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