Lipolcalin-2/NGAL Overexpression in Endometrial Carcinoma
D Cho, J Torres-Mora, CE Sheehan, JS Ross. Albany Medical College, Albany, NY
Background: Lipocalin-2, also known as neutrophil gelatinase associated lipocalin, is a 2k kDA glycoprotein that appears to function as a hydrophobic compound transporter. Upregulation of ipocalin-2 has been frequently described in a variety of inflammatory conditions involving numerous organs and tissues. Lipocalin-2 expression has not been widely studied in cancer and its role a prognostic biomarker for endometrial carcinoma has not been previously evaluated.
Design: Formalin-fixed, paraffin-embedded tissue sections from 124 endometrial carcinomas, including 101 endometrioid carcinoma (EC), 12 uterine papillary serous carcinoma (PSC) and 11 malignant mesoderm mixed tumor (MMMT) were immunostained by automated methods (Ventana Medical Systems Inc., Tucson, AZ) using rat monoclonal lipocalin-2/NGAL (R&D Systems, Minneapolis, MN). Cytoplasmic immunoreactivity was semiquantitatively scored based on staining intensity and distribution and the results were correlated with morphologic and prognostic variables.
Results: Cytoplasmic lipocalin-2 overexpression was observed in 47/124 (38%) tumors, including 37/101 (37%) EC, 6/12 (50%) PSC, and 4/11 (36%) MMMTs. Lipocalin-2 overexpression correlated with tumor grade (52% grade 3 vs. 43% grade 2 vs. 21% grade 1, p=0.045) and with ER negative tumors [52% ER negative vs 28% ER positive, p=0.049] overall and within the MMMT subgroup [100% ER negative vs 0% ER positive, p=0.046]. Within the ER negative subgroup, lipocalin-2 overexpression correlated with PR positive status [88% PR positive versus 31% PR negative, p=0.011] and showed a trend for association with depth of myometrial invasion (80% invading to more than 50% of the myometrium vs. 46% to less than 50% vs. 0% no invasion, p=0.088). There was no correlation with disease recurrence or overall survival.
Conclusions: Lipocalin-2 expression is associated with high grade endometrial carcinomas and may be a predictor of advanced tumor stage. Continued study of this biomarker in endometrial carcinoma cases appears warranted.
Category: Gynecologic & Obstetrics
Wednesday, March 24, 2010 9:30 AM
Poster Session V # 132, Wednesday Morning