This is a multicentre, non-interventional, prospective study to be carried out in representative oncology departments / institutions in order to determine the prevalence of EGFR mutations in treatment-naive Russian patients with cytologically verified advanced NSCLC in Russia.

This is a multicentre, non-interventional, prospective study to be carried out in representative oncology departments / institutions in order to determine the prevalence of EGFR mutations in treatment-naive Russian patients with cytologically verified advanced NSCLC in Russia. No additional procedures besides those already used in the routine clinical practice will be applied to the patients. Treatment assignment will be done according to the current practice.

It is planned to enrol approximately 300 subjects in Russian Federation. Approximately 60 EGFR m+ (mutation-positive) patients will be followed for 1.5 years.

EGFR mutations rate before treatment in cytology and plasma samples in treatment-naive patients with advanced NSCLC in Russia is considered as the primary outcome variable in this study.

Inclusion Criteria:

• Cytologically verified advanced (stages IIIB - IV) nonsquamous (adenocarcinoma, large cell carcinoma) and mixed subtypes of NSCLC and NSCLC-NOS), diagnosed before enrolment into the study
• Quality and quantity of the cytological sample material meeting the requirements of the molecular-genetic testing
• No previous/ ongoing treatment for NSCLC at the moment of recruitment

Exclusion Criteria:

• Squamous NSCLC cytologically confirmed subtype of cancer
• Any medical condition which on the opinion of the investigator may interfere the patient's participation in the study
• Quality and quantity of the cytological sample material insufficient for the molecular-genetic testing

Target study population will be treatment-naive patients of both sexes, 18 years and older, with cytologically-verified advanced (stage IIIB-IV) non-squamous, mixed subtypes of NSCLC and NSCLC-NOS (Non-Small Cell Lung Cancer - Not Otherwise Specified), diagnosed before enrolment into the study, consented to participate in this non-interventional study, who visit the oncology hospitals/departments in the Russian Federation.