RT - European Journal of Gynaecological Oncology ID - 10.31083/j.ejgo4206166 T1 - ARID1A and GPR30 expression patterns characterize the different histological subtypes of endometrial carcinoma A1 - Wiktor Szewczuk A1 - Oksana Szewczuk A1 - Krzysztof Czajkowski A1 - Barbara Górnicka A1 - Barbara Górnicka A1 - Andrzej Semczuk K1 - Endometrial cancer; Immunohistochemistry; ARID1A; Nidogen 2; LRH-1; GPR30 YR - 2021 SP - 1138 AB -

Objectives: It is of utmost importance to investigate the newly discovered immunohistochemical proteins that are helpful in differentiating various histological subtypes of endometrial carcinomas (ECs). In this study, we aimed to compare the localization and expression profile of selected proteins (ARID1A, nidogen 2 (NID2), LRH-1, and GPR30) in 60 early-staged (I and II) G2/G3 ECs with different histological subtypes. Methods: Endometrioid-type (n = 20), serous (n = 20), and clear-cell (n = 20) ECs were immunohistochemically stained applying the anti-ARID1A, -NID2, -LRH-1, and -GPR30 antibodies. Normal endometrial samples (n = 8) were selected as a control group. Results: In general, 95% (19 out of 20) and 100% (20 out of 20) of endometrioid and serous samples revealed moderately/intense cytoplasmic/nuclear ARID1A immune-positivity, while only four out of 20 (20%) clear-cell carcinomas showed moderate staining. A significant difference in ARID1A expression was noted between different histological subtypes of ECs (clear-cell cancer vs endometrioid cancer, p < 0.001, and clear-cell cancer vs serous cancer, p < 0.001). Cytoplasmic NID2 staining did not differ significantly between histological subtypes. Most of the endometrioid (19/20; 95%) and serous (19/20, 95%) neoplasms revealed intense cytoplasmic LRH1-immunopositivity. Weak/moderate GPR30 cytoplasmic reactivity was detected in 16 out of 20 (80%) endometrioid EC, however, this protein was neither noted in clear-cell and serous neoplasms nor normal endometria. Differences in GPR30 immunoreactivity between endometrioid cancer and serous/clear-cell cancer were of significant values (p < 0.005). Conclusion: Weak ARID1A expression may be associated with gene alterations in selected EC histological subtypes. GPR30 staining may help to differentiate various histological EC subtypes.