In a recent meta-analysis of patients with resolved hepatitis B who underwent chemotherapy for hematological malignancies, the presence of positive antibodies to HBV surface antigen, or anti-HBs, was correlated with a decreased risk for viral reactivation in the absence of antiviral prophylaxis.
“This finding supports the inclusion of anti-HBs in screening protocols prior to chemotherapy for hematological malignancy with antiviral prophylaxis for those who are anti-HBs-negative,” the researchers wrote.
The researchers searched for studies published from 1965 to Mar. 1, 2016, in the MEDLINE, Web of Science, Cochrane Register of Controlled Trials and Scopus databases using terms for HBV, cancer chemotherapy and virus reactivation and included 20 original reports in their analysis.
The reports comprised 11 prospective studies, eight retrospective studies and one randomized control trial that compared Baraclude (entecavir, Bristol-Myers Squibb) HBV prophylaxis prior to chemotherapy with entecavir therapy for HBV reactivation, totaling 1,713 patients with complete serology data. Only one study with 41 patients examined antiviral prophylaxis.
The risk for HBV reactivation was 7.2% (95% CI, 5-10) in 1,672 patients who did not receive antiviral prophylaxis during chemotherapy, 10% (95% CI, 5.8-16) in 800 patients who received Rituxan (rituximab; Genentech, Biogen) chemotherapy, and 4% (95% CI, 2.2-6.3) in 580 patients who received nonrituximab chemotherapy. Among 1,142 patients with lymphoma, the risk for reactivation was 8% (95% CI, 4-11).
For the 388 patients who were positive for antibodies to HBV core (anti-HBc) but negative for anti-HBs, the risk for reaction was 14% (95% CI, 9.4-19) compared with a 5% risk (95% CI, 3-7) in 1,284 patients with anti-HBs.
Compared with patients who were negative for anti-HBs, the presence of anti-HBs significantly reduced reactivation (OR = 0.21; 95% CI, 0.14-0.32). Specifically, in 800 who received rituximab-only chemotherapy, patients with anti-HBs had a greater reduced reactivation than those without (OR = 0.19; 95% CI, 0.11-0.31). The researchers also observed significantly reduced reactivation in patients with lymphoma who had anti-HBs (OR = 0.18; 95% CI, 0.11-0.28).
The researchers observed no heterogeneity among any of the studies.
“Given the risk of reactivation associated with rituximab-based therapy, we are in agreement with current guidelines that recommend HBV antiviral prophylaxis in patients receiving rituximab-based regimens regardless of anti-HBs status,” the researchers concluded. “However, the management of patients with resolved HBV infection receiving nonrituximab-based chemotherapy regimens remains uncertain.”
By Talitha Bennett