Background

Lung cancer is the leading cause of cancer death worldwide. Cigarette smoke remains the leading risk factor. In the last years, the association between immune-mediated inflammatory diseases (IMIDs) and bowel and hematological malignancies has been increasingly studied, but data on lung cancer are still lacking.

Aims and objectives

To investigate the prevalence of IMIDs in patients with a new diagnosis of lung cancer. Methods This was a retrospective, cohort, real-life study, that enrolled patients who underwent a bronchoscopy in the Respiratory Disease Unit of Ospedale Luigi Sacco from January 2019 to December 2022. The specimen collected for the diagnosis included broncho-alveolar lavage (BAL), lymph-node transbronchial needle aspiration (TBNA) with or without endo-bronchial ultrasound (EBUS), bronchial brushing and endobronchial biopsies.

Results

A total of 1059 patients were included (360 from 2019, 166 from 2020, 252 from 2021 and 281 from 2022). Lung cancer was diagnosed in 156 patients (14.7%): 70 (44.9%) with adenocarcinoma, 27 (17.3%) with squamous cell carcinoma, 11 (7.1%) with non-small cell lung cancer, 27 (17.3%) with small cell lung carcinoma and 21 (13.5%) had pulmonary metastases from different primary tumors. Among these patients, the prevalence of IMIDs was 6.4%, including 1 (0.6%) with rheumatoid arthritis, 5 (3.2%) with connective tissue disorders, 1 (0.6%) with inflammatory bowel diseases, 1 (0.6%) with a cutaneous inflammatory condition, and 2 (1.3%) with interstitial lung diseases.

Conclusions

This study shows a possible association between IMIDs and lung cancer. Further studies are warranted to establish the potential increased risk of lung cancer in IMIDs.