Perioperative events influence cancer recurrence risk after surgery. Nat Rev Clin Oncol. 2018;15:205-218. [PMID: 29283170 DOI: 10.1038/nrclinonc.2017.194]

Inhalational versus Propofol-Based Total Intravenous Anaesthesia: Practice Patterns and Perspectives among Australasian Anaesthetists

Increasing evidence suggests that total intravenous anaesthesia (TIVA) may be the preferred anaesthetic for cancer resection surgery. To assist the preparation of a randomised controlled trial (RCT) examining Volatile (versus TIVA) Anaesthesia and Perioperative Outcomes Related to Cancer (VAPOR-C) we developed an 18-question electronic survey to investigate practice patterns and perspectives (emphasising indications, barriers, and impact on cancer outcomes) of TIVA versus inhalational general anaesthesia in Australasia. The survey was emailed to 1,000 (of 5,300 active Fellows) randomly selected Australian and New Zealand College of Anaesthetists (ANZCA) Fellows. The response rate was 27.5% (n=275). Of the respondents, 18% use TIVA for the majority of cases. In contrast, 46% use TIVA 20% of the time or less. Respondents described indications for TIVA as high risk of nausea, neurosurgery, and susceptibility to malignant hyperthermia. Lack of equipment, lack of education and cost were not considered barriers to TIVA use, and a significant proportion (41%) of respondents would use TIVA more often if setup were easier. Of the respondents, 43% thought that TIVA was associated with less cancer recurrence than inhalational anaesthesia, while 46% thought that there was no difference. Yet, only 29% of respondents reported that they use TIVA often or very often for cancer surgery. In Australasia, there is generally a low frequency of TIVA use despite a perception of benefit when compared with inhalational anaesthesia. Anaesthetists are willing to use TIVA for indications where sufficient evidence supports a meaningful level of improvement in clinical outcome. The survey explores attitudes towards use of TIVA for cancer surgery and demonstrates equipoise in anaesthetists’ opinions regarding this indication. The inconsistent use of TIVA in Australasia, minimal barriers to its use, and the equipoise in anaesthetists’ opinions regarding the effect of TIVA versus inhalational anaesthesia on cancer outcomes support the need for a large prospective RCT.

The effect of epidural analgesia on cancer progression in patients with stage IV colorectal cancer after primary tumor resection: A retrospective cohort study

Retrospective clinical studies showed perioperative epidural analgesia (EA) was associated with better postoperative oncologic outcomes in patients with specific types of non-metastatic cancers. This study aimed to investigate the effects of EA on cancer prognosis after surgical intervention for stage IV colorectal cancer. In this retrospective study, patients with stage IV colorectal cancer undergoing primary tumor resection and metastasectomy between January 2005 and December 2014 were classified into two groups based on their use of perioperative EA or not and evaluated through August 2016. Primary and secondary endpoints were postoperative progression-free survival (PFS) and overall survival (OS), respectively. A total of 999 patients were included and 165 (16.5%) of them received EA. The median follow-up interval was 17.5 months and no significant difference in PFS or OS was noted between the EA and non-EA groups in the univariate analysis. Multivariable Cox proportional hazards model identified four independent risk factors both for disease progression and mortality, including American Society of Anesthesiologists (ASA) physical status ≥ 3, higher pretreatment carcinoembryonic antigen (CEA), multiple distant metastases, and pathologic lymphovascular invasion. After adjustment for the selected risk factors, the effects of EA on PFS and OS remained non-significant (hazard ratio: 1.06, 95% CI: 0.87 to 1.29, for PFS and 0.90, 95% CI: 0.68 to 1.20 for OS). Similar findings were demonstrated by propensity score analysis. Our results did not support the association between perioperative epidural analgesia and better progression-free or overall survival in patients following stage IV colorectal cancer surgery.

Effect of beta-blockers on cancer recurrence and survival: a meta-analysis of epidemiological and perioperative studies

BACKGROUND

The biological perturbation associated with psychological and surgical stress is implicated in cancer recurrence. Preclinical evidence suggests that beta-blockers can be protective against cancer progression. We undertook a meta-analysis of epidemiological and perioperative clinical studies to investigate the association between beta-blocker use and cancer recurrence (CR), disease-free survival (DFS), and overall survival (OS).

METHODS

Databases were searched until September 2017, reported hazard ratios (HRs) pooled, and 95% confidence intervals (CIs) calculated. Comparative studies examining the effect of beta-blockers (selective and non-selective) on cancer outcomes were included. The Newcastle Ottawa Scale was used to assess methodological quality and bias.

RESULTS

Of the 27 included studies, nine evaluated the incidental use of non-selective beta-blockers, and ten were perioperative studies. Beta-blocker use had no effect on CR. Within subgroups of cancer, melanoma was associated with improved DFS (HR 0.03, 95% CI 0.01-0.17) and OS (HR 0.04, 95% CI 0.00-0.38), while endometrial cancer had an associated reduction in DFS (HR 1.40, 95% CI 1.10-1.80) and OS (HR 1.50, 95% CI 1.12-2.00). There was also reduced OS seen with head and neck and prostate cancer. Non-selective beta-blocker use was associated with improved DFS and OS in ovarian cancer, improved DFS in melanoma, but reduced OS in lung cancer. Perioperative studies showed similar variable effects across cancer types, albeit from a limited data pool.

CONCLUSION

Beta-blocker use had no evident effect on CR. The beneficial effect of beta-blockers on DFS and OS in the epidemiological or perioperative setting remains variable, tumour-specific, and of low-level evidence at present.

Systematic review and consensus definitions for standardised endpoints in perioperative medicine: postoperative cancer outcomes

BACKGROUND

The Standardising Endpoints for Perioperative Medicine group was established to derive an appropriate set of endpoints for use in clinical trials related to anaesthesia and perioperative medicine. Anaesthetic or analgesic technique during cancer surgery with curative intent may influence the risk of recurrence or metastasis. However, given the current equipoise in the existing literature, prospective, randomised, controlled trials are necessary to test this hypothesis. As such, a cancer subgroup was formed to derive endpoints related to research in onco-anaesthesia based on a current evidence base, international consensus and expert guidance.

METHODS

We undertook a systematic review to identify measures of oncological outcome used in the oncological, surgical, and wider literature. A multiround Delphi consensus process that included up to 89 clinician-researchers was then used to refine a recommended list of endpoints.

RESULTS

We identified 90 studies in a literature search, which were the basis for a preliminary list of nine outcome measures and their definitions. A further two were added during the Delphi process. Response rates for Delphi rounds one, two, and three were 88% (n=9), 82% (n=73), and 100% (n=10), respectively. A final list of 10 defined endpoints was refined and developed, of which six secured approval by ≥70% of the group: cancer health related quality of life, days alive and out of hospital at 90 days, time to tumour progression, disease-free survival, cancer-specific survival, and overall survival (and 5-yr overall survival).

CONCLUSION

Standardised endpoints in clinical outcomes studies will support benchmarking and pooling (meta-analysis) of trials. It is therefore recommended that one or more of these consensus-derived endpoints should be considered for inclusion in clinical trials evaluating a causal effect of anaesthesia-analgesia technique on oncological outcomes.