Meta-analysis of sentinel lymph node biopsy at the time of prophylactic mastectomy of the breast.

BACKGROUND Prophylactic mastectomy is performed to decrease the risk of breast cancer in women at high risk for the disease. The benefit of sentinel lymph node biopsy (SLNB) at the time of prophylactic mastectomy is controversial, and we performed a meta-analysis of the reported data to assess that benefit. METHODS We searched MEDLINE, EMBASE and the Cochrane Library databases from January 1993 to December 2009 for studies on patients who underwent SLNB at the time of prophylactic mastectomy. Two reviewers independently evaluated all the identified papers, and only retrospective studies were included. We used a mixed-effect model to combine data. RESULTS We included 6 studies in this review, comprising a total study population of 1251 patients who underwent 1343 prophylactic mastectomies. Of these 1343 pooled prophylactic mastectomies, the rate of occult invasive cancer (21 cases) was 1.7% (95% confidence interval [CI] 1.1%-2.5%), and the rate of positive SLNs (23 cases) was 1.9% (95% CI 1.2%-2.6%). In all, 36 cases (2.8%, 95% CI 2.0%-3.8%) led to a significant change in surgical management as a result of SLNB at the time of prophylactic mastectomy. In 17 cases, patients with negative SLNs were found to have invasive cancer at the time of prophylactic mastectomy and avoided axillary lymph node dissection (ALND). In 19 cases, patients with positive SLNBs were found not to have invasive cancer at the time of prophylactic mastectomy and needed a subsequent ALND. Of the 23 cases with positive SLNs, about half the patients had locally advanced disease in the contralateral breast. CONCLUSION Sentinel lymph node biopsy is not suitable for all patients undergoing prophylactic mastectomy, but it may be suitable for patients with contralateral, locally advanced breast cancer.