Prediction of non-sentinel lymph node status in breast cancer with a micrometastatic sentinel node

BACKGROUND: Axillary lymph node dissection (ALND) may not be necessary in women with breast cancer who have micrometastasis in a sentinel node (SN), owing to the low risk of non-SN (NSN) involvement. The aim of this study was to identify a subgroup of women with a micrometastatic SN and a negligible risk of positive NSNs in whom ALND may be avoided. METHODS: Some 237 of 241 women with a macrometastatic SN and 122 of 138 with a micrometastatic SN underwent completion ALND and were compared with respect to NSN involvement. The 122 patients with SN micrometastasis were further analysed to determine factors that could predict the risk of positive NSNs. RESULTS: A total of 121 (51.1 per cent) of 237 women with SN macrometastasis had positive NSNs compared with 22 (18.0 per cent) of 122 with SN micrometastasis (P < 0.001). Multivariate analysis showed that size of SN micrometastasis (odds ratio 3.49 (95 per cent confidence interval (c.i.) 1.32 to 9.23); P = 0.012) and presence of lymphovascular invasion (odds ratio 0.23 (95 per cent c.i. 0.05 to 1.00); P = 0.050) were significantly associated with positive NSNs. SN micrometastasis less than 0.5 mm in diameter combined with absence of lymphovascular invasion was associated with an 8.5 per cent risk of NSN involvement. CONCLUSION: Size of micrometastasis and presence of lymphovascular invasion were significantly related to the risk of finding additional positive axillary lymph nodes when the SN contained only micrometastasis.     

A Simple Risk Score to Predict the Presence of Non-Sentinel Lymph Node Metastases in Breast Cancer Patients with a Positive Sentinel Node

Background

Historically, completion axillary lymph node dissection (cALND) is recommended in sentinel lymph node (SLN)-positive patients. However, the high rate of negative non-sentinel nodes (NSNs) in cALND and the reported low axillary recurrence rates have led to a more conservative approach. A risk score was developed to identify a patient’s individual risk for NSN metastases.

Methods

Data of 182 SLN-positive patients who underwent cALND were used for risk score development. The risk score, consisting of pathological tumor size (≤20/>20 mm), lymphovascular invasion (no/yes), extracapsular extension (no/yes), size of metastases (≤2/>2 mm), and number of positive SLNs (1/>1), was subsequently validated on an external population (n = 180).

Results

The area under the receiver operating characteristic curve was 0.78 (95 % CI 0.71–0.85) in the original population and 0.78 (95 % CI 0.70–0.85) in the validation population. Based on the predicted risk for positive NSNs, three groups were defined: low risk (≤20 %), intermediate risk (21–50 %), and high risk (>50 %). In total, 88 patients met the Z0011 inclusion criteria and none of them had a high predicted risk. Of the 199 non-Z0011 patients, 67 (33.7 %) had low risk, 96 (48.2 %) had intermediate risk, and 36 (18.1 %) had high risk.

Conclusion

A simple risk score, integrating just five clinicopathological variables, was developed that may assist in individual decision making regarding ALND in SLN-positive patients outside of the Z0011 trial.     

Sentinel Node Metastasis in Patients with Breast Carcinoma Accurately Predicts Immunohistochemically Detectable Nonsentinel Node Metastasis

Background: Sentinel lymphadenectomy is highly accurate for identifying axillary metastasis from a primary breast carcinoma. Nonsentinel axillary lymph nodes (NSNs) are unlikely to contain tumor cells if the axillary sentinel node (SN) is tumor free. We previously showed that the size of the primary tumor and the size of its SN metastasis predict the risk of NSN tumor involvement detected by hematoxylin and eosin staining. This study used immunohistochemical staining (IHC) to determine the likelihood of NSN axillary metastasis in the presence of SN metastasis.Methods: Between 1991 and 1997, axillary lymphadenectomy was performed in 156 women (157 axillary basins) who had primary breast carcinoma with SN metastasis. By hematoxylin and eosin staining, we identified NSN metastasis in 55 axillae (35%). IHC was then used to re-examine all NSNs (1827 lymph nodes) from the remaining 102 axillae. The incidence of IHC-detected NSN involvement was analyzed with respect to clinical and tumor characteristics.Results: By using IHC, we identified NSN metastasis in 15 (14.7%) of the 102 axillae. By multivariate analysis, the size of the SN metastasis (P = .0001) and the size of the primary tumor (P = .038) were the only independent variables predicting NSN metastasis determined by using either hematoxylin and eosin staining or IHC. Only the number of SN metastases (1 vs. >1) was a significant (P = .04) predictor of IHC-detected NSN metastasis.Conclusions: Use of IHC increases the likelihood of detection of NSN metastasis, and the risk of IHC-detected metastasis increases with the size of the SN metastasis and the size of the primary tumor. If SN involvement is micrometastatic (2 mm) or detected by using IHC, tumor cells are unlikely to be found in other axillary lymph nodes in patients with a small primary tumor. The clinical significance of micrometastatic disease in lymph nodes is controversial, and a prospective randomized study is necessary to resolve this important issue.Presented at the 52nd Annual Meeting of the Society of Surgical Oncology, Orlando, FL, March 4–7, 1999.     

Axillary Dissection Can Be Avoided in the Majority of Clinically Node-Negative Patients Undergoing Breast-Conserving Therapy

Background

The extent to which ACOSOG Z0011 findings are applicable to patients undergoing breast-conserving therapy (BCT) is uncertain. We prospectively assessed how often axillary dissection (ALND) was avoided in an unselected, consecutive patient cohort meeting Z0011 eligibility criteria and whether subgroups requiring ALND could be identified preoperatively.

Methods

Patients with cT1,2cN0 breast cancer undergoing BCT were managed without ALND for metastases in <3 sentinel nodes (SNs) and no gross extracapsular extension (ECE). Patients with and without indications for ALND were compared using Fisher’s exact and Wilcoxon rank sum tests.

Results

From August 2010 to November 2012, 2,157 invasive cancer patients had BCT. A total of 380 had histologic nodal metastasis; 93 did not meet Z0011 criteria. Of 287 with ≥1 H&E-positive SN (209 macrometastases), 242 (84 %) had indications for SN only. ALND was indicated in 45 for ≥3 positive SNs (n = 29) or ECE (n = 16). The median number of SNs removed in the SN group was 3 versus 5 in the ALND group (p < 0.0001). Age, hormone receptor and HER2 status, and grade did not differ between groups; tumors were larger in the ALND group (p < 0.0001). Of ALND patients, 72 % had additional positive nodes (median = 1; range 1–19). No axillary recurrences have occurred (median follow-up, 13 months).

Conclusions

ALND was avoided in 84 % of a consecutive series of patients having BCT, suggesting that most patients meeting ACOSOG Z0011 eligibility have a low axillary tumor burden. Age, ER, and HER2 status were not predictive of ALND, and the criteria used for ALND (≥3 SNs, ECE) reliably identified patients at high risk for residual axillary disease.     

The impact of the American College of Surgeons Oncology Group (ACOSOG) Z0011 trial: An institutional review

BackgroundAxillary dissection (AD) was historically recommended for all patients with breast tumor involvement discovered by sentinel lymph node biopsy (+SLNB). However, after the ACOSOG Z0011 trial, omission of AD became the recommendation for selected patients with a +SLNB. We report the impact of ACOSOG Z0011 on the completion AD rate in patients with +SLNB at our institution.MethodsWe retrospectively reviewed all patients diagnosed with breast cancer between March 2009 and February 2013 (n = 1781). This cohort was divided into two groups: 1) those diagnosed BEFORE Z0011 and 2) those diagnosed AFTER Z0011. We calculated both the percentage of patients with a +SNLB who underwent AD and, from those patients, the percentage who did and did not meet the Z0011 criteria.ResultsThe BEFORE group contained 849 patients; 144 had +SLNB and from those 113 underwent AD. The AFTER group contained 932 patients: 139 had +SLNB and from those 73 underwent AD. The completion AD rate in the BEFORE group was 78.5%, compared to 52.5% in the AFTER group (p < 0.001). From the patients who met the Z0011 criteria, 75.6% of the BEFORE patients underwent AD, compared to only 2.2%% in the AFTER group (p < 0.001). Among those who did not meet the Z0011 criteria, a similar percentage of patients underwent AD in each group (BEFORE 79.8%, AFTER 74.4%, p = 0.384).ConclusionFollowing the publication of the ACOSOG Z0011 trial, we experienced a significant decrease in the completion AD rate among patients with a +SLNB who met the Z0011 inclusion criteria.     

A decision aid for predicting non-sentinel node involvement in women with breast cancer and at least one positive sentinel node

BACKGROUND: Several clinical trials are re-evaluating the management of the axilla after sentinel node (SN) biopsy. Approximately 50-70% of patients with positive SN have no further nodal involvement. Estimates of the risk of non-sentinel node (NSN) involvement would aid decisions regarding further axillary surgery. METHODS: Clinical and pathological variables for 82 breast cancer patients with metastasis to at least one SN, were used to find independent predictors of the status of NSNs. RESULTS: NSN metastases were found in 46.3% of patients. In a regression model patient age, proportion of SN replaced by metastasis and number of SNs were independent predictors of NSN status. CONCLUSION: Data available after SN biopsy allow estimation of the risk of NSN metastases among patients with positive SNs. Individualised estimates of the risk of NSN involvement may facilitate discussions regarding the trade off between the likely benefits of further axillary surgery and the morbidity of this procedure.     

Changes in utilization of axillary dissection in women with invasive breast cancer and sentinel node metastasis after the ACOSOG Z0011 trial

The American College of Surgeons Oncology Group Z0011 (ACOSOG Z0011) trial demonstrated no survival advantage for women with clinical T1–T2 invasive breast cancer with 1–2 positive sentinel lymph nodes (SLN) who received whole-breast radiation, and no further axillary surgery when compared to women who did undergo axillary lymph node dissection (ALND). We used the National Cancer Database (NCDB) to study changes in utilization of ALND after the publication of this trial. NCDB was queried for female patients from 2012 to 2015 who met Z0011 criteria. Patients were divided into four groups based on Commission on Cancer facility accreditation. Outcome measures include the rate of ALND (nonadherence to Z0011) and the average number of nodes retrieved with ALND. 27,635 patients were identified, with no significant differences in T stage and receptor profiles between groups. Overall rate of ALND decreased from 34.0% in 2012 to 22.7% in 2015. Nonadherence was lowest in Academic Programs (decreasing from 30.1% in 2012 to 20.5% in 2015) and was highest in Community Cancer Programs (41.2% in 2012 to 29.1% in 2015). Median number of positive SLN did not differ between groups (p = .563). Median number of nodes retrieved on ALND decreased from 9 (IQR 5–14) in 2012 to 7 (IQR 4–12) in 2015 (p < .001). In patients who met the ACOSOG Z11 trial guidelines, rates of ALND have decreased over time. However, rates of nonadherence to Z0011 are significantly higher in Community Cancer Programs compared to Academic Programs.     

Management of Early Node‐Positive Breast Cancer in Australia: A Multicentre Study

To examine practice patterns for breast cancer patients with limited sentinel node (SN) disease in light of the ACOSOG Z0011 results. Retrospective analysis of patients with T1‐2 breast cancer and positive sentinel lymph node biopsy (SLNB) admitted between January 2009 and December 2012. Patient demographics, tumor characteristics, and treatments were recorded. Eight hundred positive SLNBs were identified. A total of 452 (56.5%) proceeded to completion axillary lymph node dissection (cALND). cALND rate decreased from 65.1% to 49.7% from 2009–2010 to 2011–2012. cALND was performed for micrometastasis or isolated tumor cells in 39.3% in 2009–2010 and 22.2% in 2011–2012, whereas for macrometastases the rates were 83.1% and 68.6%, respectively. cALND rates diminished for both Z0011‐eligible and ‐ineligible patients. The ACOSOG Z0011 trial presentation and publication coincided with a reduction in cALND for breast cancer with limited nodal disease. There appears equipoise regarding management of macrometastatic SN disease.     

Impact of the American College of Surgeons Oncology Group (ACOSOG) Z0011 trial on Clinical Management of the Axilla in Older Breast Cancer Patients: A SEER-Medicare Analysis

Background

American College of Surgeons Oncology Group (ACOSOG) Z0011 demonstrated that eligible breast cancer patients with positive sentinel lymph nodes (SLN) could be spared an axillary lymph node dissection (ALND) without sacrificing survival or local control. Although heralded as a “practice-changing trial,” some argue that the stringent inclusion criteria limit the trial’s clinical significance. The objective was to assess the potential impact of ACOSOG Z0011 on axillary surgical management of Medicare patients and examine current practice patterns.

Methods

Medicare beneficiaries aged ≥66 years with nonmetastatic invasive breast cancer diagnosed from 2001 to 2007 were identified from the Surveillance, Epidemiology and End Results-Medicare database (n = 59,431). Eligibility for ACOSOG Z0011 was determined: SLN mapping, tumor <5 cm, no neoadjuvant treatment, breast conservation; number of positive nodes was determined. Actual surgical axillary management for eligible patients was assessed.

Results

Twelve percent (6,942/59,431) underwent SLN mapping and were node positive. Overall, 2,637 patients (4.4 % (2,637/59,431) of the total cohort, but 38 % (2,637/6,942) of patients with SLN mapping and positive nodes) met inclusion criteria for ACOSOG Z0011, had 1 or 2 positive lymph nodes, and could have been spared an ALND. Of these 2,637 patients, 46 % received a completion ALND and 54 % received only SLN biopsy.

Conclusions

Widespread implementation of ACOSOG Z0011 trial results could potentially spare 38 % of older breast cancer patients who undergo SLN mapping with positive lymph nodes an ALND. However, 54 % of these patients are already managed with SLN biopsy alone, lessening the impact of this trial on clinical practice in older breast cancer patients.     

Are the ACOSOG Z0011 Trial Findings Being Applied to Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy?

In 2010, the ACOSOG Z0011 trial showed equivalent survival and recurrence between sentinel lymph node biopsy (SLNB) alone versus axillary lymph node dissection (ALND) for those with a tumor positive sentinel node (SN). We examined national trends in axillary surgery following neoadjuvant chemotherapy (NAC) for clinically node positive disease in the years prior to and after the Z0011 trial publication. 12,063 women with cT1‐4N1M0 invasive breast cancer who underwent NAC from 2006 to 2013 and had 1‐3 positive nodes on pathology were selected from the National Cancer Data Base. We defined SLNB as 1–4 nodes and ALND as ≥10 nodes examined. 2,704 women (22.4%) underwent SLNB alone and 9,359 (77.6%) underwent ALND. The rate of SLNB increased from 25.6% in 2006 to 33.3% in 2012 in patients that underwent lumpectomy (p < 0.01) and increased from 20.6% to 22.8% in patients that underwent mastectomy (p = 0.25). Patients treated at Community centers (30.4% versus 19.2% at Academic centers) and those with less positive nodes (32.2% for 1 positive node versus 10.1% for 3 positive nodes, p < 0.01) were more likely to have SLNB alone compared to ALND. On multivariate analysis, treatment with lumpectomy (OR 1.46, CI 1.28–1.67), lower number of positive nodes (OR 3.98, CI 3.29–4.82) and lobular subtype (OR 1.82, CI 1.42–2.34) were independent predictors of receiving SLNB alone after NAC. Approximately 22% of patients with cN1 breast cancer underwent SLNB alone for pN1 disease after NAC. Ongoing clinical trials will determine if recurrence and survival rates are equivalent between SLNB and ALND groups.     

Does the false-negative rate for 1 or 2 negative sentinel nodes after neo-adjuvant chemotherapy translate into a high local recurrence rate?

Prospective trials demonstrate that sentinel node (SN) biopsy after neo-adjuvant chemotherapy (NACT) has a significant false-negative rate (FNR) when only 1 or 2 SNs are removed. It is unknown whether this increased FNR correlates with an elevated risk of recurrence. Tumor Registry data at an NCI-Designated Comprehensive Cancer Center were reviewed from 2004 to 2018 for patients having a negative SN biopsy after NACT. Among 190 patients with histologically negative nodes after NACT having 1 (n = 42), 2 (n = 46), and ≥3 (n = 102) SNs, axillary recurrences occurred in 7.14%, 0%, and 1.96% (p = 0.09), breast recurrences occurred in 2.38%, 6.52%, and 0.98% (p = 0.12), and distance recurrences occurred in 16.67%, 8.70%, and 7.84% (p = 0.27), respectively. Time to first recurrence did not differ by SN count (p = 0.41). After adjustment for age, race, clinical stage, and receptor status, there were no differences in the rates of axillary (p = 0.26), breast (p = 0.44), or distance recurrence (p = 0.24) by numbers of SNs harvested. Median follow-up was 46.8 months. Despite higher post-NACT FNRs reported in randomized trials for patients having <3 sentinel nodes, recurrence rates were not significantly different for 1 versus 2 versus ≥3 SNs. This suggests that patients having 1 or 2 post-NACT SNs identified may not necessitate axillary dissection.     

Sentinel Node Positive Melanoma Patients: Prediction and Prognostic Significance of Nonsentinel Node Metastases and Development of a Survival Tree Model

Background  

Completion lymph node dissection (CLND) following positive sentinel node biopsy (SNB) for melanoma detects additional nonsentinel node (NSN) metastases in approximately 20% of cases. This study aimed to establish whether NSN status can be predicted, to determine its effect on survival, and to develop survival tree models for the sentinel node (SN) positive population.     

Axillary management based on American college of surgeons oncology group Z0011 criteria makes it possible to omit intraoperative diagnosis of sentinel lymph nodes in early breast cancer patients

The ACOSOG Z0011 trial has resulted in the omission of axillary lymph node dissection (ALND) in early breast cancer patients with one or two metastatic sentinel lymph nodes (SLNs). There has been increasing interest in the necessity of intraoperative assessment of SLNs in patients treated based on the Z0011 criteria. We evaluated the utility of intraoperative assessment in these eligible patients. A total of 1396 patients were treated following the Z0011 criteria from April 2012 to December 2019. We examined the proportion and clinicopathological features of patients who underwent ALND due to three or more metastatic SLNs and the sensitivity of intraoperative assessment. Only 16 (1.1%) patients had three or more metastatic SLNs diagnosed by intraoperative assessment, and they immediately underwent ALND. Of the clinicopathological factors, high clinical tumor stage (p = 0.002) and high Ki-67 labeling index value (p = 0.056) were more likely to be associated with the presence of three or more metastatic SLNs. The major independent risk factor for three or more metastatic SLNs was high clinical tumor stage (OR 3.94 [95% CI 1.42–11.0]; p = 0.009). Intraoperative assessment had low sensitivity (70.5%) and a high false-negative rate (29.5%) in detecting SLN metastases. The main finding of our study was the small proportion of patients who required ALND due to three or more metastatic SLNs according to the Z0011 criteria. The Z0011 strategy enables intraoperative assessment of SLNs to be omitted in early breast cancer patients.     

Limits of Day-Before Lymphoscintigraphy to Localize Sentinel Nodes in Women with Cervical Cancer

Background  Lymph node status in cervical cancer is a major prognostic factor. Sentinel lymph node (SN) biopsy using radiocolloid and blue dye labeling and preoperative lymphoscintigraphy has emerged as a potential alternative to systematic lymphadenectomy. The aim of this study was to evaluate the contribution of preoperative lymphoscintigraphy to SN biopsy. Methods  Between April 2001 and December 2005, 71 of 77 patients with cervical cancer (38 patients with stages IA or IB1, and 39 patients with stage IB2, IIA or IIB) underwent laparoscopic SN procedure using radiocolloid and blue dye with day-before lymphoscintigraphy. The SN identification rates and false-negative rates were studied. Results  Seventy patients underwent a combined technique and the last patient a radiocolloid technique alone due to blue dye allergic reaction. Detection rate of lymphoscintigraphy was 84.5% (60/71), with 1.4 sentinel nodes per patient. Three of 11 patients (27.3%) with no SN on lymphoscintigraphy had at least one SN during surgery. Sixteen of 27 patients (59.3%) with solitary SN on lymphoscintigraphy had multiple SNs. Nine of 35 patients (25.7%) with unilateral SNs on lymphoscintigraphy had bilateral SNs at surgery (kappa = 0.44 [0.19–0.64]). When categorized into <2 and ≥2 sentinel nodes, the correlation between lymphoscintigraphic and surgical detection was poor (kappa = 0.05 [0.0–0.18]). Conclusions  SN biopsy is a feasible and accurate method to stage early cervical cancer. However, day-before lymphoscintigraphy is poorly correlated to surgical SN mapping.     

Lymph Node Tumor Volumes in Patients Undergoing Sentinel Lymph Node Biopsy for Cutaneous Melanoma

Background: Regional lymph node tumor volumes in patients undergoing sentinel lymph node (SN) biopsy (SNB) for treatment of cutaneous melanoma have not been described. The objectives of this study were to describe the lymph node tumor volumes typically seen in this population and to correlate tumor volumes with tumor thickness and positive SN characteristics.Methods: Review of a consecutive series of patients with clinically localized cutaneous melanoma who underwent SNB of nonpalpable regional lymph node basins followed by complete lymphadenectomy (LND) was performed. Multiple lymph node sections from positive SNs and nonsentinel nodes (NSNs) in LND specimens were examined microscopically. Individual tumor deposit diameters were measured using an ocular micrometer. Aggregate tumor volumes were calculated for SN and LND specimens. Tumor volumes and SN and LND positivity rates were correlated with tumor thickness, the number of positive SNs, and the presence of multiple SN tumor deposits.Results: SNB procedures were performed for 149 melanomas in 189 regional nodal basins. The mean tumor depth was 2.48 mm. The mean number of SNs/basin was 2.1. Thirty-two of 149 SNB procedures (21.5%) revealed a total of 34 nodal basins with at least one positive SN. The median tumor volume in positive SNs was 4.7 mm³ (range, 0.1-3618 mm³; mean, 209 mm³). The median aggregate tumor volume in positive LND specimens was 4.9 mm³ (range, 0.1-3618 mm³; mean, 224 mm³). Six basins (17.6%) contained at least one positive NSN. The regional node aggregate tumor volume correlated weakly with tumor thickness (Pearsons correlation coefficient = .302, P = .0934). NSN positivity was not predicted by tumor thickness, American Joint Committee on Cancer tumor stage, number of positive SNs, or number of metastatic deposits within SNs.Conclusions: Most melanoma-positive SNs contain minute tumor volumes. Tumor thickness and patterns of SN metastases may not be predictive of tumor burden or the presence of positive NSNs.     

Healthcare Costs Reduced After Incorporating the Results of the American College of Surgeons Oncology Group Z0011 Trial into Clinical Practice

The purpose of our study was to quantitate the changes in axillary lymph node dissection (ALND), frozen section (FS), and the impact on costs after the publication of the American College of Surgeons Oncology Group (ACOSOG) Z0011 trial. We compared axillary nodal management and cost data in breast cancer patients who met Z0011 criteria and were treated with lumpectomy and sentinel lymph nodes (SLN) biopsy from 2007 to July 2013. Of 800 patients, 67 (13.5%) and 34 (12.5%) patients in the pre‐ and post‐Z0011 era had 1–2 positive SLN. ALND decreased from 78% to 21% (p < 0.001) after publication of Z0011. The mean overall cost of SLN biopsy was $41,059 per patient, while SLN biopsy with completion ALND was $50,999 (p < 0.001). Intraoperative FS use decreased from 95% to 66% (p = 0.015). Omitting the FS decreased mean costs from $4,319 to $2,036. The application of Z0011 resulted in an overall mean cost savings of $571,653 from 2011 to July 2013. ACOSOG Z0011 significantly impacted axillary management resulting in a 20% reduction in the mean overall cost per patient by omitting ALND. In these patients, intraoperative FS analysis had poor sensitivity (56%) and doubled the cost of pathologic examination. Fewer ALND and intraoperative FS were performed after the publication of ACOSOG Z0011. Eliminating FS and ALND in patients who met Z0011 criteria, results in significant cost savings.     

Predicting the status of the nonsentinel axillary nodes: a multicenter study

BACKGROUND: Sentinel lymph node (SLN) biopsy is a minimally invasive procedure that provides accurate nodal staging information. The need for completion axillary dissection after finding a positive SLN for breast cancer has been questioned. HYPOTHESIS: The presence of nonsentinel node (NSN) metastases in the axillary dissection specimen correlates with tumor size, the number of SLNs removed, and the number of positive SLNs. DESIGN: Prospective, multi-institutional study. PARTICIPANTS AND METHODS: The University of Louisville Breast Cancer Sentinel Lymph Node Study is a nationwide study involving 148 surgeons. All patients underwent SLN biopsy, followed by level I/II axillary dissection. All SLNs were evaluated histologically at a minimum of 2-mm intervals. Immunohistochemical analysis using antibodies for cytokeratin was performed at the discretion of each participating institution. All NSNs were evaluated by routine histologic examination. RESULTS: An SLN was identified in 1268 (90%) of 1415 patients. Increasing tumor size was significantly correlated with increasing likelihood of positive NSNs: T1a, 14%; T1b, 22%; T1c, 30%; T2, 45%; and T3, 57% (P =.002, chi(2) test). The presence of positive NSNs was not significantly associated with the number of SLNs removed. Patients with more than 1 positive SLN were more likely to have positive NSNs than those with only 1 positive SLN (50% vs 32%; P<.001, chi(2) test). Increasing tumor size and the presence of multiple positive SLNs were also associated with the presence 4 or more positive axillary nodes. Multivariate analysis confirmed that tumor size and the number of positive SLNs were independent factors predicting the presence of positive NSNs. CONCLUSIONS: The likelihood of positive NSNs correlates with increasing tumor size and the presence of multiple positive SLNs. However, even patients with small primary tumors have a substantial risk of residual axillary nodal disease after SLN biopsy. These data will be helpful in counseling patients regarding the need for completion axillary dissection after a positive SLN is identified.     

Patients with sentinel lymph node positive melanoma: Who needs completion lymph node dissection?

Introduction

Completion lymph node dissection (CLND) for melanoma after positive sentinel lymph node biopsy (SLNB) was recently shown to improve regional but not overall survival, likely due to the majority of patients harboring no further nodal disease. We sought to determine predictors of non-sentinel node (NSN) positivity.

Selective Modulation of Paracortical Dendritic Cells and T-Lymphocytes in Breast Cancer Sentinel Lymph Nodes

Sentinel nodes (SNs), the nodes nearest a primary tumor on the direct lymphatic drainage path, are the site of earliest metastases, and in melanoma show striking immune modulation. We evaluated SNs from breast cancer patients for evidence of similar immune perturbation. The purpose of this study was to evaluate whether SNs from patients with breast cancer show the alterations in the histology and cytology of the paracortical areas seen in SNs from patients with melanoma. Formalin-fixed and paraffin-embedded sections from 32 SNs and 32 nonsentinel nodes (NSNs) from patients with breast cancer were evaluated. Sections were stained with hematoxylin and eosin and with antibodies to S-100 protein and HLA-DR, DQ, and DP to identify interdigitating dendritic cells (IDCs), and by an antibody to CD43RA to delineate T lymphocytes. By computerized image analysis we evaluated the distribution, frequency, immunophenotype, and activation status of IDCs and associated T lymphocytes in SNs and NSNs. Average areas occupied by S-100-positive dendritic cells (DCs) in SNs and NSNs were 0.13% and 19.98%, respectively, of total nodal area (p < 0.0001). The average density of S-100-positive IDCs in SNs was 11.00/mm2 and in NSNs was 257.88/mm2 (p < 0.0001). In SNs 43.55% of DCs (4.93/mm2) were nondendritic, 51.92% (5.69/mm2) had short dendrites, and 5.2% were mature with long dendrites (0.62/mm2). In SNs the ratio of immature to mature IDCs was 7.95:1. In NSNs, 8.09% of DCs (8.5/mm2) were nondendritic, 28.22% (67.46/mm2) had short dendrites, and 63.07% (145.96/mm2) were mature DCs with long dendrites. The ratio of immature to mature DCs in NSNs was 1:6.66. The average areas occupied by HLA class II-positive DCs in SNs and NSNs were 4.21% and 31.82%, respectively, of total nodal area. The frequency of coexpression of S-100 and HLA class II by immature IDCs without dendrites was 11.27% in SNs and 15.00% in NSNs. In both SNs and NSNs (p < 0.001) all mature S-100-positive IDCs with long dendrites expressed HLA class II. CD43RA-positive T lymphocytes occupied 20.06% of total nodal area in SNs and 63.57% in NSNs (p < 0.0001). The SNs from breast cancer patients are profoundly immune modulated with, by comparison to NSNs, markedly reduced paracortical areas, densities of paracortical DCs, frequency of S-100-positive IDCs coexpressing HLA class II, and a predominance of immature nondendritic and poorly dendritic DCs.