Overexpression of Platelet-derived Growth Factor-D as a Poor Prognosticator in Endometrial Cancer

Background: Emerging evidence implicates the platelet-derived growth factor-D (PDGF-D) in many types of human solid tumors. We investigated whether PDGF-D plays an important role in endometrial cancer (EC) in relation to clinicopathologic phenotype, angiogenesis, and patient prognosis. Materials and Methods: We analyzed PDGF-D protein expression by Western blotting in twenty-seven human endometrial cancer tissues, and matched normal endometrial controls collected at the third Affiliated hospital of Sun Yat-sen University during 2012-2013 (n=27). Immunohistochemical staining was performed using a human PDGF-D antibody on the endometrial cancer patients collected in the same facility during January 2001 and October 2013 (n=152). Patients were followed from the time of primary surgery in 2001-2013 until death or last follow-up. We correlated the PDGF-D expression levels with clinicopathologic parameters and prognosis in human endometrial cancer patients. Results: Compared with matched normal endometrial cases, PDGF-D was up-regulated in endometrial cancer. Expression of PDGF-D protein, found in 78% of the cases, was associated with nonendometrioid histologic type (p=0.028), FIGO stage III/IV (p=0.039), >50% solid tumor growth (p=0.048), pelvic LN metastasis (p=0.035) and ER and PR negativity (p=0.04 and 0.002). PDGF-D expression was also significantly associated with expression of VEGF-A (p=0.021). In multivariate analysis, PDGF-D expression proved to be an independent prognostic factor in addition to histologic grade and FIGO stage. Patients with high expression levels of PDGF-D had a significantly poorer overall survival rate compared with patients with no expression. Conclusions: PDGF-D expression is frequently up-regulated in endometrial cancer, and is associated with aggressive features and poor prognosis.