Five-year results of a non-randomised study evaluating spiral computed tomography (sCT) for early detection of lung cancer (LC)

Abstract

7210 Background: In high-risk subjects low-dose sCT showed a 4-fold increase in the detection rate of neoplastic nodules in comparison with chest-X-ray. However, among studies there is a considerable discrepancy in the % of lung nodules, overall lung cancer and stage I detection rate as well as of the additional diagnostic work up. Subjects & Methods: From April to December 2001, 520 asymptomatic volunteers aged ≥ 55 years with a history of cigarette smoking ≥ 20 packs-year and of no previous cancer received annually chest sCT for 5 consecutive years. Results: At baseline 73% were male, median age was 59 years and 91% current smokers. At baseline sCT 127 subjects (24.5%) had nodules <5 mm while nodules ≥5 mm were detected in 114 (22%); the size of lung nodules ranged from 5 to 9.9 mm in 81.5% of the cases. The % of nodules worth of additional investigation varied over time (2 yr: 6%; 3 yr: 5%; 4 yr: 11%). Five (1%) cases of LC were detected during the 1st year (3 stage I) and in two additional resections an atypical adenomatous hyperplasia was found. Three new cases of thoracic cancers were detected in the 2nd, 3rd and 4th year of the study. Drop-out rate in the first year was 5% (2 yr 4,5%, 3 yr 2.3% and 4 yr 3%). One interval case was detected during the 3rd year. Subjects who quitted smoking in the 1st year were 13% and the % decreased over years (6% at the end of 3rd yr and 3% at 4th and 5th yr) and among quitters failure rate was 1–2%/year. In 3% of cases quitting was related to an acute cardiovascular or respiratory event. Fifty % of subjects showed some radiological signs of emphysema. Conclusions: Evidence from ongoing randomised trials is needed to support the routine use of sCT for early detection of LC. A program of smoking cessation is strongly recommended for further studies. Currently a conservative attitude should be encouraged. No significant financial relationships to disclose.