A Prospective, Randomized Study of the Possible Pain Relieving and Scar Tissue Modifying Properties of Lipotransplantation in a "Post Breast Therapy Pain Syndrome" Setting
In Denmark, breast cancer is the most common fatal cancer in women with more than 4700 new
cases annually. All patients are treated according to national guidelines developed by the
Danish Breast Cancer Cooperative Group (DBCG). Treatment primarily consists of surgical
removal of all or parts of the breast and simultaneous removal of one-or lymph nodes in the
ipsilateral axilla. Subsequently, there may be a need for additional treatment with
chemotherapy, radiation and / or anti-hormonal therapy, in order to reduce the risk of
Up to 60% of women who are treated surgically for breast cancer, will experience chronic
pain as a consequence of the treatment. This condition was previously referred to as "Post
Mastectomy Pain Syndrome", but because the condition is also seen after less extensive forms
of breast cancer surgery, the condition is now termed "Post Therapy Breast Pain Syndrome"
(PBTPS). PBTPS is defined as a neuropathic pain condition with pain localized to the axilla,
the medial part of the upper arm, chest and or chest wall of the side of surgery, lasting
more than three months after surgery and / or the end of treatment.
In 2011 Caviggioli et al. published a study where lipotransplantation to the mastectomy area
was found to have a significant analgesic effect. The aforementioned study is to date the
only published study in the field. However, it is not a randomized study. In order to obtain
further evidence of the apparent beneficial effect of lipotransplantation on pain, the
present study has been initiated.
Lipotransplantation is a fast and relatively non-invasive technique which is described in
detail by Coleman et al.. Additionally, in a study from 2008, Klinger et al. found that
lipotransplantation to burn scars in the face resulted in a significant improvement in the
patient's skin and scar quality and also reduced pain in the treated areas. The theoretical
basis for the scar and skin modifying effects of lipotransplantation has not yet been
finally understood. To the best of our knowledge, no studies have systematically
investigated and analysed the effects of lipotransplantation on the irradiated mastectomy
area on a histological level.
The purpose of the study
The purpose of this study is to investigate whether lipotransplantation to the pain affected
mastectomy area, could have an analgesic effect in women affected by Post Breast Therapy
Pain Syndrome. Secondary, we wish to investigate the scar and skin modulating effects of
lipotransplantation to the same area.
By carrying out immunohistochemical staining and subsequent stereoscopic microscopy of free
nerve endings in the skin biopsies taken before and after lipotransplantationen we wish to
determine whether changes in the number and type of free nerve endings is part of the
mechanism of pain reduction.
By histologically comparing the amount of elastin and the distribution of the different
types of collagen before and after lipotransplantation we also strive to illuminate the scar
tissue modelling effects of lipotransplantation.
- Lipotransplantation to the area under the scar tissue and the area under the
pain-afflicted area reduces the pain in women with PBTPS.
- The neuropathic pain in PBTPS is correlated to the number of free nerve endings
crossing the border between the dermis and the epidermis
- Lipotransplantation have a beneficial effect on the scar tissue structure and improves
the skin quality.
Women who have undergone unilateral mastectomy for breast cancer at Aarhus University
Hospital, Aarhus, Denmark and has finished their adjuvant postoperative radiation therapy at
least 6 months ago. Patients must have had pain localized to the area of the missing breast
for at least three months after adjuvant radiation therapy ended. A total of 60 patients
with PBTPS will be included.
Furthermore, a control group of 30 patients without PBTPS is to be included. The control
group will serve as a baseline group in regards to the nerve fibre properties of the skin in
the mastectomy area for patients who have undergone the same treatment but haven't developed
Patients with Post Breast Therapy Pain Syndrome (PBTPS)
Patients with PBTPS are randomly assigned to receive either lipotransplantation or no active
Regardless of randomization, the patient will be invited to three follow-up visits,
respectively 3, 6 and 12 months after inclusion/surgery. At each of the outpatient visits
the participant will be asked to complete the DoloTest ® and the Patient Scar Assessment
Scale. The clinician will complete the Observer Scar Assessment Scale and record the
consumption of pain medication. DoloTest ® is a validated, visual analogue questionnaire
designed to assess the patients experienced pain and impact on the patients daily life. Two
3-mm punch biopsies will be taken at inclusion and at the follow-up visits visits 3 and 12
months after inclusion, regardless of which group the patient was randomized to. One of the
3-mm skin punch biopsy is taken directly from the scar. The second 3-mm skin biopsy is taken
in the area of the missing breast the patient has designated as the most pain afflicted. If
the patient's pain trigger area is located directly in the scar, the second skin punch
biopsy will be taken at a distance of 1 cm from the scar.
Patients without PBTPS
The second control group, consisting of 30 women who have not developed PBTPS, will be
subjected to a 3-mm skin punch biopsy from the skin above their mastectomy scar. The group
will consist of patients who have opted for a secondary breast reconstruction, and the
biopsy will be taken during the reconstructive procedure to ensure minimal added risk and
The skin punch biopsies from the pain afflicted area will be fixed in 4% phosphate buffered
paraformaldehyde. After freezing, the tissue samples are cut into 50-micron thick sections.
Systematically sampled sections immunostained with rabbit anti-human Protein Gene Product
9.5 (a neuron-specific protein), and DAB-marked goat anti-rabbit as the secondary antibody.
The sections are then microscoped in an Olympus BX51 light microscope with an Olympus DP71
digital camera and Prior motorized board connected to a computer with Newcast stereology
software. Two goals can then be calculated: 1) the number of free nerve endings, which
crosses the border between dermis and epidermis per mm 2) the average nerve fibre length
density in the epidermis and / or dermis.
The skin punch biopsies from the mastectomy scar are fixed in formaldehyde for embedding in
paraffin. The tissue samples are cut into 1-2 micron thick sections and stained with
Picrosirius red (PR) colour. By using polarized light microscopy, the various subtypes of
collagen fibres may be visualized and differentiated. The thicker collagen fibres (type I)
are red-orange-yellow and the thinner collagen fibres (type III) are green. Furthermore, the
sections will be stained for elastin. Quantitatively, by means of the above-mentioned
method, changes in the volume fraction of collagen type I and III, and elastin may be
The minimal clinically relevant difference the study is looking for, is a Visual Analog Pain
score difference of 3. The common standard deviation was estimated from a similar study by
Caviggioli et al. in 2011, and set to be 2.96 on the Visual Analog Pain scale. We assume
that our standard deviation (SD) will be the same. Using the following formula: N = (Za +
Zb)2 x SD2 / dif2 where Za and Zb are the standardized normal deviations corresponding to
the selected levels of significance, SD is Standard Deviation and dif is the minimal
clinically relevant difference the study is looking for. The result is 16 patients in each
arm, totalling 32 patients, when the significance level is set at 5% and the power of the
study is set to 80%. We plan to include 30 patients in each group, which will increase the
power of the study to 97.5%. Statistical analyzes will be performed in collaboration with a
biostatistician from the Health Sciences Institution, Aarhus University, Denmark.
The project is supported by: Faculty of Health Sciences, University of Aarhus with three
full time equivalents, which is used to pay for full-time academic staff. Other project
expenses are to be covered by independent foundations and endowments that do not have an
influence on the study. None of the personnel in the project have a financial interest in
Compensation to the participating patients
The participating patients in the study will not receive any financial compensation.
However, documented travel expenses will be reimbursed.
Recruitment of participants
The patients will always be offered at least 24 hours of consideration before deciding to
give written consent to participate in the study. With the signing of the consent form, the
patient accepts the terms and conditions in the study. The patient may at any time and
without justification withdraw her consent to participate, without her decision affecting
her present or future treatment or any other rights the patient may have.
Patients with PBTPS are recruited during their routine visits at the department of oncology.
Patients without PBTPS are recruited at their standard visit before the breast
reconstructive procedure that they have opted for.
Publication of results
Negative, inconclusive and positive results from the study will be published in
internationally recognized, peer-reviewed, English-language journals with an interest in the
Ethical statement, side effects and risks
In the present project, data will be treated confidentially in accordance with the Danish
Act on Processing of Personal Data. Participants shall be informed both in writing and
orally prior to deciding to participate in the study. The participants are thus fully aware
of the projects purpose, background and methods, as well as what is expected from the
patient's role as a participant.
The participating patients are in the lipotransplantation group, offered an active
treatment, which if the current study program can confirm the foreign study, hopefully
reduces their daily pain and discomfort and thereby also their consumption of analgesia. If
the project provides positive results, the control group will, after the study has ended, be
offered the same active treatment.
The patients, which only after informed consent, is part of the project will, in connection
1. Lipotransplantation in general anaesthesia; only be exposed to the risk associated with
general anaesthesia. The patients in the present study have in relation to their
previous surgery for breast cancer been exposed to one or more interventions in general
2. Risks related to the actual lipotransplantation. At the donor site, there is a risk for
short-term tenderness and temporary discolouration. In the long term, a slightly rough
surface of the skin may arise. The advantage of the harvest of the fat graft is that
the patient achieves a visible improvement of the contour at the donor site.
3. The risk related to the skin punch biopsies: apart from a small scar 1-3 mm
corresponding to the place where the biopsy is collected, there is not assessed to any
risk of permanent injury or damage.
All interventions are carried out by experienced specialists in plastic surgery with several
years experience with lipotransplantation. The general anaesthesia is performed by
specialists in anaesthesiology, which are all part of the permanent team at the plastic
surgery department and therefore familiar with providing anaesthesia during the described
For patients with Post Breast Therapy Pain Syndrome:
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment
Pain in the mastectomy area
The pain in the area around the mastectomy will be measured using visual analog scales (DoloTest), at inclusion of the patient, and at three follow-up visits 3, 6 and 12 months after inclusion.
Alexander Juhl Andersen, M.D.
University of Aarhus
Denmark: The Regional Committee on Biomedical Research Ethics