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Vol.59 No.4 contents | Japanese/English |
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- Original Article -
Involvement of Eosinophils in the Antitumor Effect of Immune Checkpoint Inhibitors
Sakae Fujimoto1, Koichi Minato1, Misa Iijima2, Yoshimasa Nakazato31Department of Pulmonary Medicine, 2Department of Clinical Pathology, Gunma Prefectural Cancer Center, Japan, 3Pathology Diagnostic Course, Dokkyo Medical University, Japan
Objective. When we reported a case in which a complete response was observed in a patient treated with nivolumab, we hypothesized that eosinophils are involved in the tumor immune response to nivolumab. In the present study, we retrospectively analyzed the relationship between tumor tissue-infiltrating eosinophils before the administration of an immune checkpoint inhibitor (ICI) and the effect of ICIs. Methods. We reviewed the cases of 53 patients with a history of ICI treatment at our hospital between February 2016 and June 2018. We divided the cases into a tumor-associated tissue eosinophilia (TATE)-negative group (n=32) and a TATE-positive group (n=21) based on a tumor tissue-infiltrating eosinophil count of 7 per 10 high-power fields. Results. The median progression-free survival (PFS) in the TATE-positive group was significantly longer than that in the TATE-negative group (12.0 months [95%CI 3.8-20.2] vs. 3.0 months [95%CI 0.9-5.1]; p=0.035). A significant correlation was observed between the blood eosinophil count and the tumor tissue-infiltrating eosinophil count (p=0.001; correlation coefficient 0.429). The changes in the blood eosinophil count between the first and second ICI administrations did not differ between the two groups (p=0.381). Conclusion. Tumor tissue-infiltrating eosinophils before the administration of ICI were related to an increase in the blood eosinophil count, which may improve the effect of ICIs.
key words: Immune checkpoint inhibitor, Eosinophil, Lung cancer, Predictive factor, Prognostic factor
Received: January 29, 2019
Accepted: May 27, 2019
JJLC 59 (4): 342-347, 2019
