Abstract
Objective: To investigate the expression of ARID1A in malignant neoplasms arising from the epithelium of the ovary and determine its relationship with tumor grade and stage.
Methodology: This cross-sectional study was carried out from January 2022 to December 2023, and included 71 histopathologically confirmed cases of epithelial ovarian cancer (EOC) after histological grading and staging based on FIGO criteria. Immunohistochemistry was performed with monoclonal rabbit antibody Tinto ARID1A (EP303) RMab Bio SB to detect nuclear ARID1A expression, which was categorized as positive or negative. The Chi-square test was performed to assess the correlation between ARID1A expressions with tumor grade and FIGO stage.
Results: The mean age of the participants was 43.6 years (range: 25-78), 37 were premenopausal, and 34 were postmenopausal women. Tumor size varied between 1.2 and 32.0 cm (mean 11.8 cm), and the ovarian capsule was ruptured in 42 cases. Among the tumors, 27 (38.0%) were FIGO stage I, 19 (26.8%) stage II, and 25 (35.2%) stage III. High-grade tumors were 44 (62.0%) cases. 45 (63.3%) cases were positive, and 26 (36.6%) were negative for ARID1A expression. Positive ARID1A expression was associated with reduced tumor grade and an early FIGO stage (p=0.034 and p=0.0097, respectively).
Conclusion: ARID1A may play a significant role in the development and progression of EOC. Positive ARID1A expression was associated with better clinical outcomes, while negative ARID1A expression was associated with poor prognostic factors.

Key words: ARID1A, epithelial ovarian cancer, immunohistochemistry, tumor grade, FIGO Stage.