Early Assessment of Response to Treatment of Metastatic LUng Tumors Based on CIrculating Tumor DNA

Inclusion Criteria: * Metastatic or locally advanced non-small cell lung cancer (stage III or IV) * At least one measurable target according to RECIST criteria * Identification of at least one molecular alteration in the tissue sample analyzed in the framework of patient management * Performance Status 0 to 2 * Affiliated to a social security system * Patient who can be followed under the protocol * Patient agreed to participate in the study and gave his/her express consent Exclusion Criteria: * Minor * Small cell or mixed bronchial cancer * Radiotherapy (except radiotherapy for antalgic purposes) during the last 7 days * Patient who has already started a first line of treatment * Patient already included in an interventional research protocol that may have an impact on the results of the ELUCID study * History of cancer (with the exception of non-melanoma skin, cervical cancer in situ, adequately treated) with sign of illness during the last 5 years * Patient which, does present a substantial risk of recurrence. * Major under guardianship, curators or deprived of liberty * Pregnant or lactating woman, or of childbearing age without effective contraception * Not affiliated to a social security system * Inability to understand the protocol and / or to give express consent