Prophylactic Mastectomy in Patients at High Risk: Is There a Role for Sentinel Lymph Node Biopsy?

IntroductionProphylactic mastectomy (PM) rates in the United States are rising due to determination of increased Gail risk, moderate-high risk lesions, a strong family history, and gene mutation carriers. The role of sentinel lymph node biopsy (SLNB) in PM remains controversial. This report sought to examine clinical utility of SLNB in PM.MethodsA total of 292 patients underwent bilateral or contralateral PM (1999-2011). SLNB was performed on the PM side in 195 (66.7%) patients with standard techniques. Clinicopathologic data were analyzed for the incidence of occult cancer in prophylactic breast and/or axilla. Univariate analysis was used to determine factors that predict SLN positivity.ResultsThe median patient age was 49 years (range, 19-79 years). Contralateral invasive breast cancer (64.7%) was the most common indication for PM. A total of 209 (71.5%) invasive breast cancer and 49 (16.7%) in situ cancers (n = 38 ductal carcinoma in situ, n = 10 lobular carcinoma in situ) were identified on the therapeutic mastectomy side, with a median tumor size of 1.5 cm. 58.6% were estrogen receptor positive and 4.7% were multicentric. Three (1%) ductal carcinoma in situ, 4 (1.3%) lobular carcinoma in situ, and 5 (1.7%) atypical ductal, and 1 (0.3%) lobular hyperplasia were identified in PM breast. No invasive breast cancer or positive SLN was identified in PM breast and/or axilla.ConclusionAlthough a minimally invasive procedure, the utility of SLNB in patients with absent or contralateral early disease is limited. Advanced T stage, multicentricity, or receptor status on the therapeutic side or a finding of in situ or atypical hyperplasia in prophylactic breast specimen yielded no positive SLN. Routine SLNB in pure bilateral PM can safely be omitted, which reduces axillary morbidity and operative time and/or cost. Selective use of SLNB for contralateral recurrent and/or locally advanced cancers warrants further investigation.