Surgical stress response and cancer outcomes: a narrative review

Cancer is a leading cause of worldwide mortality and a major part of surgical workload, with many primary cancer treatments requiring surgical removal as a first line management. Surgery itself is an inherent cause of stress and trauma which generates significant hormonal and metabolic changes within the body. These changes have reaching immunomodulatory effects, which can contribute to development of cancer metastases. Metastasis is the multistage process by which cancer spreads and proliferates within the body and is the leading cause of cancer mortality. In order to spread within the body, cancer cells require vascular networks, evasion of the host’s immune response and invasion at a distant site. In this review article, we discuss mechanisms by which surgery and the resulting stress response can affect the likelihood of metastasis in these ways, both in general and for specific cancer subtypes. We summarise ways in which healthcare providers can minimise these risks in the perioperative period, taking into account the most recent literature and research updates. Currently, most in vivo evidence available is found by looking at retrospective data and we await the outcomes of several large randomised control trials. Patients should be cared for on an individual basis, taking into account the data presented here.