Screening for lung cancer using low dose CT scanning: results of 2 year follow up

Background: Screening with low dose chest computed tomographic scanning (LDCCT) may improve survival by identifying early asymptomatic lung cancer. Methods: Four hundred and forty nine high risk subjects were screened with serial LDCCT scanning over 2 years. Fine needle aspiration biopsy was recommended for non-calcified nodules (NCNs) of >10 mm diameter or demonstrating interval growth. Results: NCNs were identified in 111 subjects (24.7%), three of which were lung cancer. The overall prevalence (0.4%) and incidence (1.3%) rates of lung cancer detection were low. Three of the six lung cancers detected in the study were stage 1 non-small cell lung cancer; the remainder were unresectable central tumours. By contrast, eight subjects developed extrathoracic malignancy during the study period and other incidental pathology was noted in 221 subjects (49.2%). Smoking cessation rates at 19% were higher than in the general population, but 60.8% of subjects continued to smoke. Conclusion: LDCCT scanning is useful in detecting early peripheral non-small cell lung cancers but its usefulness as a screening tool is limited by low specificity and by poor sensitivity for central tumours.