Introduction. The well-documented role of the PDGF system in tumor growth and angiogenesis has prompted the development of new biological agents targeting the PDGF system. The aim of the present study was to analyze the expression of the PDGF-receptors in ovarian cancer and to investigate its relation to histopathological parameters and long-term overall survival. Methods. The immunohistochemical expression of PDGFR-α and PDGFR-β was investigated in tumor and stromal cells in 170 patients with histologically verified epithelial ovarian cancer. Results. Almost half of the tumor specimens showed high expression of PDGFR-α and PDGFR-β in tumor cells (43% and 41%) and in stromal compartments (32% and 44%). There was a significant association between high expression of PDGFR-α and high expression of PDGFR-β in both tumor and stromal cells. Coexpression of PDGFR-α and PDGFR-β in stromal cells was seen more often in serous adenocarcinomas than in nonserous adenocarcinomas. No clear correlation between PDGFR expression and longterm overall survival or clinical parameters was found. Conclusions. PDGFR-α and PDGFR-β were expressed in a subset of ovarian carcinomas but did not show significant prognostic importance in this material. 1. Introduction Epithelial ovarian cancer is the most deadly gynecologic cancer in the Western world. The majority of patients are diagnosed in advanced stage which is a contributory factor to the poor prognosis of the disease. The current state- of-art in front-line treatment is aggressive surgical debulking followed by a combination of chemotherapy with platinum/taxane [1, 2]. Even though high response rates are seen, relapse often occurs within few years, and, in most cases, the therapy will then change from a curative to a palliative perspective. A higher degree of individualized treatment strategies based on validated prognostic or predictive markers may help improve the outcome and are therefore highly warranted in ovarian cancer. Results from recently published studies have shown that the addition of antivascular endothelial growth factor (VEGF) treatment to first-line chemotherapy may be beneficial for a fraction of ovarian cancer patients [3, 4], also in the treatment of the recurrent disease [5–7]. However, several other growth factors are involved in angiogenesis [8], among them the platelet-derived growth factor (PDGF) system. It plays a role in cell growth [9], chemotaxis [9, 10], pericytes recruitment, and stabilization of microvasculature [11, 12] as well as in the recruitment of fibroblast in tumor stroma [13, 14]. The
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