*4.2.1.2 Volatile agents*

In vitro and in vivo studies have shown that there is an association between inhalation anesthesia and increased tumor spread [35–37]. In a recent retrospective study, conducted in 2016 by Wigmore et al. [36] cancer patients were found to have a worse survival outcome if they received inhalation anesthesia. Inhalational anesthetics suppress the immune system by decreasing the function of NK cells, which play an important role in protecting against the proliferation of cancer cells. Inhalational anesthetics induce apoptosis in lymphocytes, reduce NK cell-mediated cytotoxicity, and alter the elevation of cytokines generated by NK cells in response to tumor cells.
