According to the World Conference on Breast Cancer, 400,000 people die annually from this disease.It has been the most common cancer among women and an important cause of illness and death.PDGF-C was recently discovered and was found to be an EWS/FLI induced transforming growth factor, highly expressed in many tumor cell lines but their expression in primary tumors are less well known.In this study, we have investigated PDGF-CC expression in a small-scaled tumor tissue array in comparison with normal tissues and observed that PDGF-CC was highly expressed in tumor epithelia.We thus set up two collaborations with huge amount of breast tumor tissue constructed tissue array.A large (2300) tissue microarray based cohort of breast cancer was immunostained with PDGF-C monoclonal antibody on an automated IHC system.Epithelial and stromal expressions were semi-quantitatively evaluated by pathologists.Statistics were calculated using Spearmans rank correlation and KM-Analysis.PDGF-C is seen in cytoplasm of epithelial and stromal cells comprising capillaries and myofibroblasts.In invasive breast cancer, about 55% of cases evaluated so far displayed an epithelial expression.Both staining qualities were significantly correlated and were both associated with higher tumor grade.This analysis indicated the independent prognostic value of epithelial PDGF-C expression in breast cancer.The prognostic value of PDGF-C appears to be promising and very implicative with poor prognosis.From the above study, we concluded that PDGF-C may have a role in breast tumor development and our data clearly show the correlation between high epithelia PDGF-CC and poor prognosis and that may indicate a potential target for therapeutic value.