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
Assessment of Central Sensitization in Breast Cancer Survivors: Convergent Validity and Use of the Central Sensitization Inventory (CSI) and Its Short-Form as a Clustering Tool
