Reactivation of hepatitis B virus (HBV) infection is common (~20-50%) during cancer chemotherapy. Baseline HBV replication status is an important risk factor for HBV reactivation. To date, data on the baseline HBV DNA level for chronic hepatitis B (CHB) patients prior to chemotherapy, particularly for non-hematological malignancies, are limited. A total of 105 consecutive CHB patients with solid tumors who received prophylactic antiviral therapy prior to chemotherapy from November, 2011 to December, 2014, were enrolled in this study. The patients' tumors included: Breast cancer (37.1%), lung cancer (18.1%), colon cancer (17.1%), head and neck cancer (10.5%), other gastrointestinal tract malignancies (8.6%), gynecological cancer (4.8%) and others (3.8%). The mean age of the enrolled patients was 55.2±1.1 years, 48 of the patients were male, 3 were hepatitis B e antigen-positive, and 26.7% had abnormal alanine aminotransferase (ALT) levels at baseline. The median HBV DNA level measured by quantitative polymerase chain reaction assay prior to chemotherapy was 3.30 log10 IU/ml and 49.5% of the enrolled patients had a baseline HBV DNA level >2,000 IU/ml. A wide range of HBV distribution was found: <20 IU/ml (15.2%), 20≤DNA<2,000 IU/ml (35.3%), 2,000≤DNA<20,000 IU/ml (26.6%), 20,000≤DNA<106 IU/ml (17.2%) and <106 IU/ml (5.7%). Age and baseline ALT level were not strongly associated with virological activity. The mean HBV DNA and the percentage of patients with HBV DNA >2,000 IU/ml were comparable between different cancer groups. Quantitative HBsAg level was a major determinant of baseline HBV DNA, and a significant correlation was noted between log10 hepatitis B surface antigen and log10 HBV DNA levels (γ=0.641, P<0.001). Our study demonstrated a wide distribution of baseline HBV DNA level among CHB patients diagnosed with non-hematological malignancies. Of note, approximately half of the patients (i.e., those with HBV DNA >2,000 IU/ml) had a higher risk of HBV reactivation if no appropriate antiviral prophylaxis was undertaken.
Keywords: chemotherapy; hepatitis B virus DNA level; hepatitis B virus reactivation; non-hematological malignancies; quantitative hepatitis B surface antigen level; quantitative polymerase chain reaction.