The percentage of patients benefiting from immunotherapy is quite low and their systemic side effects can sometimes be severe. One of the main difficulties is to identify before treatment patients who will respond to immune checkpoint inhibitors. Currently, the selection is done in a very large majority of cases on the expression of PD-L1 by the tumor. But this biomarker is not sufficient to identify patients responding or not to immune checkpoint inhibitors. In addition, factors extrinsic to the tumor, to its microenvironment and patient immunity may be involved in the response to immunotherapy such as the microbiota.~The investigators therefore assume that the immune response in place during immunotherapy treatment differs according to the profile of patient response to immunotherapy.~The main objective of this project is to describe local and systemic anti-tumor immune system of patients responders or not to immune checkpoint inhibitors, but also whether the immunological characterization of sputum could be a reflection of the microenvironment tumor. The secondary objective is to study the intestinal microbiota tract of patients receiving immunotherapy, depending on their consumption of antibiotics, and compare it to the pulmonary microbiota.
Prospective pathophysiological exploratory monocentric study, focusing on adult patients with non-small cell lung cancer (NSCLC) : non-squamous type without oncogenic addiction, metastatic, treated with immune checkpoint inhibitors alone or in combination with chemotherapy in front line at the CHRU de Tours, France.