Authors' objectives:

Pain associated with cancer is an important problem for large numbers of patients and their families. This report summarizes published evidence on the prevalence of cancer-related pain and the efficacy of drug and nondrug therapies for its treatment.

Authors' results and conclusions: The median number of patients enrolled in randomized trials of primary analgesics (NSAIDs, opioids, and adjuvants) was 70 or fewer. Information about the location, nature, and mechanism of pain before and after treatment was minimal for all interventions examined. Heterogeneous reporting of outcomes, nonuniformity of pain measurements, and incomplete reporting of relevant data precluded all but three meta-analyses. Nonsteroidal anti-inflammatory drugs (NSAIDs) or opioids independently reduce cancer-related pain, as do adjuvants such as antidepressants or anticonvulsants. Few studies evaluate the safety and efficacy of NSAIDs for cancer pain beyond a few days; many are single-dose studies. The studies we examined neither separated the analgesic efficacy of NSAIDs and opioids nor indicated that NSAIDs are specifically effective for bone pain nor disclosed incremental efficacy of adding a "weak" opioid to an NSAID. Comparisons between dosages and delivery forms of systemically administered opioids are limited. Radionuclides and biphosphonates reduce pain from bone involvement by tumor, as does external beam radiation, although studies of the latter lack no-radiation controls. Neurolytic celiac block is effective. The analgesic efficacy of palliative chemotherapy and hormonal interventions is difficult to estimate because of inadequate data. Physical or psychological treatments appear efficacious, but the number of relevant studies is small. Multidrug (or drug plus nondrug) therapy, spinal drug infusion, and ablative neurosurgery require better-quality evidence.

Authors' recommendations: Randomized controlled trials establish that many current treatment modalities can individually reduce cancer pain. These trials constitute about 1 percent of the published literature on cancer pain, enroll 1 in 10,000 patients at risk for cancer pain in developed countries, are often heterogeneous, and are often of poor methodologic quality. Many clinical questions remain unanswered and preclinical insights untranslated because of a lack of high-quality evidence. Age, gender, genetics, psychosocial context, and culture affect pain and analgesic efficacy. Multiple mechanisms of cancer pain exist. Despite the importance of pediatric cancer pain control, very few studies focus on children. High-quality trials are needed to advance progress in cancer pain relief.

Authors' methods: Systematic review

Project Status: Completed

URL for project: http://www.ahrq.gov/clinic/epcsums/canpainsum.htm

Year Published: 2001

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Agency for Healthcare Research and Quality

Contact Address: Center for Outcomes and Evidence Technology Assessment Program, 540 Gaither Road, Rockville, MD 20850, USA. Tel: +1 301 427 1610; Fax: +1 301 427 1639;

Contact Name: martin.erlichman@ahrq.hhs.gov

Contact Email: martin.erlichman@ahrq.hhs.gov

Copyright: Agency for Healthcare Research and Quality (AHRQ)