Even decade ago it was believed that the choice method of anesthesia did not affect the course of the oncological process, but recent evidence has begun to emerge that inhalation anesthesia vs TIVA is associated with a higher number of adverse outcomes. Apparently, it makes sense to conduct mRCT in order to assess the effect of IA on immune system in patients operated on for breast cancer comprehensively. The results of that kind of RCT may finally give us an answer whether the choice of anesthesia affects the immune status of patients undergoing surgery for breast cancer. The evaluation of complications and long-term survival will allow to recommend to use or not to use IA for this type of surgery.

Objective: The Impact of Inhalation vs Total Intravenous Anesthesia on the Immune Status and Mortality in Patients Undergoing Breast Cancer Surgery

The power calculation for this study was based on an assessment of Neutrophil-lymphocyte ratio (NLR) in patients undergoing breast cancer resection with total intravenous and inhalation anesthesia in two studies:

1. Cho J.S. et al., 2017 - 48 patients (PMID: 28924368, TIVA group: NLR = 3.37 ± 1.27; inhalation group: NLR = 3.85 ± 1.46)
2. Ní Eochagáin A. et al., 2018 - 116 patients (PMID: 29457215, TIVA group: NLR = 3.20 ± 1.37; inhalation group: NLR = 4.10 ± 1.90).

The pooled mean NLR in the TIVA group is 3.25±1.34, in the inhalation anesthesia group: 4.03±1.78.

Difference in means (effect size): 0.78, for level α=0.05, power 1-β=80% and expected standard deviation of 1.5, 65 patients in each group should be recruited, taking into account a 10% margin (total number of patients: 130).

Inclusion Criteria:

• The age of the patients is from 45 to 74 years;
• Primary operable breast cancer (BC) without prior chemotherapy;
• Cytologically confirmed breast malignant tumor of IA-IIA stages (T1-2, N0, M0);
• Signed informed consent.

Exclusion Criteria:

• Acute cerebrovascular accident (CVA) occurred in the previous 6 months;
• Myocardial infarction (MI) occurred in the previous 6 months;
• Acute arterial thrombosis occurred in the previous 6 months;
• Acute venous thromboembolism occurred in the previous 6 months;
• Subarachnoid hemorrhage occurred during the previous 3 months;
• Chronic kidney disease (CKD) stage 3B-5;
• Сhronic heart failure (NYHA) class 3-4;
• Pregnancy;
• History of another location cancer;
• History of drug addiction;
• Autoimmune diseases in history;
• Post-randomization: withdrawal of informed consent (refusal to continue participating in the study);
• Post-randomization: surgical intervention, performed not in full (verified non-resected lesions in the early p/o period, 2 weeks p/o).