De novo Hepatitis B Virus Reactivation during Treatment with an Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor in a Patient with Advanced Lung Cancer.

A 71-year-old woman was treated with osimertinib for stage IV adenocarcinoma with epidermal growth factor receptor (EGFR) mutations. Treatment led to improvements in the primary tumor, multiple lung metastases, and multiple bone metastases. However, nine months later, she presented with marked liver dysfunction and jaundice. Chest and abdominal computed tomography did not show abnormal findings in the liver parenchyma or biliary system. However, blood tests were positive for hepatitis B surface antigen and hepatitis B virus DNA, suggesting hepatitis B virus reactivation. The patient died of liver failure despite treatment with steroids and antiviral drugs.