Abstract: Objective：To detect the expression of Annexin A8 (ANXA8) in ovarian tissues and to investigate the relationship between its expression and clinicopathological parameters as well as prognosis in patients with ovarian epithelial serous carcinoma. Methods：Immunohistochemical (IHC) staining (SP method) for ANXA8 was conducted on tissues of 11 cases of normal ovaries, 13 cases of benign serous ovarian tumors, 17 cases of borderline serous ovarian tumors and 34 cases of malignant epithelial serous ovarian tumors, IHC results were compared to the clinical pathological parameters and prognosis of these malignant tumors. Results：The expression of ANXA8 was mainly located in cell membrane and cytoplasm, its high positive expression rate in epithelial serous ovarian carcinoma (23/34, 67.65%) was significantly higher than those in normal (1/11, 9.09%), benign (3/13, 23.08%) and borderline (5/17, 29.41%) epithelial serous ovarian tumors (P=0.001, 0.006, 0.010, respectively). Among these 34 cases of epithelial serous ovarian carcinoma, the high positive expression rate of ANXA8 in FIGO Stages Ⅲ-Ⅳ (21/24, 87.5%) was significantly higher than Stages Ⅰ-Ⅱ (2/10, 20.0%), P＜0.001; and the high positive expression rate of ANXA8 in patients with residual tumor size ＞1 cm (15/17, 88.2%) was significantly higher than ≤1 cm (8/17, 41.2%), P=0.010. Kaplan-Meier survival analysis showed that FIGO stage, lymph node metastasis, residual tumor, as well as high expression of ANXA8 were associated with a shorter overall survival (OS, all P＜0.05), multivariate Cox survival analysis demonstrated that high expression of ANXA8 was an independent risk factor for prognosis of epithelial serous ovarian carcinoma patients (P=0.019, HR=11.465, 95%CI: 1.498-87.757). Conclusions：The expression of ANXA8 was obviously increased in epithelial serous ovarian cancer and associated with poor prognosis of ovarian carcinoma, it can be used for clinical monitoring of patients with epithelial serous ovarian carcinoma.

Key words: Ovarian neoplasms, Annexins, Immunohistochemistry, Ovarian epithelial serous tumors, ANXA8