Lung cancer screening with low-dose computed tomography: Experiences from a tertiary hospital in Taiwan

Lung cancer screening using low-dose computed tomography (CT) has been reported to reduce lung cancer-specific mortality for smokers at high risk. However, despite different characteristics of lung cancer in Asia, there are few data concerning this specific population for screening. We aim to analyze the performance of lung cancer screening with low-dose CT concurrent with chest radiography in Taiwan, with reference to international experience.

During the 1-year period from January 2012 to December 2012, we conducted a retrospective, single-center population-based screening program for lung cancer in the setting of annual medical examinations. Participants were asymptomatic adults without prior history of any cancer. Low-dose CT and chest radiography were offered to all individuals. Baseline CT evaluations were defined as positive if any noncalcified nodule≥4 mm in diameter, which were then classified as solid, pure ground-glass or partial ground-glass opacity.

Of 3339 individuals, we detected 34 cancers, yielding an overall cancer detection rate of 1.02%. There was a particularly high cancer detection rate of 6.2% (8/129) in the high-risk group aged younger than 50 years with a positive family history of all types of cancers in first-degree relatives. Adenocarcinomas accounted for 88% (30/34) of cancers and 99% of them were early-stage (including carcinoma in situ and Stage I). The probability of cancers was significant higher in nodules with interval growth (odds ratio 257.89, p = 0.0002). There was no significant difference in the probability of cancers between ground glass opacity nodules and solid nodules (odds ratio 1.16, p=0.72). Of all screen-detected cancers, 61.76% (21/34) were chest radiographically occult.

Low-dose CT is effective to detect early lung cancers. Further establishment of selection criteria for lung cancer screening, specifically for Asian individuals, is definitely warranted.