Blood protein biomarkers in hepatocellular carcinoma: progress and challenges

Hepatocellular carcinoma (HCC) is an important cause of cancer-related death. Due to the lack of typical clinical symptoms in early-stage HCC, most HCC patients are diagnosed at an advanced stage and have lost the opportunity of surgery, which results in a poor prognosis. Therefore, early detection and timely intervention are the most effective methods to reduce the mortality of HCC. Blood flows through different organs and tissues, and there are abundant tumor biomarkers in blood, which can provide real-time information for the early diagnosis and prognostic prediction of HCC, so blood tumor biomarkers have become an effective supplement to imaging technology. As the most ideal biomarkers for disease diagnosis, serum and plasma proteins have been the main focus for biomarker development. In this review, we summarized the research progress of potential blood protein biomarkers (tumor-associated antigens and tumor-associated autoantibodies) in HCC and discussed their obstacles in clinical translation.