Antifibrotic therapy and lung cancer risk in patients with idiopathic pulmonary fibrosis: a large retrospective propensity-weighted cohort study

BACKGROUND: Antifibrotic (AF) therapy has been shown to potentially reduce the risk of lung cancer (LC) in patients with idiopathic pulmonary fibrosis (IPF). Our study further assesses the impact of AF use and LC incidence in a real-world cohort with patient-level data. METHODS: A retrospective multisite cohort study involving patients with IPF followed at Mayo Clinic between 2005 and 2022 was conducted. We identified individuals with new diagnoses of LC in the pre-AF and post-AF eras and defined AF use as continuous treatment for 6 months or more before LC diagnosis. Given the inclusion of LC cases prior to the wide availability of AF therapy and potential differences in patients exposed and unexposed to treatment, propensity score analysis with inverse probability of treatment weighting (IPTW) was used to balance comparator groups. Fine and Gray modelling was used to explore risk factors for developing LC, reported as parameter subdistribution HRs (SHR). RESULTS: A total of 3313 patients with IPF were included (1161 treated and 2152 non-treated). LC incidence rates were lower for treated patients in the post-AF era (0.34 vs 1.25 per 100 person-years, p