['Tissue factor (TF) is a procoagulant that plays an important part in tumor angiogenesis. We sought to determine the role of preoperative serum TF levels in predicting clinical outcome in patients with ovarian cancer.', 'TF expression was determined by reverse transcriptase polymerase chain reaction in ovarian cell lines. Using enzyme-linked immunosorbent assay, we assessed preoperative serum TF levels in 98 women with invasive epithelial ovarian carcinoma, 30 with low malignant potential (LMP) tumors, 16 with benign tumors, and a separate validation group of 39 women with adnexal masses. Clinical information was gathered from chart review.', 'TF was expressed in four of the five ovarian cancer cell lines, but absent in the nontransformed cells. Ovarian cancer patients had a median preoperative serum TF level of 85.2 pg/mL, which was significantly higher than in those with LMP tumors (12.8 pg/mL; P < .01) and benign adnexal disease (30.7 pg/mL; P < .01). TF >or= 190 pg/mL was significantly associated with decreased patient survival (P < .01). After adjusting for other clinical variables in a multivariate Cox regression model, TF >or= 190 pg/mL was an independent prognostic factor (P < .01). Analysis of serum TF levels from the validation set confirmed that high TF (>or=190 pg/mL) was associated with a 3.4-fold increase in risk of death from disease (P = .02) and shorter survival (P = .01).'] Are preoperative serum tissue factor levels an independent prognostic factor in patients with ovarian carcinoma?