[1126] Stromal Signatures in Endometrioid Endometrial Carcinomas

Inigo Espinosa, Emanuela D´Angelo, Ana Mozos, Belen Canet, Luis Catasus, Jaime Prat. Hospital de la Santa Creu i Sant Pau. Institute of Biomedical Research (IIB Sant Pau). Autonomous University of Barcelona, Barcelona, Spain

Background: The pattern of myometrial invasion in endometrioid carcinomas varies considerably; i.e., from widely scattered glands and cell nests, often associated with stromal desmoplasia, to invasive glands with little or no stromal response. Recently, two distinct stromal signatures, derived from a macrophage-response (CSF1) and a fibroblastic-response (DTF), were identified in breast carcinomas and correlated with clinicopathologic features including outcome. In this study, we explored whether these stromal signatures also apply to endometrioid carcinomas and if the aforementioned expression patterns correlated with morphologic changes.
Design: Stromal signatures were studied by immunohistochemistry on a tissue microarray of 88 endometrioid carcinomas. A case was considered to carry the CSF1-response signature if it showed coordinate expression of CD163, CD16, and CD32. Similarly, co-expression of SPARC and MMP11 was required for inclusion in the DTF-stromal signature group.
Results: Desmoplasia correlated positively with DTF expression signature. Likewise, CSF1 expression signature correlated strongly with the presence of mononuclear infiltrate. The DTF and CSF1 groups accounted for 17 % each of the total (15 of 88). Another 12 cases were positive for both DTF and CSF1 signatures (12/88; 13%). However, over half of the cases (46/88; 53%) failed to express any of the stromal signatures.

Stromal Signatures in 88 Endometrioid Carcinomas

Macrophage response signature (CSF1)	Fibroblast response signature (DTF)	Cases (%)
+	-	15/88 (17%)
-	+	15/88 (17%)
+	+	12/88 (13%)
-	-	46/88 (53%)

The macrophage response (CSF1) was associated with higher tumor grade and PIK3CA mutations (P =0.000). In contrast, tumors that evoked little or no inflammatory stromal response were low-grade and had a low rate of vascular invasion and PIK3CA mutations (P =0.000).
Conclusions: This study is the first characterization of stromal signatures in endometrioid carcinomas. Our findings shed new light on the relationhip between genetically different endometrioid carcinomas and various types of stromal response.
Category: Gynecologic & Obstetrics

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 171, Tuesday Morning