This study evaluates the possible beneficial effect of fat grafting for post mastectomy pain syndrome. Half of patients will receive fat grafting and the other half of patients will receive sham.

Several studies have suggested that fat grafting can alleviate pain in post mastectomy pain syndrome. These studies however have either been in the form of case series or unblinded studies with great risk of bias.

It is believed that fat grafting with its content of adipose-derived stem cells can modulate the scar tissue upon grafting and hereby decrease pain.

In this study patients will be randomized to either fat grafting or a sham procedure where they undergo the same liposuction but no fat grafting, only injection of saline instead of fat.

Inclusion Criteria:

• Treated for breast cancer
• Pain in the breast cancer treated area on the breast or axilla.
• Pain present at least 4 days a week with an intensity above 3 on VAS.
• Duration longer than 3 months
• Recurrence free for minimum 6 months
• Understand the nature of the study and can give informed consent

Exclusion Criteria:

• Psychiatric condition that can affect participation.
• Recurrence of breast cancer at any time.
• Other indication for fat grafting other than pain treatment.
• Breast reconstruction with flap

During general anesthesia, patients are randomized to either fat grafting or sham grafting with only saline. All patients undergo the same liposuction. Participants are blinded, care providers postoperatively are blinded. The surgeon performing the procedure is not blinded. The outcome assessors 3 and 6 months postoperatively are blinded.