The International Association for the Study of Pain defines pain as an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. Cancer pain can be managed effectively through relatively simple means in up to 90% of the eight million Americans who have cancer or a history of cancer. Unfortunately, pain associated with cancer is frequently undertreated.
The highest prevalence of severe pain occurs in adult patients with advanced cancer. Chronic pain is an issue in cancer patients, with up to 33% continuing to have pain after curative therapy. During active cancer treatment and in advanced disease states, tumors cause most pain. However, survivors are affected more by pain related to modalities such as surgery, chemotherapy, or radiation therapy than by cancer-related pain. One summary provides an excellent review of troublesome symptoms in cancer survivors, including pain.[Level of evidence: IV]
Check NCI's list of cancer clinical trials for cancer CAM clinical trials on marijuana, nabilone, dronabinol and nabiximols that are actively enrolling patients.
General information about clinical trials is available from the NCI Web site.
Although cancer pain or associated symptoms often cannot be entirely eliminated, appropriate use of available therapies can effectively relieve pain in most patients. Pain management improves the patient's quality of life throughout all stages of the disease. Patients with advanced cancer experience multiple concurrent symptoms with pain; therefore, optimal pain management necessitates a systematic symptom assessment and appropriate management for optimal quality of life. Despite the wide range of available pain management therapies, data are insufficient to guide their use in children, adolescents, older adults, and special populations.
State and local laws often restrict the medical use of opioids to relieve cancer pain, and third-party payers may not reimburse for noninvasive pain-control treatments. Thus, clinicians should work with regulators, state cancer pain initiatives, or other groups to eliminate these health care system barriers to effective pain management. (These and other barriers to effective pain management are listed below.) Changes in health care delivery may create additional disincentives for clinicians to practice effective pain management.
The U.S. Food and Drug Administration Amendments Act of 2007 requires manufacturers to provide risk evaluation and mitigation strategies (REMS) for selected drugs to ensure that benefits outweigh risks. A major component of REMS requires prescribers to obtain training so that these drugs can be safely used.