Hepatitis C infection is associated with a 20 to 30 percent increased risk of developing non-Hodgkin lymphoma (malignancy involving lymphatic tissue) and a three-fold increase in the risk of developing the low-grade lymphoma Waldenström macroglobulinemia, say researchers in an article in the May 9 issue of The Journal of the American Medical Association.
A research team led by Thomas P. Giordano, M.D., M.P.H., of Baylor College of Medicine and the Michael E. DeBakey Veterans Affairs Medical Center, Houston, conducted a retrospective cohort study to test the hypothesis that hepatitis C virus (HCV) infection is associated with increased risk of developing malignancies of the blood and blood-forming tissues, related disorders and thyroid cancer.
The study involved patients from U.S. Veterans Affairs health care facilities from 1997 through 2004. It included 146,394 patients who were infected with HCV and 572,293 patients who were not infected with HCV. The research team examined the risks of hematopoietic malignancies, related lymphoproliferative precursor diseases and thyroid cancer.
They found 1,359 patients with non-Hodgkin lymphoma, 165 patients with Waldenström macroglobulinemia, 551 patients with cryoglobulinemia and 320 patients thyroid cancer. They also found that HCV infection was associated with an increased risk of developing nonmalignant plasma cell disorders.
The study found no significantly increased risk for other hematological malignancies. The risk for thyroid cancer was not increased.
"Although the clinical significance of these findings is unknown, it is possible that screening of individuals infected with HCV could identify early stage lymphoproliferative conditions suitable for early intervention strategies, including chemoprevention trials on pre-malignant disease. Future epidemiologic and pathophysiological studies are needed to further explore the relationship between HCV and NHL," the authors conclude.
