Performance of Low-dose CT Screening for Detecting Lung Cancer at the Early Stage and the Estimated Tumor Growth Rate According to the Smoking Status/Age

摘要

Objectives. To assess the utility of low-dose spiral chest CT (LDCT) screening for detecting lung cancer at the early stage and to examine the tumor volume doubling time (TVDT) according to the smoking status and age. Methods. A total of 295 patients who participated in an LDCT screening program for citizens of Nagano, Japan between 2000 and 2010 were examined with respect to the incidence, prognosis-related features (tumor size, proportion of clinical stage I tumors and histopathology) and TVDT of the lesions. Results. The prevalence rate of lung cancer was similarly high in all smoking categories (504 per 100,000 subjects for the entire group), especially high in the elderly subjects (>50 years) and low in the patients in their 40's. seen only in non-smokers. The annual incidence was 84 in all subjects, being particularly low in the non-smokers and zero in the 40-year-old group. The ratio of the prevalence cancer/annual repeat cancer was 6.0 (504/84), with 4.1 for smokers and 11.0 for non-smokers. The prognosis-related features were significantly different between the smokers and non-smokers, with smokers having alarger tumor size and lower proportion of c-stage Ilesions.