Abstract 1737: Lipocalin-2/NGAL expression is associated with poor prognostic variables in human mammary, endometrial and ovarian carcinomas

Abstract BACKGROUND: Recent literature has shown that lipocalin-2, a lipophilic ligand transporter member of the lipocalin family has a possible role as a biomarker and a modulator of human cancers. Elevated levels of lipocalin-2 have been demonstrated in several types of human cancer. However, its role as a prognostic biomarker has not been widely reported. DESIGN: Formalin-fixed, paraffin-embedded tissue sections from 146 invasive mammary, 124 endometrial and 59 ovarian carcinomas were immunostained by automated method (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 78/146 (53%) of invasive mammary carcinomas and correlated with PR positive status [63% PR positive versus 41% PR negative, p=0.012] and disease recurrence [69% recurrent versus 48% non-recurrent, p=0.021). On multivariate analysis, advanced stage, lipocalin-2 overexpression, ER negative status, metastatic disease at diagnosis and positive node status were independent predictors of disease recurrence; while advanced stage, metastatic disease at diagnosis and positive node status were independent predictors of shortened survival. In endometrial carcinomas, cytoplasmic lipocalin-2 overexpression was observed in 47/124 (38%) tumors, and correlated with tumor grade (52% grade 3 vs. 43% grade 2 vs. 21% grade 1, p=0.045) and with ER negative status [52% ER negative vs 28% ER positive, p=0.049]. There was no correlation with disease recurrence or overall survival. In invasive ovarian carcinomas, cytoplasmic lipocalin-2 overexpression correlated with tumor grade (0% grade 1 vs. 40% grade 2 vs. 67% grade 3, p=0.006) and advanced tumor stage (32% stage I vs. 65% stage III vs. 100% stage IV, p=0.018). Lipocalin-2 expression did not correlate with patient survival. CONCLUSION: Lipocalin-2 overexpression correlates with varying markers of biologic aggressiveness in human mammary, endometrial and ovarian carcinomas warranting further study. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1737.