Inclusion Criteria:  Patients invited to participate in the Royal Marsden (RM) Partners Lung Health Check pilot study who undergo one or more CT scans: Between the age of 55-75 years of age; and Current smokers or ex-smokers who have quit after the age of 40.  Exclusion Criteria:  Patients excluded from the Lung Health Check: On the palliative care register; Any active malignancy undergoing treatment Daily activity levels equivalent to performance score 3 or 4; and Unable to consent to Lung Health Check Biomarker Study