Stage-size relationship in long-term repeated CT screening for lung cancer: Anti-Lung Cancer Association project

1540 Background: We have investigated the individualized benefit of CT screening as Anti-Lung Cancer Association projects (presented at ASCO 2006–2008). However, there has not been enough information about the relationship of lung cancer stage to tumor size in repeated CT screening. Therefore, we evaluated the stage-size relationship of these asymptomatic lung cancer cases diagnosed by long-term repeated screening with low-dose helical CT. Methods: Among 2,120 participants (mean age 63 years, 87% male, and 83% smoker) at baseline screening, 1,877 underwent semiannually repeated screening from 1993 to 2004. Nineteen (0.90%) prevalence cancers and 57 (0.32%) incidence cancers were detected. Within categories of tumor size, the distribution of pathological stage, histology, lymph node status, and distant metastases was determined. Results: Pathological stage has a strong relationship to tumor size at baseline screening (spearman r = 0.63, p = 0.013) and repeated screening (r = 0.65, p < 0.001). In the analys...