Effect of regional anaesthesia only versus general anaesthesia on cancer recurrence rate: A systematic review and meta-analysis with trial sequential analysis
Creators: name: Ang, Eshen
name: Ng, Ka Ting
name: Lee, Zong Xuan
name: Ti, Lian Kah
name: Chaw, Sook Hui
name: Chew Yin Wang
Publisher: name: Zenodo
Year: 2020
Subjects: Regional Anaesthesia
General Anaesthesia
Cancer
Recurrence
Rates
Trial sequential analysis
Systematic review
Meta analysis

description: <strong>Introduction </strong>There is growing evidence on the influence of general anaesthesia (GA) in promoting the proliferation of cancer cells. RA comprised of epidural, spinal and nerve block, which can attenuate surgical stress response by reducing catecholamine levels and minimizing immunosuppression. The benefits of regional anaesthesia (RA) on cancer recurrence rate in cancer surgery remains unclear in the literature. <strong>Objectives </strong>To examine the effect of RA-only on the incidence of post-operative cancer recurrence rate in cancer resection surgery. <strong>Methods</strong> This review was conducted and reported in adherence to the Cochrane Handbook and PRISMA statement 2015. The protocol was registered and published on a public database, PROSPERO (CRD42020163780). Databases: MEDLINE, EMBASE and CENTRAL (its inception until April 2020) Inclusion criteria: Randomized clinical trials, observational studies (cohort or case-control) Exclusion criteria: Case reports, case series and editorials Primary outcome: Incidence of cancer recurrence rate Secondary outcomes: Overall survival rate, time to cancer recurrence and cancer-related mortality All the included observational studies were assessed for risk of bias using the Newcastle-Ottawa Scale. <strong>Results </strong>The titles and abstracts of 4477 non-duplicate articles were screened, of which 44 articles were retrieved. After applying inclusion and exclusion criteria, 10 observational studies with a total of 9708 patients (4567 GA vs 5141 RA-only) were included for qualitative and quantitative meta-analysis. In comparison to GA, RA-only was not significantly associated with a lower cancer recurrence rate in cancer resection surgery (p=0.95, certainty of evidence=very low, Fig 1). However, the trial sequential analysis for cancer recurrence rate was inconclusive (Fig 2). Our analysis demonstrated no significant difference between the RA-only and GA groups in the overall survival rate (odds ratio 1.51, 95% CI 0.65 to 3.51, p=0.34, certainty of evidence=very low), time to cancer recurrence (mean difference 1.45 months, 95% CI -8.69 to 11.59, p=0.78, certainty of evidence=very low) and cancer-related mortality (odds ratio 1.79, 95% CI 0.57 to 5.62, p=0.32, certainty of evidence=very low). <strong>Discussion </strong>First meta-analysis of the effect of RA-only versus routine care GA in cancer resection surgery. At present, only 22.2% of required information size (16031 patients) available to detect significance difference of 20% reduction in incidence of cancer recurrence. Substantial heterogeneity non-RCT, inadequate sample size True effect of GA-only may be skewed by many small sample size observational studies with conflicting results and substantial heterogeneity. Confounding factors: types of GA (TIVA/ volatile), amount of opioids use, types of cancer surgery. <strong>Conclusions </strong>Given the low level of evidence and underpowered trial sequential analysis, our review neither support nor oppose that the use of RA-only was associated with lower incidence of cancer recurrence rate than GA in cancer resection surgery.