Abstract:

INTRODUCTION: Development of gastric carcinoma is regulated by many factors. Adenin Timine rich interactive domain 1A (ARID1A) is a tumour suppressor gene involved in chromatin remodeling and it encodes the ARID1A protein. Recent studies have shown the loss of ARID1A expression in gastric carcinomas may have a prognostic importance. In our study, we purposed to evaluate the possible prognostic role of ARID1A loss in gastric carcinomas. METHODS: ARID1A expressions were studied in 113 formalin-fixed, paraffin-embedded gastric carcinoma specimens and its association with different pathological and clinical parameters was evaluated. RESULTS: The mean percentage of ARID1A stained cells was 55.42% (minimum=1%, maximum=100%). ARID1A expression was found 73.89% in pT1b, 54.22% in pT2, 53,76% in pT3, 53.92% in pT4 tumours respectively (p=0.219). ARID1A expression was averagely found 56.61% in poorly cohesive type tumours, 48.52% in tubular type, 80% in mucinous type, 73.75% in papillary type and 76.25% in mixed type tumours (p=0.093). ARID1A expression was found 61.23% in HER2 positive tumours and 53.22% in HER2 negative tumours (p=0.262). ARID1A expression was evaluated and compared with tumour localisation and other pathological parameters as lymph node metastasis, perineuronal invasion, lymphovascular invasion. Also they were not statistically significant. Contrary, there was significant association between ARID1A expression and survival of HER2 negative tumors (p=0.047). DISCUSSION AND CONCLUSION: Identification of specific biomarkers is very important for prediction of clinical outcome in gastric tumours. We demonstrated loss of ARID1A expression in HER2 negative gastric carcinomas positively correlate with overall survival. These results suggest that ARID1A may play a role in the biology of HER2 negative gastric carcinomas.

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