Lung Cancer Screening with Low-Dose CT: Baseline Screening Results in Shanghai

Objective: To report the initial baseline lung cancer screening results with low dose computed tomography (LDCT) in a multicenter study in Shanghai. Methods: A total of 14,506 subjects underwent LDCT lung cancer screening and completed questionnaires consisting of 13 risk factors for lung cancer in the prospective study. The positive result was defined as any size and density nodule. The nodules were classified into calcified, solid, part-solid, and nonsolid nodules. The positive rate and incidental detection rate of lung cancer and stage I lung cancer were calculated. The proportion of lung nodule and lung cancer with different density and size was analyzed. Results: The positive rate and incidental detection rate of lung cancer was 29.89% and 1.23%, respectively. The incidental detection rate of stage I lung cancer was 0.97%. The proportion of lung cancer in lung nodules and stage I in lung cancer was 3.48% and 81.09%, respectively. The ratio of nonsolid nodule, part-solid nodule, and solid nodule in lung cancer was 52.94%, 31.93%, and 15.13%, respectively. 74.88% lung nodules were less than 5 mm and 94.12% lung cancers were larger than 5mm in size. Conclusion: The baseline LDCT lung cancer screening showed subsolid nodules accounted for the majority of lung cancer, and 5 mm in size would be recommended as the positive result threshold.