Inclusion Criteria:  1. Adult male or female (≥18 years old or according to the age of majority as defined by local regulations).  2. First-ever diagnosis of lung cancer (absence of previous diagnosis of lung cancer, including SCLC and NSCLC) in the patient's medical records.  3. Patients either diagnosed with a primary diagnosis of SCLC (extensive or limited) or stage III NSCLC, confirmed by pathology, between 1st of January 2015 and 31st of December 2019.  4. Medical records available at the participating site reflect at least nine months of follow-up from the index date (unless the patient died within the first nine months of diagnosis)  Exclusion Criteria:  1. Patients with concomitant cancer at the time of diagnosis other than SCLC or stage III NSCLC, except for non-metastatic non-melanoma skin cancers, or in situ or benign neoplasms. Cancer will be considered concomitant if it occurs within five years of NSCLC or SCLC diagnosis 2. Patients initially diagnosed with stage I to II NSCLC who have progressed to stage III 3. Current or prior use of "Durvalumab" treatment