Lung cancer screening with low-dose spiral computed tomography

Computed tomography (CT) has been compared to plain radiographs and bronchial washings as a screening tool for lung cancer. In comparison with other screening modalities, CT allows detection of lung lesions at an earlier cancer stage. Technologic improvements have decreased imaging costs, thus making chest CT a more feasible option as a screening tool in the community hospital. In this study, smokers over the age of 45 years with a greater than 20 pack-year smoking history were referred for screening chest CT. Noncalcified nodules larger than 10 mm underwent CT-guided biopsy, and smaller nodules underwent follow-up CT in 3 months. Currently, patients have been followed for 4 years. The prevalence, stage, and histology of lung cancer were compared to study results from academic centers. Eighty-seven patients underwent screening chest CT. The study population was 51 per cent male with a mean age of 64 +/- 9 years. Four (3 female and 1 male) patients were biopsied and found to have lung cancer giving a prevalence of 5 per cent. Stage IA disease was found in three patients and stage IIIA disease was found in one patient. Adenocarcinoma was present in two patients, adeno-squamous carcinoma in one patient, and squamous cell carcinoma in one patient. The stage and histology of lung carcinomas in this study were comparable to studies performed at larger institutions. However, the disease prevalence was almost double the highest prevalence found in other studies. This discrepancy could be related to study size, as the patient populations were similar. Clearly, screening chest CT in the community setting is equally efficacious in the diagnosis of lung cancer at earlier stages. Following these patients beyond the 5-year mark will give some insight on the effect of screening chest CT on the mortality of lung cancer.