Indolent B-cell lymphomas treated upfront with antiviral therapy : a series of 13 patients

Background: HCV infection has been demonstrated to be involved in clonal B cell proliferation and in the subsequent development of non-Hodgkin's lymphoma (NHL). The regression of NHL after antiviral treatment is considered an indirect evidence of this pathogenetic relationship. Aim: to evaluate clinical course of patients affected by HCV infection (serology and HCV RNA positive) and low grade B-cell NHL (LG-NHL), not needing immediate treatment (absence of B symptoms, bulky disease or symptomatic tumor mass and lymphocyte doubling time less than 6 months) and treated upfront with antiviral therapy alone. Method: From 2006 to 2010, 13 patients, affected by LG- NHL at diagnosis have been treated with pegylated interferon (PegIFNa2a, 100–180 mcg weekly) and ribavirin (Rbv, 800–1200 mg daily) for a median treatment period of 6 months (6-18 months). Two patients are still in treatment. M/F ratio was 1.6 and median age was 59 years (range 51–73). The study included 9 marginal zone lymphomas (MZL: 2 splenic MZL, 7 extranodal non gastric MZL), 3 LG-NHL NOS and 1 lymphoplasmacytic lymphoma/Waldenstrom's macroglobulinemia (LPL). Cryoglobulin were present in five patients. 7 pts had genotype 2, 5 pts genotype 1b, one not assessed; HCV infection was detected before lymphoma diagnosis in 9 pts and at lymphoma onset in 4 pts. Only 2 patients have previously received other combinations of antiviral therapy. Virologic response was assessed monthly by HCV-RNA polymerase chain reaction (PCR) and hematologic response was evaluated according to International Working Group response criteria (Cheson et al. J Clin Oncol. 2007) at the end of antiviral therapy. Results: Eleven patients completed the planned treatment course. Sustained virologic response (SVR) was achieved in 9 patients (6 with genotype 2); viremia clearance was achieved in a median period of 2 months (1-6). Among patients that gained a SVR, 5 achieved a complete response (CR) (3 genotype 2, 1 1b, one not assessed), one (genotype 2) partial response (PR), and 3 (2 genotype 2 and one genotype 1b) presented stable disease (SD). The remaining patients obtained only a reduction of viremia: one presented a SD and one was in PR. The treatment was well tolerated without any WHO grade III-IV toxicity. Among patients that completed treatment program, more frequent toxicity was haematological (one patient developed a WHO grade 1 anemia and one patients developed WHO grade 1 anemia and grade 2 neutropenia). After a median follow up of 17 months from the end of therapy (range 3–44), considering the 9 patients in SVR, only 2 (1 CR and 1 PR) progressed, maintaining SVR and one lost SVR maintaining SD. Patients that obtained only a reduction of viremia, maintained their hematologic status. Conclusion: We described a high CR rate in patients that obtained SVR after antiviral therapy (55%); the relationship between hematologic and viral response during follow up is not always stringent. We confirm that antiviral therapy could be considered as frontline therapeutic option in cases of HCV-related LG-NHL not requiring immediately immunochemotherapy.