Low dose spiral computed tomography for early diagnosis of lung cancer. Results of baseline screening in 5,000 high-risk volunteers

Abstract

7029 Background: The high lethality of lung cancer is related to the advanced stage at diagnosis. Early studies have demonstrated that screening with CT is effective to diagnose lung cancer at earlier stage but the optimal clinical approach for the management of patients identified with nodules during screening has yet to be defined. We report the first-year results of our CT screening trial. Method: Between October 2004 and October 2005, 5,189 asymptomatic current or former smokers of more than 20 packs/year, older than 50 years, were enrolled in a single-institution screening trial using annual low-dose multidetector CT for 5 years. A protocol for the diagnostic work-up of nodules identified by CT was LD-CT at 1 year for nodules with maximum diameter less than 5 mm, LD-CT at 3 months for lesions between 5.1 and 8 mm and FDG-PET for lesions larger than 8.1 mm. Trans cutaneous biopsy was not routine part of this protocol. End-points were: prevalence and incidence rates of lung cancer, stage distribution, resectability, recall rate and invasive procedure for benign disease. Results: Median age of volunteers was 57 years, 66% were males and 80% current smokers. The prevalence of lung cancer diagnosed at first CT was 1.0% (54 cases; 65% stage I; 9% stage II; 22% stage III and 4% Stage IV). Forty-seven tumors (87%) were radically resected (45 lobectomies, 1 pneumonectomy, 1 atypical segmentectomy). Major surgical morbidity and mortality were 4% and 2% respectively. Recall rate was 10%. Seven patients (1.3% of all recalled subjects) underwent surgical diagnostic procedures for non-malignant disease representing 12% of all screening surgical procedures versus 16% in a non-screening control group treated in the same unit and period. Conclusions: Our results confirmed that screening with low-dose CT allows the detection of early stage lung cancer in a high proportion of cases increasing the probability of cure. Although follow-up is necessary to confirm the efficacy of the proposed work-up protocol, the initial results are promising, with a very low number of invasive procedures performed for benign lesions. No significant financial relationships to disclose.