Screening for Chronic Hepatitis B in Patients Undergoing Chemotherapy for Lymphoma or Colon Cancer

Abstract

Purpose: Approximately 350 to 400 million people are hepatitis B surface antigen (HBsAg) carriers. HBsAg carriers who receive cytotoxic or immunosuppressive therapy are at significant risk of hepatitis B (HBV) reactivation. Spontaneous reactivation may occur in up to 22% of HBV-infected patients with previously negative HBeAg status. Cytotoxic therapy has been shown in prospective studies to confer a threefold greater risk of viral reactivation. Patients undergoing chemotherapy are often not screened for HBV infection, and prophylactic antiviral therapy is markedly underused. The use of steroids with chemotherapy for patients with hematologic malignancies poses the greatest risk of reactivation, up to 67%. For solid tumors such as breast cancer, a slightly lower risk of 40% exists. There does not appear to be extensive data reporting the reactivation risk of HBV for chemotherapy in colon cancer. Methods: This was a retrospective chart review of patients at Scott & White Healthcare Hospital who have undergone chemotherapy for lymphoma or colon cancer. For each patient, liver function tests (LFTs) were trended for the duration of the chemotherapy. We reviewed the charts to determine if patients were screened for HBV prior to chemotherapy induction. If patients were HbsAg-positive, we further reviewed the chart for initiation of chemoprophylaxis. HBV screening rate and 95% Confidence Interval (CI) were estimated for entire cohort, both normal and abnormal LFT groups. HBV screening rates between the 2 groups were compared using Chi-square test. SAS version 9.2 (SAS Institute INC, Cary, NC) was used for statistical analysis. Results: Approximately 800 lymphoma and 500 colon cancer cases were found and preliminary analysis was performed on 242 patients. See table 1 for descriptive statistics. Two patients were excluded as they did not have any LFTs. Of the 240 patients, 110 had normal LFTs and 130 abnormal LFTs. See table 2 for comparison of HBV screening results between the normal and abnormal LFT groups. Screening rates between the two groups were significantly different (p-value=0.0244). A total of 17 patients received HBV screening (screening rate 7.02% with 95% CI of (4.15-11.01%). One of the excluded patients received screening.Table 1Table 2Conclusion: As our preliminary analysis has shown, screening rates in our study were low. Despite guidelines, chemoprophylaxis of HbsAg carriers is low prior to cancer chemotherapy. Our data analysis is ongoing and will be complete at the time of publication.