Singapore has a relative higher prevalence of Hepatitis B carriage at 3.6%. The risk of Hepatitis B virus (HBV) flare which is increased in patients receiving anthracycline chemotherapy has clinical relevance due to associated morbidity. Guidelines recommend a risk-adaptive screening strategy. This study aims to analyze the practice of HBV screening, and incidence of flare among non-metastatic breast cancer patients treated with anthracyclines.
This is a retrospective review of all non-metastatic breast cancer in the Joint Breast Cancer Registry (JBCR) treated with (neo)adjuvant doxorubicin based therapy between August 2015 and December 2016, across 3 tertiary institutions in Singapore. We examined data collected prior to chemotherapy initiation regarding HBV status, including liver function (LFT), HBV surface antigen (HBsAg), antibody to HBV (Anti HBs), HBV core total antibody (Anti HBc) and HBV deoxyribonucleic levels (HBV DNA). We reviewed the course of HBV carriers (HBsAg positive) or prior HBV exposed patients (Anti HBc total positive and HBsAg negative) during chemotherapy for any HBV flare (abrupt rise of alanine aminotransferase levels to more than 5 times upper limit of normal in a carrier).
492 early breast cancer patients were examined. 484 (98.3%) had HBsAg, 159 (32.3%) had Anti HBs and 16 (3.3%) had Anti HBc performed prior to starting chemotherapy. There were 12 HBV carriers and 4 with previous HBV exposure. Among the 12 HBV carriers, 4 were on antivirals prior to the diagnosis of breast cancer, and 8 were started on antivirals following diagnosis. 1 patient received doxorubicin prior to starting antivirals and developed HBV flare after the first cycle. The patient was started on entecavir, with improvement in HBV DNA levels and LFT, and chemotherapy was resumed. Remaining carriers did not develop flares. The patients with prior HBV exposure were monitored with serial LFT, and did not develop transaminitis.
Patients are almost universally screened for HBV with HBsAg prior to anthracyclines. Our data was consistent with local carriage rate. The incidence of flare is low with appropriate antiviral prophylaxis. HBsAg alone may be sufficient for screening.
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All authors have declared no conflicts of interest.