Comparison between epidural and intravenous analgesia effects on disease-free survival after colorectal cancer surgery: a randomised multicentre controlled trial

Post-diagnosis adiposity and colorectal cancer prognosis: A Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis

The adiposity influence on colorectal cancer prognosis remains poorly characterised. We performed a systematic review and meta-analysis on post-diagnosis adiposity measures (body mass index [BMI], waist circumference, waist-to-hip ratio, weight) or their changes and colorectal cancer outcomes. PubMed and Embase were searched through 28 February 2022. Random-effects meta-analyses were conducted when at least three studies had sufficient information. The quality of evidence was interpreted and graded by the Global Cancer Update Programme (CUP Global) independent Expert Committee on Cancer Survivorship and Expert Panel. We reviewed 124 observational studies (85 publications). Meta-analyses were possible for BMI and all-cause mortality, colorectal cancer-specific mortality, and cancer recurrence/disease-free survival. Non-linear meta-analysis indicated a reverse J-shaped association between BMI and colorectal cancer outcomes (nadir at BMI 28 kg/m2). The highest risk, relative to the nadir, was observed at both ends of the BMI distribution (18 and 38 kg/m2), namely 60% and 23% higher risk for all-cause mortality; 95% and 26% for colorectal cancer-specific mortality; and 37% and 24% for cancer recurrence/disease-free survival, respectively. The higher risk with low BMI was attenuated in secondary analyses of RCTs (compared to cohort studies), among studies with longer follow-up, and in women suggesting potential methodological limitations and/or altered physiological state. Descriptively synthesised studies on other adiposity-outcome associations of interest were limited in number and methodological quality. All the associations were graded as limited (likelihood of causality: no conclusion) due to potential methodological limitations (reverse causation, confounding, selection bias). Additional well-designed observational studies and interventional trials are needed to provide further clarification.

The role of lidocaine in cancer progression and patient survival

Since its development in 1943, lidocaine has been one of the most commonly used local anesthesia agents for surgical procedures. Lidocaine alters neuronal signal transmission by prolonging the inactivation of fast voltage-gated sodium channels in the cell membrane of neurons, which are responsible for action potential propagation. Recently, it has attracted attention due to emerging evidence suggesting its potential antitumor properties, particularly in the in vitro setting. Further, local administration of lidocaine around the tumor immediately prior to surgical removal has been shown to improve overall survival in breast cancer patients. However, the exact mechanisms driving these antitumor effects remain largely unclear. In this article, we will review the existing literature on the mechanism of lidocaine as a local anesthetic, its effects on the cancer cells and the tumor microenvironment, involved pathways, and cancer progression. Additionally, we will explore recent reports highlighting its impact on clinical outcomes in cancer patients. Taken together, there remains significant ambiguity surrounding lidocaine's functions and roles in cancer biology, particularly in perioperative setting.

Impact of spinal or epidural anaesthesia on perioperative outcomes in adult noncardiac surgery: a narrative review of recent evidence

Spinal and epidural anaesthesia and analgesia are important anaesthetic techniques, familiar to all anaesthetists and applied to patients undergoing a range of surgical procedures. Although the immediate effects of a well-conducted neuraxial technique on nociceptive and sympathetic pathways are readily observable in clinical practice, the impact of such techniques on patient-centred perioperative outcomes remains an area of uncertainty and active research. The aim of this review is to present a narrative synthesis of contemporary clinical science on this topic from the most recent 5-year period and summarise the foundational scholarship upon which this research was based. We searched electronic databases for primary research, secondary research, opinion pieces, and guidelines reporting the relationship between neuraxial procedures and standardised perioperative outcomes over the period 2018-2023. Returned citation lists were examined seeking additional studies to contextualise our narrative synthesis of results. Articles were retrieved encompassing the following outcome domains: patient comfort, renal, sepsis and infection, postoperative cancer, cardiovascular, and pulmonary and mortality outcomes. Convincing evidence of the beneficial effect of epidural analgesia on patient comfort after major open thoracoabdominal surgery outcomes was identified. Recent evidence of benefit in the prevention of pulmonary complications and mortality was identified. Despite mechanistic plausibility and supportive observational evidence, there is less certain experimental evidence to support a role for neuraxial techniques impacting on other outcome domains. Evidence of positive impact of neuraxial techniques is best established for the domains of patient comfort, pulmonary complications, and mortality, particularly in the setting of major open thoracoabdominal surgery. Recent evidence does not strongly support a significant impact of neuraxial techniques on cancer, renal, infection, or cardiovascular outcomes after noncardiac surgery in most patient groups.

Pain management after open colorectal surgery: An update of the systematic review and procedure-specific postoperative pain management (PROSPECT) recommendations

BACKGROUND

Open colectomy is still performed around the world and associated with significant postoperative pain.

OBJECTIVES

Unpublished recommendations based on a systematic review were proposed by the PROcedure SPECific postoperative pain managemenT (PROSPECT) group in 2016. We aimed to update these recommendations by evaluating the available literature and develop recommendations for optimal pain management after open colectomy according to the PROSPECT methodology.

DESIGN AND DATA SOURCES

A systematic review using the PROSPECT methodology was undertaken. Randomised controlled trials and systematic reviews published in the English language from 2016 to 2022 assessing postoperative pain after open colectomy using analgesic, anaesthetic or surgical interventions were identified. The primary outcome included postoperative pain scores.

RESULTS

The previous 2016 review included data from 93 studies. Out of 842 additional eligible studies identified, 13 new studies were finally retrieved for analysis. Intra-operative and postoperative interventions that improved postoperative pain were paracetamol, epidural analgesia. When epidural is not feasible, intravenous lidocaine or bilateral TAP block or postoperative continuous pre-peritoneal infusion are recommended. Intra-operative and postoperative Cyclo-oxygenase (COX)-2 specific-inhibitors or non-steroidal anti-inflammatory drugs (NSAIDs) are recommended for colonic surgery.

CONCLUSIONS

The analgesic regimen for open colectomy should include intra-operative paracetamol and COX-2 specific inhibitors or NSAIDs (restricted to colonic surgery), epidural and continued postoperatively with opioids used as rescue analgesics. If epidural is not feasible, bilateral TAP block or IV lidocaine are recommended. Safety issues should be highlighted: local anaesthetics should not be administered by two different routes at the same time. Because of the risk of toxicity, careful dosing and monitoring are necessary.

Comparison between the effects of epidural and intravenous patient-controlled analgesia on postoperative disability-free survival in patients undergoing thoracic and abdominal surgery: A post hoc analysis

BACKGROUND

Thoracic epidural analgesia (TEA) and intravenous patient-controlled analgesia (IV-PCA) are widely used to mitigate immediate postoperative pain; however, their effects on long-term disability-free survival are poorly documented. This study aimed to compare the effects of postoperative TEA and IV-PCA on disability-free survival in patients who underwent thoracic or abdominal surgery.

METHODS

This post hoc analysis of a prospective observational study included 845 inpatients aged ≥55 years that underwent elective thoracic and abdominal surgery between 1 April 2016 and 28 December 2018 in a tertiary care hospital. Inverse probability of treatment weighted (IPTW) using stabilized inverse propensity scores was adopted to minimize bias. The primary outcome in this study was disability-free survival, defined as survival with a 12-item World Health Organization Disability Assessment Schedule 2.0 score of <16%, assessed at 3 months and 1 year after surgery.

RESULTS

The final analysis included 601 patients who received TEA and 244 who received IV-PCA. After IPTW, the weighted incidence of disability-free survival at 3 months and 1 year was 60.5% and 61.4% in the TEA group and 78.3% and 66.2% in the IV-PCA group, respectively. The adjusted OR for disability-free survival at 3 months and 1 year was 0.84 (95% confidence interval [CI]: 0.50-1.39) and 1.21 (95% CI: 0.72-2.05), respectively, for the TEA group.

CONCLUSION

No significant differences were observed in the disability-free survival at 3 months and 1 year after elective thoracic and abdominal surgery in patients aged ≥55 years who received TEA or IV-PCA.

SIGNIFICANCE STATEMENT

This study is the first in our setting to document the long-term effects of patient-controlled analgesia. In a post hoc analysis of our prospective cohort study, we show that although differences in chronic postsurgical pain exist at 3 months post-surgery, disability-free survival rates at 1 year do not differ irrespective of the choice of patient-controlled analgesia. The findings of this study highlight the need for shared decision-making between clinicians and patients.

Trial watch: local anesthetics in cancer therapy

Preclinical evidence indicates potent antitumor properties of local anesthetics. Numerous underlying mechanisms explaining such anticancer effects have been identified, suggesting direct cytotoxic as well as indirect immunemediated effects that together reduce the proliferative, invasive and migratory potential of malignant cells. Although some retrospective and correlative studies support these findings, prospective randomized controlled trials have not yet fully confirmed the antineoplastic activity of local anesthetics, likely due to the intricate methodology required for mitigating confounding factors. This trial watch aims at compiling all published preclinical and clinical research, along with completed and ongoing trials, that explore the potential antitumor effects of local anesthetics.

Immunocyte profiling changes in patients received epidural versus intravenous analgesia after pancreatectomy: A randomized controlled trial

BACKGROUND

Perioperative immunosuppressants, such as surgical stress and opioid use may downregulate anti-cancer immunocytes for patients undergoing pancreatectomy. Thoracic epidural analgesia (TEA) may attenuate these negative effects and provide better anti-cancer immunocyte profile change than intravenous analgesia using opioid.

METHODS

We randomly assigned 108 adult patients undergoing pancreatectomy to receive one of two 72-h postoperative analgesia protocols: one was TEA, and the other was intravenous patient-controlled analgesia (IV-PCA). The perioperative proportional changes of immunocytes relevant to anticancer immunity-namely natural killer (NK) cells, cytotoxic T cells, helper T cells, mature dendritic cells, and regulatory T (Treg) cells were determined at 1 day before surgery, at the end of surgery and on postoperative day 1,4 and 7 using flow cytometry. In addition, the progression-free survival and overall survival between the two groups were compared.

RESULTS

After surgery, the proportions of NK cells and cytotoxic T cells were significantly decreased; the proportion of B cells and mature dendritic cells and Treg cells were significantly increased. However, the proportions of helper T cells exhibited no significant change. These results were comparable between the two groups. Furthermore, there were no significant differences in progression-free survival (52.75 [39.96] and 57.48 [43.66] months for patients in the TEA and IV-PCA groups, respectively; p = 0.5600) and overall survival (62.71 [35.48] and 75.11 [33.10] months for patients in the TEA and IV-PCA groups, respectively; p = 0.0644).

CONCLUSIONS

TEA was neither associated with favorable anticancer immunity nor favorable oncological outcomes for patients undergoing pancreatectomy.

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.

Effect of different anesthetic modalities with multimodal analgesia on postoperative pain level in colorectal tumor patients

BACKGROUND

According to clinical data, a significant percentage of patients experience pain after surgery, highlighting the importance of alleviating postoperative pain. The current approach involves intravenous self-control analgesia, often utilizing opioid analgesics such as morphine, sufentanil, and fentanyl. Surgery for colorectal cancer typically involves general anesthesia. Therefore, optimizing anesthetic management and postoperative analgesic programs can effectively reduce perioperative stress and enhance postoperative recovery. The study aims to analyze the impact of different anesthesia modalities with multimodal analgesia on patients' postoperative pain.

AIM

To explore the effects of different anesthesia methods coupled with multi-mode analgesia on postoperative pain in patients with colorectal cancer.

METHODS

Following the inclusion criteria and exclusion criteria, a total of 126 patients with colorectal cancer admitted to our hospital from January 2020 to December 2022 were included, of which 63 received general anesthesia coupled with multi-mode labor pain and were set as the control group, and 63 received general anesthesia associated with epidural anesthesia coupled with multi-mode labor pain and were set as the research group. After data collection, the effects of postoperative analgesia, sedation, and recovery were compared.

RESULTS

Compared to the control group, the research group had shorter recovery times for orientation, extubation, eye-opening, and spontaneous respiration (P < 0.05). The research group also showed lower Visual analog scale scores at 24 h and 48 h, higher Ramany scores at 6 h and 12 h, and improved cognitive function at 24 h, 48 h, and 72 h (P < 0.05). Additionally, interleukin-6 and interleukin-10 levels were significantly reduced at various time points in the research group compared to the control group (P < 0.05). Levels of CD3+, CD4+, and CD4+/CD8+ were also lower in the research group at multiple time points (P < 0.05).

CONCLUSION

For patients with colorectal cancer, general anesthesia coupled with epidural anesthesia and multi-mode analgesia can achieve better postoperative analgesia and sedation effects, promote postoperative rehabilitation of patients, improve inflammatory stress and immune status, and have higher safety.

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.

Effect of regional anesthesia and analgesia on long-term survival following abdominal cancer Surgery-A systematic review with meta-analysis

Background

The impact of regional anesthesia and analgesia (RAA) on long-term survival following cancer surgery is a topic of debate. The aim of this study was to investigate the effects of perioperative RAA on long-term oncological outcomes in patients undergoing major abdominal cancer surgery.

Methods

The authors searched computerized databases and reference lists from inception to December 20, 2022. All studies that investigated the effects of perioperative RAA on long-term oncological outcomes following major abdominal cancer surgery were included. Using the inverse variance method with a random-effects model, hazard ratios (HR) and 95% confidence intervals (CI) were calculated.

Results

The systematic review included 51 retrospective studies, one prospective study, and three randomized controlled trials (RCTs), with a total of 95,046 patients. The results showed that perioperative RAA may improve long-term overall survival (HR: 0.85, 95% CI: 0.80 to 0.91, P = 0.00, I2 = 60.2%). However, there was no significant association between perioperative RAA and reduced cancer recurrence (HR: 0.98, 95% CI: 0.90 to 1.03, P = 0.31, I2 = 52.3%). When performing a pooled analysis of the data from the three RCTs, no statistically significant effect of RAA was found in either case.

Conclusion

The systematic review suggests perioperative RAA may improve long-term overall survival but does not appear to reduce cancer recurrence in patients undergoing major abdominal cancer surgery. The limited number of RCTs included in this study did not confirm this finding, highlighting the need for further RCTs to corroborate these results.

Morphine Analgesia, Cannabinoid Receptor 2, and Opioid Growth Factor Receptor Cancer Tissue Expression Improve Survival after Pancreatic Cancer Surgery

Pancreatic cancer (PDAC) has a poor prognosis despite surgical removal and adjuvant therapy. Additionally, the effects of postoperative analgesia with morphine and piritramide on survival among PDAC patients are unknown, as are their interactions with opioid/cannabinoid receptor gene expressions in PDAC tissue. Cancer-specific survival data for 71 PDAC patients who underwent radical surgery followed by postoperative analgesia with morphine (n = 48) or piritramide (n = 23) were therefore analyzed in conjunction with opioid/cannabinoid receptor gene expressions in the patients' tumors. Receptor gene expressions were determined using the quantitative real-time polymerase chain reaction. Patients receiving morphine had significantly longer cancer-specific survival (CSS) than those receiving piritramide postoperative analgesia (median 22.4 vs. 15 months; p = 0.038). This finding was supported by multivariate modelling (p < 0.001). The morphine and piritramide groups had similar morphine equipotent doses, receptor expression, and baseline characteristics. The opioid/cannabinoid receptor gene expression was analyzed in a group of 130 pancreatic cancer patients. Of the studied receptors, high cannabinoid receptor 2 (CB2) and opioid growth factor receptor (OGFR) gene expressions have a positive influence on the length of overall survival (OS; p = 0.029, resp. p = 0.01). Conversely, high delta opioid receptor gene expression shortened OS (p = 0.043). Multivariate modelling indicated that high CB2 and OGFR expression improved OS (HR = 0.538, p = 0.011, resp. HR = 0.435, p = 0.001), while high OPRD receptor expression shortened OS (HR = 2.264, p = 0.002). Morphine analgesia, CB2, and OGFR cancer tissue gene expression thus improved CSS resp. OS after radical PDAC surgery, whereas delta opioid receptor expression shortened OS.

Anaesthetic Techniques and Strategies: Do They Influence Oncological Outcomes?

BACKGROUND

With the global disease burden of cancer increasing, and with at least 60% of cancer patients requiring surgery and, hence, anaesthesia over their disease course, the question of whether anaesthetic and analgesia techniques during primary cancer resection surgery might influence long term oncological outcomes assumes high priority.

METHODS

We searched the available literature linking anaesthetic-analgesic techniques and strategies during tumour resection surgery to oncological outcomes and synthesised this narrative review, predominantly using studies published since 2019. Current evidence is presented around opioids, regional anaesthesia, propofol total intravenous anaesthesia (TIVA) and volatile anaesthesia, dexamethasone, dexmedetomidine, non-steroidal anti-inflammatory medications and beta-blockers.

CONCLUSIONS

The research base in onco-anaesthesia is expanding. There continue to be few sufficiently powered RCTs, which are necessary to confirm a causal link between any perioperative intervention and long-term oncologic outcome. In the absence of any convincing Level 1 recommending a change in practice, long-term oncologic benefit should not be part of the decision on choice of anaesthetic technique for tumour resection surgery.

Mu opioid receptor mRNA overexpression predicts poor prognosis among 18 common solid cancers: A pan-cancer analysis

Background

Opioids are widely used for patients with solid tumors during surgery and for cancer pain relief. We conducted a pan-cancer genomic analysis to investigate the prognostic features of Mu opioid receptor (MOR) mRNA expression across 18 primary solid cancers.

Methods

All the data of cancer with MOR mRNA were retrieved from cBioPortal for Cancer Genomics. Logistic regression was used to determine the associations between MOR mRNA expression and clinicopathological features. Log-rank test and Cox regression was used for survival analysis. Subgroup analysis and propensity score matching were also carried out.

Results

7,274 patients, including 1,112 patients with positive MOR mRNA expression, were included for data analyses. Positive MOR mRNA expression was associated with more advanced stage of T (adjusted Odds ratio [OR], 1.176; 95% confidence interval [CI], 1.022-1.354; P=0.024), M (adjusted OR, 1.548; 95% CI, 1.095-2.189; P=0.013) except N (adjusted OR, 1.145; 95% CI, 0.975-1.346; P=0.101), and worse prognosis for overall survival (Hazard ratio [HR] 1.347, 95% CI 1.200-1.512, P&lt;0.001), progression-free survival (HR 1.359, 95% CI 1.220-1.513, P&lt;0.001), disease-free survival (HR 1.269, 95% CI 1.016-1.585, P&lt;0.001) and disease-specific survival (HR 1.474, 95% CI 1.284-1.693, P&lt;0.001). Patients with positive MOR mRNA expression tended to be classified as tumor microenvironment immune types II, representing low PD-L1 and low CD8A expression.

Conclusion

MOR mRNA overexpression is associated with poor prognosis and poor response to PD-L1 therapy.

μ-opioid receptor agonist facilitates circulating tumor cell formation in bladder cancer via the MOR/AKT/Slug pathway: a comprehensive study including randomized controlled trial

BACKGROUND

μ-opioid receptor agonists (MORAs) are indispensable for analgesia in bladder cancer (BC) patients, both during surgery and for chronic pain treatment. Whether MORAs affect BC progression and metastasis remains largely unknown. This study focused on the effects of MORAs on the formation of circulating tumor cells (CTCs) in BC and aimed to provide potential therapeutic targets, which would retain the pain-relieving effects of MORAs in BC patients without sacrificing their long-term prognosis.

METHODS

Different preclinical models were used to identify the effects of MORAs on the progression of BC. A novel immunocapture microfluidic chip was utilized to analyze whether MORAs affected the number of CTCs in mouse models and clinical BC patients. Bioinformatic analyses, total transcriptome sequencing, and molecular biology methods were then used to investigate the underlying mechanisms in these models and in BC cell lines.

RESULTS

Mouse models of hematogenous metastasis and in situ BC demonstrated that tumor metastasis was significantly increased after MORA treatment. A significant increase in the number of mesenchymal and/or epithelial CTCs was detected after MORA treatment in both the mouse models and clinical trial patients. Mechanistically, MORAs facilitated the formation of CTCs by activating the MOR/PI3K/AKT/Slug signaling pathway, hereby promoting the epithelial-mesenchymal transition (EMT) of BC cells, as knockdown of MOR, Slug or blockade of PI3K inhibited the EMT process and CTC formation.

CONCLUSION

MORAs promoted BC metastasis by facilitating CTC formation. The EMT-CTC axis could be targeted for preventive measures during MORA treatment to inhibit the associated tumor metastasis or recurrence in BC patients.

Regional anesthesia did not improve postoperative long-term survival of tumor patients: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Experimental research and clinical trials have reported a positive effect of regional anesthesia (RA) on prognosis of cancers. We systematically reviewed the efficacy of RA on recurrence-free survival (RFS) and overall survival (OS) after oncology surgeries.

METHODS

PubMed, Cochrane library, and Embase were searched from inception to June 20, 2022 for RCTs in which any form of RA was initiated perioperatively. Time-to-event data (hazard ratio (HR)) were extracted independently and in duplicate. The primary outcome was the association of RA with RFS and OS, while the secondary outcomes included time to tumor progression, 5-year RFS, and 5-year OS.

RESULTS

Fifteen RCTs with 5981 participants were included. Compared to GA, RA has no positive effect on RFS (HR, - 0.02; 95% CI, - 0.11 to 0.07), OS (HR, - 0.03; 95% CI, - 0.28 to 0.23), time to tumor progression (0.11; 95% CI, - 0.33 to 0.55), 5-year RFS (risk ratio (RR), 1.24; 95% CI, 0.88 to 1.76)), and 5-year OS (RR, 1.11; 95% CI, 0.85 to 1.44). Subgroup analysis based on study design, patient characteristics and tumor types also showed no effect of RA on RFS or OS.

CONCLUSIONS

Our results demonstrated that there is no significant evidence supporting the role of RA in improving long-term survival after oncology surgeries.

Influence of opioid analgesia type on circulating tumor cells in open colorectal cancer surgery (POACC-1): study protocol for a prospective randomized multicenter controlled trial

BACKGROUND

Opioids and epidural analgesia are a mainstay of perioperative analgesia but their influence on cancer recurrence remains unclear. Based on retrospective data, we found that cancer recurrence following colorectal cancer surgery correlates with the number of circulating tumor cells (CTCs) in the early postoperative period. Also, morphine- but not piritramide-based postoperative analgesia increases the presence of CTCs and shortens cancer-specific survival. The influence of epidural analgesia on CTCs has not been studied yet.

METHODS

We intend to enroll 120 patients in four centers in this prospective randomized controlled trial. The study protocol has been approved by Ethics Committees in all participating centers. Patients undergoing radical open colorectal cancer surgery are randomized into epidural, morphine, and piritramide groups for perioperative analgesia. The primary outcome is the difference in the number of CTCs in the peripheral blood before surgery, on the second postoperative day, and 2-4 weeks after surgery. The number of CTCs is measured using molecular biology methods. Perioperative care is standardized, and relevant data is recorded. A secondary outcome, if feasible, would be the expression and activity of various receptor subtypes in cancer tissue. We intend to perform a 5-year follow-up with regard to metastasis development.

DISCUSSION

The mode of perioperative analgesia favorably affecting cancer recurrence would decrease morbidity/mortality. To identify such techniques, trials with long-term follow-up periods seem suboptimal. Given complex oncological therapeutic strategies, such trials likely disable the separation of perioperative analgesia effects from other factors. We believe that early postoperative CTCs presence/dynamics may serve as a sensitive marker of various perioperative interventions´ influences on cancer recurrence. Importantly, it is unbiased to the influence of long-term factors and minimally invasive. Analysis of opioid/cannabinoid receptor subtypes in cancer tissue would improve understanding of underlying mechanisms and promote personalization of treatment. We are not aware of any similar ongoing studies.

TRIAL REGISTRATION NUMBER

NCT03700411, registration date: October 3, 2018.

STUDY STATUS

recruiting.

Integrating mechanistic-based and classification-based concepts into perioperative pain management: an educational guide for acute pain physicians

Chronic pain begins with acute pain. Physicians tend to classify pain by duration (acute vs chronic) and mechanism (nociceptive, neuropathic and nociplastic). Although this taxonomy may facilitate diagnosis and documentation, such categories are to some degree arbitrary constructs, with significant overlap in terms of mechanisms and treatments. In clinical practice, there are myriad different definitions for chronic pain and a substantial portion of chronic pain involves mixed phenotypes. Classification of pain based on acuity and mechanisms informs management at all levels and constitutes a critical part of guidelines and treatment for chronic pain care. Yet specialty care is often siloed, with advances in understanding lagging years behind in some areas in which these developments should be at the forefront of clinical practice. For example, in perioperative pain management, enhanced recovery protocols are not standardized and tend to drive treatment without consideration of mechanisms, which in many cases may be incongruent with personalized medicine and mechanism-based treatment. In this educational document, we discuss mechanisms and classification of pain as it pertains to commonly performed surgical procedures. Our goal is to provide a clinical reference for the acute pain physician to facilitate pain management decision-making (both diagnosis and therapy) in the perioperative period.

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.

Association of Volatile Versus Intravenous Anesthesia With Prognosis After Nephrectomy for Renal Cell Carcinoma

BACKGROUND/AIM

A recent preclinical study reported that renal cell carcinoma was more susceptible to sevoflurane-mediated metastatic potentiation, compared to non-small cell lung cancer, suggesting that the effect of anesthetic agents on the metastatic potential varies according to cancer type. Based on this report, we conducted a retrospective cohort study to compare recurrence-free survival after nephrectomy, between renal cell carcinoma patients receiving volatile anesthesia and those receiving intravenous anesthesia.

PATIENTS AND METHODS

We reviewed the electronic medical records of patients who underwent partial or radical nephrectomy for renal cell carcinoma at the Seoul National University Hospital. Patients were divided into two groups according to whether volatile or intravenous anesthesia was used for nephrectomy. A total of 651 patients (582 in the volatile and 69 in the intravenous group) were enrolled in the study. Recurrence-free survival after nephrectomy was compared using Cox proportional hazards regression analysis with inverse probability of treatment weighting.

RESULTS

Cox regression analysis with inverse probability of treatment weighting revealed that volatile anesthesia had no impact on recurrence-free survival [hazard ratio (HR)=0.45; 95% confidence interval (CI)=0.07-2.85; p=0.398] or overall survival (HR=1.41; 95% CI=0.31-6.44; p=0.661).

CONCLUSION

We found no significant association between volatile anesthesia and poor outcomes after nephrectomy for renal cell carcinoma. Volatile anesthetic-promoted metastatic potentiation of renal cell carcinoma, shown in a preclinical study, does not seem to be translated in the clinical setting.

Immune Checkpoint Inhibitors and Opioids in Patients with Solid Tumours: Is Their Association Safe? A Systematic Literature Review

BACKGROUND

Immune checkpoint inhibitors (ICIs) represent one of the most effective treatments for patients with cancer. As their activity relies on host immune system reactivity, the role of concomitant medications such as corticosteroids and antibiotics has been extensively evaluated. Preclinical data suggest that opioids may influence the immune system.

METHODS

a systematic literature revision was performed using specific keywords on the major search engines. Two authors analysed all the studies and provided a selection of the following inclusion and exclusion criteria, respectively: 1. data collection of patients older than 18 years old affected by solid tumours; 2. description of ICIs efficacy in terms of PFS, OS, TTF, and ORR; 3. concomitant ICIs-opioids treatment and 1. language different from English; 2. not pertinent analyses.

RESULTS

523 studies were analysed, and 13 were selected and included in our series. A possible negative interaction between oral opioids and ICIs efficacy was observed. Most evidence was retrospective, and studies were heterogeneous.

CONCLUSIONS

Even if oral opioids seem to impact negatively on ICIs efficacy in cancer patients, to date there is not sufficient evidence to avoid their prescription in this population.

Effect of combined epidural-general anesthesia on long-term survival of patients with colorectal cancer: a meta-analysis of cohort studies

PURPOSE

This study aimed to analyze the long-term survival of patients with colorectal cancer after receiving combined epidural-general anesthesia (EGA) or general anesthesia (GA) alone.

METHODS

The PubMed, MEDLINE, Web of Science, Cochrane Library, and Embase databases were used to search for cohort studies that explored the differences between the effects of EGA and GA on overall survival (OS) and recurrence-free survival (RFS) of patients with colorectal cancer. The hazard ratios (HRs) and their 95% confidence intervals (95%CIs) were used as indicators to evaluate the strength of the effects and were pooled.

RESULTS

Nine studies were included in the meta-analysis. EGA improved the OS of patients with colorectal cancer compared with GA (HR = 0.904, 95%CI 0.871-0.938, P < 0.05). In the subgroup analysis, EGA was more protective for OS of patients with colon cancer than GA (HR = 0.840, 95%CI 0.732-0.963, P < 0.05), but not for OS of patients with rectal cancer (HR = 0.764, 95%CI 0.398-1.469, P > 0.05). Additionally, EGA could not further prolong RFS in patients with colorectal cancer (HR = 1.015, 95%CI 0.942-1.093, P > 0.05), which was the same in the subgroup analysis of patients with colon cancer (HR = 0.908, 95%CI 0.760-1.085, P > 0.05).

CONCLUSION

EGA could improve the OS of patients with colorectal cancer, especially those with colon cancer, but it could not improve the OS in the subgroup of patients with rectal cancer. This difference may be due to the immune protective function of the parasympathetic nerve innervating the intestinal tubes above the splenic flexure retained by EGA. Additionally, although EGA has a protective effect on RFS in patients with colorectal cancer, the difference was not significant.  The design of this analysis is registered and displayed in the PROSPERO database (CRD42021274864).

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.

Effect of epidural analgesia on cancer outcomes after gastric cancer resection: a single-centre cohort study in Taiwan

OBJECTIVE

To investigate the influence of epidural anaesthesia and analgesia (EA) on cancer recurrence and overall survival after surgery for gastric cancer.

STUDY DESIGN AND SETTING

A retrospective study which involved patients with stage I-III gastric cancer undergoing curative resection in a medical centre from January 2012 to December 2017 and followed up until December 2019 through electronic medical chart review. Patient demographics, anaesthetic and surgical characteristics and pathologic features were also gathered.

PRIMARY AND SECONDARY OUTCOME MEASURES

The effects of EA on postoperative cancer recurrence and overall survival were evaluated using proportional hazards regression models with inverse probability of treatment weighting (IPTW). Multivariable Cox regression analyses were conducted for sensitivity analysis as well.

RESULTS

Among the 413 patients with median follow-up of 38.5 months (IQR: 22.1-59.7), 66 (16.0%) received EA after gastric cancer surgery. EA was not associated with greater cancer recurrence (IPTW-adjusted HR: 0.55, 95% CI: 0.27 to 1.13, p=0.102) or cancer specific (IPTW- adjusted HR: 0.53, 95% CI: 0.27 to 1.04, p=0.07) and all-cause mortality (IPTW-adjusted HR: 0.65, 95% CI: 0.37 to 1.16, p=0.143) after gastric cancer resections. For sensitivity analysis, multivariable Cox regression analysis also generated non-significant EA effects on cancer recurrence and survival after surgery.

CONCLUSIONS

There was no significant association between EA and cancer recurrence or overall survival in patients with stage I-III gastric cancer receiving surgical resection of primary tumour. Prospective study should be considered to elucidate the relationship between EA and cancer outcomes after gastric cancer surgery.

Analgesic Effect of Ropivacaine Combined with Hydromorphone following Surgery for Mixed Hemorrhoids: A Pilot Study

Background

Postoperative pain is a major adverse effect of surgery for mixed hemorrhoids. We evaluated whether spinal anesthesia with ropivacaine and hydromorphone provided safe and effective analgesia after surgery for mixed hemorrhoids.

Methods

This single-center, double-blind pilot study included patients with mixed hemorrhoids who underwent a procedure for prolapse and hemorrhoids (PPH) and external hemorrhoidectomy under spinal anesthesia at Zhejiang Hospital, China (October 2020 to December 2020). Patients were randomized to a hydromorphone group (spinal anesthesia with 0.5% ropivacaine and 75 μg hydromorphone) or morphine group (spinal anesthesia with 0.5% ropivacaine and 150 μg morphine). Pain scores (numerical rating scale), incidences of vomiting and itching, and length of hospital stay (LoS) were recorded at 6, 12, 18, and 24 hours after surgery.

Results

The analysis included 40 patients in each group. Median (interquartile range) pain score in the hydromorphone group was higher than that in the morphine group at 12 hours (1 (0–2] vs. 0 (0–2), p=0.044) but not significantly different between groups at 6 hours (0 (0–1) vs. 0 (0-0) p=0.228), 18 hours (2 (2–3) vs. 2 (1–3) p=0.060) or 24 hours (2 (2–3) vs. 2 (1–3) p=0.081). The hydromorphone group had a lower incidence of pruritus than the morphine group (47.5% vs. 67.5%, p=0.018). There were no significant differences between groups in vomiting incidence or LoS.

Conclusion

In patients with mixed hemorrhoids, spinal anesthesia with ropivacaine/hydromorphone has a comparable analgesic effect and a lower incidence of pruritus during the first 24 hours after surgery than spinal anesthesia with ropivacaine/morphine.

Effects of Perioperative Epidural Analgesia on Cancer Recurrence and Survival

Surgical resection is the main curative avenue for various cancers. Unfortunately, cancer recurrence following surgery is commonly seen, and typically results in refractory disease and death. Currently, there is no consensus whether perioperative epidural analgesia (EA), including intraoperative and postoperative epidural analgesia, is beneficial or harmful on cancer recurrence and survival. Although controversial, mounting evidence from both clinical and animal studies have reported perioperative EA can improve cancer recurrence and survival via many aspects, including modulating the immune/inflammation response and reducing the use of anesthetic agents like inhalation anesthetics and opioids, which are independent risk factors for cancer recurrence. However, these results depend on the cancer types, cancer staging, patients age, opioids use, and the duration of follow-up. This review will summarize the effects of perioperative EA on the oncological outcomes of patients after cancer surgery.

Epidural Analgesia and Recurrence after Colorectal Cancer Surgery: A Danish Retrospective Registry-based Cohort Study

BACKGROUND

Surgery is the main curative treatment for colorectal cancer. Yet the immunologic and humoral response to surgery may facilitate progression of micro-metastases. It has been suggested that epidural analgesia preserves immune competency and prevents metastasis formation. Hence, the authors tested the hypothesis that epidural analgesia would result in less cancer recurrence after colorectal cancer surgery.

METHODS

The Danish Colorectal Cancer Group Database and the Danish Anesthesia Database were used to identify patients operated for colorectal cancer between 2004 and 2018 with no residual tumor tissue left after surgery. The exposure group was defined by preoperative insertion of an epidural catheter for analgesia. The primary outcome was colorectal cancer recurrence, and the secondary outcome was mortality. Recurrences were identified using a validated algorithm based on data from Danish health registries. Follow-up was until death or September 7, 2018. The authors used propensity score matching to adjust for potential preoperative confounders.

RESULTS

In the study population of 11,618 individuals, 3,496 (30.1%) had an epidural catheter inserted before surgery. The epidural analgesia group had higher proportions of total IV anesthesia, laparotomies, and rectal tumors, and epidural analgesia was most frequently used between 2009 and 2012. The propensity score-matched study cohort consisted of 2,980 individuals in each group with balanced baseline covariates. Median follow-up was 58 months (interquartile range, 29 to 86). Recurrence occurred in 567 (19.0%) individuals in the epidural analgesia group and 610 (20.5%) in the group without epidural analgesia. The authors found no association between epidural analgesia and recurrence (hazard ratio, 0.91; 95% CI, 0.82 to 1.02) or mortality (hazard ratio, 1.01; 95% CI, 0.92 to 1.10).

CONCLUSIONS

In colorectal cancer surgery, epidural analgesia was not statistically significantly associated with less cancer recurrence.

EDITOR’S PERSPECTIVE