Loss of Nuclear ARID-1A Expressions Is Associated with Hormone Receptor Status in Breast Cancers.

Objective: Breast cancer is the most common cancer among women. worldwide. Adenine thymine-rich interactive domain 1A (ARID1A.) is a tumor suppressor gene involved in chromatin remodeling and it encodes the ARID1A protein. Recent studies have shown the loss of ARID1A protein expression in different carcinomas may have a prognostic significance. In the present study, we aimed co evaluate the interactions between ARID1A loss and molecular subtypes of breast carcinomas. Materials and Methods: ARID1A expressions were studied in 292 formalin- fixed, paraffin- embedded breast carcinoma specimens and its association with different pathological and clinical parameters was evaluated. Results: Loss of ARID1A expression was detected in 123 cases. There was no statistically significant association between ARID-1A expression and molecular subtype of breast carcinomas (p=0.110) or HER2 amplification (p=0.909). Contrarily, there was a significant association between ARID1A expression and presence of estrogen (p=0.047) or progesterone receptors (p=0.023). Besides a statistically significant relationship was found between loss of ARID1A, and the presence of both in situ component (p=0.016) and lymph node metastasis (p=0.001). Conclusion: In this study, we have demonstrated that loss of ARID1A expression positively correlates with hormone receptor status as well as tumor aggressiveness.