Predictors of persistent pain after breast cancer surgery: a systematic review and meta-analysis of observational studies

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.

Current axillary management of patients with early breast cancer and low-volume nodal disease undergoing primary surgery: results of a United Kingdom national practice survey

PURPOSE

UK NICE guidelines recommend axillary node clearance (ANC) should be performed in all patients with biopsy-proven node-positive breast cancer having primary surgery. There is, however, increasing evidence such extensive surgery may not always be necessary. Targeted axillary dissection (TAD) may be an effective alternative in patients with low-volume nodal disease who are clinically node negative (cN0) but have abnormal nodes detected radiologically. This survey aimed to explore current management of this group to inform feasibility of a future trial.

METHODS

An online survey was developed to explore current UK management of patients with low-volume axillary disease and attitudes to a future trial. The survey was distributed via breast surgery professional associations and social media from September to November 2022. One survey was completed per unit and simple descriptive statistics used to summarise the results.

RESULTS

51 UK breast units completed the survey of whom 78.5% (n = 40) reported performing ANC for all patients with biopsy-proven axillary nodal disease having primary surgery. Only 15.7% of units currently performed TAD either routinely (n = 6, 11.8%) or selectively (n = 2, 3.9%). There was significant uncertainty (83.7%, n = 36/43) about the optimal surgical management of these patients. Two-thirds (n = 27/42) of units felt an RCT comparing TAD and ANC would be feasible.

CONCLUSIONS

ANC remains standard of care for patients with low-volume node-positive breast cancer having primary surgery in the UK, but considerable uncertainty exists regarding optimal management of this group. This survey suggests an RCT comparing the outcomes of TAD and ANC may be feasible.

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.

The gut microbiota in persistent post-operative pain following breast cancer surgery

Persistent post-surgical pain (PPSP) is defined as pain which continues after a surgical operation in a significant form for at least three months (and is not related to pre-existing painful conditions). PPSP is a common, under-recognised, and important clinical problem which affects millions of patients worldwide. Preventative measures which are currently available include the selection of a minimally invasive surgical technique and an aggressive multimodal perioperative analgesic regimen. More recently, a role for the gut microbiota in pain modulation has become increasingly apparent. This study aims to investigate any relationship between the gut microbiota and PPSP. A prospective observational study of 68 female adult patients undergoing surgery for management of breast cancer was carried out. Stool samples from 45 of these patients were obtained to analyse the composition of the gut microbiota. Measures of pain and state-trait anxiety were also taken to investigate further dimensions in any relationship between the gut microbiota and PPSP. At 12 weeks postoperatively, 21 patients (51.2%) did not have any pain and 20 patients (48.8%) reported feeling pain that persisted at that time. Analysis of the gut microbiota revealed significantly lower alpha diversity (using three measures) in those patients reporting severe pain at the 60 min post-operative and the 12 weeks post-operative timepoints. A cluster of taxa represented by Bifidobacterium longum, and Faecalibacterium prausnitzii was closely associated with those individuals reporting no pain at 12 weeks postoperatively, while Megamonas hypermegale, Bacteroides pectinophilus, Ruminococcus bromii, and Roseburia hominis clustered relatively closely in the group of patients fulfilling the criteria for persistent post-operative pain. We report for the first time specific associations between the gut microbiota composition and the presence or absence of PPSP. This may provide further insights into mechanisms behind the role of the gut microbiota in the development of PPSP and could inform future treatment strategies.

Prevention of persistent pain with lidocaine infusions in breast cancer surgery (PLAN): study protocol for a multicenter randomized controlled trial

BACKGROUND

Persistent pain is a common yet debilitating complication after breast cancer surgery. Given the pervasive effects of this pain disorder on the patient and healthcare system, post-mastectomy pain syndrome (PMPS) is becoming a larger population health problem, especially as the prognosis and survivorship of breast cancer increases. Interventions that prevent persistent pain after breast surgery are needed to improve the quality of life of breast cancer survivors. An intraoperative intravenous lidocaine infusion has emerged as a potential intervention to decrease the incidence of PMPS. We aim to determine the definitive effects of this intervention in patients undergoing breast cancer surgery.

METHODS

PLAN will be a multicenter, parallel-group, blinded, 1:1 randomized, placebo-controlled trial of 1,602 patients undergoing breast cancer surgery. Adult patients scheduled for a lumpectomy or mastectomy will be randomized to receive an intravenous 2% lidocaine bolus of 1.5 mg/kg with induction of anesthesia, followed by a 2.0 mg/kg/h infusion until the end of surgery, or placebo solution (normal saline) at the same volume. The primary outcome will be the incidence of persistent pain at 3 months. Secondary outcomes include the incidence of pain and opioid consumption at 1 h, 1-3 days, and 12 months after surgery, as well as emotional, physical, and functional parameters, and cost-effectiveness.

DISCUSSION

This trial aims to provide definitive evidence on an intervention that could potentially prevent persistent pain after breast cancer surgery. If this trial is successful, lidocaine infusion would be integrated as standard of care in breast cancer management. This inexpensive, widely available, and easily administered intervention has the potential to reduce pain and suffering in an already afflicted patient population, decrease the substantial costs of chronic pain management, potentially decrease opioid use, and improve the quality of life in patients.

TRIAL REGISTRATION

This trial has been registered on clinicaltrials.gov (NCT04874038, Dr. James Khan. Date of registration: May 5, 2021).

A guide for addressing sexual health in breast cancer patients

PURPOSE

Sexual health concerns are common in breast cancer surgery but often overlooked. Yet, breast cancer patients want more sexual health information from their providers. We aimed to share ways for providers to address sexual health concerns with their breast cancer patients at different stages of the treatment process.

METHODS

Experts in breast cancer treatments, surgeries, and sexual health at Memorial Sloan Kettering Cancer Center assembled to review the literature and to develop the recommendations.

RESULTS

Providers should provide sexual health information for their breast cancer patients throughout the continuum of care. Conversations should be initiated by the providers and can be brief and informative. Whenever appropriate, patients should be referred to Sexual Medicine experts and/or psychosocial support. There are various recommendations and tools that can be utilized at diagnosis, endocrine and chemotherapy, and breast surgery to identify patients with sexual health concerns and to improve their sexual functioning.

CONCLUSION

In this paper, we sought to provide providers with some insights, suggestions, and tools to address sexual health concerns. We encourage healthcare providers to initiate the conversation throughout the continuum of care beginning as early as diagnosis and refer patients to additional services if available.

Peripheral magnetic stimulation for chronic peripheral neuropathic pain: A systematic review and meta-analysis

OBJECTIVES

To provide a systematic review of the literature on the effects of peripheral magnetic stimulation (PMS) in the treatment of chronic peripheral neuropathic pain.

METHODS

A systematic search of MEDLINE, EMBASE, CENTRAL, CINHAL, Web of Science, and ProQuest was conducted from inception to July 2023 to identify studies of any design published in English language that enrolled adult patients (≥18 years) that received PMS for treatment of a chronic peripheral neuropathic pain disorder (pain > 3 months).

RESULTS

Twenty-three studies were identified which included 15 randomized controlled trials (RCTs), five case series, two case reports, and one non-randomized trial. PMS regimens varied across studies and ranged from 5 to 240 min per session over 1 day to 1 year of treatment. Results across included studies were mixed, with some studies suggesting benefits while others showing no significant differences. Of nine placebo-controlled RCTs, four reported statistically significant findings in favor of PMS use. In the meta-analysis, PMS significantly reduced pain scores compared to control within 0-1 month of use (mean difference -1.64 on a 0-10 numeric rating scale, 95% confidence interval -2.73 to -0.56, p = 0.003, I2 = 94%, 7 studies [264 participants], very low quality of evidence), but not at the 1-3 months and >3 months of PMS use (very low and low quality of evidence, respectively). Minimal to no adverse effects were reported with PMS use.

DISCUSSION

There is limited and low-quality evidence to make definitive recommendations on PMS usage, however, the available data is encouraging, especially for short-term applications of this novel modality. Large high-quality randomized controlled trials are required to establish definitive efficacy and safety effects of PMS.

Interpectoral and Pectoserratus Plane Block vs. Local Anesthetic Infiltration for Partial Mastectomy: A Prospective Randomized Trial

Background

Patients undergoing breast surgery are at risk of severe postoperative pain. Several opioid-sparing strategies exist to alleviate this condition. Regional anesthesia has long been a part of perioperative pain management for these patients.

Aim

This randomized study examined the benefits of interpectoral and pectoserratus plane block (IPP/PSP), also known as pectoralis nerve plain block, compared with advanced local anesthetic infiltration.

Methods

We analyzed 57 patients undergoing partial mastectomy with sentinel node dissection. They received either an ultrasound-guided IPP/PSP block performed preoperatively by an anesthetist or local anesthetic infiltration performed by the surgeon before and during the surgery.

Results

Pain measured with the numerical rating scale (NRS) indicated no statistically significant difference between the groups (IPP/PSP 1.67 vs. infiltration 1.97; p value 0.578). Intraoperative use of fentanyl was significantly lower in the IPP/PSP group (0.18 mg vs 0.21 mg; p value 0.041). There was no statistically significant difference in the length of stay in the PACU (166 min vs 175 min; p value 0.51). There were no differences in reported postoperative nausea and vomiting (PONV) between the groups. The difference in postoperative use of oxycodone in the PACU (p value 0.7) and the use of oxycodone within 24 hours postoperatively (p value 0.87) was not statistically significant.

Conclusions

Our study showed decreased intraoperative opioid use in the IPP/PSP group and no difference in postoperative pain scores up to 24 hours. Both groups reported low postoperative pain scores. This trial is registered with NCT04824599.

Impact of Body Mass Index on Postoperative Pain and Opioid Administration After Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC)

PURPOSE

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a new surgical technique, developed for the treatment of peritoneal carcinomatosis (PC). In this retrospective observational study we assessed the impact of body mass index (BMI) on postoperative pain and opioid consumption.

METHODS

We analyzed pain scores after 100 PIPAC procedures using either oxaliplatin or doxorubicin-cisplatin performed in 49 patients with PC between July 2016 and September 2020. The patients were divided into 3 groups (BMI <18.5, 18.5 ≥ BMI < 25, BMI≥25). Pain was self-rated on a visual analogue scale (VAS) from 0 to 10.

RESULTS

Univariate logistic regression analysis identified oxaliplatin and PCI score to be associated with moderate to severe pain (VAS 4-10 at 8 am D1) after adjustment on BMI (OR [95% CI]; 3.26[1.00 - 10.65] p=0.050) and (OR [95% CI]; 1.09[1.01 - 1.17] p=0.019). The level of pain appeared significantly different between the treatment groups (median 2.5[0; 5] vs 0[0; 2.5] p=0.0017) irrespective of BMI (p =0.705 and p=0.118). Multivariate logistic regression analysis identified moderate to severe pain and synchronous PC to be associated with greater use of opioids (OR [95% CI]: 3.91 [1.24 - 12.32]) and (OR [95% CI]: 5.16 [1.71 - 15.58]; respectively. Opioids were administered after 45 procedures (45%) and was comparable between the treatment groups. Opioid administration and length-of-stay were similar among BMI bands.

CONCLUSION

BMI is not related to postoperative pain or opioid use, howevermoderate to severe pain and synchronous PC are factors associated with requiring opioids.

Can illness representations be used to understand pain experienced in breast cancer survivorship-a cross-sectional study

BACKGROUND

Chronic pain is a recognised long-term consequence associated with breast cancer and its treatment; however, it is often underdiagnosed and undertreated. This study aims to explore the associations between illness representations, chronic cancer pain, and HRQoL in women who have survived breast cancer.

DESIGN AND METHODS

A cross-sectional online survey design was used. Data from 182 women who participated in the survey were analysed.

RESULTS

Chronic cancer pain was reported by 66% of respondents. Using the BPI-SF (score 0-10), participants were categorised into one of four pain categories: no chronic pain (BPI score 0; 34.1%), mild pain (BPI score 1-3; 35.7%), moderate pain (BPI score 4-6; 25.3%), and severe pain (BPI score 7 + ; 4.9%). The main findings were that having a strong illness identity (IPQ-R subscale which assesses the number of symptoms an individual attributes to their illness) was found to be a significant predictor of pain severity (OR 1.21 (95% CI 1.07-1.37), p = 0.003). Furthermore, HRQoL was significantly associated and predictive of pain severity (OR 0.97 (95% CI 0.95-0.99), p < 0.001). An additional finding was that not being in paid work was strongly associated with being in a higher pain category (OR 5.92 (95% CI 1.84-19.05), p = 0.003).

CONCLUSIONS

The findings of this study highlight the high prevalence of chronic cancer pain experienced by this population. Results show that dimensions of illness representations are associated with chronic cancer pain experienced by breast cancer survivors. Furthermore, having a strong illness identity and HRQoL were found to be independent, significant predictors of pain severity.

IMPLICATIONS FOR CANCER SURVIVORS

These findings demonstrate that chronic pain is an unmet clinical need experienced by breast cancer survivors, which is associated with reduced overall HRQoL. Therefore, consideration is needed regarding the assessment and management of chronic pain experienced by this population.

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.

Patient Satisfaction and Quality of Recovery With Ambulatory Serratus Plane Catheter After Mastectomy: A Service Evaluation

Background Acute moderate to severe pain after mastectomy is common and impedes patient recovery. Ambulatory serratus plane catheter with infusion pump (ASPIP) is a novel method to provide continuous delivery of local anaesthetic agents in the immediate postoperative period for extended analgesia, early mobility, and return to function after mastectomy. The aim of this project was to evaluate the introduction of ASPIP service and its effect on postoperative pain, opioid use, hospital stay, and recovery. Methods This was a service evaluation project. Eligible mastectomy patients were included over six months. All patients provided consent for intraoperative catheter insertion and ASPIP use. The numerical rating scale (NRS) and the Quality of Recovery-15 (QoR-15) tool were used to assess postoperative pain and the quality of recovery, respectively. Overall satisfaction, sleep quality, and recommendations for the catheter were collected. Day-case rates of mastectomy with or without reconstruction were also measured. Data were presented using descriptive statistics. Mean (SD) and median (quartiles) were used for the continuous variables with percentages to report rates. Approval of the institution's Audit & Quality Improvement Department was obtained. Results Thirty-two consecutive mastectomy patients were included over six months. The mean age was 60 years and the mean BMI was 25.8. Mean pain NRS (10 maximum) at rest and on movement were 1.88 vs. 2.56, 2.03 vs. 2.84, and 1.85 vs. 2.3 out of 10 on postoperative day (POD) one, two, and three, respectively. Six patients required opioids on POD one, four patients on POD two, and none on the third day. Sleep disturbance was observed in three, five, and three patients in the first three days, respectively. The mean overall satisfaction was 9.25/10 (SD: 1.18). All patients recommended ASPIP to other patients. QoR-15 scores reported as median (quartiles) were 143 (136, 147) preoperatively and 135 (126.5, 143) postoperatively, with a median difference of -3 (95% CI: -6 to 0). The day-case rate for mastectomy +/- reconstruction was 66% and 39%, respectively. There were no major complications from the catheter with minor issues in four patients. Conclusion The ASPIP is an effective and safe method of managing postoperative pain after mastectomy with positive patient experience and reduced opioid requirement. As part of an enhanced recovery pathway, it can also increase mastectomy day-case rates, including immediate implant reconstruction.

Novel Prevention Approaches of Breast Cancer Surgery Related Complications: Systematic Review and Network Meta-Analysis

BACKGROUND

Breast cancer surgery related complications are a complex condition influenced by interactions among nerve pathways and the physiological responses to breast surgery. The intensity of this complications displays substantial heterogeneity, dependent on individual patient characteristics, the extent of the surgical procedure performed, and various contributing factors.

METHODS

A comprehensive search of electronic databases was conducted to identify relevant randomized controlled trials (RCTs) investigating interventions for post-mastectomy pain syndrome (PMPS). A network meta-analysis was performed to integrate direct and indirect evidence, enabling comparisons of multiple interventions across different outcome measures.

RESULTS

The systematic search yielded a total of 26 RCTs investigating 4 groups of different interventions for PMPS. The interventions included pharmacological agents, nerve blocks, physical therapy, and anesthesia regimens. Nerve blocks (OR: 0.34; 95% CrI: 0.24-0.46) and anesthesia (OR: 0.39; 95% CrI: 0.26-0.56) demonstrated improvements in functional outcomes and quality of life.

CONCLUSION

This systematic review and network meta-analysis provide a comprehensive evaluation of interventions for PMPS, highlighting their varying efficacy in alleviating pain and improving functional outcomes and quality of life. However, further research with large-scale, well-designed RCTs is warranted to strengthen the evidence base and validate the effectiveness of these interventions in managing PMPS effectively.

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.

Postmastectomy Functional Impairments

PURPOSE OF REVIEW

This narrative review aims to offer a thorough summary of functional impairments commonly encountered by breast cancer survivors following mastectomy. Its objective is to discuss the factors influencing these impairments and explore diverse strategies for managing them.

RECENT FINDINGS

Postmastectomy functional impairments can be grouped into three categories: neuromuscular, musculoskeletal, and lymphovascular. Neuromuscular issues include postmastectomy pain syndrome (PMPS) and phantom breast syndrome (PBS). Musculoskeletal problems encompass myofascial pain syndrome and adhesive capsulitis. Lymphovascular dysfunctions include lymphedema and axillary web syndrome (AWS). Factors such as age, surgical techniques, and adjuvant therapies influence the development of these functional impairments. Managing functional impairments requires a comprehensive approach involving physical therapy, pharmacologic therapy, exercise, and surgical treatment when indicated. It is important to identify the risk factors associated with these conditions to tailor interventions accordingly. The impact of breast reconstruction on these impairments remains uncertain, with mixed results reported in the literature.

Risk factors for long-term arm morbidities following breast cancer treatments: A systematic review

PURPOSE

To examine the risk factors for arm morbidity following breast cancer treatments, taking a broad view of all types of physical morbidity, including prolonged pain, lymphedema, decreased range of motion, and functional limitations.

METHODS

A systematic literature review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guidelines. Studies exploring the risk factors for prolonged arm morbidity following breast cancer surgery and treatments were included. The studies were assessed independently according to pre-eligibility criteria, following data extraction and methodological quality assessment.

RESULTS

1,242 articles were identified. After removing duplicates, the full texts of 1,153 articles were examined. Sixty-nine of these articles met the criteria and were included in the review. These 69 articles identified 29 risk factors for arm morbidity following treatments for breast cancer. The risk of bias was evaluated using NIH study quality assessment tools. The studies reviewed were published between 2001 and 2021 and included a total of 22,886 patients who were followed up for between three months and 10 years.

CONCLUSIONS

The main risk factors for long-term morbidity are removal of lymph nodes from the axilla, body mass index >30, having undergone a mastectomy, the stage of the disease, radiation therapy, chemotherapy, infection and trauma to the affected arm after surgery. An understanding of the risk factors for prolonged arm morbidity after surgery can help doctors and therapists in making personalized decisions about the need and timing of rehabilitation treatments.

A Review on the Management of Peripheral Neuropathic Pain Following Breast Cancer

Postmastectomy pain syndrome (PMPS) is a common and debilitating form of postsurgical pain with neuropathic characteristics, presenting as burning, stabbing, or pulling sensations after mastectomy, lumpectomy, or other breast procedures. With a prevalence of 31%, the risk factors for PMPS include younger age, psychosocial factors, radiotherapy, axillary lymph node dissection, and a history of chronic pain. This review evaluates the pharmacological and surgical options for managing PMPS. Pharmacological treatment options include antidepressants, gabapentinoids, levetiracetam, capsaicin, and topical lidocaine. Procedural and surgical options include fat grafting, nerve blocks, radiofrequency ablation, peripheral nerve surgery, serratus plane block, and botulinum toxin injections. Despite the variety of therapeutic options available for patients, further randomized trials are required to conclude whether these treatments reduce the intensity of neuropathic pain in patients with PMPS. In particular, comparative studies and the inclusion of patients across a range of pain intensities will be essential to developing a treatment algorithm for PMPS. In conclusion, current management for these patients should be tailored to their individual requirements.

Predictors of fatal and nonfatal overdose after prescription of opioids for chronic pain: a systematic review and meta-analysis of observational studies

BACKGROUND

Higher doses of opioids, mental health comorbidities, co-prescription of sedatives, lower socioeconomic status and a history of opioid overdose have been reported as risk factors for opioid overdose; however, the magnitude of these associations and their credibility are unclear. We sought to identify predictors of fatal and nonfatal overdose from prescription opioids.

METHODS

We systematically searched MEDLINE, Embase, CINAHL, PsycINFO and Web of Science up to Oct. 30, 2022, for observational studies that explored predictors of opioid overdose after their prescription for chronic pain. We performed random-effects meta-analyses for all predictors reported by 2 or more studies using odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Twenty-eight studies (23 963 716 patients) reported the association of 103 predictors with fatal or nonfatal opioid overdose. Moderate- to high-certainty evidence supported large relative associations with history of overdose (OR 5.85, 95% CI 3.78-9.04), higher opioid dose (OR 2.57, 95% CI 2.08-3.18 per 90-mg increment), 3 or more prescribers (OR 4.68, 95% CI 3.57-6.12), 4 or more dispensing pharmacies (OR 4.92, 95% CI 4.35-5.57), prescription of fentanyl (OR 2.80, 95% CI 2.30-3.41), current substance use disorder (OR 2.62, 95% CI 2.09-3.27), any mental health diagnosis (OR 2.12, 95% CI 1.73-2.61), depression (OR 2.22, 95% CI 1.57-3.14), bipolar disorder (OR 2.07, 95% CI 1.77-2.41) or pancreatitis (OR 2.00, 95% CI 1.52-2.64), with absolute risks among patients with the predictor ranging from 2-6 per 1000 for fatal overdose and 4-12 per 1000 for nonfatal overdose.

INTERPRETATION

We identified 10 predictors that were strongly associated with opioid overdose. Awareness of these predictors may facilitate shared decision-making regarding prescribing opioids for chronic pain and inform harm-reduction strategies SYSTEMATIC REVIEW REGISTRATION: Open Science Framework (https://osf.io/vznxj/).

Patient and procedure characteristics associated with postoperative pain after prophylactic versus therapeutic ambulatory bilateral breast surgery

BACKGROUND AND OBJECTIVES

We investigated whether age, body mass index (BMI), and tissue expander placement were related to postoperative opioid requirement for patients undergoing therapeutic versus prophylactic breast surgery.

METHODS

Postoperative opioid consumption was evaluated for patients who underwent bilateral mastectomy with immediate implant-based reconstruction at a freestanding ambulatory cancer surgery center between 2016 and 2021. Ordinal regression tested whether surgical indication was associated with increased postoperative opioid requirements after adjusting for age, BMI, and tissue expander placement.

RESULTS

Of 2447 patients, 6% underwent prophylactic surgeries. Therapeutic mastectomy patients had lower postoperative opioid requirement (OR = 0.67; 95% CI: 0.50-0.91; p = 0.030), but this was not significant after adjusting for covariates (OR = 0.75; 95% CI: 0.53-1.07; p = 0.2). Opioid use increased with higher BMI (OR = 1.06; 95% CI: 1.05-1.08; p < 0.001) and decreased with age (OR = 0.97; 95% CI: 0.96-0.98; p < 0.001) with therapeutic mastectomy patients being older (median 46 vs. 39). The subpectoral tissue expander group had nearly double the postoperative opioid requirement compared to prepectoral placement (OR = 1.86; 95% CI: 1.55-2.23; p < 0.001).

CONCLUSIONS

Increased postoperative opioid requirement in women undergoing prophylactic procedures is best explained by age. Mastectomy patients should be counseled similarly about postoperative pain irrespective of indication. A larger prophylactic mastectomy sample is required to provide more precise estimates.

The American Society of Breast Surgeons classification system for oncoplastic breast conserving surgery independently predicts the risk of delayed wound healing

INTRODUCTION

Oncoplastic breast conserving surgery (OBCS) aims to provide safe and satisfying surgery for breast cancer patients. The American Society of Breast Surgeons (ASBrS) classification system is based on volumetric displacement cut-offs (level I for <20% of breast volume; level II for 20-50%). It aims to facilitate communication among treating physicians and patients. Here, we investigate whether the extent of OBCS as classified by ASBrS independently predicts postoperative complications.

MATERIALS AND METHODS

This retrospective analysis of a prospectively maintained database included patients with stage I-III breast cancer who underwent OBCS between 03/2011 and 12/2020 at a Swiss university hospital. Outcomes included short-term (≤30 days) complications and chronic (>30 days) pain after surgery. Multivariate logistic regression models were used to identify independent predictors.

RESULTS

In total, 439 patients were included, 314 (71.5%) received ASBrS level I surgery, and 125 (28.5%) underwent ASBrS level II surgery. ASBrS level II was found to be an independent predictor of delayed wound healing (odds ratio [OR] 9.75, 95% confidence intervals (CI) 2.96-32.10). However, ASBrS level did not predict chronic postoperative pain (incidence rate ratio [IRR] 1.20, 95%CI 0.85-1.70), as opposed to age (IRR 1.19, 95%CI 1.11-1.27 per 5 years decrease), and weight disorders (underweight [BMI <18.5] vs. normal weight [BMI 18.5 < 25]: IRR 4.02, 95%CI 1.70-9.54; obese [BMI ≥30] vs. normal weight: IRR 2.07, 95%CI 1.37-3.13).

CONCLUSION

ASBrS level II surgery predicted delayed wound healing, warranting close clinical follow-up and prompt treatment to avoid delays in adjuvant therapy.

The Acute Perioperative Pain Service: Impact, Organization, and Future Directions

PURPOSE OF REVIEW

The Acute Perioperative Pain Service has been established as a relatively new but important concept and service in clinical patient care. Many surgical institutions have dedicated inpatient acute pain services with variable compositions. This review aims to investigate the purpose, clinical and economic implications, and future direction of the Acute Perioperative Pain Service (APPS).

RECENT FINDINGS

There is growing evidence of the multiple benefits of a dedicated APPS, especially pertaining to patients at higher risk of poorly controlled postoperative pain. Healthcare providers furthermore realize the importance of the perioperative pain management continuity of care, consisting of preoperative pain evaluations and post-discharge follow-up in an outpatient pain management setting, in coordination with the primary teams. The Transitional Pain Service (TPS) has emerged as the next step in this evolution and has been successfully implemented at various medical centers. With the growing number of surgical procedures and the increasing complexity of the patient population, effective management of acute postoperative pain continues to be challenging, despite ongoing advances in clinical care, analgesic modalities, and research. The APPS is becoming the clinical standard of care for managing postoperative pain, and its role continues to expand worldwide.

Predicting chronic postsurgical pain: current evidence and a novel program to develop predictive biomarker signatures

ABSTRACT

Chronic pain affects more than 50 million Americans. Treatments remain inadequate, in large part, because the pathophysiological mechanisms underlying the development of chronic pain remain poorly understood. Pain biomarkers could potentially identify and measure biological pathways and phenotypical expressions that are altered by pain, provide insight into biological treatment targets, and help identify at-risk patients who might benefit from early intervention. Biomarkers are used to diagnose, track, and treat other diseases, but no validated clinical biomarkers exist yet for chronic pain. To address this problem, the National Institutes of Health Common Fund launched the Acute to Chronic Pain Signatures (A2CPS) program to evaluate candidate biomarkers, develop them into biosignatures, and discover novel biomarkers for chronification of pain after surgery. This article discusses candidate biomarkers identified by A2CPS for evaluation, including genomic, proteomic, metabolomic, lipidomic, neuroimaging, psychophysical, psychological, and behavioral measures. Acute to Chronic Pain Signatures will provide the most comprehensive investigation of biomarkers for the transition to chronic postsurgical pain undertaken to date. Data and analytic resources generatedby A2CPS will be shared with the scientific community in hopes that other investigators will extract valuable insights beyond A2CPS's initial findings. This article will review the identified biomarkers and rationale for including them, the current state of the science on biomarkers of the transition from acute to chronic pain, gaps in the literature, and how A2CPS will address these gaps.

The incidence, impact, and risk factors for moderate to severe persistent pain after breast cancer surgery: a prospective cohort study

BACKGROUND

Few Australasian studies have evaluated persistent pain after breast cancer surgery.

OBJECTIVE

To evaluate the incidence, impact, and risk factors of moderate to severe persistent pain after breast cancer surgery in a New Zealand cohort.

DESIGN

Prospective cohort study.

METHODS

Consented patients were reviewed at 3 timepoints (preoperative, 2 weeks and 6 months postoperative). Pain incidence and interference, psychological distress and upper limb disability were assessed perioperatively. Clinical, demographic, psychological, cancer treatment-related variables, quantitative sensory testing, and patient genotype (COMT, OPRM1, GCH1, ESR1, and KCNJ6) were assessed as risk factors using multiple logistic regression.

RESULTS

Of the 173 patients recruited, 140 completed the 6-month follow-up. Overall, 15.0% (n = 21, 95% CI: 9.5%-22.0%) of patients reported moderate to severe persistent pain after breast cancer surgery with 42.9% (n = 9, 95% CI: 21.9%-66.0%) reporting likely neuropathic pain. Pain interference, upper limb dysfunction and psychological distress were significantly higher in patients with moderate to severe pain (P < .004). Moderate to severe preoperative pain (OR= 3.60, 95% CI: 1.13-11.44, P = .03), COMT rs6269 GA genotype (OR = 5.03, 95% CI: 1.49-17.04, P = .009) and psychological distress at postoperative day 14 (OR= 1.08, 95% CI: 1.02-1.16, P = .02) were identified as risk factors. Total intravenous anesthesia (OR= 0.31, 95% CI: 0.10 - 0.99, P = .048) was identified as protective.

CONCLUSION

The incidence of moderate to severe persistent pain after breast cancer surgery is high with associated pain interference, physical disability, and psychological distress. Important modifiable risk factors were identified to reduce this important condition.

Translational research updates in female health anesthesiology: a narrative review

Background and Objective

Females represent 49.6% of the global population and constitute a significant proportion of surgical patients and hospital admissions. Little is known about the bi-directional effects of sex and anesthetics or the impact of anesthetic interventions on long-term female health outcomes. Sex differences in pain pathways can influence pain experience and treatment effectiveness. The impact of anesthetic management on the recurrence of breast cancer is poorly understood, as are the long-term consequences of cardiovascular disease and safe and effective treatments in pregnancy. This review aims to outline recent advances in translational science in female health anesthesiology research and highlight critical research opportunities in pain, cancer outcomes, and cardiovascular disorders.

Methods

We searched PubMed and summarized relevant articles published in English between December 2021 and June 2022.

Key Content and Findings

Studies reveal sex differences in pain pathways and highlight the importance of sex as a biological variable in experimental designs and translational medicine. Sex differences have also been observed in side effects attributed to opioid analgesics. We summarize some of the neural circuits that might underlie these differences. In the perioperative setting, specific anesthetics are implicated in metastatic seeding potential and acute and chronic pain outcomes, suggesting the importance of anesthetic selection in comprehensive care during oncologic surgery. In the peridelivery setting, preeclampsia, a cardiovascular disorder of pregnancy, affects maternal outcomes; however, biomarkers can risk-stratify females at risk for preeclampsia and hold promise for identifying the risk of adverse neurological and other health outcomes.

Conclusions

Research that builds diagnostic and predictive tools in pain and cardiovascular disease will help anesthesiologists minimize sex-related risks and side effects associated with anesthetics and peri-hospital treatments. Sex-specific anesthesia care will improve outcomes, as will the provision of practical information to patients and clinicians about the effectiveness of therapies and behavioral interventions. However, more research studies and specific analytic plans are needed to continue addressing sex-based outcomes in anesthesiology.

Emotional Processing, Coping, and Cancer-Related Sickness Symptoms in Breast Cancer Survivors: Cross- Sectional Secondary Analysis of the REPAT Study

Purpose

The study aims to provide a better understanding of the relationship between emotional processing, coping, and cancer-related sickness symptoms.

Methods

The study used a cross-sectional, secondary analysis of data from 179 Israeli Jewish women who were breast cancer survivors (BCS) 3 to 18 months after completing primary treatment and who participated in a larger randomized controlled trial (REPAT study). Data were collected at baseline. Participants completed questionnaires measuring emotion acceptance, situational approach, avoidance coping, and cancer-related sickness symptoms (depression, fatigue, and pain) and a performance measure of emotional awareness. Hierarchical linear regressions were performed, controlling for background variables.

Results

Participants experienced significant clinical depression (51.7%), cancer-related fatigue (CRF, 78.8%), pain interference (78%), and pain intensity (66%) levels. There were strong correlations between cancer-related symptoms. After controlling for confounders, emotional processing (acceptance) was negatively associated with depression, and avoidance coping was positively associated with depression, CRF, and pain interference (i.e., higher use of avoidance related to higher cancer-related symptoms; higher acceptance was associated with lower depression). Emotional awareness and coping by approaching emotions were not related to cancer-related symptoms.

Conclusions

The BCS posttreatment period presents the challenge of dealing with elevated cancer-related symptoms. Regardless, BCS who used high emotional processing levels-especially acceptance of emotion and lower reliance on avoidance to cope-experienced fewer cancer-related symptoms.

Implications for Cancer Survivors

Professionals should recognize the potential role of emotional processing and avoidant coping relative to cancer-related symptoms and recognize their patterns in posttreatment patients.

Identifying risk factors for chronic postsurgical pain and preventive measures: a comprehensive update

INTRODUCTION

Chronic postsurgical pain (CPSP) is a prevalent condition that can diminish health-related quality of life, cause functional deficits, and lead to patient distress. Rates of CPSP are higher for certain types of surgeries than others (thoracic, breast, or lower extremity amputations) but can occur after even uncomplicated minimally invasive procedures. CPSP has multiple mechanisms, but always starts as acute postsurgical pain, which involves inflammatory processes and may encompass direct or indirect neural injury. Risk factors for CPSP are largely known but many, such as female sex, younger age, or type of surgery, are not modifiable. The best strategy against CPSP is to quickly and effectively treat acute postoperative pain using a multimodal analgesic regimen that is safe, effective, and spares opioids.

AREAS COVERED

This is a narrative review of the literature.

EXPERT OPINION

Every surgical patient is at some risk for CPSP. Control of acute postoperative pain appears to be the most effective approach, but principles of good opioid stewardship should apply. The role of regional anesthetics as analgesics is gaining interest and may be appropriate for certain patients. Finally, patients should be better informed about their relative risk for CPSP.

Prevalence of unpaid caregiving, pain, and depression in older seriously ill patients undergoing elective surgery

INTRODUCTION

Serious illness is a life-limiting condition negatively impacting daily function, quality of life, or excessively straining caregivers. Over 1 million older seriously ill adults undergo major surgery annually, and national guidelines recommend that palliative care be available to all seriously ill patients. However, the palliative care needs of elective surgical patients are incompletely described. Understanding baseline caregiving needs and symptom burden among seriously ill older surgical patients could inform interventions to improve outcomes.

METHODS

Using Health and Retirement Study data (2008-2018) linked to Medicare claims, we identified patients ≥66 years who met an established serious illness definition from administrative data and underwent major elective surgery using Agency for Healthcare Research and Quality (AHRQ) criteria. Descriptive analyses were performed for preoperative patient characteristics, including: unpaid caregiving (no or yes); pain (none/mild or moderate/severe); and depression (no, CES-D < 3, or yes, CES-D ≥ 3). Multivariable regression was performed to examine the association between unpaid caregiving, pain, depression, and in-hospital outcomes, including hospital days (days admitted between discharge date and one-year post-discharge), in-hospital complications (no or yes), and discharge destination (home or non-home).

RESULTS

Of the 1343 patients, 55.0% were female and 81.6% were non-Hispanic White. Mean age was 78.0 (SD 6.8); 86.9% had ≥2 comorbidities. Before admission, 27.3% of patients received unpaid caregiving. Pre-admission pain and depression were 42.6% and 32.8%, respectively. Baseline depression was significantly associated with non-home discharge (OR 1.6, 95% CI 1.2-2.1, p = 0.003), while baseline pain and unpaid caregiving needs were not associated with in-hospital or post-acute outcomes in multivariable analysis.

CONCLUSIONS

Prior to elective surgery, older adults with serious illnesses have high unpaid caregiving needs and a prevalence of pain and depression. Baseline depression alone was associated with discharge destinations. These findings highlight opportunities for targeted palliative care interventions throughout the surgical encounter.

Immediate impact of Mindfulness-Based Cognitive Therapy (MBCT) among women with breast cancer: a systematic review and meta-analysis

BACKGROUND

Mindfulness-based cognitive therapy (MBCT) may have positive physiological and psychological benefits for breast cancer survivors. However, few studies involved a combination of the relevant literatures to confirm the effects.

METHODS

Our study included randomized controlled trials (RCTs) and non-RCTs comparing interventions of MBCT and control protocols for alleviation of symptoms among breast cancer survivors. We calculated pooled mean differences (MDs), standardized mean differences (SMDs), and 95% confidence intervals (CIs) by using random effects models to estimate summary effect sizes.

RESULTS

Thirteen trials with 20-245 participants were considered in our studies; for the meta-analysis, 11 of these studies were eligible for assessment. The pooled meta-analysis results revealed that at the end of the MBCT intervention, participants' anxiety (SMD, - 0.70; 95% CI, - 1.26 to - 0.13; I2 = 69%), pain (SMD, - 0.64; 95% CI, - 0.92 to - 0.37; I2 = 0%), and depression (SMD, - 0.65; 95% CI, - 1.14 to - 0.17; I2 = 75%) levels significantly decreased, and their mindfulness (MD, 8.83; 95% CI, 3.88 to 13.78; I2 = 68%) levels significantly increased.

CONCLUSION

The MBCT may be associated with improved pain, anxiety, depression, and mindfulness. However, the quantitative analysis pointed to an inconclusive result due to moderate to high levels of heterogeneity among indicator of anxiety, depression, and mindfulness. Future work requires more studies to better elucidate the clinical significance of this possible association. The results suggest that MBCT is highly beneficial as an intervention for patients who have received treatment for breast cancer.

Sex and age differences in chronic postoperative pain among patients undergoing thoracic surgery: a retrospective cohort study

Background

The effect of sex and age on chronic post-thoracic surgical pain (CPTP) at rest and with activity remains unclear. The main purpose of this study was to investigate the relationship between the incidence of chronic postoperative pain (at rest and with activity) and sex/age differences.

Methods

This was a single-center retrospective study that included adult patients who had undergone elective thoracic surgery. Patients were divided into two groups based on sex. Demographic and perioperative data were collected, including age, sex, education level, Body Mass Index (BMI), American Society of Anesthesiologists (ASA) physical status, and medical history (hypertension, diabetes mellitus). Chronic postoperative pain data were collected by telephone follow-up.

Results

Among the 3,159 patients enrolled, 1,762 were male, and 1,397 were female. After creating a matched-pairs cohort, 1,856 patients were analyzed. The incidence of CPTP at rest was 14.9% among males and 17.8% among females (p = 0.090). The incidence of CPTP with activity was 28.4% among males and 35.0% among females (p = 0.002). We analyzed three different models after propensity matching to validate the stability of the prediction model between sex and CPTP, and female sex was a significant predictor of CPTP with activity 3 months after surgery. Further analysis showed that females in the 45-55-year-old age group were more prone to develop CPTP.

Conclusion

Females have a higher incidence of chronic postoperative pain with activity after thoracic surgery. Females in the 45-55-year-old age group are more prone to develop CPTP than females in other age groups.

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.

Postoperative effect of sufentanil preemptive analgesia combined with psychological intervention on breast cancer patients

OBJECTIVES

To explore the postoperative effects of sufentanil preemptive analgesia combined with psychological intervention on breast cancer patients undergoing radical surgery.

METHODS

112 female breast cancer patients aged 18-80 years old who underwent radical surgery by the same surgeon were randomly divided into 4 groups, and there were 28 patients in each group. Patients in group A were given 10 µg sufentanil preemptive analgesia combined with perioperative psychological support therapy (PPST), group B had only 10 µg sufentanil preemptive analgesia, group C had only PPST, and group D were under general anesthesia with conventional intubation. Visual analogue scoring (VAS) was used for analgesic evaluation at 2, 12 and 24 h after surgery and compared among the four groups by ANOVA method.

RESULTS

The awakening time of patients in group A or B was significantly shorter than that in group C or D, and the awakening time in group C was significantly shorter than that in group D. Moreover, patients in group A had the shortest extubation time, while the group D had the longest extubation time. The VAS scores at different time points showed significant difference, and the VAS scores at 12 and 24 h were significantly lower than those at 2 h (P < 0.05). The VAS scores and the changing trend of VAS scores were varied among the four groups (P < 0.05). In addition, we also found that patients in group A had the longest time to use the first pain medication after surgery, while patients in group D had the shortest time. But the adverse reactions among the four groups showed no difference.

CONCLUSIONS

Sufentanil preemptive analgesia combined with psychological intervention can effectively relieve the postoperative pain of breast cancer patients.

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.

Predictors of Recovery Following Lumbar Microdiscectomy for Sciatica: A Systematic Review and Meta-Analysis of Observational Studies

Chronic post-surgical pain is reported by up to 40% of patients after lumbar microdiscectomy for sciatica, a complaint associated with disability and loss of productivity. We conducted a systematic review of observational studies to explore factors associated with persistent leg pain and impairments after microdiscectomy for sciatica. We searched eligible studies in MEDLINE, Embase, and CINAHL that explored, in an adjusted model, predictors of persistent leg pain, physical impairment, or failure to return to work after microdiscectomy for sciatica. When possible, we pooled estimates of association using random-effects models using the Grading of Recommendations Assessment, Development, and Evaluation approach. Moderate-certainty evidence showed that the female sex probably has a small association with persistent post-surgical leg pain (odds ratio (OR) = 1.15, 95% confidence interval (CI) = 0.63 to 2.08; absolute risk increase (ARI) = 1.8%, 95% CI = -4.7% to 11.3%), large association with failure to return to work (OR = 2.79, 95% CI = 1.27 to 6.17; ARI = 10.6%, 95% CI = 1.8% to 25.2%), and older age is probably associated with greater postoperative disability (β = 1.47 points on the 100-point Oswestry Disability Index for every 10-year increase from age (>/=18 years), 95% CI = -4.14 to 7.28). Among factors that were not possible to pool, two factors showed promise for future study, namely, legal representation and preoperative opioid use, which showed large associations with worse outcomes after surgery. The moderate-certainty evidence showed female sex is probably associated with persistent leg pain and failure to return to work and that older age is probably associated with greater post-surgical impairment after a microdiscectomy. Future research should explore the association between legal representation and preoperative opioid use with persistent pain and impairment after microdiscectomy for sciatica.

Rat model of attention-deficit hyperactivity disorder exhibits delayed recovery from acute incisional pain due to impaired descending noradrenergic inhibition

Chronic pain and attention-deficit hyperactivity disorder (ADHD) frequently coexist. However, the common pathology is still unclear. Attenuated noradrenergic endogenous analgesia can produce acute pain chronification, and dysfunction of noradrenergic systems in the nervous system is relevant to ADHD symptoms. Noxious stimuli-induced analgesia (NSIA) is measured to estimate noradrenergic endogenous analgesia in spontaneously hypertensive rats (SHR) as an ADHD model and control. Recovery of pain-related behaviors after paw incision was assessed. Contributions of noradrenergic systems were examined by in vivo microdialysis and immunohistochemistry. The SHR showed attenuated NSIA and needed a more extended period for recovery from acute pain. These results suggest ADHD patients exhibit acute pain chronification due to pre-existing attenuated noradrenergic endogenous analgesia. Immunohistochemistry suggests abnormal noradrenaline turnover and downregulation of the target receptor (alpha2a adrenoceptor). Standard ADHD treatment with atomoxetine restored NSIA and shortened the duration of hypersensitivity after the surgery in the SHR. NSIA protocol activated the locus coeruleus, the origin of spinal noradrenaline, of both strains, but only the control exhibited an increase in spinal noradrenaline. This result suggests dysfunction in the noradrenaline-releasing process and can be recognized as a novel mechanism of attenuation of noradrenergic endogenous analgesia.

Neurotrophin-3 (NT-3) as a Potential Biomarker of the Peripheral Nervous System Damage Following Breast Cancer Treatment

Damage to the peripheral nervous system (PNS) is a common complication of breast cancer (BC) treatment, with 60 to 80% of breast cancer survivors experiencing symptoms of PNS damage. In the current study, the levels of brain-derived neurotrophic factor (BDNF), galectin-3 (Gal-3), and neurotrophin-3 (NT-3) were measured in the blood serum of BC patients by ELISA as potential biomarkers that might indicate the PNS damage. Sixty-seven patients were enrolled in this multi-center trial and compared to the aged-matched healthy female volunteers (control group) (n = 25). Intergroup comparison of biomarker levels (i.e., Gal-3 and BDNF) did not show significant differences in any of the studied subgroups. However, intriguingly, NT-3 levels were significantly higher in BC patients as compared to healthy volunteers, constituting 14.85 [10.3; 18.0] and 5.74 [4.56; 13.7] pg/mL, respectively (p < 0.001). In conclusion, NT-3 might be employed as a potential biomarker in BC patients with clinical manifestations of PNS damage. However, further studies to validate its correlation to the degree of peripheral nervous system lesions are of high value.

Unresolved early post-operative pain trajectory predicts moderate-to-severe persistent pain after breast cancer surgery-An observational cohort study

BACKGROUND

Modelling acute post-operative pain trajectories may improve the prediction of persistent pain after breast cancer surgery (PPBCS). This study aimed to investigate the predictive accuracy of early post-operative pain (EPOP) trajectories in the development of PPBCS.

MATERIALS & METHODS

This observational study was conducted in a French Comprehensive Cancer Centre and included patients who underwent breast cancer surgery from December 2017 to November 2018. Perioperative and follow-up data were obtained from medical records, and anaesthesia and perioperative charts. EPOP was defined as pain intensity during the first 24 h after surgery, and modelled by a pain trajectory. K-means clustering method was used to identify patient subgroups with similar EPOP trajectories. The prevalence of moderate-to-severe PPBCS (numeric rating scale ≥4) was evaluated until 24 months after surgery.

RESULTS

A total of 608 patients were included in the study, of which 18% (n = 108) and 9% (n = 52) reported mild and moderate-to-severe PPBCS, respectively. Based on EPOP trajectories, we were able to identify a low (64%, n = 388), resolved (30%, n = 182), and unresolved (6%, n = 38) pain group. Multivariate analysis identified younger age, axillary lymph node dissection, and unresolved EPOP trajectory as independent risk factors for moderate-to-severe PPBCS development. When compared to patients reporting mild PPBCS, moderate-to-severe PPBCS patients experienced significantly more neuropathic pain features, pain-related interference, and delayed opioid cessation.

CONCLUSION

EPOP trajectories can distinguish between resolved and unresolved acute pain after breast cancer surgery, allowing early identification of patients at risk to develop significant PPBCS.

The postoperative analgesic efficacy of different regional anesthesia techniques in breast cancer surgery: A network meta-analysis

Background

Regional anesthesia have been successfully performed for pain management in breast cancer surgery, but it is unclear which is the best regional anesthesia technique. The aim of the present network meta-analysis was to assess the analgesic efficacy and disadvantages of regional anesthesia techniques.

Methods

Multiple databases were searched for randomized controlled trials (RCTs). The association between regional anesthesia and analgesic efficacy was evaluated by Bayesian network meta-analysis.

Results

We included 100 RCTs and 6639 patients in this study. The network meta-analysis showed that paravertebral nerve block, pectoral nerve-2 block, serratus anterior plane block, erector spinae plane block, rhomboid intercostal block, and local anesthetic infusion were associated with significantly decreased postoperative pain scores, morphine consumption and incidence of postoperative nausea and vomiting compared with no block. Regarding the incidence of chronic pain, no significance was detected between the different regional anesthesia techniques. In the cumulative ranking curve analysis, the rank of the rhomboid intercostal block was the for postoperative care unit pain scores, postoperative 24-hour morphine consumption, and incidence of postoperative nausea and vomiting.

Conclusion

Regional anesthesia techniques including, paravertebral nerve block, pectoral nerve-2 block, serratus anterior plane block, erector spinae plane block, rhomboid intercostal block, and local anesthetic infusion, can effectively alleviate postoperative acute analgesia and reduce postoperative morphine consumption, but cannot reduce chronic pain after breast surgery. The rhomboid intercostal block might be the optimal technique for postoperative analgesia in breast cancer surgery, but the strength of the evidence was very low.

Systematic review registration

https://www.crd.york.ac.uk/prospero/(PROSPERO), identifier CRD 42020220763.

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).

Predictors of persistent post-surgical pain intensity and interference at 1 year after breast cancer surgery: assessing central sensitization, central sensitivity symptoms, and psychological factors

BACKGROUND

Persistent post-surgical pain (PPSP) is associated with upper limb dysfunction and decreased quality of life and causes long-term suffering for breast cancer survivors after surgery. However, the predictors of PPSP remain unclear. The purpose of this study was to examine predictors of PPSP intensity and interference at 1 year postoperatively, focusing on treatment-related factors, pre- and postoperative central sensitization (CS), CS-related symptoms (e.g., muscle stiffness, fatigue, sleep disturbances), and psychological factors.

METHODS

Eighty-eight women with planned unilateral breast cancer surgery were included in this longitudinal study. CS, CS-related symptoms, and psychological factors were assessed preoperatively, 1 month postoperatively, and 1 year postoperatively. Analysis of covariance was used to compare the groups with and without PPSP, accounting for treatment-related factors. Multiple regression analysis was performed to identify predictors of PPSP intensity and interference at 1 year postoperatively.

RESULTS

Even after adjusting for covariates, preoperative and 1-month postoperative Central Sensitization Inventory scores in the PPSP group were significantly higher than scores in the group without PPSP. Multiple regression analysis showed that axillary lymph node dissection (ALND) and 1-month postoperative CS-related symptoms were independent predictors of PPSP intensity and interference at 1 year postoperatively (p < 0.01).

CONCLUSION

We found that ALND and 1-month postoperative CS-related symptoms were predictors of PPSP intensity and interference at 1 year postoperatively.

Association of OPRM1, MIR23B, and MIR107 genetic variability with acute pain, chronic pain and adverse effects after postoperative tramadol and paracetamol treatment in breast cancer

BACKGROUND

Tramadol is an opioid analgesic often used for pain management after breast cancer surgery. Its analgesic activity is due to the activation of the μ-opioid receptor, encoded by the OPRM1 gene. This study investigated the association of genetic variability in OPRM1 and its regulatory miRNA genes with outcomes of tramadol/paracetamol treatment after breast cancer surgery with axillary lymphadenectomy.

PATIENTS AND METHODS

The study included 113 breast cancer patients after breast cancer surgery with axillary lymphadenectomy treated with either 75/650 mg or 37.5/325 mg of tramadol with paracetamol for pain relief within the randomized clinical trial KCT 04/2015-DORETAonko/si at the Institute of Oncology Ljubljana. All patients were genotyped for OPRM1 rs1799971 and rs677830, MIR23B rs1011784, and MIR107 rs2296616 using competitive allele-specific PCR. The association of genetic factors with acute and chronic pain as well as adverse effects of tramadol treatment was evaluated using logistic regression, Fisher's exact test, and Mann-Whitney test.

RESULTS

The investigated OPRM1 related polymorphisms were not associated with acute pain assessed with the VAS scale within four weeks after surgery (all P > 0.05). Carriers of at least one polymorphic OPRM1 rs1799971 allele had a higher risk of constipation in the first four weeks after surgery compared to non-carriers (OR = 4.5, 95% CI = 1.6-12.64, P = 0.004). Carriers of at least one polymorphic OPRM1 rs677830 allele had a higher risk of constipation after third week of tramadol treatment (OR = 3.11, 95% CI = 1.08-8.89, P = 0.035). Furthermore, carriers of two polymorphic MIR23B rs1011784 alleles had a higher risk of nausea after 28 days of tramadol treatment (OR = 7.35, 95% CI = 1.27-42.6, P = 0.026), while heterozygotes for MIR107 rs2296616 allele had a lower risk of nausea after 21 days of tramadol treatment (OR = 0.21, 95% CI = 0.05-0.87, P = 0.031). In carriers of two polymorphic MIR107 rs2296616 alleles, chronic pain was significantly more common than in carriers of two wild-type alleles (P = 0.004). Carriers of at least one polymorphic MIR23B rs1011784 allele experienced more neuropathic pain after adjustment for tramadol dose (OR = 2.85, 95% CI = 1.07-7.59, P = 0.036), while carriers of at least one polymorphic OPRM1 rs677830 allele experienced less neuropathic pain compared to carriers of two wild-type alleles (OR = 0.38, 95% CI = 0.15-0.99, P = 0.047).

CONCLUSIONS

Genetic variability of OPRM1 and genes coding for miRNAs that could affect OPRM1 expression may be associated with adverse effects of tramadol/paracetamol treatment as well as with chronic and neuropathic pain after breast cancer surgery with axillary lymphadenectomy.

OptiBra study, a randomized controlled trial on optimal postoperative bra support after breast cancer surgery

AIM

This randomized controlled trial aimed to compare two different postoperative bras after breast cancer surgery and evaluate their impact on primary outcome pain.

METHOD

The study included 201 patients scheduled for primary surgery (breast conserving surgery with sentinel node biopsy or axillary clearance, mastectomy, or mastectomy with primary implant reconstruction with sentinel node biopsy or axillary clearance). Participants were randomized to either a soft bra or stable bra with compression. The patients were recommended to use the bra 24 h/day for 3 weeks, record daily pain (NRS), analgesic use and hours of bra use.

RESULTS

Follow up was completed by 184 patients. No significant differences between the arms were found considering pain score over time, neither day 1-14, nor after 3 weeks. Sixty-eight percent of all patients, regardless of randomization, reported pain during the first 14 days. After 3 weeks 46% still reported pain in the operated breast. Among these, patients randomized to the stable bra with compression reported significantly lower pain score than those randomized to the soft bra. Patients who used the stable bra with compression reported significantly higher levels of comfort, sense of security during activity, less difficulty moving the arm, as well as support and stability for the operated breast compared to those using the soft bra.

CONCLUSION

Using a stable bra with compression is the optimal evidence-based choice after breast cancer surgery to reduce remaining pain 3 weeks after surgery, increasing mobility, comfort, and sense of security.

TRIAL REGISTRATION NUMBER

NCT04059835 at www.

CLINICALTRIALS

gov.

Efficacy of proprioceptive neuromuscular facilitation in improving shoulder biomechanical parameters, functionality, and pain after axillary lymph node dissection for breast cancer: A randomized controlled study

PURPOSE

Axillary lymph node dissection and radiotherapy have been associated with pain, physical symptoms, and decreased functional abilities in the upper extremity. This study aimed to evaluate the potential effects of the proprioceptive neuromuscular facilitation (PNF) technique on muscle strength, pain and functionality in this patient group in comparison with progressive resistance training (PRT).

METHODS

The study was conducted with a randomized clinical trial design. Sixty-six women were included in the study and randomly divided into three groups: the PNF group (n = 22), the PRT group (n = 22), and the control group (n = 22). The participants were evaluated at the baseline and after eight weeks of treatment. Outcome measures were determined as pain (the Visual Analog Scale), upper extremity strength (isokinetic dynamometer), functionality (the Disabilities of the Arm, Shoulder and Hand questionnaire), and perception of change (the Global Rating of Change Scale).

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT05288036.

RESULTS

The results showed statistically significant changes in both treatment groups in terms of shoulder flexors/extensors, abductor/adductors, internal/external rotators strength/power/endurance measurement, pain, and functionality (p < 0.05). Concerning functionality and perception of change, the PNF group had a statistically significantly higher improvement compared to the remaining two groups (p < 0.05).

CONCLUSION

PNF is an effective technique in increasing upper extremity muscle strength, reducing pain during rest and activity, and improving functionality in patients receiving breast cancer treatment.

Feasibility and pilot testing of a personalized eHealth intervention for pain science education and self-management for breast cancer survivors with persistent pain: a mixed-method study

PURPOSE

Here, we describe the development and pilot study of a personalized eHealth intervention containing a pain science education program and self-management support strategies regarding pain and pain-related functioning in female survivors of breast cancer. First, we aimed to evaluate the eHealth intervention's acceptability, comprehensibility, and satisfaction; second, we aimed to assess its preliminary efficacy.

METHODS

A mixed-method study design was used. Breast cancer survivors with persistent pain were recruited. After 6 weeks of engagement with the eHealth intervention, acceptability, comprehensibility, and satisfaction were measured quantitatively with a self-constructed questionnaire and described qualitatively using focus groups. A joint display was used to present the meta-interferences between data. Efficacy was assessed via mixed effects models with repeated measures (outcomes assessed at baseline, 6 weeks, and 12 weeks).

RESULTS

Twenty-nine women with persistent pain after breast cancer surgery participated. Overall, the eHealth program was well received and experienced as easy to use and helpful. The eHealth intervention seems useful as an adjunct to comprehensive cancer aftercare. Efficacy estimates suggested a significant improvement in pain-related functioning, physical functioning, and quality of life.

CONCLUSION

A personalized eHealth intervention appears valuable for persistent pain management after breast cancer surgery. A large controlled clinical trial to determine effectiveness, and a full process evaluation, seems warranted.

Acute and subacute postsurgical pain in women with breast cancer: incidence and associations with biopsychosocial predictors-a secondary analysis of a randomized controlled trial

Introduction

Women who undergo breast cancer surgery risk suffering from postsurgical pain long after their surgery. Still, research on postsurgical pain in the subacute phase has been neglected.

Objective

This study aims to investigate the incidence, intensity, unpleasantness, and presurgical predictors of acute and subacute postsurgical pain after breast cancer surgery.

Methods

The study used an observational design through secondary analyses of the control group in a randomized controlled trial. Data from 102 women undergoing breast cancer surgery were included. Levels of acute and subacute pain intensity and unpleasantness were measured using 100 mm Visual Analogue Scales on the day of surgery and 4 weeks postsurgery. Linear regression analyses were performed to identify presurgical biopsychosocial predictors of acute and subacute postsurgical pain.

Results

Average levels of postsurgical pain intensity and unpleasantness were as follows: 22.7 mm for acute pain intensity, 19.0 mm for acute pain unpleasantness, 10.3 mm for subacute pain intensity, and 11.7 mm for subacute pain unpleasantness. Pain expectancy predicted acute pain intensity (R² = 0.04, p = 0.047) and acute unpleasantness (R² = 0.06, p = 0.02). Perceived social support inversely predicted acute pain unpleasantness (R² = 0.04, p = 0.014).

Conclusion

Mild and moderate acute pain intensity and unpleasantness are common after breast cancer surgery, whereas levels of subacute pain intensity and unpleasantness are low. Pain expectancy predicts acute postsurgical pain intensity and unpleasantness, whereas expected social support inversely predicts acute postsurgical pain unpleasantness.

Sexuality after breast cancer, how to provide a global and contemporary approach

Patients' sexuality is one of the major and most neglected impact of breast cancer (BC) and its treatment. Even though research is ongoing on the subject, sexuality issues are rarely taken into account and efficiently dealt with in clinical practice. The objective is to review the impact of BC and its treatment on modern women sexuality. In the literature, a heterogeneous level of advancement is notable in the different publishing countries depending on the cultural background; some countries simply do not publish on the matter, others mainly discuss the male partners and practicians experience, and lastly, the most progressive countries have moved up to studying niches of patients such as sexual and gender minorities. A multidisciplinary approach, including pharmacologic and nonpharmacologic management, appears most efficient. There is a need for greater inclusion of partners and for providing a specific training to first-line health care providers. This review provides a general contemporary worldwide overview of the state of the art in sexuality issues in BC patients and survivors.

Prediction models for chronic postsurgical pain in patients with breast cancer based on machine learning approaches

Purpose

This study aimed to develop prediction models for chronic postsurgical pain (CPSP) after breast cancer surgery using machine learning approaches and evaluate their performance.

Methods

The study was a secondary analysis based on a high-quality dataset from a randomized controlled trial (NCT00418457), including patients with primary breast cancer undergoing mastectomy. The primary outcome was CPSP at 12 months after surgery, defined as modified Brief Pain Inventory > 0. The dataset was randomly split into a training dataset (90%) and a testing dataset (10%). Variables were selected using recursive feature elimination combined with clinical experience, and potential predictors were then incorporated into three machine learning models, including random forest, gradient boosting decision tree and extreme gradient boosting models for outcome prediction, as well as logistic regression. The performances of these four models were tested and compared.

Results

1152 patients were finally included, of which 22.1% developed CPSP at 12 months after breast cancer surgery. The 6 leading predictors were higher numerical rating scale within 2 days after surgery, post-menopausal status, urban medical insurance, history of at least one operation, under fentanyl with sevoflurane general anesthesia, and received axillary lymph node dissection. Compared with the multivariable logistic regression model, machine learning models showed better specificity, positive likelihood ratio and positive predictive value, helping to identify high-risk patients more accurately and create opportunities for early clinical intervention.

Conclusions

Our study developed prediction models for CPSP after breast cancer surgery based on machine learning approaches, which may help to identify high-risk patients and improve patients' management after breast cancer.

Single-Dose of Postoperative Ketamine for Postoperative Pain After Mastectomy: A Pilot Randomized Controlled Trial

Background and Objectives

Perioperative ketamine has been shown to reduce opioid consumption and pain after surgery. Ketamine is most often given as an infusion, but an alternative is single-dose ketamine. Single-dose ketamine at up to 1 mg/kg has been shown to reduce symptoms of depression, and a wide range of dosages has been used for pain in the emergency department. However, limited data exists on the tolerability and efficacy of a single-dose of ketamine at 0.6 mg/kg for pain when administered immediately after surgery. We conducted a pilot study of single-dose ketamine in patients undergoing mastectomy with reconstruction, hypothesizing that a single-dose of ketamine is well tolerated and can relieve postoperative pain and improve mood and recovery.

Methods

This is a randomized, single-blind, placebo-controlled, two-arm parallel, single-center study. Thirty adult women undergoing mastectomy with reconstruction for oncologic indication received a single-dose of ketamine (0.6mg/kg) or placebo after surgery in the post-anesthesia care unit (PACU). Patients were followed through postoperative day (POD) 7. The primary outcome was postoperative pain measured by the Brief Pain Inventory (BPI) pain subscale on POD 1 and 2. Secondary outcomes include effects on opioid use, PROMIS fatigue and sleep, mood, Quality of Recovery-15, and the Breast Cancer Pain Questionnaire.

Results

Side effects were minor and not significantly different in frequency between groups. The ketamine group reported lower scores on the BPI pain severity subscale, especially at POD 7; however, the difference was not statistically significant. There were no statistically significant differences between ketamine and placebo groups for the secondary outcomes.

Conclusion

A single-dose of ketamine at 0.6mg/kg administered postoperatively in the PACU is well tolerated in women undergoing mastectomy and may confer better pain control up to one week after surgery. Future studies with larger sample sizes are necessary to adequately characterize the effect of postoperative single-dose ketamine on pain control in this population.

Polymorphisms in COMT and OPRM1 Collectively Contribute to Chronic Shoulder Pain and Disability in South African Breast Cancer Survivors'

Chronic shoulder pain and disability is a common adverse effect experienced by >40% of breast cancer survivors (BCS). Pain management protocols for acute and chronic pain include the use of opioids and opioid derivatives. Furthermore, pain-modulating genes, such as COMT and OPRM1, have been linked to the aetiology of chronic pain. This study aimed to investigate the association between genetic variants of major pain modulator genes and chronic pain/disability in BCS. Assessment of pain, disability and combined (pain and disability) symptoms were determined using the Shoulder Pain and Disability Index (SPADI). Participants were grouped according to their scores such as no-low (<30%) and moderate-high (≥30%) groups of pain, disability and combined (pain and disability). Genotyping of the COMT rs6269 (A > G), rs4633 (C > T), rs4818 (C > G) and the functional rs4680(G > A) SNPs within the BCS (N = 252) cohort were conducted using TaqMan^® SNP assays. Genotype, allele, haplotype, and allele-allele combination frequencies were evaluated. Statistical analysis was applied, with significance accepted at p < 0.05. The COMT rs4680:A/A genotype was significantly associated with moderate-high pain (p = 0.024, OR: 3.23, 95% CI: 1.33-7.81) and combined (pain and disability) (p = 0.015, OR: 3.81, 95% CI: 1.47-9.85). The rs4680:A allele was also significantly associated with moderate-high pain (p = 0.035, OR: 1.58, 95% CI: 1.03-2.43) and combined (pain and disability) (p = 0.017, OR: 1.71, 95% CI: 1.07-2.71). For the inferred COMT (rs6269 A > G-rs4680 G > A) haplotype analyses, the G-G (p = 0.026, OR: 0.67, 95% CI: 0.38-1.18) and A-A (p = 0.007, OR: 2.09, 95% CI: 0.89-4.88) haplotypes were significantly associated with reduced and increased likelihoods of reporting moderate-high pain, respectively. The inferred A-A (p = 0.003, OR: 2.18, 95% CI: 0.92-5.17) haplotype was also significantly associated with combined (pain and disability). Gene-gene interaction analyses further showed allele-allele combinations for COMT (rs4680 G > A)-OPRM1 (rs1799971 A > G) and COMT (rs4680 G > A)-OPRM1(rs540825 T > A) were associated with reporting pain and combined (pain and disability) symptoms, p < 0.05. The findings of this study suggest that COMT and OPRM1 SNPs play a role in the development of chronic shoulder pain/disability in BCS in a unique South African cohort from the Western Cape.