CT screening for “early” lung cancer is a topic under current investigation in an increasing number of centers worldwide. However, a number of centers have already reported the results of chest CT scanning in the assessment of candidates for surgical management of pulmonary emphysema. To our knowledge, six series have reported rates of discovery of stage I lung carcinoma at CT evaluation of these subjects (Table 1
). Combining the data of these studies, CT-detected stage I and stages II through IV carcinoma of the lung showed overall prevalences of 3.0% and 0.7%, respectively. These prevalences differ significantly (χ2 = 16.0, p < 0.01); the proportions of stage I vs stages II-IV cancers in the six series are homogeneous (χ2 = 4.67, p = 0.46, not significant [NS], and χ2 = 4.45, p = 0.49, NS, respectively), ie, the differences among the series can be regarded as chance fluctuations. %These results, obtained from populations who were fit to undergo thoracic surgery and in the age range for which lung cancer is common, support the concept that CT screening for early stages of lung cancer may prove efficacious.