Abstract 5379: Prognostic significance of STING expression in patients with resected lung adenocarcinoma.

Abstract Background: Lung cancer is the leading cause of cancer death worldwide. Tumor recurrence is the most common cause of treatment failure after surgical resection. STING (Stimulator of Interferon IFN Genes) is a protein responsible for controlling anticancer immune responses to leaked self- or non-self DNA. Recent studies have shown in animal models that knocking out STING and cGAS expression results in a nonresponse to PD-L1 checkpoint therapy. STING and cGAS are thus thought to be essential for the antitumor response of PD-1/PD-L1 checkpoint inhibition. Several studies have reported that STING expression was decreased in tumor in hepatocellular, gastric and colorectal cancer, and in melanoma. STING is frequently lost during tumor progression, and loss of STING/cGAS correlates with poor survival. The prognostic value of STING expression in patients with resected lung adenocarcinoma has not been well demonstrated. Methods: A total of 68 patients with resected lung adenocarcinoma were included in the study. STING expression was determined by immunohistochemistry in tumor specimens. The prognostic value of STING expression and its relationship with clinicopathological variables were investigated. We have screened the expression of STING in several lung cancer cell lines. STING knockdown or transfection will be performed in suitable lung cancer cell lines. Western blotting analysis will be performed to demonstrated STING, E-cadherin and vimentin expression. Results: High STING expression was shown in 45 (66.2%) of the 68 lung tumor samples. Predominant pattern group (lepidic/acinar/papillary vs. micropapillary/solid) (P = 0.662) was not significantly associated with STING expression. Univariate analysis indicated that high STING expression (HR, 0.158; 95% CI, 0.032 to 0.787; P = 0.024) was a significant prognostic factor for better disease-free survival (DFS). In multivariate analysis, predominant pattern group (lepidic/acinar/papillary vs. micropapillary/solid) (HR, 5.764; 95% CI, 1.054 to 31.537; P = 0.043) was a significant prognostic factor for DFS. High STING expression (HR, 0.073; 95% CI, 0.009 to 0.617; P = 0.016) was also a significant prognostic factor for better DFS. Conclusions: High STING expression was a significant prognostic factor for better DFS in patients with surgical resected lung adenocarcinoma. This information is useful to stratify high-risk patients of recurrence after resection of lung adenocarcinoma. Citation Format: Jung-Jyh Hung, Ying-Shiun Kao. Prognostic significance of STING expression in patients with resected lung adenocarcinoma abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 5379.