Sentinel Lymph Node Biopsy for Risk-Reducing Mastectomy

Abstract

Risk-reducing mastectomy (RRM) confers 90-95% decreased risk of breast cancer, and may reduce mortality, especially in high-risk groups such as BRCA carriers. Risk of occult disease in RRM specimen is ~5%. This demands axillary staging: sentinel lymph node (SLN) biopsy is no longer possible, axillary clearance confers significant risks and may prove negative. Contemporaneous SLN biopsy allows axillary staging with minimal further dissection. Women undergoing RRM and SLN biopsy between June 2005 and July 2010 were reviewed retrospectively from our prospectively maintained database of 1,522 SLN procedures in 1,498 patients. SLN(s) localized using routine tracer methods. SLNs and mastectomy specimens underwent routine histologic examination. Eighty-three RRMs with SLN biopsy were performed in 71 patients (12 bilateral). Indications for RRM: contralateral invasive (55), in situ (5) disease, BRCA 1/2 mutation (12), and strong family history (10). Mean number of SLNs: 1.35. Occult disease was detected in four cases (4.8%), with one case of occult invasive lobular carcinoma (1.2%). Remaining occult disease was lobular in situ neoplasia (LISN). SLNs were negative in all cases. Our findings are comparable to those in the literature: 4.8% rate of occult disease overall, 1.2% invasive. The significant risk with SLN biopsy is lymphoedema, quoted around 7%. We have had no reports of symptomatic lymphoedema in patients undergoing RRM and SLN biopsy. We propose that SLN at the time of mastectomy requires only limited further dissection, and confers minimal risk compared with secondary axillary surgery.

The Use of Sentinel Lymph Node Biopsy in BRCA1/2 Mutation Carriers Undergoing Prophylactic Mastectomy: A Retrospective Consecutive Case-Series Study

“…The median number of lymph nodes removed from operated breasts was 1 (range 1-2), which is in agreement with the results of other studies (1.35 [ 10 ], 1.46 [ 25 ], and 2 [ 31 ]). This assessment is important because a higher number of biopsied lymph nodes reduce the false negative rate but also increase morbidity.…”

“…Our group reinforces the importance of MRI at a short interval before surgery, since all our patients had a BRCA1/2 pathogenic mutation and, therefore, a higher risk both for occult and for interval carcinoma. In fact, in spite of being a high-risk group, the occult carcinoma incidence in our study (5%) was similar to that reported by others (6.0% [ 3 ], 4.8% [ 10 ], and 1.76% [ 31 ]) and the same can be concluded for our occult invasive carcinoma rate (2.5% versus 2% [ 17 ], 1.2% [ 10 , 31 ], and 0% [ 3 ]).…”

“…Sentinel lymph node biopsy is considered to have minimal surgical risk and avoids axillary lymphadenectomy if an occult carcinoma is found [ 10 , 11 ]. However, it is time-consuming and expensive and may cause complications including paresthesias, lymphedema, and arm motion limitation (with estimated risks of 9%, 2–7%, and 4%, resp.)…”

Role of Sentinel Lymph Node Biopsy During Contralateral Prophylactic Mastectomy

“…Although the risk of lymphedema was high in the group with ALND, they suggested SLNB use during CPM because they did not find any differences in lymphedema between the groups with and without SLNB. Burger et al (20) found only one occult ILC and three lobular in situ neoplasms in 83 PMs. They suggested SLNB because they did not see lymphedema in any patient and thought that adding SLNB did not prolong the duration of operation.…”

“…The surgeons using routine SLNB during CPM suggest that SLNB cannot be performed after mastectomy, so in case of occult invasive malignancy at CPM, ALND will be mandatory at the second session, which may cause an increase in morbidity. In addition, many authors suggest that they do not observe lymphedema or the risk is similar in the cases in which SLNB is not performed (1,4,20). They also state that SLNB is helpful to find possible cross-metastases from index tumor (1).…”