Is Routine Sentinel Lymph Node Biopsy Indicated in Women Undergoing Contralateral Prophylactic Mastectomy? Magee-Womens Hospital Experience

Systematic review of synchronous contralateral axillary metastases in breast cancer: really M1 disease?

OBJECTIVE

The objective of the study is to assess and quantify the effect of the appearance of synchronous contralateral axillary on breast cancer survival. Breast cancer with contralateral axillary metastases (CAM) is classified as a metastatic disease. There are few cases reported and a lack of evidence of the significance of CAM when synchronous appearance with a primary tumor and no other site of disease.

METHODS

A systematic review following PRISMA guidelines to evaluate the prognosis of patients with synchronous CAM without other metastatic diseases comparing with metastatic disease is conducted through a search in PubMed, Embase, Clinical Key, and Cochrane Library databases. We present one case. The median age, follow-up, clinico-pathological characteristics, status of lymph nodes, treatments, and outcomes are analyzed.

RESULTS

A total of 23 articles (10 case reports and 13 case series) with a total 68 patients, including our case. Median age was 48 years old. Median follow-up was 27 months. Overall survival of the series was 71.4%. Twenty-one of 49 patients reported (36.2%) were alive without disease, fourteen (28.6%) were alive with disease while the rest fourteen (28.6%) died. Inflammatory presentation and ipsilateral axilla status were related to overall survival.

CONCLUSIONS

Synchronous CAM in breast cancer show better outcomes in terms of overall survival than other metastatic diseases. The absence of comparative studies may not allow definitive conclusions, meanwhile, together with other authors we suggest treatment with curative intention. More studies may lead to consider a modification of TNM system.

Nipple sparing mastectomy techniques: a literature review and an inframammary technique

Nipple sparing mastectomy (NSM) has quickly become an accepted technique for patients with selected cancers and for risk reducing surgery. Much of its surgical acceptance over the last decade has been based on the low risk of nipple areolar complex (NAC) occurrence in breast cancer patients. Improved patient satisfaction due to improved cosmetic outcomes with reconstruction have also driven its popularity. We reviewed current English journals to determine the NSM techniques which achieve the lowest complications, best outcomes, and best patient satisfaction. We researched studies showing reductions in complications with improved surgical techniques and patient selection which have been implicated in improved results. In the studies reviewed, incision placement, away from the nipple, resulted in the lowest rates of ischemic nipple complications and the best cosmetic outcomes. The effect of other factors such as surgeon experience and thickness of skin flap development were more difficult to prove. Leaving a 2-3 mm rim of tissue around the nipple bundle was shown to help preserve the nipple vascularity. Lower complication rates with improved outcomes and patient satisfaction were reported in the literature in patients with B or smaller cup sizes, non-smokers, and patients with lower body mass index (BMI). Incision placement, away from the nipple, with preservation of a 2-3 mm rim of tissue around the nipple bundle along with careful patient selection were the most significant variables reviewed which helped to lower complications rates of NSM. Coordinated surgical planning with the breast and plastic surgeons to determine the best surgical approach for each individual patient is necessary to obtain the best results. Although short-term oncologic follow-up seems to be acceptable, longer follow-up will still be needed to define the best breast cancer surgical candidates for the nipple sparing approach.

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

INTRODUCTION

Sentinel lymph node biopsy in prophylactic mastectomy is controversial. It avoids lymphadenectomy in occult carcinoma but is associated with increased morbidity. Women with BRCA mutations have a higher incidence of occult carcinoma and our objective was to assess the clinical utility of sentinel lymph node biopsy when these women undergo prophylactic mastectomy.

MATERIALS AND METHODS

Seven-year retrospective consecutive case-series study of women, with a BRCA deleterious mutation, admitted to prophylactic mastectomy, at our center. Breast MRI < 6 months before surgery was routine, unless contraindicated.

RESULTS

Fifty-seven patients (43% BRCA1; 57% BRCA2) underwent 80 prophylactic mastectomies. 72% of patients had had breast cancer treated before prophylactic mastectomy or synchronously to it. The occult carcinoma incidence was 5%, and half of the cases were invasive. SLNB was performed in 19% of the prophylactic mastectomies; none of these had tumor invasion. Women with invasive carcinoma who had not undergone sentinel lymph node biopsy were followed closely with axillary ultrasound. The median follow-up was 37 months, with no local recurrence; 1 patient died of primary tumor systemic relapse.

CONCLUSIONS

Our data do not support this procedure for routine (in agreement with previous literature), in this high risk for occult carcinoma population.

Selective Use of Sentinel Lymph Node Surgery in Patients Undergoing Prophylactic Mastectomy Using Intraoperative Pathology

BACKGROUND

Routine sentinel lymph node (SLN) surgery during prophylactic mastectomy (PM) is unnecessary, because most PMs do not contain cancer. Our institution utilizes intraoperative pathology to guide the surgical decision for resection of SLNs in PM. The purpose of this study was to review the effectiveness of this approach.

METHODS

We identified all women aged ≥18 years who underwent bilateral PM (BPM) or contralateral PM (CPM) at our institution from January 2008 to July 2016. We evaluated the frequency of SLN resection and rate of occult breast cancer (DCIS or invasive disease) in the PM. We used the following definitions: over-treatment-SLN surgery in patients without cancer; under-treatment-no SLN surgery in patients with cancer; appropriate treatment-no SLN in patients without cancer or SLN surgery in patients with cancer.

RESULTS

PM was performed on 1900 breasts: 1410 (74.2%) CPMs and 490 (25.8%) BPMs. Cancer was identified in 58 (3.0%) cases (32 invasive disease and 26 DCIS) and concurrent SLN surgery was performed in 44 (75.9%) of those cases. Overall, SLN surgery guided by intraoperative pathology resulted in appropriate treatment of 1787 (94.1%) cases: 1319 (93.5%) CPMs and 468 (95.5%) BPMs, by avoiding SLN in 1743/1842 cases without cancer (94.6%), and performing SLN surgery in 44/58 cases with cancer (75.9%).

CONCLUSIONS

Use of intraoperative pathology to direct SLN surgery in patients undergoing PM minimizes over-treatment from routine SLN in PM and minimizes under-treatment from avoiding SLN in PM, demonstrating the value of intraoperative pathology in this era of focus on appropriateness of care.

The value of breast MRI in high-risk patients with newly diagnosed breast cancer to exclude invasive disease in the contralateral prophylactic mastectomy: Is there a role to choose wisely patients for sentinel node biopsy?

The aim of this study was to evaluate the presence of clinically and mammographically occult disease using breast MRI in a cohort of cancer patients undergoing contralateral prophylactic mastectomy (CPM) and the utmost indication of axillary assessment (sentinel node biopsy (SLNB)) for this side. A retrospective review of patients with unilateral invasive breast cancer or ductal carcinoma in situ (DCIS) from institutional MRI registry data (2004–2010) was conducted. Characteristics of patients undergoing CPM with breast MRI obtained less than 6 month before surgery were evaluated. A total of 2322 consecutive patients diagnosed with DCIS or stage I to III infiltrating breast cancer underwent preoperative breast MRI. Of these, 1376 patients (59.2%) had contralateral clinical breast exam and mammography without abnormalities; and 116 patients (4.9%) underwent CPM (28 excluded patients had breast MRI more than 6 months before CPM). The mean age of the 88 patients was 49 years (range 28–76 years). Two (2.3%) DCIS identified on surgical pathology specimen were not depicted by MRI and the 5 mm T1N0 invasive cancer (1.1%) was identified on MRI. Preoperative MRI showed 95% accuracy to demonstrate absence of occult disease with negative predicted value (NPV) of 98% (95% CI: 91.64–99.64%). Occult disease was present in 3.4% of CPM. MRI accurately identified the case of invasive cancer in this cohort. The high negative predictive value suggests that MRI can be used to select patients without consideration of SLNB for the contralateral side.

Is Sentinel Lymph Node Biopsy Necessary in Patients Undergoing Prophylactic Mastectomy? A Systematic Review and Meta-Analysis

The gain by performing sentinel lymph node biopsy (SLNB) during prophylactic mastectomy (PM) is debatable, and we performed a meta-analysis of existing literature to evaluate that the role of SLNB in subjects undergoing PM. A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google Scholar, Science Direct, and Web of Science. The search identified 11 relevant articles reporting on patients who underwent SLNB at the time of PM. Data were abstracted from each study and used to calculate a pooled odds ratio (OR) and 95% confidence interval (95% CI). We included 14 studies comprising of 2,708 prophylactic mastectomies. Among 2,708 prophylactic mastectomies, the frequency of occult invasive cancer (51 cases) was 1.8% and the rate of positive SLNs (33 cases) was 1.2%. In 25 invasive cancers at the time of PM were found to have negative SLNs which avoided axillary lymph node dissection (ALND). In seven cases with positive SLNBs were found not to have invasive cancer at the time of PM and needed a subsequent ALND. Most of the patients with positive SLNs had locally advanced disease in the contralateral breast. SLNB may be suitable for patients with ipsilateral, locally advanced breast cancer and is not recommend for all patients undergoing PM.

Increasing trend of contralateral prophylactic mastectomy: what are the factors behind this phenomenon?

INTRODUCTION

Numerous studies have shown a trend towards increasing rates of contralateral prophylactic mastectomy (CPM) in the US. In this review, we will explore the trend, possible causative factors and outcomes from CPM.

METHODS

We performed a literature review of all relevant retrospective reviews, clinical trials and review articles regarding contralateral prophylactic mastectomy.

RESULTS

Several studies have noted a four to fivefold increase in CPM in recent years; an increase most notable in younger patients. When surveyed, patients report that the most important factors affecting their choice of CPM include fear of cancer recurrence, genetic counseling/testing, family history or additional high risk factors, stress surrounding close follow up, the availability of reconstructive surgery and information provided about contralateral breast cancer (CBC) risk and risk for local recurrence. Women who have undergone CPM do report high satisfaction with the procedure and some studies suggest risk reduction.

CONCLUSION

CPM rates have increased across the US and numerous factors have been reported to increase the likelihood of choosing CPM. Despite that bilateral mastectomy is associated with an increased risk of wound and overall postoperative complications for certain populations, this surgery appears to have psychological, cosmetic and possibly oncologic benefit.

Oncoplastic surgery in the treatment of breast cancer

Advances in reconstructive breast surgery with new materials and techniques now allow us to offer our patients the best possible cosmetic results without the risks associated with oncological control of the disease. These advances, in both oncological and plastic surgery, have led to a new specialisation, namely oncoplastic breast surgery, which enables us to undertake large resections and, with advance planning, to prevent subsequent deformities. This is particularly important when more than 30% of the breast volume is removed, as it allows us to obtain precise information for conservative surgery according to the site of the lesion, and also allows us to set the boundary between conservative surgery and mastectomy.Given the existence of new alloplastic materials and new reconstructive techniques, it is essential for our patients that surgeons involved in breast cancer treatment are trained in both the oncological as well as the reconstructive and aesthetic fields, to enable them to provide the best loco-regional treatment with the best cosmetic results.

Prophylactic Mastectomy: An Appraisal

The main indication of prophylactic mastectomy pertains to BRCA1 or BRCA2 mutation carriers. Prophylactic mastectomy includes the simple method and the subcutaneous method. Both methods can be followed by breast plastic reconstruction either at the same time or later. This review examines key issues regarding prophylactic mastectomy: the selection of patients, its effectiveness, its limitations, convergence/divergence in existing guidelines, and future perspectives.

Prophylactic mastectomy in patients at high risk: is there a role for sentinel lymph node biopsy?

INTRODUCTION

Prophylactic 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.

METHODS

A 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.

RESULTS

The 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.

CONCLUSION

Although 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.

Sentinel lymph node biopsy at the time of mastectomy does not increase the risk of lymphedema: implications for prophylactic surgery

Women diagnosed with or at high risk for breast cancer increasingly choose prophylactic mastectomy. It is unknown if adding sentinel lymph node biopsy (SLNB) to prophylactic mastectomy increases the risk of lymphedema. We sought to determine the risk of lymphedema after mastectomy with and without nodal evaluation. 117 patients who underwent bilateral mastectomy were prospectively screened for lymphedema. Perometer arm measurements were used to calculate weight-adjusted arm volume change at each follow-up. Of 234 mastectomies performed, 15.8 % (37/234) had no axillary surgery, 63.7 % (149/234) had SLNB, and 20.5 % (48/234) had axillary lymph node dissection (ALND). 88.0 % (103/117) of patients completed the LEFT-BC questionnaire evaluating symptoms associated with lymphedema. Multivariate analysis was used to assess clinical characteristics associated with increased weight-adjusted arm volume and patient-reported lymphedema symptoms. SLNB at the time of mastectomy did not result in an increased mean weight-adjusted arm volume compared to mastectomy without axillary surgery (p = 0.76). Mastectomy with ALND was associated with a significantly greater mean weight-adjusted arm volume change compared to mastectomy with SLNB (p < 0.0001) and without axillary surgery (p = 0.0028). Patients who underwent mastectomy with ALND more commonly reported symptoms associated with lymphedema compared to those with SLNB or no axillary surgery (p < 0.0001). Patients who underwent mastectomy with SLNB or no axillary surgery reported similar lymphedema symptoms. Addition of SLNB to mastectomy is not associated with a significant increase in measured or self-reported lymphedema rates. Therefore, SLNB may be performed at the time of prophylactic mastectomy without an increased risk of lymphedema.

Routine prophylactic sentinel lymph node biopsy is not indicated in women undergoing prophylactic mastectomy

BACKGROUND

Prophylactic mastectomies (PM) are performed to reduce the risk of breast cancer. Occasionally an occult carcinoma is found in PM specimens. Given the high morbidity of axillary lymph node dissection (ALND), some perform prophylactic sentinel lymph node biopsy (SLNB). We undertook a study to examine if prophylactic SLNB is indicated in all patients undergoing PM.

METHODS

A retrospective review of all PM between 2004 and 2010 was performed. The stage of tumor on the disease side and the pathologic findings in the prophylactic breast were analyzed. The number of SLN and the frequency of lymph node metastases were evaluated.

RESULTS

A total of 199 PM on 184 patients were performed: 169 contralateral PM and 30 bilateral PM. Of the 199 PM, 12 had occult carcinomas (6.0%): 10 non-invasive, 1 microinvasive and 1 T1b invasive tumor. 153 of 199 PM specimens had prophylactic SLNB, of which only 2 had a positive SLN that originated from the index side of the breast.

CONCLUSIONS

Although it is not uncommon to find occult carcinomas in the prophylactic breast, it is rare for the occult carcinoma to spread to the lymph nodes. Therefore, routine prophylactic SLNB is not indicated in patients undergoing PM.

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.

The role of sentinel node biopsy in women undergoing prophylactic mastectomy

BACKGROUND

Sentinel lymph node (SLN) biopsy in patients undergoing prophylactic mastectomy (PM) remains controversial. We sought to determine the incidence of finding occult cancer and the frequency of SLN positivity in patients undergoing contralateral PM.

METHODS

Medical records of patients undergoing bilateral mastectomy at our institution from 2003 to 2008 were reviewed (n = 115). Eight patients (6.9%) had known bilateral cancer; an additional eight patients (6.9%) underwent BPM for risk reduction. The remaining 99 patients who had ipsilateral breast cancer and underwent contralateral PM formed the cohort of interest for this study. Univariate and multivariate analyses to determine factors correlating with occult malignancy and SLN positivity in the PM specimen were performed using SPSS ver. 17 (SPSS Inc., Chicago, IL).

RESULTS

The median patient age was 50 y, and median ipsilateral tumor size was 1.7 cm. Occult contralateral malignancy was found in eight (8.1%); of these, six (75.0%) had DCIS only. A positive SLN was found on the prophylactic side in 2 (2.0%) patients. Both had ipsilateral inflammatory cancer, and over 15 positive ipsilateral lymph nodes post-neoadjuvant chemotherapy. Ipsilateral inflammatory breast cancer was correlated with the finding of invasive cancer in the contralateral PM (P = 0.006), and both the finding of ipsilateral inflammatory breast cancer and number of positive lymph nodes correlated with the finding of a positive contralateral SLN.

CONCLUSION

The incidence of occult malignancy in PM is low (2%). However, patients with ipsilateral inflammatory cancer are at high risk of contralateral malignancy; SLN biopsy on the prophylactic side in these patients may be warranted.

Indications for sentinel lymph node biopsy in the setting of prophylactic mastectomy

BACKGROUND

Bilateral/contralateral prophylactic mastectomy (PM) is offered to high-risk women to decrease their actual or perceived breast cancer risk. When an invasive occult cancer is identified, prevailing wisdom suggests that an axillary dissection be performed. This single-institution study aims to identify patients who may benefit from sentinel node biopsy (SLNB) at the time of prophylactic mastectomy.

STUDY DESIGN

We performed a retrospective review of a prospective database of patients treated at our institution with bilateral/contralateral PM between 1995 and 2006. We examined patients' clinicopathologic characteristics in comparison with their incidence of occult cancer in the contralateral breast or axilla.

RESULTS

There were 449 patients who underwent PM and SLNB. Twenty-eight underwent bilateral PM. Of the 28, no occult cancers were identified. Occult cancers were identified in 18 of 420 (4.3%) contralateral prophylactic specimens; they were invasive in 6 (1.4%). In cases of occult carcinoma, the primary established tumor was more likely to be of invasive lobular histology. Eight of 420 (2%) patients had a positive contralateral sentinel node, and within this subset of 8 patients the majority had locally advanced disease on the known tumor side. Other features associated with a positive contralateral sentinel node included the presence of lymphovascular involvement or skin or nipple involvement and grade 2 to 3 invasive primary established tumors.

CONCLUSIONS

Overall, SLNB in patients undergoing bilateral PM or contralateral PM associated with early-stage disease is not indicated. But patients with locally advanced primary breast cancers have a significantly increased risk of occult cancer in the contralateral axilla, likely due to crossover metastasis; this select group of patients may benefit from SLNB at the time of surgery.

Sentinel lymph node biopsy in breast cancer: a comprehensive literature review

Sentinel lymph node biopsy has emerged as the new standard of care for nodal staging in early-stage breast disease. In the this review, the procedure of SLNB in breast cancer will be examined in greater detail with the aim of understanding techniques that may improve results and of identifying future research questions in this field.

Feasibility of sentinel lymph node biopsy through an inframammary incision for a nipple-sparing mastectomy

BACKGROUND

Nipple-sparing mastectomy (NSM) via an inframammary (IM) incision has been described for selected patients with breast cancer. However, the application of sentinel lymph node (SLN) mapping via an IM incision for NSM has yet to be reported. The objective of this study is to determine the technical feasibility of performing SLN through an IM incision without making an axillary counterincision.

METHODS

We retrospectively reviewed our single-institutional experience with SLN biopsy and NSM through IM incisions between January 2006 and March 2008. Clinicopathologic factors were analyzed regarding indications, technical details, postoperative morbidity, and follow-up.

RESULTS

Fifty-two patients underwent 87 NSM through an IM incision (17 unilateral, 35 bilateral) with immediate reconstruction and SLN biopsy. Indications for surgery included invasive breast cancer (n = 21), ductal carcinoma in situ (DCIS) (n = 18), and prophylactic (n = 48). Mean tumor size of invasive carcinoma was 2.1 cm. The mean mastectomy specimen weight was 437 g. Subareolar injection consisted of blue dye (n = 43), technetium sulfur colloid (n = 2), or combination injection (n = 42). SLN biopsy through an IM incision was successfully performed in 84 of 87 cases (96.6%). A mean of 2.8 SLN were removed with a positive sentinel node encountered in 8 of 21 patients (38%) with invasive cancer. No complications were observed regarding the SLN portion of the operation. With a median follow-up of 6.5 months (range, 0.4-23 months), there have been no axillary local recurrences.

CONCLUSION

SLN biopsy can be performed through an IM incision during a NSM, avoiding a secondary axillary incision.

Decision analysis to assess the efficacy of routine sentinel lymphadenectomy in patients undergoing prophylactic mastectomy

BACKGROUND

Patients who have invasive breast cancer identified after prophylactic mastectomy (PM) require axillary lymph node dissection (ALND) for lymph node staging (ie, directed ALND). Because the majority of these patients will be lymph node negative, sentinel lymphadenectomy (SLND) has been advocated at the time of PM to avoid the sequelae of unnecessary ALND. The objective of this study was to compare the efficacy of 2 surgical strategies, routine SLND versus directed ALND, in PM patients.

METHODS

A decision-analytic model was created to compare the 2 surgical strategies. Model estimates were derived from a systematic literature review. The endpoints that were examined to compare the 2 strategies were the number of SLNDs performed per breast cancer detected, the number of SLNDs attempted to avoid 1 ALND in a lymph node-negative patient with occult invasive cancer, and the number of axillary complications associated with each strategy.

RESULTS

The prevalence of invasive cancer in patients undergoing PM was estimated at 1.9%. At this rate, 37 SLNDs were performed per 1 breast cancer detected, and 73 SLNDs were required to avoid 1 ALND in a lymph node-negative PM patient. In 1 model scenario, the probability of complications per breast cancer detected was 9-fold greater with the SLND strategy than with the directed ALND strategy (2.7 vs 0.3). The complication rates for the 2 strategies become equivalent in the model scenario when the prevalence of occult invasive cancer was projected to 28%.

CONCLUSIONS

Routine SLND for patients undergoing PM is not warranted given the large number of procedures required to benefit 1 patient and the potential complications associated with performing SLND in all patients.