Stromal PDGFRβ Expression in Prostate Tumors and Non-Malignant Prostate Tissue Predicts Prostate Cancer Survival

Background: The identification of new prognostic markers for prostate cancer is highly warranted, since it is difficult to identify patients requiring curative treatment. Data from both experimental models and clinical samples have identified important functions of PDGFR beta on pericytes and fibroblasts in the tumor stroma. Methodology/Principal Findings: In this study the prognostic significance of PDGFRb in prostate cancer stroma, and in matched non-malignant tissue, was evaluated with immunohistochemistry. PDGFRb expression was analyzed in normal and tumor stroma from more than 300 prostate cancer patients. High PDGFR beta expression in tumor stroma was associated with large tumor size, advanced stage, high Gleason score and high vessel density. Perivascular PDGFR beta staining in tumors was also correlated with high Gleason score. Correlations were also observed between PDGFR beta status in tumor stroma and nonmalignant stroma. Similarly, high PDGFR beta expression in adjacent non-malignant tissue stroma correlated with large tumor size, advanced stage, high Gleason score and proliferation in non-malignant epithelium. Interestingly, high levels of PDGFR beta in the stroma of tumor and non-malignant tissue were associated with shorter cancer specific survival in prostate cancer patients. Conclusions/Significance: The study revealed a number of novel associations between stromal PDGFR beta expression in prostate tumors and several important clinical characteristics, including survival.