化學治療的目標為治療或控制腫瘤以提高病人的存活率及生活品質為主，然而對於B 型肝炎帶原者而言，化學治療則可能導致B 型肝炎病毒再活化 (hepatitis B virus reactivation, HBV reactivation)，進而造成肝炎、肝衰竭的風險增加。本文探討一位因轉移性泌尿道移形上皮細胞癌 (transitional cell carcinoma of the urothelium) 接受化學治療的B 型肝炎帶原者，其在化療開始前血清免疫檢查顯示為HBsAg(+) 但無給予預防性抗病毒藥品，在化療治療過程中因發生B 型肝炎病毒再活化而導致急性肝炎，故暫停化療並以抗病毒藥品治療，直至肝功能恢復才重新化療同時持續使用抗病毒藥品的案例。並藉由文獻回顧，探討化學治療引發B 型肝炎病毒再活化之成因、可能性及處理方式。

The aim of chemotherapy is to treat or control the progression of cancer as away of increasing the survival rate and improving patients’ quality of life. However, chemotherapeutic agents may also induce hepatitis B virus reactivation, thereby posing a risk of hepatitis or hepatic failure in HBV carriers. This study reports an HBV carrier who suffered from acute hepatitis during her chemotherapy for the transitional cell carcinoma (TCC) of the urothelium. Before the treatment, this patient with HBsAg-positive was not given prophylactic antivirus drugs. After she started the treatment, hepatitis B virus reactivation occurred, resulting in acute hepatitis. Therefore, the patient was given continuous antivirus drugs while at the same time the chemotherapeutic agents were suspended. The chemotherapy was not re-launched until the patient’s liver function recovered. The purpose of this case report is to discuss the prophylaxis of HBV reactivation in chemotherapy patients.