Hepatitis B screening remains important prior to anticancer therapy
Although a risk assessment tool can identify patients with cancer who are at risk for hepatitis B virus (HBV) reactivation from anticancer therapy, most patients will still require HBV testing, according to study results.
“This study is the first to provide strong data to help determine optimal HBV screening strategies for patients with cancer,” Jessica P. Hwang, MD, MPH, associate professor in the department of general internal medicine at The University of Texas MD Anderson Cancer Center, told HemOnc Today. “Our findings may have implications for HBV screening for patients with cancer or other conditions requiring immunosuppressive therapies to prevent HBV reactivation or even the broad public health community to prevent HBV-related adverse outcomes, including hepatocellular carcinoma.”
Despite risk for HBV reactivation after immunosuppressive therapy, most patients with cancer are not screened for HBV infection prior to undergoing therapy.
“HBV screening before starting immunosuppressive treatment is an important part of providing safe cancer care,” Hwang said.
How to accurately identify which patients are at risk has remained a challenge.
“There are many well-established risk factors for HBV infection based on demographics, sexual and lifestyle behaviors, and medical conditions. However, risk factors are seldom assessed, in part, due to time constraints,” Hwang said.
Further, no validated HBV risk tools exist to assist oncology teams in screening patients prior to initiation of immunosuppressive therapies to prevent HBV reactivation and associated adverse outcomes. Therefore, HBV testing has remained suboptimal among patients with cancer.
Investigators identified 2,124 patients (mean age, 54 years) who received anticancer treatment at The University of Texas MD Anderson Cancer Center between July 2013 and December 2014. More than half of the patients (54%) were women and most were non-Hispanic white (77%); 12% were born outside of the United States. Twenty-percent had a hematologic malignancy and 80% had a solid tumor.
All patients underwent hepatitis B surface antigen (HBsAg) hepatitis B core antibody (anti-HBc), and hepatitis B surface antibody testing (anti-HBs), and they completed the CDC hepatitis risk survey.
The survey included 18 questions about age and gender, place of birth, blood transfusion or organ transplant prior to 1992 or clotting factor disorder, history of chronic liver disease, HIV or AIDS, diabetes, sexual behaviors, injection drug use, household exposure to HBV and other factors. Researchers also added a question on race and ethnicity to create a modified 19-question version.
The cohort included 135 patients with either past HBV (n = 128) or chronic HBV (n = 7). Among patients with past infection, 77% had resolved infection determined by positive anti-HBc and anti-HBs tests; 21% had occult HBV determined by positive anti-HBc and negative anti-HBs testing; and three had indeterminate anti-HBs results with an antibody level below the threshold of quantification.
Factors that significantly predicted positive anti-HBc and anti-HBs tests in an initial multivariable model included men who had sex with men, black or Asian race, patient or parent birthplace outside the U.S., exposure to HBV in the household, age 50 years or older, and history of injection drug use.
The area under the receiver operating characteristic curve on the basis of these predictors —which researchers called Model C — was 0.79 (95% CI, 0.73-0.82).
The false-negative rate for the 19-question modified CDC survey was 0%, which indicated patients with chronic or past HBV would have been identified if patients with at least one positive answer to any of the questions underwent serological testing.
The false-negative for the 18-question CDC hepatitis risk assessment was 3%, meaning four patients with HBV would not have been identified in this cohort.
The false-negative rate of the seven-question model was 1.5% and would have led to missing two patients with past HBV infection.
The proportion of patients who answered “yes” to at least one of any of these surveys was at least 90%, indicating approximately 90% of patients would require HBV serologic testing.
“Therefore, our study results indicate universal HBV screening is more efficient than risk-based screening,” Hwang said.
In lieu of universal testing, however, the abbreviated survey by Hwang and colleagues can be used to screen patients with intermediate or low risk for HBV reactivation, according to Andrew S. Artz, MD, associate professor and clinical director of hematopoietic cellular therapy at The University of Chicago, and Sonali Paul, MD, MS, assistant professor of medicine at The University of Chicago.
“Clinicians and institutions ultimately need to determine a standardized approach for non-highly immunosuppressive regimens that incorporate patient characteristics that are related to HBV infection risks and the reactivation risk associated with cancer therapies,” Artz and Paul wrote in a related editorial. – by Melinda Stevens
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Jessica P. Hwang, MD, MPH, can be reached at firstname.lastname@example.org.
Disclosures: Hwang reports research funding from Gilead Sciences and Merck. Please see the study for a list of all other authors’ relevant financial disclosures. Artz reports research funding from Militenyi Biotec and Neovii Biotech. Paul reports no relevant financial disclosures.