Pain prevalence and characteristics in survivors of solid cancers: a systematic review and meta-analysis

Myofascial pain syndrome in patients with cancer: a narrative review

PURPOSE

Myofascial pain syndrome (MPS) is a chronic musculoskeletal pain syndrome. The purpose of this review is to describe the epidemiological and treatment evidence and to address the future research agenda in patients with cancer.

METHODS

A narrative review of previous reports investigating the prevalence and treatment of MPS in the oncology field is presented. The target population is patients with cancer and cancer survivors.

RESULTS

There have been three prospective and two retrospective studies investigating the prevalence of MPS. MPS is as high as 38%-45% in patients with advanced or incurable cancer and 11.9%-44.8% in cancer survivors. A total of nine reports investigated the efficacy of the following interventions: trigger point injection (TPI), myofascial techniques and ischaemic compression. TPI has been reported to be effective in four observational studies. One randomised study reported the efficacy of myofascial techniques, but two randomised studies reported no added beneficial effects of it in breast cancer survivors. Two randomised studies investigated the efficacy of ischaemic compression, but the obtained results were contradictory.

CONCLUSIONS

MPS is highly prevalent. We should know that non-cancer pain is also common in both patients with cancer and survivors. In treating such pain, careful physical examination is essential. Then, non-pharmacological treatment should be considered as well as pharmacotherapy. As evidence regarding MPS in the oncology field is scarce, further research is warranted.

Household Income Is Associated with Chronic Pain and High-Impact Chronic Pain among Cancer Survivors: A Cross-Sectional Study Using NHIS Data

Pain is a prevalent issue among cancer patients, yet its link with socioeconomic status has not been thoroughly examined. This study investigated chronic pain (lasting ≥3 months) and high-impact pain (chronic pain limiting activities) among cancer survivors based on household income relative to the federal poverty level (FPL), using data from the National Health Interview Survey (2019-2020). Of the 4585 participants with a history of solid cancers, 1649 (36.3%) reported chronic pain and 554 (12.6%) reported high-impact chronic pain. After adjustment, participants with incomes < 200% FPL had significantly higher odds of chronic pain (adjusted odds ratio [aOR]: 1.60, 95% CI: 1.25-2.05) and high-impact chronic pain (aOR: 1.73, 95% CI: 1.09-2.74) compared to those with incomes ≥ 400% FPL. Opioid use for chronic pain was most prevalent among those with incomes < 200% FPL (28.3%) compared to those with 200-399% (21.3%) and ≥400% (19.0%). Higher-income participants reported greater use of alternative pain management methods such as yoga (50.5%), chiropractic care (44.8%), and physical therapy (44.3%). This study highlights the association between household income and chronic pain outcomes among cancer survivors, emphasizing the necessity for targeted interventions to mitigate healthcare access disparities and improve pain management for all individuals affected by cancer.

Healthcare professionals' knowledge, understanding and confidence to manage chronic pain after cancer treatment: A UK survey

INTRODUCTION

Healthcare professionals are vital in preparing people living with and beyond cancer about the risks of chronic pain after cancer treatment. To do so, healthcare professionals need to be knowledgeable and confident about chronic pain after cancer treatment, yet little is known about their understanding or confidence of this common long-term and late side effect of cancer treatment.

AIM

To identify healthcare professionals' knowledge and understanding of chronic pain after cancer treatment and consider how confident they are to inform, listen and signpost people living with and beyond cancer to appropriate information and support.

METHOD

A cross sectional online survey was distributed to healthcare professionals in the UK via cancer and primary care networks, cancer alliances and social media. The survey consisted of four domains: 1) knowledge and understanding, 2) information and support, 3) confidence and 4) barriers. Quantitative data were analysed with descriptive statistics and free text comments were analysed using qualitative content analysis.

RESULTS

Healthcare professionals reported limited knowledge and understanding of chronic pain after cancer treatment. Healthcare professionals lacked confidence to talk to people about chronic pain after cancer treatment and viewed their lack of knowledge as a barrier. Additional barriers included 'Limited service provision', 'Conflict between services', 'Not my role' and 'Challenges in diagnosing chronic pain in cancer survivors'.

CONCLUSION

Chronic pain after cancer can be a significant issue for those living with and beyond cancer, yet healthcare professionals report limited knowledge of it or understanding of the impact. More education is needed to increase healthcare professionals' knowledge and confidence in chronic pain after cancer treatment.

Targeting TRPV4 Channels for Cancer Pain Relief

Despite the unique and complex nature of cancer pain, the activation of different ion channels can be related to the initiation and maintenance of pain. The transient receptor potential vanilloid 4 (TRPV4) is a cation channel broadly expressed in sensory afferent neurons. This channel is activated by multiple stimuli to mediate pain perception associated with inflammatory and neuropathic pain. Here, we focused on summarizing the role of TRPV4 in cancer etiology and cancer-induced pain mechanisms. Many studies revealed that the administration of a TRPV4 antagonist and TRPV4 knockdown diminishes nociception in chemotherapy-induced peripheral neuropathy (CIPN). Although the evidence on TRPV4 channels' involvement in cancer pain is scarce, the expression of these receptors was reportedly enhanced in cancer-induced bone pain (CIBP), perineural, and orofacial cancer models following the inoculation of tumor cells to the bone marrow cavity, sciatic nerve, and tongue, respectively. Effective pain management is a continuous problem for patients diagnosed with cancer, and current guidelines fail to address a mechanism-based treatment. Therefore, examining new molecules with potential antinociceptive properties targeting TRPV4 modulation would be interesting. Identifying such agents could lead to the development of treatment strategies with improved pain-relieving effects and fewer adverse effects than the currently available analgesics.

Pain in Long-Term Cancer Survivors: Prevalence and Impact in a Cohort Composed Mostly of Breast Cancer Survivors

Cancer survival is becoming more common which means that there is now a growing population of cancer survivors, in whom pain may be common. However, its prevalence has hardly been addressed systematically. We aimed to assess the prevalence and explore the pathophysiology and impact of pain on health outcomes in cancer survivors. We conducted a retrospective-prospective cohort study in cancer-free patients diagnosed with cancer at least five years before the study start date. We used multivariable regression to establish the association of patients' cancer characteristics with pain, and then the association of patients' pain features with health outcomes and related symptoms. Between March and July 2021, 278 long-term cancer survivors were evaluated. Almost half of them (130/278, 46.8%) had pain, of whom 58.9% had a probable neuropathic component, but only 18 (13.8%) were taking specific drugs for neuropathic pain. A history of surgery-related pain syndrome in breast cancer patients was more than twice as frequent in the pain cohort. Post-chemotherapy and post-radiotherapy pain syndromes were uncommon. Pain was associated with lower QoL, emotional functioning, professional performance, and disability scores. Pain is a frequent health determinant in cancer survivors. Referral to specialised pain services may be a reasonable move in some cases.

Scheduled and Breakthrough Opioid Use for Cancer Pain in an Inpatient Setting at a Tertiary Cancer Hospital

Background: Our aim was to examine the frequency and prescription pattern of breakthrough (BTO) and scheduled (SCH) opioids and their ratio (BTO/SCH ratio) of use, prior to and after referral to an inpatient supportive care consult (SCC) for cancer pain management (CPM). Methods and Materials: Patients admitted at the MD Anderson Cancer Center and referred to a SCC were retrospectively reviewed. Cancer patients receiving SCH and BTO opioids for ≥24 h were eligible for inclusion. Patient demographics and clinical characteristics, including the type and route of SCH and BTO opioids, daily opioid doses (MEDDs) of SCH and BTO, and BTO/SCH ratios were reviewed in patients seen prior to a SCC (pre-SCC) and during a SCC. A normal BTO ratio was defined as 0.5-0.2. Results: A total of 665/728 (91%) patients were evaluable. Median pain scores (p < 0.001), BTO MEDDs (p < 0.001), scheduled opioid MEDDs (p < 0.0001), and total MEDDs (p < 0.0001) were higher, but the median number of BTO doses was fewer (2 vs. 4, p < 0.001), among patients seen at SCC compared to pre-SCC. A BTO/SCH ratio over the recommended ratio (>0.2) was seen in 37.5% of patients. The BTO/SCH ratios in the pre-SCC and SCC groups were 0.10 (0.04, 0.21) and 0.17 (0.10, 0.30), respectively, p < 0.001. Hydromorphone and Morphine were the most common BTO and SCH opioids prescribed, respectively. Patients in the early supportive care group had higher pain scores and MEDDs. Conclusions: BTO/SCH ratios are frequently prescribed higher than the recommended dose. Daily pain scores, BTO MEDDs, scheduled opioid MEDDs, and total MEDDs were higher among the SCC group than the pre-SCC group, but the number of BTO doses/day was lower.

Pain after cancer: Time to move towards a mechanism-based approach!

The high prevalence and the debilitating nature of pain following cancer urge the need for appropriate pain assessment and management in this population. Yet cancer pain remains under-recognized and under-treated. For effective pain management, correct identification of the presence of different underlying pain mechanisms is warranted, since pain management strategies differ considerably according to the predominant mechanisms. To raise awareness around possible underlying pain mechanisms in pain after cancer, the three major pain mechanisms are shortly explained and translated to this specific population. Next, in this Special Issue, we delve further into the existing evidence on the presence of these pain mechanisms in patients with pain after cancer, and on how they can be assessed or approached in patients with pain after cancer.

A Narrative Review of the Current Research in Cancer-Related Pain Inequities: The Necessity of Applying Intersectionality to Advance Cancer Pain Research

Cancer-related pain has a significant impact on quality of life for patients with cancer. In populations without cancer, there are documented pain inequities associated with minoritized racial and/or ethnic groups, women, and low socioeconomic status. However, our understanding of pain inequities specifically among patients with cancer remains incomplete. We narratively synthesized published quantitative research on cancer-related pain inequities in the US in the past decade. A search identified 17 English-language articles examining pain for patients with various cancer types at different treatment stages. Our review revealed mixed findings comparing cancer-related pain by racial group (e.g., Black vs White) and sex (male vs female), but consistent findings indicating that people with lower (vs higher) socioeconomic status and younger (vs older) patients report more cancer-related pain. Research on cancer pain among sexual and gender minorities remains scant. Key research gaps include a need for more research that incorporates an intersectional perspective by exploring intersecting subgroups and measuring social and structural processes that drive pain inequities. These findings underscore an important need for researchers to use an intersectional approach to cancer pain to help elucidate key populations at-risk for exacerbated cancer-related pain and identify ways to mitigate social and structural processes that drive these inequities.

Cancer-related pain experienced in daily life is difficult to communicate and to manage - for patients and for professionals

OBJECTIVES

The aim of this study was to gain qualitative insight into cancer patients' experiences, explanations, and management strategies regarding their cancer-related pain (CP).

METHODS

Seventeen patients with CP were interviewed using a semi-structured interview approach. Braun and Clarke's thematic analysis method was used to analyze the transcribed interviews. The patients all participated in cancer rehabilitation courses arranged by the research clinic at The Danish Knowledge Centre for Rehabilitation and Palliative Care.

RESULTS

Three themes were identified: (1) Explaining CP: Patients found it difficult to explain how they experienced their pain. They lacked words, and they frequently used invasive metaphors such as "Pain feels like a heart attack" (2). Strategies and barriers to the management of CP: Initiatives provided by healthcare professionals (HCPs) were perceived as insufficient, and the patients missed guidance in both pharmacological and non-pharmacological approaches to pain management. Several saw medicine as unnatural for their body, and they focused on side effects and the medicine affecting their quality of life. (3) Responsibility for managing CP: A lack of responsiveness from the HCPs and taking on responsibility for pain management were experienced by several of the patients. The patients expressed uncertainty about whom to contact for help with the management of their CP.

CONCLUSION

The patients' difficulties in explaining, understanding, and communicating their pain and pain management contributed to insufficient pain management. They were also uncertain about who had the responsibility to help them to achieve pain relief. These results share the evidence drawn from studies on patients with chronic non-cancer pain. This qualitative study highlights the need for having more focus on a common language and shared understanding between patients and HCPs. It also underpins the importance of HCPs to assume their responsibility to help patients manage their pain conditions.

Phase III study of bilayer sustained-release tramadol tablets in patients with cancer pain: a double-blind parallel-group, non-inferiority study with immediate-release tramadol capsules as an active comparator

PURPOSE

We investigated whether twice-daily administration of a bilayer tablet formulation of tramadol (35% immediate-release [IR] and 65% sustained-release) is as effective as four-times-daily IR tramadol capsules for managing cancer pain.

METHODS

This randomized, double-blind, double-dummy, active-comparator, non-inferiority study enrolled opioid-naïve patients using non-steroidal anti-inflammatory drugs or acetaminophen (paracetamol) to manage cancer pain and self-reported pain (mean value over 3 days ≥ 25 mm on a 100-mm visual analog scale [VAS]). Patients were randomized to either bilayer tablets or IR capsules for 14 days. The starting dose was 100 mg/day and could be escalated to 300 mg/day. The primary endpoint was the change in VAS (averaged over 3 days) for pain at rest from baseline to end of treatment/discontinuation.

RESULTS

Overall, 251 patients were randomized. The baseline mean VAS at rest was 47.67 mm (range: 25.6-82.7 mm). In the full analysis set, the adjusted mean change in VAS was - 22.07 and - 19.08 mm in the bilayer tablet (n = 124) and IR capsule (n = 120) groups, respectively. The adjusted mean difference was - 2.99 mm (95% confidence interval [CI] - 7.96 to 1.99 mm). The upper 95% CI was less than the predefined non-inferiority margin of 7.5 mm. Other efficacy outcomes were similar in both groups. Adverse events were reported for 97/126 (77.0%) and 101/125 (80.8%) patients in the bilayer tablet and IR capsule groups, respectively.

CONCLUSION

Twice-daily administration of bilayer tramadol tablets was as effective as four-times-daily administration of IR capsules regarding the improvement in pain VAS, with comparable safety outcomes.

CLINICAL TRIAL REGISTRATION

JapicCTI-184143/jRCT2080224082 (October 5, 2018).

Barriers and facilitators to physical activity in cancer survivors with pain: a systematic review

PURPOSE

Pain post-treatment is a debilitating symptom in the growing population of cancer survivors. While physical activity is an integral part of pain management, low levels of physical activity are often observed in this population. The aim of this systematic review is to gain insight into the barriers and facilitators to physical activity in cancer survivors afflicted with pain.

METHODS

In December 2021, a systematic search was conducted using PubMed and Web of Science. All studies exploring barriers and/or facilitators to physical activity in cancer survivors with pain were included. The methodological quality of the evidence was appraised with the Mixed Methods Appraisal Tool (version 2018).

RESULTS

Six articles were included. Current literature was limited and mostly focused on female breast cancer survivors. The identified barriers and facilitators could be categorized into six different domains: the logistical, symptoms, cognitive, clinical, social, and knowledge domain. The barrier of pain was reported as a barrier on its own that is closely linked to other barriers in this specific population.

CONCLUSION

Barriers and facilitators to physical activity were categorized in six different domains. The barrier of pain distinguishes itself and brings along additional obstacles such as anxiety, fear, and avoidance behavior. Current evidence is limited and focuses mostly on female breast cancer survivors. Further research in larger cohorts representing various subsets of cancer survivors with pain is warranted, as well as studies that implement these insights in physical activity interventions.

Health Outcomes with Curative and Palliative Therapies in Real World: Role of the Quality of Life Summary Score in Thoracic Oncology Patients

BACKGROUND

For patients receiving therapy with curative or palliative intent for a thoracic malignancy, prediction of quality of life (QOL), once therapy starts, remains challenging. The role of health assessments by the patient instead of the doctor herein remains ill-defined.

AIMS

To assess the evolution of QOL in patients with thoracic malignancies treated with curative and palliative intent, respectively. To identify factors that determine QOL one year after the start of cancer therapy. To identify factors that affect survival.

METHODS

We prospectively included consecutive patients with a thoracic malignancy who were starting anti-cancer therapy and measured QOL with QLQ-C30 before the start of therapy, and thereafter at regular intervals for up to 12 months. A multivariate regression analysis of the global health score (GHS) and QOL summary scores (QSS) one year after the start of therapy was conducted. A proportional hazards Cox regression was conducted to investigate the effects of case-mix variables on survival.

RESULTS

Of 587 new patients, 375 started different forms of therapy. Most had non-small cell lung cancer (n = 298), 35 had small cell lung cancer, and 42 had other thoracic malignancies or were diagnosed on imaging alone. There were 203 who went for a curative intent and 172 for a palliative intent strategy. The WHO score of 0-1 was more prevalent in the former group (p = 0.02), and comorbidities were equally distributed. At baseline, all QOL indices were better in the curative group (p < 0.05). The curative group was characterized by a significant worsening of GHS and QSS (p < 0.05). The palliative group was characterized by an improvement in GHS and emotional health (p < 0.05), while other dimensions of functioning remained stable. GHS at 12 months was estimated in a multivariate linear regression model (R2 = 0.23-p < 0.001) based on baseline GHS, QSS, and comorbidity burden. QSS at 12 months was estimated (R2 = 0.31-p < 0.001) by baseline QSS and therapeutic intent strategy (curative vs. palliative). The prognostic factors for overall survival were the type of therapy (curative vs. palliative intent, p < 0.001) and occurrence of early toxicity-related hospitalization (grade ≥ 3, p = 0.001).

CONCLUSION

Patients with thoracic malignancies treated with curative intent experience a worsening of their QOL in the first year, whereas those receiving palliative anti-cancer therapy do not. QOL one year after the start of therapy depends on the baseline health scores as determined by the patient, comorbidity burden, and therapeutic strategy. Survival depends on therapeutic strategy and early hospitalization due to toxicity.

Central Sensitization in Cancer Survivors and Its Clinical Implications: State of the Art

Although the prevalence of cancer pain is 47% after treatment, cancer pain is often underestimated, and many patients are undertreated. The complexity of cancer pain contributes to the lack of its management. Recently, as the mechanism of cancer pain, it has become clear that central sensitization (CS) influences chronic pain conditions and the transition from acute to chronic pain. In this state-of-the-art review, we summarized the association of CS or central sensitivity syndrome with pain and the treatment for pain targeting CS in cancer survivors. The management of patients with CS should not only focus on tissue damage in either the affected body regions or within the central nervous system; rather, it should aim to target the underlying factors that sustain the CS process. Pain neuroscience education (PNE) is gaining popularity for managing chronic musculoskeletal pain and could be effective for pain and CS in breast cancer survivors. However, there is a study that did not demonstrate significant improvements after PNE, so further research is needed. Precision medicine involves the classification of patients into subgroups based on a multifaceted evaluation of disease and the implementation of treatment tailored to the characteristics of each patient, which may play a central role in the treatment of CS.

Efficacy of Essential Oils in Relieving Cancer Pain: A Systematic Review and Meta-Analysis

Over 80% of patients affected by cancer develops cancer-related pain, one of the most feared consequences because of its intractable nature, particularly in the terminal stage of the disease. Recent evidence-based recommendations on integrative medicine for the management of cancer pain underline the role of natural products. The present systematic review and meta-analysis aims at appraising for the first time the efficacy of aromatherapy in cancer pain in clinical studies with different design according to the most updated Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 recommendations. The search retrieves 1002 total records. Twelve studies are included and six are eligible for meta-analysis. The present study demonstrates significant efficacy of the use of essential oils in the reduction of the intensity of pain associated with cancer (p < 0.00001), highlighting the need for earlier, more homogeneous, and appropriately designed clinical trials. Good certainty body of evidence is needed for effective and safe management of cancer-related pain using essential oils by establishment of a step-by-step preclinical-to-clinical pathway to provide a rational basis for clinical use in integrative oncology. PROSPERO registration: CRD42023393182.