Abstract
BACKGROUND: Heparanase is an endo-beta-D-glucuronidase that is capable of cleaving heparan sulfate (HS) side chains at a limited number of sites, yielding HS fragments of still appreciable size (approximately 5-7 kDa). Heparanase activity has been detected frequently in several cell types and tissues. Heparanase activity correlates with the metastatic potential of tumor-derived cells, a correlation that has been attributed to enhanced cell dissemination as a consequence of HS cleavage and remodeling of the extracellular matrix barrier. METHODS: In this study, the authors examined heparanase expression in 114 patients with lung cancer by means of immunohistochemistry and correlated clinical-pathologic data with heparanase immunostaining and cellular localization. RESULTS: Heparanase was overexpressed in 75% of the study patients. Heparanase expression was correlated with lung cancer lymph node status and metastasis classification (P = .04 and P = .01, respectively) and was correlated inversely with patient survival (P = .007). It is noteworthy that this adverse effect depended largely on the cellular localization of heparanase. Thus, whereas cytoplasmic staining of heparanase is associated with a poor prognosis, nuclear heparanase predicts a favorable outcome for patients with lung cancer. CONCLUSIONS: The current findings suggest that heparanase expression and cellular localization are decisive for lung cancer patients' prognosis, most likely because of heparanase-mediated tumor cell dissemination by blood and lymph vessels.