Changes in Circulating Tumor-Specific DNA in Patients With Non-Metastatic Non-Small Cell Lung Cancer

Inclusion Criteria: * Patients with histologically confirmed or clinically suspected stage I, II or III NSCLC, provided such patients will be scheduled for a procedure that will provide histologic confirmation of the diagnosis (if the procedure does not provide histologic confirmation of the diagnosis of NSCLC the particular patient will be removed from the study and replaced). * Scheduled for treatment with surgery or radiotherapy (Stage I), surgery and chemotherapy (Stage II), or chemoradiotherapy (Stage III). For stage I receiving radiotherapy, treatment must be stereotactic body radiation therapy (SBRT) consisting of 3-5 fractions. * Ability to provide blood sample at the following time points: pre-treatment, 1 month post definitive treatment, and 4 post definitive treatment. * Ability to understand and the willingness to sign an IRB-approved informed consent document. * Staging studies including PET-CT for all patients prior to the initiation of primary treatment, as a pretreatment requirement. For patients with Stage II and III, MRI or CT of the brain is needed prior to the initiation of primary treatment. Patients, however, may be registered and have the pretreatment blood sample collected, provided that the staging studies are being scheduled. Registered patients who are found, after screening tests, to have Stage IV disease will be removed from the study and replaced. Exclusion Criteria: * Females who are pregnant * History of organ transplant. * For stage II and III patients, must be able to receive chemotherapy. * Active cardiovascular issues in the past 6 months.