PURPOSE: Chemoimmunotherapy is the primary treatment approach for non-small cell lung cancer (NSCLC)
however, it is associated with immune-related adverse events (irAEs). Corticosteroids can control irAEs through their anti-inflammatory and immunosuppressive effects. Dexamethasone (DEX) is a potent corticosteroid commonly used to prevent chemotherapy-induced nausea and vomiting (CINV). This study aimed to the association of corticosteroids used to alleviate CINV and irAE occurrence. METHODS: This retrospective study included patients with NSCLC who underwent chemoimmunotherapy across eight hospitals. Cases lacking aprepitant use were excluded. All corticosteroids for CINV were standardized to intravenous DEX doses, and cutoff values were calculated using receiver operating characteristic curve analysis. Logistic regression analysis was performed to investigate irAE risk factors. RESULTS: The cutoff value for DEX was 15.9 mg (area under the curve, 0.58
95% confidence interval, 0.45-0.70
sensitivity, 0.63
specificity, 0.61), with 99 and 76 patients in the DEX <
15.9 and ≥ 15.9 mg groups, respectively. Patients in the DEX <
15.9 mg group had a significantly higher incidence of irAE than patients in the DEX ≥ 15.9 mg group (P = 0.03). Multivariate analysis identified that DEX <
15.9 mg was a risk factor for irAEs (P = 0.04
odds ratio: 2.51
95% confidence interval, 1.03-6.09). CONCLUSION: Corticosteroids with DEX equivalent doses of <
15.9 mg in combination with aprepitant for CINV may elevate the risk of irAEs. Therefore, diligent monitoring for irAEs occurrence is warranted in regimens utilizing DEX-equivalent corticosteroid doses of <
15.9 mg combined with aprepitant for CINV prevention.