Baseline hepatitis B DNA and end-of-treatment HBV surface antigen levels predicted virological relapse among patients with chronic HBV who ceased Baraclude or Viread therapy during chemotherapy, according to a recently published study.
“HBV reactivation can be spontaneous but is most commonly triggered by cancer chemotherapy, immune suppression, or alteration in immune function,” Ming-Te Kuo, MD, from the Chang Gung University College of Medicine, Taiwan, and colleagues wrote. “Multiple clinical guidelines and studies have shown that antiviral prophylaxis before the initiation of immunosuppressive treatment or chemotherapy can markedly decrease the risk of HBV reactivation.”
Between January 2010 and November 2015, Kuo and colleagues enrolled 122 patients with chronic HBV and cancer. At baseline, 78 patients had HBV DNA less than 2,000 IU/mL and 44 patients were active carriers with HBV DNA of 2,000 IU/mL or higher. Mean duration of antiviral prophylactic for chemotherapy was 62.2 weeks.
Median follow-up after patients ceased Baraclude (entecavir, Bristol-Myers Squibb) or Viread (tenofovir disoproxil fumarate, Gilead) was 106.5 weeks (range, 24-288 weeks). Fifty-two patients experienced virological relapse during follow-up.
Multivariate analysis showed that baseline HBV DNA of 2,000 IU/mL or higher (HR = 3.014; 95% CI, 1.662-5.465) and end-of-treatment HBsAg levels (HR = 1.657; 95% CI, 1.145-2.398) independently predicted virologic relapse.
Among patients with baseline HBV DNA less than 2,000 IU/mL, rituximab (HR = 5.416; 95% CI, 1.875-15.642) and end-of-treatment HBsAg levels (HR = 1.846; 95% CI, 1.154-2.953) independently predicted virological relapse.
The researchers found that an HBsAg level of 501.2 IU/mL was the best cut-off value to predict virological relapse within 3 years (AUROC = 0.773). HBsAg of 500 IU/mL was significant for those with a baseline HBV DNA less than 2,000 IU/mL, but not for those with higher HBV DNA.
Additionally, the researchers observed 18 patients who experienced clinical relapse. Multivariate analysis showed that old age, use of rituximab, Fibrosis-4 index higher than 3.25, combination of baseline alanine aminotransferase of 40 U/L and HBV DNA of 2,000 IU/mL or higher, and end-of-treatment HBsAg were independent risk factors for clinical relapse.
“The consolidation duration of antiviral prophylaxis for 6 to 12 months after cessation of the immunosuppressive treatment might be not enough for these patients. We suggested that the stopping rules of antiviral prophylaxis treatment in these cancer patients should be the same with the immunocompetent [chronic hepatitis B (CHB) patients],” the researchers wrote. “Close monitoring is needed for timely retreatment in cancer patients after the withdrawal of antiviral prophylaxis.” – by Talitha Bennett
Disclosure: The authors report no relevant financial disclosures.