TAURAS - T790 AURA ScreenFailure SOC Registry Study

Inclusion Criteria: 1. Provision of informed consent from the patient or next-of-kin for deceased patient at study entry, where this is mandated/allowed by local regulations 2. Aged at least 18 years. Patients from Japan aged at least 20 years 3. Patients who have been considered ineligible for entry into the AZD9291 AURA3 registration trial as a result of their tumour not harbouring the T790M mutation, according to the cobas EGFR test of a biopsy taken following the latest line of therapy, at a central testing lab participating in the D5160C00003 (AURA3) study. 4. Patients who have undertaken or plan to undertake 2nd-line therapy after screen failure for the AURA3 study. Exclusion Criteria: 1. Treatment with any of the following: * Prior treatment with more than one line of systemic treatment for advanced disease prior to failing screening assessments for AURA3. * Major surgery (excluding placement of vascular access) within 4 weeks prior to failing screening assessments for AURA3. * Palliative radiotherapy with a limited field of radiation within 1 week prior to enrolment, with the exception of patients receiving radiation to more than 30% of the bone marrow or with a wide field of radiation which must be completed within 4 weeks prior to failing screening assessments for AURA3.. 2. Spinal cord compression or brain metastases unless asymptomatic, stable and not requiring steroids for at least 4 weeks prior to failing screening assessments for AURA3.. 3. Involvement in the planning and conduct of the study (applies to AstraZeneca staff or staff at the study site). 4. Judgment by the physician that the patient should not participate in the study if the patient is unlikely to comply with study procedures, restrictions and requirements. 5. Patients who are known to be entering an interventional clinical study (blinded, randomized or open label clinical study) at the time of the enrolment into this study. However, inclusion in this study does not preclude participation in any other clinical study after enrolment. Patients who participate in clinical studies after enrolment into this study will be followed up to the extent possible as permitted by the sponsor of that clinical study. 6. Patients with an invalid or unsuccessful T790M mutation test result during screening for AURA3.