Hepatitis C: a risk factor for lymphoma

NEW YORK (Reuters Health) - Canadian researchers have confirmed an association between hepatitis C virus (HCV) infection and an increased risk of non-Hodgkin's lymphoma, according to their report in the International Journal of Cancer.

Dr. John J. Spinelli of the British Columbia Cancer Agency, Vancouver, and colleagues note that studies have indicated HCV infection may double the risk of non-Hodgkin's lymphoma. To investigate this relationship, the researchers conducted a population-based study in British Columbia, involving 795 patients with newly diagnosed lymphoma and 697 subjects without lymphoma.

In 2.4 percent of the patients with non-Hodgkin's lymphoma were also infected with HCV compared with 0.7 percent of the comparison subjects. The greatest non-Hodgkin's lymphoma risk was for diffuse large B-cell lymphoma and marginal zone lymphoma, with 7.3-fold and 6.1-times the risk.

The researchers note that the prevalence of HCV infection in the province, estimated to be about 1.5 percent, is nearly twice the national rate, "likely due to a high rate of injection drug use." Nevertheless, they point out, the non-Hodgkin's lymphoma risk for HCV infection remained after adjusting for injection drug use.

Spinelli told Reuters Health that a possible connection between HCV and non-Hodgkin's lymphoma was first suggested in the 1990s and subsequent investigation has helped to confirm this.

"Our study," he concluded, "provides further evidence that there is indeed an association between HCV infection and the risk of non-Hodgkin's lymphoma."

SOURCE: International Journal of Cancer, February 1, 2008.