Direct-acting antivirals (daas) increase the serum vegf level in patients with chronic hepatitis c: a rationale for tumor recurrence

The currently available novel combinations of DAAs have completely changed the panorama of hepatitis C therapy. As a result, current HCV infection cure rates have exceeded 90% in a very short time. Data on compensated cirrhosis show rates of sustained virological response (SVR) of around 95-97%, although this is a little lower in more advanced liver diseases. However, some authors reported that hepatocellular carcinoma (HCC) seems to develop within weeks or few months of starting treatment with direct-acting antivirals (DAAs). They reported for the first time that patients with cirrhosis and very early HCCs (single tumor <2 cm) or early HCCs with a low to moderate risk of recurrence showed a probability of recurrence at 4 months of between 17.6 and 21.5%; however, the recurrence rate was double the expected rate. On the other hand, some authors considered it unlikely that DAAs have an effect on tumor recurrence. A French group analyzed 307 chronic HCV patients with HCC who were treated with DAAs in 3 different cohorts; they concluded that there was no increased risk of HCC recurrence. It is well established that angiogenesis is a major driver of tumor dissemination and that VEGF is a critical player in liver cancer angiogenesis. VEGF levels in HCC tissues or in circulation correlate with more aggressive disease; therefore this research was aimed at monitoring the serum level of vascular endothelial growth factor (VEGF) and changes in the pattern of circulating interleukins in 103 chronic hepatitis C patients during antiviral treatment with DAA-regimens. VEGF, epidermal growth factor (EGF), and interleukins (IL-6, IL-10, IL-8, TNF alpha) were assessed at baseline, during treatment, and after treatment. The biological effect of DAA-treated patient serum on human umbilical vein endothelial cell (HUVEC) and Hepa RG cell proliferation in the presence of anti-VEGF monoclonal antibody, bevacizumab, was also confirmed. The median log10VEGF was significantly increased at 4 weeks after initiation of therapy (from 2.18 log10 pg/mL to 2.45 log10 pg/mL, p<0.001), remaining higher at the end of treatment (2.44 log10 pg/mL, p<0.001 vs. T0), and decreasing to the baseline value upon treatment discontinuation (2.13 log10 pg/mL at SVR4 and 2.28 log10 pg/mL at SVR12) On the other hand, EGF levels also increased during DAA treatment and subsequently decreased at SVR12; however, this trend was not significant. The temporal trends of the 2 main inflammatory cytokines, namely IL-10 and TNF-alpha, were different. At 4 weeks, IL-10 significantly decreased (from 1.44 pg/mL to 0.83 pg/mL; p=0.03), whereas TNF-alpha levels remained stable (from 4.05 pg/mL to 4.01 pg/mL, p=0.27). Interestingly, while IL-10 levels were substantially suppressed from the end of treatment onwards, the decrease in TNF-alpha started later; it was nearly significant at the end of treatment (2.82 pg/mL, p=0.05) and this was confirmed, although with a smaller decrease, at each consecutive time point (2.19 pg/mL and 2.09 pg/mL at SVR4 and 12, respectively). No difference in IL-8 and IL-6 levels was observed during treatment. The biological activity of sera collected from patients treated with DAAs on human endothelial cells (HUVEC) and Hepa RG was also investigated. HUVEC proliferation was measured upon stimulation with cell medium supplemented with sera obtained from patients receiving therapy. A significant induction of HUVEC proliferation was observed upon supplementation of media with sera from patients receiving DAA therapy (mean: 290±60% vs. 120±30, p<0.0001). Moreover, consistent with the reduction of VEGF upon treatment withdrawal, HUVEC proliferation was comparable to baseline in cell cultures supplemented with sera collected 12 weeks after treatment interruption. Of note, the peak of HUVEC stimulation upon addition of patient sera was comparable to maximal HUVEC stimulation under standard culture conditions The addition of serum from patients collected during therapy induced HepaRG proliferation that was partially inhibited (decrease of 50%) by bevacizumab; the effect disappeared 4 weeks after the end of therapy (SVR4). These results suggest that additional factors may be involved in the cellular growth observed after supplementation with sera collected during antiviral therapy.