Low-dose computed tomography (LDCT) screening for lung cancer has been recommended for high-risk individuals meeting the National Lung Screening Trial (NLST) criteria. However, there still is a debate concerning respective recommendations for Asian countries. Meanwhile, the proper duration and interval for lung cancer screening remains uncertain.
From November 2013 to July 2016, participants from Xuhui district of Shanghai were aged 45-70 years, and with either of the following risk factors: 1) smoking history ≥20 pack-years, and, if a former smoker, had quit within the past 15 years; 2) cancer history in immediate family members; 3) personal cancer history; 4) professional exposure to carcinogens; 5) long term exposure to second-hand smoke; 6) long term exposure to cooking oil fumes. The eligible participants were randomly assigned to a screening arm with two rounds of alternate years LDCT screens and a control arm.
A total of 6659 eligible participants were enrolled, 3147 participants were randomly assigned to control arm, 3512 were assigned to LDCT prevalence screening (S1), of which 1516 participants underwent the second round of LDCT screening (S2) in the alternate year. Positive screening results were observed in 849(24.2%) participants in S1 and 380 (28.0%) in S2. 80 (2.3%) cases were highly suspected of lung cancer in S1 and 31 (2.0%) in S2 according to the suggestions from multiple disciplinary team. By April 2017, lung cancer was diagnosed in 44 participants (1.3%) after S1, 12 (0.8%) after S2, and 10 (0.3%) in the control group (stage 0 to I: 97.7%, 91.7% vs 20%; stage II to IV: 2.3%, 8.3% vs 80%). Only 18 (32%) of these 56 lung cancer patients detected by LDCT would have qualified as NLST high-risk patients. There were 2 lung cancer-specific deaths in control group, whereas 0 in the screening arm participants.
LDCT screening increased the detection of early-stage lung cancer and reduced lung cancer-specific mortality. In China, lung cancer CT screening may also benefit patients outside the NLST criteria with great efficiency. Screening done at biennial intervals could be taken into consideration due to few advanced-stage diseases.
Clinical trial identification
Legal entity responsible for the study
Shanghai Chest Hospital
Shanghai Municipal Commission of Health and Family Planning
All authors have declared no conflicts of interest.