Introduction and aim: The Australian lung cancer screening program using low-dose CT chest is due to commence in 2025. The aim of this study was to compare the utility of categorical selection criteria (United States Preventative Services Task Force USPSTF2021) and a risk calculation model (PLCOm2012) in identifying high-risk patients for lung cancer screening.
Methods: We compared the screening eligibility of applicants in the NSW cohort of the International Lung Screening Trial (ILST) according to USPSTF2021 and PLCOm2012 (1.5%/6 years) criteria. We also compared the calculated lung cancer risk using the PLCOm2012 model and risk factor profiles of eligible applicants by each criteria. All variables were reported as mean+/-standard deviation and number (percentage). Statistical analysis was completed using the Mann-Whitney, McNemar and Chi-squared tests. A p-value<0.05 was deemed significant.
Results: The NSW ILST cohort had 926 applicants. All were assessed by PLCOm2012 (risk calculation) and USPSTF2021 (categorical) criteria. The PLCOm2012 criteria selected fewer candidates than USPSTF2021 (54% vs 59%, p=0.002) but selected those with higher calculated risk than USPSTF2021 (4.94±4.24%/6yrs vs 4.35±4.33%/6yrs, p<0.001). Compared with USPSTF2021, candidates eligible via PLCOm2012 were older (66±6yrs vs 64±6yrs, p<0.001), had higher smoking pack-years (49±22 vs 46±21, p=0.002) and more likely to have a family history of lung cancer (28% vs 21%, p=0.011). Sixty-nine applicants were eligible via PLCOm2012 criteria but excluded by the USPSTF2021 criteria. These applicants had similar calculated lung cancer risk (3.16±1.43%/6yrs vs 4.35±4.33%/6yrs, p=0.956), were older (71±5yrs vs 64±6 yrs, p<0.001), had similar number of smoking pack-years (48±28 vs 46±21, p=0.853) and were more likely to have a family history of lung cancer (51% vs 21%, p<0.001) compared to applicants selected by the USPSTF2021 criteria.
Conclusion: Selection of high-risk lung cancer screening candidates via USPSTF2021 categorical criteria may exclude candidates eligible via risk calculation with family history of lung cancer.