Classification of pain in cancer patients--a systematic literature review

Metabolic underpinnings of cancer-related fatigue

Cancer-related fatigue (CRF) is one of the most prevalent and detrimental complications of cancer. Emerging evidence suggests that obesity and insulin resistance are associated with CRF occurrence and severity in cancer patients and survivors. In this narrative review, we analyzed recent studies including both preclinical and clinical research on the relationship between obesity and/or insulin resistance and CRF. We also describe potential mechanisms for these relationships, though with the caveat that because the mechanisms underlying CRF are incompletely understood, the mechanisms mediating the association between obesity/insulin resistance and CRF are similarly incompletely delineated. The data suggest that, in addition to their effects to worsen CRF by directly promoting tumor growth and metastasis, obesity and insulin resistance may also contribute to CRF by inducing chronic inflammation, neuroendocrinological disturbance, and metabolic alterations. Furthermore, studies suggest that patients with obesity and insulin resistance experience more cancer-induced pain and are at more risk of emotional and behavioral disruptions correlated with CRF. However, other studies implied a potentially paradoxical impact of obesity and insulin resistance to reduce CRF symptoms. Despite the need for further investigation utilizing interventions to directly elucidate the mechanisms of cancer-related fatigue, current evidence demonstrates a correlation between obesity and/or insulin resistance and CRF, and suggests potential therapeutics for CRF by targeting obesity and/or obesity-related mediators.

Targeting TRPV1 for Cancer Pain Relief: Can It Work?

Chronic intractable pain affects a large proportion of cancer patients, especially those with metastatic bone disease. Blocking sensory afferents for cancer pain relief represents an attractive alternative to opioids and other drugs acting in the CNS in that sensory nerve blockers are not addictive and do not affect the mental state of the patient. A distinct subpopulation of sensory afferents expresses the capsaicin receptor TRPV1. Intrathecal resiniferatoxin, an ultrapotent capsaicin analog, ablates TRPV1-expressing nerve endings exposed to the cerebrospinal fluid, resulting in permanent analgesia in women with cervical cancer metastasis to the pelvic bone. High-dose capsaicin patches are effective pain killers in patients with chemotherapy-induced peripheral neuropathic pain. However, large gaps remain in our knowledge since the mechanisms by which cancer activates TRPV1 are essentially unknown. Most important, it is not clear whether or not sensory denervation mediated by TRPV1 agonists affects cancer progression. In a murine model of breast cancer, capsaicin desensitization was reported to accelerate progression. By contrast, desensitization mediated by resiniferatoxin was found to block melanoma growth. These observations imply that TRPV1 blockade for pain relief may be indicated for some cancers and contraindicated for others. In this review, we explore the current state of this field and compare the analgesic potential of TRPV1 antagonism and sensory afferent desensitization in cancer patients.

Cancer Pain Experience Through the Lens of Patients and Caregivers: Mixed Methods Social Media Study

BACKGROUND

Cancer pain represents a challenge for cancer patients and their family members. Despite progression in pain management, pain is still underreported and undertreated, and there is limited information on the related needs that patients and caregivers may have. Online platforms represent a fundamental tool for research to reveal the unmet needs of these users and their emotions outside the medical setting.

OBJECTIVE

This study aimed to (1) reveal the unmet needs of both patients and caregivers and (2) detect the emotional activation associated with cancer pain by analyzing the textual patterns of both users.

METHODS

A descriptive and quantitative analysis of qualitative data was performed in RStudio v.2022.02.3 (RStudio Team). We analyzed 679 posts (161 from caregivers and 518 from patients) published over 10 years on the "cancer" subreddit of Reddit to identify unmet needs and emotions related to cancer pain. Hierarchical clustering, and emotion and sentiment analysis were conducted.

RESULTS

The language used for describing experiences related to cancer pain and expressed needs differed between patients and caregivers. For patients (agglomerative coefficient=0.72), the large cluster labeled unmet needs included the following clusters: (1A) reported experiences, with the subclusters (a) relationship with doctors/spouse and (b) reflections on physical features; and (1B) changes observed over time, with the subclusters (a) regret and (b) progress. For caregivers (agglomerative coefficient=0.80), the main clusters were as follows: (1A) social support and (1B) reported experiences, with the subclusters (a) psychosocial challenges and (b) grief. Moreover, comparison between the 2 groups (entanglement coefficient=0.28) showed that they shared a common cluster labeled uncertainty. Regarding emotion and sentiment analysis, patients expressed a significantly higher negative sentiment than caregivers (z=-2.14; P<.001). On the contrary, caregivers expressed a higher positive sentiment compared with patients (z=-2.26; P<.001), with trust (z=-4.12; P<.001) and joy (z=-2.03; P<.001) being the most prevalent positive emotions.

CONCLUSIONS

Our study emphasized different perceptions of cancer pain in patients and caregivers. We revealed different needs and emotional activations in the 2 groups. Moreover, our study findings highlight the importance of considering caregivers in medical care. Overall, this study increases knowledge about the unmet needs and emotions of patients and caregivers, which may have important clinical implications in pain management.

Towards precision pain medicine for pain after cancer: the Cancer Pain Phenotyping Network multidisciplinary international guidelines for pain phenotyping using nociplastic pain criteria

Pain after cancer remains underestimated and undertreated. Precision medicine is a recent concept that refers to the ability to classify patients into subgroups that differ in their susceptibility to, biology, or prognosis of a particular disease, or in their response to a specific treatment, and thus to tailor treatment to the individual patient characteristics. Applying this to pain after cancer, the ability to classify post-cancer pain into the three major pain phenotypes (i.e. nociceptive, neuropathic, and nociplastic pain) and tailor pain treatment accordingly, is an emerging issue. This is especially relevant because available evidence suggests that nociplastic pain is present in an important subgroup of those patients experiencing post-cancer pain. The 2021 International Association for the Study of Pain (IASP) clinical criteria and grading system for nociplastic pain account for the need to identify and correctly classify patients according to the pain phenotype early in their treatment. These criteria are an important step towards precision pain medicine with great potential for the field of clinical oncology. Within this framework, the Cancer Pain Phenotyping (CANPPHE) Network, an international and interdisciplinary group of oncology clinicians and researchers from seven countries, applied the 2021 IASP clinical criteria for nociplastic pain to the growing population of those experiencing post-cancer pain. A manual is provided to allow clinicians to differentiate between predominant nociceptive, neuropathic, or nociplastic pain after cancer. A seven-step diagnostic approach is presented and illustrated using cases to enhance understanding and encourage effective implementation of this approach in clinical practice.

Advanced Adrenocortical Carcinoma: From Symptoms Control to Palliative Care

The prognosis of patients with advanced adrenocortical carcinoma (ACC) is often poor: in the case of metastatic disease, five-year survival is reduced. Advanced disease is not a non-curable disease and, in referral centers, the multidisciplinary approach is the standard of care: if a shared decision regarding several treatments is available, including the correct timing for the performance of each one, overall survival is increased. However, many patients with advanced ACC experience severe psychological and physical symptoms secondary to the disease and the cancer treatments. These symptoms, combined with existential issues, debase the quality of the remaining life. Recent strong evidence from cancer research supports the early integration of palliative care principles and skills into the advanced cancer patient's trajectory, even when asymptomatic. A patient with ACC risks quickly suffering from symptoms/effects alongside the disease; therefore, early palliative care, in some cases concurrent with oncological treatment (simultaneous care), is suggested. The aims of this paper are to review current, advanced ACC approaches, highlight appropriate forms of ACC symptom management and suggest when and how palliative care can be incorporated into the ACC standard of care.

Cancer pain: Results of a prospective study on prognostic indicators of pain intensity including pain syndromes assessment

BACKGROUND

Pain is a prevalent symptom in patients with advanced cancer. Recognition of prognostic factors associated with pain intensity, could help provide better assessment, leading to better pain management.

AIM

identifying prognostic factors which could guide improvements on cancer pain classification.

DESIGN

a prospective observational study on chronic cancer pain, exploring the association between average mean pain intensity during a 28 days study follow-up and patients' clinical and pain-related characteristics, including pain syndromes. To evaluate these associations, a mixed model was built.

SETTING/PARTICIPANTS

Patients attending a Palliative Care and Pain Outpatient Clinic from May 2015 to June 2019 were screened. Patients with moderate to severe cancer pain who were already receiving or needed treatment with third step WHO ladder opioids were enrolled in the study. Data from 342 patients with at least one follow-up visit were analyzed.

RESULTS

Pain intensity decreased significantly for all patients during time (p < 0.001). Age, sex, emotional distress, pain duration and neuropathic pain presence evaluated by the Douleur Neuropathique 4 Questions (DN4) questionnaire were not significantly associated to pain intensity. Breakthrough/episodic pain was associated with higher pain intensity during follow-up (p < 0.001). The diagnosis of pain syndrome was overall significantly associated with mean pain intensity during follow-up (p = 0.016). Particularly, the concurrent presence of visceral and soft (p = 0.026) or soft and nervous tissue pain (p = 0.043) were significantly related to worse outcome, whereas pain due to only soft tissue damage with better outcome (p = 0.032).

CONCLUSIONS

The recognition of specific pain syndromes may help to better classify cancer pain.

Predictors of Opioid Resistance: An Investigation in Cancer Pain

Appropriate use of opioid analgesics according to the World Health Organization pain relief ladder has provided pain relief to many patients with cancer pain. However, a proportion of patients fail to achieve sufficient pain relief and develop opioid resistance. Individual risk factors may relate to opioid resistance. Therefore, we conducted a historical cohort study to identify risk factors for opioid resistance and to construct an index to predict it. We investigated salient factors at the time of opioid initiation in the medical records of 233 patients. The outcome was the achievement of stable pain at 14 days after opioid introduction. We identified factors contributing to opioid resistance by multivariate analysis (p < 0.05). We created a resistance score from the regression equation of the identified factors to predict opioid resistance. Forty-nine (21.0%) patients were opioid resistant without achieving the outcome. Age, neuropathic pain, and alkaline phosphatase were extracted as significant factors for opioid resistance (p < 0.05). A resistance score was created from these factors and classified into binary values, the sensitivity was 80.6% and the negative predictive value was 91.6%. The findings suggest that the resistance score could be a sensitive predictor of opioid resistance before opioid initiation.

Patient Perspective on the Management of Cancer Pain in Spain

Pain in cancer is often underdiagnosed and undertreated. Breakthrough pain, in particular, severely impacts the quality of life of patients. In this study, we evaluated management and care of pain in Spain from the patient perspective by assessing the experience of 275 patients who had suffered breakthrough pain. Although most patients had suffered moderate-to-severe pain in the last 24 hours, pain relief was achieved in the majority of cases. The body areas with a higher pain intensity was felt varied based on primary cancer. Adherence to treatment was subpar, and patients were moderately concerned about addiction to treatment and adverse events. Doctors did not assess pain in every visit and there is room for improvement in its classification. Education strategies directed toward patients and health care personnel are needed to improve pain assessment, follow-up, and compliance. These could guide shared decision-making and improve communication about cancer pain to improve its care.

Cancer-Related Pain: A Longitudinal Study of Time to Stable Pain Control and Its Clinicodemographic Predictors

CONTEXT

Multidimensional assessment is pivotal in managing cancer-related pain.

OBJECTIVES

The objectives of this study were to determine time to stable pain control (SPC) and identify its baseline clinicodemographic predictors in patients with cancer pain.

METHODS

This is a prospective longitudinal study of patients attending a cancer pain clinic. Scheduled clinic attendances and weekly investigator-led phone calls enabled monitoring of patients' daily pain diary, opioid use, and other analgesic interventions. Baseline clinicodemographic variables were examined in survival analyses, which included the construction of accelerated failure time models with time ratios [TRs, (95% CIs)], based on time to SPC (pain intensity ≤3 and <3 breakthrough opioid doses over three consecutive days) for variable categories.

RESULTS

Of 319 participants, 22 died before achieving SPC and were censored in the survival analysis. The median survival time (95% CI) to SPC was 22 (19-25) days. In multivariable analysis, compared to their respective reference categories, female sex (P = 0.001), substance abuse (P < 0.001), a neuropathic pain component (P < 0.001), and use of ≥1 adjuvant analgesic (P = 0.022) each had TRs > 1 (1.03-2.54), whereas soft tissue pain (P < 0.001) had a TR = 0.71 (0.62-0.82), reflecting longer and shorter time to SPC, respectively.

CONCLUSION

SPC is achievable for most patients with cancer pain. Recognition of strong predictors of time to SPC, such as substance abuse, a neuropathic pain component, soft tissue pain, and current use of adjuvant analgesia, may help to triage care services based on therapeutic need and guide analgesic interventions.

Development of EirV3: A Computer-Based Tool for Patient-Reported Outcome Measures in Cancer

PURPOSE

Immediate transfer of patient-reported outcome measures (PROMs) for use in medical consultations is facilitated by electronic assessments. We aimed to describe the rationale and development of Eir version 3 (EirV3), a computer-based symptom assessment tool for cancer, with emphasis on content and user-friendliness.

METHODS

EirV3's specifications and content were developed through multiprofessional, stepwise, and iterative processes (from 2013 to 2016), with literature reviews on traditional and electronic assessment and classification methods, formative iterative usability tests with end-users, and assessment of patient preferences for paper versus electronic assessments.

RESULTS

EirV3 has the following two modules: Eir-Patient for PROMs registration on tablets and Eir-Doctor for presentation of PROMs in a user-friendly interface on computers. Eir-Patient starts with 19 common cancer symptoms followed by specific, in-depth questions for endorsed symptoms. The pain section includes a body map for pain location and intensity, whereas physical functioning, nutritional intake, and well-being are standard questions for all. Data are wirelessly transferred to Eir-Doctor. Symptoms with intensity scores ≥ 3 (on a 0 to 10 scale) are marked in red, with brighter colors corresponding to higher intensity, and supplemented with graphs displaying symptom development over time. Usability results showed that patients and health care providers found EirV3 to be intuitive, easy to use, and relevant. When comparing PROM assessments on paper versus tablets (n = 114), 19% of patients preferred paper, 41% preferred tablets, and 40% had no preference. Median intraclass correlation coefficient between paper and tablets (0.815) was excellent.

CONCLUSION

Iterative test rounds followed by continuous improvements led to a user-friendly, applicable symptom assessment tool, EirV3, developed for and by end-users. EirV3 is undergoing international testing of clinical and cross-cultural adaptability.

Cancer Pain Assessment and Classification

More than half of patients affected by cancer experience pain of moderate-to-severe intensity, often in multiple sites, and of different etiologies and underlying mechanisms. The heterogeneity of pain mechanisms is expressed with the fluctuating nature of cancer pain intensity and clinical characteristics. Traditional ways of classifying pain in the cancer population include distinguishing pain etiology, clinical characteristics related to pain and the patient, pathophysiology, and the use of already validated classification systems. Concepts like breakthrough, nociceptive, neuropathic, and mixed pain are very important in the assessment of pain in this population of patients. When dealing with patients affected by cancer pain it is also very important to be familiar to the characteristics of specific pain syndromes that are usually encountered. In this article we review methods presently applied for classifying cancer pain highlighting the importance of an accurate clinical evaluation in providing adequate analgesia to patients.

Standards for the management of cancer-related pain across Europe-A position paper from the EFIC Task Force on Cancer Pain

BACKGROUND AND OBJECTIVE

Pain is a common symptom in patients who survive cancer and in those who live with progressive advanced disease. Evidence from meta-analyses suggests that pain remains poorly controlled for a large proportion of patients; barriers to good management include poor assessment of pain, inadequate support for patient self-management and late or inadequate access to strong opioid analgesia in those with advanced disease.

METHODS

The European Pain Federation (EFIC) established a Task Force in 2017 which convened a European group of experts, drawn from a diverse range of relevant clinical disciplines, to prepare a position paper on appropriate standards for the management of cancer-related pain. The expert panel reviewed the available literature and made recommendations using the GRADE system to combine quality of evidence with strength of recommendation. The panel took into account the desirable and undesirable effects of the management recommendation, including the cost and inconvenience of each when deciding the recommendation.

RESULTS AND CONCLUSIONS

The 10 standards presented are aimed to improve cancer pain management and reduce variation in practice across Europe. The Task Force believes that adoption of these standards by all 37 countries will promote the quality of care of patients with cancer-related pain and reduce unnecessary suffering.

SIGNIFICANCE

Pain affects up to 40% of cancer survivors and affects at least 66% of patients with advanced progressive disease, many of whom experience poor pain control. These 10 standards are aimed to improve cancer pain management, promote the quality of care of patients and reduce variation across Europe.

A cross-sectional, comparative, syndromic description of oncological mixed pain in Medical Oncology units in Spain

OBJECTIVE

The reason cancer pain remains prevalent and hard to classify may be partially explained by the failure to identify neuropathic mechanisms. The objective of this research was to identify the syndromes of cancer pain that may be particularly hard to manage due to their mixed pathophysiology.

DESIGN

A series of 384 patients who had cancer of any type, at any stage, and suffered from chronic pain (symptom onset > 3 months) were assessed during a routine return visit in Spain. Medical oncologists indicated the presence and pathophysiology of 33 predefined pain syndromes on a per-patient basis. This information was then measured against clinical, psychosocial, and health care-related data to determine which syndromes pose particular challenges.

RESULTS

The mean (standard deviation) age of patients was 61.6 (12.6) years, 49.7% were women. Most (82%) had advanced metastatic disease, 68.7% were on second-line or palliative therapies. The worst syndrome was nociceptive, pure neuropathic, and mixed in 34.6, 26.9, and 38.6% of patients, respectively. Any syndrome could be of mixed pathophysiology. Only 10 syndromes were common (≥ 5% of patients). Syndromes related to malignant bone pain and involvement of chest wall structures were the most frequent. Certain syndromes (including tumor-related bone pain, chemotherapy-induced peripheral neuropathies, paraneoplastic pain syndromes, and malignant neuralgias or injury to cranial nerves) can be particularly challenging when they have a mixed pathophysiology, because the neuropathic component is rarely or unevenly considered.

CONCLUSIONS

Virtually all cancer pain syndromes can present mixed pathophysiology. Certain syndromes can include neuropathic components that are frequently overlooked.

What is stable pain control? A prospective longitudinal study to assess the clinical value of a personalized pain goal

BACKGROUND

A universal consensus regarding standardized pain outcomes does not exist. The personalized pain goal has been suggested as a clinically relevant outcome measure.

AIM

To assess the feasibility of obtaining a personalized pain goal and to compare a clinically based personalized pain goal definition versus a research-based study definition for stable pain.

DESIGN

Prospective longitudinal descriptive study.

MEASURES

The attending physician completed routine assessments, including a personalized pain goal and the Edmonton Classification System for Cancer Pain, and followed patients daily until stable pain control, death, or discharge. Stable pain for cognitively intact patients was defined as pain intensity less than or equal to desired pain intensity goal (personalized pain goal definition) or pain intensity ⩽3 (Edmonton Classification System for Cancer Pain study definition) for three consecutive days with <3 breakthroughs per day.

SETTING/PARTICIPANTS

A total of 300 consecutive advanced cancer patients were recruited from two acute care hospitals and a tertiary palliative care unit.

RESULTS

In all, 231/300 patients (77%) had a pain syndrome; 169/231 (73%) provided a personalized pain goal, with 113/169 (67%) reporting a personalized pain goal ⩽3 (median = 3, range = 0-10). Using the personalized pain goal definition as the gold standard, sensitivity and specificity of the Edmonton Classification System for Cancer Pain definition were 71.3% and 98.5%, respectively. For mild (0-3), moderate (4-6), and severe (7-10) pain, the highest sensitivity was for moderate pain (90.5%), with high specificity across all three categories (95%-100%).

CONCLUSION

The personalized pain goal is a feasible outcome measure for cognitively intact patients. The Edmonton Classification System for Cancer Pain definition closely resembles patient-reported personalized pain goals for stable pain and would be appropriate for research purposes. For clinical pain management, it would be important to include the personalized pain goal as standard practice.

Modern pain neuroscience in clinical practice: applied to post-cancer, paediatric and sports-related pain

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Generalized hypersensitivity in post-cancer, sports-related and pediatric pain.

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Rationale for pain education, stress management and cognition targeted exercises.

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Need to change from a biomedical or psychosocial to an integrated approach.

In the last decade, evidence regarding chronic pain has developed exponentially. Numerous studies show that many chronic pain populations show specific neuroplastic changes in the peripheral and central nervous system. These changes are reflected in clinical manifestations, like a generalized hypersensitivity of the somatosensory system. Besides a hypersensitivity of bottom-up nociceptive transmission, there is also evidence for top-down facilitation of pain due to malfunctioning of the endogenous descending nociceptive modulatory systems. These and other aspects of modern pain neuroscience are starting to be applied within daily clinical practice. However, currently the application of this knowledge is mostly limited to the general adult population with musculoskeletal problems, while evidence is getting stronger that also in other chronic pain populations these neuroplastic processes may contribute to the occurrence and persistence of the pain problem. Therefore, this masterclass article aims at giving an overview of the current modern pain neuroscience knowledge and its potential application in post-cancer, paediatric and sports-related pain problems.

Latin-American guidelines for cancer pain management

Cancer is a major public health issue. Poor pain management has devastating consequences that seriously affect quality of life, diminish functionality and place a huge emotional burden on patients and their relatives. A group of Latin American opinion leaders were invited to participate in a meeting to discuss areas associated with cancer pain. The expert panel reviewed the latest literature to draft region-specific guidelines for effective pain management. The guidelines make recommendations on tailoring treatment to the specific type of pain and provide local physicians with the state-of-the art findings in the field. Management should be with pharmacological approaches (nonopioid, adjuvant and opioid analgesics, as well as oncologic therapies and interventional procedures) and nonpharmacological approaches.

Differences in demographic, clinical, and symptom characteristics and quality of life outcomes among oncology patients with different types of pain

The purposes of this study, in oncology outpatients receiving chemotherapy (n = 926), were to: describe the occurrence of different types of pain (ie, no pain, only noncancer pain [NCP], only cancer pain [CP], or both CP and NCP) and evaluate for differences in demographic, clinical, and symptom characteristics, and quality of life (QOL) among the 4 groups. Patients completed self-report questionnaires on demographic and symptom characteristics and QOL. Patients who had pain were asked to indicate if it was or was not related to their cancer or its treatment. Medical records were reviewed for information on cancer and its treatments. In this study, 72.5% of the patients reported pain. Of the 671 who reported pain, 21.5% reported only NCP, 37.0% only CP, and 41.5% both CP and NCP. Across the 3 pain groups, worst pain scores were in the moderate to severe range. Compared with the no pain group, patients with both CP and NCP were significantly younger, more likely to be female, have a higher level of comorbidity, and a poorer functional status. In addition, these patients reported: higher levels of depression, anxiety, fatigue, and sleep disturbance; lower levels of energy and attentional function; and poorer QOL. Patients with only NCP were significantly older than the other 3 groups. The most common comorbidities in the NCP group were back pain, hypertension, osteoarthritis, and depression. Unrelieved CP and NCP continue to be significant problems. Oncology outpatients need to be assessed for both CP and NCP conditions.

Characteristics of breakthrough cancer pain and its influence on quality of life in an international cohort of patients with cancer

OBJECTIVES

Breakthrough cancer pain (BTP) represents a treatment challenge. Objectives were to examine the prevalence and characteristics of BTP in an international sample of patients with cancer, and to investigate the relationship between BTP and quality of life (QoL).

METHODS

This was an observational cross-sectional multicentre study. Participating patients completed self-report questionnaires on a touch-screen laptop computer, including the Brief Pain Inventory, Alberta Breakthrough Pain Assessment Tool (ABPAT) and European Organisation for Research and Treatment of Cancer 30-item Core Quality of Life Questionnaire (EORTC QLQ-C30). The study was performed in 17 centres in 8 countries and involved 4 languages (Norwegian, Italian, German and English).

RESULTS

Records from a convenience sample of 978 patients with advanced cancer were analysed; mean age was 62.2 years, 48.3% were women and 84.4% had metastatic disease. A total of 296 patients (30%) had no pain, defined as worst pain in the past 24 hours <1 on a 0-10 scale. Of the 682 patients with a pain score ≥1, 393 (58%) reported no BTP on the screening item, while 289 (30%) confirmed flare ups of BTP. Patients with BTP reported significantly higher pain intensity scores (<0.001) than patients without BTP; 57.1% of patients rated BTP at its worst as being severe: ≥7 on a 0-10 scale. Time from onset to peak intensity was <10 min for 42.9%, and average time to pain relief was 27.1 min. BTP was commonly triggered by medication wearing off (28%). Patients with BTP had significantly worse mean outcomes on 10 of 15 functional and symptom scales of the EORTC QLQ-C30 (<0.001). Severe pain intensity in the last week was a powerful predictor of BTP (OR 4.1) and poor QoL (OR 1.9).

CONCLUSIONS

BTP is highly prevalent with prolonged episodes despite analgaesics, and has a pervasive impact on QoL. Patients reporting high pain intensity should be carefully evaluated for BTP and efficacy of analgaesic treatment, to provide optimal pain management and improve QoL.

TRIAL REGISTRATION NUMBER

NCT00972634; Results.

Pain following cancer treatment: Guidelines for the clinical classification of predominant neuropathic, nociceptive and central sensitization pain

BACKGROUND

In addition to fatigue, pain is the most frequent persistent symptom in cancer survivors. Clear guidelines for both the diagnosis and treatment of pain in cancer survivors are lacking. Classification of pain is important as it may facilitate more specific targeting of treatment. In this paper we present an overview of nociceptive, neuropathic and central sensitization pain following cancer treatment, as well as the rationale, criteria and process for stratifying pain classification.

MATERIAL AND METHODS

Recently, a clinical method for classifying any pain as either predominant central sensitization pain, neuropathic or nociceptive pain was developed, based on a large body of research evidence and international expert opinion. We, a team of 15 authors from 13 different centers, four countries and two continents have applied this classification algorithm to the cancer survivor population.

RESULTS

The classification of pain following cancer treatment entails two steps: (1) examining the presence of neuropathic pain; and (2) using an algorithm for differentiating predominant nociceptive and central sensitization pain. Step 1 builds on the established criteria for neuropathic pain diagnosis, while Step 2 applies a recently developed clinical method for classifying any pain as either predominant central sensitization pain, neuropathic or nociceptive pain to the cancer survivor population.

CONCLUSION

The classification criteria allow identifying central sensitization pain following cancer treatment. The recognition of central sensitization pain in practice is an important development in the integration of pain neuroscience into the clinic, and one that is relevant for people undergoing and following cancer treatment.

Agreement between personally generated areas of quality of life concern and standard outcome measures in people with advanced cancer

PURPOSE

People with advanced cancer experience different sequelae which have unique effects on quality of life (QOL). The patient-generated index (PGI) is a personalized measure that allows patients to nominate, rate, and value areas that have the most impact on QOL. Fatigue, pain, and aspects of physical function are among the top 10 areas with QOL impact. An area of validation that is lacking for the PGI is the extent to which spontaneously nominated areas of QOL that patients are concerned with, agree with ratings obtained from standard patient reported outcomes (PROs).

METHODS

Data from 192 patients were used to compare ratings on fatigue, pain, and physical function obtained from PGI to those from standard outcome measures.

RESULTS

Within one severity rating, agreement ranged from 32.1 to 76.9 % within the fatigue domain, 34.2 to 95.24 % for pain, and between 84.2 and 94.7 % for physical function. Of the 10 items where the PGI had the highest agreement, 7 came from the RAND-36. At the domain level, people nominating an area scored in the more impaired range on standard measures than people who did not.

CONCLUSION

PGI gives comparable information as do standard measures.

IMPLICATIONS FOR CANCER

PGI provides important information to guide clinical care of the patient and also produces a legitimate total score suitable for research.

Characteristics and associations of pain intensity in patients referred to a specialist cancer pain clinic

Uncontrolled cancer pain (CP) has the ability to impair quality of life and interfere with daily activities. Poor CP management is consistently attributed to inadequate assessment and clarification of pain. The authors of this study identified the need to understand the nature of CP and inform evidence-based strategies for its assessment and management. The study aimed to describe the characteristics of CP and to determine predictors of pain intensity with patients referred to a CP clinic in Portugal.

BACKGROUND:

Uncontrolled cancer pain (CP) may impair quality of life. Given the multidimensional nature of CP, its poor control is often attributed to poor assessment and classification.

OBJECTIVES:

To determine the characteristics and associations of pain intensity in a specialist CP clinic.

METHODS:

Consecutive patients referred to the CP clinic of the Portuguese Cancer Institute (Lisbon, Portugal) had standardized initial assessments and status documentation of the following: Brief Pain Inventory ratings for ‘pain now’ as the outcome variable; initial pain intensity (iPI) on a 0 to 10 scale; pain mechanism (using the Douleur Neuropathique 4 tool to assess neuropathic pain); episodic pain; Eastern Cooperative Oncology Group rating; oral morphine equivalent daily dose (MEDD); Hospital Anxiety Depression Scale and Emotional Thermometer scores; and cancer diagnosis, metastases, treatment and pain duration. Univariable analyses were conducted to test the association of independent variables with iPI. Variables with P<0.1 were entered into a multivariable regression model, using backward elimination and a cut-point of P=0.2 for final model selection.

RESULTS:

Of 371 participants, 285 (77%) had moderate (4 to 6) or severe (7 to 10) iPI. The initial median MEDD was relatively low (30 mg [range 20 mg to 60 mg]). In the multivariable model, higher income, Eastern Cooperative Oncology Group rating 3 to 4, cancer diagnosis (head and neck, genitourinary and gastrointestinal), adjuvant use and initial MEDD were associated with iPI (P<0.05). The model’s R² was 18.6, which explained only 19% of iPI variance.

CONCLUSIONS:

The diversity of factors associated with pain intensity and their limited explanation of its variance underscore the biopsychosocial complexity of CP. Adequacy of CP management warrants further exploration.

Pain management of the cancer patient

INTRODUCTION

Cancer pain is one of the most important symptoms of malignant disease, which has a major impact on the quality of life of cancer patients. Therefore, it needs to be treated appropriately after a careful assessment of the types and causes of pain.

AREAS COVERED

The mainstay of cancer pain management is systemic pharmacotherapy. This is, in principle, still based on the WHO guidelines initially published in 1986. Although these have been validated, they are not evidence-based. The principles are a stepladder approach using non-opioids, weak and then strong opioids. In addition, adjuvants can be added at any step to address specific situations such as bone or neuropathic pain. Patients, even if they are on long-acting opioids, need to be provided with immediate-release opioids for breakthrough pain. In case of inefficacy or severe adverse effects of one opioid, rotation to another opioid is recommended.

EXPERT OPINION

There is a major need for more and better randomized controlled trials in the setting of cancer pain as the lack of evidence is hampering the improvement of current treatment guidelines.

The routine use of the Edmonton Classification System for Cancer Pain in an outpatient supportive care center

Objective:

There is no standardized and universally accepted pain classification system for the assessment and management of cancer pain in both clinical practice and research studies. The Edmonton Classification System for Cancer Pain (ECS–CP) is an assessment tool that has demonstrated value in assessing pain characteristics and response. The purpose of our study was to determine the relationship between negative ECS–CP features and some pain-related variables like pain intensity and opioid use. We also explored whether the number of negative ECS–CP features was associated with higher pain intensity.

Method:

The electronic charts of 100 patients at an outpatient supportive care clinic in a comprehensive cancer center were reviewed for variables like patient characteristics, initial ECS–CP assessment, morphine equivalent daily dose (MEDD), opioid rotation, Edmonton Symptom Assessment Score (ESAS), and use of adjuvant analgesics.

Results:

Some 91 of the 100 charts were eligible for analysis. The most common primary cancer type was gastrointestinal (22.1%). The median pain intensity was 6, and the median MEDD was 45 mg. Neuropathic pain was associated with higher median pain intensity (7 vs. 5, p = 0.007) and median MEDD requirement (83 vs. 30, p = 0.013). Psychological distress was associated with higher median pain intensity (7 vs. 5, p = 0.042). Incident pain was also associated with a trend toward higher pain intensity (6 vs. 5, p = 0.06). A higher number of negative ECS–CP features was associated with higher pain intensity (p = 0.01).

Significance of Results:

The ECS–CP was successfully completed in the majority of patients, demonstrating its utility in routine clinical practice. Neuropathic pain and psychological distress were associated with higher pain intensity. Also, neuropathic pain was associated with a higher MEDD. A higher sum of negative ECS–CP features was associated with higher pain intensity. Further studies will be needed to verify and explore these observations.

Pain: a descriptive study in patients with cancer

Ninety percent of patients with advanced cancer are reported to experience pain at some time during the course of their illness. This pain usually is improperly evaluated because it varies by patient and is difficult to control. Pain often cannot be conceptualized because of the individual nature of patient experience; however, patterns of pain occur in those suffering from similar conditions. This secondary analysis was conducted to examine the characteristics of pain in individuals with advanced cancer. The sample consisted of 717 patients with cancer who were receiving hospice home care in the southeastern United States. An understanding of the total pain experience, including type of pain and pain location, is important for addressing pain in patients with cancer in hospice care. More effective strategies are needed for pain management in this patient population. In addition, steps need to be taken to ensure that hospice care is understood by and made available to minorities.

Pain management for the cancer patient - current practice and future developments

Anaesthesiologists will be asked to provide pain management for cancer patients in the absence of more specialised services, when interventional techniques are indicated and in the postoperative period. In all these settings, the complexity of cancer pain and its psychosocial connotations need to be considered to provide appropriate and holistic care. Principles of systemic pain management, effective in most patients, continue to follow established guidelines; identification of neuropathic pain and its appropriate treatment is important here. Interventional pain relief is required in a minority of cancer patients, but it should be considered when appropriate and then done with best available expertise. Neurolytic procedures have lost importance here over the years. Postoperative pain management should be multimodal with consideration of regional techniques when applicable. In managing postoperative pain in cancer patients, opioid tolerance needs to be addressed to avoid withdrawal and poor analgesia. Preventive techniques aiming to reduce chronic postoperative pain should be considered.

Patients attended by palliative care teams: are they always comparable populations?

Patients attended by palliative care teams: are they always comparable populations? To answer this question we have compared the basic epidemiological characteristics of patients attended by home palliative care teams (HPCT) in two autonomous regions of Spain. We carried out a coordinated analytical, observational and prospective study in two Spanish autonomous regions: Aragon and Catalonia. Data were kept during each home care visit according to patients' needs. Inclusion criteria were: advanced cancer, over 18 years old and first contact with a HPCT. The recruitment period was 6 months. Variables included were: Survival time (days), age, sex, primary disease and extension, place of residence. Functional and cognitive state, and co-morbidity. 10 signs/symptoms: asthenia, anorexia, cachexia, dysphagia, xerostomy, dyspnoea, oedemas, level of consciousness, presence of delirium, presence of pressure ulcers and some treatment data. Others variables considered were: responsible team, origin, destination when discharge, date and place of death, number of visits made and duration of monitoring. We developed a comparison between groups by Chi-squared test or the non-parametric Mann-Whitney U test and a survival analysis by Kaplan-Meier curves and the logrank test to determine differences between factors. The SPSS version 15.0 software package was used. 698 patients were included, 56.2% from Aragon and 43.8% from Catalonia. 60.3% were males, without differences between the regions. Characteristics relative to age, sex, place of residence and extension of oncological diseases were similar for both groups. We found significant differences between the two populations relative to survival time, co-morbidity, functional state, presence and intensity of a number of symptoms and the treatments, patient monitoring and the their destination after discharge. We can conclude that palliative care teams cover different profiles of patients with regard to their co-morbidity, functional, cognitive and symptomatic states. It must be pointed that the organization of palliative care services and their experience appears to condition the profile of patients they attend. There is a need of consensus on the basic descriptors for palliative care patients in order to ensure that results will be comparable.

Fixed-dose combinations for emerging treatment of pain

INTRODUCTION

Pain is a large and growing medical need that is not currently being fully met, primarily due to the shortcomings of existing analgesics (insufficient efficacy or limiting side-effects). Better outcomes might be achieved using a combination of analgesics. The ratio of the combinations matters and should therefore be evaluated using rigorous quantitative and well-documented analysis.

AREAS COVERED

Advances have been made in understanding the normal physiology of pain processing, including the pathways and neurotransmitters involved. Insight has also been gained about physiological processes that can lead to different 'types' of pain and the transition from acute to chronic pain conditions. This 'multimechanistic' nature of most pains is better matched using a 'multimechanistic' rather than 'monomechanistic' analgesic approach. Such an approach - and the experimental design and data analysis to assess optimal combinations - is described and discussed.

EXPERT OPINION

There are sound pharmacologic, as well as practical, reasons for using combinations of drugs to treat pain. Compared with single agents, they offer a potential better match to the underlying pain physiology and thus greater efficacy or reduced side effects. The optimal efficacy and side-effect ratio must be determined in a scientifically rigorous manner.

Cancer Pain: A Critical Review of Mechanism-based Classification and Physical Therapy Management in Palliative Care

Mechanism-based classification and physical therapy management of pain is essential to effectively manage painful symptoms in patients attending palliative care. The objective of this review is to provide a detailed review of mechanism-based classification and physical therapy management of patients with cancer pain. Cancer pain can be classified based upon pain symptoms, pain mechanisms and pain syndromes. Classification based upon mechanisms not only addresses the underlying pathophysiology but also provides us with an understanding behind patient's symptoms and treatment responses. Existing evidence suggests that the five mechanisms – central sensitization, peripheral sensitization, sympathetically maintained pain, nociceptive and cognitive-affective – operate in patients with cancer pain. Summary of studies showing evidence for physical therapy treatment methods for cancer pain follows with suggested therapeutic implications. Effective palliative physical therapy care using a mechanism-based classification model should be tailored to suit each patient's findings, using a biopsychosocial model of pain.

Utilization of brief pain inventory as an assessment tool for pain in patients with cancer: a focused review

The Pain Research Group of the world health organization (WHO) Collaborating Centre for Symptom Evaluation in Cancer Care had developed the Brief Pain Inventory (BPI), a pain assessment tool for use with cancer patients. The BPI measures both the intensity of pain (sensory dimension) and interference of pain in the patient's life (reactive dimension). The objective of this review paper was to provide a detailed update of existing evidence on applicability of BPI in evaluation of patients with cancer pain. The BPI demonstrated good construct and concurrent validity. It was translated and validated into many languages - Brazilian, Chinese, Greek, Hindi, Italian, Japanese, Korean, Malay, Norwegian, Polish, Russian, Spanish, Taiwanese and Thai. The BPI was validated in patient populations such as bone metastases, breast cancer and postoperative cancer patients. The BPI can be used both as a quantitative or a qualitative measure for statistical analysis. The BPI was a powerful tool and, having demonstrated both reliability and validity across cultures and languages, was being adopted in many countries for clinical pain assessment, epidemiological studies, and in studies on the effectiveness of pain treatment. Future studies are warranted on its responsiveness and cross-cultural adaptation into other cancer pain syndromes and into other Indian languages.

Reporting characteristics of cancer pain: a systematic review and quantitative analysis of research publications in palliative care journals

Objective:

A common disorder requiring symptom palliation in palliative and end-of-life care is cancer. Cancer pain is recognized as a global health burden. This paper sought to systematically examine the extent to which there is an adequate scientific research base on cancer pain and its reporting characteristics in the palliative care journal literature.

Materials and Methods:

Search conducted in MEDLINE and CINAHL sought to locate all studies published in 19 palliative/ hospice/ supportive/ end-of-life care journals from 2009 to 2010. The journals included were: American Journal of Hospice and Palliative Care, BMC Palliative Care, Current Opinion in Supportive and Palliative Care, End of Life Care Journal, European Journal of Palliative Care, Hospice Management Advisor, Indian Journal of Palliative Care, International Journal of Palliative Nursing, Internet Journal of Pain Symptom Control and Palliative Care, Journal of Pain and Palliative Care Pharmacotherapy, Journal of Palliative Care, Journal of Palliative Medicine, Journal of Social Work in End-of-life and Palliative Care, Journal of Supportive Oncology, Palliative Medicine, Palliative and Supportive Care, and Supportive Care in Cancer. Journal contents were searched to identify studies that included cancer pain in abstract.

Results:

During the years 2009 and 2010, of the selected 1,569 articles published in the journals reviewed, only 5.86% (92 articles) were on cancer pain.

Conclusion:

While researchers in the field of palliative care have studied cancer pain, the total percentage for studies is still a low 5.86%. To move the field of palliative care forward so that appropriate guidelines for cancer pain management can be developed, it is critical that more research be reported upon which to base cancer pain therapy in an evidence-based palliative care model.

[Neuropathic and tumour-induced headache: Therapeutic options]

Cancer pain in the field of otolaryngology can be effectively alleviated. Only very few questions regarding the patient's history of pain are required to understand the type of pain being dealt with and to be able to make the correct selection of analgetic agents. It is particularly important to treat tumor breakthrough pain appropriately, for which a sufficient number of therapeutic agents are available. The present article comments on the various possibilities of specific drugs and interventional therapeutic approaches, as well as their specific characteristics within the field of otolaryngology, supplemented with various tricks for their practical application. Using these basic rules, most problems can be identified and specific treatments optimized. The progression of cancer pain may show wide dynamic ranges, and the therapeutic approach should always be adjusted to the current situation. Palliative care of a cancer patient may be particularly challenging in that, not only the treatment of pain, but also the treatment of respiratory distress is of key importance.

European Palliative Care Research Collaborative pain guidelines: opioid switching to improve analgesia or reduce side effects. A systematic review

According to a Cochrane review on opioid switching, sound evidence on the practice of substituting one strong opioid with another to improve pain control and reduce adverse effects was lacking in 2004. A systematic search strategy was developed to include studies after 2004, with adult cancer patients switching between strong opioids and reporting estimates of effect on pain and adverse effects. The search retrieved 288 publications (71 duplicates); 187 abstracts and 19 full papers were excluded. Eleven papers met the inclusion criteria; none were randomized controlled trials/meta-analyses. Studies comprised 280 patients (group size 10-32). A variety of opioids and switching strategies were studied. Pain intensity was significantly reduced in the majority of studies. Serious adverse effects were improved. Due to serious design limitations, the level of evidence was low (D). Randomized trials, with standardization of cohort classification, use of outcomes and analysis are warranted to establish the practice of opioid switching.

Pitfalls in defining and quantifying cachexia

Cancer-related symptoms such cachexia and pain are subjects of a proliferation of assessment tools, diagnostic criteria, and systems for staging, which are notably disparate, and lack agreement on the variables to be measured. Teams of experts have worked diligently to develop consensus definitions of the terms cachexia and cancer cachexia, and these efforts provide the basis to develop agreement upon the measurements and tools that are applicable to the diagnosis and staging of cancer cachexia.

Can the global uptake of palliative care innovations be improved? Insights from a bibliometric analysis of the Edmonton Symptom Assessment System

Clinical research is undertaken to improve care for palliative patients, but little is known about how to support the broad uptake of resultant innovations. The objectives of this paper are to: (1) explore the uptake of the Edmonton Symptom Assessment System throughout the global palliative care community through the lens of a bibliometric review - a research method that maps out the journey of new knowledge uptake by evaluating where key articles are cited in published literature; (2) construct hypotheses on attributes of the global community of palliative care learners; and (3) make inferences on approaches that could improve knowledge transfer. While preliminary, results of the study suggest several specific approaches that could support widespread uptake of innovations in palliative care: targeting publication in high impact, international journals; explicitly focusing on how the innovation is applied to best practice; encouraging additional research to expand on early studies; consciously targeting key professional groups and organizations to promote discussion in the grey literature; and early translation and promotion within multiple languages.