Effects of anesthetic technique and surgery on myeloid-derived suppressor cells and prognosis in women who underwent breast cancer surgery: a prospective study

Background: Surgery and anesthesia-induced immunosuppression may play a critical role in tumor progression and metastasis. Myeloid-derived suppressor cells (MDSCs) are highly immunosuppressive myeloid cells, closely linked with tumor staging, clinical therapeutic efficacy and prognosis. This study aims to investigate the effect of anesthetic technique and surgery on the expression of MDSCs and prognosis in women who received breast cancer surgery. Methods: From March 2016 to January 2017, a total of 80 patients with breast cancer were prospectively enrolled and randomized into two anesthetic groups: sevoflurane-based anesthetic group (SEV; n=38) and propofol-based total intravenous anesthetic group (TIVA; n=42). The expression of MDSCs and prognosis between different anesthetic techniques and stresses of surgical methods were compared. The primary endpoint is the postoperative expression of MDSCs and prognosis between SEV and TIVA groups. The secondary endpoint is the VAS scores at 24 hr post-operation between SEV and TIVA groups. Results: There was no significant difference in postoperative expression of MDSCs (P=0.202) and prognosis (P=0.138) between SEV and TIVA groups. Compared to breast-conserving surgery (BCS), patients who underwent breast mastectomy had significantly fewer MDSCs (P=0.040) and lower VAS score at 24 hr post-operation (P=0.044), while no significant difference in prognosis was found (P=0.953). When MDSCs were classified as subtypes of granulocytic/polymorphonuclear (PMN)-MDSCs and monocytic (Mo)-MDSCs, it showed higher ratio of Mo-MDSCs (P=0.018) or lower ratio of (PMN)-MDSCs (P=0.022) correlates to later tumor stage. Conclusion: Sevoflurane and propofol-based anesthesia do not show significant difference in MDSCs expression and prognosis after breast cancer surgery. Compared to BCS, although mastectomy with high extent of surgical stress exhibits lower levels of MDSCs, there is no significant difference in prognosis. The ratio of MDSCs subtype correlates to tumor stage.