According to the results of a study published in the Journal of the American Medical Association, individuals who are infected with the hepatitis C virus are 20–30% more likely than non-infected individuals to develop non-Hodgkin’s lymphoma.
Infection with the hepatitis C virus (HCV) has been linked with chronic hepatitis, cirrhosis of the liver, and liver cancer. It is most commonly acquired through contact with infected blood. The infection can be spread by injection drug use, and has also been reported among individuals who received blood transfusions or organ transplants prior to widespread donor screening. An estimated 1.6% of the U.S. population is infected with HCV.
Non-Hodgkin’s lymphoma (NHL) is a form of cancer that begins in the cells of the lymph system, which includes the spleen, thymus, tonsils, bone marrow, lymph nodes, and circulating immune cells. Lymphocytes are the main cells in the lymph system and exist in two forms: B- and T-cells. Each of these cells serves a specific function in aiding the body fight infection.
In NHL an excessive amount of atypical (cancerous) lymphocytes accumulates in the lymph system. These lymphocytes can crowd and suppress the formation and function of other immune and blood cells.
Because there is some evidence that HCV may increase the proliferation of cells in the lymph system, researchers conducted a study to evaluate the risk of NHL and certain other types of cancer in individuals with and without HCV. In addition to NHL, the researchers collected information about Hodgkin’s lymphoma, leukemia, multiple myeloma, and thyroid cancer. The decision to include thyroid cancer was based on previous reports of a possible link with HCV.
The study was conducted among a large sample of U.S. veterans. The study included 146,394 individuals with HCV and 572,293 individuals without HCV. Individuals infected with human immunodeficiency virus (HIV) were excluded. Most of the study participants were men, and their average age was 52 years.
- HCV-infected individuals were 20–30% more likely to develop NHL than non-infected individuals.
- The risk of a rare, slow-growing type of NHL known as Waldenström macroglobulinemia was almost three-times higher in HCV-infected individuals than in non-infected individuals.
- HCV-infected individuals did not appear to have an increased risk of developing Hodgkin’s lymphoma, leukemia, multiple myeloma, or thyroid cancer.
The researchers conclude that infection with the hepatitis C virus appears to increase the risk of non-Hodgkin’s lymphoma.
 Armstrong GL, Wasley A, Simard EP, McQuillan GM, Kuhnert WL, Alter MJ. The prevalence of hepatitis C virus infection in the United States, 1999 through 2002. Annals of Internal Medicine. 2006;144:705-714.