Bottom Line: Despite the steady increase of liver cancer incidence in the United States in recent decades, data from 2015 indicates that less than 13 percent of individuals born between 1945 and 1965 are estimated to have undergone screening for hepatitis C virus (HCV).
Journal in Which the Study was Published: Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.
Authors: Susan Vadaparampil, PhD, MPH, senior author, senior member and professor, Health Outcomes and Behavior Program, Moffitt Cancer Center, Tampa, Florida; Monica Kasting, PhD, lead author, postdoctoral fellow, Division of Population Science, Moffitt Cancer Center; Anna Giuliano, PhD, founding director of the Center for Infection Research in Cancer, Moffitt Cancer Center.
Background: "In the United States, approximately one in 30 baby boomers are chronically infected with HCV," said Vadaparampil. "Almost half of all cases of liver cancer in the United States are caused by HCV. Therefore, it is important to identify and treat people who have the virus in order to prevent cancer."
"Hepatitis C is an interesting virus because people who develop a chronic infection remain asymptomatic for decades and don't know they're infected," explained Kasting. "Most of the baby boomers who screen positive for HCV infection were infected over 30 years ago, before the virus was identified."
Because over 75 percent of HCV-positive individuals were born between 1945 and 1965, both the Centers for Disease Control and Prevention (CDC) and the U.S. Preventive Services Task Force (USPSTF) now recommend that baby boomers get screened for the virus. However, data from the 2013 National Health Interview Survey (NHIS) indicated that only 12 percent of baby boomers had been screened for HCV, Kasting explained. The researchers wanted to study if HCV screening rates had increased following the FDA approval of several well-tolerated and effective treatments for HCV infection.
How the Study Was Conducted: Using NHIS data from 2013-2015, Kasting and colleagues analyzed HCV screening prevalence among four different age cohorts (born before 1945, born 1945-1965, born 1966-1985, and born after 1985). Participants were asked if they had ever had a blood test for hepatitis C. As the researchers were interested in assessing HCV screening in the general population, they excluded certain populations who were more likely to be screened for the virus, resulting in a total sample size of 85,210 participants.
Results: After multivariable analysis, Kasting and colleagues found that females were screened less often than males in every age cohort. Additionally, among baby boomers and those born between 1966-1985, HCV screening rates were lower among Hispanics and non-Hispanic Blacks. "This is concerning because these groups have higher rates of HCV infection and higher rates of advanced liver disease," noted Kasting. "This may reflect a potential health disparity in access to screening, and therefore treatment, for a highly curable infection."
Among baby boomers, HCV screening rates ranged from 11.9 percent in 2013 to 12.8 percent in 2015. Regardless of the federal screening recommendations, less than 20 percent of baby boomers reported that the reason for their screening was due to their age.
Author's Comments: "Our most important finding is that the HCV screening rate isn't increasing in a meaningful way," said Giuliano. "Between 2013 and 2015, HCV screening only increased by 0.9 percent in the baby boomer population. Given rising rates of liver cancer and high HCV infection rates in this population, this is a critically important finding. It shows that we have substantial room for improvement and we need additional efforts to get this population screened and treated as a strategy to reduce rising rates of liver cancer in the United States."
Study Limitations: Limitations of the study include a reliance on self-reported data. "Another limitation is that this is secondary data and we didn't collect it ourselves," noted Kasting. "There are several questions we would have liked to ask about behavioral risk factors, such as drug use, that weren't utilized on this survey."
Funding & Disclosures: This study was supported by the Biostatistics Core and the H. Lee Moffitt Cancer Center & Research Institute. Kasting is supported by the National Cancer Institute (NCI) of the National Institutes of Health (NIH).
As a member of Merck Scientific Advisory Boards, Giuliano and her institution have received funds from Merck. An additional author on the study, David Nelson, MD, has received grant support from Abbvie, Gilead, and Merck. All other authors declare no conflicts of interest.