A systematic review of randomized trials on the effectiveness of opioids for cancer pain.

BACKGROUND: In all recommended guidelines put forth for the treatment of cancer pain, opioids continue to be an important part of a physician's armamentarium. Though opioids are used regularly for cancer pain, there is a paucity of literature proving efficacy for long-term use. Cancer is no longer considered a "terminal disease"; 50% to 65% of patients survive for at least 2 years, and there are about 12 million cancer survivors in the United States. There is a concern about side effects, tolerance, abuse and addiction with long-term opioid use and a need to evaluate the effectiveness of opioids for cancer pain. OBJECTIVE: The objective of this systematic review was to look at the effectiveness of opioids for cancer pain. STUDY DESIGN: A systematic review of randomized trials of opioids for cancer pain. METHODS: A comprehensive review of the current literature for randomized controlled trials (RCTs) of opioids for cancer pain was done. The literature search was done using PubMed, EMBASE, Cochrane library, clinical trials, national clearing house, Web of Science, previous narrative systematic reviews, and cross references. The studies were assessed using the modified Cochrane and Jadad criteria. Analysis of evidence was done utilizing the modified quality of evidence developed by United States Preventive Services Task Force (USPSTF). OUTCOME MEASURES: Pain relief was the primary outcome measure. Secondary outcome measures are quality of life (QoL) and side effects including tolerance and addiction. RESULTS: The level of evidence for pain relief based on the USPSTF criteria was fair for transdermal fentanyl and poor for morphine, tramadol, oxycodone, methadone, and codeine. LIMITATIONS: Randomized trials in a cancer setting are difficult to perform and justify. There is a paucity of long-term trials and this review included a follow-up period of only 4 weeks. CONCLUSION: This systematic review of RCTs of opioids for cancer pain showed fair evidence for the efficacy of transdermal fentanyl and poor evidence for morphine, tramadol, oxycodone, methadone, and codeine.

Opioid abuse in cancer pain: report of two cases and presentation of an algorithm of multidisciplinary care.

BACKGROUND: The growing awareness of opioid abuse and addiction in the chronic pain population, along with increasing cancer survivorship, has heightened our awareness of this potential problem in the cancer patient. An increasing number of patients who abuse opioids have been identified in our clinical setting. OBJECTIVE: We present an algorithm of multidisciplinary care for the treatment of cancer patients at risk for abusing opioids. SETTING: Two illustrative patient examples were identified recently from our clinic. RESULTS: These 2 patient examples demonstrate our multidisciplinary approach to treatment. A discussion of safe prescribing principles adapted from the literature is presented. Also, a brief point of added complexity is introduced; specifically, ethical considerations due to the unique nature of cancer pain. LIMITATIONS: Although validation studies exist for the use of screening tools in patients with chronic noncancer pain, there have been no instrument validation studies on patients with cancer pain. The educational treatment model that we refer to regarding facilitating safe use of opioids also has not been studied on patients with cancer pain. Lastly, we express caution in generalizing our guidelines to patients with noncancer pain. Our patient population differs in the multiple co-existing stressors and symptom burden associated with cancer. CONCLUSIONS: We have become increasingly aware of the problem of opioid abuse in the cancer pain population. With an approach to using safe prescribing principles adapted from chronic pain literature, and an ethically based multidisciplinary approach, clinicians can continue to treat pain successfully in the opioid-misusing cancer patient. We outline our approach in this article.