Prophylactic mastectomy and occult malignancy: Surgical and imaging considerations

Area of Science:

• Oncology
• Surgical Oncology
• Breast Surgery

Background:

• Sentinel node biopsy (SLNB) is debated for prophylactic mastectomy (PM).
• Current recommendations do not routinely include SLNB for PM.
• Assessing occult malignancy (OM) incidence in PM is crucial.

Purpose of the Study:

• To determine the incidence of occult malignancy (OM) in patients undergoing prophylactic mastectomy (PM).
• To evaluate the value of routine sentinel node biopsy (SLNB) in this patient population.
• To inform surgical recommendations regarding SLNB for PM.

Main Methods:

• Retrospective review of 772 patients undergoing prophylactic mastectomy (PM) over 5 years.
• Analysis of occult malignancy (OM) incidence in contralateral prophylactic mastectomy (CPM) and bilateral prophylactic mastectomy (BPM) specimens.
• Selective performance of SLNB in 86 patients.

Main Results:

• 39 occult malignancies (OM) identified: 17 invasive cancers and 22 DCIS.
• Low incidence of invasive OM (17/772 patients).
• Risk factors for OM included age, LCIS, and non-BRCA mutations; MRI was protective.

Conclusions:

• Routine SLNB offers low value for patients undergoing prophylactic mastectomy (PM) due to low invasive OM incidence.
• Selective SLNB may be considered for patients with specific risk factors.
• Consider SLNB for indeterminate imaging, discordant biopsies, LCIS, or non-BRCA mutations.