Targeted screening for lung cancer with autoantibodies.

Earlier detection of lung cancer is possible, but difficult and costly to achieve. Screening with Low Dose Computed Tomography (LDCT)scanning has been shown to reduce mortality by 20-25% over the past decade but uptake amongst those most likely to suffer the disease has been slow. Resource constraints and a high false positive rate have also limited adoption of LDCT in many health systems. Targeted screening of people most likely to benefit using a range of biomarkers may be one way to improve the yield and reduce the resource requirements of LDCT. Autoantibodies, which amplify the signal produced by cancer derived proteins, are present in the blood of people mounting an immune response to cancer are a potential way to select those at highest risk. We have followed up 12 208 people enrolled in the ECLS trial for three years and shown that the specificity for early stage (I &II) disease is 90.3% throughout that period. More cancers were detected in the control than the intervention arm of the trial (101V 83). Sensitivity was 77.8% after 6 months and dropped to 46.4% after 3 years. At the end of three years the hazard ratios (95%CI) for All Cause, Cancer Specific and Lung Cancer Mortality was 0.82(0.67-1.01), 0.72(0.54-0.97) and 0.70(0.46-1.08) respectively for those randomised to Early CDT testing. As a range of treatment modalities become increasingly more effective it is even more important to target LDCT on those most likely to have early stage disease. Autoantibody testing may be one method of targeting early detection on those most likely to benefit.