Performance of low-dose computed tomography on lung cancer screening in high-risk populations: The experience over five screening rounds in Sichuan, China.

Objective: To evaluate the performance of low-dose computed tomography (LDCT) on lung cancer screening in high-risk populations in Sichuan.

Methods: From April 2014 to July 2018, LDCT was performed annually on 3185 subjects aged 50-74 years who had smoked ≥ 20 pack-years (or subjects having quit smoking within 5 years). Information about all deaths and lung cancer diagnoses were obtained by active investigation, or passive matching to disease surveillance system.

Results: The screening population had a median age of 60 years. 62.4 % of which were current smokers and had smoked 30 pack-years. After participating in the baseline screening, the compliance rates of subjects consecutively completing one round, two rounds, three rounds, and four rounds of annual screening were 67.22 %, 52.84 %, 43.24 %, and 40.04 %, respectively. The positive rates in baseline and annual screening were 6.53 % and 5.79 %, respectively. During the 5 rounds, a total of 9522 person-times were screened by LDCT with a screening sensitivity of 89.13 % (95 % CI: 76.96-95.27), specificity of 94.36 % (95 % CI: 93.88-94.81), positive predictive value of 7.13 % (95 % CI: 5.30-9.53), and negative predictive value of 99.94 % (95 % CI: 99.87-99.98). There were no statistically significant performance differences between baseline and annual screening. The difference in the proportion of screen-detected stage I lung cancer between baseline screening and annual screening was not statistically significant, neither.

Conclusion: The application of LDCT on lung cancer screening in high-risk populations shows favorable compliance and a high screening performance in the project area of Sichuan,China.