Effective integration of pain management into comprehensive cancer care.

Pain management is an integral component of comprehensive cancer care. The combined goals of optimal comfort and optimal function require a working understanding of how pain therapy interacts with cancer and cancer therapy. The two main aspects of cancer which affect pain management are the cancer's treatability and its non-pain pathophysiology. Cancer treatability determines the importance of pain management and the appropriateness of invasive pain-blocking procedures. Cancer non-pain pathophysiology often hinders pain control by preventing oral administration of medications, narrowing a patient's therapeutic window for opioid analgesics, limiting psychological therapies, and interfering with invasive pain relieving procedures. Cancer therapy can impair or enhance pain therapy and vice versa. Cancer therapy can impair pain therapy by its production of adverse effects or by its direct causation of pain. Cancer therapy can enhance pain therapy by reducing the amount of cancer, by including drugs which act as coanalgesics, and by providing intravenous access devices for parenteral opioid administration. Pain therapy can impair cancer therapy by augmenting or complicating cancer therapy's adverse effects. Pain therapy can enhance cancer therapy by improving organ function and patient performance status permitting previously limited or contraindicated cancer therapies to be given. Five case studies are presented to illustrate how effective integration of pain management into comprehensive cancer care is mandatory for optimal care of cancer patients and their families.