How could we detect circulating tumor cells in lung cancer patients? A brief study by flow cytometry

Circulating tumor cells (CTCs) play a crucial role in the metastatic spread of carcinoma. Therefore, CTC has been interest of a subject in the past few decades in terms of prognosis and response to the therapy in several cancer diseases. Recent improvements in technical approaches maintain to identify CTCs from whole blood have demonstrated the potential value of CTC detection as a liquid biopsy especially in those tumors where tissue accessibility is often challenging as in lung cancer. Lung cancer is the most common cause of death from cancer worldwide in both men and women which is commonly metastasize before it is diagnosed. The aim of this study is to enumerate of CTCs in peripheral blood sample (7.5 mL) of lung cancer patients by flow cytometry. Our modified method which consists of enrichment and detection steps get involved in 9 patients with lung cancer and 9 healthy volunteers. We performed a density-based ficoll gradient centrifugation and a immunomagnetic separation technique (CD45 negative selection) for the enrichment step. Next, multi-parameter flow cytometry based on the expression of anti-epithelial cell adhesion molecule and cytokeratins was used to detect circulating tumor cells among enriched cells. According to our results, circulating tumor cells were not detected on healthy volunteers but circulating tumor cells were found in all of patients with lung cancer (Z=3.823; p