BACKGROUND ILD is an established risk factor for LC, however, few data is available about the molecular profile of LC associated to ILD.

AIM To compare the histological and molecular signature of LC in a cohort of prospectively diagnosed patients with and without ILD.

METHODS 21 patients with ILD-LC were enrolled in our center between 2019 and 2022 and compared to 115 LC patients without ILD. Demographics, clinical, hematological and functional data was gathered at LC diagnosis. PDL-1 expression and driver mutations were analyzed as appropriate.

RESULTS ILD-LC and LC patients were similar in terms of age(67vs73years;p=0.09), smoking history(30vs25pack/years;p=0.24), BMI(25vs24Kg/m²;p=0.53) or comorbidities, but ILD-LC were mainly male(81vs53%;p=0.02). ILD-LC patients showed a significantly lower FVC% and DLco(78vs98% and 46vs65%;p<0.01). In ILD-LC group, eosinophils levels were significantly higher than in LC group(170vs110cell/mm3;p=0.01), whereas monocyte levels only trended toward significance(750vs660cell/mm3;p=0.056). In the ILD-LC population, the frequency of adenocarcinoma and squamous cell carcinoma were similar(38%and33%), while in the LC group adenocarcinoma was predominant(68%). ILD-LC patients tended to be diagnosed at earlier stages(43vs23.5%stageI-II;p=0.07), but did not differ regarding PDL-1 positivity(50vs45%;p=0.12) or driver mutations(33vs53%;p=0.31).

CONCLUSIONS ILD-LC patients showed similar prevalence of adenocarcinoma and squamocellular histotype, while adenocarcinoma was prominent in LC patients. LC tended to be diagnosed in earlier stages in ILD patients. We found no difference in carriage of driver mutations or PDL-1 positivity.