• How Many Patients are Screened for HBV Infection Before Chemotherapy?

How Many Patients are Screened for HBV Infection Before Chemotherapy?

Only a small percentage of patients receiving chemotherapy are screened for hepatitis B virus (HBV) infection, although the proportion of patients screened has increased slightly over the past decade, researchers report in the May issue of Clinical Gastroenterology and Hepatology. Strategies are needed to ensure that patients receiving chemotherapy are protected from the consequences of undiagnosed HBV infection.

Immunosuppressive agents, such as biologics and cytotoxic chemotherapies, can reactivate infection with viruses such as HBV. This can cause serious, sometimes fatal, complications, and also limits the ability of clinicians to treat the patient’s cancer or other disease. HBV reactivation can be prevented with preemptive antiviral therapy—a better option than later treatment of a hepatitis flare.

The Centers for Disease Control and Prevention and the American Association for the Study of Liver Diseases recommend screening all patients for HBV infection before immunosuppressive therapy. However, not all government authorities or professional societies support this recommendation.

To determine how many patients are screened for HBV infection before treatment, Chung-Il Wi et al collected data from 8005 patients receiving chemotherapy at the Mayo Clinic in Rochester, Minnesota, from January 1, 2006, through September 30, 2011.

They found that 1279 of the patients (16%) were screened for HBV infection before chemotherapy, including 668 of 1805 patients with hematologic malignancies (37%).

The proportion of patients screened for HBV increased significantly with time, from 14.3% in 2006 to 2008 to 17.7% in 2009 to 2011 (see graph).

Proportion of chemotherapy recipients screened for HBV, from 2006 through 2011.

Proportion of chemotherapy recipients screened for HBV, from 2006 through 2011.

However, this increase was attributed mostly to an increase in the proportion of patients with hematologic malignancies, from 32.7% in 2006 to 2008 to 40.6% in 2009 to 2011. Only 1.1% of Asian American patients were screened for HBV.

Of 13 patients who tested positive for HBV, 5 did not receive prophylactic antiviral therapy—HBV was reactivated in 2 of these patients. Alternatively, HBV was not reactivated in any of the 8 patients who received an antiviral agent before chemotherapy.

Why the low level of screening for HBV in chemotherapy patients? Wi et al explain that there are differences between guideline recommendations from liver vs oncology societies.

The American Society of Clinical Oncology makes HBV screening optional. They say that physicians should consider the degree of immunosuppression and the risk of individual patients before deciding on HBV screening. Most oncologists screen select subgroups based on risk factors such as ethnicity or levels of liver enzymes. Wi et al identified age, abnormal levels of liver enzymes, and hematologic malignancies as markers for HBV screening.

Opponents of universal HBV screening state that there is insufficient evidence for its net risks vs benefits or cost effectiveness.

Wi et al explain that gastroenterologists and hepatologists often see patients receiving chemotherapy who have aggressive reactivation of a previously undiagnosed HBV infection. In contrast, oncologists, who prescribe chemotherapy to a large number of patients, do not have many patients with HBV reactivation.

There is consensus that Asian Americans should be tested for HBV, even in the absence of chemotherapy. However, this group does not appear to receive higher rates of screening than other populations.

Wi et al conclude that it is important to convince oncologists of the need to screen for HBV in patients undergoing chemotherapy—especially patients with hematologic malignancies, Asian or Pacific Islanders, and patients with abnormal levels of liver enzymes.

In an editorial that accompanies the article, Bruno Roche and Didier Samuel state that oncologists, rheumatologists, and gastroenterologists who treat patients with immunosuppressive therapy should not underestimate the potential severity of HBV reactivation or have too much confidence in the ability of antiviral agents to save patients with life-threatening HBV reactivation.

Roche and Samuel add that it is important to increase the awareness among physicians of the markers of HBV, including hepatitis B surface antigen (HBsAg) hepatitis B core antibody (anti-HBc). They recommend treatment with drugs that have high barriers to resistance, such as entecavir or tenofovir.

This article has continuing education activity.

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