Lung cancer is the leading cause of death from cancer and the most effective way to reduce lung cancer mortality is early detection and treatment. The low-dose computed tomography (CT) can reduce the chances of lung cancer death, and used as screening test in several countries. Pulmonary nodules are a common finding in smokers, and differential diagnosis from cancer is a particularly important in lung cancer screening in smokers. We tried to find out the characteristics of lung nodules in patients who underwent smoker cancer screening. Data on low-dose lung CT findings and smoking counseling were collected for lung cancer screening patients for smokers conducted from January 2012 to June 2022. Out of a total of 1,320 patients, 1,101 had lung nodules. Lung nodules located in the right upper lobe were the most common at 30.5%, and lung nodules located in the right middle lobe were the least at 11.5%. Solid nodules were 97.3%, and ground-lass shadowing lesion was 2.4%. The average nodule size was 3.33 mm, and the largest was 43 mm. Compared to the previous test, 8.8% of the nodules were changed, and 1.8% of the total were suspected of cancer. The number of cessation patients interviewed was 138 (10.5%), and 98 were referred to smoking cessation clinics. This study shows that the lung nodule reporting rate is higher than overseas lung nodule reporting rate.

This study aimed to analyze the correlation between smoking and coronavirus disease 2019 (COVID-19) severity by region and gross domestic product (GDP). The regions were categorized by continent and GDP rankings. Studies conducted between June 3, 2020 and March 27, 2023 were searched to compare the severity of COVID-19 between smokers and non-smokers according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Compared with never-smokers, the smokers’ COVID-19 severity scores were 1.48 (confidence interval [CI]: 1.25–1.75) in Asia, 1.24 (CI: 1.05–1.46) in the Middle East, 1.32 (1.21–1.45) in Europe, 1.39 (1.30–1.49) in North America, 1.69 (1.22–2.34) in South America, and 2.87 (1.82–4.53) in Africa. By GDP, the smokers’ COVID-19 severity scores were higher than those of never-smokers: 1.42 (1.32–1.53) in high-GDP countries, 1.33 (1.25–1.41) in middle-GDP countries (11th–50th), and 1.53 (0.85–2.76) in low-GDP countries. The COVID-19 severity in smokers was significantly higher in low-GDP countries than in high- and middle-income countries. The high COVID-19 death rate among smokers in the African continent and low-GDP countries is thought to stem from the lack of medical management systems compared with other countries. In addition to medical treatment, environmental or socioeconomic factors can increase the severity.