Abstract 766: Expression of HER-2 statue and PD-L1 is associated with prognosis in gastric cancer

Abstract

Abstract Background PD-L1 and HER-2 as routine biomarkers in gastric cancer (GC). However, little research has been done to investigate the correlation among PD-L1, HER-2, and clinical features in GC. Methods Between Jan. 2013 and May 2020, a total of 120 GC patients treated with chemotherapy were admitted to Henan Tumor Hospital. We retrospectively identified PD-L1, HER-2 level before chemotherapy and abstracted clinicopathologic features and treatment outcomes. Univariate and multivariate survival analyses were performed to assess the relationship between PD-L1/HER-2 levels and progression-free survival (PFS). Results We retrospectively analyzed 120 patients with gastric cancer, including 17 patients with HER-2 positive and 103 patients with HER-2 negative GC. The results showed that the expression of PD-L1 was closely correlated with HER-2 gene status, with statistical significance (P =0.015). Patients with PD-L1/HER-2 positive obtained lower PFS compared to PD-L1/HER-2 negative (mPFS: 6.4 vs. 11.1 months, P=0.014, mPFS: 5.3 vs. 11.1 months, P=0.002). And the PD-L1 negative and HER-2 negative had the best PFS than other groups (P=0.0008). In a multivariate model, PD-L1 statue, HER-2 statue, tumor location and tumor differentiation remained independent prognostic indicators for PFS (P<0.05). Conclusion HER-2 status could predict the efficacy of immune checkpoint inhibitors, and HER-2 status combined with PD-L1 level could predict the prognosis of GC patients. Citation Format: Huifang Lv, Keran Sun, Caiyun Nie, Beibei Chen, Jianzheng Wang, Weifeng Xu, Saiqi Wang, Yingjun Liu, Junling Zhang, Shiqing Chen, Xiaobing Chen. Expression of HER-2 statue and PD-L1 is associated with prognosis in gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 766.