Late Breaking Abstract - Antifibrotic Therapy and Risk of Lung Cancer in Patients with Idiopathic Pulmonary Fibrosis

<bold>Background:</bold> The incidence of lung cancer (LC) appears greater in patients with idiopathic pulmonary fibrosis (IPF) than in the general population. Antifibrotics including pirfenidone and nintedanib have been approved for the treatment of IPF. <bold>Aims and Objectives:</bold> Our study aims to assess the impact of antifibrotics on lung cancer risk in patients with IPF. <bold>Methods:</bold> The study design is a retrospective cohort involving patients with IPF from all Mayo Clinic sites between 2005 and 2022. All individuals diagnosed with LC after IPF diagnosis were reviewed, with the incidence of LC between those with and without antifibrotic therapy compared. As antifibrotic therapy was not available prior to 2014, propensity score analysis with inverse probability treatment weighting (IPTW) was used to account for potential differences in treatment exposure between the treated and non-treated groups. Fine and Gray modeling was used to calculate sub-hazard ratios (SHR) for LC risk using death prior to LC diagnosis as a competing event. <bold>Results:</bold> The incidence rate of lung cancer was significantly lower in those on antifibrotic therapy (0.34 vs 1.25, P<0.001, rate per 100 person-years). After IPTW propensity scoring, the weighted population included 2,148 individuals on antifibrotic therapy and 2,167 without. Antifibrotic was associated with reduced risk of LC after adjustment for age at IPF diagnosis, sex, smoking history, and baseline lung function (SHR of 0.36 (0.16-0.82), P=0.02). <bold>Conclusions:</bold> Incidence and risk of LC in patients with IPF appears to be reduced with antifibrotic therapy.