Detailed evaluation of one step nucleic acid (OSNA) molecular assay for intra-operative diagnosis of sentinel lymph node metastasis and prediction of non-sentinel nodal involvement: Experience from a London Teaching Hospital

One step nucleic acid (OSNA) is a molecular diagnostic assay for intra-operative detection of sentinel node metastases. This study compared OSNA with standard histopathology in 283 nodes from 170 patients to evaluate sensitivity, specificity and concordance of the two methods. Additional analysis was done to investigate how cytokeratin 19 mRNA copy number affects prediction of non-sentinel node positivity. OSNA sensitivity was 93.2% and specificity 95.8%. Concordance between OSNA and histology was 95.6%. In the patients who had axillary clearance, the OSNA mRNA copy number on the sentinel node had 100% negative predictive value for histologically proven metastasis. mRNA copy numbers <1400 were not associated with histologically proven metastasis in subsequent nodes at axillary clearance. OSNA is a reliable method for the intra-operative evaluation of axillary lymph node metastasis even when half of the lymph node is used. Identification of mRNA copy number threshold predicting the positivity of non-sentinel axillary nodes seems to be feasible and would be clinically important.     

Axillary lymphectomy in breast cancer

BACKGROUND: The aim of the study was to demonstrate the prognostic value of sentinel node biopsy compared to the sampling of clinically suspected nodes and lymphectomy of the 3 axillary levels. METHODS. From October 1996 to January 1999, 60 patients with breast cancer with a diameter of 4 cm or under using different procedures of axillary lymphadenectomy. Sentinel node biopsy was performed using Giuliano's technique, followed by lymph nodes larger than 5 cm (lymph node sampling) and lastly all axillary lymph nodes (axillary lymphectomy at 3 levels). RESULTS: Sentinel nodes were identified in all patients and a mean of 3 sentinel nodes (range 1-5) were removed during the procedure. Histological analysis showed metastatic sentinel nodes in 21 cases. Lymph node sampling was possible in 43 patients who presented enlarged nodes. The mean number of lymph nodes removed was 6 (range 3-10). Lymph node metastasis was found in 10 patients and of these 7 had a metastatic sentinel node, whereas 3 had presented negative results. Histological tests in all 60 cases of complete axillary lymphectomy showed positive results in 4 cases confirming metastasis present in sentinel nodes. CONCLUSIONS: The results show that the association of lymph node sampling can improve the efficacy of sentinel node dissection, highlighting the rare cases of false negatives. In our study, total axillary lymphectomy did not add any information to the N parameter and was resolutive in a small percentage of cases.     

Can one stop nucleic acid sampling (OSNA) predict nodal positivity following neoadjuvant chemotherapy? A prospective cohort study of 293 patients

Until recently, axillary node clearance had long been the standard of care in patients with axillary node-positive disease. One stop nucleic acid sampling (OSNA) has been used to guide intraoperative decision-making regarding suitability for axillary node clearance (ANC). The aim of this study is to evaluate the use of OSNA following neoadjuvant chemotherapy (NACT) and whether it can predict lymph node burden in ANC. A single center, prospective cohort study was performed on 297 patients having OSNA between 2016 and 2019. Patients were sub-classified according to node positivity at diagnosis and those treated with NACT and outcomes included copy number and lymph node harvest. Axillary complete pathological response was observed in 24/36 patients (67%) following NACT. 14/16 patients (87%) having axillary node clearance had axillary node disease limited to 4 nodes. OSNA copy numbers were significantly higher in patients showing disease progression following NACT. Overall, 73% of patients with lymph node positivity at diagnosis could be successfully treated with a combination of NACT and lymph node excision of four nodes. De-escalating axillary surgical treatment to resection of four nodes following NACT may be effective in balancing oncological resection and limiting treatment morbidity. ONSA can correctly identify patients experiencing disease progression who would benefit from traditional three-level ANC.     

Quadrantectomy and removal of the sentinel lymph node under local anaesthesia in the day hospital setting

In recent years, breast carcinoma diagnostics and therapy have evolved very considerably, allowing conservative surgery in most cases. These kinds of major operations have been greatly simplified since the introduction of the sentinel lymph node approach, with the possibility of a day surgery operation under local anaesthesia. The aim of this study, after thorough analysis of the axillary lymph nodes with ultrasound and cytological examinations, was to assess whether it would be possible to distinguish between negative and metastatic lymph nodes and whether the operation could be performed under local anaesthesia without hospitalisation. From January 2005 to January 2007, 54 breast carcinoma patients with negative axillary lymph nodes (after ultrasound examination) had a quadrantectomy and sentinel lymph node removal under local anaesthesia together with sedation where appropriate. Eight patients who presented micrometastases or isolated tumour cells in the sentinel lymph node underwent a subsequent lymphadenectomy. Our data show that, thanks to thorough analysis of the axillary cavity, it may be possible to use the sentinel lymph node approach with a good chance of the patient remaining free of distant metastases and of operating under local anaesthesia.     

Removal of two sentinel nodes accurately stages the axilla in breast cancer

BACKGROUND: Assessment of lymph node status in breast cancer is still necessary for staging. Sentinel lymph node biopsy (SNB) may provide accurate staging with less morbidity than axillary clearance. The aim of this study was to assess the effect of the number of sentinel nodes removed on the false-negative rate. METHODS: Data were collected prospectively from 395 women undergoing SNB for breast cancer, between June 1995 and December 2001. All nodes that were hot and/or blue were removed and analysed. RESULTS: During this interval 136 patients who had SNB were lymph node positive. The median number of sentinel nodes removed was two (range one to five). The overall false-negative rate of SNB in these women was 7.1 per cent. If only one sentinel node had been removed, the false-negative rate would have been 16.5 per cent. The removal of more than two nodes had no effect on axillary staging in all but two women. CONCLUSION: In early breast cancer, when there were multiple sentinel nodes, removal of two sentinel nodes significantly reduced the false-negative rate compared with removal of one node. Removing more than two sentinel nodes did not significantly reduce the false-negative rate further.     

Role of axillary node dissection in patients with T1a and T1b breast cancer: Mayo Clinic experience.

HYPOTHESIS: The incidence of nodal positivity in patients with early breast cancer is low, and axillary lymph node dissection may not be justified in all such patients. DESIGN: Retrospective case series. SETTING: Tertiary institution. PATIENTS: All patients with T1a and T1b breast cancer who had both primary breast surgery and axillary lymph node dissection at Mayo Clinic in Jacksonville, Fla, from January 1, 1992, through February 28, 1998. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Tumor size and biological grade, estrogen and progesterone receptor status, number of nodes harvested, and number of nodes positive for disease. RESULTS: Of 163 patients studied, 39 had T1a and 124 had T1b tumors. Node positivity was 0% for T1a and 11.3% for T1b tumors (P =.03). Lymph node involvement and estrogen receptor status were not related (P =.29). However, the risk of lymph node positivity for progesterone receptor-negative (P =.01) and estrogen receptor-negative/progesterone receptor-negative tumors was significantly higher than for progesterone and estrogen/progesterone receptor-positive tumors (P =.04). Furthermore, the risk of lymph node positivity was significantly higher as tumor size increased (P =.002). Finally, higher tumor grade conferred a higher risk of lymph node involvement (P =.02). CONCLUSIONS: T1a tumors have minimal risk of nodal positivity and may not require subsequent axillary lymph node dissection in the future. T1b tumors should be managed with routine analysis of axillary lymph node status. Whether sentinel node mapping can change this standard awaits further study.     

Limitation in gamma probe localization of the sentinel node in breast cancer patients with large excisional biopsy

BACKGROUND: Radiolocalization and selective biopsy of the sentinel node to correctly predict the status of remaining lymph nodes may provide an alternative to axillary dissection in selected breast cancer patients with clinically negative lymph nodes. STUDY DESIGN: In a nonrandomized, multicenter clinical trial, gamma probe localization for lymphatic mapping and sentinel node biopsy along with axillary dissection was performed on 75 patients with invasive breast cancer and clinically negative lymph nodes. The accuracy of the sentinel node biopsy to correctly predict the status of the remaining axillary lymph nodes was established through standard pathologic investigation. RESULTS: A sentinel node was identified in 70 of 75 patients with a technical success rate of 93%. Of these 70 patients, 21 (30%) had axillary nodal metastases identified pathologically. Four of these 21 (19%) had sentinel nodes negative for metastases. All 4 false-negative patients had prior excisional biopsies. The false-negative group had a larger mean maximal biopsy dimension than the true-positive group. Eleven of the 21 patients with axillary metastases had a diagnosis made by core needle biopsy with no false negatives. CONCLUSIONS: The accuracy of the sentinel node biopsy in correctly predicting the status of remaining axillary lymph nodes may be limited in patients with large excision before radiolocalization of the sentinel node. Our findings suggest that excisional biopsy should be avoided prior to lymphatic mapping for sentinel node biopsy.     

Multicentre study of ultrasonographically guided axillary node biopsy in patients with breast cancer

BACKGROUND: Axillary lymph node dissection is still performed as a staging procedure since lymph node status is the most important prognostic factor in patients with breast cancer. Sentinel node biopsy may replace routine axillary lymphadenectomy, especially in patients with small breast cancers. This study investigated whether ultrasonographically guided fine-needle aspiration cytology (FNAC) of the axillary lymph nodes in clinically node-negative patients was an accurate staging procedure to select patients for sentinel node biopsy. METHODS: One hundred and eighty-five consecutive patients were included. All had axillary ultrasonography and detected nodes were categorized according to their dimensions and echo patterns. Ultrasonographically guided FNAC was carried out if technically possible. These results were compared with the results of the sentinel node biopsy and subsequent axillary dissection. RESULTS: In 116 patients no lymph nodes were detected by ultrasonographic imaging. Of 69 patients with visible nodes, 31 had malignant cells on FNAC. There were no false-positive results. Some 87 of 185 patients had axillary metastases on definitive histological examination. Ultrasonography was sensitive in patients with extensive nodal involvement. Failure of the examination was caused by problems learning the method, difficulty in puncturing small lymph nodes and sampling error. CONCLUSION: In patients without palpable axillary nodes, a sentinel node biopsy could be avoided in 17 per cent since ultrasonography combined with FNAC had already diagnosed axillary metastases. The method is particularly valuable in larger breast cancers.     

A multivariate study of the relationship between regional lymph node metastases and prognosis in patients with operable breast cancer

In order to evaluate the prognostic importance of clinical and histological node information, we made univariate and multivariate analyses of regional lymph node metastases in 223 patients with operable breast cancer who were surgically treated from 1973 to 1985. Clinical axillary node status, histological involvement of the axillary lymph nodes, their anatomical levels and numbers, and histological involvement of the internal mammary lymph nodes were selected as evaluating prognostic factors. The histological presence or absence of axillary node involvement, especially at the distal level, proved to be the most important prognostic factor. However, neither the anatomical level nor the number of histologically involved axillary lymph nodes appeared to be an important prognostic factor. On the other hand, histological involvement of the internal mammary nodes appeared to be an important and independent prognostic factor. Therefore, we concluded that axillary lymph node dissection with a biopsy of the internal mammary nodes would provide more accurate information about the prognosis of patients with operable breast cancer.     

A multivariate study of the relationship between regional lymph node metastases and prognosis in patients with operable breast cancer.

In order to evaluate the prognostic importance of clinical and histological node information, we made univariate and multivariate analyses of regional lymph node metastases in 223 patients with operable breast cancer who were surgically treated from 1973 to 1985. Clinical axillary node status, histological involvement of the axillary lymph nodes, their anatomical levels and numbers, and histological involvement of the internal mammary lymph nodes were selected as evaluating prognostic factors. The histological presence or absence of axillary node involvement, especially at the distal level, proved to be the most important prognostic factor. However, neither the anatomical level nor the number of histologically involved axillary lymph nodes appeared to be an important prognostic factor. On the other hand, histological involvement of the internal mammary nodes appeared to be an important and independent prognostic factor. Therefore, we concluded that axillary lymph node dissection with a biopsy of the internal mammary nodes would provide more accurate information about the prognosis of patients with operable breast cancer.     

S-Classification of Sentinel Lymph Node Predicts Axillary Nonsentinel Lymph Node Status in Patients with Breast Cancer

Background One-half of breast cancer patients with positive sentinel lymph node (SN) have no further metastases in the axillary lymph node basin. The aim of the present study was to identify patients with positive SN who are unlikely to have further metastases in the axillary lymph node basin, using a new classification of SN, namely the S-classification. Methods Specimens of positive SN were subjected to a pathological review according to the previously published S-classification. S-stages of positive SN were correlated with the status of further metastases in the axillary lymph node basin after axillary lymph node dissection (ALND). Results Of 117 patients who underwent sentinel lymph node biopsy, 36 (30.8%) had a positive SN and were subjected to level I and II ALND. The occurrence of positive nonsentinel nodes was significantly related to the S-stage of SN. No patient with stage SI had additional metastases in the nonsentinel lymph nodes, while 14.3% of patients with SII stage disease and 60.9 % of patients with SIII disease had other non-SN that were metastatic. Conclusion S-stages of positive SN are highly predictive for axillary nonsentinel node status. Especially patients with SI sentinel node metastases appear to be at low risk for further nonsentinel node metastases.     

Non-sentinel lymph node metastases in breast cancer patients with metastatic sentinel nodes

BACKGROUND: Sentinel lymph node biopsy (SLNB) has been shown to be relatively accurate in axillary nodal staging in breast cancer. In more than half of the patients with metastatic sentinel lymph node (SLN), the SLN was the only lymph node involved in the axilla. Methods: A retrospective analysis was performed for those female Chinese breast cancer patients who underwent SLNB. All patients had axillary dissection after SLNB. Those patients with metastatic SLN were selected for analysis. Various tumour factors and SLN factors were analysed to study the association with residual lymph node metastasis. Results: A total of 139 SLNB was performed. The success rate of SLN localization, false negative rate and accuracy were 92%, 9% and 95%, respectively. Fifty-five patients had metastases in the SLN. In 38 patients (69%), SLN was the only lymph node involved in the axilla. Tumours <3 cm, a single metastatic SLN, presence of micro metastases and the absence of extracapsular spread in the SLN were associated with the absence of metastasis in the non-sentinel lymph nodes. Conclusion: Sentinel lymph node biopsy is accurate in the nodal staging of Chinese breast cancer patients. Several factors such as tumour <3 cm, a single metastatic SLN, micro metastases and the absence of extracapsular spread in the sentinel node(s) are useful predictors for the absence of residual disease in the axilla. With further studies and verification, these factors may prove to be important in determining which patients with metastatic SLN will require further axillary treatment. Until such information is available, axillary dissection should be performed when positive sentinel nodes are found.     

Axillary lymph node metastases in patients with a final diagnosis of ductal carcinoma in situ

BACKGROUND: Recent studies report the incidence of axillary metastases in patients with ductal carcinoma in-situ (DCIS) approaches 13%. The purpose of this study was to define the incidence of axillary micrometastases in patients with pure DCIS before and after the introduction of sentinel lymph node biopsy. METHODS: Patients with a final diagnosis of DCIS form the basis of this study. Data were entered prospectively into an Institutional Review Board approved Oracle database from January 1997 through July 2002. RESULTS: One hundred and thirty-four patients had lymph nodes evaluated. Ninety-eight percent of patients had no evidence of metastatic disease and 2% were found to have micrometastases. This was consistent in those who had level I or II lymph node sampling or both and those who had lymphatic mapping and a sentinel lymph node biopsy procedure. CONCLUSIONS: These data do not support axillary lymph node removal of any type in patients with pure DCIS.     

Patterns of axillary nodal involvement in breast cancer. Predictability of level one dissection.

Two hundred consecutive mastectomies with total axillary dissection were analyzed for patterns of involvement at levels one, two and three. The purpose was to determine the accuracy of level one axillary dissection in predicting the status of the entire lymph node chain in carcinoma of the breast. Level one was defined as latissimus dorsi to lateral pectoralis minor; level two behind the pectoralis minor and level three medial pectoralis minor to thoracic inlet. The average number of nodes analyzed per patient was 22. The average number of nodes recovered per level was 14 at level one, 11.5 at level two and eight at level three. One hundred twenty patients (60%) had no nodal involvement, while 80 patients had metastases to axillary lymph nodes. There were seven patients (3.5% of the entire 200) who had positive nodes at levels two and/or three without metastasis to level one. This represents the incidence of "skip" metastases. The group exhibiting "skip" metastases comprise 5.5% of patients (seven of 127) with negative axillary nodes at level one and 8.7% of patients (seven of 80) with axillary metastases secondary to carcinoma of the breast. In the authors' experience, level one lymph node dissection is an accurate predictor of the status of the entire lymph node chain. Negative nodes at level one would indicate lack of involvement at levels two and three with nearly 95% accuracy.     

Sentinel lymph node mapping following neoadjuvant chemotherapy for breast cancer

The purpose of this study was to evaluate the feasibility of sentinel lymph node mapping in patients undergoing neoadjuvant chemotherapy for breast carcinoma prior to lumpectomy or mastectomy and sentinel lymph node mapping followed by complete axillary dissection. A retrospective analysis of 14 patients from February 1998 to July 2000 with stage I to stage IIIB breast cancer diagnosed by core biopsy underwent neoadjuvant chemotherapy (doxorubicin/cyclophosphamide) prior to definitive surgery, including lumpectomy or mastectomy and sentinel lymph node mapping, followed by full axillary dissection. Thirteen of 14 patients had successful sentinel lymph node identification (93%), and all 14 underwent full axillary dissection. An average of 2.2 sentinel nodes and a median of 16 axillary lymph nodes (including sentinel nodes) were found per patient. Of the 13 patients in whom a sentinel lymph node was identified, 10 were positive for metastases (77%). Only 4 of the 10 had further axillary metastases (40%). Three patients had negative sentinel lymph nodes shown by hematoxylin and eosin and cytokeratin stainings and had no axillary metastases (0% false negative). The single patient in whom a sentinel lymph node could not be identified had stage IIIA disease with extensive lymphatic tumor emboli. Sentinel lymph node mapping is feasible in neoadjuvant chemotherapy breast cancer patients and can spare a significant number of patients the morbidity of full axillary dissection. Further study to evaluate sentinel lymph node mapping in this patient population is warranted.     

Practical guidelines for optimal gamma probe detection of sentinel lymph nodes in breast cancer: results of a multi-institutional study. For the University of Louisville Breast Cancer Study Group

INTRODUCTION: Multiple radioactive lymph nodes are often removed during the course of sentinel lymph node (SLN) biopsy for breast cancer when both blue dye and radioactive colloid injection are used. Some of the less radioactive lymph nodes are second echelon nodes, not true SLNs. The purpose of this analysis was to determine whether harvesting these less radioactive nodes, in addition to the "hottest" SLNs, reduces the false-negative rate. METHODS: Patients were enrolled in this multicenter (121 surgeons) prospective, institutional review board-approved study after informed consent was obtained. Patients with clinical stage T1-2, N0, M0 invasive breast cancer were eligible. This analysis includes all patients who underwent axillary SLN biopsy with the use of an injection of both isosulfan blue dye and radioactive colloid. The protocol specified that all blue nodes and all nodes with 10% or more of the ex vivo count of the hottest node should be removed and designated SLNs. All patients underwent completion level I/II axillary dissection. RESULTS: SLNs were identified in 672 of 758 patients (89%). Of the patients with SLNs identified, 403 patients (60%) had more than 1 SLN removed (mean, 1.96 SLN/patient) and 207 patients (31%) had nodal metastases. The use of filtered or unfiltered technetium sulfur colloid had no impact on the number of SLNs identified. Overall, 33% of histologically positive SLNs had no evidence of blue dye staining. Of those patients with multiple SLNs removed, histologically positive SLNs were found in 130 patients. In 15 of these 130 patients (11.5%), the hottest SLN was negative when a less radioactive node was positive for tumor. If only the hottest node had been removed, the false-negative rate would have been 13.0% versus 5.8% when all nodes with 10% or more of the ex vivo count of the hottest node were removed (P =.01). CONCLUSIONS: These data support the policy that all blue nodes and all nodes with 10% or more of the ex vivo count of the hottest SLN should be harvested for optimal nodal staging.     

Ultrasonography and Fine-Needle Aspiration Cytology Can Spare Breast Cancer Patients Unnecessary Sentinel Lymph Node Biopsy

Background Some 30% to 40% of the breast cancer patients scheduled for sentinel node biopsy have axillary metastasis. Pilot studies suggest that ultrasonography is useful in the preoperative detection of such nodes. The aims of this study were to evaluate the sensitivity of preoperative ultrasonography and fine-needle aspiration cytology for detecting axillary metastases and to assess how often sentinel node biopsy could be avoided. Methods Between October 1999 and December 2003, 726 patients with clinically negative lymph nodes were eligible for sentinel node biopsy. A total of 732 axillae were examined. Preoperative ultrasonography with subsequent fine-needle aspiration cytology in case of suspicious lymph nodes was performed in all patients. The sentinel node procedure was omitted in patients with tumor-positive axillary lymph nodes in lieu of axillary lymph node dissection. Results Ultrasound and fine-needle aspiration cytology established axillary metastases in 58 (8%) of the 726 patients. These 58 were 21% of the total of 271 patients who were proven to have axillary metastasis in the end. Of the patients with ultrasonographically suspicious lymph nodes and negative cytology, 31% had tumor-positive sentinel nodes. Patients with preoperatively established metastases by ultrasonography and fine-needle aspiration cytology had more tumor-positive lymph nodes (P < .001) than patients with metastases established later on. Conclusions The sensitivity of ultrasonography and fine-needle aspiration cytology is 21%, and unnecessary sentinel node biopsy is avoided in 8% of the patients. This approach improves the selection of patients eligible for sentinel node biopsy.     

Lymphatic mapping in patients with breast cancer and previous augmentation mammoplasty

Sentinel lymph node biopsy (SLNB) is now an established method of axillary staging in patients with breast cancer. However, the augmented breast poses an interesting challenge to this procedure. We hypothesized that SLNB is feasible in patients with augmented breasts who subsequently develop breast cancer. A retrospective study was performed from 1995 to 2006. Ten patients with augmented breasts underwent breast conservation therapy with SLNB. Sentinel lymph nodes were identified in all 10 patients. Three patients had positive sentinel nodes. Two patients proceeded to axillary lymph node dissection (ALND), and one declined. The subsequent ALND were negative for metastatic cancer. Seven patients had negative sentinel nodes. One patient with a negative sentinel node underwent ALND with all nodes negative for metastasis. Two patients were lost to follow-up. Of the remaining eight patients, the mean duration of follow-up was 71 months. None of these patients had evidence of axillary recurrence or distant metastasis at time of last follow-up. SLNB is a feasible method of axillary node staging in patients who have undergone augmentation mammoplasty who subsequently develop breast cancer. Further studies are needed to better determine the accuracy of lymphatic mapping in this patient population.     

Axillary Lymph Node Recurrence of Papillary Thyroid Microcarcinoma: Report of a Case

We report a case of axillary lymph node recurrence of thyroid papillary microcarcinoma (PMC) in a 51-year-old woman who had undergone thyroidectomy with lymph node dissection 5 years earlier. We performed residual thyroid resection with cervical and bilateral axillary lymph node dissection, and pathological examination revealed well-differentiated papillary carcinoma, with partial poor differentiation. Postoperative radioiodine therapy was ineffective, and the patient died of systemic dissemination of the recurrence 8 months after her second operation. The positive cell rates of proliferating cell nuclear antigen and Ki-67 were clearly higher in the recurrent lymph nodes than in the primary thyroid tumor, suggesting increased cell proliferation in the recurrent lymph nodes. Thyroid papillary carcinoma rarely recurs in the axillary lymph nodes, but its possibility must be kept in mind, especially in patients with remarkable cervical lymph node metastasis and those who undergo extensive lymph node dissection.     

Sentinel node biopsy prior to neoadjuvant chemotherapy

BACKGROUND: Several studies have explored sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy, but false negative rates and the loss of pretreatment nodal staging are limitations. Sentinel lymph node biopsy prior to induction chemotherapy may address both. METHODS: Sentinel lymph node biopsy was performed in clinically node negative patients prior to initiating chemotherapy. Standard level I/II axillary lymph node dissection (ALND) was performed at the time of surgery in those patients who had metastases in the sentinel lymph node (SLN). RESULTS: Twenty-five patients had 26 SLNB prior to the initiation of chemotherapy. The SLN was identified in all cases (100%). Twelve patients (48%) were found to be node negative and did not require axillary node dissection after chemotherapy. Of the patients who were SLN positive and underwent completion ALND, residual nodal disease was identified in 60%. There were no surgical complications or delay of chemotherapy. CONCLUSIONS: Sentinel lymph node biopsy prior to neoadjuvant chemotherapy can avoid the morbidity of ALND without compromising the accuracy of axillary staging. It allows for identification of node positive patients subsequently rendered disease free in the regional nodes, which can assist in planning additional chemotherapy or radiation.