•Metastatic disease is the most important cause of cancer-related death in patients after cancer surgery.
•Drugs and techniques used perioperatively may influence outcome.
•In vitro and animal study evidence suggests potential mechanisms altered by anaesthetic drugs.
•Human studies are limited but regional anaesthesia may be beneficial.
•There is a need for large-scale prospective studies.
Four potential mechanisms that may promote metastasis after surgery have been proposed (Table 1).
i.Handling and disrupting the tumour during surgery releases tumour cells into the circulation. Polymerase chain reaction can detect tumour cells in patient blood, and their number has been shown to increase after surgery.18
ii.The presence of the primary tumour may itself inhibit angiogenesis, and therefore, tumour removal may eliminate a safeguard against angiogenesis. This may promote survival and growth of minimal residual disease.
iii.Local and systemic release of growth factors during surgery may promote tumour recurrence both locally and at distant sites. EGF and transforming growth factor-β levels are increased, as is VEGF. In addition, anti-angiogenic factors, such as angiostatin and endostatin, may be reduced by surgery.9
iv.There is perioperative immunosuppression, including the cellular immune system. This is a result of both the neuroendocrine and cytokine stress response to surgery,19 and the effect of anaesthetic technique and other perioperative factors.