PDL-1 Expression on Circulating Tumor Cells in Non-small Cell Lung Cancer

"* Isolation of circulating tumor cells from 2 tubes by ISET filtration module. Peripheral blood samples will be collected for CTC analysis within 7 days before commencing treatment (defined as baseline) and following four cycles of immunotherapy,~* Analysis of PD-L1 and PD-L2 expression by immunocytochemistry on CTC~* Analysis of the expression of PD-L1, PD-L2 , CTLA4 on the histological specimen by immunohistochemistry"