Lymphomas associated with chronic hepatitis C virus infection: A prospective multicenter cohort study from the Rete Ematologica Lombarda (REL) clinical network.

Chronic hepatitis C virus (HCV) infection is related with an increased risk of non-Hodgkin lymphomas (NHL). In indolent subtypes, regression of NHL was reported after HCV eradication with antiviral therapy (AT). In 2008 in Lombardy, a region of Northern Italy, the "Rete Ematologica Lombarda" (REL, Hematology Network of Lombardy-Lymphoma Workgroup) started a prospective multicenter observational cohort study on NHL associated with HCV infection, named "Registro Lombardo dei Linfomi HCV-positivi" ("Lombardy Registry of HCV-associated non-Hodgkin lymphomas"). Two hundred fifty patients with a first diagnosis of NHL associated with HCV infection were enrolled; also in our cohort, diffuse large B cell lymphoma (DLBCL) and marginal zone lymphoma (MZL) are the two most frequent HCV-associated lymphomas. Two thirds of patients had HCV-positivity detection before NHL; overall, NHL was diagnosed after a median time of 11 years since HCV survey. Our data on eradication of HCV infection were collected prior the recent introduction of the direct-acting antivirals (DAAs) therapy. Sixteen patients with indolent NHL treated with interferon-based AT as first line anti-lymphoma therapy, because of the absence of criteria for an immediate conventional treatment for lymphoma, had an overall response rate of 90%. After a median follow-up of 7 years, the overall survival (OS) was significantly longer in indolent NHL treated with AT as first line (P = 0.048); this confirms a favorable outcome in this subset. Liver toxicity was an important adverse event after a conventional treatment in 20% of all patients, in particular among DLBCL, in which it is more frequent the coexistence of a more advanced liver disease. Overall, HCV infection should be consider as an important co-pathology in the treatment of lymphomas and an interdisciplinary approach should be always considered, in particular to evaluate the presence of fibrosis or necroinflammatory liver disease.