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Background Circulating tumor cells (CTCs) in patients with malignant tumors can be used as a prognostic marker. Recently the existence of mesenchymal CTCs have been detected by new methods. However, it has been not yet clarified how CTCs are associated with the treatment effects in esophageal cancer patients. We assessed CTCs in esophageal cancer patients and investigated the relationship between CTCs and treatment effect. Methods Seven patients who had potential of curative resection have been enrolled and peripheral blood samples (10ml) were collected before and after treatment. All patients received chemotherapy (5-FU and cisplatin) and four patients of them received as neoadjuvant therapy. Other patients received only chemotherapy and radiation therapy without operation. CTCs were analyzed using a Microfluidic Chip devise provide with the Nihon Gene Research Laboratories. This system can isolates CTCs from blood samples, based on their size and deformability differences from blood cells. Phenotypes of CTCs are determined by staining and scanning systems. A previous report revealed that this method had higher sensitivity for CTCs than conventional methods (the Cell Search system) in 61 metastatic breast cancer. Results Treatments effects were stable disease or better in all cases. Multiple CTCs were detected in all cases before treatment. Five patients had epithelial CTCs and others had only mesenchymal CTCs. Total number of CTCs after treatment whose data can be available decreased except for two cases. One patient had no CTC after treatment. Two cases have been currently analyzing. Conclusion CTCs may exist almost all patients of Stage II or more esophageal cancer. Decreasing the number of CTCs after treatment suggests some relationship between CTCs and treatment effect, and the accumulation of more cases is necessary. Disclosure All authors have declared no conflicts of interest. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the role of N-myc downstream-regulated gene 1 (NDRG1) expression in prognosis and survival of colorectal cancer patients with different ethnic backgrounds., Methods: Because NDRG1 is a downstream target of p53 and hypoxia inducible factor-1 alpha (HIF-1 alpha), we examined NDRG1 expression together with p53 and HIF-1 alpha by immunohistochemistry. A total of 157 colorectal cancer specimens including 80 from Japanese patients and 77 from US patients were examined. The correlation between protein expression with clinicopathological features and survival after surgery was analyzed., Results: NDRG1 protein was significantly increased in colorectal tumor compared with normal epithelium in both Japanese and US patient groups. Expression of NDRG1 protein was significantly correlated with lymphatic invasion, venous invasion, depth of invasion, histopathological type, and Dukes' stage in Japanese colorectal cancer patients. NDRG1 expression was correlated to histopathological type, Dukes' stage and HIF-1 alpha expression in US-Caucasian patients but not in US-African American patients. Interestingly, Kaplan-Meier survival analysis demonstrated that NDRG1 expression correlated significantly with poorer survival in US-African American patients but not in other patient groups. However, in p53-positive US cases, NDRG1 positivity correlated significantly with better survival. In addition, NDRG1 expression also correlated significantly with improved survival in US patients with stages III and IV tumors without chemotherapy. In Japanese patients with stages II and III tumors, strong NDRG1 staining in p53-positive tumors correlated significantly with improved survival but negatively in patients without chemotherapy., Conclusion: NDRG1 expression was correlated with various clinicopathological features and clinical outcomes in colorectal cancer depending on the race/ethnicity of the patients. NDRG1 may serve as a biological basis for the disparity of clinical outcomes of colorectal cancer patients with different ethnic backgrounds.