Prevention and management of hepatitis B virus reactivation in cancer patients.

Hepatitis B virus (HBV) reactivation during immunosuppressive therapy is common in patients with solid tumor or hematological malignancies. It is associated with significant morbidity and mortality due to hepatitis flare and/or hepatic decompensation. These consequences arising from HBV reactivation are, however, largely preventable. Routine screening for HBV serologic status is recommended for all cancer patients undergoing chemotherapy or biologics. By recognizing different serological patterns (which represent either overt or occult HBV infection) and the types of immunosuppressive therapies prescribed, a risk-adapted approach can be established. Prophylactic therapy with nucleos(t)ide analogues (prior to or concomitantly with the commencement of immunosuppressive therapies) is more effective than pre-emptive therapy (starting antiviral when HBV DNA level is rising) in high-risk individuals. Entecavir has been proven to be more effective than lamivudine according to recent studies. Close monitoring of serum HBV level is the preferred strategy in low-risk patients. However, the optimal interval of DNA monitoring and the duration of therapy remain unknown.