Immunomodulatory Effect after Irreversible Electroporation in Patients with Locally Advanced Pancreatic Cancer

He, Chaobin; Wang, Jun; Sun, Shuxin; Zhang, Yu; Li, Shengping

Immune Parameters. For a more complete understanding of the IRE-associated alteration of immune, analyses of the plasma concentration of several cytokines were conducted. Marked changes were observed for interleukin-2 (IL-2) (p<0.05), IL-6 (p<0.001), and IL-10 (p<0.01). IRE dramatically increased circulating IL-6 and IL-10 at D3 but these decreased at D7 (all p<0.05). Although no changes of IL-2 at D3 were observed, there was a significant increase from D3 to D7 (p<0.05). On the contrary, IRE did not significantly alter plasma concentration of IFN-and TNF (p>0.05). Moreover, we analyzed the plasma concentration of several general humoral immune parameters (complement: C3 and C4; immunoglobulin: IgA, IgG, and IgM). C3, C4, and IgG notably decreased immediately after IRE (D3) (all p<0.05) but significantly increased within one week (all p<0.01). There were no significant changes for concentration of IgA and IgM (all p>0.05) (Figure 2 ). Abbreviations as in Table 1 . . Comparison of Survival Stratified by Changes of Immune Cells and Parameters. In the whole study cohort, there were 27 (79.4%) patients alive at the end of follow-up. The cumulative 1-year and 2-year OS rates were 69.9% and 52.4%, respectively. To evaluate the prognostic value of immune cells and parameters, the elevated or decreased group of these variables was defined by the threshold, which was the median value of the alterations between D3 and D7. In the subgroup analyses for OS, patients with an increase of CD4 + T cell (p=0.047), CD8 + T cell (p<0.001), and NK cell (p=0.013) or a decrease of Treg cell (p=0.015) had significant better OS than others. There were no significant differences with regard to OS when it was stratified by changes of cytokines, including IL-2, IL-6, and IL-10 (all p> . ). In addition to these variables, alteration of C3, C4, and IgG did not lead to significant differences in OS (all p> . ) ( Figure 3 ). Regarding PFS, significant survival benefit could be obtained from an increase of CD8 + T cell (p=0.048) while the alterations of other immune cells or parameters were not significantly associated with PFS (Figure 4) .