A 16-year retrospective evaluation of opportunistic lung cancer screening with Low-Dose CT in China: comparative findings between never smokers and smokers

Abstract Background Although low-dose computed tomography (LDCT) screening effectively reduces LC mortality in high-risk individuals with a history of smoking in China, the feasibility and efficacy of lung cancer screening (LCS) in never-smokers versus smokers remains unclear. Methods We conducted a retrospectively opportunistic analysis at the National Cancer Center (NCC) in China from January 2006 to December 2022. A comprehensive LCS initiative was undertaken, involving 30,468 participants (54.5% male). Participants underwent LCS using LDCT. Potential malignancies were managed through joint consensus between patients and their physicians. Epidemiology, screening eligibility criteria, and LC detection rates and survival outcomes were compared between smokers and never-smokers. Results Among 30,468 participants, 339 LCs were pathologically confirmed in 289 patients. The LC detection rate was 0.9% overall, 0.8% in smokers (71/9,042), and 1.0% in never-smokers (218/21,426). In smokers, LC detection rates were 0.5% and 1.1% in the P = 0.001). Early-stage LC (stage 0 or I) was detected in 73.8% of smokers and 78.8% of never-smokers, while advanced LC (stage III–IV) was found in 8.8% and 4.2%, respectively. Significant differences in histologic types were found between smokers and never-smokers (P = 0.01), although adenocarcinoma was the most prevalent in both groups, at 83.0% and 78.8%, respectively. The median nodule size was 9.9 mm (8.0–13.8) in smokers and 9.2 mm (6.8–13.6) in never-smokers (P = 0.228). Never-smokers tended to favour surgical treatment alone (88.0%) more than smokers (81.3%). The 10-year survival rate was higher in never-smokers (92.6%) than in smokers (88.8%). Only 15.6% of patients with LC met the United States Preventive Services Task Force (USPSTF) criteria for LDCT eligibility, while 29.1% met the China guideline for the screening and early detection of lung cancer (CGSL) criteria. Conclusions LDCT screening improves early LC detection and treatment outcomes for both smokers and never-smokers. Significant differences exist in epidemiology, histologic type, and survival between these groups. USPSTF and CGSL criteria overlook a significant number of LC cases, underscoring the need to relax smoking criteria and include never-smokers into the Chinese LCS programme.