Researchers in the U.S. have found that an infection with the hepatitis C virus increases the risk of a person developing non-Hodgkin's lymphoma.
Hepatitis C has a rather bad track record as it has already been linked to an increased risk of liver cancer and cirrhosis.
The hepatitis C virus (HCV) is estimated to affect about 1.6 percent of the U.S. population but it is more common among U.S. military veterans who use the Veterans Affairs (VA) medical system, and approximately five percent of veterans are infected with HCV.
In their study the researchers tracked 146,394 U.S. military veterans infected with the virus and 572,293 veterans who were not, between 1997 to 2004; all but 3 percent were men, most were white, and their average age was 52.
They found that HCV infection boosted the risk for non-Hodgkin's lymphoma by 20 percent to 30 percent.
Non-Hodgkin's lymphoma is cancer that starts in the lymphoid tissue that makes up the lymph nodes, spleen and other organs of the immune system; tumors develop from white blood cells and the cancer is more common in men than women.
The researchers also found that HCV infection raised by 300 percent the risk for a rare slow growing form of non-Hodgkin's lymphoma called Waldenstrom's macroglobulinemia.
The risk for cryoglobulinemia where abnormal levels of certain antibodies appear in the blood, also rose.
The researchers found there were 1,359 cases of non-Hodgkin lymphoma, 165 cases of Waldenstrpm macroglobulinemia, 551 cases of cryoglobulinemia and 320 cases of thyroid cancer.