Pain is a common side effect of cancer that can be caused by the disease itself, treatment, and other factors. Greater awareness of the causes and types of cancer pain, knowledge of available treatments, and willingness to consult pain specialists are the keys to providing effective cancer pain management.
Pain is a common complication associated with all types of cancer. However, management of cancer pain varies from physician to physician and patient to patient, as pain can be attributed to a number of factors, including disease process, treatment, and presence of other comorbid conditions. Effectively managing pain associated with cancer can improve outcomes as well as survival.
During a morning session on the final day of the 2013 American Academy of Pain Medicine annual meeting, held April 12-14 in Fort Lauderdale, Florida, Vitaly Gordin, MD, of Penn State Hershey Medical Center in Pennsylvania, moderated a session focusing on improvements in the management and diagnosis of pain associated with cancer.
During the session, Gordin discussed the incidence of cancer pain, noting that approximately 10% of cancer patients with pain fail to achieve adequate pain control according to the WHO guidelines. In addition, approximately 30% have poor pain control. Addressing pain is becoming a more important part of treatment, as more patients are surviving for longer and cancer is becoming more of a chronic condition.
Gordin also discussed the types of cancer pain syndromes, including those caused by the disease process, psychological factors, and drug therapy. He said there are two types of pain syndromes — somatic and neuropathic pain syndrome. Neuropathic pain syndromes include chemotherapy-induced neuropathic pain (CINP), radiation-induced pain, and tumor-induced pain. Although severe pain associated with the disease and/or treatment can hinder cancer treatment, which can decrease survival, Gordin said that unfortunately the trend has been to exclude pain specialists from cancer pain management. Greater involvement of pain specialists in the cancer team and more focus on cancer pain management is essential for improvement of quality of life and survival.
Allen W. Burton, MD, of Houston Pain Associates in Texas, further expanded upon the unmet need in the management of cancer pain. He said studies have shown that approximately 20-30% of cancer is poorly controlled, and some physicians are not aware of the effectiveness of interventional pain approaches. Interventional approaches may be an option in patients with pain that is refractory to medical management or in patients who are unable to tolerate the side effects of drug therapy. It may also be an option for patients with focal pain or who are contraindicated for standard medical management.
There are a variety of options including neuraxial therapy, vertebral augmentation, celiac plexus block, nerve block, radiofrequency, and simple injections. Burton said that cancer pain management is becoming much more like chronic pain management and it should be understood that physicians do not have to follow a traditional pain treatment protocol, as they should design a pain management approach that fits with the patient’s individual needs.
In the last presentation of the session, Larry Driver, MD, of MD Anderson Cancer Center, University of Texas in Houston, discussed some of the difficulties confronting clinicians who try to provide effective cancer pain management, noting that one of the biggest challenges is the sheer number of types and causes of cancer pain, including acute pain, chronic pain, persistent pain, episodic pain, basal pain, breakthrough pain, pain related to disease or treatment, nociceptive, neuropathic, and/or inflammatory pain.
Opioids are commonly used to manage cancer pain. However, opioids can be associated with several severe side effects, including sweating, constipation, dry mouth, nausea and vomiting, and sedation. Less commonly, opioids can also be associated with respiratory depression, pruritus, decreased testosterone levels, opioid-induced neurotoxicity, and opioid-induced endocrinopathy. Driver said that methadone is a longer acting opioid that is ideal in cancer pain management due to its potency. However, methadone can be hard to prescribe due to the drug’s long elimination half-life and associated cardiac issues.
Fentayl is another option for the treatment of breakthrough pain and is available in various forms including tablet, spray, lozenge, film, and sublingual tablets. Driver recommended rotating among opioids and fentanyl formulations, as some approaches may be better suited for each patient’s particular needs.