Biomarkers for Risk Stratification in Lung Cancer

This is a prospective observational study that will follow patients who undergo lung cancer screening at the San Francisco VA Medical Center, University of California, San Francisco (UCSF) Medical Center, and the San Francisco General Hospital. The proposed study will comprise of two primary populations to determine the ctDNA assay performance in a variety of clinical settings.

Inclusion Criteria: * Age ≥ 40 years * Ability to understand and provide written informed consent * Willingness to comply with study protocols and provide blood samples. * Willingness to complete 3-year clinical follow up Exclusion Criteria: * Active non-cutaneous malignancy within the past 5 years as per medical record or patient report. * Exclusion criteria for possible follow-up visit blood draw: * Anemia - measured by hematocrit level of less than 30%, measured after the first blood draw. * Malnourishment - determined by BMI less than 19. If subject has BMI greater or equal to 19, but has a history of malnourishment, study staff will measure albumin level of subject's blood after initial blood draw. Albumin level must be greater than 2.5 mg per deciliter, or subject will be excluded. * Severe Chronic Obstructive Pulmonary Disease (COPD) - defined by Gold Stage IV. * Unstable heart conditions - defined by stable or unstable angina, recent myocardial infarction (within the last 2 years), active congestive heart failure, ischemic cardiomyopathy, or history of complications because of previous blood donation. * Liver cirrhosis.