Background and question: Malignant cells characteristically possess high levels of proteases (e.g. plasminogen activator, cathepsin etc.), which should induce fibrinolysis. The DR- 70(tm) immunoassay quantifies the amount of fibrin degradation products (FDP) in the body. This test system has successfully been used for the detection of a number of cancers including lung, stomach, breast, rectum, liver, colon and uterus cancer. In this paper we tested the diagnostic validity of DR- 70(tm) relative to CA- 125 as a tumor marker for the detection of ovarian carcinoma. Methods: We have simultaneously investigated the serum activities of DR- 70(tm)and CA- 125 from 61 preoperative patients with histologically confirmed ovarian carcinoma. One hundred healthy blood donors served as control group. We measured the FDP utilizing the DR- 70(tm) ELISA as per test instructions of its manufacturer AMDL (Tustin, CA, USA). Results: Low levels of FDP measured by DR- 70(tm) have been detected in the serum of 100 apparently healthy persons (mean ± S.D., 0.41 ± 0.19 μ g/ml). Among the 61 ovarian carcinoma patients, DR- 70(tm) mean value (± S.D.) was 7.0 ± 10.5 μ g/ml in a range of 0.6 to 58.5 μ g/ml. The cut- off level for DR- 70(tm) was set at > 1.2 μ g/ml. The specificity was 100% , whereas the sensitivity was at 83.6% . Relative to CA- 125 a cut- off level of > 65 U/ml was applied. The comparable sensitivity of DR- 70(tm) was higher by 13.1 % . Conclusions: Malignant cells with high levels of proteases are significant contributors to fibrinolysis. The DR- 70(tm) immunoassay has been designed to measure the level of FDP in the serum. DR- 70(tm) represents a tumor marker with which ovarian carcinoma can be diagnosed at levels of sensitivity and specificity which compare favorably to those measured with CA- 125. Background and question: Malignant cells characteristically possess high levels of proteases (eg plasminogen activator, cathepsin etc.), which should induce fibrinolysis. The DR-70 (tm) immunoassay quantifies the amount of fibrin degradation products (FDP) in the body. This test system has successfully been used for the detection of a number of cancers including lung, stomach, breast, rectum, liver, colon and uterus cancer. In this paper we tested the diagnostic validity of DR- 70 (tm) relative to CA- 125 as a tumor marker for the detection of ovarian carcinoma. Methods: We have been investigating the serum activities of DR-70 (tm) and CA-125 from 61 preoperative patients with histologically confirmed ovarian carcinoma. One hundred healthy blood donors served as control group . We measured the FDP utilizing the DR-70 (tm) ELISA as per test instructions of its manufacturer AMDL (Tustin, CA, USA). Results: Low levels of FDP measured by DR- 70 (tm) have been detected in the serumof the 100 apparently healthy persons (mean ± SD, 0.41 ± 0.19 μg / ml). The 61 ovarian carcinoma patients, DR-70 (tm) mean value (± SD) was 7.0 ± 10.5 μg / ml in a range of 0.6 to 58.5 μg / ml. The cut-off level for DR-70 (tm) was set at> 1.2 μg / ml. The specificity was 100%, while the sensitivity was at 83.6%. Relative to CA- 125 a The likely sensitivity of DR-70 (tm) was higher by 13.1%. Conclusions: Malignant cells with high levels of proteases are significant contributors to fibrinolysis. The DR-70 (tm ) immunoassay has been designed to measure the level of FDP in the serum. DR- 70 (tm) represents a tumor marker with which ovarian carcinoma can be diagnosed at levels of sensitivity and specificity which compare favorably to those measured with CA-125.