Utilization of computed tomography scans and lung cancer development in patients with pulmonary symptoms: A national database study.

e13594 Background: Lung cancer screening with chest computed tomography (CT) is recommended for asymptomatic 50–80-year-olds who have a significant smoking history. Pulmonary symptoms in such patients may further increase the risk of a lung cancer diagnosis. We sought to determine rates of CT utilization and lung cancer diagnosis in otherwise screen-eligible patients who present for an ambulatory medical encounter with pulmonary symptoms. Methods: We identified patients in the Epic COSMOS national database, age 50-80, who had an ambulatory office visit in 2023 for > 1 of 9 defined ICD-10 codes of pulmonary symptoms associated with lung cancer (cough, shortness of breath, chest pain on breathing). We excluded patients with prior cancer, those with hemoptysis, and those who had a chest CT within the preceding year. To evaluate the relationship of symptoms with lung cancer, we also analyzed screen-eligible patients (based on age and a > 20 pack year smoking history) with an anchor encounter in 2023 who did not have pulmonary symptoms. Results: We identified 1,047,894 analyzable patients with pulmonary symptoms, 37,339 who were otherwise screen eligible. In addition, we identified 360,531 screen-eligible patients without symptoms. In those with pulmonary symptoms, a chest CT was performed in 5.1% of patients within 2 months of the ambulatory visit. On multivariable analysis, factors associated with chest CT utilization included smoking, age, race, gender, ethnicity, and the presence of multiple pulmonary symptoms ( p <0.0001 for all comparisons). The highest rate of CT utilization, 12.2%, was in otherwise screen-eligible patients with pulmonary symptoms. The 2-year cumulative incident rate of lung cancer for those with pulmonary symptoms was 0.8%, with higher rates noted in people who smoke (current/former smoker: 2.0% (n=163,439) vs. never-smoker: 0.3% (n=231,296), p <0.0001). Comparison of 2-year lung cancer rates within patients with > 20 pack year histories with or without symptoms revealed a much higher rate in those who had pulmonary symptoms (4.6% (n=37,339) vs. 3.1% (n=360,531), p <0.0001, on Cox proportional Hazards Ratio (HR) 1.79, 95% CI: 1.69 – 1.90). Patients with > 20 pack year histories with symptoms had lower rates of surgery and stereotactic body radiation and higher rates of systemic therapy for their cancer compared to patients with > 20 pack year histories without symptoms, suggesting they had more advanced stage disease. Conclusions: Chest CT imaging is uncommon in patients 50–80 years old presenting with pulmonary symptoms, even in those who would otherwise meet eligibility criteria for lung cancer screening. Patients aged 50-80 with > 20 pack year smoking history who have pulmonary symptoms have a relatively high 2-year incidence of lung cancer.