A substantial proportion of newly diagnosed cancer patients were unaware they were concurrently infected with hepatitis B virus (HBV), hepatitis C virus (HCV) or, less frequently, HIV, placing them at risk for serious adverse complications when treated with chemotherapy or other anti-cancer strategies, a SWOG Cancer Research Network study showed.
Out of a cohort of 3,051 newly diagnosed cancer patients, 6.5% (95% CI 5.6%-7.4%) had been previously infected with HBV, 87.3% (95% CI 81.8%-91.6%) of whom were diagnosed with HBV only at the time of study registration, Scot Ramsey, MD, PhD, of Fred Hutchinson Cancer Research Center in Seattle, and colleagues found.
Another 0.6% of patients (95% CI 0.4%-1.0%) had chronic HBV infection — 42.1% (95% CI 20.3%-66.5%) of whom had not been diagnosed prior to study entry.
As shown in the study online in JAMA Oncology, among a slightly smaller group of the same patients, 2.4% (95% CI 1.9%-3.0%) were HCV-positive — 31.0% (95% CI 20.5%-43.1%) of whom were unaware of their viral status on study entry.
HIV infection rates were lower, at only 1.1% (95% CI 0.8%-1.6%) in the overall cohort, but here again, 5.9% did not know their viral status at the time of study registration. The rates of HBV and HCV infection found in the study cohort were actually quite similar to rates found in the U.S. population as a whole, the researchers noted.
“The results of this study showed that a substantial proportion of patients with newly diagnosed cancer and concurrent HBV or HCV are unaware of their viral infection at the time of cancer diagnosis,” the researchers wrote. “Screening patients with cancer to identify HBV and HCV infection before starting treatment may be warranted to prevent viral reactivation and adverse clinical outcomes.”
Asked for his perspective, Harrys Torres, MD, of the University of Texas MD Anderson Cancer Center in Houston, agreed, noting that his institution had started screening all patients with hematologic malignancies for HBV and HCV about 10 years ago, because when started on chemotherapy, patients were at risk for complications related to reactivation of either virus which in some cases can be fatal.
A study led by his colleague Jessica Hwang, MD, also found that the majority of a large cohort of patients with solid and hematologic malignancies still required HBV testing if the goal is to achieve a false-negative rate of zero.
Similarly, another 2018 study by the group found that if HCV screening of newly diagnosed cancer patients is limited to the high-risk baby boomer birth cohort, many patients would be left with undiagnosed HCV infection, since many of the affected patients in the current study were not baby boomers, nor did they have risk factors for HCV. “For me, this important study is a prospective validation of our initial observations,” Torres told MedPage Today.
“Patients with HBV or HCV can present with any type of cancer — not just liver cancer but breast, prostate, and head and neck — and we have to identify these patients when they present because not only might they receive bone marrow transplantation or even rituximab, both of which can reactivate HBV and even HCV, but also we don’t yet know what any of the new cancer drugs are going to do in patients with HBV or HCV and these drugs could lead to other complications,” he suggested.
Lastly, the presence of either viral infection could prompt oncologists to err on the side of caution and offer patients a less effective treatment plan out of concern that concurrent HBV or HCV might lead to unwanted complications. This is particularly concerning, Torres noted, because HBV is treatable and HCV is potentially curable — and once the viral infections are treated, oncologists can proceed to treat patients as they optimally should be.
“Even if patients do have a viral infection, if we can eliminate that from the picture, patients can move on and receive the cancer treatment they need,” Torres emphasized.
For the current study, Ramsey and colleagues recruited patients from nine academic and nine community oncology institutions affiliated with SWOG and tested them for the presence of HBV, HCV, or HIV infection on study enrollment. About 60% of the patients were women; about 18% of the cohort were black, and another 18% were Hispanic.
“Previous HBV infection risk was highest in those who had sexual contact with HIV-positive persons, or who were born in high HBV-prevalence regions,” the team added.
HCV infection rates were also predictably highest among injection drug users, while the risk of HIV infection was highest in patients who had sexual contact with other HIV-positive persons. However, as the authors noted, many patients identified as having HBV, HCV, and HIV infection in the current study had no known risk factors.
This underscores, as Torres said he himself has found, the futility of using a risk-based screening strategy which would miss substantial proportions of infected patients who, unaware of their viral status, could pose a transmission risk to family and healthcare workers alike.
“As a cancer patient, or physician, I would want to know the results of a hepatitis screening test,” Ramsey said in a statement. “The presence of a potentially life-threatening infection could guide care in very important ways. In medicine, more knowledge is always better.”
Ramsey reported having no financial conflicts of interest to declare.
Torres reported financial relationships with Gilead Sciences, Merck, and Dynavax.