Osimertinib in Treating Participants With Stage I-IIIA EGFR-mutant Non-small Cell Lung Cancer Before Surgery

Inclusion Criteria: * Males and females \>=18 years of age * Histologically or cytologically confirmed non-small cell lung cancer (NSCLC), performed on a biopsy that occurred within the last 90 days. This biopsy can be deferred if the procedure is deemed to represent an unacceptable safety risk to the patient by the Principal Investigator and as long as the patient has a prior biopsy showing non-small cell lung cancer. * Documented activating EGFR mutation (Exon 19 deletion, T790M, or L858R) on tumor samples by Clinical Laboratory Clinical Laboratory Improvement Amendments (CLIA)-approved test * Patients treated with osimertinib or another EGFR tyrosine kinase inhibitors (TKI) (including erlotinib, afatinib, gefitinib, \& rocelitinib) are eligible if they received no more than 28 days of treatment, and if there is no evidence of grade 2 or greater treatment adverse events possibly related to treatment with the EGFR TKI. * Positron emission tomography (PET)-computed tomography (CT) within the last 60 days showing radiographic stage I to IIIa lung cancer (mediastinal staging biopsy is allowed but not required) * Brain magnetic resonance imaging (MRI) (or CT if contraindication to MRI) within the last 60 days showing no evidence of metastatic disease * Documentation that the patient is a candidate for surgical resection of their lung cancer by an American Board of Thoracic Surgery certified surgeon * The patient must have a tumor size \>=1 centimeter (cm) in its longest diamete…