Hepatitis B reactivation in cancer patients: role of prechemotherapy screening and antiviral prophylaxis.

Hepatitis B virus (HBV) infection is a potentially life-threatening condition that can be effectively prevented by vaccination. In the United States, more than 1.5 million people are infected with HBV, and that number continues to rise with the arrival of immigrants from HBV-endemic countries. Cancer is the second leading cause of death in the United States; 1 in 2 men and women will be diagnosed during their lifetime, and a large proportion of them will require chemotherapy. Chemotherapy-induced immunosuppression can result in HBV reactivation in asymptomatic HBV carriers or patients with resolved HBV infection, causing severe morbidity and mortality. The rate of HBV reactivation depends on several factors, including host and viral factors, and varies from 3-88%. Mortality rates in HBV reactivation range from 23-71%. However, a recent US survey showed that 20% of practicing oncologists never perform any type of HBV screening before the initiation of chemotherapy, and less than 40% perform HBV screening in patients who have high-risk factors for HBV or a history of hepatitis. Given the magnitude of this clinical problem, it is very important to increase awareness among physicians regarding this potentially life-threatening complication. In this article, we review the current understanding of the problem, discuss the existing guidelines from professional societies, and outline a management plan.