Identifying Biomarkers for Chronic Pain After Breast Cancer Treatment.

• Biomarkers (Diagnostic test), also known as Questionnaires: Depression Anxiety Stress Scales Short form, Pain Catastrophising Scale, VK+ and Positive and Negative Affect Schedule, Quantitative sensory testing: hyperalgesia using TSA2 (Medoc), Conditioned Pain Modulation using TSA2 (Medoc), Temporal Summation using monofilament (256mN Optihair-2 Set) and TSA2 (Medoc), Brain imaging: T1 MPRAGE, rsfMRI, Diffusion Weighted Image and T2 sequence., Blood analysis: Cytokine and Brain-Derived Neurotrophic Factor expression measurements, SNPs and CpG methylation detection.: Each intervention is performed at 4 timepoints namely: before surgery, i.e. baseline (T0), 1-3 weeks post-surgery (T1), 3 months post-surgery (T2) and 1 year post-surgery (T4)

Primary outcomes

• Localisation of pain [Time frame up to 1 year post-surgery]: Localisation and experience of pain after cancer treatment measured with the Mc Gill Pain Questionnaire Dutch Language Version: Anamnesis questions to localize the pain and the experience of the patient. Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery
• Pain intensity [Time frame up to 1 year post-surgery]: Visual Analogue Scale included in the Mc Gill Pain Questionnaire is a 100mm horizontal line were the patient is asked to indicate his/her perceived pain intensity at this moment, the minimum and the maximum of the pain. Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery
• Influence of pain on the quality of life [Time frame up to 1 year post-surgery]: Quality of Life questions included in the Mc Gill Pain Questionnaire: self-report to indicate the impact of pain on quality of life. The higher the score the higher the impact (0-27). Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery
• Severity of pain symptoms [Time frame up to 1 year post-surgery]: Adjective list of pain symptoms included in the Mc Gill Pain Questionnaire Dutch : Language Version (0-63): Self-report of pain evaluating the sensory intensity, emotional impact and the cognitive evaluation of pain. Each part or dimension of the MPQ is individually scored and a cumulative total score is also recorded. Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery

Secondary outcomes

• Prognostic value of Pain Catastrophizing [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: Pain Catastrophizing Scale (0-52) : It is a self-report measure, consisting of 13 items scored from 0 to 4, resulting in a total possible score of 52. The higher the score, the more catastrophizing thoughts are present.
• Prognostic value of Depression, Anxiety and Stress [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: Depression, Anxiety and Stress Scale (DASS-21) (range 0-132). The Depression, Anxiety and Stress Scale - 21 Items (DASS-21) is a set of three self-report scales designed to measure the emotional states of depression, anxiety and stress
• Prognostic value of Positive and Negative affect [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: Positive and Negative Affect Schedule (10-50): This scale consists of different words that describe feelings and emotions, it measures positive and negative affect. Lower scores representing lower levels of Positive/Negative Affect and higher scores representing higher levels of Positive/Negative Affect.
• Prognostic value of Resilience [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: VK+ : This scale gives an indication about the resilience of the patients (0-100). The higher the score, the more resilience is present.
• Prognostic value of hyperalgesia [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: Cold and hot detection and pain thresholds are measured as the first identified stimulus under increasing stimulus intensities. Thresholds are measured at local places to evaluate primary hyperalgesia and a distant location to assess secondary hyperalgesia. Results are compared with normative data.
• Prognostic value of conditioned pain modulation [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: 'Test' stimulus and a 'conditioning' stimulus applied is used to assess pain sensitivity to a warmth stimulus pre- and post the noxious conditioning stimulus and the difference is calculated between premeasures and postmeasures. When the second pressure pain threshold (i.e., test stimulus) is similar or lower than the first, dysfunctional inhibitory pain mechanisms are present.
• Prognostic value of temporal summation [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: Repetitive stimuli are given of which the perceived intensity of the stimulus (first, last and after sensations) is measured by a Numeric Rating Scale. The difference between the first and the last stimuli is calculated in order to determine the temporal summation. Enhanced temporal summation is considered as positive with at least two points of increase on the NRS
• Prognostic value of gray matter differences [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: T1 acquisition and Voxel-Based Morphometry is used to measure regional differences in gray matter. T2 acquisition is applied for possible co-registration and improving robustness for post-processing pipelines.
• Prognostic value of functional connectivity [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: Rs-fMRI acquisition is used to measure functional connectivity.
• Prognostic value of Fractional Anisotropy [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: Diffusion Weighted Imaging acquisition is used to assess differences in fractional anisotropy. T2 acquisition is applied for possible co-registration and improving robustness for post-processing pipelines.
• Prognostic value of the percentage CpG methylation in gene regions of selected cytokine and Brain Derived Neurotrophic Factor genes. [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: Genes associated with the persistent pain phenotype will be selected using multivariate analysis. CpG methylation is determined using bisulfate CpG pyrosequencing. PyroMark Q24 Analyses software will assess the average methylation of each CpG in the different gene regions of interest and return a percentage (from 0-100% methylation) as a result.
• Prognostic value of cytokine expression [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: Interested cytokines will be selected using multivariate analyses. Plasma samples will be assessed using a multiplex panel.
• Prognostic value of Brain Derived Neurotrophic factor expression [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: Measurements of soluble Brain Derived Neurotrophic factor expression is assessed using enzyme-linked immunosorbent assay.
• Prognostic value of single nucleotide polymorphisms (SNPs) [Assessment at T0: pre-surgery, T1: 1-3 weeks post-surgery, T2: 3 months post-surgery, T3: 1 year post-surgery]: A total of 82 SNPs from 15 cytokine genes and 2 SNPs of brain derived neurotrophic factor will be analysed using a SNP genotyping assay.

Sex: Female, ages: 25 Years to 65 Years

Inclusion Criteria:

* Unilateral breast cancer
* Pain at enrollment <3/10 on average during the past week
* First cancer diagnosis

Exclusion Criteria:

* Pre-existing pain conditions
* major pre-existing neurological disorders
* No recurrent cancer or metastasis
* No previous surgery in area

• Mira Meeus, Prof., Principal investigator, Universiteit Antwerpen
• An De Groef, Prof., Study chair, Universiteit Antwerpen