Special issue on anaesthesia and cancer.

The hypothesis that anaesthetic and analgesic technique during cancer surgery affects recurrence or metastasis was first proposed in 2006 and has since become one of the most important research questions in the speciality, as confirmed in a recent research priority setting exercise. Building on the success of the inaugural BJA Workshop on Anaesthetic Neurotoxicity and Neuroplasticity held in Salzburg in 2012, which lead to a Special Online Issue of BJA, a group of researchers with a proven publication track record in the field of anaesthesia and cancer recurrence and metastasis convened in the College of Anaesthetists of Ireland in Dublin (see cover image) on May 29–30, 2013, for the BJA Dublin Research Workshop on Anaesthesia and Analgesia in Cancer. This 2 day meeting, sponsored by BJA, was organized to reviewand critically assess currently available evidence from experimental cell culture models and live animal models, together with translational and clinical studies, and to identify priorities for future research directions. Organized by D.J.B. (Dublin), it convened more than 20 clinician investigators in anaesthesia, oncology, immunology, and opioid pharmacologists from around the world for an intensive series of lectures and discussions. The result is this BJA Special Issue on Anaesthesia and Cancer, a collection of cutting-edge original investigations from the delegates and other investigators who submitted papers following a call for manuscripts from BJA. Like the inaugural Special Issue on Neurotoxicity, this themed issue is again presented in open access format via the BJA website (http://bja.oxfordjournals.org), which confirms the journal’s commitment to supporting topical research and facilitating its free rapid dissemination online. It consists of 13 original investigations and a short overview encompassing a consensus statement. A systematic review of this subject was published recently. The original manuscripts may be classified as investigations of direct effects of anaesthetic and analgesic drugs on cancer cell biology (5), translational studies on the effect of anaesthetic technique in randomized cancer surgery patients on perioperative host immunity and cancer metastatic function (3), and new retrospective clinical data on perioperative factors associated with subsequent recurrence or metastasis (6). The section on direct effects of anaesthetic–analgesic drugs on cancer biology is ignited by J. Nguyen, K. Luk, and colleagues, with an elegant series of live animal experiments using a transgenic mouse model of breast cancer. These mice, programmed to develop breast tumours, were treated at different ages with clinically relevant doses of morphine to determine the effect on tumour development and animal survival. While morphine was absolved of instigating tumour development, it clearly enhanced progression of established tumours, mediated by tumourexpression ofm-opioid receptors (MOR). Ash and colleagues undertook novel work on the anaesthetic gas xenon in breast cancer cells and found that in contrast to sevoflurane, it inhibits breast cancercell migration byan N-methyl-D-aspartate receptor-mediated mechanism, and decreased release of the angiogenesis factor RANTES in oestrogen receptor-negative breast cancer cells. Afsharimani and colleagues co-cultured breast cancer cells with macrophages or endothelial cells to study the effect of non-steroidal anti-inflammatory drugs (NSAIDs) and antifibrinolytic agents on extracellular membrane proteases which regulate the tumour microenvironment, and found mixed results, which warrant further investigation in animal and clinical studies. There has been great interest in recent cell culture data suggesting inhibitoryeffects of amide local anaesthetics on cancer cell function, which is progressed here by Lirk and colleagues,