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.

Background The deep serratus anterior plane block (SAPB) is a promising novel regional anaesthesia technique for blockade of the anterolateral chest wall. Evidence for the efficacy of SAPB versus other analgesic techniques in thoracic surgery remains inadequate. Aims This study compared ultrasound‐guided continuous SAPB with a surgically placed continuous thoracic paravertebral block (SPVB) technique in patients undergoing videoscopic‐assisted thoracic surgery (VATS). Methods In a single‐centre, double‐blinded, randomized, non‐inferiority study, we allocated 40 patients undergoing VATS to either SAPB or SPVB, with both groups receiving otherwise standardized treatment, including multimodal analgesia. The primary outcome was 48‐hr opioid consumption. Secondary outcomes included numerical rating scale (NRS) for postoperative pain, patient‐reported worst pain score (WPS) as well as functional measures (including mobilization distance and cough strength). Results A 48‐hr opioid consumption for the SAPB group was non‐inferior compared with SPVB. SAPB was associated with improved NRS pain scores at rest, with cough and with movement at 24 hr postoperatively (p = .007, p = .001 and p = .012, respectively). SAPB was also associated with a lower WPS (p = .008). Day 1 walking distance was improved in the SAPB group (p = .012), whereas the difference in cough strength did not reach statistical significance (p = .071). There was no difference in haemodynamics, opioid side effects, length of hospital stay or patient satisfaction between the two groups. Conclusions The SAPB, as part of a multimodal analgesia regimen, is non‐inferior in terms of 48‐hr opioid consumption compared to SPVB and is associated with improved functional measures in thoracic surgical patients. ClinicalTrials.gov Identifier: NCT03768193. Significance The SAPB interfascial plane block is an efficacious alternative method of opioid‐sparing analgesia in high‐risk thoracic surgical patients as part of an enhanced recovery programme.

Background Some experimental and retrospective clinical studies signal an association between certain anaesthetic techniques and tumour metastasis following breast cancer surgery. Neutrophil Extracellular Trapping (NETosis) is an immunological process, whereby neutrophils engulf tumour antigen then degranulate, leaving a serologic marker. NETosis expression among breast cancer patients is associated with an increased risk of metastasis. We investigated the effect of two distinct anaesthetic techniques on the expression of NETosis in women who underwent potentially curative breast cancer surgery. Methods In a parallel‐group, randomised controlled trial, a subset of women (n = 40) undergoing breast cancer resection surgery, who were partaking in a larger trial (NCT00418457), were randomly assigned to receive volatile general anaesthesia (GA) or propofol GA combined with paravertebral regional anaesthesia (PPA) for their surgery. Serum was taken and stored before and 24 hours post‐operatively. NETosis was measured by ELISA using Neutrophil Myeloperoxidase (MPO) and citrullinated histone H3 (H3Cit) biomarkers, which were the co‐primary end points. Results Patient and breast cancer characteristics did not differ significantly between groups. Recurrence occurred in 7.5% patients. GA patients received more opioids and reported higher post‐operative pain than PPA. There was no difference in post‐operative MPO in GA vs PPA (10.5 ± 6.6 vs 11.5 ± 4.7 ng mL−1, P = .60). Regarding CitH3, there was no difference post‐operatively in GA vs PPA (3.6 ± 2.3 vs 4.0 ± 5.9, P = .80). NET expression did not differ before or after anaesthesia and surgery in either group, for either biomarker. Conclusion Anaesthetic technique did not affect NETosis expression in breast cancer patients, indicating that it is not a viable marker of the effect of anaesthetic technique on breast cancer recurrence.