Clinical characteristics and prognostic impact of acute exacerbations in patients with interstitial lung disease and lung cancer: A single‐center, retrospective cohort study

BACKGROUND: Although acute exacerbation (AE) after treatment for lung cancer (LC) is a poor prognostic factor in patients with interstitial lung disease associated with lung cancer (ILD‐LC), the risk of AE according to cancer treatment type remains unclear. Therefore, in the present study, we aimed to investigate the association between AE and treatment received for LC in patients with ILD‐LC. METHODS: We conducted a retrospective study of patients with ILD‐LC who had undergone treatment for LC between January 2018 and December 2022. The primary study outcome was the incidence of AE within 12 months of treatment for LC according to treatment type. The association between AE and all‐cause mortality was evaluated as a secondary outcome. RESULTS: Among a total of 137 patients, 23 (16.8%) developed AE within 12 months of treatment for LC. The incidence of AE according to treatment type was 4.3% for surgery, 16.2% for radiotherapy, 15.6% for chemotherapy, and 54.5% for concurrent chemoradiation therapy (CCRT). Patients who received CCRT were more likely to develop AE, even after adjustment for covariables (hazard ratio [HR], 15.39; 95% confidence interval [CI]: 4.00–59.19; p < 0.001). In addition, AE within 12 months of treatment for LC was associated with an increased risk of all‐cause mortality (HR, 2.82; 95% CI: 1.13–7.04; p = 0.026). CONCLUSION: Among treatment options for patients with ILD‐LC, CCRT was associated with an increased risk for AE. In addition, patients with AE had a higher mortality rate than patients without AE.