Abstract
Objective: We studied the clinical features of patients of with lung cancer discovered in chest CT examinations in Ningen Dock and evaluated this type of examination.
Methods: In 35,603 persons (28,952 males, 6,651 females) who underwent lung cancer screening by chest CT examination at our Ningen Dock facility between May 2006 and December 2010, the clinical features of subjects with primary lung cancer were studied and a comparative analysis of clinical background factors was conducted between male repeat examinees and first-time examinees.
Results: Malignant lung diseases were discovered in 35 males (30 cases of primary lung cancer, 3 cases of metastatic lung cancer, 2 cases of malignant lymphoma) and 8 females (7 cases of primary lung cancer, 1 case of metastatic lung cancer). Regarding primary lung cancer, in males 83% of this was the tissue type and in females 86% was adenocarcinoma, with rates for clinical stage I of 70% for males and 86% for females. However, cases of progression to stage III and IV were also noted in males. In a comparison of males in the repeat examinee group with those in the first-time examinee group, no significant differences were observed for such background factors as body mass index (BMI), lipid/glucose metabolism disorders, liver/kidney function, blood cell or smoking habit parameters, alcohol consumption or exercise time. A retrospective study of repeat examinees revealed that there had been particular findings in previous CT scans for all lung cancer cases.
Conclusion: Male smokers in their 40s with particular findings in the first CT scan should undergo repeat scans once a year and male non-smokers in this category every 2 - 3 years. It is also important for women of 50 or over to undergo a CT examination.
