Evaluation of serum thioredoxin as a hepatocellular carcinoma diagnostic marker

Hepatocellular carcinoma (HCC) is one of the most prevalent and fatal malignancies worldwide. Following an increase in reactive oxygen species (ROS), cancer cells enter an oxidative stress state. As a result, these cells experience an increase in antioxidant activity to counteract oxidative stress. The thioredoxin (TRX) system is a ubiquitous mammalian antioxidant system that neutralizes ROS and maintains intracellular reduction oxidation (redox) balance, which is essential for HCC growth. However, the role of TRX protein in HCC remains largely unknown. Hence, we aimed to assess the diagnostic utility of serum TRX in patients with HCC. A total of 50 patients were consecutively recruited in this observational study. They were classified into three groups: an HCC group (25 patients), a cirrhosis group (15 patients with liver cirrhosis on top of chronic HCV infection), and a control group (10 healthy individuals). Serum TRX levels were measured using ELISA. Higher serum TRX levels were detected in the HCC group than in the cirrhosis and control groups (140.96 ± 12.70 vs 88.33 ± 10.34 vs 73.10 ± 13.22 ng/mL, respectively; P < 0.001). TRX was independently associated with the presence of HCC (P < 0.001). Regarding the detection of HCC, TRX at a cut-off value of 114 ng/mL had superior diagnostic performance to AFP with an AUC of 1.000, sensitivity of 100%, and specificity of 100%, whereas AFP at a cut-off value of 20.5 ng/mL had an AUC of 1.000, sensitivity of 100%, and specificity of 47%. Thioredoxin has the potential to be an HCC diagnostic marker. The clinical significance of thioredoxin in HCC requires further investigation.