Anesthesia and Cancer, Friend or Foe? A Narrative Review

Abstract

Cancer remains the leading cause of death worldwide with close to 10 million deaths reported annually. Due to growth of the advanced age cohort in our population, it is predicted that the number of new cancer cases diagnosed between now until 2035 is to reach potentially 24 million individuals, a staggering increase in a relatively short time period. For many solid tumors, surgical resection along with chemotherapy is the best available approach to a potential cure which leads to almost 80% of cancer patients undergoing at least one surgical procedure during the course of their disease. During surgical intervention, the exposure to general anesthesia can be lengthy, complex and often involves various modalities resulting in an important question as to the role, if any, anesthesia may play in primary recurrence or metastatic conversion. Many components of the stress and inflammatory responses exhibited in the perioperative period can contribute to cancer growth and invasion. The agents used to induce and maintain general anesthesia have variable interactions with the immune and neuroendocrine systems and can influence the stress response during surgery. Thus, debating the best type of anesthesia that would help to attenuate sympathetic and/or pro-inflammatory responses while modulating cytokine release and transcription factors/oncogenes remains at the forefront. This may affect inducible cancer cell survival and migratory abilities not only intra-operatively, but also during the immediate post-operative phase of recovery. The ultimate question becomes how and whether the choice of anesthesia may influence the outcomes of cancer surgery with two major approaches being considered, i.e., regional and general anesthesia as well as the various hypnotics, analgesics and sympatholytics commonly used. In this review, we will address the latest information as to the role that anesthesia may play during cancer surgery with specific focus on primary recurrence and metastasis.

The Impact of Perioperative Events on Cancer Recurrence and Metastasis in Patients after Radical Gastrectomy: A Review

“…Given that the majority of patients with GC will experience at least one anesthesia, the effects of different anesthetic approaches and drugs on the cancer outcomes of GC patients have been increasingly regarded as a research priority. The choices of anesthetic approach (general vs. neuraxial anesthesia), anesthetic agent (inhalational vs. intravenous), and accompanying prescribed analgesic drugs have long been assumed to influence the risk of cancer recurrence [ 24 ]. However, the available limited evidence regarding the effects of these techniques and drugs on cancer recurrence in GC has been inconclusive ( Supplementary Table S2 ).…”

“…However, the available limited evidence regarding the effects of these techniques and drugs on cancer recurrence in GC has been inconclusive ( Supplementary Table S2 ). Regarding anesthetic techniques, epidural anesthesia has populated in recent years in oncological surgery [ 24 ]. A small number of retrospective studies have reported the relationships between epidural anesthesia and GC patient outcomes with conflicting results.…”

Influence of Perioperative Anesthesia on Cancer Recurrence: from Basic Science to Clinical Practice

“…DEX is a highly selective α2 adrenoreceptor agonist and has multiple pharmacologic effects, including hypnosis, analgesia, sedation, and anxiolysis. α2 adrenergic receptors are expressed on both immune cells and tumors, which indicates that DEX may affect the balance of the immune system and tumorigenesis [ 176 , 177 ]. According to a meta-analysis of patient studies by Wang et al, the intraoperative use of DEX infusion increases the numbers of NK cells, B cells, and CD4 + T cells and the ratios of CD4 + /CD8 + and Th1/Th2 cells, while the number of CD8 + T cells is significantly decreased [ 178 ].…”

Regional anesthesia did not improve postoperative long-term survival of tumor patients: a systematic review and meta-analysis of randomized controlled trials

“…Firstly, local anesthetic was involved in mediating tumor growth and metastasis via influencing the biological behavior of tumor cells. Local anesthetics inhibit cell proliferation by inhibiting catecholamines release [ 10 , 11 ]. RA also reduces the excitability of cancer cells by blocking voltage-gated sodium channels, thereby reducing the metastatic potential [ 12 ].…”