Neuropathic pain following breast cancer surgery: proposed classification and research update

Persistent Pain After Breast Cancer Treatment, an Underreported Burden for Breast Cancer Survivors

BACKGROUND

Many patients who have undergone surgery experience persistent pain after breast cancer treatment (PPBCT). These symptoms often remain unnoticed by treating physician(s), and the pathophysiology of PPBCT remains poorly understood. The purpose of this study was to determine prevalence of PPBCT and examine the association between PPBCT and various patient, tumor, and treatment characteristics.

PATIENTS AND METHODS

We conducted a questionnaire-based cross-sectional study enrolling patients with breast cancer treated at Máxima Medical Center between 2005 and 2016. PPBCT was defined as pain in the breast, anterior thorax, axilla, and/or medial upper arm that persists for at least 3 months after surgery. Tumor and treatment characteristics were derived from the Dutch Cancer Registry and electronic patient files.

RESULTS

Between February and March 2019, a questionnaire was sent to 2022 women, of whom 56.5% responded. Prevalence of PPBCT among the responders was 37.9%, with 50.8% reporting moderate to severe pain. Multivariable analyses showed that women with signs of anxiety, depression or a history of smoking had a higher risk of experiencing PPBCT. Women aged 70 years or older at diagnosis were significantly less likely to report PPBCT compared with younger women. No significant association was found between PPBCT and treatment characteristics, including type of axillary surgery and radiotherapy.

CONCLUSIONS

A considerable percentage of patients with breast cancer experience PPBCT. Women with signs of anxiety or depression and women with a history of smoking are more likely to report PPBCT. Further research is required to understand the underlying etiology and to improve prevention and treatment strategies for PPBCT.

Prevention of Post-Mastectomy Pain Syndrome: A Review of Recent Literature on Perioperative Interventions

PURPOSE OF REVIEW

Up to 60% of breast cancer patients continue to experience pain three months or more after surgery, with 15 to 25% reporting moderate to severe pain. Post-mastectomy pain syndrome (PMPS) places a high burden on patients. We reviewed recent studies on perioperative interventions to prevent PMPS incidence and severity.

RECENT FINDINGS

Recent studies on pharmacologic and regional anesthetic interventions were reviewed. Only nine of the twenty-three studies included reported a significant improvement in PMPS incidence and/or severity, sometimes with mixed results for similar interventions. Evidence for prevention of PMPS is mixed. Further investigation of impact of variations in dosing is warranted. In addition, promising newer interventions for prevention of PMPS such as cryoneurolysis of intercostal nerves and stellate ganglion block need confirmatory studies.

Pain mechanisms in the transgender individual: a review

Specific Aim

Provide an overview of the literature addressing major areas pertinent to pain in transgender persons and to identify areas of primary relevance for future research.

Methods

A team of scholars that have previously published on different areas of related research met periodically though zoom conferencing between April 2021 and February 2023 to discuss relevant literature with the goal of providing an overview on the incidence, phenotype, and mechanisms of pain in transgender patients. Review sections were written after gathering information from systematic literature searches of published or publicly available electronic literature to be compiled for publication as part of a topical series on gender and pain in the Frontiers in Pain Research.

Results

While transgender individuals represent a significant and increasingly visible component of the population, many researchers and clinicians are not well informed about the diversity in gender identity, physiology, hormonal status, and gender-affirming medical procedures utilized by transgender and other gender diverse patients. Transgender and cisgender people present with many of the same medical concerns, but research and treatment of these medical needs must reflect an appreciation of how differences in sex, gender, gender-affirming medical procedures, and minoritized status impact pain.

Conclusions

While significant advances have occurred in our appreciation of pain, the review indicates the need to support more targeted research on treatment and prevention of pain in transgender individuals. This is particularly relevant both for gender-affirming medical interventions and related medical care. Of particular importance is the need for large long-term follow-up studies to ascertain best practices for such procedures. A multi-disciplinary approach with personalized interventions is of particular importance to move forward.

Women's Experiences of Sequelae After Mastectomy: A 3, 6, and 12 Months' Follow-up Study

BACKGROUND

Postoperative experiences after breast cancer surgery, such as lymphedema, phantom breast sensations, persistent chronic pain, and changes in body image and sexuality, can negatively impact women's quality of life.

OBJECTIVE

To investigate women's experiences of sequelae at 3, 6, and 12 months after mastectomy.

METHODS

A survey including women ≥18 years, cognitively intact, and Danish speaking was conducted from May 2021 to October 2021. The researchers contacted the participants by telephone using 4 validated questionnaires investigating phantom sensation, body image, quality of life, and sexuality.

RESULTS

Forty-four women were eligible for participation, and 23 (14 women aged ≤65 years and 9 women aged >66 years) were included in the analysis. The results showed an overall decrease in the severity of physical sequelae and an improvement in body image and sexual function. However, the women reported concerns about the future and decreased sexual enjoyment. Nearly half of the women received information about sexuality from healthcare professionals.

CONCLUSION

The study demonstrated decreased sequelae during the follow-up period. Still, there seem to be unanswered questions concerning the quality of life and the content of information regarding sexuality. The findings require attention and further research to benefit the individual woman and her partner in accommodating the consequences after mastectomy.

IMPLICATIONS FOR PRACTICE

Persistent pain and concerns for the future are present for half of the women after 1 year. Information about possible changes in sexuality is not standard. A nurse-patient dialogue that discusses hospitalization and sexuality on an individual level can be a way to address concerns and challenges.

The influence of advanced age on long-term postsurgical analgesic use in patients receiving neuraxial anaesthesia for elective surgery

OBJECTIVE

To determine the relationship between age and long-term postsurgical analgesic use in patients who underwent elective surgery with neuraxial anaesthesia.

DESIGN

Retrospective observational study using data from the National Health Insurance Research Database of Taiwan from 2015 to 2019.

SETTING

National Health Insurance Research Database of Taiwan.

PATIENTS

A total of 12,810 patients (6405 younger and 6405 older) matched using propensity score matching.

INTERVENTIONS

Older (≥65 years).

MEASUREMENTS

The use of long-term (3 or 6 months) postoperative analgesics, including opioids, as a surrogate marker of chronic postsurgical pain (CPSP) was analysed using logistic regression.

MAIN RESULTS

After 3 months of surgery, older adults had higher use of all analgesics (odds ratio [OR] = 1.15; 95% CI = 1.03-1.28) and opioids (OR = 1.18; 95% CI = 1.09-1.28) compared to younger patients. Similar results were observed after 6 months of surgery (all analgesic use: OR = 1.11; 95% CI = 1.03-1.20; opioid use: OR = 1.33; 95% CI = 1.07-1.81).

CONCLUSION

The findings from this study suggest that older adults are more likely to experience CPSP and have increased use of long-term analgesics, including opioids, after undergoing elective surgery with neuraxial anaesthesia. The study highlights the need for improved pain management strategies for older adults after surgery.

SIGNIFICANCE

Older age is an independent risk factor for long-term analgesic use after surgery under neuraxial anaesthesiaanesthesia, indicating an increased risk for chronic postsurgical pain.

Pain Levels Following Cosmetic Breast Surgery and An Easy-To-Use Pain Treatment Algorithm for Plastic Surgeons

INTRODUCTION

The purpose of this study was to examine the degrees of pain experienced following various breast cosmetic surgery procedures and to evaluate the existing pain treatment methods.

MATERIALS AND METHODS

Patients who underwent subpectoral breast augmentation, mastopexy, or breast reduction between 2017 and 2022 were evaluated retrospectively. A total of 90 patients were randomly selected, with 30 patients in each group. The visual analog scale (VAS) was used to assess pain levels. The data were analyzed using the statistical program SPSS 22.0 (IBM Corp., Armonk, NY, USA).

RESULTS

The subpectoral breast augmentation group exhibited the highest recovery VAS score. Postoperative 1, 2, 4, 6, 12, and 24-h VAS values were higher in the breast augmentation group than in the breast reduction and mastopexy groups. No statistically significant difference observed between mastopexy and breast reduction in terms of VAS scores during the evaluation periods. Statistically significant higher VAS scores were observed for subpectoral breast augmentation at all times compared to the preoperative period.

CONCLUSIONS

Subpectoral breast augmentation is associated with higher levels of postoperative pain compared to breast reduction and mastopexy. Effective postoperative pain prevention is crucial following aesthetic breast surgeries. It not only helps to reduce hospital stays but also aids in patient recovery, facilitates a quicker return to daily activities, and enhances patient satisfaction. To achieve this objective, it is advantageous to utilize a practical pain treatment algorithm that is readily applicable.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Optimizing the use of ketamine to reduce chronic postsurgical pain in women undergoing mastectomy for oncologic indication: study protocol for the KALPAS multicenter randomized controlled trial

BACKGROUND

Mastectomies are commonly performed and strongly associated with chronic postsurgical pain (CPSP), more specifically termed postmastectomy pain syndrome (PMPS), with 25-60% of patients reporting pain 3 months after surgery. PMPS interferes with function, recovery, and compliance with adjuvant therapy. Importantly, it is associated with chronic opioid use, as a recent study showed that 1 in 10 patients continue to use opioids at least 3 months after curative surgery. The majority of PMPS patients are women, and, over the past 10 years, women have outpaced men in the rate of growth in opioid dependence. Standard perioperative multimodal analgesia is only modestly effective in prevention of CPSP. Thus, interventions to reduce CPSP and PMPS are urgently needed. Ketamine is well known to improve pain and reduce opioid use in the acute postoperative period. Additionally, ketamine has been shown to control mood in studies of anxiety and depression. By targeting acute pain and improving mood in the perioperative period, ketamine may be able to prevent the development of CPSP.

METHODS

Ketamine analgesia for long-lasting pain relief after surgery (KALPAS) is a phase 3, multicenter, randomized, placebo-controlled, double-blind trial to study the effectiveness of ketamine in reducing PMPS. The study compares continuous perioperative ketamine infusion vs single-dose ketamine in the postanesthesia care unit vs placebo for reducing PMPS. Participants are followed for 1 year after surgery. The primary outcome is pain at the surgical site at 3 months after the index surgery as assessed with the Brief Pain Inventory-short form pain severity subscale.

DISCUSSION

This project is part of the NIH Helping to End Addiction Long-term (HEAL) Initiative, a nationwide effort to address the opioid public health crisis. This study can substantially impact perioperative pain management and can contribute significantly to combatting the opioid epidemic.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05037123. Registered on September 8, 2021.

Effects of Physical Exercise and Motor Activity on Depression and Anxiety in Post-Mastectomy Pain Syndrome

BACKGROUND

Chronic post-surgical pain is a condition persisting for not less than 3 months after surgical intervention. It is evaluated that 25-60% of women who underwent breast cancer excision suffer from post-mastectomy pain syndrome, and anxiety, depression, sleep disturbance, and catastrophizing. Physical activity can reduce the risk of chronic diseases and has a good impact on mood and cognitive function. The aim of this study was to estimate the influence of physical activity on the intensity of pain, depression, and anxiety in women who underwent mastectomy for breast cancer removal.

METHODS

A prospective observational unicentric cohort study was performed. Patients were females who underwent unilateral or bilateral mastectomy. The Numerical Rating Scale (NRS) was used to measure pain intensity, Beck's Depression Inventory (BDI) for depression, and Generalized Anxiety Disorders-7 (GAD-7) for anxiety evaluation. Physical activity was assessed by the International Physical Activity Questionnaire (IPAQ). Interleukin (IL)-17, IL-1β, cortisol, adrenocorticotropic hormone (ACTH), and brain-derived neurotrophic factor (BDNF) were also evaluated in the blood of patients. All evaluations were assessed 3 and 6 months after the surgery.

RESULTS

Adequate physical activity reduced the intensity of pain, depression, and anxiety symptoms in women affected by post-mastectomy pain syndrome. Moreover, adequately active women showed a reduction in biomarkers of inflammation, cortisol, ACTH, and an increase of BDNF.

CONCLUSIONS

Our results suggest that physical activity can improve the quality of life, reduce the intensity of pain and inflammatory markers, and be useful in the reduction of associated anxiety and depression.

Pain associated with breast cancer: etiologies and therapies

Pain associated with breast cancer is a prevalent problem that negatively affects quality of life. Breast cancer pain is not limited to the disease course itself but is also induced by current therapeutic strategies. This, combined with the increasing number of patients living with breast cancer, make pain management for breast cancer patients an increasingly important area of research. This narrative review presents a summary of pain associated with breast cancer, including pain related to the cancer disease process itself and pain associated with current therapeutic modalities including radiation, chemotherapy, immunotherapy, and surgery. Current pain management techniques, their limitations, and novel analgesic strategies are also discussed.

Importance of Breast Sensation After Mastectomy: Evidence from Three Sources

Background

Every year, more than 90,000 U.S. women undergo mastectomy. More than 40% have reconstruction. Following reconstruction, most women experience persistent partial or complete numbness of the reconstructed breasts, and many experience pain. Yet, breast reconstruction procedures focus largely on esthetic outcomes with mixed impact on sensory outcomes and little attention to pain. This study examines whether and how breast sensation is important to women.

Materials and Methods

Conventional content analysis of extant qualitative data from a clinical registry (29 women with prior breast surgery for cancer, 2008-2022), a volunteer community sample (qualitative interviews with 6 women with and 5 without breast cancer, 2019), and from a Twitter social media survey (N = 32, 2022).

Results

Functions of the breast identified by women with and without cancer include breastfeeding, sexual function, and femininity. Five interrelated themes on the importance of breast sensation emerged among women with breast cancer history: sexual function, experience of partnered sex or relationship with one's sexual partner, breast embodiment, effect of breast pain on sexual function, and importance to psychological wellbeing. Women, advocates, and clinicians described a lack of patient-physician communication in this domain that exacerbates the negative impact of breast sensation loss on health and wellbeing.

Conclusions

Breast sensation is important to women following mastectomy, yet a gap exists in patient-physician communication about the impact of mastectomy and reconstruction on breast sensory function. Lessons for physicians, scientists, and skeptics are conveyed about why the basic integrity of women's bodies matters for practice and science.

The mechanisms and management of persistent postsurgical pain

An estimated 10%-50% of patients undergoing a surgical intervention will develop persistent postsurgical pain (PPP) lasting more than 3 months despite adequate acute pain management and the availability of minimally invasive procedures. The link between early and late pain outcomes for surgical procedures remains unclear-some patients improve while others develop persistent pain. The elective nature of a surgical procedure offers a unique opportunity for prophylactic or early intervention to prevent the development of PPP and improve our understanding of its associated risk factors, such as pre-operative anxiety and the duration of severe acute postoperative pain. Current perioperative pain management strategies often include opioids, but long-term consumption can lead to tolerance, addiction, opioid-induced hyperalgesia, and death. Pre-clinical models provide the opportunity to dissect mechanisms underpinning the transition from acute to chronic, or persistent, postsurgical pain. This review highlights putative mechanisms of PPP, including sensitisation of peripheral sensory neurons, neuroplasticity in the central nervous system and nociceptive signalling along the neuro-immune axis.

Opioid prescriptions at the point of surgery, bone metastasis, or death among patients with breast cancer in Japanese acute care hospitals: a claims-based, retrospective, longitudinal study

PURPOSE

Breast cancer is the most common cancer among Japanese women and often yields a better prognosis than other cancers. However, few studies have been conducted on pain control using opioids in Japan. In this study, we aimed to examine actual opioid use among breast cancer patients.

METHODS

Breast cancer patients were defined as female patients with a first breast cancer diagnosis during the observational period in an acute care hospital database (April 2008 - February 2020). We examined the percentage of patients prescribed opioids, the opioid amount per patient, and the opioid dosage per day around surgery, bone metastasis diagnosis, or death.

RESULTS

Overall, 217,722 breast cancer patients were identified. The percentage of patients prescribed opioids and the average amount of opioids per patient were highest in the month of surgery, 78% and 27 morphine milligram equivalents (MMEs), respectively. The average opioid dosage increased with time after surgery from 19 to 28 MMEs. Around bone metastasis, the percentage of patients prescribed opioids and the average opioid amount per patient peaked one month after the diagnosis, 31% and 371 MMEs, respectively. The average opioid dosage gradually increased from 22 to 35 MMEs in succeeding days after a bone metastasis diagnosis. The percentage of patients prescribed opioids and the average opioid amount per patient increased as the month of death approached.

CONCLUSION

We investigated opioid prescription trends around clinical events in breast cancer patients on a large scale in Japan. These results may be useful to control cancer pain among breast cancer patients.

Factors Associated With Guideline-Concordant Pharmacological Treatment for Neuropathic Pain Among Breast Cancer Survivors

PURPOSE

To identify factors associated with receiving guideline-concordant treatment among breast cancer survivors with neuropathic pain.

MATERIALS AND METHODS

A retrospective case-control study was conducted using the SEER-Medicare linked database. We included female breast cancer survivors diagnosed with non-metastatic breast cancer (stages 0-III) between 2007 and 2015 who developed treatment-related neuropathic pain during their survivorship period. Guideline-concordant treatment was defined based on NCCN guidelines. Factors associated with receiving guideline-concordant treatment were assessed using multivariable logistic regression and backward selection was used to identify potential associated factors.

RESULTS

Around 16.7% of breast cancer survivors in the study developed a neuropathic pain condition. The mean time to develop neuropathic pain was 1.4 years after beginning adjuvant treatment. On average, patients who developed neuropathic pain and received guideline-concordant treatment did so at 2.4 months after their neuropathic pain diagnosis. We found that survivors that are black and of other races were less likely to receive guideline-concordant treatment for breast cancer treatment-related neuropathic pain. Whereas survivors with diabetes, mental health disorders, hemiplegia, prior continuous opioid use, benzodiazepine use, nonbenzodiazepine CNS depressant use, or antipsychotic medication use were less likely to receive guideline-concordant treatment.

CONCLUSION

This study suggests that minority races, prior medication use, and comorbid conditions are associated with guideline-concordant treatment among breast cancer survivors with neuropathic pain. These findings warrant attention towards minority races to prescribe them guideline-concordant treatment as well as caution when prescribing concurrent pain medications to survivors with comorbidities and prior medication use.

Evaluating the effect of upper-body morbidity on quality of life following primary breast cancer treatment: a systematic review and meta-analysis

PURPOSE

Improvements in breast cancer management continue to increase survival and life expectancy after treatment. Yet the adverse effects of treatment may persist long term, threatening physical, psychological, and social wellbeing, leading to impaired quality of life (QOL). Upper-body morbidity (UBM) such as pain, lymphoedema, restricted shoulder range of motion (ROM), and impaired function are widely reported after breast cancer treatment, but evidence demonstrating its impact on QOL is inconsistent. Therefore, the aim of the study was to conduct a systematic review and meta-analysis evaluating the effect of UBM on QOL following primary breast cancer treatment.

METHODS

The study was prospectively registered on PROSPERO (CRD42020203445). CINAHL, Embase, Emcare, PsycInfo, PubMed/Medline, and SPORTDiscus databases were searched for studies reporting QOL in individuals with and without UBM following primary breast cancer treatment. Primary analysis determined the standardised mean difference (SMD) in physical, psychological, and social wellbeing scores between UBM + /UBM - groups. Secondary analyses identified differences in QOL scores between groups, according to questionnaire.

RESULTS

Fifty-eight studies were included, with 39 conducive to meta-analysis. Types of UBM included pain, lymphoedema, restricted shoulder ROM, impaired upper-body function, and upper-body symptoms. UBM + groups reported poorer physical (SMD =  - 0.99; 95%CI =  - 1.26, - 0.71; p < 0.00001), psychological (SMD =  - 0.43; 95%CI =  - 0.60, - 0.27; p < 0.00001), and social wellbeing (SMD =  - 0.62; 95%CI =  - 0.83, - 0.40; p < 0.00001) than UBM - groups. Secondary analyses according to questionnaire showed that UBM + groups rated their QOL poorer or at equal to, UBM - groups across all domains.

CONCLUSIONS

Findings demonstrate the significant, negative impact of UBM on QOL, pervading physical, psychological, and social domains.

IMPLICATIONS FOR CANCER SURVIVORS

Efforts to assess and minimise the multidimensional impact of UBM are warranted to mitigate impaired QOL after breast cancer.

Breast sensorisexual function: a novel patient-reported outcome measure of sexual sensory functions of the breast

BACKGROUND

A validated measure assessing sexual sensory functions of the breast is needed to optimize sexual and other health outcomes after breast procedures.

AIM

To describe the development of a patient-reported outcome measure (PROM) to assess breast sensorisexual function (BSF).

METHODS

We applied the PROMIS standards (Patient Reported Outcomes Measurement Information System) for measure development and evaluation of validity. An initial conceptual model of BSF was developed with patients and experts. A literature review yielded a pool of 117 candidate items that underwent cognitive testing and iteration. Forty-eight items were administered to an ethnically diverse, national panel-based sample of sexually active women with breast cancer (n = 350) or without (n = 300). Psychometric analyses were performed.

OUTCOMES

The main outcome was BSF, a measure that assesses affective (satisfaction, pleasure, importance, pain, discomfort) and functional (touch, pressure, thermoreception, nipple erection) sensorisexual domains.

RESULTS

A bifactor model fit to 6 domains-excluding 2 domains with only 2 items each and 2 pain-related domains-revealed a single general factor representing BSF that may be adequately measured by the average of the items. This factor, with higher values denoting better function and with the standard deviation set to 1, was highest among women without breast cancer (mean, 0.24), intermediate among women with breast cancer but not bilateral mastectomy and reconstruction (-0.01), and lowest among those with bilateral mastectomy and reconstruction (-0.56). Between women with and without breast cancer, the BSF general factor accounted for 40%, 49%, and 100% of the difference in arousal, ability to orgasm, and sexual satisfaction, respectively. Items in each of 8 domains demonstrated unidimensionality (ie, they measured 1 underlying BSF trait) and high Cronbach's alphas for the entire sample (0.77-0.93) and the cancer group (0.71-0.95). Correlations with sexual function, health, and quality of life were positive for the BSF general factor and mostly negative for the pain domains.

CLINICAL IMPLICATIONS

The BSF PROM can be used to assess the impact of breast surgery or other procedures on the sexual sensory functions of the breast in women with and without breast cancer.

STRENGTHS AND LIMITATIONS

The BSF PROM was developed by using evidence-based standards, and it applies to sexually active women with and without breast cancer. Generalizability to sexually inactive women and other women warrants further study.

CONCLUSION

The BSF PROM is a measure of women's breast sensorisexual function with evidence of validity among women affected and unaffected by breast cancer.

Optimising psychological treatment for pain after breast cancer: a factorial design study protocol in Denmark

INTRODUCTION

One in five breast cancer (BC) survivors are affected by persistent pain years after completing primary treatment. While the efficacy of psychological interventions for BC-related pain has been documented in several meta-analyses, reported effect sizes are generally modest, pointing to a need for optimisation. Guided by the Multiphase Optimization Strategy, the present study aims to optimise psychological treatment for BC-related pain by identifying active treatment components in a full factorial design.

METHODS AND ANALYSIS

The study uses a 2×3 factorial design, randomising 192 women with BC-related pain (18-75 years) to eight experimental conditions. The eight conditions consist of three contemporary cognitive-behavioural therapy components, namely: (1) mindful attention, (2) decentring, and (3) values and committed action. Each component is delivered in two sessions, and each participant will receive either zero, two, four or six sessions. Participants receiving two or three treatment components will be randomised to receive them in varying order. Assessments will be conducted at baseline (T1), session by session, every day for 6 days following the first session in each treatment component, at post-intervention (T2) and at 12-week follow-up (T3). Primary outcomes are pain intensity (Numerical Rating Scale) and pain interference (Brief Pain Inventory interference subscale) from T1 to T2. Secondary outcomes are pain burden, pain quality, pain frequency, pain catastrophising, psychological distress, well-being and fear of cancer recurrence. Possible mediators include mindful attention, decentring, and pain acceptance and activity engagement. Possible moderators are treatment expectancy, treatment adherence, satisfaction with treatment and therapeutic alliance.

ETHICS AND DISSEMINATION

Ethical approval for the present study was received from the Central Denmark Region Committee on Health Research Ethics (no: 1-10-72-309-40). Findings will be made available to the study funders, care providers, patient organisations and other researchers at international conferences, and published in international, peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT05444101).

Resistance Training-Induced Acute Hypoalgesia in Women With Persistent Pain After Breast Cancer Treatment

ABSTRACT

Fogh Rasmussen, GH, Madeleine, P, Arroyo-Morales, M, Voigt, M, and Kristiansen, M. Resistance training-induced acute hypoalgesia in women with persistent pain after breast cancer treatment. J Strength Cond Res 37(3): e16-e24, 2023-The aim of this study was to determine whether a single bout of resistance training (RT) produces acute exercise-induced hypoalgesia (EIH) in breast cancer survivors (BCS) suffering from persistent pain ≥1.5 years after treatment. Twenty individuals with self-reported pain ≥3 on a 0-10 Numerical Rating Scale after treatment for breast cancer completed 3 experimental sessions, (a) familiarization; (b) 1 repetition maximum (1RM) normalization, and (c) training, consisting of 3 sets of 10 repetitions at 60% of 1 repetition maximum. Pressure pain thresholds (PPTs) were measured before and after training for the dorsal and ventral shoulder regions of the affected side. Movement-evoked pain (MEP) and rating of perceived exertion (RPE) were collected immediately after each set. A p -value less than 0.05 was considered statistically significant. The results demonstrated a significant increase in PPTs of the ventral shoulder region after a single bout of RT ( p ≤ 0.05), indicating a localized analgesic response for this area. By contrast, no change was detected in PPTs on the dorsal shoulder region. No significant differences were found in MEP between sessions despite a significant increase in load and RPE during 1RM assessment ( p ≤ 0.05), indicating that MEP was not affected by increase in absolute and relative intensity. In conclusion, a single bout of submaximal RT reduced PPTs for the ventral shoulder region of BCS with persistent pain after treatment and was well tolerated. Hence, RT may be a useful therapeutic tool for managing persistent pain after breast cancer treatment in clinical practice.

Pain sensitivity and shoulder function among breast cancer survivors compared to matched controls: a case-control study

OBJECTIVE

Persistent pain and loss of shoulder function are common adverse effects to breast cancer treatment, but the extent of these issues in comparison with healthy controls is unclear for survivors beyond 1.5 years after treatment. The purpose of this study was to benchmark differences in pressure pain thresholds (PPT), maximal isokinetic muscle strength (MIMS), and active range of motion (ROM) of females with persistent pain ≥1.5 years after breast cancer treatment (BCS) compared with pain-free matched controls (CON), and examine the presence of movement-evoked pain (MEP) during assessment of MIMS.

METHODS

The PPTs of 18 locations were assessed using a pressure algometer and a numeric rating scale was used to assess intensity of MEP. Active ROM and MIMS were measured using a universal goniometer and an isokinetic dynamometer, respectively.

RESULTS

A two-way analysis of variance revealed that PPTs across all locations, MIMS for horizontal shoulder extension/flexion and shoulder adduction, active ROM for shoulder flexion, horizontal shoulder extension, shoulder abduction, and external shoulder rotation were significantly lower for BCS compared with CON (P < 0.05). MEP was significantly higher for BCS and MEP intensity had a significant, negative correlation with PPTs (P < 0.01).

DISCUSSION/CONCLUSION

BCS with persistent pain ≥1.5 years after treatment demonstrates widespread reductions in PPTs and movement-specific reductions in MIMS and active ROM of the affected shoulder, along with MEP during physical performance assessment.

IMPLICATIONS FOR CANCER SURVIVORS

BCS with persistent pain ≥1.5 years after treatment shows signs of central sensitization and may benefit from individualized rehabilitation.

Analgesic effectiveness of preoperative ultrasound-guided erector spinae plane block versus paravertebral nerve block for breast surgery: A systematic review and meta-analysis of four randomized controlled trials

OBJECTIVE

Our meta-analysis aimed to compare the analgesic effectiveness of ultrasound-guided preoperative erector spinae plane block (ESPB) versus paravertebral nerve block (PVB) in breast surgery.

METHODS

PubMed, EMBASE, and the Cochrane Library were searched for randomized controlled trials (RCTs) between January 1, 1980 and April 31, 2021. The primary endpoints were perioperative pain score, analgesic consumption, and assessment of the block procedure. The secondary endpoints were intraoperative hemodynamic response, duration of surgery, postoperative antiemetic consumption, and adverse effects.

RESULTS

Four RCTs comprised a total of 310 patients were included in our meta-analysis. No significant differences in the perioperative pain score and analgesic consumption were observed between ESPB and PVB in the operating room, post-anesthesia care unit (PACU), and ward (at 1, 16, 12, and 24 h), and the morning of postoperative day 1 (POD1) (all p > 0.05). Similarly, no significant differences in the duration of block, time to first analgesic, hemodynamic response, duration of surgery, postoperative antiemetic consumption, and adverse effects were observed (all p > 0.05). However, our meta-analysis revealed that ultrasound-guided preoperative ESPB significantly reduced the duration of procedure time and frequency of guidance interventions, as well as increased the block success rate among residents (all p < 0.05).

CONCLUSIONS

Both ultrasound-guided preoperative ESPB and PVB showed comparable analgesic effects in patients undergoing breast surgery. However, with a significantly shorter procedure time and higher block success rate, our findings suggest that ESPB may be a simple alternative to PVB in breast surgery.

Deficits in ascending pain modulation pathways in breast cancer survivors with chronic neuropathic pain: A resting-state fMRI study

Purpose

Breast cancer (BC) is the highest frequent malignancy in women globally. Approximately 25-60% of BC patients with chronic neuropathic pain (CNP) result from advances in treating BC. Since the CNP mechanism is unclear, the various treatment methods for CNP are limited. We aimed to explore the brain alternations in BC patients with CNP and the relationship between depression and CNP utilizing resting-state functional magnetic resonance imaging (rs-fMRI).

Methods

To collect the data, the female BC survivors with CNP (n = 20) and healthy controls (n = 20) underwent rs-fMRI. We calculated and compared the functional connectivity (FC) between the two groups using the thalamus and periaqueductal gray (PAG) as seed regions.

Results

Patients with BC showed increased depression and FC between the thalamus and primary somatosensory cortices (SI). Moreover, the Hospital Anxiety and Depression Scale-Depression (HADS-D) and pain duration were linked positively to the strength of FC from the thalamus to the SI. Furthermore, the thalamus-SI FC mediated the impact of pain duration on HADS-D.

Conclusion

In BC patients with CNP, the ascending pain regulation mechanism is impaired and strongly associated with chronic pain and accompanying depression. This research increased our knowledge of the pathophysiology of CNP in patients with BC, which will aid in determining the optimal therapeutic strategy for those patients.

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.

Efficacy of PECS block in addition to multimodal analgesia for postoperative pain management in patients undergoing outpatient elective breast surgery: A retrospective study

Background

Pectoralis nerve blocks (PECS) have been shown in numerous studies to be a safe and effective method to treat postoperative pain and reduce postoperative opioid consumption after breast surgery. However, there are few publications evaluating the PECS block effectiveness in conjunction with multimodal analgesia (MMA) in outpatient breast surgery. This retrospective study aims to evaluate the efficacy of PECS's blocks on perioperative pain management and opioid consumption.

Methods

We conducted a retrospective study to assess the efficacy of preoperative PECS block in addition to preoperative MMA (oral acetaminophen and/or gabapentin) in reducing opioid consumption in adult female subjects undergoing outpatient elective breast surgery between 2015 and 2020. A total of 228 subjects were included in the study and divided in two groups: PECS block group (received PECS block + MMA) and control Group (received only MMA). The primary outcome was to compare postoperative opioid consumption between both groups. The secondary outcome was intergroup comparisons of the following: postoperative nausea and vomiting (PONV), incidence of rescue antiemetic medication, PACU non-opioid analgesic medication required, length of PACU stay and the incidence of 30-day postoperative complications between both groups.

Results

Two hundred and twenty-eight subjects (n = 228) were included in the study. A total of 174 subjects were allocated in the control group and 54 subjects were allocated in the PECS block group. Breast reduction and mastectomy/lumpectomy surgeries were the most commonly performed procedures (48% and 28%, respectively). The total amount of perioperative (intraoperative and PACU) MME was 27 [19, 38] in the control group and 28.5 [22, 38] in the PECS groups (p = 0.21). PACU opioid consumption was 14.3 [7, 24.5] MME for the control group and 17 [8, 23] MME (p = 0.732) for the PECS group. Lastly, the mean overall incidence of postsurgical complications at 30 days was 3% (N = 5), being wound infection, the only complication observed in the PECS groups (N = 2), and hematoma (N = 2) and wound dehiscence (N = 1) in the control group.

Conclusion

PECS block combined with MMA may not reduce intraoperative and/or PACU opioid consumption in patients undergoing outpatient elective breast surgery.

Mindfulness-Based Stress Reduction in Breast Cancer Survivors with Chronic Neuropathic Pain: A Randomized Controlled Trial

Objectives

The purpose of this study was to compare the effects of group-delivered mindfulness-based stress reduction as compared to a waitlist control group among breast cancer survivors living with CNP.

Methods

A randomized controlled trial design was applied, and outcomes collected included pain, emotional function, quality of life, and global impression of change.

Results

A total of 98 women were randomized and included in analyses. The sample included 49 women in the mindfulness-based stress reduction group, and 49 women in the waitlist control group. The intervention group participants (mean age 51.3 years, standard deviation = 11.4) and waitlist participants (mean age 55.1 years, standard deviation = 9.6) reported an average pain duration of approximately three years. No significant differences were found on the primary outcome of the proportions of women with reduced pain interference scores from the time of randomization to 3 months after the intervention was received. No significant changes were found among secondary outcomes.

Conclusion

Our randomized clinical trial did not find significant benefits of group-based mindfulness-based stress reduction for the management of CNP. The current study findings should be replicated and are important to consider given ongoing concerns that nonsignificant results of mindfulness-based stress reduction are often unpublished.

Increased gray matter following mindfulness-based stress reduction in breast cancer survivors with chronic neuropathic pain: preliminary evidence using voxel-based morphometry

PURPOSE

To investigate the impact of Mindfulness-Based Stress Reduction (MBSR) on gray matter volume (GMV) in female breast cancer survivors who suffer from chronic neuropathic pain (CNP).

METHODS

Voxel-based morphometry (VBM) was used to explore differences in GMV in 13 MBSR trainees and 10 waitlisted controls, with MRI scans and self-report measures completed pre- and post-8 weeks of training.

RESULTS

Compared to controls, the MBSR group had greater GMV in the angular gyrus and middle frontal gyrus post-training. The MBSR group's right parahippocampal gyrus GMV increased from pre- to post-training, whereas the control group's left parahippocampal gyrus, precuneus, middle temporal gyrus, and right cuneus GMV decreased over the same time period. Pain interference was significantly reduced and mindfulness was significantly increased following MBSR for the intervention group only.

CONCLUSIONS

MBSR was associated with increased GMV in regions where GMV is known to (1) increase with mindfulness and reorientation of attention and (2) decrease with the experience of chronic neuropathic pain. By contrast, the control group's decreases in GMV may be due to the negative effects of CNP which potentially may be reduced with MBSR, though further research is needed.

IMPLICATIONS FOR CANCER SURVIVORS

Given the poor efficiency of pharmacotherapies in a high percentage of women with neuropathic pain following breast cancer treatment, adjunct methods are required. MBSR may affect the brain to help alter attention and perception of pain, thus playing a potentially important role in the path to wellness for breast cancer survivors.

Effective Treatment of Chronic Mastectomy Pain with Intercostal Sensory Neurectomy

SUMMARY

Chronic postmastectomy pain affects up to 40 percent of patients and leads to diminished quality of life and increased risk of opioid dependence. The cause of this pain is incompletely understood; however, one hypothesis is that direct injury to cutaneous intercostal nerves at the time of mastectomy and/or reconstruction leads to chronic pain. As a result, proximal neurectomy of the involved sensory nerve(s) has been suggested to be effective for these patients. The purpose of this study was to determine whether chronic pain in postmastectomy patients can be diagnosed reliably in an office setting and pain reduced by intercostal sensory neurectomy. The authors performed a retrospective review of seven patients with a history of breast surgery and chronic pain who underwent intercostal neurectomy combined with muscle or dermal wrapping of the proximal end of the resected nerve. All patients were diagnosed by history and physical examination, and suspected nerves were further identified with local anesthetic nerve blocks. An average of 3.14 neurectomies were performed per patient (range, one to six). There was a significant reduction in visual analogue scale pain scores following surgery, from 9 preoperatively to 1 postoperatively (p = 0.02). Eighty-six percent of patients were pain-free or "considerably improved" at their latest follow-up appointment (average, 6.14 months). It is concluded that intercostal sensory nerve injury at the time of mastectomy and/or reconstruction can lead to chronic mastectomy pain, which can be easily diagnosed and effectively treated with intercostal neurectomy.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Risk factors for persistent pain after breast and thoracic surgeries: a systematic literature review and meta-analysis

ABSTRACT

Persistent postsurgical pain (PPSP) is common after breast and thoracic surgeries. Understanding which risk factors consistently contribute to PPSP will allow clinicians to apply preventive strategies, as they emerge, to high-risk patients. The objective of this work was to systematically review and meta-analyze the literature on risk factors of PPSP after breast and thoracic surgeries. A systematic literature search using Ovid Medline, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Embase, PsycINFO, and Scopus databases was conducted. Study screening with inclusion and exclusion criteria, data extraction, and risk of bias assessment was performed independently by 2 authors. The data for each surgical group were analyzed separately and meta-analyzed where possible. The literature search yielded 5584 articles, and data from 126 breast surgery and 143 thoracic surgery articles were considered for meta-analysis. In breast surgery, younger age, higher body mass index, anxiety, depression, diabetes, smoking, preoperative pain, moderate to severe acute postoperative pain, reoperation, radiotherapy, and axillary lymph node dissection were the main factors associated with higher risk of PPSP. In thoracic surgery, younger age, female sex, hypertension, preoperative pain, moderate to severe acute postoperative pain, surgical approach, major procedure, and wound complications were associated with PPSP. This systematic review demonstrated certain consistent risk factors of PPSP after breast and thoracic surgeries, as well as identified research gaps. Understanding the factors that increase susceptibility to PPSP can help selectively allocate resources to optimize perioperative care in high-risk patients and help develop targeted, risk-stratified interventions for PPSP prevention.

"Post Mastectomy Pain Syndrome: A Systematic Review of Prevention Modalities"

Background

Post-mastectomy pain syndrome (PMPS) is a surgical complication of breast surgery characterized by chronic neuropathic pain. The development of PMPS is multifactorial and research on its prevention is limited. The objective of this systematic review is to synthesize the existing evidence on interventions for lowering the incidence of persistent neuropathic pain after breast surgery.

Methods

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we performed a comprehensive search of the electronic databases of MEDLINE, Cochrane Library, Embase, CINAHL, PsycINFO, Web of Science, and ClinicalTrials.gov using a combination of database-specific controlled vocabulary and keyword searches. Two reviewers independently screened all unique records. Publications on chronic (>3-month duration) pain after breast cancer-related surgery were included. Studies were classified by modality.

Results

Our literature search yielded 7092 articles after deduplication. We identified 45 studies that met final inclusion criteria for analysis, including 37 randomized-controlled trials. These studies revealed seven major intervention modalities for prevention of PMPS: physical therapy, mindfulness-based cognitive therapy, oral medications, surgical intervention, anesthesia, nerve blocks, and topical medication therapy.

Conclusion

High-quality data on preventative techniques for PMPS are required to inform decisions for breast cancer survivors. We present a comprehensive assessment of the modalities available that can help guide breast and reconstructive surgeons employ effective strategies to lower the incidence and severity of PMPS. Our review supports the use of multimodal care involving both a peripherally targeted treatment and centrally acting medication to prevent the development of PMPS.

Advances in Oncoanaesthesia and Cancer Pain

INTRODUCTION

The growing interest on how peri-‑operative interventions, especially regional anesthesia, during cancer surgery can alter oncological outcome increasing disease free survival is probably responsible for the birth of the new subspecialty called onco-anesthesia. A paradigm shift in the concept of anesthetic management has occurred recently owing to the innumerable diverse revelations from the ongoing research in this field.

DISCUSSION

Long lasting but reversible epigenetic changes can occur due to surgical stress and perioperative anesthetic medications. The exact relationship between these factors and tumor biology is being studied further. A popular topic under research now is the influence of regional anesthesia on cancer recurrence. Combining nerve blocks with total intravenous anesthesia (TIVA) brings down the requirement of opioids and volatile anesthetic agents implicated in cancer recurrence. The study of mechanism of pain at the molecular level has led to the discovery of novel modes of prevention of chronic post-surgical pain. Newer combination aggressive treatment therapies -intraoperative chemotherapy and radiotherapy, isolated limb perfusion, photodynamic therapy and robotic surgery require specialized anesthetic management. The COVID pandemic introduced new guidelines for safe management of oncosurgical patients .Use of genomic mapping to personalize pain management will be the breakthrough of the decade.

CONCLUSION

The discovery that anesthetic strategy could have significant oncological sequel is a quantum leap forward. Avoiding some anesthetic medications may decrease cancer recurrence. Comprehensive cancer care and translational research will pave the way to uncover safe anesthetic practices.

Health-Related Suffering and Palliative Care in Breast Cancer

Purpose of Review

Breast cancer continues to be the most frequently diagnosed cancer in women and the leading cause of cancer death worldwide. By the suffering that it causes in various domains of life, breast cancer seriously impacts the quality of life of affected individuals and causes a major burden of suffering in the community. The objectives of the review were to understand the health-related suffering in patients with breast cancer and to identify the scope of palliative care in improving the quality of life of patients with breast cancer.

Recent Findings

Breast cancer causes suffering in physical, psychological, social, financial, and spiritual domains of the lives of the patient and family. Management of breast cancer with surgery, chemotherapy, and radiation could have adverse effects, such as pain, nausea and vomiting, fatigue, shortness of breath, depression, and constipation. Both cancer and its treatment can impact the psychosocial and spiritual well-being of the patient and family members. Integrating palliative care into existing breast cancer treatment programs seems to be the best approach to diminish these sufferings.

Summary

In addition to pain and other physical symptoms, breast cancer can cause major psychological, social, and spiritual suffering. In the context of developing countries, out-of-pocket expenditure can cause major financial destruction which can impact generations. Integration of palliative care to breast cancer treatment is essential.

Integrative surgical oncology: A model of acute integrative oncology

Integrative oncology has emerged as a recognized medical subspecialty because of growing interest in the use of integrative medicine in modern cancer care on behalf of both patients and providers. Acutherapy and mind-body techniques, such as meditation and yoga, have been shown to aid in symptom control and improve quality of life in oncologic patient populations, and the Society of Integrative Oncology and American Society of Clinical Oncology have recently endorsed a set of guidelines for the implementation of these techniques specifically in patients with breast cancer. Although the current guidelines focus largely on the management of chronic symptoms, there exists evidence to support the use of these techniques in acute symptom management as well. With surgical resection representing the backbone of many cancer treatment regimens, symptoms that arise during the perioperative period are prime examples of the acute symptomatology common among patients with cancer. Here, the authors provide a detailed literature review of the current evidence supporting the use of integrative techniques during the perioperative period and demonstrate their applicability for acute symptom management within oncologic and surgical populations. In doing so, the authors introduce a new paradigm of surgical practice they call integrative surgical oncology and integrative surgery.

Patient Perspective on Post-Breast Reconstruction Exercise and Physical Therapy

Background

Breast reconstruction may result in significant functional compromise and pain. Postoperative exercise and physical therapy can mitigate these morbidities, but it is infrequently recommended by healthcare providers. This study asked how many breast reconstruction patients are instructed to perform postoperative at-home exercises or physical therapy, how many reported following through with these instructions, and what timeline they were given for these activities.

Methods

A 16-question multiple-choice anonymous online survey was distributed to a private breast cancer survivor Facebook group (Diep C. Foundation).

Results

A total of 150 breast reconstruction patients responded to our survey. The majority of respondents in our sample were not provided with specific instructions regarding postoperative at-home exercises (N = 70, 54.3%) or physical therapy (N = 77, 63.6%). Approximately 13 of 59 respondents (22%) who had been instructed to participate in postoperative at-home exercises were directed to begin at 2-3 weeks. Approximately 15 of 44 respondents (34.1%) who had been instructed to participate in physical therapy were directed to begin these at 4-5 weeks.

Conclusions

To the best of our knowledge, this is the first study of how often postoperative at-home exercises and physical therapy are recommended to breast reconstruction patients. Despite robust evidence of these activities' benefits, most women are not instructed to participate in postoperative at-home exercises or physical therapy. This is likely to impede breast reconstruction patients' recovery and delay their return to activities of daily living. More studies are needed of how to actively engage breast reconstruction patients in postoperative at-home exercises and physical therapy.

A Targeted Approach to Post-Mastectomy Pain and Persistent Pain following Breast Cancer Treatment

Persistent pain following treatment for breast cancer is common and often imprecisely labeled as post-mastectomy pain syndrome (PMPS). PMPS is a disorder with multiple potential underlying causes including intercostobrachial nerve injury, intercostal neuromas, phantom breast pain, and pectoralis minor syndrome. Adding further complexity to the issue are various musculoskeletal pain syndromes including cervical radiculopathy, shoulder impingement syndrome, frozen shoulder, and myofascial pain that may occur concurrently and at times overlap with PMPS. These overlapping pain syndromes may be difficult to separate from one another, but precise diagnosis is essential, as treatment for each pain generator may be distinct. The purpose of this review is to clearly outline different pain sources based on anatomic location that commonly occur following treatment for breast cancer, and to provide tailored and evidence-based recommendations for the evaluation and treatment of each disorder.

Pain in the Cancer Survivor

Recent decades have demonstrated significant strides in cancer screening, diagnostics and therapeutics. As such there have been dramatic changes in survival following a diagnosis of cancer.

Trigger point injection for post-mastectomy pain: a simple intervention with high rate of long-term relief

Post-mastectomy pain syndrome (PMPS) is a common and often debilitating condition. The syndrome is defined by chest wall pain unresponsive to standard pain medications and the presence of exquisite point tenderness along the inframammary fold at the site of the T4 and T5 cutaneous intercostal nerve branches as they exit from the chest wall. Pressure at the site triggers and reproduces the patient's spontaneous or motion-evoked pain. The likely pathogenesis is neuroma formation after injury to the T4 and T5 intercostal nerves during breast surgery. We assessed the rate of long-term resolution of post-mastectomy pain after trigger point injections (2 mL of 1:1 mixture of 0.5% bupivacaine and 4 mg/mL dexamethasone) to relieve neuropathic pain in a prospective single-arm cohort study. Fifty-two women (aged 31-92) who underwent partial mastectomy with reduction mammoplasty or mastectomy with or without reconstruction, and who presented with PMPS were enrolled at the University of California San Francisco Breast Care Center from August 2010 through April 2018. The primary outcome was a long-term resolution of pain, defined as significant or complete relief of pain for greater than 3 months. A total of 91 trigger points were treated with mean follow-up 43.9 months with a 91.2% (83/91) success rate. Among those with a long-term resolution of pain, 60 trigger points (72.3%) required a single injection to achieve long-lasting relief. Perineural infiltration with bupivacaine and dexamethasone is a safe, simple, and effective treatment for PMPS presenting as trigger point pain along the inframammary fold.

Post-Breast Surgery Pain Syndrome: Shifting a Surgical Paradigm

Post-mastectomy pain syndrome and the less well-described post-breast surgery pain syndrome are long-term neuropathic pain conditions that may affect more than 50% of patients after mastectomy and breast surgery. While the etiology, risk factors, and management have been reviewed in our literature, we offer here a focused outline that will gear the plastic surgeon with tools to lead a multidisciplinary, algorithmic approach to the care of patients with post-mastectomy pain syndrome/post-breast surgery pain syndrome. After reading this article, we hope the reader will have improved awareness of post-mastectomy pain syndrome/post-breast surgery pain syndrome, and thus be able to incorporate appropriate treatments and preventative steps into their primary surgical routine.

Publication Trends and Hot Spots in Chronic Postsurgical Pain (CPSP) Research: A 10-Year Bibliometric Analysis

Purpose

Aging populations and increasing quality of life requirements have attracted growing efforts to study chronic postsurgical pain (CPSP). However, a diverse range of factors are involved in CPSP development, which complicates efforts to predict and treat this disease. To advance research in this field, our study aimed to use bibliometric analysis to quantitatively and qualitatively evaluate CPSP research and predict research hot spots over the last 10 years.

Methods

Relevant publications between 2011 and 2020 were extracted from the Web of Science Core Collection database. CiteSpace software (v5.7.R2) and the Online Analysis Platform of Literature Metrology were used to analyze research attributes including countries and authors, keywords and co-occurrence, and burst detection to predict trends and hot spots.

Results

A total of 2493 publications were collected with the number of annual publications showing nearly threefold increase over the past decade. Articles were the primary publication type with the United States as the leading country and the center of national collaboration. Johns Hopkins University provided the leading influence within the CPSP field. Postoperative pain, multimodal analgesia, quality of life, opioid, microglia, cesarean delivery, inguinal hernia, chronification, genetic polymorphism, and lidocaine were the top 10 clusters in co-occurrence cluster analysis. Moreover, burst detection was shown that epidural analgesia, nerve injury, total hip arthroplasty were the new hot spots within the CPSP field.

Conclusion

Bibliometric mapping not only defined the overall structure of CPSP-related research but its collective information provides crucial assistance to direct ongoing research efforts. The prominent keywords including "risk factor" and "multimodal analgesia" indicate that CPSP prevention and new treatment methods remain hot spots. Nonetheless, the recognition that CPSP is complex and changeable, proposes comprehensive biopsychosocial approaches are needed, and these will be essential to improve CPSP interventions and outcomes.

A cross-sectional study of breast pain in a diverse population of breast cancer patients

BACKGROUND

Breast cancer is the most common cancer in women, and postoperative breast pain has been reported to be anywhere from 25% to 60%. However, there is sparse data regarding racial/ethnic differences in breast pain among breast cancer patients.

METHODS

We performed a cross-sectional anonymous survey of breast cancer patients from the Hawaii Cancer Consortium over a 6-week period between 2019 and 2020. The 237 breast cancer participants were ages 29 to 98, 74% Asian, and mainly from outpatient oncology clinics. We evaluated the prevalence of breast pain in a diverse group of breast cancer patients and characterized the pain using a modified short-form McGill pain questionnaire (sfMPQ).

RESULTS

Eighty-fourrespondents(35.4%) reported breast pain. On univariable analysis, we found significant racial/ethnic differences in the amount of breast pain, where Chinese and Japanese participants reported significantly less pain compared to White participants on a 10-point pain scale. We found differences in breast pain according to age and endocrine therapy use as well as survey location, however, no differences were seen according to chemotherapy, radiation, or breast surgery. Based on the sfMPQ, the most common descriptors of breast pain were sensory (throbbing, shooting, and stabbing) compared to affective (tiring-exhausting, sickening, fearful, and punishing-cruel) characteristics. Although they were described as mild and intermittent, in women with breast pain, 33.4% reported the breast pain affected their sleep, 16.7% their work, and 15.4% their sexual activity.

CONCLUSIONS

Breast pain is a significant problem in our breast cancer community. This survey assessment has informed our understanding of breast pain in our diverse population. In turn, we are developing culturally appropriate pain management strategies to treat this challenging symptom common in breast cancer survivors.

Pain Management in Breast Cancer Patients: A Multidisciplinary Approach

Pain is a significant problem and is one of the most invalidating symptoms in breast cancer (BC) patients that would negatively affect the functional status and the Quality of Life (QoL). Pain management in BC patients requires thorough patient evaluation and critical assessment of pain. The actual cause for the pain must be recognized, so management can be tailored to each patient. This review aims to discuss various treatment modalities employed for effectively managing pain in BC patients.

Pharmacotherapy makes up the cornerstone of the management of pain in BC patients. Both opioid and non-opioid analgesics are utilized. The WHO recommends a method called “by the ladder” for managing pain in BC patients where analgesics are used in ascending order. In comprehensive pain management (CPM), non-pharmacologic therapies are gaining wide acceptance and popularity, including complementary and alternative medicine (CAM), procedural and psychosocial interventions. Procedural interventions are usually used in case of severe pain refractory to pharmacological therapy. Techniques, such as radiotherapy, neurectomy, and nerve blocks, are effective in managing cancer pain. However, CAM therapies in BC pain management need to be guided by enough scientific evidence, decision-making, and medical judgment of regulatory bodies.

BC pain management is based on careful routine pain assessments and appropriate patient evaluation both physically and psychologically. Pain control is one of the methods to improve the QoL of BC patients. Both pharmacological and non-pharmacological therapies are accessible to patients today, but they should be used with caution to minimize toxicity and increase effectiveness. The use of any pain management intervention should be based on proper scientific evidence and collective medical judgment.

The Mechanisms of Action of Botulinum Toxin Type A in Nociceptive and Neuropathic Pathways in Cancer Pain

BACKGROUND

Botulinum toxin type A (BoNT-A) is widely employed for cosmetic purposes and in the treatment of certain diseases such as strabismus, hemifacial spasm and focal dystonia among others. BoNT-A effect mainly acts at the muscular level by inhibiting the release of acetylcholine at presynaptic levels consequently blocking the action potential in the neuromuscular junction. Despite the great progress in approval and pharmaceutical usage, improvement in displacing BoNT-A to other pathologies has remained very limited. Patients under diagnosis of several types of cancer experience pain in a myriad of ways; it can be experienced as hyperalgesia or allodynia, and the severity of the pain depends, to some degree, on the place where the tumor is located. Pain relief in patients diagnosed with cancer is not always optimal, and as the disease progresses, transition to more aggressive drugs, like opioids is sometimes unavoidable. In recent years BoNT-A employment in cancer has been explored, as well as an antinociceptive drug; experiments in neuropathic, inflammatory and acute pain have been carried out in animal models and humans. Although its mechanism has not been fully known, evidence has shown that BoNT-A inhibits the secretion of pain mediators (substance P, Glutamate, and calcitonin gene related protein) from the nerve endings and dorsal root ganglion, impacting directly on the nociceptive transmission through the anterolateral and trigeminothalamic systems.

AIM

The study aimed to collect available literature regarding molecular, physiological and neurobiological evidence of BoNT-A in cancer patients suffering from acute, neuropathic and inflammatory pain in order to identify possible mechanisms of action in which the BoNT-A could impact positively in pain treatment.

CONCLUSION

BoNT-A could be an important neo-adjuvant and coadjuvant in the treatment of several types of cancer, to diminish pro-tumor activity and secondary pain.

Breast Reconstruction Does Not Increase the Incidence of Postmastectomy Pain Syndrome: Results of a Meta-Analysis

BACKGROUND

Postmastectomy pain syndrome (PMPS) is characterized by neuropathic pain from direct nerve injury during oncologic breast surgery causing chronic pain, often leading to chronic opioid dependence and long-term disability. To our knowledge, this study represents the first meta-analysis that defines the incidence of PMPS in patients undergoing mastectomy, with and without breast reconstruction.

METHODS

The Cochrane, Embase, MEDLINE, and PubMed databases were queried. A total of 166 citations from 1991 to 2017 were reviewed to identify 22 unique manuscripts. Inclusion criteria required: (i) minimum 3-month follow-up, (ii) pain in breast, (iii) pain after mastectomy, (iv) documentation of any reconstruction, and (v) minimum of level three evidence. Comprehensive Meta- Analysis Software and Microsoft Excel were used for statistical calculations.

RESULTS

Sixteen manuscripts described the prevalence of postmastectomy pain and 11 described the prevalence of postreconstruction pain (5 had data for both). Study population size ranged from 32 to 1165 patients. All studies were classified as level 2 or level 3 evidence. The mean prevalence of pain after mastectomy alone using a random-effects model is 35.6% (30.3%-41.3%). Mean prevalence of pain after mastectomy with reconstruction using the random-effects model is 32.8% (24.4% - 42.5%). Analysis of variance analysis showed no significant difference between prevalence of chronic pain after mastectomy alone versus mastectomy and reconstruction (P = 0.88).

CONCLUSIONS

Our meta-analysis establishes that postmastectomy reconstruction does not increase the incidence of PMPS. However, because this neuropathic pain often persists after reconstructive surgery, it is incumbent on the plastic surgeon to counsel patients on PMPS. Moving forward, prospective studies on the effects of reconstruction type and adjunct procedures are warranted.

Postmastectomy pain syndrome after preoperative stellate ganglion block: a randomized controlled trial

BACKGROUND

This study investigated the effect of preoperative ultrasound (US) guided stellate ganglion block (SGB) with bupivacaine on the frequency of post mastectomy pain syndrome (PMPS).

METHODS

Eighty patients scheduled for mastectomy with axillary dissection for breast cancer were included in this randomized controlled trial. Patients were randomized into two equal groups: Group A received US guided SGB one hour before surgery using five mL of 0.5% bupivacaine and multimodal systemic analgesia, Group B (control) received multimodal systemic analgesia only. Patients were followed up for six months. PMPS was assessed using the grading system for neuropathic pain (GSNP). Postoperative opioid consumption in the first 24 hours and numeric rating scale (NRS) were documented. Patient daily activity and functional capacity were evaluated using the Eastern Cooperative Oncology Group (ECOG) score.

RESULTS

PMPS proportion was significantly lower in group A than group B (30% vs. 62.5%, P=0.004; 52% decrease [95% CI: 18.4%-71.8%]). Postoperative opioid consumption and NRS were significantly lower in group A as compared to group B. ECOG score was significantly higher in Group A than Group B.

CONCLUSIONS

Following mastectomy with axillary dissection, preoperative US guided SGB is associated with less PMPS proportion, postoperative pain and opioid consumption and better patient daily activity and functional capacity.

Post-mastectomy pain syndrome: A timely review of its predisposing factors and current approaches to treatment

Background:

Post-mastectomy pain syndrome (PMPS) has been reported to occur in 25–60% of patients following surgeries for breast cancer, the highest occurring cancer in women worldwide. There has been much research interest due to this high prevalence. However, there is still a lack of incorporation of PMPS prevention strategies in standard perioperative plans, and our understanding of this condition is still incomplete.

Objectives:

This narrative review discusses recent literature on modifiable risk factors, current approaches to prevention and treatment and potential directions for future treatment and research.

Methods:

A PubMed search with the relevant keywords was done for articles published in the last 10 years.

Results:

The incidence of PMPS can be reduced by early recognition and management of modifiable risk factors as well as the perioperative use of analgesics and regional nerve blocks. These also have a significant role in the management of established PMPS together with surgical interventions and physical therapy.

Conclusions:

PMPS is still poorly defined and hence underdiagnosed and undertreated at this point. Perioperative peripheral nerve blocks have a very promising role as preventive analgesia to reduce the risk of developing PMPS, but large-scale randomised controlled studies will need to be done to evaluate their comparative efficacy. There is a need to prioritise PMPS prevention as a standard inclusion into the perioperative plans of mastectomy patients.

Problems in living among breast cancer survivors

Purpose:

Breast cancer survivors may experience worse social, physical, and emotional function compared to the general population, although symptoms often improve over time. Data on problems in living can help to improve interventions and supportive care for breast cancer survivors. Symptoms such as fatigue, pain, difficulties with sleep, and sexual problems may have an adverse effect on the quality of life of breast cancer survivors.

Methods:

We examined problems in living using data from a survey of 164 breast cancer survivors who had completed primary therapy for the disease.

Results:

A total of 164 women completed the study questions (response rate 16.4%). The mean age of the women was 67 years. Among all participants, 66.7% were white, 29.5% were African-American, and the remainder were of other races. Almost all of the symptoms were more likely to be reported by participants who were < 55 years of age. Other important correlates of symptoms included non-white race, marital status, and having a household income of less than $50,000 per year.

Conclusion:

The results of this study highlight the need for caregivers to emphasize screening for and discussion of symptoms, including sleep difficulties, fatigue, loss of strength, aches and pains, and muscle or joint stiffness. Of particular concern are younger survivors and those who are African American or low-income.

Cancer and Peripheral Nerve Disease

Patients with cancer may experience neuropathy at any stage of malignancy, ranging from symptoms that are the earliest signs of cancer to side effects of treatment. Peripheral nerves are affected most commonly in a symmetric, stocking-glove pattern. Sensory neuronopathies, plexopathies, and radiculopathies may also be seen. The most common type of neuropathy in patients with cancer is related to chemotherapy, and recently peripheral nerve complications have been described as an effect of immune checkpoint inhibitors too. Other causes include paraneoplastic syndromes, direct tumor infiltration, and radiation. Treatment focuses on addressing the underlying cancer and management of neuropathic pain.

Reliability and validity of the Upper Limb Functional Test (ULIFT) for women after breast cancer surgery

PURPOSE

To evaluate the reliability and convergent validity of the Upper Limb Functional Test (ULIFT) in women after breast cancer surgery.

MATERIALS AND METHODS

A cross-sectional study with 25 women (mean age 50 ± 7.3 years) with breast cancer submitted to a surgery intervention within a minimum period of three years. Intraclass correlation coefficients (ICCs) were calculated to assess the test-retest reliability. A Bland-Altman plot examined the agreement between the times to complete two tests. Validity was established by correlating the ULIFT and DASH total score. The receiver operating characteristic (ROC) curve was used to determine the cut-off point for ULIFT in order to discriminate patients with some level of upper limb dysfunction.

RESULTS

The ULIFT showed high reproducibility (ICC = 0.89; p < 0.001), learning effect of 7.21%, and a moderate correlation with the DASH total score (r = 0.536; R² = 0.28; p = 0.006). The standard error of measurement was 6.9 s and the smallest real difference was 19.1 s. The ROC curve indicated a cut-off point of 109.2 s (sensitivity = 68.7%; specificity = 77.8%; area under ROC curve = 0.77).

CONCLUSIONS

The ULIFT could be a valid and reliable test to assess upper limb functionality in patients submitted to breast cancer surgery.Implications for rehabilitationThe ULIFT is a reliable and valid test to assess upper limb function in women after breast cancer surgery, considering specifically the lifting and range of motion construct of unilateral upper limb function.The ULIFT could help identify those most at risk of developing upper limb dysfunction after breast cancer surgery and could benefit the follow-up of a postoperative rehabilitation program.Two ULIFTs should be performed in order to achieve patient's best performance.

Chronic pain after breast surgery: incidence, associated factors, and impact on quality of life, an observational prospective study

BACKGROUND

Chronic pain after breast surgery (CPBS) has a disabling impact on postoperative health status. Mainly because of the lack of a clear definition, inconsistency does exist in the literature concerning both the actual incidence and the risk factors associated to CPBS. The aim of this prospective, observational study is to describe the incidence of and risk factors for CPBS, according to the definition provided by the IASP taskforce. The impact of CPBS on patients' function and quality of life is also described.

METHODS

Women aged 18+ undergoing oncological or reconstructive breast surgery from Jan until Apr 2018 at the Breast Unit of Careggi Hospital (Florence, Italy) were prospectively observed. Postoperative pain was measured at 0 h, 3 h, 6 h, 12 h, 24 h, 48 h, and 3 months (CPBS) after surgery. Preoperative, intraoperative, and postoperative factors were compared in CPBS and No-CPBS groups through multivariate logistic regression analysis.

RESULTS

Among the 307 patients considered in this study, the incidence of CPBS was 28% [95% CI 23.1-33.4%]. Results from the logistic regression analysis suggest that axillary surgery (OR [95% CI], 2.99 [1.13-7.87], p = 0.03), preoperative use of pain medications (OR [95% CI], 2.04 [1.20-3.46], p = 0.01), and higher dynamic NRS values at 6 h postoperatively (OR [95% CI], 1.28 [1.05-1.55], p = 0.01) were all independent predictors for CPBS.

CONCLUSIONS

Chronic pain after breast surgery is a frequent complication. In our cohort, long-term use of analgesics for pre-existing chronic pain, axillary surgery, and higher dynamic NRS values at 6 h postoperatively were all factors associated with increased risk of developing CPBS. The possibility to early detect persistent pain, particularly in those patients at high risk for CPBS, might help physicians to more effectively prevent pain chronicisation.

TRIAL REGISTRATION

ClinicalTrials.gov registration NCT04309929 .

Behavioral cancer pain intervention using videoconferencing and a mobile application for medically underserved patients: Rationale, design, and methods of a prospective multisite randomized controlled trial

BACKGROUND

Women with breast cancer in medically underserved areas are particularly vulnerable to persistent pain and disability. Behavioral pain interventions reduce pain and improve outcomes. Cancer patients in medically underserved areas receive limited adjunctive cancer care, as many lack access to pain therapists trained in behavioral interventions, face travel barriers to regional medical centers, and may have low literacy and limited resources. mHealth technologies have the potential to decrease barriers but must be carefully adapted for, and efficacy-tested with, medically underserved patients. We developed an mHealth behavioral pain coping skills training intervention (mPCST-Community). We now utilize a multisite randomized controlled trial to: 1) test the extent mPCST-Community reduces breast cancer patients' pain severity (primary outcome), pain interference, fatigue, physical disability, and psychological distress; 2) examine potential mediators of intervention effects; and 3) evaluate the intervention's cost and cost-effectiveness.

METHODS/DESIGN

Breast cancer patients (N = 180) will be randomized to mPCST-Community or an attention control. mPCST-Community's four-session protocol will be delivered via videoconferencing at an underserved community clinic by a remote pain therapist at a major medical center. Videoconference sessions will be supplemented with a mobile application. Participants will complete self-report measures at baseline, post-intervention, and 3- and 6-month follow-ups.

CONCLUSIONS

mPCST-Community has the potential to reduce pain and disability, and decrease barriers for cancer patients in medically underserved areas. This is one of the first trials to test an mHealth behavioral cancer pain intervention developed specifically for medically underserved communities. If successful, it could lead to widespread implementation and decreased health disparities.

Paravertebral block for the prevention of chronic postsurgical pain after breast cancer surgery

Patients frequently report chronic postsurgical pain (CPSP) after breast cancer surgery (BCS). The paravertebral block (PVB) is an effective technique to reduce acute postoperative pain after BCS, but its efficacy in preventing CPSP is unclear. This meta-analysis evaluates the efficacy of PVB in preventing CPSP after BCS. We searched Medline, Embase, CENTRAL, Database of Abstracts of Reviews of Effects, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform for studies comparing PVB with control for CPSP prevention after BCS, from inception to April 2020. The primary outcome was CPSP at 6 months, and the secondary outcomes were CPSP at 3 and 12 months, chronic postsurgical neuropathic pain (CPSNP) at 6 months, and PVB-related complications. Data were pooled and analyzed with a random-effects model, and the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system was used to evaluate the certainty of evidence. A total of 12 studies were included in the study; data for the 6-month time point from 7 studies (2161 patients) were analyzed, and no difference was found between PVB and control in terms of efficacy in preventing CPSP after BCS (risk ratio (RR) 0.82 (95% CI 0.62 to 1.08)), with a moderate quality of evidence according to the GRADE system. Similar results were obtained at 3 and 12 months (RR 0.78 (95% CI 0.57 to 1.06), RR 0.45 (95% CI 0.14 to 1.41), respectively). Data for the 12-month time point from seven studies (2087 patients) were analyzed and showed that PVB protected against CPSNP, with low quality of evidence (RR 0.51 (95% CI 0.31 to 0.85)). In conclusion, CPSP was not found significantly prevented by PVB after BCS despite the limits in the included studies; nevertheless, PVB could prevent CPSNP by impacting the transition from acute to chronic pain.

Relationships of sleep disturbance, intestinal microbiota, and postoperative pain in breast cancer patients: a prospective observational study

Purpose

Our study was designed to examine the possible relationship between gut microbiota, sleep disturbances, and acute postoperative pain.

Methods

Using 16S rRNA sequencing, we analyzed preoperative fecal samples from women undergoing breast cancer surgery. Preoperative sleep disturbance was evaluated with the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Peak and average pain at rest and movement were evaluated 24 h after surgery, using a numerical rating scale (NRS). Preoperative symptoms of depression and anxiety were assessed with the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7), respectively. Inflammation was measured using white blood cell and neutrophil counts, together with platelet-lymphocyte ratio, and neutrophil-lymphocyte ratio.

Results

Preoperative sleep disturbance was associated with more severe acute postoperative pain. At the phylum level, women with poor sleep quality had higher relative abundance of Firmicutes (p = 0.021) and lower relative abundance of Bacteroidetes (p = 0.013). At the genus level, women with poor sleep quality harbored higher relative abundance of Acidaminococcus and lower relative abundance of several genera. The genus Alloprevotella was negatively associated with peak pain at movement during the first 24 h (r = − 0.592, p < 0.001). The genus Desulfovibrio was negatively associated with symptoms of anxiety (r = − 0.448, p = 0.006). However, partial correlations suggested that the relationship between Alloprevotella and peak pain at movement during the first 24 h was not statistically significant after controlling for sleep (r = − 0.134, p = 0.443).

Conclusion

These findings suggest that the changed gut microbiota may be involved in sleep-pain interaction and could be applied as a potential preventive method for postoperative pain.

Trial registration

The present clinical study has been registered on Chinese Clinical Trial Registry (www.chictr.org.cn); the clinical trial registration number is ChiCTR1900021730; the date of registration is March 7, 2019.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11325-020-02246-3.