# Hepatitis B blood tests before anyone starts systemic cancer treatment, with antiviral tablets for those who need them

Source: https://onco.cc/ideas/idea-upgrade-hepatitis-b-testing-before-systemic-treatment/  
OnCo record `idea-upgrade-hepatitis-b-testing-before-systemic-treatment` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Hepatitis B can lie quiet for decades and flare when cancer treatment weakens the immune system, sometimes fatally. An American Society of Clinical Oncology opinion says everyone starting systemic cancer treatment should be tested first, and antiviral tablets prevent most flares. Across 29 studies, 57 per cent of patients were tested before chemotherapy.

## Summary

The recommendation. The 2020 ASCO provisional clinical opinion states that "all patients anticipating systemic anticancer therapy should be tested for HBV by 3 tests" (hepatitis B surface antigen, core antibody and surface antibody), "but anticancer therapy should not be delayed". People with chronic infection receiving any systemic anticancer therapy should receive antiviral prophylaxis during and for at least 12 months after treatment; people with past infection receiving high-risk treatment such as anti-CD20 antibodies or stem cell transplantation should receive prophylaxis or, where follow-up can be relied on, careful monitoring.

Why it works. A 2008 systematic review of 14 studies (two randomised) in surface-antigen-positive patients receiving chemotherapy found relative risks for reactivation and hepatitis between 0.00 and 0.21 with preventive lamivudine; hepatic failure occurred in none of 108 patients given it against 21 of 162 controls, and deaths attributed to hepatitis B in 4 of 208 against 27 of 394. A randomised trial in 121 surface-antigen-positive patients with diffuse large B-cell lymphoma receiving R-CHOP then showed entecavir outperformed lamivudine: hepatitis 0 against 13.3 per cent, reactivation 6.6 against 30 per cent, chemotherapy disrupted 1.6 against 18.3 per cent.

The measured gap. A 2024 meta-analysis of 29 studies found a pooled screening rate before chemotherapy of 57 per cent, rising from 37 per cent in 2006 to 2010 to 69 per cent in 2016 to 2020. Rates were 89 per cent in high-prevalence countries and 49 per cent in low-prevalence ones, 65 per cent in blood cancers against 37 per cent in solid tumours, and 68 per cent with rituximab-containing regimens against 45 per cent without.

## Fields

- Kind: Idea
- Last checked: 2026-10-20
- Tags: protocol-upgrade; upgrade:proven-unevenly-used; evidence:strong
- Hypothesis: Making the three hepatitis B tests a hard stop in the first systemic therapy order set, with an automatic referral pathway for positive results, raises pre-treatment testing above 95 per cent in solid-tumour as well as blood cancer services and eliminates avoidable reactivation.
- Rationale: The test is cheap, the treatment is a daily tablet, and the harm it prevents can be fatal and interrupts the cancer treatment itself. The gap is largest exactly where clinicians assume the virus is rare, which is where a default does the most good.
- Proposed test: Implementation in a solid-tumour chemotherapy service with pre-treatment testing rate as the primary measure and reactivation events, prophylaxis given to those eligible, and any delay to the start of cancer treatment as secondary measures, compared with the service's own baseline.
- Maturity: being-tested-at-scale
- Actor: clinic

## Sources

- Hwang et al., Hepatitis B Virus Screening and Management for Patients With Cancer Prior to Therapy: ASCO Provisional Clinical Opinion Update (J Clin Oncol 2020): https://doi.org/10.1200/JCO.20.01757
- Maung et al., Screening for viral hepatitis B infection in cancer patients before receiving chemotherapy: a systematic review and meta-analysis (Asia Pac J Clin Oncol 2024): https://doi.org/10.1111/ajco.14055
- Loomba et al., Systematic review: the effect of preventive lamivudine on hepatitis B reactivation during chemotherapy (Ann Intern Med 2008): https://doi.org/10.7326/0003-4819-148-7-200804010-00008
- Huang et al., Entecavir vs lamivudine for prevention of hepatitis B virus reactivation in diffuse large B-cell lymphoma receiving R-CHOP: a randomized clinical trial (JAMA 2014): https://doi.org/10.1001/jama.2014.15704

## Connected records

- fronts: [Chemotherapy](https://onco.cc/fronts/chemotherapy/), [Supportive Care & Survivorship](https://onco.cc/fronts/supportive-care/)
- drugs: [Rituximab](https://onco.cc/drugs/rituximab/)
- terms: [Hepatitis B and C as cancer causes](https://onco.cc/terms/hbv-hcv/), [Hepatitis B reactivation before rituximab and other anti-CD20 antibodies](https://onco.cc/terms/lymphoma-tx-hepatitis-b-reactivation/)
- bottlenecks: [Fragmented care and guideline gaps](https://onco.cc/bottlenecks/b-care-fragmentation/), [Toxicity and quality of life are undervalued](https://onco.cc/bottlenecks/b-toxicity-qol/)

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