Prevalence of vaccine-induced immunity to hepatitis B in cancer patients: A 13-year analysis in a quaternary oncological center.

BACKGROUND

Hepatitis B virus reactivation may occur in cancer patients, leading to liver damage and early discontinuation of treatment. To evaluate vaccine-induced immunity to hepatitis B, this study investigated the prevalence of anti-HBs antibodies from patients with solid tumors or hematological malignancies.

METHODS

All cancer patients who underwent serological testing for anti-HBs from 2011 to 2023 and had negative anti-HBc results at the Instituto do Cancer do Estado de Sao Paulo, Brazil, were included. The prevalence of vaccine-induced immunity to hepatitis B during those years was assessed by using linear regression. Characteristics associated with presence of anti-HBs and anti-HBs titers (strongly positive: ≥ 100 IU/L; weakly positive: 10-99 IU/L) were evaluated by using multivariable logistic regression.

RESULTS

A total of 23,854 patients were evaluated, 17,249 with solid tumors and 5114 with hematological malignancies. The prevalence of vaccine-induced immunity to hepatitis B was 22.1 %, with a significant linear increase over time (p < 0.001). The presence of vaccine-induced immunity to hepatitis B was associated with younger age (OR=7.23, 95 % CI: 6.55-7.98), female sex (OR=1.25, 95 % CI: 1.15-1.36), non-white patients (OR=1.13, 95 % CI: 1.04-1.22), and patients with hematological malignancies (OR=1.16, 95 %CI: 1.07-1.27). Additionally, the variables younger age (OR=1.64, 95 % CI: 1.39-1.94) and female sex (OR=1.39, 95 % CI: 1.20-1.60) were associated with strongly protective anti-HBs titers (≥ 100 IU/L).

CONCLUSIONS

This finding indicates that approximately one-quarter of a large population with cancer was protected against HBV infection through serological evidence of anti-HBs. Preventive strategies are needed for cancer patients, who may benefit from hepatitis B vaccination.