57 The role of anaesthetic techniques in influencing long-term cancer outcomes has been a subject of increasing interest among researchers. A recent narrative review delved into this issue, examining evidence from clinical and experimental studies to determine if specific types of anaesthesia can affect cancer recurrence and metastasis. The findings were published in the journal Anaesthesia. Surgical removal of tumours remains a primary curative option for many cancers. However, the perioperative period is a critical time when microscopic residual tumour cells may proliferate due to immune suppression and inflammatory responses triggered by surgery. Researchers have explored whether the choice of anaesthesia might exacerbate or mitigate these risks, focusing on commonly used techniques such as volatile anaesthetic agents, total intravenous anaesthesia (TIVA), local anaesthetics, and regional anaesthesia. Volatile anaesthetic agents, including isoflurane and sevoflurane, have been shown in laboratory settings to potentially promote tumour growth by activating cellular pathways linked to proliferation. However, clinical studies have found mixed results, with large registry analyses failing to demonstrate a significant impact on overall survival or cancer recurrence. In contrast, propofol, used in TIVA, has shown anti-tumour properties in preclinical studies by inducing cancer cell death and reducing metastatic potential. Despite these promising findings, randomised controlled trials have not confirmed any survival advantage for patients receiving propofol-based anaesthesia compared to volatile agents. Local anaesthetics have emerged as a particularly intriguing option. Evidence suggests that they can directly kill cancer cells and modulate the immune system to enhance anti-tumour responses. A landmark trial involving women undergoing breast cancer surgery found that peritumoural lidocaine infiltration significantly improved disease-free and overall survival rates. These findings highlight a potential area for further research and clinical application. The potential benefits of regional anaesthesia, such as epidurals, have also been investigated. Although early observational studies suggested a possible reduction in recurrence rates, subsequent randomised trials have shown no significant difference in outcomes compared to general anaesthesia. Opioids, often used for pain management during and after surgery, have a dual reputation. While some studies suggest that opioids may promote tumour progression by impairing immune responses, others indicate they might offer protective benefits by effectively managing surgical stress and pain. The exact role of opioids in cancer outcomes likely depends on factors such as tumour type and individual genetic profiles. Overall, the review underscores the complexity of interactions between anaesthetic techniques and cancer biology. While laboratory data suggest that certain agents may influence cancer progression, clinical evidence remains inconclusive. Further high-quality randomised trials are needed to clarify these effects and guide anaesthetic practices for cancer surgery.