This large multinational, non-interventional study (NIS), will retrospectively collect data derived from established medical records over a period of up to approximately 6 years (2013 to 2018), building a platform to capture and consolidate information on treatment patterns, Overall Survival (OS) and treatment effectiveness outcomes in the real-world setting.

This is multi-centre, multicountry, longitudinal cohort of patients with primary stage III NSCLC (Non-small Cell Lung Cancer), identified through the review of established patient medical records. Patients diagnosed with primary stage III NSCLC between 01 January 2013 and 31 December 2017 will be targeted for study inclusion, allowing at least 9 months of follow-up for living patients recruited at last day of the enrolment window. It is estimated that a total of approx. 2000 patients from 15-20 countries (approax.)

Patients' demographic and clinical characteristics and treatment patterns will be described. Clinical outcomes such as Progression-Free Survival (PFS), Time to Progression (TTP), Objective Response Rate (ORR) and Disease Control Rate (DCR) will be described by Line of Therapy (LOT). Overall survival will be described, where available. Healthcare resource utilisation will be described, as available from medical records.

Inclusion Criteria:

1. Provision of informed consent by the patient or next of kin/legal representative (for deceased patients at study entry, unless a waiver was granted), according to local regulations
2. Adult male or female (≥18 years old or according to age of majority as defined by local regulations)
3. First ever diagnosis of lung cancer (absence of previous diagnosis of lung cancer, including small cell lung cancer [SCLC] and NSCLC) in the patient's medical records
4. Primary diagnosis of stage III NSCLC, confirmed by pathology, between 01 January 2013 and 31 December 2017
5. Available medical records

Exclusion Criteria:

1. Patients with a concomitant cancer at the time of diagnosis of stage III NSCLC, except for non-metastatic non-melanoma skin cancers or in situ or benign neoplasms. A cancer will be considered concomitant if it occurs within 5 years of NSCLC diagnosis
2. Patients initially diagnosed with stage I-II NSCLC who have progressed to stage III

stage III non-small-cell lung cancer patients