[Expression of SMARCA4(BRG1) and SMARCB1(INI1) in dedifferentiated and undifferentiated endometrial carcinomas and their correlations with clinicopathological features].

Objective: To investigate the expression of SMARCA4 (BRG1) and SMARCB1 (INI-1) protein in endometrial dedifferentiated carcinoma (DDC) and undifferentiated carcinoma (UDC), and their correlation with clinicopathologic features. Methods: Clinicopathological information was gathered for 26 cases of DDC and UDC and consulting hospitals from January, 2006 to December, 2018 in Fudan University Shanghai Cancer Center, including 10 cases of DDC and 16 cases of UDC. Morphologic features and diagnosis were reviewed by two pathologists. Immunohistochemistry for expression of BRG1 and INI1 protein was performed. The correlations with clinicopathologic features were analyzed. Results: BRG1 and INI1 loss were present in 14 of 26 cases of DDC/UDC, including 12 BRG1-deficient cases and 2 INI1-deficient cases, respectively. Six cases demonstrated variable amounts of rhabdoid cells in 14 BRG1/INI1-deficient cases, and only 1 case showed rhabdoid cells in the 12 intact expression cases. However, there was no significantly statistical difference (P=0.060). Age, invasive depth, lymph node status and FIGO stage were not associated with the expression of the BRG1 and INI1 (P=0.437, P=0.672, P=0.242, P=0.348). Remarkably, the BGR1/INI1-deficient patients had worse survival than those with intact expression (4.7 vs. 22.9, P=0.033). Conclusion: BRG1/INI1-deficient is observed in approximately half of DDC and UDC. Identification of these tumors is clinically relevant due to their more aggressive behavior and poor prognosis. Hence, BRG1 and INI1 immunohistochemical stains should be performed for DDC and UDC in order to help the pathologists to distinguish these tumors from other carcinomas, and to predict the clinical prognosis.