Hepatitis C Infection Ups Lymphoma Risk

TUESDAY, May 8 (HealthDay News) -- People with the liver disease hepatitis C face a higher risk of developing lymphoma, a cancer of the immune system, new research suggests.

Overall, the risk is almost 30 percent higher, but for a certain type of lymphoma called Waldenstrom's macroglobulinemia, the risk is almost 300 percent higher, according to the study.

"If I had hepatitis C, this would be one more piece of evidence that might make me consider treatment, though hepatitis C treatment can be difficult and is often unsuccessful," said the study's lead author, Dr. Thomas Giordano, an assistant professor of medicine at Baylor College of Medicine in Houston.

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"On the other hand," he added, "the risk of these cancers is so small, I wouldn't panic if wasn't getting treatment either. The overall risk is low."

More than 4 million Americans have hepatitis C, and about 26,000 new cases are diagnosed each year, according to the U.S. Centers for Disease Control and Prevention. Lymphomas are cancers that originate in the lymphatic system, a part of the body's immune system. The two most common forms of lymphoma are Hodgkin's and non-Hodgkin's lymphoma. About 8,000 Americans develop Hodgkin's lymphoma and more than 56,000 develop non-Hodgkin's lymphoma each year, according to the Leukemia and Lymphoma Society.

"At least five agents -- four viruses and one bacterium -- are associated with an increased risk of lymphoma, said Dr. Marshall Lichtman, executive vice president for research and medical programs at the Leukemia and Lymphoma Society.

But, Lichtman said he couldn't speculate as to why hepatitis C might increase the risk of lymphoma.

Giordano suspects that the chronic stimulation of the immune system caused by hepatitis C might be contributing to the development of certain lymphomas.

For the new study, Giordano and his colleagues reviewed data from the Veterans Administration. First, they found almost 150,000 veterans with a diagnosis of hepatitis C, and then they matched by age and sex four healthy veterans for each person infected with hepatitis C. Nearly all of the veterans included in the study were male, and the average age was 52.