➤ Patients with past HBV receiving anticancer therapies associated
with an established high risk of HBV reactivation, such as anti-CD20
monoclonal antibodies or stem cell transplantation, should be started
on antiviral prophylaxis at the beginning of anticancer therapy and
continued on antiviral therapy for at least 12 months after the cessation
of anticancer therapy.
• HBV DNA should be obtained at baseline and followed every 6 months during
antiviral therapy.
• Patients with a negative anti-HBs may be at higher risk of HBV reactivation than
patients who have a positive anti-HBs.
• An alternative pathway is careful monitoring with HBsAg and HBV DNA every
3 months with immediate antiviral therapy at the earliest sign of HBV reactivation
(appearance of HBsAg or HBV DNA ≥1000 IU/mL) so long as patients and
providers are able to adhere to frequent and consistent follow up during anticancer
therapy and for up to 12 months after last anticancer therapy (as delayed HBV
reactivation may occur years after cessation of anticancer therapy).
• If HBV DNA that is quantifiable but <1000 IU/mL, then repeat testing at monthly
intervals may be indicated.
• Hepatitis flares, presenting as elevated ALT levels, can occur after the discontinuation
of antiviral therapy.
▶ As such, ALT levels should be monitored frequently, at least monthly for the first
3 months after the cessation of antiviral therapy and every 3 months thereafter.
(Strong recommendation; IC-B)
➤ Patients with past HBV undergoing anticancer therapies that are not
clearly associated with a high risk of HBV reactivation (e.g., regimens
that do not include anti-CD20 monoclonal antibodies or stem cell
transplantation) should be followed carefully during cancer treatment,
with HBsAg and ALT testing every 3 months (with subsequent HBV DNA
testing if a hepatitis flare develops) with initiation of antiviral therapy
only if HBsAg becomes positive or HBV DNA exceeds 1000 IU/mL in the
setting of a hepatitis flare.
Note: Follow-up testing after the cessation of anticancer therapy is likely not necessary.
(Strong recommendation; IC-B)
