Tissue Expression of Neutrophil Gelatinase-Associated Lipocalin and Kidney Injury Molecule-1 in Breast Cancers.

Objective: Breast cancer is the most common cancer among women worldwide. Neutrophil gelatinase-associated lipocalin (NGAL) has important roles in immunity, cell proliferation, and carcinogenesis. Kidney injury molecule-1 (KIM-1) is a transmembrane glycoprotein also known as hepatitis A virus cellular receptor 1 and T-cell immunoglobulin and mucin, has restricted expression in immune cells and healthy epithelial cells, but it is up-regulated in several human cancers. The aim of this study was to determine the prognostic values of NGAL and KIM-1 expression in tumor cells and to detect the presence of NGAL-positive neutrophils (PNL) in the tumor microenvironment.

Materials and methods: The expression of NGAL and KIM-1 protein were assessed by immunohistochemical staining in tissue specimens from 412 primary breast cancer cases.

Results: In this series, the mean age of the patients was 55.6±12.4 years. In 218 (52.9%) cases, there was NGAL expression in tumor cells. In 104 (25.2%) cases there was KIM-1 expression in tumor cells. NGAL-positive inflammatory cells were seen in tumors of 45 (10.9%) cases. There was no significant relationship between NGAL-positive PNL presence in the tumor microenvironment and other clinicopathological features. However, there was a significant association between the presence of in situ carcinomas and NGAL expression (p = 0.008) and KIM-1 expression (p = 0.020) in tumor cells.

Conclusion: This study has demonstrated positivity of NGAL and KIM-1 in breast cancer cells. Considering the development of anti-KIM-1 therapies, the presence of KIM-1 expression may be a new treatment option in breast cancer, especially in in situ component-rich tumors. These findings should be confirmed in larger series.