mTOR Expression Is Not Associated with FIGO Grade in Uterine Endometrioid Carcinoma.
Joanna SY Chan, Lora H Ellenson. NYP Weill Cornell Medical Center, New York City, NY
Background: Endometrial carcinoma is the most common cancer of the female genital tract in the US. Currently, there are few molecular prognostic markers. Our previous research has shown that while phosphatidylinositol 3-kinase (PI3K) mutations are common in uterine endometrioid carcinoma (UEC), they do not correlate with FIGO grade. Mammalian target of rapamycin (mTOR) is a growth regulator associated with activation of the PI3K pathway. Previous studies are discordant in proof of mTOR's use as a prognostic marker. In this study, we evaluated UEC for expression of mTOR, to further evaluate mTOR as a possible prognostic marker.
Design: A tissue microarray was constructed using tumor tissue from 68 cases of UEC grade I, 66 cases of UEC grade II, and 55 cases of UEC grade III. Samples of proliferative and secretory endometrium were also included in the analysis. mTOR expression was detected using standard immunohistochemical staining with rabbit monoclonal mTOR antibody (clone 49F9, Cell Signaling technology). A previously described staining index was calculated as the product of staining intensity (0-3) and extent of staining (1=1-10%, 2=11-50%, 3=51-80%, and 4=81-100%) to grade each sample. Institutional IRB approval was obtained for this study.
|FIGO Grade||Average mTOR score||Range of Score|