Effectiveness of Lung-RADS in Reducing False-Positive Results in a Diverse, Underserved, Urban Lung Cancer Screening Cohort.

PURPOSE: The Lung CT Screening Reporting and Data SystemTM (Lung-RADSTM ) was created to standardize lung cancer screening CT reporting and recommendations but has not been well validated prospectively in clinical practice. The aim of this study was to determine the effectiveness of lung cancer screening using Lung-RADS in a diverse, underserved, academic clinical screening program, focusing on whether Lung-RADS would successfully reduce the 23.3% false-positive rate found in the National Lung Screening Trial.

METHODS: Institutional review board approval was obtained to study the clinical lung cancer screening cohort. Low-dose CT results were prospectively assigned a Lung-RADS or equivalent score. The proportion of examinations in each Lung-RADS category and the corresponding lung cancer rate, subsequent imaging, interventions, mortality, and compliance were tracked. The National Death Index was queried for follow-up losses.

RESULTS: The cohort comprised 1,181 patients with 2,270 person-years of follow-up from December 2012 to December 2016. The mean age was 64 ± 16.2 years, with 51% women, 63% nonwhite, 71% current smokers, 69% overweight and obese, and multiple comorbidities. The Lung-RADS false-positive rate was 10.4% (95% confidence interval, 8.8%-12.3%). Baseline CT results were negative in 87% (n = 1,031): for Lung-RADS 1, the lung cancer rate was 0.2%, and for Lung-RADS 2, the cancer rate was 0.5%. Positive baseline examinations were Lung-RADS 3 in 10% (n = 119), 4a in 1.2% (n = 14), and 4b in 1.5% (n = 18). Corresponding cancer rates were 3.4%, 43%, and 83%, respectively. Lung cancer prevalence was 2.1%. Mortality was 40% in patients with lung cancer versus 2.5% in the remaining cohort (P < .001). Fifty-four percent of patients were overdue for first annual examinations. Eighty-four percent of patients (n = 989) had follow-up verified via electronic records or personal contact, and the remainder had vital status ascertained via the National Death Index.

CONCLUSIONS: Lung cancer screening using Lung-RADS was effective in reducing the false-positive rate compared with the National Lung Screening Trial in a diverse and underserved urban population.