The antitumor effects of natural killer cells, helper T cells, and cytotoxic T cells after cancer surgery were reported previously. This study hypothesized that propofol-based anesthesia would have fewer harmful effects on immune cells than volatile anesthetics–based anesthesia during colorectal cancer surgery.
In total, 153 patients undergoing colorectal cancer surgery were randomized and included in the analysis. The primary outcome was the fraction of circulating natural killer cells over time in the propofol and sevoflurane groups. The fractions of circulating natural killer, type 1, type 17 helper T cells, and cytotoxic T cells were investigated. The fractions of CD39 and CD73 expressions on circulating regulatory T cells were investigated, along with the proportions of circulating neutrophils, lymphocytes, and monocytes.
The fraction of circulating natural killer cells was not significantly different between the propofol and sevoflurane groups until 24 h postoperatively (20.4 ± 13.4% vs. 20.8 ± 11.3%, 17.9 ± 12.7% vs. 20.7 ± 11.9%, and 18.6 ± 11.6% vs. 21.3 ± 10.8% before anesthesia and after 1 and 24 h after anesthesia, respectively; difference [95% CI], –0.3 [–4.3 to 3.6], –2.8 [–6.8 to 1.1], and –2.6 [–6.2 to 1.0]; P = 0.863, P = 0.136, and P = 0.151 before anesthesia and after 1 and 24 h, respectively). The fractions of circulating type 1 and type 17 helper T cells, cytotoxic T cells, and CD39+ and CD73+ circulating regulatory T cells were not significantly different between the two groups. The neutrophil to lymphocyte ratio in both groups remained within the normal range and was not different between the groups.
Propofol-based anesthesia was not superior to sevoflurane-based anesthesia in terms of alleviating suppression of immune cells including natural killer cells and T lymphocytes during colorectal cancer surgery.
- Experimental studies alongside clinical trials yielded contradictory observations on the potential antitumor effects of intravenous- versus volatile anesthetics–based anesthesia regimens in the context of colorectal cancer surgery
- Various immune cells have been suggested to exert antitumor effects during the perioperative period
- The question whether propofol- versus sevoflurane-based anesthesia differentially affects circulating immune cells during colorectal cancer surgery is incompletely explored
- In this randomized controlled trial, the fraction of circulating natural killer cells and T lymphocytes was comparable between propofol- and sevoflurane-based anesthesia in patients undergoing colorectal cancer surgery
- These observations suggest that the type of general anesthetics used may minimally affect perioperative immune status