Antiviral therapy with interferon, ribavirin cuts risk of HCV-related lymphoma
Antiviral treatment with pegylated interferon and ribavirin (PegIFN/RBV) leads to a significant reduction in the risk of lymphoma, especially the non-Hodgkin’s (NHL) type, in patients with chronic hepatitis C virus (HCV) infection, according to a study.
The risk reduction is predominantly observed in patients aged <60 years, and the risk of incident lymphoma or NHL is comparable to that in individuals without HCV, the investigators said.
“Thus, we suggest early antiviral therapy (<60 years) for chronic HCV,” they added.
The study included a propensity-matched cohort of patients who received PegIFN/RBV antiviral therapy for ≥24 weeks (n=24,133) or hepatoprotectants for ≥90 days without antiviral therapy (untreated group; n=24,133). The mean age of the cohort was 51 years, and 55 percent of them were males.
Lymphoma occurred with significantly greater frequency in the untreated vs the PegIFN/RBV group (78 vs 35 patients; NHL: 60 vs 28 patients) over a mean follow‐up of 4.86 and 3.35 years, respectively. The corresponding incidence rate for all lymphoma was 66.48 vs 43.34 per 100,000 person‐years (p=0.029). [Aliment Pharmacol Ther 2018;doi:10.1111/apt.15101]
On multivariable Cox regression analysis, PegIFN/RBV therapy was associated with a lower risk of developing lymphoma (hazard ratio [HR], 0.64; 95 percent CI, 0.43–0.96; p=0.030). This beneficial effect was pronounced in the subgroup of chronic HCV patients aged <60 years (HR, 0.49; 95 percent CI, 0.29‐0.82; p=0.007) and for NHL (HR, 0.52; 0.30–0.91; p=0.022).
Following antiviral therapy, the risk of developing lymphoma in the PegIFN/RBV group was similar to that in the non-HCV cohort (all lymphoma: 30.45 vs 25.44 per 100,000 person‐years; p=0.269; NHL: 27.24 vs 22.83 per 100,000 person‐years; p=0.225).
According to the authors, the finding that PegIFN/RBV did not reduce the risk of lymphoma in patients aged ≥60 years may be explained by the significantly greater number of comorbid diseases in older patients. Such comorbidities lead to a greater frequency of adverse events and poorer tolerance of PegIFN/RBV therapy, with an inferior sustained virologic response (SVR).
“[T]his suggests that eradication of HCV at a younger age may have an additional benefit in preventing lymphoma,” they continued.
Furthermore, the similar prognoses observed in chronic HCV patients who received ≥24 weeks of PegIFN/RBV treatment and individuals without the infection appear to indicate that interferon therapy may have a cytostatic effect on lymphoma.
“Because direct-acting antiviral (DAA) therapy increases SVR significantly, even in older patients, whether DAA‐induced HCV clearance has an increased magnitude of risk reduction of lymphoma or negates the age effect must be confirmed in further large‐scale studies,” they said.
The study, despite its large sample size, had several limitations. For the most part, there were no available data on laboratory results (eg, HCV genotypes) and treatment responses after PegIFN/RBV therapy, as the authors pointed out. “Finally, the immortal time bias should be considered when interpreting our results.”