Schéma : OBSTINATE is an observational, prospective, national, multicentric study conducted in patients newly diagnosed with an unresectable stage III NSCLC (with exclusion of early stages NSCLC classified to pathological stage III).

OBSTINATE is a study planned to include 450 patients between 50 to 70 GFPC-affiliates or GFPC-associated centers approximately. All centers are located in France. The participating Site Investigators will be treating physicians within one of the participating centers.

After screening for eligibility checks, patients will receive the Patient Information Note from the Site Investigators. This Patient information Note will describe the study purpose and modalities. Patients who meet the eligibility criteria and do not oppose to data collection will be enrolled. The schedule of the medical visits in the study center will depend on the patient and his/her routine clinical care Protocol-relevant data will be collected by the treating physician within each center, for up to 5 years following the last patient's enrollment in the study.

Patients included in the study will complete the self-assess questionnaires at enrollment and during routine care follow-up, according to pre-specified data collection schedule.

Usual practices or modalities of follow-up of patients will remain unchanged compared to the current clinical practice as the study is designed to provide descriptive summary information.