Radiotherapy-Specific Chronic Pain Syndromes in the Cancer Population: An Evidence-Based Narrative Review

Prevalence and characterization of pain in radiation oncology: the PREDORT multicenter cross-sectional study

BACKGROUND

Pain in cancer patients has enormous impact on their quality-of-life. Radiation therapy (RT) is a cornerstone in cancer treatment. The objective of the PREDORT study is to estimate the prevalence of pain in patients attending at Radiation Oncology (RO) Services.

METHODS

A prospective, multicenter study was designed for patients treated at the RO Services of reference hospitals. Patients were seen in their initial Nursing consultation, during which key data was collected, including demographic and comorbidities data, medical history, and oncological and pain characteristics. The study has received approval from the Ethics Committee of Navarra, and all patients signed the Informed Consent.

RESULTS

Of the 860 participating patients, 306 reported some type of pain, which implies a prevalence of 35.6%. Of them, 213 identified a cause of oncological origin. The proportion of pain was similar among sexes, but the proportion of non-cancer pain was higher among women (p < 0.05). Regarding pain intensity, the magnitude of breakthrough pain in patients with oncological pain is nearly 1 point greater than in patients with non-oncological pain (7.53 vs 6.81; p = 0.064). Cancer pain is more likely to be limiting of normal life than non-cancer pain (59% versus 38%, p < 0.001). Regarding analgesic treatment, only 60/306 patients (19.6%) were receiving strong opioids. There were 68 patients with pain without any treatment (22.2%).

CONCLUSIONS

The prevalence of pain in cancer patients referred to RO services is 35.6%, with the prevalence of exclusively oncological pain being 24.8%. Understanding and addressing oncological pain is essential to provide comprehensive care to patients.

Defining Spine Cancer Pain Syndromes: A Systematic Review and Proposed Terminology

STUDY DESIGN

Systematic Review.

OBJECTIVES

Formalized terminology for pain experienced by spine cancer patients is lacking. The common descriptors of spine cancer pain as mechanical or non-mechanical is not exhaustive. Misdiagnosed spinal pain may lead to ineffective treatment recommendations for cancer patients.

METHODS

We conducted a systematic review of pain terminology that may be relevant to spinal oncology patients. We provide a comprehensive and unbiased summary of the existing evidence, not limited to the spine surgery literature, and subsequently consolidate these data into a practical, clinically relevant nomenclature for spine oncologists.

RESULTS

Our literature search identified 3515 unique citations. Through title and abstract screening, 3407 citations were excluded, resulting in 54 full-text citations for review. Pain in cancer patients is typically described as nociceptive pain (somatic vs visceral), neurologic pain and treatment related pain.

CONCLUSIONS

We consolidate the terminology used in the literature and consolidated into clinically relevant nomenclature of biologic tumor pain, mechanical pain, radicular pain, neuropathic pain, and treatment related pain. This review helps standardize terminology for cancer-related pain which may help clinicians identify pain generators.

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.

Chronic Pain Following Breast Reconstruction: A Scoping Review

BACKGROUND

Breast cancer survival rates have increased significantly, underscoring the importance of enhancing long-term health-related quality of life. Breast reconstruction following mastectomy has emerged as a common approach that contributes to improved health-related quality of life. Nonetheless, chronic pain following breast reconstruction is a prevalent issue that has a negative impact on overall well-being.

METHODS

To examine recent findings on chronic pain after breast reconstruction and progress in pain management, we performed a review of the literature through independent searches using the MEDLINE database within NIH National Library of Medicine PubMed.

RESULTS

The review suggested that autologous reconstruction causes chronic postsurgical pain, especially at specific donor sites, whereas implant-based reconstruction does not seem to increase the risk of chronic pain. Moreover, certain operational and patient factors are also associated with chronic pain. Appropriate pain management can reduce chronic pain and prevent the transition from acute to chronic pain.

CONCLUSION

This scoping review evaluated the characteristics of long-term chronic pain after breast reconstruction. The findings provide patients with important treatment information and will assist with their decision on their preferred treatment.

The Impact of Pain on Mobility in Patients with Cancer

OBJECTIVES

Provide an overview of how pain impacts mobility in patients with cancer.

METHODS

A literature search was conducted in PubMed and on Google Scholar using search terms, cancer pain with mobility, acute and chronic pain syndromes, enhanced recovery after surgery, nursing care, and rehabilitation. Peer-reviewed research studies, review articles, and pain guidelines and position papers were reviewed to provide an overview on cancer pain, its impact on mobility, and the nurse's role in managing pain and optimizing mobility and functional outcomes.

RESULTS

Firty-two references were included in this overview. This body of literature is replete with studies on the management of pain; however, the tie between pain and mobility has not been well described aside from the breakthrough pain literature. This manuscript weaves these two important concepts together to better inform nurses and other clinicians regarding the importance of managing pain to even begin mobilizing patients, especially following surgery and for other painful conditions.

CONCLUSIONS

Oncology nurses play an integral role in assessing and managing cancer pain. It is important for nurses to recognize how their pain management interventions lead to improved mobility and functioning in patients with cancer.

IMPLICATIONS FOR NURSING PRACTICE

Nurses comprise the largest workforce around the globe and are well-equipped to assess and manage cancer pain in all cancer care settings. As leaders within the healthcare team, making recommendations to better control pain and communicating with other team members regarding the pain plan is essential in improving mobility in patients with cancer.

Comparative Analysis of Stereotactic Radiation Therapy and Conventional Radiation Therapy in Cancer Pain Control: A Systematic Review and Meta-Analysis

AIMS

Approximately 55% of patients diagnosed with primary or metastatic cancer endure pain directly attributable to the disease. Consequently, it becomes imperative to address pain management through a comparative analysis of stereotactic radiotherapy (SRT) and conventional radiation therapy (CRT), especially in light of the less efficacious improvement achieved solely through pharmacological interventions.

MATERIALS AND METHODS

A systematic exploration was undertaken on PubMed, the Cochrane Library, and Elsevier's ScienceDirect databases to identify studies that compare Stereotactic Radiotherapy to Conventional radiation therapy for pain management in individuals with metastatic bone cancer. The analyses were executed utilizing the random-effects model.

RESULTS

A cohort of 1152 participants with metastatic bone cancer was analyzed, demonstrating significantly higher complete pain relief in the Stereotactic Radiotherapy group during both early and late follow-up (RR: 1.61; 95% CI: 1.17, 2.23, p-value: 0.004; I2: 0%). Stereotactic Radiotherapy also showed a non-significant increase in the incidence of partial pain relief (RR: 1.07; 95% CI: 0.85, 1.34, p-value: 0.56; I2: 18%). Furthermore, Stereotactic Radiotherapy was associated with a significantly reduced risk of stationary pain throughout follow-up (RR: 0.61; 95%CI: 0.48, 0.76, p-value: <0.0001; I2: 0. The incidence of progressive pain was non-significantly reduced with Stereotactic Radiotherapy during both early and late follow-up (RR: 0.77; 95% CI: 0.50, 1.17, p-value: 0.22; I2: 0%). Secondary outcomes exhibited a non-significant trend favoring Stereotactic Radiotherapy for dysphagia, esophagitis, pain, and radiodermatitis, while a non-significant increase was observed for nausea, fatigue, and vertebral compression fracture.

CONCLUSION

In summary, stereotactic radiation therapy (SRT) has improved in achieving complete pain relief while exhibiting a decreased probability of delivering stationary pain compared to conventional radiation therapy (CRT). Nevertheless, it is crucial in future research to address a noteworthy limitation, specifically, the risk of vertebral compression fracture.

Evaluation and Management of Shoulder Dysfunction in Cancer Survivors

Purpose of Review

Shoulder dysfunction widely affects function and quality of life of cancer survivors. This paper discusses the etiology, identification, evaluation, and management of the common shoulder impairments seen in cancer survivors, particularly those with breast cancer, head and neck cancer, and Hodgkin lymphoma.

Recent Findings

Shoulder dysfunction can be caused by a wide range of sources, often as a sequelae of cancer treatments including surgery, systemic therapy, and radiation therapy. These can change the shoulder biomechanics leading to musculoskeletal disorders such as rotator cuff disease and adhesive capsulitis. Other etiologies include neuromuscular complications, such as post-breast surgery pain syndrome and radiation fibrosis syndrome, and lymphovascular disorders such as lymphedema and axillary web syndrome. Metastatic bone disease and primary bone cancer should be considered for those with intense shoulder pain. Detailed history and physical exam, and in some cases, imaging can assist with evaluation of shoulder issues. Exercise, physical and occupation therapy are essential in managing shoulder dysfunction.

Summary

Shoulder dysfunction can limit function and quality of life for cancer survivors. It is important to consider the possible etiologies as accurate diagnosis is critical for optimal treatment.

Pain management in cervical cancer

Cervical cancer (CC) occupies the second place in incidence and mortality among women in México. Despite this, Cervical Cancer continues to have a late diagnosis which leads to a high rate of complications. Pain represents the most feared and disabling symptom, being present in up to 86% of patients with advanced disease. The approach to managing pain in this population has not been studied and described to a full extent. In addition, there is a pressing need to provide concise recommendations to promote adequate pain control. We performed a review of the literature in CC and had experts in the field of pain management evaluate the evidence found. We then issued relevant recommendations on pharmacology and interventional pain management. Thus, the approach to pain management must be comprehensive and individualized, considering the timely and appropriate use of pharmacologic treatment as well as interventional procedures.

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.

Systematic Review of Genetic Polymorphisms Associated with Acute Pain Induced by Radiotherapy for Head and Neck Cancers

Background/objective

Pain is the most common acute symptom following radiation therapy (RT) for head and neck cancer (HNC). The multifactorial origin of RT-induced pain makes it highly challenging to manage. Multiple studies were conducted to identify genetic variants associated with cancer pain, however few of them focused on RT-induced acute pain. In this review, we summarize the potential mechanisms of acute pain after RT in HNC and identify genetic variants associated with RT-induced acute pain and relevant acute toxicities.

Methods

A comprehensive search of Ovid Medline, EMBASE and Web of Science databases using terms including "Variants", "Polymorphisms", "Radiotherapy", "Acute pain", "Acute toxicity" published up to February 28, 2022, was performed by two reviewers. Review articles and citations were reviewed manually. The identified SNPs associated with RT-induced acute pain and toxicities were reported, and the molecular functions of the associated genes were described based on genetic annotation using The Human Gene Database; GeneCards.

Results

A total of 386 articles were identified electronically and 8 more articles were included after manual search. 21 articles were finally included. 32 variants in 27 genes, of which 25% in inflammatory/immune response, 20% had function in DNA damage response and repair, 20% in cell death or cell cycle, were associated with RT-inflammatory pain and acute oral mucositis or dermatitis. 4 variants in 4 genes were associated with neuropathy and neuropathic pain. 5 variants in 4 genes were associated with RT-induced mixed types of post-RT-throat/neck pain.

Conclusion

Different types of pain develop after RT in HNC, including inflammatory pain; neuropathic pain; nociceptive pain; and mixed oral pain. Genetic variants involved in DNA damage response and repair, cell death, inflammation and neuropathic pathways may affect pain presentation post-RT. These variants could be used for personalized pain management in HNC patients receiving RT.

'I think it affects every aspect of my life, really': Cancer survivors' experience of living with chronic pain after curative cancer treatment in England, UK

AIM

To explore cancer survivors' experiences of living with chronic pain after curative cancer treatment in England, UK.

METHODS

A qualitative study using telephone interviews with adult cancer survivors experiencing chronic pain after curative cancer treatment. Interview data was analysed using a reflexive thematic approach [1-3].

FINDINGS

Nineteen participants: 14 female, 5 male, mean age 62.4 years, 1.5-48 years since cancer diagnosis, eight tumour groups represented. Six participants (31.6%) developed chronic pain more than ten years after completing cancer treatment (range 0-25 years). Five themes were generated which highlighted the experience of chronic pain after cancer treatment for cancer survivors: 1) 'Hear me… believe me…. Please'. Survivors felt that they had not been listened to when they tried to talk about their chronic pain after cancer treatment, nor at times, believed. 2) 'Expectation versus reality'. Survivors had anticipated returning to pre cancer quality of life yet living in chronic pain prevented them from doing so. 3) 'They don't understand…. We don't understand'. Cancer survivors did not feel informed or prepared for the risk or reality of chronic pain after cancer treatment and this compounded the difficulties of coping with and managing their pain. They felt health care professionals lacked knowledge and understanding of chronic pain after cancer. 4) 'Negotiating the maze'. Cancer survivors encountered unclear and limited pathways for support, often bouncing from one support team to another. Identifying and accessing services was a challenge, and the responsibility of this was often left to the survivor. 5) 'Validate my pain, validate me'. Palpable relief and benefit was felt when health care professionals diagnosed and acknowledged their chronic pain after cancer treatment.

CONCLUSIONS

Cancer survivors can feel ill prepared for the risk of chronic pain after cancer treatment and can experience challenges accessing support from healthcare professionals and clinical services.

Enhanced acupuncture therapy for radiotherapy-related neuropathic pain in patients with gynecologic cancer: a report of two cases and brief review

As radiation therapy is increasingly utilized in the treatment of cancer, neuropathic pain (NP) is a common radiotherapy-related adverse effect and has a significant impact on clinical outcomes negatively. However, despite an improved understanding of neuropathic pain management, pain is often undertreated in patients with cancer. Herein, we reported two cases with radiotherapy-related neuropathic pain (RRNP) who presented a positive reaction to acupuncture. Patient 1 (a 73-year-old woman) with gynecologic cancer complained of burning and electric shock-like pain in the lower limb after radiotherapy. With the accepted combination of acupuncture and drugs, the pain was alleviated completely in 8 weeks. Patient 2 (a 64-year-old woman) accepted acupuncture in the absence of medication because of her inability to tolerate the adverse events of anticonvulsant drugs. She achieved remission of pain 4 weeks later. The results of this study showed that acupuncture might be promising for controlling the RRNP in patients with cancer, especially who were intolerant or unresponsive to medications.

Incidence, risk factors, prevention and treatment of postmastectomy pain syndrome in breast cancer: A multicenter study

BACKGROUND

Postmastectomy pain syndrome (PMPS) is a common postoperative condition after breast cancer surgery.

PURPOSE

The aim of this study was to investigate the incidence rate and risk factors of PMPS, and to propose prevention and treatment methods.

METHODS

The study included 1790 postoperative breast cancer patients from three hospitals from 2017 to 2021, of which 302 (13.0%) patients with PMPS were included in the study.

RESULTS

Age, breast surgery type, axillary surgery type and radiotherapy are the risk factors of PMPS. Age, radiotherapy and chemotherapy affect the pain degree of PMPS during movement.

CONCLUSIONS

For breast cancer patients with high risk factors, pain should be actively prevented during perioperative period. Oral pharmacological agents, multidisciplinary combination therapy, local anesthetics and regional anesthesia are the most common treatment of PMPS.

Radioprotective and Radiomitigative Effects of Melatonin in Tissues with Different Proliferative Activity

We used various markers to analyze damage to mouse tissues (spleen and cerebral cortex) which have different proliferative activity and sensitivity to ionizing radiation (IR). We also assessed the degree of modulation of damages that occurs when melatonin is administered to mice prior to and after their X-ray irradiation. The data from this study showed that lesions in nuclear DNA (nDNA) were repaired more actively in the spleen than in the cerebral cortex of mice irradiated and treated with melatonin (N-acetyl-5-methoxytryptamine). Mitochondrial biogenesis involving mitochondrial DNA (mtDNA) synthesis was activated in both tissues of irradiated mice. A significant proportion of the newly synthesized mtDNA molecules were mutant copies that increase oxidative stress. Melatonin reduced the number of mutant mtDNA copies and the level of H2O2 in both tissues of the irradiated mice. Melatonin promoted the restoration of ATP levels in the tissues of irradiated mice. In the mouse tissues after exposure to X-ray, the level of malondialdehyde (MDA) increased and melatonin was able to reduce it. The MDA concentration was higher in the cerebral cortex tissue than that in the spleen tissue of the mouse. In mouse tissues following irradiation, the glutathione (GSH) level was low. The spleen GSH content was more than twice as low as that in the cerebral cortex. Melatonin helped restore the GSH levels in the mouse tissues. Although the spleen and cerebral cortex tissues of mice differ in the baseline values of the analyzed markers, the radioprotective and radiomitigative potential of melatonin was observed in both tissues.

Traditionally Used Natural Products in Preventing Ionizing Radiation-Induced Dermatitis: First Review on the Clinical Studies

In the treatment of cancer, the use of ionizing radiation is an important modality. However, on the downside, radiation, when used for curative purposes, causes acute dermatitis or radiodermatitis at the site of radiation in most individuals. From a clinical viewpoint, severe dermatitis causes a burning and itching sensation is very painful, and severely affects the quality of life of the individual undergoing treatment. In worse situations, acute radiation dermatitis can cause gaps or breaks in the planned treatment and this can adversely affect the treatment objective and outcome.

BACKGROUND

In various traditional and folk systems of medicine, plants and plant products have been used since time immemorial for treating various skin ailments. Further, many cosmeceutical creams formulated based on knowledge from ethnomedicinal use are marketed and used to treat various ailments. In the current review, an attempt is made at summarizing the beneficial effects of some plants and plant products in mitigating acute radiation dermatitis in humans undergoing curative radiotherapy. Additionally, the emphasis is also placed on the mechanism/s responsible for the beneficial effects.

OBJECTIVE

The objective of this review is to summarize the clinical observations on the prevention of radiodermatitis by plant products. In this review, the protective effects of Adlay (Coix lachryma-jobi L.) bran extract, Aloe vera, Calendula officinalis, Cucumis sativus, green tea constituent the epigallocatechin-3-gallate, honey, Achillea millefolium, Matricaria chamomilla, olive oil and some polyherbal creams are addressed by also addressing on the mechanism of action for the beneficial effects.

METHODS

Two authors' data mined for information in Google Scholar, PubMed, Embase and the Cochrane Library for publications in the field from 1901 up to July 2020. The focus was on acute radiation dermatitis, ionizing radiation, curative radiotherapy, human cancer. The articles were collected and analyzed.

RESULTS

For the first time, this review addresses the usefulness of natural products like adlay bran, Aloe vera, Calendula officinalis, Cucumis sativus, green tea constituent the epigallocatechin-3-gallate, honey, Achillea millefolium, Matricaria chamomilla, olive oil and some experimentally constituted and commercially available polyherbal creams as skincare agents against the deleterious effects of ionizing radiation on the skin. The protective effects are possibly due to the free radical scavenging, antioxidant, anti-inflammatory, wound healing and skin protective effects.

CONCLUSION

The authors suggest that these plants have been used since antiquity as medicinal agents and require in-depth investigation with both clinical and preclinical validated models of study. The results of these studies will be extremely useful to cancer patients requiring curative radiotherapy, the dermatology fraternity, agro-based and pharmaceutical sectors at large.