Systematic review: the effect of preventive lamivudine on hepatitis B reactivation during chemotherapy

Background: Lamivudine is increasingly being used to prevent hepatitis B reactivation in patients with cancer who test positive for hepatitis B surface antigen (HBsAg) and are undergoing chemotherapy. Purpose: To determine whether preventive lamivudine reduces chemotherapy-induced hepatitis B virus (HBV)--related morbidity and mortality in patients with cancer who test positive for HBsAg. Data Sources: MEDLINE, Ovid MEDLINE, TOXNET, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were searched in all languages until June 2007. Study Selection: Clinical trials and cohort studies that reported the efficacy of preventive lamivudine versus control on HBV reactivation in patients who tested positive for HBsAg and were receiving chemotherapy were included. Additional requirements included minimum sample size (>5 participants per treatment group) and reported HBV-related morbidity and mortality data. Data Extraction: Two investigators independently did literature searches and data extraction, and 2 other investigators independently confirmed study eligibility and data retrieval. Data Synthesis: Fourteen studies (2 randomized, controlled trials; 8 prospective cohort studies; and 4 retrospective cohort studies) met the predefined criteria for analysis. There were 275 patients in the preventive lamivudine group and 475 control participants for the primary end point of HBV reactivation. With preventive lamivudine, the relative risk for both HBV reactivation and HBV-related hepatitis ranged from 0.00 to 0.21. None of the patients in the preventive lamivudine group developed HBV-related hepatic failure (0 of 108 patients vs. 21 of 162 patients), and only 4 deaths were attributable to HBV (4 of 208 patients vs. 27 of 394 patients) in the preventive lamivucline group. Lamivudine was well tolerated, and no adverse effects were noted. Limitations: The studies included in the meta-analysis did not consistently report all of the outcomes of interest. Sample sizes were small and only 2 studies had a randomized, controlled design. Conclusion: Preventive therapy with lamivudine for patients who test positive for HBsAg and are undergoing chemotherapy may reduce the risk for HBV reactivation and HBV-associated morbidity and mortality.