Clinical trial NCT04267315: Trigger Point Injections for Post-Mastectomy Pain Syndrome
Official title: Trigger Point Injections for Post-Mastectomy Pain Syndrome: A Double-Blind Randomized Controlled Trial With Intention-to-Treat Analysis
Study type: INTERVENTIONAL
Overall status: ACTIVE_NOT_RECRUITING
Phase: PHASE2
Conditions: Post-mastectomy Pain Syndrome
Myofascial Pain Syndrome
Trigger Point Pain, Myofascial
Breast Cancer
Lead sponsor: Instituto do Cancer do Estado de São Paulo
Sponsor class: OTHER
Collaborators: name: Hospital de Câncer de Barretos
First posted: 2020-02-12
Enrollment: 72
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Double-blind randomized controlled trial comparing the efficacy of TPI + standard of care (ACTIVE) versus sham TPI + standard of care(PLACEBO), with an intention-to-treat analysis
Primary purpose: TREATMENT

Brief summary: Post-Mastectomy Pain Syndrome (PMPS) is a chronic pain that persists for more than three months after a surgical breast procedure. It has 11-70% incidence in patients that underwent a breast surgery. It consists of mixed pain, frequently associated with myofascial pain, an specific type of muscular pain. Trigger point injections (TPI) are classically used for the treatment of myofascial pain in other painful conditions. However, there are no controlled trials assessing the efficacy of TPI in the treatment of PMPS. The intervention objective is to assess the efficacy of TPI in patients with PMPS, when associated with a comprehensive rehabilitation program and pain management.

Detailed description: INTRODUCTION: Post-Mastectomy Pain Syndrome (PMPS) is a chronic pain that persists for more than three months after a surgical breast procedure. It has 11-70% incidence in patients that underwent a breast surgery. It consists of mixed pain, frequently associated with myofascial pain. Trigger point injections (TPI) are classically used for the treatment of myofascial pain in other etiologies. However, there are no controlled trials assessing the efficacy of TPI in the treatment of PMPS

OBJECTIVE: Assess the efficacy of TPI in patients with PMPS, when associated with a comprehensive rehabilitation program and pain management.

METHODS: Double-blind randomized controlled trial with intention-to-treat analysis. Both groups will undergo standard of care delivered by Physiatrist blinded to group allocation. Active group will undergo TPI with 1% lidocaine in each identified trigger-point, weekly, for three consecutive weeks. Control group will undergo subcutaneous saline injection superficial to the same trigger points, with the same frequency and number of sessions. Primary outcome is the mean difference between groups for pain levels, as assessed by Visual Numeric Scale (VNS), from baseline to 3 months after the procedure.

STATISTICAL ANALYSIS: Difference between groups at baseline, one and three months after injection, using Analysis of Covariance (ANCOVA) for the following outcomes: VNS; Presence of active trigger points, Pressure pain threshold (PPT); Short-Form McGill Pain Questionnaire (SF-MPQ); Neuropathic Pain Symptom Inventory (NPSI); Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH); Range of motion (ROM) of affected shoulder, for abduction and external rotation; adverse events; use of pain medication.

Total sample size is 120. Alpha=5%, power=80%.

Eligibility criteria: Inclusion Criteria:

* Breast cancer patients.
* PMPS diagnosis, as per Wisotzky et col.

  * Pain \> 3 months over breast, chest wall or shoulder ipsilateral to surgery.
* Pain Visual analog Scale (VAS) ≥4.
* At least one active trigger point in the following muscles: pectoralis major, superior trapezius, serratus anterior, levator scapularis, latissimus dorsi, infraspinatus

Exclusion Criteria:

* Current radiation therapy or time since completion \< 3months.
* Allergy to lidocaine or other local anesthetics
* Active infection over injection sites
* Unavailability to be at the hospital during study intervention.

Primary outcomes:
measure: Visual Numeric Scale (VNS) for pain in 3 months
timeFrame: 3 months
measure: Trigger-points
timeFrame: 1 month
measure: Trigger-points
timeFrame: 3 months
measure: Pressure Pain Threshold (PPT)
timeFrame: 1 month
measure: Pressure Pain Threshold
timeFrame: 3 months
Secondary outcomes:
measure: Visual Numeric Scale (VNS) for pain in 1 month
timeFrame: 1 month
measure: Short-Form McGill Pain Questionnaire (SF-MPQ) - total score, sensorial and affective scale
timeFrame: 1 month
measure: Short-Form McGill Pain Questionnaire (SF-MPQ) - total score, sensorial and affective scale
timeFrame: 3 months
measure: Neuropathic Pain Symptom Inventory (NPSI)
timeFrame: 1 month.
measure: Neuropathic Pain Symptom Inventory (NPSI)
timeFrame: 3 months
measure: Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH)
timeFrame: 1 month
measure: Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH)
timeFrame: 3 months
measure: Shoulder range of motion (ROM)
timeFrame: 1 month
measure: Shoulder range of motion (ROM)
timeFrame: 3 months
measure: Percentage of patients with at least 30% improvement of pain as per VNS scores (VNS30%)
timeFrame: 1 month
measure: Percentage of patients with at least 30% improvement of pain as per VNS scores (VNS30%)
timeFrame: 3 months
measure: Percentage of patients with at least 50% improvement of pain as per VNS scores (VNS50%)
timeFrame: 1 month
measure: Percentage of patients with at least 50% improvement of pain as per VNS scores (VNS50%)
timeFrame: 3 months
measure: Adverse events
timeFrame: 1 month
measure: Adverse events
timeFrame: 3 months
measure: Pain medication
timeFrame: 1 months
measure: Pain medication
timeFrame: 3 months
Other outcomes:
Locations:
city: Barretos
country: Brazil
facility: Hospital de Câncer de Barretos
state: São Paulo
city: São Paulo
country: Brazil
facility: Instituto do Câncer do Estado de São Paulo
Study officials:
affiliation: Instituto do Câncer do Estado de São Paulo
name: Christina May Moran de Brito, MD, PhD
role: STUDY_DIRECTOR
References:
citation: Wisotzky E, Hanrahan N, Lione TP, Maltser S. Deconstructing Postmastectomy Syndrome: Implications for Physiatric Management. Phys Med Rehabil Clin N Am. 2017 Feb;28(1):153-169. doi: 10.1016/j.pmr.2016.09.003.