In the management of non-small cell lung cancer of the adenocarcinoma type, different therapeutic strategies can be proposed. These strategies are defined according to the results of a biological analysis of blood and/or tissue samples from the lung tumor. Mutations in the tumor DNA are sought. Thus, patients with sensitizing mutations can benefit from a treatment with a 3rd generation tyroine kinase inhibitor (TKI) whose efficacy has been widely demonstrated. Patients without tumor mutations will not benefit. However, resistance to TKIs appears after a certain time, often linked to the appearance of new mutations in the tumor. For this reason, blood biologic analyses are regularly performed to search for the emergence of resistance mutations and to propose a therapeutic alternative as soon as possible.

These analyses are performed routinely in the laboratory. In the course of these analyses, the investigators have identified conventional mutations but also new mutations not previously described in the literature.

Our objective is to list all the molecular abnormalities revealed during blood biological analyses, to determine their frequency and to study whether certain abnormalities can be linked to resistance to TKI.

Inclusion Criteria:

• advanced non-small cell lung cancer stage IIIB/IV
• Documentation of activating EGFR mutations (exon 19 deletions or exon 21 L858R substitution mutations) at the time of initial diagnosis
• Patient may receive up to one line of third EGFR TKI
• Plasma sample testing performed to detect EGFR TKI resistance

Exclusion Criteria:

• Patients have other concurrent cancers
• Patients who are not eligible receive TKI

Patients with metastatic adenocarcinoma