AASLD 2013: Studies Confirm Doctors Must Screen All Patients for Hepatitis B Before Starting Chemotherapy



— Christine M. Kukka, Project Manager, HBV Advocate

Chemotherapy drugs used to treat cancer and arthritis weaken the immune system and can cause a reactivation of HBV infection, even in people who have undetectable viral load and have cleared the hepatitis B surface antigen.

Unfortunately, many doctors still don’t screen cancer patients for current or resolved hepatitis B infections when prescribing rituximab chemotherapy for blood cancers. (This drug contains antibodies that suppress cancer cell reproduction.)

One study presented at AASLD found only 58% of patients were screened for HBsAg prior to chemotherapy and only 20% were screened for both HBsAg and hepatitis B core antibodies (showing a past, resolved infection) as recommended by international guidelines. This study found that life-threatening HBV reactivation occurred in patients whose only indication of past hepatitis B infection was the presence of core antibodies. (1)

Another impediment to proper treatment is that doctors don’t know which patients will experience an HBV reactivation when treated for blood cancers with rituximab chemotherapy. A Hong Kong study followed 210 patients treated with rituximab who had previously been infected with hepatitis B. They were all HBsAg-negative with undetectable HBV DNA.
 
About 27% of these patients had hepatitis B reactivation—evidenced by detectable viral load—most within six months of starting chemotherapy.

As soon as HBV DNA became detectable, the researchers treated them with the antiviral entecavir to suppress HBV. During the reactivation, HBsAg levels remained undetectable. It was an increase in the patient’s HBV DNA that was the first indication of hepatitis B reactivation. (2)
 
1. Control ID 1736332. Is isolated anti-HBc positivity a risk for reactivation in rituximab-treated patients? (Abstract #846)

2. Control ID 1736113. Interim analysis of hepatitis B reactivation in patients with prior HBV exposure undergoing rituximab-containing chemotherapy: a prospective study. (Abstract #34)

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