Additional Study Information: The purpose of this study is to see whether the medication osimertinib (TAGRISSOTM) alone or when used in combination with chemotherapy is more effective than chemotherapy alone for the treatment of early stage Non-Small Cell Lung Cancer prior to surgery. Osimertinib is an EGFR TKI therapy that targets EGFR mutations. When a tumor is found to have this type of mutation, there is a class of drugs known as EGFR tyrosine kinase inhibitors (TKIs) which target the mutation to treat the patient.