Large clinical trials have shown that lung cancer screening (LCS) with low dose computed tomography (LDCT) reduces lung cancer specific mortality by at least 20% in high-risk individuals [1, 2], and guidelines that drive insurance coverage are based on age and cigarette smoking history [3,4,5]. In 2015, the Centers for Medicare and Medicaid Services (CMS) recommended LCS in individuals 55–77 years old with a ≥ 30 pack year smoking history who currently smoke or have quit within the past 15 years [3]. Based on modeling data, the US Preventive Services Task Force (USPSTF) recommends screening through age 80 [4]. Recently, CMS and USPSTF expanded LCS guidelines by lowering age eligibility to 50 and tobacco exposure to 20 pack years [4, 5].

Risk-based screening defines screening eligibility based on individual risk factors and may detect more cancers and avert more cancer deaths [6,7,8]. There are several risk prediction calculators available, but the PLCOm2012 model [7] is one of the more accurate at identifying individuals with a history of cigarette smoking for screening and is based on eleven variables (age, race, education,, body mass index, presence of COPD/emphysema, personal history of cancer, family history of lung cancer, smoking status (current or former), cigarettes smoked per day, years smoked, years since quitting smoking) [8]. Early assessments of risk-based LCS have predominantly been based on modeling data or applied to screening cohorts retrospectively [8,9,10], and have more recently been tested prospectively in international studies [11, 12]. However, risk-based screening has not been widely assessed or implemented in the United States. The aim of this study was to prospectively identify and screen patients for lung cancer based on lung cancer risk using the PLCOm2012 model and to compare characteristics, risk profiles, LDCT outcomes, and lung cancer diagnoses to a LCS cohort that met standard screening eligibility. Some of the results of these studies have been previously reported in the form of an abstract, [13] this manuscript provides additional information on comparing characteristics and screening outcomes with the Medicare-eligible cohort.