Sentinel Lymph Node Biopsy for Prophylactic Mastectomy: Necessary Precaution or Unnecessary Procedure?

Area of Science:

• Oncology
• Surgical Oncology
• Breast Surgery

Background:

• The utility of sentinel lymph node biopsy (SLNB) in prophylactic mastectomy procedures is debated.
• Nipple-sparing mastectomy (NSM) is increasingly utilized for risk reduction.

Purpose of the Study:

• To assess the diagnostic yield of SLNB.
• To determine the incidence of occult malignancy in patients undergoing prophylactic NSMs.

Main Methods:

• A retrospective review of a prospectively maintained database of NSMs performed between 2007 and 2019.
• Analysis of clinicopathologic features, BRCA status, MRI findings, and SLNB results in patients undergoing prophylactic mastectomy.

Main Results:

• Occult malignancy was detected in 5.6% of prophylactic NSMs, more common in contralateral prophylactic mastectomy (CPM) than bilateral prophylactic mastectomy (BPM).
• SLNB positivity was rare (0.4%), with no macrometastatic disease identified.
• BRCA1/2 positivity was associated with a reduced risk of occult malignancy.

Conclusions:

• Occult malignancy and SLNB positivity are infrequent in prophylactic NSMs.
• Routine SLNB is not recommended; it should be reserved for high-risk patients.
• Personalized, risk-adapted strategies for axillary management and preoperative imaging are needed.