What are the recommendations for Hepatitis B Virus (HBV) screening and management?

Recommendations for Hepatitis B Virus (HBV) Screening and Management

All patients with cancer anticipating systemic anticancer therapy should be screened for HBV with three tests—hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), and antibody to hepatitis B surface antigen (anti-HBs)—prior to starting treatment. 1

Screening Recommendations

Who Should Be Screened for HBV

1. Universal screening for specific populations:

   • All patients with cancer anticipating systemic anticancer therapy 1
   • All patients with hematologic malignancies and/or patients receiving hematopoietic stem cell transplantation 1
   • Pregnant women at their first prenatal visit 2
   • Populations with baseline prevalence exceeding 2% for chronic HBV 1

2. Risk-based screening:

   • Persons at moderate or high risk who will undergo immunosuppressive drug therapy 1
   • Persons with HIV infection 1
   • Persons who inject drugs 1, 3
   • Men who have sex with men 3
   • Household contacts of HBV-infected persons 3
   • Persons from countries with high HBV prevalence 3
   • Persons with a history of sexually transmitted infections or multiple sex partners 4
   • Persons with history of hepatitis C virus infection 4
   • Persons with incarceration history 4

3. Additional considerations:

   • Anyone who requests HBV testing should receive it, regardless of disclosure of risk 4
   • CDC now recommends HBV screening at least once during a lifetime for all adults aged ≥18 years 4

Recommended Screening Tests

• Complete screening panel includes:

  • Hepatitis B surface antigen (HBsAg)
  • Hepatitis B core antibody (anti-HBc) total or IgG
  • Antibody to hepatitis B surface antigen (anti-HBs) 1

• Follow-up testing:

  • If either HBsAg or anti-HBc is positive, perform a sensitive HBV DNA test 1

Interpretation of HBV Test Results

HBV Status	HBsAg	Anti-HBc	Anti-HBs
Chronic HBV infection	Positive	Positive	Negative
Past HBV infection (resolved)	Negative	Positive	Positive
Isolated core antibody	Negative	Positive	Negative

Management of HBV-Infected Patients

Chronic HBV Infection (HBsAg-positive)

1. For patients receiving any systemic anticancer therapy:

   • Initiate antiviral prophylaxis before starting immunosuppressive therapy 1
   • Continue antiviral therapy for the duration of anticancer therapy plus at least 12 months after completion 1
   • Monitor ALT and HBV DNA at baseline and every 6 months during antiviral therapy 1
   • After stopping antivirals, monitor ALT monthly for 3 months, then every 3 months thereafter 1

2. For patients receiving immunosuppressive therapy:

   • Initiate antiviral prophylaxis before or simultaneously with immunosuppressive therapy 1
   • Continue prophylaxis during immunosuppressive therapy and for at least 6-12 months after completion 1

Past HBV Infection (HBsAg-negative, anti-HBc-positive)

1. For patients receiving high-risk therapies (e.g., anti-CD20 monoclonal antibodies, stem-cell transplantation):

   • Initiate antiviral prophylaxis at the beginning of anticancer therapy 1
   • Continue for at least 12 months after completion of therapy 1
   • Monitor HBV DNA every 6 months during antiviral therapy 1
   • Alternative approach: Monitor HBsAg and HBV DNA every 3 months and start antivirals at earliest sign of reactivation 1

2. For patients receiving lower-risk anticancer therapies:

   • Monitor with HBV DNA and ALT testing every 1-3 months 1
   • Initiate antivirals if HBV reactivation occurs 1

Antiviral Medication Selection

• Preferred agents (high genetic barrier to resistance):

  • Entecavir 1, 5, 2
  • Tenofovir 1, 6, 2

• Not recommended:

  • Lamivudine (due to high resistance rates of 20-30%) 1

Special Considerations

• Hormonal therapy alone is unlikely to increase risk of HBV reactivation 1
• Renal function monitoring is essential with tenofovir use due to potential nephrotoxicity 6
• Cost-effectiveness: HBV screening is cost-effective even when prevalence is as low as 0.3% 1

Common Pitfalls to Avoid

1. Delaying anticancer therapy for HBV screening results - Anticancer therapy should not be delayed while awaiting screening test results 1

2. Using lamivudine for prophylaxis - High resistance rates make this a suboptimal choice; use entecavir or tenofovir instead 1

3. Discontinuing monitoring too early - Delayed HBV reactivation can occur years after cessation of anticancer therapy 1

4. Missing high-risk patients - Universal screening for cancer patients is more effective than risk-based screening, which may miss cases 1

5. Inadequate duration of prophylaxis - Continue antivirals for at least 12 months after completing anticancer therapy 1