Hepatitis C link to Myeloma

People infected with the hepatitis C virus (HCV) have a higher risk of developing non-Hodgkin's lymphoma and multiple myeloma, according to a recent study of the Swedish population.

Previous studies have shown that people with HCV have a higher risk of developing cirrhosis and liver cancer. In Sweden, a cluster of four cases of non-Hodgkin's lymphoma in 554 HCV patients raised the question of an association between those two diseases and other related cancers.

To evaluate this possibility, researchers gathered data to examine the incidence of non-Hodgkin's lymphoma, multiple myeloma, chronic lymphatic leukemia, acute lymphatic leukemia, Hodgkin's lymphoma and thyroid cancer in the country's entire cohort of HCV patients.

For 27,150 HCV patients, the researchers modelled the date of HCV infection based on age and mode of transmission. They then collected data on the relevant cancer diagnoses among these patients from 1990 to 2000. Lastly, they performed statistical analyses to compare these patients' cancer rates to those of the entire Swedish population.

They found that the risk of both non-Hodgkin's lymphoma and multiple myeloma were significantly higher compared to the general population - 1.99 and 2.54 times higher, respectively. "The majority of the non-Hodgkin's lymphoma and multiple myeloma patients were estimated to have been infected more than 15 years, which is consistent with the theory that lymphomagenesis is a slow process and non-Hodgkin's lymphoma develops after a long influence," say the authors. They suggest that the risk for HCV-related malignancy increases with time of HCV infection.

In conclusion, "this is the first study of the incidence of non-Hodgkin's lymphoma, multiple myeloma, chronic lymphatic leukemia, acute lymphatic leukemia, Hodgkin's lymphoma and thyroid cancer in a nationwide cohort of HCV-infected persons," the authors report. "Although the delayed diagnosis of hepatitis C most probably has made us underestimate the risk, this study showed that the risk of B-cell non-Hodgkin's lymphoma and multiple myeloma were significantly increased."

http://www.interscience.wiley.com/journal/hepatology