Unraveling Self-Reported Signs of Central Sensitization in Breast Cancer Survivors with Upper Limb Pain: Prevalence Rate and Contributing Factors

Abstract

Background: Hypersensitivity of the central nervous system to environmental and chemical stimuli is a clinical feature of central sensitization mechanisms that can be assessed with the central sensitization inventory (CSI). Objective: The aim was to determine prevalence rate of this feature and explore the treatment-, patient-, pain-, and psychosocial-related variables associated with the degree of self-reported signs of central sensitization, assessed with the CSI (0-100), in breast cancer survivors at long-term. Study Design: Cross-sectional study. Setting: University Hospitals, Leuven, Belgium. Methods: One hundred and forty-six women with persistent pain, more than one year after breast cancer surgery, were included. The following factors were analyzed by bivariable and multivariable analysis: 1) treatment-related variables (type of surgery, levels of lymph node dissected, radiotherapy, chemotherapy, hormone therapy, and trastuzumab); 2) patient’s related variables (age and body mass index); 3) pain-related variables (pain intensity, pain quality, primary hyperalgesia, and index of widespread pain); and 4) psychosocial variables (the degree of pain catastrophizing and vigilance and awareness to pain). The dependent variable was degree of central sensitization measured with the CSI. Additionally, a stepwise regression was performed. Results: Fifty-five (38%) patients reported signs of central sensitization measured with the CSI (i.e., > 40/100). From multivariable analysis, it appears that more severe pain quality and higher levels of pain catastrophizing contribute to a higher degree of central sensitization. The stepwise regression revealed that up to 24% of variance of the CSI can be explained by these factors. Limitations: A selection bias may be present since patients were all recruited from a larger cohort participating in clinical trials on the effectiveness of physical therapy after breast cancer treatment. Conclusion: Signs of central sensitization cannot be neglected in breast cancer survivors at long term. More severe pain quality and pain catastrophizing contribute to higher levels of central sensitization in this population. Key words

Structural validity and reliability of the Spanish Central Sensitization Inventory in breast cancer survivors

“…According to established clinical values, women had mild levels of CS symptoms 7 . These values are in line with previous research reporting a mean CSI overall score in the BCS population 5,6,16,17 . However, CSI values ranged from 0 to 73, representing a heterogeneity in this sample.…”

“…The original English version of CSI is a valid and reliable tool that has been developed to assess symptoms that are related to CS and it has been translated and validated in different languages, including Dutch, Spanish, and Brazilian 12–15 . Moreover, CSI has been previously used to measure CS symptoms in BCS 5,6,16,17 . Although this Patient Reported Outcome Measure (PROM) has been translated and validated in Spanish patients with chronic musculoskeletal pain, no psychometric analysis has been carried out in BCS 12 .…”

Self‐reported signs and symptoms of secondary upper limb lymphoedema related to breast cancer treatment: Systematic review

“…In addition to the nociceptive and neuropathic problems described above, sensitisation of the central nervous system (including widespread pain hypersensitivity, enhanced temporal summation and efficacious endogenous descending pain inhibition) may contribute as well to the wide range of self‐reported signs and symptoms, in particular ‘pain’ (Edwards et al, 2013). It was found that 38% of breast cancer survivors with pain more than 1 year after breast cancer surgery had self‐reported symptoms of central sensitisation (De Groef et al, 2018). For these reasons, clinically, to determine if an individual's pain and other signs and symptoms are primarily associated with ULL, a thorough assessment by clinicians who have experience in both pain and lymphoedema is needed.…”

EduCan trial: study protocol for a randomised controlled trial on the effectiveness of pain neuroscience education after breast cancer surgery on pain, physical, emotional and work-related functioning

“…In fact, 12%–82% of women still report persistent pain 1 year or later 4. This may indicate that besides local nociceptive and neuropathic pain mechanisms, a third pain mechanism characterised by altered nociceptive processing without clear evidence of persistent tissue damage causing the activation of peripheral nociceptors (ie, nociceptive pain) or evidence for disease or lesion of the somatosensory system causing the pain (ie, neuropathic pain) 6–8. Moreover, pain interferes with pain, physical, emotional and work-related disability and therefore severely prejudices a person’s quality of life and participation in society 9–11.…”

“…Through the knowledge that pain is often an unreliable indicator of the presence or extent of tissue damage and if patients may become open to exploring broader contributions to pain, pain-related behaviour might change by shifting from passive therapy receiving to active self-management. Increased knowledge of the broad contributions to pain,4 as well as awareness of different pain mechanisms following breast cancer treatment6–8 provides justification for the integration of PNE in this population. Applying PNE could enhance the effectiveness of the currently applied physical therapy modalities for prevention and treatment of pain and related disabilities after breast cancer treatment, compared with a traditional biomedical educational intervention.…”