Expression of tissue factor is associated with clinical features and angiogenesis in prostate cancer.

Tissue factor (TF), the main initiator of blood coagulation, is involved in cancer metastasis and progression. We examined the role of TF on prostate cancer.Immunohistochemical analysis was performed using the anti-TF antibody. Intra-tumoral blood vessels were visualized by staining endothelial cells with CD34 antibody. We examined the expression of TF and the microvessel density (MVD) in 66 biopsy specimens of prostate cancer, in order to investigate the relationship between the expression of TF and the clinicopathology of prostate cancer.TF antigen was positive in 41 (62%) of the specimens. There were significant differences in TF expression according to the pretreatment prostate specific antigen (PSA) level (p = 0.0193) and bone metastasis (p = 0.0029). MVD was significantly related to bone metastasis (p = 0.0175). TF-positive carcinomas more frequently presented high MVD expressions (p = 0.017) than TF-negative tumors.These results suggest that increased angiogenesis associated with TF expression might cause the metastasis and progression of prostate cancer.