[211] Contralateral Prophylactic Sentinel Lymph Node Biopsy (CP-SLNB) for Breast Carcinoma: Too Much Dissection for Too Little Gain?

J Hart, M Fiel-Gan, E Brady, R Ringer, A Ricci, Jr. Hartford Hospital, Hartford, CT

Background: The potential value of performing contralateral prophylactic sentinel lymph node biopsy (CP-SLNB) has been incompletely studied. In theory if an invasive carcinoma were to be found in a contralateral prophylactic mastectomy (CPM), a CP-SLBN would obviate the need for contralateral axillary dissection. However the chance of finding contralateral carcinoma is generally believed to be low. To address this question more fully we reviewed our most recent 6 year-experience with CP-SLNB.
Design: Our institution's surgical pathology files were queried for all specimens coded as “mastectomy”. An intentionally “wide net” was cast in order to fully maximize catchment. This voluminous list was then culled by hand to include cases of CPM for: (1) patients undergoing total mastectomy for recently diagnosed ipsilateral carcinoma, (2) patients reporting a history of ipsilateral carcinoma previously treated by mastectomy and (3) patients undergoing bilateral mastectomies without a diagnosis of breast carcinoma (this included women with atypia, lobular neoplasia, positive family history, genetic mutations, and one woman with ovarian carcinoma). Excluded were contralateral mastectomies performed for a suspicious lesion or biopsy proven carcinoma. Data were abstracted from anonymized surgical pathology reports to include age, laterality, ipsilateral primary cancer histology, contralateral histology and CP-SLNB results, as well as any available clinical history.
Results: During 2004-2009 there were 226 patients undergoing CPM and there was increasing utilization of CPM over this interval (i.e. 10, 29, 33, 38, 50 & 66 per annum, respectively). Patients were all women aged 29-78 yr. (mean 48.8). Of these 226, 176 (78%) also underwent CP-SLNB. A total of 391 CP-SLN were harvested (mean 2.22). There were isolated CK(+) cells in a single lymph node from one patient (2 additional intramammary LN were negative). This 37-year-old woman had ipsilateral DCIS and pleomorphic LCIS and had recently had tested BRCA positive. The PCM showed only DCIS after extensive sectioning.
Conclusions: The positive yield of CP-SLNB is extremely low. In this study there was only a 0.57% (1/176) incidence of N0[i+] disease and not even a single N1 case. Even considering the highest risk individuals (i.e. BRCA positive with ipsilateral carcinoma), it may soon become standard of care to forgo CP-SLNB in most CPM.
Category: Breast

Tuesday, March 23, 2010 9:30 AM

Poster Session III # 37, Tuesday Morning


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