Expression and prognostic significance of platelet-derived growth factor and its receptors in epithelial ovarian neoplasms.

The expression of platelet-derived growth factor (PDGF), PDGF-alpha receptor (PDGFR alpha) and PDGF-beta receptor (PDGFR beta) was studied in normal ovaries and ovarian neoplasms by immunohistochemical analysis. PDGF was detected in tumor cells in 33 of 45 malignant tumor samples but in none of 20 benign tumors (P < 0.001) or 11 normal ovaries (P < 0.001). In borderline tumors, 4 of 7 tissues stained positive in tumor cells. PDGFR alpha was detected in tumor cells in 16 of 45 malignant tumors, while no epithelial staining was found in 16 benign tumors (P = 0.002) or in 10 normal ovaries (P = 0.023). In 1 of 7 borderline neoplasms, tumor cells expressed PDGFR alpha. Neither normal epithelium nor tumor cells stained positive with antibodies against PDGFR beta. Patients with ovarian cancer and PDGFR alpha-positive tumor cells demonstrated an overall shorter survival compared to those who had negatively stained tumors (P < 0.005). A similar correlation was found in patients having stage III ovarian cancer (P < 0.01), which further supports an independent role for PDGFR alpha as a prognostic factor. Thus, the concomitant expression of PDGF and PDGFR alpha in tumor cells is related to progression of malignant ovarian tumors, indicating a functional role of PDGF via autocrine growth stimulation.