Recurrence of Hepatocellular Carcinoma With Epithelial-Mesenchymal Transition After Spontaneous Regression: A Case Report.

Hepatocellular carcinoma (HCC) is one of the most malignant cancers and ranks as the third leading cause of cancer-related death in the world. However, some patients with untreated HCC can experience spontaneous regression, a rare phenomenon that has been observed in various malignancies. Here, we report a unique case with untreated HCC, who first underwent a spontaneous cancer regression after the spontaneous clearing of chronic hepatitis B virus (HBV) infection from the liver as evidenced by hepatitis B virus surface antigen (HBsAg) seroconversion; then developed the recurrent HCC with epithelial-mesenchymal transition (EMT) after 14 years. We hypothesized that a strengthened immune system in response to HBV infection may have led to immune-mediated spontaneous cancer regression. The later recurrence of HCC may suggest the host's immune system was no longer able to contain HCC since aging and other chronic diseases may have significantly weakened the immune surveillance.