Bilateral Prophylactic Mastectomy; Should we Preserve the Pectoral Fascia? (PROFAS)

Bilateral Prophylactic Mastectomy; Should we Preserve the Pectoral Fascia?: Protocol of a Dutch Double Blinded, Prospective, Randomized Controlled Pilot Study With a Within-subject Design

Many surgical guidelines promote the removal of the pectoral fascia in mastectomies for invasive breast cancer, but there is no evidence to support this statement in (bilateral) prophylactic mastectomies. Reported wound-related local complications following mastectomy include seroma, flap necrosis, infection, hematoma, and nerve injury. Seroma causes discomfort and may delay the reconstructive procedures. Whether the removal or preservation of the pectoral fascia influences seroma formation following mastectomy remains unclear to our knowledge.

The primary objective of this pilot study is to investigate the impact of removal versus preservation of the pectoral fascia on drain policy and needle aspirations in women who undergo a bilateral prophylactic mastectomy. The secondary objective is to investigate the impact of removal versus preservation of the pectoral fascia on postoperative (surgical) complications. The study design includes a double-blinded, prospective, randomized controlled pilot study with a within-subject design. All patients will undergo a bilateral prophylactic mastectomy and randomization will occur within the patient. Preservation of the PF will be performed in one breast (intervention), while removal of the PF will be performed in the contralateral breast of the same patient (control). Consequently, the operation involves a total bilateral prophylactic mastectomy, with unilateral preservation of the PF The follow-up time of each patient will be 6 weeks. The patients' files will be viewed after the removal of the drain for additional recorded variables.

The patient and the observer for drain volume are both blinded for their assigned breast randomization. The surgeon(s) and coordinating researcher will not be blinded, and are therefore not allowed to measure the drain production.

A total mastectomy will be performed in the control breast: a procedure which includes removal of the breast glandular tissue including the PF and subcutaneously excision of the nipple-areolar complex, while the pectoralis muscle will be spared. As much of the healthy skin envelope will be preserved to enable the performance of an effective breast reconstruction afterwards. When a nipple-sparing mastectomy is performed, the skin envelope together with the nipple-areolar complex will be spared. The investigational part of the operation is preservation of the PF. Dissection of cutaneous flaps and the breast with or without the PF will be performed with electrocautery.

Inclusion Criteria: Female patient Scheduled for a bilateral prophylactic mastectomy in the Erasmus MC Academic Breast Cancer Centre in Rotterdam Ability to give written consent Adequate understanding of Dutch language Exclusion Criteria: History of diagnosis of invasive breast cancer or ductal carcinoma in situ (DCIS) Other malignancies