Drugs, Fluids and Cancer

A greater understanding of the pathophysiology and pharmacology related to cancer has led to research into the possible role of the anesthesia drugs and techniques on cancer cell growth, host immunity, metastasis, and recurrence. The anesthetics may also exert a direct (non-immune) effect on the cellular biology of cancer cells by their interaction with specific cell signaling especially the hypoxic inducible factors. Surgery associated neuroendocrine, inflammatory, immune, and metabolic effects are amplified in cancer patients. Opioid remains an acceptable analgesic agent but has been reported to have some role in tumor recurrence. Propofol inhibits Matrix Metalloproteinases (MMP) and prevents tumor spread but has been shown to reduce Natural Killer (NK) cells whereas thiopentone might promote metastasis. Ketamine is associated with the reduction of both NK cell activity and its number. However, many of these reports are from animal models. Volatile agents appear to have negative effects concerning host immunity and tumor metastasis. Non-steroidal anti-inflammatory drugs (NSAIDs) and COX-2 inhibitors may have benefits related to antiangiogenesis and tumor inhibition. Regional anesthesia has been studied with conflicting outcomes but benefits have been attributed to local anesthetic agents. Hypothermia influences function at the cellular level and negatively impacts adaptive immunity. Blood transfusion has an immunomodulatory effect and has an increased risk of cancer recurrence, and perioperative infections. The type and quantity of fluid based on an identified endpoint is also required for an optimal outcome.