The sensitivity and specifity of DR-70 as a tumor marker for gastrointestinal cancers.

Abstract

e22061 Background: There is a great need to detect gastrointestinal cancers at an early stage, reduce morbidity and mortality. CEA and CA 19-9 are widely used serological markers for gastrointestinal cancers during follow-up. Their utility are limited because of their low sensitivity. In this study, a novel tumor marker DR-70 is evaluated for the sensitivity and specificity, relationship between clinical parameters and compared with CEA and CA 19-9. Methods: Blood sera of 101 histologically proven gastrointestinal cancer patients (38 female, 63 male; 42 colon, 25 rectum, 18 stomach, 9 pancreas, 4 esophagus and 3 cholangiocellular carcinomas) and 105 healthy blood donors were included. The TNM stage of the disease and histologic grade was shown. All patients and controls were also tested for CEA and CA 19-9 levels. In DR-70 immunoassay, the fibrin degradation products were quantitatively measured using ELISA DR-70 kits. Results: The median DR-70, CEA and CA19-9 levels were 1.6 µg/mL, 3.05 ng/mL and 22.2 IU/L in cancer patients, they were lower in healthy control 0.5 µg/mL, 0.9 ng/mL, 1.9 IU/L; p < 0.001. While the stage and grade increased, the levels of DR-70, CEA and CA-19-9 (p < 0.05) were increased significantly. DR-70 and CA19-9 values were highest in patients with pancreas, and lowest in rectum cancer, there was no statistically significant difference between tumor localization and CEA levels.The sensitivity, specificity and the cut-off value of DR-70, in patients with malignancy by using ROC analysis were found as 97%, 95% and < 0.75 µg/mL, respectively. The positive and negative predictive values were 95%, and 97% and the efficacy was 96%. Sensitivities of CEA (cut off value 3ng/mL) and CA 19-9 (cut off value 37 U/ml) were 52% and 39% respectively, the specificities were 94% and 99% for CEA and CA 19-9, respectively; sensitivity increased by combined use of both of them. Conclusions: Due to its high sensitivity and specificity, high positive and negative predictive values DR-70 can be used more frequently as a tumor marker for detection of gastrointestinal cancer. It can also be used in tumor progression and treatment follow-up because of positive correlation between DR-70 levels and the tumor stage.