Pre-existing interstitial lung abnormalities are risk factors for immune checkpoint inhibitor-induced interstitial lung disease in non-NSCLC cancers

e15171 Background: Immune check point inhibitor (ICI) induced interstitial lung disease (ICI-ILD) is a clinically serious and life-threatening toxicity. Pre-existing ILD has been reported to be a risk factor for ICI-ILD in patients with non-small cell lung cancer (NSCLC). In addition, we have previously reported that interstitial lung abnormality (ILA) is also a risk factor for the ICI-ILD. Therefore, we investigated whether any patient characteristics, including ILA, were risk factors for ICI-ILD in patients with non-NSCLC cancers. Methods: Head and neck cancer, malignant melanoma, oral cavity cancer, renal cell carcinoma or gastric cancer patients who received anti PD-1 antibody (Nivolumab or Pembrolizumab) at Hiroshima University Hospital from December 2015 to May 2019 were enrolled. Information on patient characteristics before anti-PD-1 antibody administration, including chest CT findings and laboratory data, were obtained. Results: Two hundred patients were enrolled, and 20 (10%) developed ICI-ILD. Grade1 was observed in 15 patients, grade2 in 3, and grade3 and 5 in 1. There was no significant difference in the background factors between patients with and without ICI-ILD. On the other hand, the proportion of patients with ILA was significantly higher in the patients with ICI-ILD than those without (P < 0.01). Furthermore, univariate logistic regression analysis revealed ILA was the risk factor for ICI-ILD (p < 0.01), and multivariate logistic regression analysis showed that GGA or reticulation in ILA was an independent risk factor for ICI-ILD (p = 0.016, 0.011). Conclusions: Pre-existing ILA is a risk factor for ICI-ILD, and GGA or reticulation in ILA is an independent risk factor for ICI-ILD in patients with non-NSCLC cancers. Therefore, we should pay more attention to the development of ICI-ILD in patients with ILA, especially GGA or reticulation.