Pain characteristics as important contributing factors to upper limb dysfunctions in breast cancer survivors at long term.

PURPOSE: The aim of this study was to explore the treatment, patient, and impairment-related risk factors associated with upper limb dysfunctions in breast cancer survivors.

METHODS: A cross-sectional study was performed in 274 women treated for breast cancer. The following risk factors were analysed 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) and finally impairment-related variables such as pain (intensity, quality and pressure hypersensitivity, signs of central sensitisation, the degree of pain catastrophizing and vigilance and awareness to pain), active ROM and upper limb strength were investigated. The dependent variable was upper limb function measured with the Disability of Arm, Shoulder and Hand (DASH) questionnaire. Additionally, a stepwise regression was performed.

RESULTS: An impaired upper limb function was noted in 170 (62%) of patients. Mean time after surgery was 1.5 (1.6) years. From multivariable analysis, it appears that in particular certain pain characteristics such as pain intensity, pain quality, signs of central sensitisation and pain catastrophizing are contributing to upper limb dysfunctions after breast cancer treatment at long term. Additionally, higher age, shoulder ROM and handgrip strength are possible contributing factors. The stepwise regression analysis revealed that central sensitisation mechanisms alone can explain about 40% of the variance in upper limb function.

CONCLUSIONS: At long term, especially pain and central sensitisation mechanisms contribute to upper limb function in breast cancer survivors.