagia grade in predicting endoscopic ultrasound T‐stage of non‐metastatic esophageal cancer

Patients with non‐metastatic esophageal cancer routinely undergo endoscopic ultrasound (EUS) for loco‐regional staging. Neoadjuvant therapy is recommended for ≥T3 tumors while upfront surgery can be considered for ≤T2 lesions. The aim of this study was to determine if the degree of dysphagia can predict the EUS T‐stage of esophageal cancer. One hundred eleven consecutive patients with non‐metastatic esophageal cancer were retrospectively reviewed from a database. Prior to EUS, patients' dysphagia grade was recorded. Correlation between dysphagia grade and EUS T‐stage, especially in reference to predicting ≥T3 stage, was determined. The correlation of dysphagia grade with EUS T‐stage (Kendall's tau coefficient) was 0.49 (P < 0.001) for the lower and 0.59 (P = 0.008) for the middle esophagus. The sensitivity and specificity of dysphagia grade ≥2 (can only swallow semi‐solids/liquids) for T3 cancer were 56% (95% confidence interval [CI] 43–67%) and 93% (95% CI 79–98%), respectively. The sensitivity, specificity, and positive predictive value of dysphagia grade ≥3 (can only swallow liquids or total dysphagia) for T3 lesions were 36% (95% CI 25–48%), 100% (95% CI 89–100%), and 100% (95% CI 83–100%), respectively. Overall, there was a significant positive correlation between dysphagia grade and the EUS T‐stage of esophageal cancer. All patients with dysphagia grade ≥3 had T3 lesions. This may have clinical implications for patients who can only swallow liquids or have complete dysphagia by allowing for prompt initiation of neoadjuvant therapy, especially in countries/centers where EUS service is difficult to access in a timely manner or not available.     

Clinicopathological significance of cyclooxygenase‐2 and cell cycle‐regulatory proteins expression in patients with esophageal squamous cell carcinoma

The aim of this study was to examine the expression of the molecular markers cyclooxygenase‐2 (COX‐2), Ki‐67, cyclin A, and p27 in patients with esophageal squamous cell carcinoma (ESCC), to ascertain the relationship of these makers with the clinicopathological significance of the patients, and to assess the additional prognostic value of the expression profile of these proteins for ESCC patients. The expression levels of COX‐2, Ki‐67, cyclin A, and p27 proteins of a series of primarily resected ESCC samples were determined by immunohistochemistry method. Clinicopathological and molecular factors affecting survival were analyzed by multivariate analysis. A total of 78 specimens were included in this study. Expression of COX‐2 was observed in 43 (55.1%) cases, and high levels of expression of Ki‐67, p27, and cyclin A were observed in 57 (73.0%), 33 (42.3%), 43 (55.1%) cases, respectively. The results of univariate survival analysis indicated that more advanced tumor stage, lymph node involvement, systemic dissemination, the levels of expression of COX‐2, Ki‐67, cyclin A, and p27 were associated with survival (all P‐value < 0.05). Multifactorial survival analysis revealed that only lymph node involvement, over‐expression of cyclin A, and low p27 expression were associated with the survival of the patients (hazard ratios = 2.83, 4.7, 2.9, respectively; P= 0.025, 0.042, 0.005, respectively). Among the molecular markers assessed, the expression of cell proliferation markers cyclin A and p27 are independent prognostic factors in patients with ESCC, whereas neither COX‐2 nor Ki‐67 is of independent prognostic value.     

Expression of p53, p16 and cyclooxygenase-2 in esophageal cancer with tissue microarray

OBJECTIVE: The aim of this study was to obtain a comprehensive survey on the expression of p53, p16 and cyclooxygenase‐2 (COX‐2) in esophageal cancer progression and their clinical significance. METHODS: A tissue microarray containing 86 specimens from esophageal cancer and 40 specimens from adjacent non‐cancer tissue was constructed to survey the expression of p53, p16 and COX‐2 by immunohistochemistry. The influence of each biomarker on the histotype of esophageal lesion was assessed by logistic regression analysis. RESULTS: The expression of p53 and COX‐2 was significantly higher in tumorous tissue than in non‐tumorous tissue. As to p16, no significant difference was detected between tumorous and non‐tumorous tissue. A significant correlation was observed among p53, COX‐2 and p16 expression. Logistic regression analysis revealed that the risk factors of a tumorous histotype were the positive expression of p53 (odds ratio [OR] = 18.214) or COX‐2 (OR = 42.703), and no reciprocal relationship to neoplastic progression was recognized with p53, p16 and COX‐2. CONCLUSIONS: p53 and COX‐2 were independent predictors in esophageal carcinogenesis. Esophageal tissue with a positive expression of p53 or COX‐2 was more likely to develop esophageal cancer.     

Clinical effect of E‐series of prostaglandin receptor 2 and epidermal growth factor receptor signal pathways in the development of esophageal squamous cell carcinoma

Signal pathways mediated by epidermal growth factor receptor (EGFR) and E‐series of prostaglandin receptors (EPs) are closely correlated to the pathogenesis of tumor. This experiment was designed to investigate the expression and clinical significance of EP2 and EGFR in esophageal squamous cell carcinoma (ESCC). Tissue samples were collected reterospectively from 87 patients with ESCC (first diagnosed). The patients were followed up for 5 years after radical surgery. The expression of EP‐2 and EGFR were examined by tissue chip technology and immunohistochemistry methods. Clinicopathological and prognostic impact were evaluated. Overexpression of EGFR and EP‐2 was more observed in ESCC than the control group (58.6% vs. 13.9%; 52.9% vs. 4.88%, P < 0.001, respectively); which correlated with tumor infiltration depth, lymph node metastasis, and tumor‐lymph node‐metastasis staging. Both the EP‐2 and EGFR overexpression were detected in 39 specimens and exhibited the positive correlation (P < 0.001, r = 0.404). Overexpression of EP2 and EGFR exhibited significant correlation with worse 5‐year overall survival than those with negative result (17.6% vs. 27.8%, P = 0.011; 10.9% vs. 34.1%, P < 0.001, respectively). Cox proportional hazard model showed that the T‐staging, lymph node metastasis, and EGFR overexpression were the independent risk factors of the prognosis. The present study exhibited that the overexpression of EP2 and EGFR in ESCC tissues might play an important role in carcinogenesis and the progression of ESCC.     

The expression of CXCR4 and its relationship with matrix metalloproteinase‐9/vascular endothelial growth factor in esophageal squamous cell cancer

Esophageal cancer (EC) is a highly aggressive neoplasm with poor prognosis. The main reason for this disappointing outcome is the strong behavior of esophageal cancer cell's invasion and metastasis. CXC chemokine receptor 4 (CXCR4) was found to be expressed in many tumors and significantly correlated with invasion, angiogenesis, metastasis, and prognosis. In the present study, we investigated the expressions of CXCR4, matrix metalloproteinase‐9 (MMP‐9), and vascular endothelial growth factor (VEGF) in esophageal squamous cell cancer (ESCC) and analyzed the relationship among the three proteins. Sections of paraffin‐embedded tissues were obtained from 127 patients with ESCC undergoing esophagectomy at Zhongshan Hospital, Fudan University in 2005. The CXCR4, MMP‐9, and VEGF expressions in EC tissues were evaluated according to the immunohistochemical staining area and intensity. The correlations between patients' prognosis and covariates were analyzed by Kaplan–Meier method (univariate analysis) and Cox regression (multivariate analysis). The overall expression rate of CXCR4, MMP‐9, and VEGF was 88.2%, 93.7%, and 79.5%, respectively. CXCR4 expression was significantly associated with tumor grade, tumor size, tumor depth, regional lymph node metastasis, and tumor, node, metastasis (TNM) stage (P < 0.05). MMP‐9 expression was significantly associated with age and tumor grade (P < 0.05). VEGF expression was significantly associated with tumor grade, tumor depth, and TNM stage (P < 0.05). CXCR4 expression was positively correlated with MMP‐9 expression (P < 0.01, r= 0.365) and VEGF expression (P < 0.01, r= 0.380). However, there was no significant correlation between MMP‐9 and VEGF expression (P > 0.05). In univariate analysis, CXCR4 expression, tumor size, tumor depth, lymph node metastasis, and TNM stage were correlated with patients' prognosis (P < 0.05); in multivariate analysis, tumor size and lymph node metastasis were the independent factors of poor prognosis. CXCR4 was highly expressed in ESCC and correlated with MMP‐9, VEGF, clinicopathological features and prognosis. We speculated CXCR4 play an important role during the progression of this disease and there might be some regulatory mechanism existing between CXCR4 and MMP‐9/VEGF in ESCC.     

A health‐risk appraisal model and endoscopic mass screening for esophageal cancer in Japanese men

A strong association between inactive aldehyde dehydrogenase‐2 (ALDH2) and risk of esophageal cancer has been demonstrated in East Asian drinkers. An alcohol flushing questionnaire asking about past and current tendency for facial flushing to occur after drinking a glass (≈180 mL) of beer predicts the presence of inactive ALDH2 among Japanese aged 40 years or older with a sensitivity and specificity of approximately 90%. We invented a health‐risk appraisal (HRA) model that makes it possible to identify Japanese men who are at high risk for esophageal cancer based on their past and current alcohol flushing tendency, drinking, smoking, and intake of vegetables and fruits. Between 2008 and 2009, 2221 Japanese men aged 50 years or older filled out the HRA questionnaire before undergoing a screening examination by upper gastrointestinal endoscopy at five medical facilities. The endoscopic examination resulted in a diagnosis of esophageal cancer in 19 subjects, and 117 (5.27%) subjects had an HRA score ≥11. The proportion of subjects with an HRA score ≥11 was higher in the 50–69 age group (6.11–6.88%) than in 70–89 age group (2.84–2.86%). The esophageal cancer detection rate was 4.27% among the subjects with an HRA score ≥11 and only 0.67% among the other subjects. Based on a receiver operating characteristic curve analysis, when an HRA score of ≥9 was used for subjects aged 50–69 years and of ≥8 for those aged 70–89 years as the cutoff value to select individuals with a high risk for esophageal cancer, its sensitivity and false‐positive rate was 52.6% and 15.2%, respectively, and the cancer detection rate was 2.91% in the high‐risk group, as opposed to 0.48% in the other group. In conclusion, the high detection rates for esophageal cancer in the high‐risk groups encouraged screening based on our HRA model in larger Japanese populations.     

Comparative study between endoscopic ultrasonography and positron emission tomography‐computed tomography in staging patients with esophageal squamous cell carcinoma

Treatment strategy of esophageal cancer mainly depends on accurate staging. At present, no single ideal staging modality is superior to another in preoperative tumor‐node‐metastasis (TNM) staging of patients with esophageal cancer. We aimed to investigate the efficacy of endoscopic ultrasonography (EUS) and positron emission tomography‐computed tomography (PET‐CT) for staging of esophageal cancer. We retrospectively studied 118 consecutive patients with esophageal squamous cell carcinoma who underwent esophagectomy with or without neoadjuvant chemoradiotherapy (CRT) over a near 3‐year period between January 2005 and November 2008 at a tertiary hospital in Taiwan. Patients were separated into two groups: without neoadjuvant CRT (group 1, n= 28) and with CRT (group 2, n= 90). Medical records of demographic data and reports of EUS and PET‐CT of patients before surgery were reviewed. A database of clinical staging by EUS and PET‐CT was compared with one of pathological staging. The accuracies of T staging by EUS in groups 1 and 2 were 85.2% and 34.9%. The accuracies of N staging by EUS in groups 1 and 2 were 55.6% and 39.8%. The accuracies of T and N staging by means of PET‐CT scan were 100% and 54.5% in group 1, and were 69.4% and 86.1% in group 2, respectively. In group 2, 38 of 90 patients (42.2%) achieved pathologic complete remission. Among them, two of 34 (5.9%) and 12 of 17 (70.6%) patients were identified as tumor‐free by post‐CRT EUS and PET‐CT, respectively. EUS is useful for initial staging of esophageal cancer. PET‐CT is a more reliable modality for monitoring treatment response and restaging. Furthermore, the accuracy of PET‐CT with regard to N staging is higher in patients who have undergone CRT than those who have not.     

Endoscopic ultrasound‐guided fine needle aspiration biopsy in esophageal and mediastinal diseases: Clinical indications and results

Background: Endoscopic ultrasound‐guided fine needle aspiration biopsy (EUS‐FNAB) was developed to attain endosonographical images in real time in endoscopic biopsy, just like in percutaneous biopsy with ultrasonic or computer‐tomographical images. The results of EUS‐FNAB in esophageal and mediastinal diseases were evaluated and clinical indications of this technique were investigated. Methods: The study was performed in 58 patients, consisting of 30 with esophageal or mediastinal tumors and 28 requiring mediastinal lymph node examination. The instruments were linear array EUS transducer PEF‐703FA (Toshiba‐Fujinon, Tokyo, Japan) and 21G Endosonopsy (Hakko Shoji, Tokyo, Japan). The aspirated material was recovered on a filter paper and was formalin‐fixed to be examined histopathologically. Results: The tumors measured 6–60 mm (mean 29 mm). Collection of tissue was successful in 95% of the patients, and diagnostic accuracy was 95%. The biopsy specimen was satisfactory to establish histological diagnosis in every case of 27 patients with malignant diseases. No complication was experienced. Conclusion: The EUS‐FNAB is indicated in cases where the technique of EUS‐guided puncture is required, or is considered optimum in view of the safety and in cases where histological diagnosis is critical for the decision of treatment program. In many cases of mediastinal diseases, not even a detection of lesion is feasible without this technique, let alone a collection of tissue. The EUS‐FNAB is thus performed as a first choice of examination to obtain biopsy specimen in such cases. Endoscsopic ultrasound‐guided lymph node puncture is applied in order to assess the appropriateness of endoscopic mucosal resection (EMR) in patients with esophageal cancer, to follow up the patients after EMR and chemoradiotherapy (CRT), and to evaluate the efficacy of neoadjuvant CRT.     

Autoantibody detection to tumor‐associated antigens of P53, IMP1, P16, cyclin B1, P62, C‐myc,Survivn, and Koc for the screening of high‐risk subjects and early detection of esophageal squamous cell carcinoma

The aim of this study was to evaluate the diagnostic values by detecting sera autoantibodies to eight tumor‐associated antigens (TAAs) of P53, IMP1, P16, cyclin B1, P62, C‐myc, Survivn and Koc full‐length recombinant proteins for the screening of high‐risk subjects and early detection of esophageal squamous cell carcinoma (ESCC). Enzyme‐linked immunosorbent assay was used to detect autoantibodies against the eight selected TAAs in 567 sera samples from four groups, including 200 individuals with normal esophageal epithelia (NOR), 214 patients with esophageal basal cell hyperplasia (BCH), 65 patients with esophageal dysplasia (DYS), and 88 patients with ESCC. In addition, the expression of the eight antigens in esophageal tissues was analyzed by immunohistochemistry. Statistically significant distribution differences were identified among the four groups for each of the individual autoantibodies to six TAAs (P53, IMP1, P16, cyclin B1, P62, and C‐myc); the detection rates of antoantibodies were positively correlated with the progression of ESCC. When autoantibody assay successively accumulated to six TAAs (P53, IMP1, P16, cyclin B1, P62, and C‐myc), a stepwise increased detection frequency of autoantibodies was found in the four sera groups (6% in NOR, 18% in BCH, 38% in DYS, and 64% in ESCC, respectively), the risks to BHC, DYS, and ESCC steadily increased about 3‐, 9‐, and 27‐folds. The sensitivity and the specificity for autoantibodies against the six TAAs in diagnosing ESCC reached up to 64% and 94%, respectively. The area under the receiver operating characteristic curve for the six anti‐TAA autoantibodies was 0.78 (95% confidence interval 0.74–0.83). No more increasing in sensitivity was found with the addition of new anti‐TAA autoantibodies. A combination detection of autoantibodies to TAAs might distinguish ESCC patients from normal individuals and the patients with esophageal precancerous lesions.     

CXCR4 heterogeneous expression in esophageal squamous cell cancer and stronger metastatic potential with CXCR4‐positive cancer cells

CXCR4 belongs to a family of G protein‐coupled cell surface receptors and has been proved to a prognostic marker in a various tumors, including esophageal squamous cell cancer. In this study, we analyzed CXCR4 expression in tumor tissue and metastatic tumor tissues of lymph node by immunohistochemistry. CXCR4 was found to be an independent factor of patients' survival and heterogeneously expressed in tumor tissues. Compared with the primary tumor tissues, the scores of CXCR4 expression were significantly higher in corresponding metastatic tumor tissues of lymph nodes (P < 0.01). It was suggested CXCR4‐positive cells were prone to migrate to lymph nodes. In the further experiments in vitro, we confirmed heterogeneous expression of CXCR4 in esophageal squamous cell cancer cell lines (KYSE70, Ec109, and CaES17) by flow cytometry analysis. Meanwhile, two subpopulations were isolated from Ec109 based on CXCR4 membrane expression by fluorescence‐activated cell sorting. CXCR4‐positive cells showed stronger migration ability in Boyden chamber assay than CXCR4 negative ones (P < 0.01). However, no significant difference of cell proliferation was found between the two subpopulations in colony formation assay (P > 0.05). We concluded that CXCR4 might be a key molecule in esophageal squamous cell cancer metastasis.     

Immunohistochemical study of nuclear factor‐κB expression in esophageal squamous cell carcinoma: prognostic significance and sensitivity to treatment with 5‐FU

Nuclear factor‐κB (NF‐κB) is expressed in many types of cancers. It has been suggested that the expression of NF‐κB is associated with poor prognosis and resistance to chemoradiation therapies. This study evaluated the relationship between the expression of NF‐κB and the prognosis and sensitivity of esophageal squamous cell carcinoma (ESCC) to chemotherapy. One hundred and nine ESCC specimens, from patients who had undergone radical esophagectomy, were divided into two groups depending on the expression of NF‐κB. Surgical data and prognosis were compared between the two groups. NF‐κB‐positive tumors were detected in 61.5% of the cases. In 69 patients with stage II and III disease, 41 patients who were NF‐κB‐positive showed poor survival. The sensitivity of esophageal squamous cell carcinoma cell lines to 5‐fluorouracil (5‐FU) was analyzed by their NF‐κB expression, and the effect of 5‐FU was evaluated on the proliferation and activity of two cell lines of cultured ESCCs expressing NF‐κB. ESCCs with activated NF‐κB had poor sensitivity to 5‐FU. These results suggest that the increased expression of NF‐κB is associated with poor prognosis in patients with ESCC. NF‐κB may be a target for ESCC therapy because of its selective expression in this type of cancer.