Retrospective analysis of the effect of postoperative analgesia on survival in patients after laparoscopic resection of colorectal cancer

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.

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.

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.

Laparoscopic Radical Resection versus Routine Surgery for Colorectal Cancer

For patients with colorectal cancer, minimally invasive surgical methods, particularly laparoscopic methods, are now the preferred course of therapy. This research is performed to investigate the effects of laparoscopic radical resection on patients with colorectal cancer. A total of 100 colorectal cancer patients treated in our hospital from January 2017 to January 2019 were enrolled. The subjects were divided into observation (n = 50) and control (n = 50) groups and treated with laparoscopic surgery and laparotomy, respectively. As well as postoperative complications and survival rates, the levels of inflammatory substances, stress response, immunological function, and perioperative markers were compared between the two groups. There was no significant difference in the postoperative exhaust time between the two groups (P > 0.05). Compared with the control group, the observation group showed longer operation time, faster recovery of intestinal function, shorter hospital stay, and less intraoperative bleeding amount (P < 0.05). The serum contents of hs-CRP, TNF-α, IL-6, norepinephrine, adrenaline, and cortisol at 1 d, 3 d, and 5 d after surgery were significantly higher than before in both groups (P < 0.05). Moreover, the serum contents of hs-CRP, TNF-α, IL-6, norepinephrine, adrenaline, and cortisol in the observation group were significantly lower than that in the control group (P < 0.05). At 10 days following surgery, immune index levels had dramatically increased in both groups, with noticeably higher immune index levels in the observation group than in the control group (P < 0.05). There were no appreciable differences in the two groups' 2-year survival rates (P > 0.05), but the complication rate was much greater in the control group (P < 0.05). To sum up, after laparoscopic surgery, patients had fewer complications, shorter hospital stay, lower inflammatory factor expression, less stress response, better immune function, less trauma, faster recovery, and improved quality of life.

Association between enrollment in an enhanced recovery program for colorectal cancer surgery and long-term recurrence and survival

INTRODUCTION

Enhanced Recovery After Surgery (ERAS) programs have been shown to minimize the surgical inflammatory response in colorectal cancer. Our objective was to determine the association between an ERAS program for colorectal cancer surgery and oncologic recurrence and survival.

METHODS

A before-after intervention study was designed, including patients who underwent colorectal cancer surgery between November 2010 and March 2016. Cox hazard regression analysis was performed per cumulative year of follow-up to evaluate the association between ERAS program exposure and overall survival. Subgroup analysis was performed by cancer stage (low [I/II] vs. advanced [III/IV]).

RESULTS

In total, 646 patients were included, of which 339 were pre-ERAS and 307 were ERAS. Our overall median compliance rate with ERAS interventions was 90% (interquartile range: 85%-95%). Overall survival rates were higher in the ERAS group within the first 2 years after surgery (89.2% vs.  83.2%; p = 0.04). Multivariable analysis revealed that the ERAS enrollment was associated with a significantly lower risk in 5-year oncologic recurrence (adjusted hazard ratio [aHR]: 0.55; 95% confidence interval [CI]: 0.33-0.94; p = 0.03) and higher 3-year survival (aHR: 0.55; 95% CI: 0.33-0.93; p = 0.03) among patients with advanced cancer stage compared to pre-ERAS counterparts.

CONCLUSIONS

Patients with advanced colorectal cancer were less likely to suffer oncologic recurrence when managed during the ERAS period.

Direct Cytotoxic and Indirect, Immune-Mediated Effects of Local Anesthetics Against Cancer

Local anesthetics are frequently employed during surgery in order to control peri- and postoperative pain. Retrospective studies have revealed an unexpected correlation between increased long-term survival and the use of local anesthetics during oncological surgery. This effect of local anesthetics might rely on direct cytotoxic effects on malignant cells or on indirect, immune-mediated effects. It is tempting to speculate, yet needs to be formally proven, that the combination of local anesthetics with oncological surgery and conventional anticancer therapy would offer an opportunity to control residual cancer cells. This review summarizes findings from fundamental research together with clinical data on the use of local anesthetics as anticancer standalone drugs or their combination with conventional treatments. We suggest that a better comprehension of the anticancer effects of local anesthetics at the preclinical and clinical levels may broadly improve the surgical treatment of cancer.

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

Anesthesia Techniques and Long-Term Oncological Outcomes

Despite advances in cancer treatments, surgery remains one of the most important therapies for solid tumors. Unfortunately, surgery promotes angiogenesis, shedding of cancer cells into the circulation and suppresses anti-tumor immunity. Together this increases the risk of tumor metastasis, accelerated growth of pre-existing micro-metastasis and cancer recurrence. It was theorized that regional anesthesia could influence long-term outcomes after cancer surgery, however new clinical evidence demonstrates that the anesthesia technique has little influence in oncologic outcomes. Several randomized controlled trials are in progress and may provide a better understanding on how volatile and intravenous hypnotics impact cancer progression. The purpose of this review is to summarize the effect of the anesthesia techniques on the immune system and tumor microenvironment (TME) as well as to summarize the clinical evidence of anesthesia techniques on cancer outcomes.

Anesthetic care influences long-term outcomes: What is the evidence?

Despite advances in cancer therapy surgery remains one of the most important treatments for solid tumors; however, even with the development of better and less invasive surgical techniques, surgery is characterized by the increased risk of tumor metastasis, accelerated growth of pre-existing micrometastasis and cancer recurrence. Total intravenous anesthesia (TIVA) and regional anesthesia have been proposed to improve long-term outcomes after cancer surgery by different mechanisms, including attenuation of the neuroendocrine response, immunosuppression, decreased opioid requirements (opioids promote angiogenesis and tumor growth) and avoidance of volatile inhalational agents. Much of the data that support these ideas originate from laboratory studies, while there is no clear consensus from the retrospective cohort studies to date. Several randomized controlled trials (RCTs) are in progress and may provide a better understanding regarding the role of the anesthesiologist in cancer surgery. The purpose of this review is to summarize the experimental and human data regarding the effect of anesthesia agents and anesthesia techniques on cancer outcomes.

Peridural Anesthesia and Cancer-Related Survival after Surgery for Pancreatic Cancer-A Retrospective Cohort Study

Background: In patients with prostatic and breast cancer the application of peridural anesthesia (PDA) showed a beneficial effect on prognosis. This was explained by reduced requirements for general anesthetics and perioperative opioids as well as a lower perioperative stress level. The impact of PDA in patients with more aggressive types of cancer has not been completely elucidated. Here, we analyzed the prognostic influence of PDA on overall survival after surgery as primary in patients that underwent radical resection of pancreatic adenocarcinoma. Methods: Records of 98 consecutive patients were reviewed. In 70 of these cases PDA was applied. Patient characteristics such as demographics, TNM stage, and operative data were retrospectively collected from medical records and analyzed. Survival data were analyzed by Cox’s proportional hazard regression model. Results: Overall, no significant prognostic influence of PDA on recurrence or overall survival (p = 0.762, Hazard Ratio [HR] 0.884, 95% confidence interval [CI] 0.398–1.961) was found. However, there was a trend towards a longer overall survival (p = 0.069, HR 0.394, 95% CI 0.144–1.078) associated with PDA in a subgroup of patients with better differentiation of pancreatic adenocarcinoma. Conclusion: The observation of longer survival associated with PDA in our subgroup of patients with better-differentiated pancreatic carcinomas is in line with previous reports on various other less aggressive tumor entities. Our results indicate that PDA might improve the oncological outcome of patients with pancreatic adenocarcinoma.

Epidural analgesia and mortality after colorectal cancer surgery: A retrospective cohort study

Background

Epidural analgesia (EA) has been the standard of care after major abdominal surgery for many years. This study aimed to correlate EA with postoperative complications, short- and long-term mortality in patients with and without EA after open surgery (OS) and minimally invasive surgery (MIS) for colorectal cancer.

Methods

Patient, clinical and outcome data were obtained from the Swedish Colorectal Cancer Registry and the Swedish Perioperative Registry. All adult patients diagnosed with colorectal cancer without metastases who underwent elective curative MIS or OS for colorectal cancer between January 2016 and December 2018 and who had data recorded in both registries, were included in the study. Data were analyzed for OS and MIS procedures separately. A Poisson regression model was used to investigate the association between EA and the outcomes of interest.

Results

Five thousand seven hundred sixty-two patients were included in the study, 2712 in the MIS and 3050 patients in the OS group. After adjusting for patient specific and clinically relevant variables in the regression model, no statistically significant difference in risk for complications; 30-day, 90-day, and up to 3-year mortality following either MIS or OS could be detected between the EA+ and EA-cohorts.

Conclusions

In this large study cohort, EA as part of the comprehensive care provided was not associated with a reduction in postoperative complications risk or improved 30-day, 90-day, or 3-year survival after MIS or OS for colorectal cancer.

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No reduction in postoperative complications with epidural analgesia.

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No reduction in short-term mortality with epidural analgesia after colorectal surgery.

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No reduction in long-term mortality with epidural analgesia in colorectal cancer.

Anesthetic technique and cancer surgery outcomes

PURPOSE OF REVIEW

Surgery remains integral to treating solid cancers. However, the surgical stress response, characterized by physiologic perturbation of the adrenergic, inflammatory, and immune systems, may promote procancerous pathways. Anesthetic technique per se may attenuate/enhance these pathways and thereby could be implicated in long-term cancer outcomes.

RECENT FINDINGS

To date, clinical studies have predominantly been retrospective and underpowered and, thus limit meaningful conclusions. More recently, prospective studies of regional anesthesia for breast and colorectal cancer surgery have failed to demonstrate long-term cancer outcome benefit. However, based on the consistent observation of protumorigenic effects of surgical stress and that of volatile anesthesia in preclinical studies, supported by in vivo models of tumor progression and metastasis, we await robust prospective clinical studies exploring the role of propofol-based total intravenous anesthesia (cf. inhalational volatiles). Additionally, anti-adrenergic/anti-inflammatory adjuncts, such as lidocaine, nonsteroidal anti-inflammatory drugs and the anti-adrenergic propranolol warrant ongoing research.

SUMMARY

The biologic perturbation of the perioperative period, compounded by the effects of anesthetic agents, renders patients with cancer particularly vulnerable to enhanced viability of minimal residual disease, with long-term outcome consequences. However, low level and often conflicting clinical evidence equipoise currently exists with regards to optimal oncoanesthesia techniques. Large, prospective, randomized control trials are urgently needed to inform evidence-based clinical practice guidelines.

The role of regional anaesthesia in the emerging subspecialty of onco-anaesthesia: a state-of-the-art review

Cancer accounts for millions of deaths globally each year, predominantly due to recurrence and metastatic disease. The majority of patients with primary solid organ cancers require surgery, however, some degree of tumour dissemination related to surgery is inevitable. The surgical stress response and associated immunosuppression, pain, inflammation, tissue hypoxia and angiogenesis have all been implicated in promoting tumour survival, proliferation and recurrence. Regional anaesthesia was hypothesised to reduce the surgical stress response and immunosuppression, minimise the need for volatile anaesthesia and reduce pain and opioid requirements, thus mitigating pro-tumour pathways associated with the peri-operative period and improving long-term oncological outcomes. While some retrospective studies suggested an association between regional anaesthesia and reduced cancer recurrence, the first large randomised controlled trial on the effect of anaesthetic technique on cancer outcome found no significant difference between paravertebral regional anaesthesia and volatile anaesthesia with opioid analgesia in patients undergoing breast cancer surgery. Randomised controlled trials on the long-term oncological outcomes of regional anaesthesia in other tumour types are ongoing. The focus on how peri-operative interventions, especially regional anaesthesia, during cancer resection surgery, may enhance short-term recovery and perhaps influence long-term outcome has spawned the global emergence of the subspecialty of onco-anaesthesia. This review aims to discuss the most recent evidence on the use of regional anaesthesia in cancer surgery and the significance of its role in onco-anaesthesia.

Study on the prevention of infection in terminal cancer patients applying epidural analgesia by adding cefazolin to anesthetics: a randomized controlled trial

OBJECTIVE

To observe the antibacterial effect of adding cefazolin into anesthetics in patients with terminal cancer undergoing long-term epidural analgesia.

METHODS

Patients undergoing epidural analgesia with terminal cancer were randomly divided into two groups: the conventional drug group (group C) and the cefazolin group (group G). Both groups were given levobupivacaine and morphine, while cefazolin was added to group G. The mean arterial pressure (MAP), heart rate (HR), respiratory rates (R), visual analogue scale (VAS) scores, satisfaction and complications of patients in the two groups were observed. 3 ml of the used analgesic was taken for bacterial culture when replacing the new analgesic case.

RESULTS

HR, MAP, R, VAS scores, dosages of morphine, satisfaction of the analgesic and the complications were not significantly different between the two groups (P > 0.05). The overall satisfaction of patients in group G was significantly higher than that in group C (P < 0.05). One patient's anesthetics in group C were infected with colibacillus. Four patients in group C got infected in their epidural puncture sites. There was no infection in group G (P < 0.05).

CONCLUSION

Adding cefazolin to local anesthetics could effectively prevent bacterial infection and ensured the safety of epidural analgesia for patients with terminal cancer.

Anesthesia Options and the Recurrence of Cancer: What We Know so Far?

Surgery is a critical period in the survival of patients with cancer. While resective surgery of primary tumors has shown to prolong the life of these patients, it can also promote mechanisms associated with metastatic progression. During surgery, patients require general and sometimes local anesthetics that also modulate mechanisms that can favor or reduce metastasis. In this narrative review, we summarized the evidence about the impact of local, regional and general anesthesia on metastatic mechanisms and the survival of patients. The available evidence suggests that cancer recurrence is not significantly impacted by neither regional anesthesia nor volatile or total intravenous anesthesia.

Influence of perioperative anaesthetic and analgesic interventions on oncological outcomes: a narrative review

Surgery is an important treatment modality for the majority of solid organ cancers. Unfortunately, cancer recurrence following surgery of curative intent is common, and typically results in refractory disease and patient death. Surgery and other perioperative interventions induce a biological state conducive to the survival and growth of residual cancer cells released from the primary tumour intraoperatively, which may influence the risk of a subsequent metastatic disease. Evidence is accumulating that anaesthetic and analgesic interventions could affect many of these pathophysiological processes, influencing risk of cancer recurrence in either a beneficial or detrimental way. Much of this evidence is from experimental in vitro and in vivo models, with clinical evidence largely limited to retrospective observational studies or post hoc analysis of RCTs originally designed to evaluate non-cancer outcomes. This narrative review summarises the current state of evidence regarding the potential effect of perioperative anaesthetic and analgesic interventions on cancer biology and clinical outcomes. Proving a causal link will require data from prospective RCTs with oncological outcomes as primary endpoints, a number of which will report in the coming years. Until then, there is insufficient evidence to recommend any particular anaesthetic or analgesic technique for patients undergoing tumour resection surgery on the basis that it might alter the risk of recurrence or metastasis.

Guidelines for Perioperative Care in Elective Colorectal Surgery: Enhanced Recovery After Surgery (ERAS®) Society Recommendations: 2018

BACKGROUND

This is the fourth updated Enhanced Recovery After Surgery (ERAS®) Society guideline presenting a consensus for optimal perioperative care in colorectal surgery and providing graded recommendations for each ERAS item within the ERAS® protocol.

METHODS

A wide database search on English literature publications was performed. Studies on each item within the protocol were selected with particular attention paid to meta-analyses, randomised controlled trials and large prospective cohorts and examined, reviewed and graded according to Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system.

RESULTS

All recommendations on ERAS® protocol items are based on best available evidence; good-quality trials; meta-analyses of good-quality trials; or large cohort studies. The level of evidence for the use of each item is presented accordingly.

CONCLUSIONS

The evidence base and recommendation for items within the multimodal perioperative care pathway are presented by the ERAS® Society in this comprehensive consensus review.

Immune function after major surgical interventions: the effect of postoperative pain treatment

INTRODUCTION

Impaired immune function during the perioperative period may be associated with worse short- and long-term outcomes. Morphine is considered a major contributor to immune modulation.

PATIENTS AND METHODS

We performed a pilot study to investigate postoperative immune function by analyzing peripheral blood mononuclear cells' functionality and cytokine production in 16 patients undergoing major abdominal surgery. All patients were treated with intravenous (i.v.) patient-controlled analgesia with morphine and continuous wound infusion with ropivacaine+methylprednisolone for 24 hours. After 24 hours, patients were randomized into two groups, one continuing intrawound infusion and the other receiving only i.v. analgesia. We evaluated lymphoproliferation and cytokine production by peripheral blood mononuclear cells at the end of surgery and at 24 and 48 hours postoperatively.

RESULTS

A significant reduction in TNF-α, IL-2, IFN-γ and lymphoproliferation was observed immediately after surgery, indicating impaired cell-mediated immunity. TNF-α and IFN-γ remained suppressed up to 48 hours after surgery, while a trend to normalization was observed for IL-2 and lymphoproliferation, irrespective of the treatment group. A significant inverse correlation was present between age and morphine and between age and lymphoproliferation. No negative correlation was present between morphine and cytokine production. We did not find any differences within the two groups between 24 and 48 hours in terms of morphine consumption and immune responses.

CONCLUSION

A relevant depression of cell-mediated immunity is associated with major surgery and persists despite optimal analgesia. Even though morphine may participate in immunosuppression, we did not retrieve any dose-related effect.

What Can Regional Anesthesiology and Acute Pain Medicine Learn from "Big Data"?

Demonstrating value added to patients' experience through regional anesthesiology and acute pain medicine is critical. Evidence supporting improved outcomes can be derived from prospective studies or retrospective cohort studies. Population-based studies relying on existing clinical and administrative databases are helpful when an outcome is rare and detecting a change would require studying large numbers of patients. This article discusses the effect of regional anesthesiology and acute pain medicine interventions on mortality and morbidity, infection rate, cancer recurrence, inpatient falls, local anesthetic systemic toxicity, persistent postsurgical pain, and health care costs.

The effect of neuraxial anesthesia on cancer recurrence and survival after cancer surgery: an updated meta-analysis

Several animal and observational studies have evaluated the effects of neuraxial anesthesia on the recurrence and survival of cancer surgery; studies reported benefit, whereas others did not. To provide further evidence that neuraxial anesthesia(combined with or without general anesthesia (GA))may be associated with reduced cancer recurrence and long-term survival after cancer surgery, we conducted this meta-analysis. A total of 21 studies were identified and analyzed, based on searches conducted using PubMed, Web of Science, EMBASE database and the Cochrane Database of Systematic Reviews. After data abstraction, adjusted hazard ratios (HR) with 95% confidence intervals (CIs) were used to assess the impact of neuraxial anesthesia (combined with or without GA) and GA on oncological outcomes after cancer surgery. For overall survival (OS), a potential association between neuraxial anesthesia and improved OS (HR 0.853, CI 0.741-0.981, P = 0.026, the random-effects model) was observed compared with GA. Specifically, we found a positive association between neuraxial anesthesia and improved OS in colorectal cancer (HR 0.653, CI 0.430-0.991, P = 0.045, the random-effects model). For recurrence-free survival (RFS), a significant association between neuraxial anesthesia and improved RFS (HR 0.846, CI 0.718-0.998, P = 0.047, the random-effects model) was detected compared with GA. Our meta-analysis suggests that neuraxial anesthesia may be associated with improved OS in patients with cancer surgery, especially for those patients with colorectal cancer. It also supports a potential association between neuraxial anesthesia and a reduced risk of cancer recurrence. More prospective studies are needed to elucidate whether the association between neuraxial use and survival is causative.

Association Between Acute Pain and Hemodynamic Parameters in a Postoperative Surgical Intensive Care Unit

I conducted a prospective repeated-measure study in the general surgery intensive care unit to investigate the associations among acute postoperative pain, analgesic therapy, and hemodynamic parameters. I selected 33 patients and recorded 84 episodes of pain. I measured intensity of pain and hemodynamic parameters after patients were transferred from the postanesthesia care unit to the general surgery intensive care unit, immediately before analgesic therapy and at 15, 30, and 45 minutes after analgesic therapy. Acute pain increased systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP); pulse rate (PR); and arterial oxygen saturation. Fifteen minutes after analgesic therapy, SBP and PR decreased, and DBP, MAP, and oxygen saturation increased. Thirty minutes after therapy, SBP, MAP, and PR decreased, and DBP and oxygen saturation increased. Forty-five minutes after therapy, SBP, MAP, and PR decreased, and DBP and oxygen saturation increased. I saw no significant hemodynamic parameter changes during postoperative episodes of pain.

Anesthetic technique and cancer recurrence in oncologic surgery: unraveling the puzzle

Surgery/anesthetic technique-stimulated immunosuppression in the perioperative period might cause an increase in cancer-related mortality. Whether anesthetic technique can affect the outcomes of cancer patients remains inconclusive. This review discusses data from the available literature on anesthetic techniques applied in oncologic surgery, the long-term outcomes of anesthetic technique, and their relation to survival and cancer recurrence. Searches of the PubMed database up to June 30, 2016, were conducted to identify publications with the terms "anesthetic technique and cancer recurrence," "regional anesthesia and cancer recurrence," "local anesthesia and cancer recurrence," "anesthetic technique and immunosuppression," and "anesthetic technique and oncologic surgery." Surgery/anesthesia-stimulated activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS) provides immunosuppression through several soluble factors. Volatile anesthetics and opioids suppress cell-mediated immunity (CMI) and promote the proliferation of cancer cells and angiogenesis, whereas propofol does not suppress CMI and inhibits tumor angiogenesis. Regional anesthesia (RA) protects CMI and diminishes the surgical neuroendocrine stress response by blocking afferent neural transmission that stimulates the HPA axis and SNS, decreasing the requirement for opioids and volatile anesthetics and thereby decreasing cancer recurrence. Preclinical and retrospective studies highlight a potential benefit of anesthetic technique in reducing cancer-related mortality and recurrence by attenuating immunosuppression following surgical treatment in patients with specific types of cancer. Several well-planned, prospective, randomized controlled trials (RCTs) are underway that may provide more conclusive and definitive results regarding the benefits of anesthetic technique on survival in oncologic surgery.

Perioperative Anesthesia Care and Tumor Progression

This narrative review discusses the most recent up-to-date findings focused on the currently available "best clinical practice" regarding perioperative anesthesia care bundle factors and their effect on tumor progression. The main objective is to critically appraise the current literature on local anesthetics, regional outcome studies, opioids, and nonsteroidal anti-inflammatory drugs (NSAIDs) and their ability to decrease recurrence in patients undergoing cancer surgery. A brief discussion of additional topical perioperative factors relevant to the anesthesiologist including volatile and intravenous anesthetics, perioperative stress and anxiety, nutrition, and immune stimulation is included. The results of several recently published systematic reviews looking at the association between cancer recurrences and regional anesthesia have yielded inconclusive data and provide insufficient evidence regarding a definitive benefit of regional anesthesia. Basic science data suggests an anti tumor effect induced by local anesthetics. New refined animal models show that opioids can safely be used for perioperative pain management. Preliminary evidence suggests that NSAIDs should be an essential part of multimodal analgesia. Volatile anesthetics have been shown to increase tumor formation, whereas preclinical and emerging clinical data from propofol indicate tumor protective qualities. The perioperative period in the cancer patient represents a unique environment where surgically mediated stress response leads to immune suppression. Regional anesthesia techniques when indicated in combination with multimodal analgesia that include NSAIDs, opioids, and local anesthetics to prevent the pathophysiologic effects of pain and neuroendocrine stress response should be viewed as an essential part of balanced anesthesia.

The Relationship Between Regional Anesthesia and Cancer: A Metaanalysis

BACKGROUND

Some studies have suggested using epidural analgesia after cancer surgery to reduce metastasis. This article examines the relationship between regional anesthesia (RA) and cancer metastasis in an array of cancers.

METHODS

We conducted a review of the literature using PubMed and included 67,577 patients across 28 studies in a metaanalysis, evaluating the hazard ratios (HRs) of overall survival, recurrence-free survival, and biochemical recurrence-free survival.

RESULTS

We found no benefit to RA as it relates to cancer. The HR was 0.92 for overall survival, 1.06 for recurrence-free survival, and 1.05 for biochemical recurrence-free survival. Despite the overall analysis showing no benefit, we found some benefit when we evaluated only the randomized trials. However, we found no significant benefit of RA when we evaluated the cancers (gastrointestinal, prostate, breast, and ovarian) individually.

CONCLUSION

This metaanalysis shows that RA has no overall survival, recurrence-free survival, or biochemical recurrence-free survival benefit. However, some individual studies have shown significant benefit in terms of cancer recurrence. Further, RA reduces the use of opioids, which has led to some secondary benefits. Further studies are needed to establish the benefits of RA as it relates to cancer.

Protocol for a multicentre, prospective, observational cohort study of variation in practice in perioperative analgesic strategies in elective laparoscopic colorectal surgery: the LapCoGesic Study

INTRODUCTION

Laparoscopic surgery combined with enhanced recovery programmes has become the gold standard in the elective management of colorectal disease. However, there is no consensus with regard to the optimal perioperative analgesic regime in this cohort of patients, with a number of options available, including thoracic epidural spinal analgesia, patient-controlled analgesia, subcutaneous and/or intraperitoneal local anaesthetics, local anaesthetic wound infiltration catheters and transversus abdominis plane blocks. This study aims to explore any differences in analgesic strategies employed across the North East of England and to assess whether any variation in practice has an impact on clinical outcomes.

METHODS AND ANALYSIS

All North East Colorectal units will be recruited for participation by the Northern Surgical Trainees Research Association (NoSTRA). Data will be collected over a consecutive 2-month period. Outcome measures will include postoperative pain score, postoperative opioid analgesic use and side effects, length of stay, 30-day complication rates, 30-day reoperative rates and 30-day readmission rates.

ETHICS AND DISSEMINATION

Ethical approval for this study has been granted by the National Research Ethics Service. The protocol will be disseminated through NoSTRA. Individual unit data will be presented at local meetings. Overall collective data will be published in peer-reviewed journals and presented at relevant surgical meetings.

The Effects of Perioperative Regional Anesthesia and Analgesia on Cancer Recurrence and Survival After Oncology Surgery: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Potentially, perioperative regional anesthesia and analgesia (RA) could influence the outcomes of patients with cancer. The aim of this systematic review and meta-analysis was to evaluate the effects of perioperative RA on survival and cancer recurrence after oncologic surgery.

METHODS

The authors searched computerized databases (from inception to December 2014) and reference lists and considered all studies comparing the effects of RA on cancer recurrence or overall survival with that of general anesthesia (GA). Risk estimates were pooled to determine the effects of RA on risks of cancer recurrence and mortality. Twenty eligible studies were included.

RESULTS

Perioperative RA use was associated with improved overall survival (Hazard ratio [HR] = 0.84, 95% CI, 0.75 - 0.94; I =41%), but not with reduced cancer recurrence (HR=0.91, 95% CI, 0.70 - 1.18; I=83%).

CONCLUSIONS

Our meta-analysis suggests that RA may improve overall survival but not reduce cancer recurrence after oncologic surgery.

Effects of Postoperative Pain Management on Immune Function After Laparoscopic Resection of Colorectal Cancer: A Randomized Study

There has been a rising interest in the possible association between perioperative opioid use and postoperative outcomes in cancer patients. Continuous surgical wound infiltration with local anesthetics is a nonopioid analgesic technique that can be used as a postoperative pain management alternative to opioid-based intravenous patient-controlled analgesia (IV PCA). The aim of this study was to compare the effects of an opioid-based analgesic regimen versus a local anesthetic wound infiltration-based analgesic regimen on immune modulation and short-term cancer recurrence or metastasis in patients undergoing laparoscopic resection of colorectal cancer.Sixty patients undergoing laparoscopic resection of colorectal cancer were randomly assigned to either the opioid group or the ON-Q group. For postoperative analgesia during the first 48 hours, the opioid group (n = 30) received fentanyl via IV PCA, whereas the ON-Q group (n = 30) received continuous wound infiltration of 0.5% ropivacaine with an ON-Q pump and tramadol via IV PCA. Pethidine for the opioid group and ketorolac or propacetamol for the ON-Q group were used as rescue analgesics. Anesthesia was induced and maintained with propofol and remifentanil. The primary outcome was postoperative immune function assessed by natural killer cell cytotoxicity (NKCC) and interleukin-2. Secondary outcomes were postoperative complications, cancer recurrence, or metastasis within 1 year after surgery, and postoperative inflammatory responses measured by white blood cell count, neutrophil percentage, and C-reactive protein. Immune function and inflammatory responses were measured before surgery and 24 and 48 hours after surgery.Fifty-nine patients completed the study. In the circumstance of similar pain control efficacy between the opioid group and the ON-Q group, postoperative NKCC and interleukin-2 levels did not differ between the 2 groups. The incidence of postoperative complications and recurrence or metastasis within 1 year after surgery was comparable between the groups. Postoperative inflammatory responses were also similar between the groups.When compared with ropivacaine wound infiltration-based analgesia, fentanyl-based analgesia did not further decrease NKCC or affect short-term cancer recurrence or metastasis. Thus, a fentanyl-based analgesic regimen and a ropivacaine wound infiltration-based analgesic regimen can both be used for postoperative pain management in laparoscopic resection of colorectal cancer.

Effects of anaesthesia on proliferation, invasion and apoptosis of LoVo colon cancer cells in vitro

Tumour cell proliferation, invasion and apoptosis are crucial steps in tumour metastasis. We evaluated the effect of serum from patients undergoing colon cancer surgery receiving thoracic epidural and propofol anaesthesia on colon cancer cell biology. Patients were randomly assigned to receive propofol anaesthesia with a concomitant thoracic epidural (PEA, n = 20) or sevoflurane anaesthesia with opioid analgesia (SGA, n = 20). Venous blood was obtained before induction of anaesthesia and 24 hours postoperatively. The LoVo colon cancer cells were cultured with patient serum from both groups and the effects on proliferation, invasion and apoptosis were measured. Twenty-four hours after surgery, the absorbance value of LoVo cells at 10% serum concentration from PEA was decreased when compared with SGA (0.302 (0.026) vs 0.391 (0.066), p = 0.005). The inhibitory rate of LoVo cells at 10% serum concentration from PEA was higher than that from SGA (p = 0.004) 24 h after surgery. The number of invasive LoVo cells at 10% serum concentration from PEA was reduced when compared with SGA (44 (4) vs 62 (4), p < 0.001). Exposure of LoVo cells to postoperative serum from patients receiving PEA led to a higher luminescence ratio (apoptosis) than those receiving SGA (0.36 (0.04) vs 0.27 (0.05), p < 0.001). Serum from patients receiving PEA for colon cancer surgery inhibited proliferation and invasion of LoVo cells and induced apoptosis in vitro more than that from patients receiving SGA. Anaesthetic technique might influence the serum milieu in a way that affects cancer cell biology and, thereby, tumour metastastasis.

Effect of mu Agonists on Long-Term Survival and Recurrence in Nonsmall Cell Lung Cancer Patients

Opioids are widely used for postoperative analgesia. Morphine may have an effect on cell replication, migration, and cancer recurrence. However, the association of postoperative mu agonists with outcome of nonsmall cell lung cancer (NSCLC) patients has not been fully investigated.We retrospectively evaluated the impact of postoperative mu agonists on overall survival (OS) and disease-free survival (DFS) in early stage NSCLC patients. Patients and relevant medical information were selected from the Bio-Bank of Shandong Provincial Hospital. Difference of clinicopathologic information in postoperative mu agonists group and no mu agonists group was analyzed by χ test. Univariate and multivariate Cox regression analysis were conducted and represented as hazards ratio and 95% confidence interval form. The primary endpoint was OS and secondary endpoint was DFS.This retrospective study included 984 consecutive NSCLC patients who underwent surgery between January 2006 and December 2011. No significant difference existed between postoperative mu agonists usage group and no mu agonists usage group in clinicopathologic information except operation type (P = 0.041). Postoperative mu agonists usage was related to shorter OS (HR 1.514, 95% CI 1.197-1.916, P = 0.001) and shorter DFS (HR 1.415, 95% CI 1.123-1.781, P = 0.003) in the multivariate Cox regression model. For the patients who received postoperative chemotherapy or radiotherapy postoperative mu agonists also predict shorter survival (HR 1.437, 95% CI 1.041-1.982, P = 0.027). Subgroup analysis showed that administration of postoperative mu agonists was related to shorter OS, especially in males, more smoking, poor differential degree, bilobectomy or pneumonectomy, and stage III subgroup, respectively.Administration of postoperative mu agonists was related to shorter OS and DFS for the NSCLC patients who underwent surgery.

The effects of anaesthetics on postoperative physiological reactions: a meta-analysis

This study aimed to systematically investigate the effects of different anaesthetics on postoperative physiological reactions compared with placebo. The literature search was conducted using three databases: PubMed, EMBASE, and the Cochrane Library. Studies published from January 1990 to January 2015 were screened. The language was restricted to English. Heterogeneity was analyzed by the Q test and I(2) statistic. A fixed-effect model was used for homogenous data and a random-effects model for heterogeneous data. The odds ratio (OR) and 95% confidence interval (CI) were calculated to monitor the incidences of overall adverse events, arterial blood pressure, and cardiac abnormalities. Sensitivity analysis was performed to estimate the strength of the meta-analysis, and publication bias was analyzed using Egger's test. A total of 24 articles were included in this meta-analysis. There were 1,810 and 1,806 cases in the anaesthetic group and the placebo group, respectively. The incidence of overall adverse events was significantly lower in the anaesthetic group compared with the placebo group (OR = 0.57; 95% CI, 0.38-0.84). No publication bias was observed, and no inverse estimates were calculated using sensitivity analysis. There was no significant difference for the incidence of arterial blood pressure (OR = 4.62; 95% CI, 0.90-23.70) and cardiac abnormalities (OR = 1.18; 95% CI, 0.53-2.63) between the two groups. Although the incidence of overall adverse events was decreased in the anaesthetic group, it is impossible to determine whether the use of anaesthetics during surgical operation has a protective effect on postoperative physiological reactions.

Quality of Life and Pain Control following Laparoscopic Retroperitoneal Lymph Node Dissection in Early-stage Nonseminoma

Aims and Background

To evaluate postoperative pain (PoP) and quality of life (QoL) in patients undergoing open (O-) or laparoscopic (L-) retroperitoneal lymph node dissection (RPLND) for clinical stage I (CS I) and normal markers CS IIA nonseminomatous germ cell tumors.

Methods

Since March 2010, a prospective nonrandomized trial evaluated dynamic and rest (R) numeric pain scale (NPS) following patient-controlled analgesia and baseline (T0), 3-month (T3), and 6-month (T6) QoL status assessed by Functional Assessment of Cancer Therapy-General (FACT-G) questionnaire and the Italian-validated Functional Assessment of Chronic Illness Therapy (FACT-T-SG) at T6. Secondary endpoints included length of hospital stay (LHS), interval to recovery (ItR), complications, and oncologic outcomes.

Results

In March 2012, 69 (64 CS I) patients were enrolled. Five patients only chose O-RPLND. The PoP and complete QoL data are available in 41 and 56 patients, respectively. The R-NPS significantly improved in days 1-2 vs day 0 (p<0.0008). The FACT-G scores improved from baseline: the emotional well-being scale was the most relevant at T3 (+7.0, p = 0.0001) and T6 (+6.9, p = 0.0002). The FACT-TS-G indicated high satisfaction levels. Median LHS and ItR were 3 and 15 days. Six complications required an intervention. Nodal metastases were found in 14 (20.3%) patients. Following a median follow-up of 36 months, 6 (8.9%) patients relapsed (2/12 among pN+), and 8 patients (11.9%) underwent chemotherapy. All patients maintained antegrade ejaculation and are alive and disease-free.

Conclusions

Almost all patients chose L-RPLND, which is associated with a rapid improvement of postoperative pain; QoL scores improved up to 6 months. The L-RPLND may be considered as an alternative only when performed in highly experienced centers.

Optimal analgesia during major open and laparoscopic abdominal surgery

Optimal analgesia is a key element of enhanced recovery after surgery (ERAS), not only for humanitarian reasons but also because poorly relieved surgical pain contributes to surgical stress and impairs recovery. A multimodal analgesic approach is advised in order to provide adequate analgesia, reduce opioid consumption, reduce side effects and facilitate the achievement of ERAS milestones. For open surgery, a thoracic epidural for 48 to 72 hours, with regular acetaminophen and antiinflammatories is probably the treatment of choice. For laparoscopic surgery, intrathecal or local anesthesia in the wound combined with regular acetaminophen and antiinflammatory drugs is effective.

Impact of anaesthetic technique on survival in colon cancer: a review of the literature

An oncological surgical resection is the mainstay of treatment for potentially curable colon cancer. At the time of surgery, a large fraction of patients do harbour—although not visibly—minimal residual disease at the time of surgery. The immunosuppression that accompanies surgery may have an effect on disease recurrence and survival. Regional or neuraxial anaesthetic techniques like epidural anaesthesia may suppress immune function less than opioid analgesia, by reducing stress response and significantly reducing exposure to opioids. Consistent with this hypothesis, regional anaesthetic techniques have been associated with lower recurrence rates in breast cancer and prostate cancer. Results for colon cancer, however, are contradictory. In this review of the literature we describe all studies addressing the association of the use of epidural anaesthesia and survival in colon cancer surgery.

Outpatient colectomy within an enhanced recovery program

INTRODUCTION

The application of a fast-track recovery program after surgery can decrease the physiological impact of surgery and reduce the duration of hospitalisation compared to conventional care. This program has permitted us to consider the performance of colectomy on an outpatient basis.

METHOD

After analyzing the recommendations for fast-track recovery, we developed and validated a specific protocol. Drawing on extensive experience in ambulatory surgery (inguinal hernia, cholecystectomy, adjustable gastric-banding), we formalized a protocol for outpatient colectomy. Patient selection criteria were the absence of serious or decompensated comorbidity, very good general condition, and full patient understanding of the procedure. Discharge was authorized if the patient met the exit criteria according to the Chung score. Postoperative surveillance was provided by regular home visits of a nurse trained in enhanced recovery, every afternoon until day 10.

RESULTS

Five patients underwent this management strategy (4 men and 1 woman, mean age 64 years, range: 59-69), for indications including cancer of the rectosigmoid junction (1 case), sigmoid diverticulitis (3 cases), and volvulus. The postoperative course was simple and uncomplicated except for two patients who had dysuria and an incisional hematoma, respectively.

CONCLUSION

To our knowledge, these are the first cases of colectomy performed strictly on an outpatient basis (i.e., stay<12h). We demonstrated the feasibility of outpatient colectomy when integrated into a protocol of enhanced recovery for selected patients provided that at-home monitoring was available.

Opioids and cancer recurrence

PURPOSE OF REVIEW

With the majority of deaths from cancer because of their metastases, strategies to reduce this from occurring are at the forefront of treatment. It has been hypothesized that morphine may result in an increase in cancer metastases, following many in-vitro and animal studies, but the evidence from human retrospective data is inconclusive. This article will explore the possible mechanisms by which opioids can impact on the natural history of the cancer cell and whether they are likely to be harmful in individuals with cancer.

RECENT FINDINGS

Although there have been trials demonstrating benefits with regional anaesthesia techniques (opioid sparing) in the surgical population, it is not clear whether the source of the benefit arises directly from the avoidance of opioids or an added benefit afforded by regional anaesthesia. Research has shown that in particular cancer cell types, morphine may actually be beneficial and that the μ-opioid receptor (MOR) plays a role in cancer disease. With the crystal structure of the MOR having recently been elucidated, this may offer new opportunities for treatments aimed at reducing cancer metastasis.

SUMMARY

The role opioids play in the development of cancer metastasis and recurrence is far from clear and appears to differ depending on the cancer cell type in question. Prospective randomized controlled trials are currently underway in humans to help clarify the situation further and there results are awaited with anticipation. The negative impact of pain on the immune system is well documented and it appears that appropriate analgesia is paramount in minimizing this. Opioids still constitute a central role in the management of moderate-to-severe cancer pain.

[Interaction of anesthetics and analgesics with tumor cells]

The results of preclinical and clinical studies indicate that the perioperative period is a vulnerable period for cancer progression and metastasis. The risk of cancer cell dissemination is enhanced by the combination of surgical manipulation and perioperative immunosuppression. Whether the oncological outcome of cancer patients can be influenced by the choice of anesthetic techniques is still a matter of debate. This review summarizes the molecular characteristics of cancer and interaction of anesthetic and analgesic drugs with cancer cells.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.

Anaesthetic techniques for risk of malignant tumour recurrence

BACKGROUND

Surgery remains a mainstay of treatment for malignant tumours; however, surgical manipulation leads to a significant systemic release of tumour cells. Whether these cells lead to metastases is largely dependent on the balance between aggressiveness of the tumour cells and resilience of the body. Surgical stress per se, anaesthetic agents and administration of opioid analgesics perioperatively can compromise immune function and might shift the balance towards progression of minimal residual disease. Regional anaesthesia techniques provide perioperative pain relief; they therefore reduce the quantity of systemic opioids and of anaesthetic agents used. Additionally, regional anaesthesia techniques are known to prevent or attenuate the surgical stress response. In recent years, the potential benefit of regional anaesthesia techniques for tumour recurrence has received major attention and has been discussed many times in the literature. In preparing this review, we aimed to summarize the current evidence systematically and comprehensively.

OBJECTIVES

To establish whether anaesthetic technique (general anaesthesia versus regional anaesthesia or a combination of the two techniques) influences the long-term prognosis for individuals with malignant tumours.

SEARCH METHODS

We searched The Cochrane Library (2013, Issue 12), PubMed (1950 to 15 December 2013), EMBASE (1974 to 15 December 2013), BIOSIS (1926 to 15 December 2013) and Web of Science (1965 to 15 December 2013). We handsearched relevant websites and conference proceedings and reference lists of cited articles. We applied no language restrictions.

SELECTION CRITERIA

We included all randomized controlled trials or controlled clinical trials that investigated the effects of general versus regional anaesthesia on the risk of malignant tumour recurrence in patients undergoing resection of primary malignant tumours. Comparisons of interventions consisted of (1) general anaesthesia alone versus general anaesthesia combined with one or more regional anaesthetic techniques; (2) general anaesthesia combined with one or more regional anaesthetic techniques versus one or more regional anaesthetic techniques; and (3) general anaesthesia alone versus one or more regional anaesthetic techniques. Primary outcomes included (1) overall survival, (2) progression-free survival and (3) time to tumour progression.

DATA COLLECTION AND ANALYSIS

Two review authors independently scanned the titles and abstracts of identified reports and extracted study data.All primary outcome variables are time-to-event data. If the individual trial report provided summary statistics with odds ratios, relative risks or Kaplan-Meier curves, extracted data enabled us to calculate the hazard ratio using the hazard ratio calculating spreadsheet. To assess risk of bias, we used the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included four studies with a total of 746 participants. All studies included adult patients undergoing surgery for primary tumour resection. Two studies enrolled male and female participants undergoing major abdominal surgery for cancer. One study enrolled male participants undergoing surgery for prostate cancer, and one study male participants undergoing surgery for colon cancer. Follow-up time ranged from nine to 17 years. All four studies compared general anaesthesia alone versus general anaesthesia combined with epidural anaesthesia and analgesia. All four studies are secondary data analyses of previously conducted prospective randomized controlled trials.Of the four included studies, only three contributed to the outcome of overall survival, and two each to the outcomes of progression-free survival and time to tumour progression. In our meta-analysis, we could not find an advantage for either study group for the outcomes of overall survival (hazard ratio (HR) 1.03, 95% confidence interval (CI) 0.86 to 1.24) and progression-free survival (HR 0.88, 95% CI 0.56 to 1.38). For progression-free survival, the level of inconsistency was high. Pooled data for time to tumour progression showed a slightly favourable outcome for the control group (general anaesthesia alone) compared with the intervention group (epidural and general anaesthesia) (HR 1.50, 95% CI 1.00 to 2.25).Quality of evidence was graded low for overall survival and very low for progression-free survival and time to tumour progression. The outcome of overall survival was downgraded for serious imprecision and serious indirectness. The outcomes of progression-free survival and time to tumour progression were also downgraded for serious inconsistency and serious risk of bias, respectively.Reporting of adverse events was sparse, and data could not be analysed.

AUTHORS' CONCLUSIONS

Currently, evidence for the benefit of regional anaesthesia techniques on tumour recurrence is inadequate. An encouraging number of prospective randomized controlled trials are ongoing, and it is hoped that their results, when reported, will add evidence for this topic in the near future.

Effect of anaesthetic technique on the natural killer cell anti-tumour activity of serum from women undergoing breast cancer surgery: a pilot study

BACKGROUND

Animal models and retrospective clinical data suggest that certain anaesthetic techniques can attenuate immunosuppression and minimize metastasis after cancer surgery. Natural killer (NK) T cells are a critical component of the anti-tumour immune response. We investigated the effect of serum from women undergoing primary breast cancer surgery, randomized to propofol-paravertebral block (PPA) or sevoflurane-opioid (GA) anaesthetic techniques, on healthy human donor NK cell function and cytotoxicity against oestrogen and progesterone receptor-positive breast cancer cells (HCC1500).

METHODS

Ten subjects who donated serum before operation and 24 h after operation in an ongoing randomized prospective trial (NCT 00418457) were randomly selected. Serum from PPA (n=5) and GA (n=5) subjects was co-cultured with HCC1500 and healthy primary NK cells. NK cell activating receptors (NKp30, NKp44, NKp46, 2b4, CD16, NKG2D), cytokine production, NK CD107a expression, and cytotoxicity towards HCC1500 were examined.

RESULTS

Serum from PPA subjects did not alter normal NK marker expression or secretion of cytokines. Serum from GA subjects reduced NK cell activating receptor CD16 [from mean (sem), 82 (2)% to 50 (4)%, P=0.001], IL-10 [from 1700 (80) to 1200 (92) pg ml(-1), P=0.001], and IL-1β [from 68 (12) to 19 (4) pg ml(-1), P=0.01]. An increase in NK cell CD107a [23 (2)% to 37(3)%, P=0.007] and apoptosis of HCC1500 [11 (1)% to 21 (2)%, P=0.0001] was observed with PPA serum, but not GA serum, treated NK cells.

CONCLUSION

Serum from women with breast cancer undergoing surgical excision who were randomized to receive a PPA anaesthetic technique led to greater human donor NK cell cytotoxicity in vitro compared with serum from women who received GA.

CLINICAL TRIAL REGISTRATION

NCT 041857.