Last Updated: 2003-04-07 13:12:25 -0400 (Reuters Health)
 
NEW YORK (Reuters Health) - A new study provides additional evidence that the liver infection hepatitis C may contribute to a form of the cancer lymphoma.
 
It is too soon to know whether the association between the hepatitis C virus (HCV) and non-Hodgkin's lymphoma will affect the treatment of the cancer, study author Dr. Eric A. Engels told Reuters Health.
 
"Our study was not designed to tell patients how they might be treated," said Engels, who is at the National Cancer Institute in Rockville, Maryland. "One thing I can say is that in the United States it is likely that HCV infection is responsible for only a small portion of lymphomas."
 
The results of at least one study suggest that treating HCV infection can improve cancer prognosis. In a study published last year, people who had HCV infection and who had a rare type of lymphoma called splenic marginal zone lymphoma went into remission after they were treated for HCV.
 
"For these people, treating the HCV can make a difference," Engels said. "Having said that, our study does not really provide any direct evidence regarding the role of treating HCV in lymphoma patients."
 
Past studies examining a possible connection between the hepatitis C virus and non-Hodgkin's lymphoma have produced "a range of results," according to Engels.
 
Some have found what appeared to be a strong association between the liver infection and the cancer, while others have failed to detect any connection. To some extent, the differences may be due to the design of the study or where the study was based, Engels said.
 
In the new study, Engels and his colleagues examined how often people with non-Hodgkin's lymphoma in four regions of the U.S. were also infected with HCV.
 
"We did find an association between HCV and NHL," Engels said. "It was not as strong as some of the other studies, but I think its quite representative."
 
In the study of about 1,500 people, people with non-Hodgkin's lymphoma were about twice as likely to be infected with HCV as healthy individuals. HCV was present in 3.9 percent of people with non-Hodgkin's lymphoma compared with 2.1 percent of healthy individuals.
 
Engels said he and his colleagues were unable to identify whether specific subtypes of non-Hodgkin's lymphoma were associated with HCV infection. Additional studies are needed, he added, to confirm the current findings, identify which varieties of non-Hodgkin's lymphoma are related to HCV and to uncover the mechanisms responsible for the association.
 
Engels was scheduled to present the findings during the American Association for Cancer Research's 94th Annual Meeting in Toronto this past Sunday, but the event was canceled due to growing concern about cases of severe acute respirator syndrome (SARS) in the city.
 
Non-Hodgkin's lymphoma refers to several types of cancer that start in the lymphatic system but often spread throughout the body.
 
Nearly 4 million Americans have hepatitis C, making it one of the most common chronic viral infections in the U.S. Chronic inflammation of the liver develops in many patients, and about 20% of people with hepatitis C will develop cirrhosis, a severe and sometimes fatal scarring of the liver. Cirrhosis increases the risk of liver cancer.