Does low-dose computed tomography screening improve lung cancer-related outcomes?—a systematic review

Abstract

: Screening with low-dose computed tomography (LDCT) can potentially decrease the mortality rate of lung cancer by detecting tumors at earlier stages. Although a number of guidelines exist on the implementation of screening and the management of screening-detected lesions, the field has progressed since those were written in terms of the clinical data now available and the greater range of surgical options now on offer to patients. This systematic review aims to provide an updated assessment of how LDCT screening may impact lung cancer-related outcomes in light of such recent data and surgical progress. A systematic literature search was conducted to identify articles focused on the use of LDCT to screen for primary non-small cell lung cancer in asymptomatic individuals. Of 2,880 articles identified, high quality papers reporting the results of 27 major studies were selected for in-depth analysis—including 17 observational studies (15 prospective and 2 retrospective), and 11 randomised-controlled trials. LDCT screening detected lung cancer in 0–8.2% of asymptomatic adults subject. These rates were demonstrated in most studies to be significantly higher than the lung cancer detection rate with no screening. Invasive procedures for benign lesions were performed in 0.07–1.9% of LDCT-screened subjects. Most LDCT screening-detected lung cancers presented in stage I, and 52–100% of patients with LDCT-detected lung cancer received surgery. Two large randomized-controlled trials showed that LDCT screening was associated with a 20.0% reduction in mortality when compared to chest X-ray (CXR) screening, and a 26% reduction in mortality when compared to no screening. LDCT screening is associated with: higher rates of lung cancer detection; diagnosis of lung cancer at an earlier stage; greater likelihood of surgical therapy being given; and lower mortality from lung cancer. The rate of ‘unnecessary’ interventions as a result of LDCT screening is low.