Proliferation and maturation of intratumoral blood vessels in women with malignant ovarian tumors assessed with cancer stem cells marker nestin and platelet derived growth factor PDGF-B

Objectives: Platelet-derived growth factor B (PDGF-B) and nestin have been suggested to be useful in the assessment of neoangiogenesis in malignant ovarian masses. We aimed to investigate a possible association of these markers with newly formed microcapillaries and perivascular cells in ovarian tumors. Material and methods: Microvessel density (MVD) and pericytes were studied in 82 women with ovarian neoplasms, including 7 benign cysts, 7 borderline masses, 64 epithelial ovarian cancers and 4 other malignant ovarian tumors. Immunohistochemical staining included antibodies to CD34, PDGF-B and nestin. Results: Median values of CD34-positive and nestin- positive MVD were: 24,5 (range: 17-32) and 21 (range: 12-31), respectively. No significant correlation between intratumoral CD-34 positive MVD and nestin-positive MVD was found. Benign and borderline lesions more frequently than malignant tumors displayed low or medium values of nestin- positive MVD (p = 0.01). Histological grading of malignant tumors was associated with nestin-positive MVD (p = 0.01). Nestin expression in tumor cells was not correlated with tumor grade or histological subtype. PDGF-B expression was found in tumor microvessels in 72% of cases (59/82). High expression of PDGF in pericapillary cells was strongly associated with high expression of this marker in cancer cells (p = 0.007). Significant correlations between PDGF-B and nestin expression in malignant tumor microvessels were also found (p = 0.04). Nestin and PDGF-B expressions were strongly associated with high grade tumors when compared to low grade or benign masses. Conclusions: We conclude that the assessment of PDGF-B and nestin-positive MVD could be used to identify only highly active, angiogenic malignant ovarian masses, where tumor vasculature is formed.