PS02.071: EVALUATION OF CIRCULATING TUMOR CELLS IN ESOPHAGEAL CANCER PATIENTS

Abstract

Abstract 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.