Objective: The objective was to evaluate the preoperative blood concentration of tissue plasminogen activator (tPA) as a discriminator between malignant and benign ovarian tumors, and as a potential marker of postoperative prognosis in patients with ovarian cancer.
Methods and material: The concentration of tPA was assayed with ELISA (Imulyse Biopool) in preoperative plasma samples obtained from 111 patients with adnexal lesions. Tumors were classified as benign (n = 25), borderline malignant (n = 11), well-differentiated (G1, n = 22), moderately differentiated (G2, n = 11), and poorly differentiated malignant (G3, n = 42). The median follow-up time of patients with malignant tumors was 5.6 years (range 2.1-13.2 years) and 37 patients died during the follow-up period.
Results: Patients with moderately and poorly differentiated tumors had higher levels of plasma tPA compared to those with well-differentiated tumors (P = 0.004 and P = 0.005). No significant differences in the plasma tPA levels were observed between patients with benign, borderline, and well-differentiated tumors. The tPA levels were not different between stages nor within stage Ia-c. In a multivariate Cox proportional hazards model including stage, grade, age, and plasma tPA dichotomized at the median (> or =9 vs <9 ng/mL), high levels of tPA were significantly associated with shorter survival: HR = 4.4 (95% CI 2.0-9.8, P = 0.0003). In the univariate analyze high levels of tPA showed HR = 4.5 (95% CI 2.1-9.6, P = 0.0003).
Conclusions: High concentration of plasma tPA was an independent marker for poor prognosis in patients with ovarian cancer in our study. Plasma tPA did, however, not discriminate between benign and malignant adnexal lesions.