Article Text
Abstract
Background The effects of low-dose CT screening on disease stage shift, mortality and overdiagnosis are unclear. Lung cancer findings and mortality rates are reported at the end of screening in the Danish Lung Cancer Screening Trial.
Methods 4104 men and women, healthy heavy smokers/former smokers were randomised to five annual low-dose CT screenings or no screening. Two experienced chest radiologists read all CT scans and registered the location, size and morphology of nodules. Nodules between 5 and 15 mm without benign characteristics were rescanned after 3 months. Growing nodules (>25% volume increase and/or volume doubling time<400 days) and nodules >15 mm were referred for diagnostic workup. In the control group, lung cancers were diagnosed and treated outside the study by the usual clinical practice.
Results Participation rates were high in both groups (screening: 95.5%; control: 93.0%; p<0.001). Lung cancer detection rate was 0.83% at baseline and mean annual detection rate was 0.67% at incidence rounds (p=0.535). More lung cancers were diagnosed in the screening group (69 vs 24, p<0.001), and more were low stage (48 vs 21 stage I–IIB non-small cell lung cancer (NSCLC) and limited stage small cell lung cancer (SCLC), p=0.002), whereas frequencies of high-stage lung cancer were the same (21 vs 16 stage IIIA–IV NSCLC and extensive stage SCLC, p=0.509). At the end of screening, 61 patients died in the screening group and 42 in the control group (p=0.059). 15 and 11 died of lung cancer, respectively (p=0.428).
Conclusion CT screening for lung cancer brings forward early disease, and at this point no stage shift or reduction in mortality was observed. More lung cancers were diagnosed in the screening group, indicating some degree of overdiagnosis and need for longer follow-up.
- Lung neoplasms
- mass screening
- randomised controlled trial
- mortality
- overdiagnosis
- bronchoscopy
- clinical epidemiology
- imaging/CT MRI
- lung cancer
- non-small cell lung cancer
- small cell lung cancer
- alpha1 antitrypsin deficiency
- inhaler devices
- pulmonary embolism
- clinical epidemiology
- lung cancer
- tobacco and the lung
- lung proteases
Statistics from Altmetric.com
- Lung neoplasms
- mass screening
- randomised controlled trial
- mortality
- overdiagnosis
- bronchoscopy
- clinical epidemiology
- imaging/CT MRI
- lung cancer
- non-small cell lung cancer
- small cell lung cancer
- alpha1 antitrypsin deficiency
- inhaler devices
- pulmonary embolism
- clinical epidemiology
- lung cancer
- tobacco and the lung
- lung proteases
Footnotes
See Editorial, p 283
Funding This study was supported by the Danish Ministry of Interior and Health.
Competing interests None.
Ethics approval Ethics approval was provided by Committee of Copenhagen County and the Danish Data Protection Agency.
Provenance and peer review Not commissioned; externally peer reviewed.