Reactivation of hepatitis B infection among patients with cancer.

Abstract

9056 Background: Patients with active or occult hepatitis B virus (HBV) infection are at risk for reactivation after chemotherapy. Although studies of selected patients receiving chemotherapy have demonstrated reactivation rates of up to 50%, no large-scale study has ever been conducted in the US to understand the prevalence of HBV reactivation in a general cancer population. Methods: In this retrospective cohort study conducted at a comprehensive cancer center, we used institutional databases and chart reviews to investigate patients with newly diagnosed cancer who received chemotherapy between 1/2004 and 9/2007. Prevalence of HBV infection prior to chemotherapy was determined by testing HBsAg and anti-HBc. Reactivation of HBV infection was defined as: 1) ALT >100 IU/L or a 3-fold rise compared to baseline levels, and/or 2) detectable serum HBV DNA ≤ 6 months after initiation of chemotherapy. Using Chi-square tests of association, patients with reactivation were compared to those without reactivation in terms of demographic characteristics, cancer type, and chemotherapeutic agent. Results: Among 70,737 patients with cancer meeting our criteria, 10,729 received chemotherapy. Of these, 1787 (16.7%) were screened, and 151 patients were found to be positive for HBsAg and/or anti-HBc. Patients with HBV infection had a mean age of 53 years, 33.1% were women, and 47.7% were white. Overall, reactivation occurred in 73 patients (48.3%). Reactivation differed significantly by race (p=0.03): 26.0% of those with reactivation were Asian, compared to 9.0% without reactivation. There were no significant reactivation status associations with age, gender, or chemotherapeutic agent. Reactivation occurred in 39.1% (n=27) of solid tumor patients compared to 56.1% (n=46) of patients with hematologic malignancies (p=0.04). Conclusions: Reactivation occurred in nearly half of patients with HBV infection and cancer receiving chemotherapy; however, screening for HBV infection occurred in only a small percentage of patients. Determining the prevalence of this preventable cancer therapy complication is an essential first step in establishing an evidence-based screening policy for HBV infection in cancer patients.