The immunomodulatory effect of ketamine in colorectal cancer surgery: a randomized-controlled trial

Perioperative Ketamine and Cancer Recurrence: A Comprehensive Review

Cancer is a significant global health threat and a leading cause of death worldwide. Effective early-stage interventions, particularly surgery, can potentially cure many solid tumors. However, the risk of postoperative cancer recurrence remains high. Recent research highlights the influence of perioperative anesthetic and analgesic choices on the fate of residual cancer cells, potentially affecting recurrence risks. Among these agents, ketamine-a well-known anesthetic and analgesic-has garnered interest due to its antitumor properties, mainly through inhibiting the N-methyl-D-aspartate (NMDA) receptor found in various cancer tissues. Additionally, ketamine's potential immunomodulatory effects, given the expression of NMDA receptors on immune cells, suggest that it plays a significant role during the perioperative period. This review synthesizes current evidence on ketamine's impact on cancer cell biology, inflammation, immune modulation, and the role of the gut microbiota, proposing ketamine as a promising agent for enhancing oncological outcomes.

PROcedure-SPECific postoperative pain management guideline for laparoscopic colorectal surgery: A systematic review with recommendations for postoperative pain management

Colorectal cancer is the second most common cancer diagnosed in women and third most common in men. Laparoscopic resection has become the standard surgical technique worldwide given its notable benefits, mainly the shorter length of stay and less postoperative pain. The aim of this systematic review was to evaluate the current literature on postoperative pain management following laparoscopic colorectal surgery and update previous procedure-specific pain management recommendations. The primary outcomes were postoperative pain scores and opioid requirements. We also considered study quality, clinical relevance of trial design, and a comprehensive risk-benefit assessment of the analgesic intervention. We performed a literature search to identify randomised controlled studies (RCTs) published before January 2022. Seventy-two studies were included in the present analysis. Through the established PROSPECT process, we recommend basic analgesia (paracetamol for rectal surgery, and paracetamol with either a nonsteroidal anti-inflammatory drug or cyclo-oxygenase-2-specific inhibitor for colonic surgery) and wound infiltration as first-line interventions. No consensus could be achieved either for the use of intrathecal morphine or intravenous lidocaine; no recommendation can be made for these interventions. However, intravenous lidocaine may be considered when basic analgesia cannot be provided.

Tumour excisional surgery, anaesthetic-analgesic techniques, and oncologic outcomes: a narrative review

Cancer is a growing global burden; there were an estimated 18 million new cancer diagnoses worldwide in 2020. Excisional surgery remains one of the main treatments for solid organ tumours in cancer patients and is potentially curative. Cancer- and surgery-induced inflammatory processes can facilitate residual tumour cell survival, growth, and subsequent recurrence. However, it has been hypothesised that anaesthetic and analgesic techniques during surgery might influence the risk of cancer recurrence. This narrative review aims to provide an updated summary of recent observational studies and new randomised controlled clinical trials on whether certain specific anaesthetic and analgesic techniques or perioperative interventions during tumour resection surgery of curative intent materially affect long-term oncologic outcomes.

Efficacy of intraoperative subanesthetic dose of ketamine/esketamine in preventing postoperative cognitive dysfunction: a systematic review and meta-analysis

Background

Postoperative cognitive dysfunction (POCD) is a common complication after anesthesia surgery, especially in older people, that can persist weeks or months after surgery as a short-term impairment of cognitive abilities, or even for a prolonged duration over years, potentially progressing into permanent cognitive dysfunction. However, the pathogenesis of POCD is not fully understood, and therefore an optimal solution for preventing POCD has yet to be established. Some studies have shown that intraoperative ketamine/esketamine reduces the incidence of POCD, but this remains controversial.

Objectives

We evaluated the effect of intraoperative subanesthetic doses of ketamine/esketamine versus no intervention in adults undergoing general anesthesia surgery on the incidence of POCD.

Data Sources

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and searched the PubMed, Embase, Ovid, Cochrane, Scopus, and Web of Science databases for the MeSH terms 'ketamine', 'esketamine', and 'Postoperative Cognitive Complications' from database inception to 25 June 2023.

Results

We found no statistically significant difference in the incidence of POCD within 7 days for intraoperative subanesthetic dose of ketamine/esketamine compared with the control group [relative risk (RR) = 0.57, 95% confidence interval (CI): 0.32, 1.01], and the results from the subgroup analysis based on age (>60 years) also revealed that the difference was not statistically significant (RR = 0.49, 95% CI: 0.23, 1.04).

Conclusion

Compared with controls, intraoperative subanesthetic dose of ketamine/esketamine has no advantage in preventing POCD in patients, or in elderly patients. This study provides reference data for POCD research and clinical drug intervention strategies.

Registration

Prospective Register of Systematic Reviews (PROSPERO; registration number CRD42023401159).

Efficacy and safety of perioperative application of ketamine on postoperative depression: A meta-analysis of randomized controlled studies

Ketamine, a commonly used general anesthetic, can produce rapid and sustained antidepressant effect. However, the efficacy and safety of the perioperative application of ketamine on postoperative depression remains uncertain. We performed a meta-analysis to determine the effect of perioperative intravenous administration of ketamine on postoperative depression. Randomized controlled trials comparing ketamine with placebo in patients were included. Primary outcome was postoperative depression scores. Secondary outcomes included postoperative visual analog scale (VAS) scores for pain and adverse effects associated with ketamine. Fifteen studies with 1697 patients receiving ketamine and 1462 controls were enrolled. Compared with the controls, the ketamine group showed a reduction in postoperative depression scores, by a standardized mean difference (SMD) of -0.97, 95% confidence interval [CI, -1.27, -0.66], P < 0.001, I2 = 72% on postoperative day (POD) 1; SMD-0.65, 95% CI [-1.12, -0.17], P < 0.001, I2 = 94% on POD 3; SMD-0.30, 95% CI [-0.45, -0.14], P < 0.001, I2 = 0% on POD 7; and SMD-0.25, 95% CI [-0.38, -0.11], P < 0.001, I2 = 59% over the long term. Ketamine reduced VAS pain scores on POD 1 (SMD-0.93, 95% CI [-1.58, -0.29], P = 0.005, I2 = 97%), but no significant difference was found between the two groups on PODs 3 and 7 or over the long term. However, ketamine administration distinctly increased the risk of adverse effects, including nausea and vomiting (risk ratio [RR] 1.40, 95% CI [1.12, 1.75], P = 0.003, I2 = 30%), headache (RR 2.47, 95% CI [1.41, 4.32], P = 0.002, I2 = 19%), hallucination (RR 15.35, 95% CI [6.24, 37.34], P < 0.001, I2 = 89%), and dizziness (RR 3.48, 95% CI [2.68, 4.50], P < 0.001, I2 = 89%) compared with the controls. In conclusion, perioperative application of ketamine reduces postoperative depression and pain scores with increased risk of adverse effects.

Effects of anesthetic depth on perioperative T lymphocyte subsets in patients undergoing laparoscopic colorectal cancer surgery: a prospective, parallel-controlled randomized trial

BACKGROUND

During the perioperative period, the surgical stress response induced by surgical trauma tends to cause a decrease in peripheral lymphocytes. Anesthetics could reduce the stress response during surgery and prevent sympathetic nerve overexcitation. The goal of this study was to investigate how BIS-guided anesthetic depth affected peripheral T lymphocytes in patients undergoing laparoscopic colorectal cancer surgery.

METHODS

A total of 60 patients having elective laparoscopic colorectal cancer surgery were randomly assigned and analyzed (n = 30 for deep general anesthesia, BIS 35, n = 30 for light general anesthesia, BIS 55). Blood samples were collected immediately before anesthesia induction and immediately after operation, 24 h and 5 days postoperatively. The CD4+/CD8 + ratio, T lymphocyte subsets (including CD3 + T cells, CD4 + T cells, and CD8 + T cells), and natural killer (NK) cells were analyzed by flow cytometry. Serum interleukin-6 (IL-6), interferon -ɣ (IFN-ɣ), and vascular endothelial growth factor-α (VEGF-α) were also measured.

RESULTS

The CD4+/CD8 + ratio decreased 24 h after surgery in two groups, but the reduction did not differ between the two groups (P > 0.05). The concentration of IL-6 and the numerical rating scale (NRS) score in the BIS 55 group were significantly higher than that in the BIS 35 group 24 h after surgery (P = 0.001). There were no intergroup differences in CD3 + T cells, CD4 + T cells, CD8 + T cells, NK cells, VEGF-α, or the IFN-ɣ. Statistical analyses showed no differences between the two groups in the incidence of fever and surgical site infection during hospitalization.

CONCLUSIONS

Despite the fact that patients in deep general anesthesia group had low levels of the IL-6 24 h after surgery, the deep general anesthesia was not associated to a positive effect on patients' peripheral T lymphocytes during colorectal cancer surgery. We found no evidence that peripheral T lymphocyte subsets and natural killer cells were affected by the targeting a BIS of either 55 or 35 in patients undergoing laparoscopic colorectal cancer surgery in this trial.

TRIAL REGISTRATION

ChiCTR2200056624 ( www.chictr.org.cn ).

Tumor Necrosis Factor Alpha: Implications of Anesthesia on Cancers

Cancer remains a major public health issue and a leading cause of death worldwide. Despite advancements in chemotherapy, radiation therapy, and immunotherapy, surgery is the mainstay of cancer treatment for solid tumors. However, tumor cells are known to disseminate into the vascular and lymphatic systems during surgical manipulation. Additionally, surgery-induced stress responses can produce an immunosuppressive environment that is favorable for cancer relapse. Up to 90% of cancer-related deaths are the result of metastatic disease after surgical resection. Emerging evidence shows that the interactions between tumor cells and the tumor microenvironment (TME) not only play decisive roles in tumor initiation, progression, and metastasis but also have profound effects on therapeutic efficacy. Tumor necrosis factor alpha (TNF-α), a pleiotropic cytokine contributing to both physiological and pathological processes, is one of the main mediators of inflammation-associated carcinogenesis in the TME. Because TNF-α signaling may modulate the course of cancer, it can be therapeutically targeted to ameliorate clinical outcomes. As the incidence of cancer continues to grow, approximately 80% of cancer patients require anesthesia during cancer care for diagnostic, therapeutic, or palliative procedures, and over 60% of cancer patients receive anesthesia for primary surgical resection. Numerous studies have demonstrated that perioperative management, including surgical manipulation, anesthetics/analgesics, and other supportive care, may alter the TME and cancer progression by affecting inflammatory or immune responses during cancer surgery, but the literature about the impact of anesthesia on the TNF-α production and cancer progression is limited. Therefore, this review summarizes the current knowledge of the implications of anesthesia on cancers from the insights of TNF-α release and provides future anesthetic strategies for improving oncological survival.

S-Ketamine attenuates inflammatory effect and modulates the immune response in patients undergoing modified radical mastectomy: A prospective randomized controlled trial

Objective: This study aimed to investigate the impact of varying dosages of S-ketamine on perioperative immune-inflammatory responses in patients undergoing modified radical mastectomy (MRM). Methods: This is a prospective, randomized, controlled trial. A total of 136 patients with American Society of Anesthesiologists status I/II scheduled for MRM were enrolled and randomly assigned into groups to receive the control (C) or one of three different doses [0.25 (L-Sk), 0.5 (M-Sk), or 0.75 (H-Sk) mg/kg] of S-ketamine. The primary outcomes were the cellular immune function and inflammatory factors before anesthesia and at the end of (T1) and 24 h (T2) after the surgery. Secondary outcomes included the visual analog scale (VAS) score, opioid consumption, rate of remedial analgesia, adverse events, and patient satisfaction. Results: The percentage and absolute counts of CD3⁺ and CD4⁺ cells in groups L-Sk, M-Sk, and H-Sk were higher than those of group C at T1 and T2. Moreover, a pairwise comparison revealed that the percentage in group H-Sk was higher than those in the L-Sk and M-Sk groups (p < 0.05). The ratio of CD4⁺/CD8⁺ was lower in group C at T1 and T2 than those in groups M-Sk and H-Sk (p < 0.05). There was no significant difference in the percentage and absolute counts of natural killer (NK) cells and B lymphocytes among the four groups. However, compared with group C, the concentrations of white blood cells (WBC), neutrophils (NEUT), hypersensitive C-reactive protein (hs-CRP), the neutrophil-to-lymphocyte ratio (NLR), systemic inflammation response index (SIRI), and systemic immune-inflammation index (SII) at T1 and T2 in three different doses of S-ketamine groups were significantly low, and the lymphocytes were significantly high. The ratio of SIRI and NLR at T2 in group M-Sk was lower than that in group L-Sk (p < 0.05). Additionally, a significant decrease in VAS score, opioid consumption, rates of remedial analgesia, and adverse events was observed in the M-Sk and H-Sk groups. Conclusion: Collectively, our study demonstrates that S-ketamine could reduce opioid consumption, decrease postoperative pain intensity, exert a systemic anti-inflammatory effect, and attenuate immunosuppression in patients undergoing MRM. Moreover, we found that the effects of S-ketamine are related to the dose used, with significant differences observed in 0.5 or 0.75 mg/kg of S-ketamine. Clinical Trial Registration: chictr.org.cn, identifier ChiCTR2200057226.

Drug Repurposing: The Mechanisms and Signaling Pathways of Anti-Cancer Effects of Anesthetics

Cancer is one of the leading causes of death worldwide. There are only limited treatment strategies that can be applied to treat cancer, including surgical resection, chemotherapy, and radiotherapy, but these have only limited effectiveness. Developing a new drug for cancer therapy is protracted, costly, and inefficient. Recently, drug repurposing has become a rising research field to provide new meaning for an old drug. By searching a drug repurposing database ReDO_DB, a brief list of anesthetic/sedative drugs, such as haloperidol, ketamine, lidocaine, midazolam, propofol, and valproic acid, are shown to possess anti-cancer properties. Therefore, in the current review, we will provide a general overview of the anti-cancer mechanisms of these anesthetic/sedative drugs and explore the potential underlying signaling pathways and clinical application of these drugs applied individually or in combination with other anti-cancer agents.

Immunological Insights into Opioid-Free Anaesthesia in Oncological Surgery: A Scoping Review

Purpose of Review

The influence of opioids on outcomes after cancer surgery when used, or avoided, intraoperatively remains unclear. There is a need to conduct a scoping review to explore the wider context and provide direction for future research. The review will examine the current state of evidence in humans, with a focus on immunological biomarkers and clinically relevant cancer outcomes in trials comparing opioid-free to opioid-based general anaesthesia.

Recent Findings

There is limited research on this subject area, which is mainly focused on breast cancer. The most frequently evaluated immunological parameter is the neutrophil-to-lymphocyte ratio. Cancer outcomes are mainly focused on recurrence.

Summary

The central knowledge gap is understanding how the cellular effects of opioids translate into longer-term patient outcomes. The major challenge for future research is accounting for the immunomodulatory effects of a wide range of confounding factors, which have yet to be clarified.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11912-022-01300-5.

Anesthesia and Oncology: Friend or Foe?

Cancer is a leading cause of death, and surgery is an important treatment modality. Laboratory research and retrospective studies have raised the suspicion that the choice of anesthetics for cancer surgery might affect the course of cancerous disease. The aim of this review is to provide a critical overview of the current state of knowledge. Inhalational anesthesia with volatiles or total intravenous anesthesia (TIVA) with propofol are the two most commonly used anesthetic techniques. Most data comparing volatile anesthetics with TIVA is from either in vitro or retrospective studies. Although conflicting, data shows a trend towards favoring propofol. Opioids are commonly used in anesthesia. Data on potential effects of opioids on growth and recurrence of cancer are scarce and conflicting. Preclinical studies have shown that opioids stimulate cancer growth through the µ-opioid receptor. Opioids also act as immunosuppressants and, therefore, have the potential to facilitate metastatic spread. However, the finding of an adverse effect of opioids on tumor growth and cancer recurrence by some retrospective studies has not been confirmed by prospective studies. Regional anesthesia has not been found to have a beneficial effect on the outcome of surgically treated cancer patients, but prospective studies are scarce. Local anesthetics might have a beneficial effect, as observed in animal and in vitro studies. However, prospective clinical studies strongly question such an effect. Blood products, which may be needed during extensive cancer surgery suppress the immune system, and data strongly suggest a negative impact on cancer recurrence. The potential effects of other commonly used anesthetic agents on the outcome of cancer patients have not been sufficiently studied for drawing valid conclusions. In conclusion, laboratory data and most retrospective studies suggest a potential advantage of TIVA over inhalational anesthesia on the outcome of surgical cancer patients, but prospective, randomized studies are missing. Given the state of weak scientific evidence, TIVA may be used as the preferred type of anesthesia unless there is an individual contraindication against it. Studies on the effects of other drugs frequently used in anesthesia are limited in number and quality, and have found conflicting results.

Ketamine inhibits TNF-α-induced cecal damage by enhancing RIP1 ubiquitination to attenuate lethal SIRS

Systemic inflammatory response syndrome (SIRS) is a sepsis-associated inflammatory state and a self-defense mechanism against specific and nonspecific stimuli. Ketamine influences many key processes that are altered during sepsis. However, the underlying mechanisms remain incompletely understood. In this study, TNF-α-treated mice, as well as HT-29 and L929 cell models, were applied to characterize TNF-α-induced systemic and local cecal tissue inflammatory responses. Behavioral, biochemical, histological, and molecular biological approaches were applied to illustrate the related processes. Mice with TNF-α-induced SIRS showed systemic and local cecal tissue inflammatory responses, as indicated by increased levels of high mobility group box 1 protein (HMGB1), chemokines (C-X-C motif) ligand 10 (CXCL10), interleukin-6 (IL-6), and IL-10, as well as high mortality. Ketamine pretreatment alleviated death rates, symptoms, and the production of inflammatory cytokines induced by TNF-α in mice. Moreover, ketamine also protected the mice from TNF-α-induced cecal damage by suppressing the phosphorylation of receptor-interacting serine/threonine-protein kinase 3 (RIP3) and mixed lineage kinase domain-like protein (MLKL). In addition, our results showed that ketamine efficiently inhibited TNF-α-induced necroptosis in HT-29 and L929 cells. Furthermore, we explored the mechanism using different L929 cell lines. The results displayed that ketamine inhibited TNF-α-induced necroptosis by enhancing RIP1 ubiquitination and reducing the RIP1-RIP3 and RIP3-MLKL interactions, as well as the formation of necrosomes. Thus, our study may provide a new theoretical and experimental basis for treating diseases characterized by SIRS-associated inflammatory factor storms. Moreover, our exploration may provide potential molecular mechanisms and targets for therapeutic intervention and clinical application of ketamine.

Can Acute Postoperative Pain Management After Tumour Resection Surgery Modulate Risk of Later Recurrence or Metastasis?

Background

Cancer is a leading cause of mortality worldwide, but death is rarely from the primary tumour: Rather it is multi-organ dysfunction from metastatic disease that is responsible for up to 90% of cancer-related deaths. Surgical resection of the primary tumour is indicated in 70% of cases. The perioperative stress response, tissue hypoxia at the site of surgery, and acute pain contribute to immunosuppression and neo-angiogenesis, potentially promoting tumour survival, proliferation, and metastasis. Poorly controlled acute postoperative pain decreases Natural Killer (NK) immune cell activity, which could potentially facilitate circulating tumour cells from evading immune detection. This consequently promotes tumour growth and distal metastasis.

Methods

We conducted a comprehensive literature search for links between acute pain and cancer outcomes using multiple online databases. Relevant articles from January 1st, 2010 to September 1st, 2021 were analysed and appraised on whether postoperative pain control can modulate the risk of recurrence, metastasis, and overall cancer survival.

Results

Although experimental and retrospective clinical data suggest a plausible role for regional anaesthesia in cancer outcome modulation, this has not been supported by the single, largest prospective trial to date concerning breast cancer. While there are mixed results on anaesthesiology drug-related interventions, the most plausible data relates to total intravenous anaesthesia with propofol, and to systemic administration of lidocaine.

Conclusion

The hypothesis that anaesthetic and analgesic technique during cancer surgery could influence risk of subsequent recurrence or metastasis has been prevalent for >15 years. The first, large-scale definitive trial among women with breast cancer found robust equivalent findings between volatile anaesthesia with opioid analgesia and regional anaesthesia. Therefore, while regional anaesthesia during tumour resection does not seem to have any effect on cancer outcomes, it remains plausible that other anaesthetic techniques (e.g. total intravenous anaesthesia and systemic lidocaine infusion) might influence oncologic outcome in other major tumour resection surgery (e.g. colorectal and lung). Therefore, another large trial is needed to definitively answer these specific research questions. Until such evidence is available, perioperative analgesia for cancer surgery of curative intent should be based on patient co-morbidity and non-cancer endpoints, such as optimising analgesia and minimising postoperative complications.

Perioperative pain, analgesics and cancer-related outcomes: where do we stand?

Cancer-related pain is one of the most common and debilitating symptoms among cancer patients. Undertreated cancer-related pain interferes with daily activities and increases morbidity and mortality. While opioids continue to play an essential role in treating moderate to severe cancer-related pain, they are associated with many adverse effects including misuse. While preclinical and retrospective studies have shown a negative association between opioid use and cancer outcomes, randomized control trials demonstrate that opioid use does not influence cancer recurrence. Additionally, analgesics and adjuvants used for perioperatively or chronic pain control are unlikely to improve oncological outcomes. This article focuses on the pharmacological management of cancer-related pain and offers an overview regarding the use of these medications perioperatively and the cancer outcomes.