Assessment of hepatitis B virus relapse in cancer patients receiving chemotherapy with prophylactic nucleos(t)ide analogues: Implications for overall mortality

Background and Aims We aimed to explore the risk factors associated with virological and clinical relapse, as well as their impact on overall mortality, in hepatitis B virus (HBV)‐infected patients receiving nucleos(t)ide analogues (NUCs) therapy prior to chemotherapy initiation. Methods From 2010 to 2020, we conducted a prospective cohort study involving patients with HBV infection undergoing cytotoxic chemotherapy. We utilized the Kaplan–Meier method and Cox proportional hazard regression models to assess risk factors. Results We observed that TDF or TAF (HR: 2.16, 95% CI 1.06–4.41; p = .034), anthracycline (HR: 1.73, 95% CI 1.10–2.73; p = .018), baseline HBV DNA (HR: 1.55, 95% CI 1.33–1.81; p 100 IU/mL (HR: 7.81, 95% CI 1.94–31.51; p = .004) were associated with increased risk of virological relapse. Additionally, TDF or TAF (HR: 4.91, 95% CI 1.45–16.64; p = .011), baseline HBV DNA (HR: 1.48, 95% CI 1.10–1.99; p = .009) and end‐of‐treatment HBsAg titre >100 IU/mL (HR: 6.09, 95% CI .95–38.87; p = .056) were associated with increased risk of clinical relapse. Furthermore, we found that virological relapse (HR: 3.32, 95% CI 1.33–8.32; p = .010) and clinical relapse (HR: 3.59, 95% CI 1.47–8.80; p = .005) significantly correlated with all‐cause mortality in HBV patients receiving cytotoxic chemotherapy with prophylactic NUCs therapy. Conclusions The risk of virological and clinical relapse was linked to baseline HBV DNA, end‐of‐treatment HBsAg levels and TDF or TAF for prophylaxis; additionally, experiencing relapse heightens the risk of all‐cause mortality. Further research is warranted to explore potential strategies for preventing virological and clinical relapse in high‐risk patients.