Hepatitis C virus infection and non-Hodgkin lymphoma: interesting association or causal relationship?

摘要

Numerous population-based studies have demonstrated an association between hepatitis C virus (HCV) infection and non-Hodgkin lymphoma (NHL),1'2 pointing to the possibility that HCV plays a role in the development of this malignancy. The Scandinavia Lymphoma Etiology (SCALE) study, reported in this issue of the International Journal of Cancer, adds to the accumulating body of epi-demiological evidence supporting this association,. The large sample size (2,819 NHL cases and 1,856 controls), comprehensive population-based recruitment strategy, rapid case ascertainment, and detailed classification of NHL subtypes make SCALE one of the most comprehensive case-control studies to date,. One limitation of the SCALE study was the very low prevalence of HCV infection (0.4% of controls, even when the investigators included individuals with intermediate serologic evidence for infection), which limited the power and precision of some statistical analyses, HCV seroposi-tivity was associated, although not significantly, with overall NHL risk (OR 2.2, 95% CI 0.9-5.3), and was significantly associated with risk of B-cell lymphomas (OR 2.4, 95% CI 1.0-5.8), specifically lymphoplasmacytic lymphoma (OR 5 2, 95% CI 1.0-26.4). The findings of the SCALE study ate consistent with the prior literature, which now includes multiple case-control studies and several cohort studies, most of which find a positive association between HCV infection and NHL.