Dr. Chen’s lifetime research unveiled the cause-and-effect relationship between viral hepatitis, cirrhosis, and hepatocellular carcinoma (HCC), particularly in chronic hepatitis B (CHB). His important and insightful discovery and perspective eventually led to a global campaign for universal hepatitis B virus (HBV) vaccination, which has saved millions of lives across the world.

In addition to HBV, Dr. Chen had a wide interest in many aspects of viral hepatitis. Hepatitis C virus (HCV), the etiologic agent of non-A, non-B hepatitis, was first identified in 1989. In Taiwan, chronic hepatitis C (CHC) was primarily transmitted by blood transfusion and was ranked as the second most common etiology for HCC. However, no effective antiviral treatment was available in the early 1990s. In 1991, Dr. Chen and his colleague, Dr. Ming-Yang Lai, pioneered a clinical trial to demonstrate the superiority of the combination therapy using interferon (IFN) plus ribavirin in comparison with IFN alone. This novel combinatorial antiviral regimen and later pegylated IFN plus ribavirin soon became the standard of care for CHC until the emergence of direct-acting antiviral agents. In addition, Dr. Chen also cooperated with Dr. Jin-Chuan Sheu to use ultrasonography for diagnosis of small HCC, demonstrating its ability for early detection of HCC. Routine ultrasonographic examination for HCC is now an effective measure to improve diagnosis and clinical outcomes. Moreover, Dr. Chen and Dr. Jin-Town Wang discovered GB virus-C (also named hepatitis G virus [HGV]) in a longitudinal post-transfusion hepatitis cohort and proved that GBV-C did not cause hepatitis.