Results of a pilot risk-based lung cancer screening study: outcomes and comparisons to a Medicare eligible cohort

Risk-based lung cancer screening holds potential to detect more cancers and avert more cancer deaths than screening based on age and smoking history alone, but has not been widely assessed or implemented in the United States. The purpose of this study was to prospectively identify patients for lung cancer screening based on lung cancer risk using the PLCO_m2012 model and to compare characteristics, risk profiles, and screening outcomes to a traditionally eligible screening cohort.

Participants who had a 6 year lung cancer risk score ≥ 1.5% calculated by the PLCO_m2012 model and were ineligible for screening under 2015 Medicare guidelines were recruited from a lung cancer screening clinic. After informed consent, participants completed shared decision-making counseling and underwent a low-dose CT (LDCT). Characteristics and screening outcomes of the study population were compared to the traditionally eligible Medicare cohort with Fisher's Exact, t-tests, or Brown Mood tests, as appropriate.

From August 2016 to July 2019, the study completed 48 baseline LDCTs. 10% of LDCTs recommended further pulmonary nodule evaluation (Lung-RADs 3 or 4) with two early-stage lung cancers diagnosed in individuals that had quit smoking > 15 years prior. The study population was approximately 5 years older (p = 0.001) and had lower pack years (p = 0.002) than the Medicare cohort.

Prospective application of risk-based screening identifies screening candidates who are similar to a traditionally eligible Medicare cohort and future research should focus on the impact of risk calculators on lung cancer outcomes and optimal usability in clinical environments. This study was retrospectively registered on clinicaltrials.gov (NCT03683940) on 09/25/2018.