Curr Pain Headache Rep (2014) 18:440 DOI 10.1007/s11916-014-0440-5
CANCER PAIN (D MARCUS, SECTION EDITOR)
Understanding the Cancer Pain Experience Judith A. Schreiber
Published online: 13 June 2014 # Springer Science+Business Media New York 2014
Abstract Cancer pain management is a major element of successful cancer survivorship. Regardless of where someone is along the cancer experience, from a newly diagnosed patient to long-term survivor, pain is a potential treatmentrelated effect that can have a significant impact on a survivor’s life. Quality pain management for cancer survivors is complicated by the fact that cancer-related pain can be due to the tumor, surgery, radiation, and/or chemotherapy. Additionally, the pain experience is related to many psychosocial/spiritual factors. Despite almost 40 years of attention devoted to improving cancer pain management, many cancer survivors are less than optimally treated, often owing to survivor and healthcare provider knowledge barriers. This article reviews some of the latest research related to cancer pain management treatment options, measurement/assessment, and interventions. Progress has been made in understanding new aspects of the pain experience, but more work is yet to be done. Keywords Cancer pain . Management . Survivorship . Treatment options . Intervention
Introduction Pain is one of the most frequently reported and studied cancerassociated treatment effectS [1–3], affecting up to 33 % of survivors after curative treatment. Effective management of cancer pain is essential to long-term quality of life. For survivors of cancer, pain is often complicated owing to multiple sources of pain, including tumor pain, postsurgical pain, and This article is part of the Topical Collection on Cancer Pain J. A. Schreiber (*) University of Louisville, School of Nursing, 555 S. Floyd St., Room 4057, Louisville, KY 40592, USA e-mail:
[email protected]
pain related to treatment modalities such as chemotherapy and radiation therapy. The type of pain experienced may be neuropathic, somatic, visceral and acute, chronic, or both [4, 5]. There are an estimated 13.7 million Americans alive with a history of cancer [3]. Based on this number and the estimated number of cancer survivors with chronic pain, there are approximately 4.5 million American cancer survivors who are coping with chronic pain. The percentage of cancer survivors reporting pain varies (up to 64 %) based on the stage of disease, early versus metastatic or end-stage [4]. A recent review of cancer pain management over the last 40 years identified vast changes in attitudes and knowledge about pain management, as well as significant changes in pharmacological and nonpharmacological options for pain control [6]. Back in the mid-1970s clinicians, patients, and families were concerned that narcotics might contribute to an earlier death, alter mental functioning, and lead to addiction. Originally, pain medications were only given as needed, rather than scheduled, as is more common currently. Much has been accomplished, with research advances in pain measurement and treatment. Moving forward, translating current knowledge into routine practice is a major area of focus. Another review of older adults with cancer focused on narrative reports and identified three areas affected by pain: emotional responses, effect on life and living, and how communication between the survivor and the clinician affected the pain experience [7]. There are many cross-sectional cancer pain management studies within the literature. These studies focus on what issues or activities are associated with improved or ineffectual cancer pain management. Fewer randomized controlled trials (RCTs) are conducted comparing various methods for improving cancer pain management other than specific drug trials. By examining the literature within the last year, 24 studies were found pertaining to cancer pain management (four reviews; five RCTs; 12 cross-sectional; three
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retrospective studies; one cohort study; and one qualitative study). This article will review the latest findings related to cancer pain management (Table 1).
Treatment Options Treatment for chronic cancer pain often presents difficulties when trying to balance optimal pain resolution and optimal mental and physical functioning [8]. As a result, new applications or formulations of existing pain medications have been prescribed for cancer pain in the recent past. Three of the most commonly prescribed “new” medications will be reviewed: ketamine, intravenous acetaminophen, and oral/nasal fentanyl. Ketamine Ketamine as a pain reliever, either alone or as an adjuvant therapy with opioids, has received a lot of attention in the last few years. A recent systematic review has examined ketamine use for adults and children with cancer [9••]. Although there are limitations to the strength of the evidence owing to the limited number of published studies and lack of long-term follow-up, the evidence does suggest that ketamine is a viable addition to the treatment options. The adult studies were more rigorous, while the pediatric data came from case reports and one small study. Another factor limiting conclusions was the variability in medication routes and dosages. Ketamine alone did not statistically improve pain control [10]; however, studies using ketamine with opioids did demonstrate a reduced need for the opioids [11]. Further research specifically focused on the optimal route and dosage, and conducted longitudinally is needed to support efficacy. Palliative care practice is an area in which novel use of medications for treating refractory side effects such as pain is initially attempted. An excellent overview of the pharmacological, intracellular/receptor responses, and review of current practices related to ketamine for cancer-associated and other syndromes of refractory pain concludes that ketamine is effective and opiod-sparing [12]. One significant caution is that psychotomimetic adverse effects are not uncommon but Table 1 Areas of cancer pain management research Treatment options Pain measurement
Interventions
• Healthcare provider perspective • Patient perspective • Effect of pain on physical/psychological functioning • Patient education • Pain management programs
respond well to haloperidol or other short-acting benzodiazepines. Another review by Soto et al. [13], concluded that use of oral ketamine produced no real decrease in pain level, but did result in a significant decrease in the amount of opiates used [13]. A small (n=20), placebo RCT did not find statistically significant differences between the two groups for analgesic effects, tolerability, and patient satisfaction [14]. Although potential rationales for the lack of difference were discussed, ultimately the combination of a small number of participants and short study duration (2 days) does not allow for any solid conclusions. Intravenous Acetaminophen Intravenous (IV) acetaminophen was developed to address postoperative pain when oral administration was not appropriate owing to nausea and vomiting. The IV formulation has been used internationally for a number of years, but was only approved for use in the USA in 2010. A systematic review of 16 studies reported that IV acetaminophen improved analgesia postsurgery and decreased opioid usage [15]. A systematic review focused on the addition of nonsteroidal anti-inflammatory drugs to the World Health Organization Pain Ladder Step III opioids [16]. Although there was weak support for the addition of the nonsteroidals, owing to improved analgesia and reduced opioid doses, there was insufficient data for adding paracetamol (acetaminophen) to Step III opioids. Current practice is to infuse 100 ml IV acetaminophen over 15 mins. The Baylor Medical System instituted a rapid infusion protocol with anesthesiologist monitoring. After the policy had been in place for 6 months, a retrospective chart review was performed (n=100). One patient was found with pain on infusion, no side effects of erythema at the injection site, and no slowing or discontinuation of the infusion (average time 3.4 mins). There were statistically significant differences in systolic and diastolic blood pressures that were not clinically relevant [systolic –4.31, 95 % confidence interval (CI) –5.84 to 2.78; diastolic –1.92, 95 % CI –3.37 to – 0.47; p50 % in 90.8 % of episodes. Webster et al. [24] reported a significantly greater pain intensity difference with buccal fentanyl over oral oxycodone (0.88 vs. 0.76, p1 year after surgery [33]. Survivors of breast cancer expected acute pain postsurgery but did not expect surgery-related chronic pain. These survivors identified a need for more information and communication, a responsibility to manage personally their pain, and discussed issues related to the effects of chronic pain on daily living, work, physical and social activities, and decreased quality of sleep. Knudsen et al. [34•] investigated patients’ ranking of pain domains, perceptions of their pain experience, and identified potential new pain domains. Study findings emphasized the consequences of pain on poor physical and psychological function, and added sleep issues as a pain domain.
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Patients Adherence to the pain regimen is an important factor in achieving good pain control. Yoong et al. [38] investigated adherence to long-acting opioids in an advanced lung cancer population. They reported that 28 % were nonadherent (p
