Increased false negative rates in sentinel lymph node biopsies in patients with multi-focal breast cancer

Diffusion-Weighted Imaging of Breast Cancer: Correlation of the Apparent Diffusion Coefficient Value with Pathologic Prognostic Factors

Objective

The aim was to evaluate relationship between apparent diffusion coefficient (ADC) values with pathologic prognostic factors in breast carcinoma (BC).

Materials and Methods

83 patients were enrolled in this study. Prognostic factors included age, tumor size, expression of estrogen receptor (ER) and progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), nuclear grade (NG), lymph node involvement and histologic type. The relationship between ADC and prognostic factors was determined using Independent sample t-test, ANOVA, Pearson correlation and relative operating characteristics (ROC) analysis.

Results

There was no significant difference between ADC and prognostic factors, including age, tumor size, ER, HER2 and histologic type. The PR-positive tumors (p=0.03) and axillary lymph node involvement (p=0.000) showed a significant association with lower ADC values. The ADC values were significantly lower in high-grade tumors than low-grade tumors (p=0.000). ROC analysis showed an optimal ADC threshold of 0.66 (×10-3 mm2/s) for differentiating low-grade tumors from high-grade tumors (sensitivity, 85.5%; specificity, 81%; area under curve, 0.90).

Conclusion

The lower ADC values of BC were significantly associated with positive expression of PR, LN positivity and high-grade tumor. Especially, ADC values were valuable in predicting NG subgroups.

Sentinel lymph node biopsy validation for large tumors

BACKGROUND

Sentinel lymph node biopsy (SLNB) remains under discussion for large size tumors. The aim of this work has been to study the false negative rate (FNR) of SLNB for large tumors and predictive factors of false negative (FN).

MATERIALS AND METHODS

A study of a multicentric cohort, involved patients presenting N0 breast cancer with a SLNB eventually completed by complementary axillary lymph node dissection (cALND). The main criteria were the FNR and the predictive factors of FN.

RESULTS

12.415 patients were included: 748 with tumors ≥30 mm, 1101 with tumors >20 and < 30 mm and 10.566 with tumors ≤20 mm, with a cALND respectively for 501 patients (67%), 523 (62.1%) and 2775 (26.3%). The FNR were respectively: 3.05% (IC95%: 1.3-4.8) for tumors ≥30 mm*, 3.5% (1.8-5.2) for tumors >20 and < 30 mm*, 1.8% (1-2.4) for tumors ≤20 mm (p < 0.05) (*Not significant). At multivariate analysis, SN number harvested ≤2 (OR:2.0, p = 0.023) and tumor size >20 and < 30 mm (OR:2.07, p = 0.017) were significant predictive factors of FN, without significant value for tumor size ≥30 mm (OR:1.83, p = 0.073).

CONCLUSION

The FNR of SLNB was not higher amongst large size tumors compared to tumors of a smaller size. These results support the validation of SNLB for tumors up to 50 mm.

[Sentinel lymph node-multicentric and multifocal tumors: a valid technique?]

Sentinel node biopsy without complementary axillary lymph node dissection was validated for T1-2 N0 unifocal breast cancer without previous treatment since several years. In the situation of multifocal multicentric breast tumors, this procedure was considered as a contraindication. The aim of this work was to analyse literature results to determine if sentinel lymph node biopsy can be considered as a valid option without complementary axillary lymph node dissection for negative sentinel lymph node.

[Relevance of the sentinel lymph node biopsy in breast multifocal and multicentric cancer]

OBJECTIVES

The sentinel lymph node biopsy is a gold standard in the management of breast cancer. Its role in multifocal or multicentric tumors is still evolving. The aim of this study is to assess the feasibility and pertinence of sentinel lymph node biopsy in multifocal and multicentric tumors based on a systematic review of literature.

METHODS

A systematic review was conducted searching in the following electronic databases PubMed using "sentinel lymph node biopsy", "breast cancer", "multifocal tumor", "multicentric tumor" and "multiple tumor" as keywords. We included original articles published between 2000 and 2014, both French and English, studying feasibility of sentinel lymph node biopsy in invasive breast cancer, multicentric and/or multifocal tumors. The first end point was success rate and false negative rate.

RESULTS

Twenty-six articles were included in this literature review, with 2212 cases (782 multifocal, 737 multicentric and 693 multiple tumors). Percentage of tumors whose stage was higher than stage T2 ranged from 0 to 86.3%. Success rate average was 83.1%. False negative average was 8.2%. False negative rate was less than 10% in 15 articles. Mean of sentinel lymph node biopsy was 2 (1-9). The average rate of sentinel lymph node positive was 50.6%. Axillary recurrence rate was 0.5%.

CONCLUSION

Despite the methodological biases of the studies included in this review of literature, the false negative rate of sentinel node biopsy in multifocal and multicentric breast cancers are less than 10% with a low rate of axillary recurrence. Despite the lack of randomized study, this procedure can be routinely performed in accordance with rigorous technical process.

A prospective validation study of sentinel lymph node biopsy in multicentric breast cancer: SMMaC trial

BACKGROUND

Multicentric breast cancer is often considered a contra-indication for sentinel lymph node (SLN) biopsy due to concerns with sensitivity and false negative rate. To assess SLN feasibility and accuracy in multicentric breast cancer, the multi-institutional SMMaC trial was conducted.

METHODS

In this study 30 patients with multicentric breast cancer and a clinically negative axilla were prospectively included. Periareolar injection of radioisotope and blue dye was administered. In all patients SLN biopsy was validated by back-up completion axillary lymph node dissection.

RESULTS

the SLN was successfully identified in 30 of 30 patients (identification rate 100%). The incidence of axillary metastases was 66.7% (20/30). The false negative rate was 0% (0/20) and the sensitivity was 100% (20/20). The negative predictive value was 100% (10/10).

CONCLUSION

SLN biopsy in multicentric breast cancer seems feasible and accurate and should therefore be considered in patients with multicentric breast cancer and clinically negative axilla.

Comparison of the sentinel node procedure between patients with multifocal and unifocal breast cancer in the EORTC 10981-22023 AMAROS Trial: identification rate and nodal outcome

INTRODUCTION

Multifocal breast cancer is associated with a higher risk of nodal involvement compared to unifocal breast cancer and the drainage pattern from multifocal localisations may be different. For this reason, the value of the sentinel node biopsy (SNB) procedure for this indication is debated. The aim of the current analysis was to evaluate the sentinel node identification rate and nodal involvement in patients with a multifocal tumour in the EORTC 10981-22023 AMAROS trial.

PATIENTS AND METHODS

From the first 4000 registered patients, 342 were identified with a multifocal tumour on histological examination and compared to a randomly selected control group of 684 patients with a unifocal tumour. The outcome of the SNB was assessed.

RESULTS

The sentinel node was identified in 96% of the patients with a multifocal tumour and in 98% of those with unifocal disease. In the multifocal group, 51% had a metastasis in the sentinel node compared to 28% in the unifocal group; and further nodal involvement after a positive sentinel node was found in 40% (38/95) and 39% (39/101) respectively.

CONCLUSION

In this prospective international multicentre study, the 96% detection rate indicates that the SNB procedure can be highly effective in patients with a multifocal tumour. Though the tumour-positive rate of the sentinel node was twice as high in the multifocal group compared to the unifocal group, further nodal involvement after a positive sentinel node was similar in both groups. This suggests that the SNB procedure is safe in patients with multifocal breast cancer.

Causes of false-negative sentinel node biopsy in patients with breast cancer

Background

Sentinel lymph node (SLN) biopsy has replaced axillary lymph node dissection as the routine staging procedure in clinically node-negative breast cancer. False-negative SLN biopsy results in misclassification and may cause undertreatment of the disease. The aim of this study was to investigate whether serial sectioning of SLNs reveals metastases more frequently in patients with false-negative SLNs than in patients with true-negative SLNs.

Methods

This was a case–control study. Tissue blocks from patients with false-negative SLNs, defined as tumour-positive lymph nodes excised at completion axillary dissection or a subsequent axillary tumour recurrence, were reassessed by serial sectioning and immunohistochemical staining. For each false-negative node, two true-negative SLN biopsies were analysed. Tumour and node characteristics in patients with false-negative SLNs were compared with those in patients with a positive SLN by univariable and multivariable regression analysis.

Results

Undiagnosed SLN metastases were discovered in nine (18 per cent) of 50 patients in the false-negative group and in 12 (11.2 per cent) of 107 patients in the true-negative group (P = 0.245). The metastases were represented by isolated tumour cells in 14 of these 21 patients. The risk of a false-negative SLN was higher in patients with hormone receptor-negative (odds ratio (OR) 2.50, 95 per cent confidence interval 1.17 to 5.33) or multifocal tumours (OR 3.39, 1.71 to 6.71), or if only one SLN was identified (OR 3.57, 1.98 to 6.45).

Conclusion

SLN serial sectioning contributes to a higher rate of detection of SLN metastasis. The rate of upstaging of the tumour is similar in false- and true-negative groups of patients.

The false-negative rate of sentinel node biopsy in patients with breast cancer: a meta-analysis

BACKGROUND

In sentinel node surgery for breast cancer, procedural accuracy is assessed by calculating the false-negative rate. It is important to measure this since there are potential adverse outcomes from missing node metastases. We performed a meta-analysis of published data to assess which method has achieved the lowest false-negative rate.

METHODS

We found 3,588 articles concerning sentinel nodes and breast cancer published from 1993 through mid-2011; 183 articles met our inclusion criteria. The studies described in these 183 articles included a total of 9,306 patients. We grouped the studies by injection material and injection location. The false-negative rates were analyzed according to these groupings and also by the year in which the articles were published.

RESULTS

There was significant variation related to injection material. The use of blue dye alone was associated with the highest false-negative rate. Inclusion of a radioactive tracer along with blue dye resulted in a significantly lower false-negative rate. Although there were variations in the false-negative rate according to injection location, none were significant.

CONCLUSIONS

The use of blue dye should be accompanied by a radioactive tracer to achieve a significantly lower false-negative rate. Location of injection did not have a significant impact on the false-negative rate. Given the limitations of acquiring appropriate data, the false-negative rate should not be used as a metric for training or quality control.

Accuracy of sentinel lymph node biopsy in large and multifocal/multicentric breast carcinoma--a systematic review

BACKGROUND

While sentinel lymph node biopsy (SLNB) is established in the management of small unifocal breast cancer its role in management of multifocal (MF), multicentric (MC) and larger tumors is still evolving.

METHODS

Medline was searched; studies meeting pre-determined criteria were included. Data were extracted and entered into evidence tables.

RESULTS

Twenty six studies met inclusion criteria and reported data on accuracy; no randomized trials were identified. For MF cancers (n = 314 cases), success rate for identification of an SLN was 86-94%, SLN positivity rate 42-59%, false negative rate (FNR) 0-33% and overall accuracy 78-100%. For MC (n = 294 cases): success rate 92-100%, SLN positivity rate 25-61%, FNR 4-8% and accuracy 96-100%. For 'multiple breast cancer' (studies combining MF/MC cases; n = 996 cases): success rate 92-100%, SLN positivity rate 12-63%, FNR 0-25%, and accuracy 82-100%. For larger tumors (n = 1912 cases): success rate 86-100%, SLN positivity rate 49-77%, FNR 3-18% and accuracy 85-98%. For MC/MF and larger cancers overall non-SLN positivity rates were up to 82%; axillary recurrence rates were low but seldom reported.

CONCLUSION

There are no randomized trials evaluating the safety of SLNB in MF/MC and larger breast cancers. Based on limited evidence, success rate and FNR appear to be similar to those for small unifocal cancers, however node positivity rates are higher and rates of non-SLN positivity are very high. Awareness of these issues is essential when recommending SLNB based axillary management for these higher-risk tumors.

False negative rate of sentinel lymph node biopsy in multicentric and multifocal breast cancers may be higher in cases with large additive tumor burden

We aimed to evaluate the feasibility of sentinel lymph node biopsy (SLNB) in multicentric/ multifocal breast cancer. In this prospective study, 23 women with multicentric/multifocal breast cancer underwent SLNB at our institution from April 2002 to February 2006. Presence of preoperative axillary metastases was confirmed by FNA. Patients underwent sub-areolar radiopharmaceutical injection +/- isosulfan blue to perform SLNB, then completion ALND. The false-negative (FN) rate of SLNB was determined based upon final pathology. Twenty women with multicentric and three with multifocal invasive carcinoma were enrolled. The SLN identification rate was 100%. The overall FN rate of SLNB was 15% (95% CI 0.0466, 0.4281). Both cases with FN SLNB had multicentric disease, pathologic stage III breast cancer and a larger tumor burden compared with the study population. SLNB using sub-areolar injection is feasible for patients with multicentric/multifocal breast cancer yet may be associated with a higher FN rate in patients with large additive tumor burden.

Sentinel node biopsy in breast cancer patients with large or multifocal tumors

BACKGROUND

The axillary recurrence (AR) rate after negative sentinel node biopsy (SNB) in patients with high risk of axillary metastases is largely unknown. The aim of this study was to analyze the risk factors for isolated AR after negative SNB with special interest in large or multifocal tumors.

METHODS

A prospective SNB registry was analyzed for 2,408 invasive breast cancer patients operated between 2001 and 2007. No axillary clearance was performed in 1,309 cases with a negative SNB, including 1,138 small unifocal tumors, 121 small multifocal tumors, 48 large unifocal tumors, and 2 large multifocal tumors.

RESULTS

Six (0.5%) isolated AR were observed during a median follow-up of 43 months. Four (0.4%) patients with small unifocal tumors and two (1.6%) with small multifocal tumors had isolated AR (p = 0.179). None of the patients with large unifocal or multifocal tumors had isolated AR. Instead of tumor size and multifocality, estrogen receptor negativity (p < 0.001), nuclear grade III (p < 0.001), Her-2 status (p = 0.002), no radiotherapy (p = 0.005), and mastectomy (p = 0.005) were found to be associated with AR.

CONCLUSIONS

A remarkable proportion of patients with large unifocal tumors and small multifocal tumors may avoid unnecessary AC due to tumor negative SNB, without an excessive risk of AR.

Increased lymph node positivity in multifocal and multicentric breast cancer

BACKGROUND

Multifocal and multicentric (MF/MC) breast cancers have been reported to be associated with increased lymph node metastases. The limited data on this issue prompted us to investigate the pathologic and clinical differences between unifocal and MF/MC breast cancer.

STUDY DESIGN

Between 1990 and 2002, 1,322 patients with operable invasive breast cancer underwent a definitive operation at our Breast Clinic. Patients with MF/MC breast cancer (n=147, 11%) were compared with patients with unifocal breast cancer (n=1,175; 89%) in terms of pathologic and clinical characteristics.

RESULTS

Patients with MF/MC were found to have a higher frequency of lymph node metastases when the largest diameter was used as a tumor size estimate for MF/MC cancer (unifocal T1 and T2, 35% and 49%, respectively, versus MF/MC T1 and T2, 48% and 67%, respectively; p=0.05 and p=0.003, respectively). When the combined diameter assessment was used, the frequency of lymph node positivity was similarly higher in MF/MC patients versus unifocal patients (unifocal T1 and T2, 35% and 49%, respectively, versus MF/MC T1 and T2, 49% and 61%, respectively; p=0.08 and p=0.046, respectively). At a median followup of 55 months (range 12 to 153 months), 5-year disease-free survival (DFS; unifocal, 88% versus MF/MC, 82%, p=0.14) and overall survival (OS) rates (unifocal, 92% versus MF/MC, 93%, p=0.43) did not show any significant difference between two groups.

CONCLUSIONS

Our data suggest that breast tumors with multiple foci have a different biology, with an increased metastatic potential to axillary lymph nodes, regardless of tumor size, that reflects an advanced stage. The clinical relevance of the currently used TNM classification system, which uses the diameter of the largest nodule, is supported by our findings.

Outcomes following sentinel lymph node biopsy for breast cancer

Evaluation of axillary lymph nodes for metastatic involvement is the most significant factor in gauging prognosis in breast cancer patients. Complete axillary dissection can be associated with significant morbidity. Therefore, sentinel node biopsy was developed to sample nodes and avoid dissection in patients without clinical evidence of nodal involvement. While most surgeons currently perform the procedure, the technique remains unstandardized. Sentinel node identification rates, false-negative rates and procedural complication rates are the main outcomes measured and can depend significantly on variations in technique. Future studies on sentinel lymph node biopsy will probably focus on clarifying accuracy of the procedure in different clinical settings, delineating standard technical practice guidelines and further achieving improved outcomes.

Sentinel node biopsy in patients with multiple breast cancer

BACKGROUND

Multicentric or multifocal breast cancer is considered a limitation for sentinel lymph node biopsy (SLNB). Studies showing that all quadrants of the breast drain via common afferent lymphatic channels indicate that multiple tumors do not affect lymphatic drainage. We therefore assessed the accuracy of SLNB in patients with multiple breast tumors.

METHODS

Of the 942 breast cancer patients who underwent SLNB using radioisotope at Asan Medical Center between January 2003 and December 2006, 803 had unifocal and 139 had multiple tumors. Axillary dissection after SLNB was performed on 884 patients, 757 with unifocal and 127 with multiple tumors. All patients underwent lymphatic scintigram for removal of sentinel lymph nodes (SLNs). The clinical characteristics and accuracy of SLNB was compared in patients with unifocal and multiple breast cancer.

RESULTS

In the multiple tumor group, 2.68 +/- 0.84 SLNs were identified in 136 of 139 patients (identification rate, 97.84%); 81.5% of SLNs were identified by scintigram. The incidence of axillary metastases was 29.50% (41/139). SLNB accuracy was 97.63% (124/127), with a false negative (FN) rate of 7.89% (3/38). In the unifocal group, 2.67 +/- 0.96 SLNs were identified in 787 of 803 patients (identification rate, 98.00%); 84.8% of SLNs were identified by scintigram. The incidence of axillary metastasis was 22.04% (177/803). SLNB accuracy was 98.02% (742/757), with a FN rate of 8.62% (15/174). The accuracy and FN rate of SLNB did not differ significantly between unifocal and multiple breast cancer.

CONCLUSION

The accuracy of SLNB in multiple breast cancer is comparable to its accuracy in unifocal cancer. These findings indicate that SLNB can be used an as alternative to complete axillary lymph node dissection in patients with multiple breast tumors.

Sentinel node biopsy for breast cancer larger than 3 cm in diameter

Background

Sentinel node biopsy (SNB) is a standard staging procedure in early breast cancer. Its suitability for larger tumours has been questioned. This study evaluated the reliability of SNB in women with invasive breast cancer larger than 3 cm in diameter who were clinically axillary node negative.

Methods

Some 109 women with a tumour larger than 3 cm on pathological analysis were identified from the Swedish prospective SNB database. They were included if a completion axillary clearance was planned, regardless of SNB results.

Results

The sentinel node detection rate was 103 (94·5 per cent) of 109. The overall false-negative rate was eight (13 per cent) of 64. Although a preoperative diagnosis of multifocal tumour was an exclusion criterion, 16 such cases were revealed on postoperative pathological examination. The false-negative rate in this subgroup was higher than that in women with a unifocal tumour (four (31 per cent) of 13 versus four (8 per cent) of 51; P = 0·012). No other significant predictors of a false-negative sentinel node biopsy were identified.

Conclusion

SNB is feasible in patients with unifocal breast tumours larger than 3 cm. When large tumour size coincides with multifocality, however, the false-negative rate seems to be increased and a completion axillary clearance should be considered even if the SNB is negative.

Sentinel lymph node biopsy in multiple breast cancer using subareolar injection of the tracer

We performed subdermal injection of (99m)Tc-labelled albumin combined with subareolar (SA) injection of blue dye to axillary lymphatic mapping and sentinel lymph node biopsy (SLNB) in patients with multifocal and multicentric breast cancer to evaluate the feasibility and accuracy of this technique. A retrospective analysis of our experience on 235 SLNB showed that 30(12.7%) had multiple cancer (MC) on final pathologic examination and was considered in relation to the aim of the study. Mean age was 57.19 years (range 24-90). Mean number of SLNs identified was 1.93 (range 1-5). Mean number of axillary LNs examined was 18.10 (range 12-27). Overall successful identification was 100% with a false negative (FN) rate of 6.25%. Overall accuracy of lymphatic mapping and sensitivity was 96.6% and 93.7%, respectively. SLNB using the SA injection technique may be an alternative to complete axillary dissection in patients with multiple breast cancers and a clinically negative axilla.

Positive and negative aspects of sentinel lymph node biopsy in breast cancer

The sentinel lymph node (SLN) is the first lymph node to receive lymphatic drainage from a tumor. SLN biopsy has become a mainstay of breast cancer management and is used when the axilla is clinically clear of disease. Staging of the axilla in breast cancer is used to predict prognosis and in planning adjuvant treatment. SLN biopsy is not used where there has been previous axillary or breast radiotherapy or surgery, locally advanced or inflammatory disease and stage IV disease. Controversies remain in several specific clinical situations, including management of the axilla following detection of a positive SLN. There are no sufficiently robust predictive tumor features to prevent completion axillary dissection in these cases. However, there is evidence that immediate axillary surgery for operable, clinically node-negative breast cancer provides no survival benefit and may be unnecessary for many women. SLN biopsy may have a role after neoadjuvant chemotherapy, sparing some women from axillary node dissection. Further work is required to ascertain SLN biopsy sensitivity prior to its routine use in the clinic for multicentric and multifocal disease.

Sentinel lymph node biopsy as the new standard of care in the surgical treatment for breast cancer

During the recent years, based on the results of validation studies, the sentinel lymph node biopsy has replaced routine axillary dissection as the new standard of care in early breast cancer. The technique represents a minimally invasive, highly accurate method for axillary staging, which could spare approximately 65-70% of patients unnecessary axillary dissection and its related morbidity. Several technical and clinical controversies have been raised during the development of this new technique; the authors review the most important issues, some questions have already been answered and others are still under debate. As far as the technical aspects are concerned, mapping techniques, appropriate surgical training, options for pathological examination of sentinel lymph nodes and the issue of nonaxillary sentinel lymph nodes are discussed. An update on clinical controversies demonstrates that factors such as large tumor size, palpable axillary nodes, multifocality and multicentricity, previous breast and axillary surgery, and pregnancy are no longer regarded as absolute contraindications for sentinel lymph node biopsy. Feasibility, accuracy and timing of sentinel lymph node biopsy in patients undergoing neoadjuvant chemotherapy remain unsolved issues, as well as the indication of the technique for some subgroups of in situ lesions. Finally, one of the most attractive open forums for debate will be discussed: whether or not completion of axillary dissection in the case of positive SLN is always required.

Impact of Patient- and Disease-Specific Factors on SLNB in Breast Cancer Patients. Are Current Guidelines Justified?

BACKGROUND

The evidence on which to base guidelines for sentinel lymph node biopsy (SLNB) in breast cancer is still limited. In order to facilitate the further implementation of renewed guidelines, we evaluated patient- and disease-specific factors for their impact on the results of SLNB.

MATERIALS AND METHODS

Prospective data acquisition from patients undergoing surgery for primary invasive breast cancer was performed. All patients underwent SLNB using the radiocolloid or the combined technique. The association of patient- and disease-specific factors to detection rate and false-negative rate was calculated using univariate and multivariate analyses (P < 0.05 considered as significant). Calculation of the false-negative rate was based on patients who underwent a backup axillary dissection.

RESULTS

Among 455 consecutively enrolled patients, a significant inverse association to the detection rate was found for extracapsular extension of non-SLN metastases, body mass index (BMI), number of involved lymph nodes, pT category, tumor size, and age. A significant association to the false-negative rate to identify macrometastases was found for pT category, tumor size, and grading. Other factors, such as prior surgery, multicentric tumor growth, or vascular invasion, showed no influence. A cut-point analysis revealed that a tumor size of 2 cm separated the collective of patients with the highest significance in regard to the false-negative rate (9% vs. 25%).

CONCLUSION

Our results indicate that SLNB can be safely used in elderly and obese patients with multicentric tumors and those having undergone prior surgery for benign breast disease. However, the method should be applied with caution in patients with tumors larger than 2 cm.

Multifocality and multicentricity are not contraindications for sentinel lymph node biopsy in breast cancer surgery

BACKGROUND

After the availability of the results of validation studies, the sentinel lymph node biopsy (SLNB) has replaced routine axillary dissection (AD) as the new standard of care in early unifocal breast cancers. Multifocal (MF) and multicentric (MC) tumors have been considered a contraindication for this technique due to the possible incidence of a higher false-negative rate. This prospective study evaluates the lymphatic drainage from different tumoral foci of the breast and assesses the accuracy of SLNB in MF-MC breast cancer.

PATIENTS AND METHODS

Patients with preoperative diagnosis of MF or MC infiltrating and clinically node-negative (cN0) breast carcinoma were enrolled in this study. Two consecutive groups of patients underwent SLN mapping using a different site of injection of the radioisotope tracer: a) "2ID" Group received two intradermal (i.d.) injections over the site of the two dominant neoplastic nodules. A lymphoscintigraphic study was performed after each injection to evaluate the route of lymphatic spreading from different sites of the breast. b) "A" Group had periareolar (A) injection followed by a conventional lymphoscintigraphy. At surgery, both radioguided SLNB (with frozen section exam) and subsequent AD were planned, regardless the SLN status.

RESULTS

A total 31 patients with MF (n = 12) or MC (n = 19) invasive, cN0 cancer of the breast fulfil the selection criteria. In 2 i.d. Group (n = 15) the lymphoscintigraphic study showed the lymphatic pathways from two different sites of the breast which converged into one major lymphatic trunk affering to the same SLN(s) in 14 (93.3%) cases. In one (6.7%) MC cancer two different pathways were found, each of them affering to a different SLN. In A Group (n = 16) lymphoscintigraphy showed one (93.7%) or two (6.3%) lymphatic channels, each connecting areola with one or more SLN(s). Identification rate of SLN was 100% in both Groups. Accuracy of frozen section exam on SLN was 96.8% (1 case of micrometastasis was missed). SLN was positive in 13 (41.9%) of 31 patients, including 4 cases (30.7%) of micrometastasis. In 7 of 13 (53.8%) patients the SLN was the only site of axillary metastasis. SLNB accuracy was 96.8% (30 of 31), sensitivity 92.8 (13 of 14), and false-negative rate 7.1% (1 of 14). Since the case of skip metastasis was identified by the surgeon intraoperatively, it would have been no impact in the clinical practice.

CONCLUSION

Our lymphoscintigraphic study shows that axillary SLN represents the whole breast regardless of tumor location within the parenchyma. The high accuracy of SLNB in MF and MC breast cancer demonstrates, according with the results of other series published in the literature, that both MF and MC tumors do not represent a contraindication for SLNB anymore.

Sentinel Lymph Node Biopsy for Breast Cancer: Current Controversies

Sentinel lymph node biopsy (SLNB) has replaced the routine level I and II axillary lymph node dissection (ALND) for women with clinically node-negative T1 and T2 breast cancer. Studies have shown that SLNB is highly predictive of axillary nodal status with a false-negative of rate less than 10%. Our purpose was to address some of the ongoing controversies about this procedure, including technical issues, use of preoperative lymphoscintigraphy, internal mammary lymph node biopsy, criteria for patient selection (in intraductal carcinoma?), its staging accuracy, and the clinical approach when a SLNB was found to be negative or positive on pathologic examination. After the revision of the American Joint Committee on Cancer (AJCC) staging system for breast cancer in 2002, the evaluation of internal mammary lymph nodes and determination of micrometastases by hematoxylin-eosin or by immunohistochemistry have become increasingly important in staging of patients. Recent guideline recommendations developed by the American Society of Clinical Oncology (ASCO) Expert Panel in 2005 are also discussed. Long-term follow-up results of ongoing studies will provide more accurate assessment of the prognostic significance of SLNB and its value in the prevention of breast cancer-related morbidity in axillary staging compared to ALND.

Mammographic detection and staging of invasive lobular carcinoma

The aim of the study was to evaluate mammography in detecting and staging of invasive lobular carcinoma (ILC) in order to assess the performance and impact of observer variability. Forty-two cases of ILC were retrospectively evaluated twice by two breast radiologists. Mammographic performance as well as intra- and interobserver variations was evaluated. Thirty-five percent to 37% of the cases were understaged. The largest differences between radiologists were found in the breast imaging reporting and data system (BIRADS) classification and staging performance. These results can have serious influence on patient management.

Multicentric Breast Cancer: A New Indication for Sentinel Node Biopsy—A Multi-Institutional Validation Study

Purpose

Multicentric breast cancer has been considered to be a contraindication for sentinel node (SN) biopsy (SNB). In this prospective multi-institutional trial, SNB-feasibility and accuracy was evaluated in 142 patients with multicentric cancer from the Austrian Sentinel Node Study Group (ASNSG) and compared with data from 3,216 patients with unicentric cancer.

Patients and Methods

Between 1996 and 2004, 3,730 patients underwent SNB at 15 ASNSG-affiliated hospitals. Patient data were entered in a multicenter database. One hundred forty-two patients presented with multicentric invasive breast cancer and underwent SNB.

Results

Intraoperatively, a mean number of 1.67 SNs were excised (identification-rate, 91.5%). The incidence of SN metastases was 60.8% (79 of 130). This was confirmed by axillary lymph node dissection (ALND) in 125 patients. Of patients with positive SNs, 60.8% (48 of 79) showed involvement of nonsentinel nodes (NSNs), as did three patients with negative SNs (false-negative rate, 4.0). Sensitivity, negative predictive value, and overall accuracy were 96.0%, 93.3%, and 97.3%, respectively. Ninety-one percent of the patients underwent mastectomy, and 9% were treated with breast conserving surgery. None of the patients have shown axillary recurrence so far (mean follow-up, 28.8 months). Compared with 3,216 patients with unicentric cancer, there was a significantly higher rate of SN metastases as well as in NSNs, whereas there was no difference in detection and false-negative rates.

Conclusion

Multicentric breast cancer is a new indication for SNB without routine ALND in controlled trials. Given adequate quality control and an interdisciplinary teamwork of surgical, nuclear medicine, and pathology units, SNB is both feasible and accurate in this disease entity.

Sentinel lymph node biopsy in multicentric breast cancer. The experience of the European Institute of Oncology

AIM

To present our experience with sentinel lymph node biopsy (SLNB) performed in patients with multicentric breast cancer.

METHODS

Between May 2001 and May 2004, 42 patients with multicentric breast cancer and a clinically negative axilla underwent lymphatic mapping either by a single subareolar (n = 25) or a double peritumoral/subdermal injection (n = 17) of 99Tc-HSA nanocolloids. The sentinel lymph node (SLN) was evaluated by intraoperative frozen section and axillary dissection was performed only in case of positive SLN.

RESULTS

Mean age was 49 years (range 25-78). Mean number of SLNs identified by lymphoscintigraphy was 1.36 (range 1-5) and mean number of SLNs removed at surgery was 1.55 (range 1-5), with an identification rate of 100%. The mean number of hot spots identified by lymphoscintigraphy was similar in patients who underwent single or double injections (1.36 and 1.35, respectively). In 21 of 42 patients the SLN was positive, and in seven of these 21 patients the SLN was the only positive node. After a median follow-up of 24 months no overt axillary metastases occurred in patients with negative SLN.

CONCLUSIONS

The number of SLNs is not dependent on the number and site of injections. SLNB is our standard procedure for nodal staging in patients with multicentric breast cancer and a clinically negative axilla.

A further validation of subareolar injection technique for breast sentinel lymph node biopsy

BACKGROUND

In this study we performed subdermal injection of (99m)Tc-labeled albumin combined with subareolar (SA) injection of blue dye, and we compared this technique with two techniques previously used in terms of the success of sentinel lymph node (SLN) identification, false-negative (FN) rate, and the overall accuracy and sensitivity of the three procedures. In all patients we performed a complete axillary lymph node dissection.

METHODS

From January 1999 to September 2004, a total of 195 patients with localized breast cancer were treated. Patients were subdivided into three groups. In patients in group 1 (n = 115; January 1999 to December 2001), lymphoscintigraphy together with injection of vital dye was performed; in group 2 (n = 40; January to October 2002), SA injection of blue dye alone was performed; and in group 3 (n = 40; November 2002 to September 2004), SA injection of blue dye and subdermal injection of radioisotope was performed.

RESULTS

The success rate of identifying an SLN by a combination of the two techniques was 95% in group 1 and 100% in group 3. The FN rate was 9% in group 1 and 0% in groups 2 and 3. The overall accuracy of lymphatic mapping was 97% in group 1 and 100% in groups 2 and 3. Sensitivity was 91% in group 1 and 100% in groups 2 and 3.

CONCLUSIONS

This study of SA injection for SLN biopsy using dual tracers demonstrates a high SLN identification rate and an absent FN rate. We propose that injection into the SA plexus is the optimal way to perform lymphatic mapping of the breast. This technique seems to be feasible even in patients with multicentric cancers.

Sentinel Node Biopsy Before Neoadjuvant Chemotherapy Spares Breast Cancer Patients Axillary Lymph Node Dissection

BACKGROUND

Neoadjuvant chemotherapy in breast cancer patients is a valuable method to determine the efficacy of chemotherapy and potentially downsize the primary tumor, which facilitates breast-conserving therapy. In 18 studies published about sentinel node biopsy after neoadjuvant chemotherapy, the sentinel node was identified in on average 89%, and the false-negative rate was on average 10%. Because of these mediocre results, no author dares to omit axillary clearance just yet. In our institute, sentinel lymph node biopsy is performed before neoadjuvant chemotherapy. The aim of this study was to evaluate our experience with this approach.

METHODS

Sentinel node biopsy was performed before neoadjuvant chemotherapy in 25 T2N0 patients by using lymphoscintigraphy, a gamma ray detection probe, and patent blue dye. Axillary lymph node dissection was performed after chemotherapy if the sentinel node contained metastases.

RESULTS

Ten patients had a tumor-positive axillary sentinel node, and one patient had an involved lateral intramammary node. Four patients had additional involved nodes in the completion lymph node dissection specimen. The other 14 patients (56%) had a tumor-negative sentinel node and did not undergo axillary lymph node dissection. No recurrences have been observed after a median follow-up of 18 months.

CONCLUSIONS

Fourteen (56%) of the 25 patients were spared axillary lymph node dissection when the sentinel node was found to be disease free. Performing sentinel node biopsy before neoadjuvant chemotherapy seems successful and reliable in patients with T2N0 breast cancer.

Factors predicting the sentinel and non-sentinel lymph node metastases in breast cancer

The sentinel lymph node (SLN) is the only focus of axillary metastasis in a significant proportion of patients. In this single institutional study, clinicopathologic characteristics were investigated to determine the factors predicting the status of a SLN biopsy and the metastatic involvement of non-SLNs. Data were retrospectively reveiwed for 400 consecutive patients with clinical T1/T2 N0 breast cancer who underwent a SLN biopsy including axillary and/or internal mammary lymph nodes. The SLNs were evaluated by using the new AJCC staging criteria following multiple sectioning and immunohistochemical (IHC) analyses of nodes. The SLN contained metastases in 148 patients (38.5%) including 18 patients (12.2%) with micrometastases (<or=0.2 mm) and 130 patients (87.8%) with macrometastases (>0.2 cm). Five patients had isolated tumor cells detected by IHC (<or=0.2 mm, N(0i)). Patients with tumor size more than 2 cm (T1, 29.8% versus T2, 51.6%; OR=2.31, 95% CI, 1.50-3.56) and lymphovascular invasion (LVI-, 30.3% versus LVI+, 51.3%; OR=2.07, 95% CI, 1.34-3.19) were more likely to have positive SLNs in both univariate and multivariate analyses. Among patients with a positive SLN biopsy, those with T2 tumors (versus T1; 63.1% versus 36.9; OR=2.93, 95% CI, 1.43-6.04), macrometastases in SLNs (versus micrometastases; 88.9% versus 11.1%; OR=8.83; 95% CI, 1.82-42.87) and extracapsular node extension (versus without extracapsular node extension; 65.4% versus 34.6%; OR, 2.23; 95% CI, 1.05-4.72) were more likely to have non-SLN metastases in both univariate and multivarite analyses. These results indicate that clinicopathologic factors might be helpful to select patients who were less likely to have negative SLN or non-SLNs. However, additional factors are still needed to be identified to omit surgical axillary staging.

Multicentre validation study of sentinel node biopsy for staging in breast cancer

BACKGROUND

The aim of this study was to validate sentinel node biopsy for axillary staging after the initial learning phase, and to analyse factors associated with false-negative biopsies.

METHODS

Some 675 patients, who had standard sentinel node biopsy followed by level I and II axillary clearance in one of 20 hospitals in Sweden and were operated on by 36 different surgeons, were recruited prospectively.

RESULTS

The overall detection rate was 94.5 per cent. It varied between surgeons but was not influenced by the number of operations per surgeon. Moreover, it was lower among older patients. The overall false-negative rate was 7.7 per cent. This rate was not affected by patient age, tumour histological type or Elston grade, but was increased in patients with multifocal tumours. Some 21 per cent of patients with a multifocal tumour diagnosed on postoperative histopathological analysis had a false-negative biopsy compared with 5.6 per cent of those with unifocal tumours (P = 0.004).

CONCLUSION

Sentinel node biopsy was shown to be a reliable method for axillary staging of unifocal breast tumours.

Sentinel lymph nodes and breast carcinoma: analysis of 70 cases by frozen section

BACKGROUND

The sentinal node biopsy (SNB) is a reliable method for determining the status of the regional lymph nodes in patients with breast cancer. SNB technology is evolving rapidly, but no standardization has yet been accomplished. The aim of this study is to discuss the accuracy of this procedure and the optimal method for identifying micrometastases.

METHODS

We collected data from 70 women with primary invasive breast carcinoma who underwent SNB for breast cancer. We examined two frozen sections levels from each half of each lymph node, as well as a cytology imprint before arriving at the frozen section diagnosis. Immunohistochemistry with pancytokeratin (AE1/AE3) was done on the paraffin sections. For the association between the lymph node size and the possibility of metastases, Student's t test was used and a P value of less than 0.05 was regarded as significant.

RESULTS

The number of patients with metastases in SNB was 19, from which 15 cases were correctly diagnosed in frozen sections/imprints and four cases were false negative. The axillary toilet from all cases with SNB metastases smaller than 2 mm showed no additional positive nodes. Lymph node diameter showed a significant association with sentinel node status (P<0.0001).

CONCLUSION

Frozen section examination of SNB from patients with breast carcinoma is both specific (100%) and sensitive (79%). Diagnosis of lobular carcinoma can be difficult, and may require immunohistochemistry with cytokeratin for diagnosis. Small metastases in a non-optimal frozen section may be difficult to discern. Cytology imprints add nothing to the diagnosis.

Non-axillary breast cancer recurrences after sentinel node biopsy

BACKGROUND AND OBJECTIVES

The primary lymphatic pathway of patients with breast cancer is toward the axilla, but lymph drainage is also possible towards the internal mammary chain and the supraclavicular fossa. In the current article, the development of breast cancer recurrences at these two sites after sentinel lymph node biopsy is reviewed.

METHODS

Since 1997, 803 patients underwent sentinel lymph node biopsy with intratumoral injection of 99mTc-nanocolloid and patent blue dye in The Netherlands Cancer Institute. All sentinel nodes as visualized on the lymphoscintigraphy images were pursued. The patients were followed prospectively for a median period of 34 months. Patients with a lymph node recurrence outside the axilla were identified and their lymphatic mapping procedures were reviewed.

RESULTS

Four of the 803 patients (0.5%) developed regional lymph node recurrences outside the axilla. One recurrence was located in the internal mammary chain, the other three in the supraclavicular bed. One or two of these patients also had an axillary recurrence. The sentinel node procedure had failed in two of the four patients.

CONCLUSION

The incidence of nodal recurrences outside the axilla is low. Although all extra-axillary sentinel nodes were pursued, some of these recurrences concern missed sentinel nodes that harbor metastasis. Identification of all sentinel nodes and subsequent treatment of the involved basins may reduce the risk of breast cancer recurrences in these unusual locations.

Evidence-Based Medicine Applied to Sentinel Lymph Node Biopsy in Patients with Breast Cancer

Sentinel lymph node biopsy (SLNB) has not been examined using the principles of evidence-based medicine (EBM). Specifically, likelihood ratios have not been used to assess the validity of SLNB. The Surveillance, Epidemiology, and End Results (SEER) public database of the National Cancer Institute was used to establish the baseline or pretest probability of finding a positive lymph axillary node for each stage of breast cancer. Rates of false negative results of SLNB for all breast cancer stages were determined from the surgical literature. Positive and negative likelihood ratios (LR) were calculated. For each stage of breast cancer, the Bayesian nomogram was used to find the post-test probability of missing a metastatic axillary node when the SLN was negative. The SEER database of 213,292 female patients with breast cancer yielded the following rates of positivity of axillary lymph nodes for each breast tumor size: T1a, 7.8 per cent; T1b, 13.3 per cent; T1c, 28.5 per cent; T2, 50.2 per cent; T3, 70.1 per cent. The combined data from 13 published studies of SLNB (6444 successful SLNBs) demonstrated a false negative rate of 8.5 per cent. The LR of a negative test is 0.086. According to the nomogram, the chances of missing a positive node for stage of cancer are as follows: T1a, 0.7 per cent; T1b, 1.5 per cent; T1c, 3.0 per cent; T2, 7 per cent; T3, 18 per cent. The risk of missing a positive axillary node can accurately be estimated for each stage of breast cancer using the LR, which is much more useful than the simple false negative rate. Surgeons should use this information when deciding whether to perform SLNB and in their informed consent discussions.

Sentinel node biopsy is not sensible in breast cancer patients with large primary tumours

AIMS

We aimed to evaluate the outcome of sentinel node biopsy (SNB) in breast cancer patients with large primary tumours.

METHODS

Nine hundred and eighty-four patients with invasive breast cancer and SNB were studied. The histological tumour size was larger than 3 cm in 70 patients. The advantages of SNB like avoiding axillary clearance (AC) or more accurate staging by detecting micrometastases or parasternal sentinel node metastases were evaluated in relation to the tumour size.

RESULTS

Axillary metastases were detected in 351/914 patients with a tumour size of 3 cm or smaller and in 50/70 patients with larger tumours (p<<0.0001). Micrometastases or isolated tumour cells only, were observed in 134/351 node positive patients with tumours not larger than 3 cm and in 10/50 cases with larger tumours (p=0.022). Parasternal sentinel node metastases were detected in 17/914 patients with a tumour size of 3 cm or smaller and 2/70 patients with larger tumours (p=ns). AC was omitted because of tumour negative sentinel node findings 168 of the 232 patients with stage T1 a-b tumours and 281 of those 489 with T1c tumours. Twenty of the 70 patients with tumours larger than 3 cm avoided AC.

CONCLUSIONS

SNB is not sensible in breast cancer patients with tumours larger than 3 cm, because of the small proportion avoiding AC after SNB.

Clinical considerations in breast cancer sentinel lymph node mapping: A moffitt review

Lymphatic mapping redefined the clinical significance of axillary lymph nodes in the treatment of breast cancer. Current literature supports the concept that any patient diagnosed with invasive breast cancer should in fact have their sentinel lymph nodes evaluated. However, there are many cases of " special situations in lymphatic mapping " . These special situations mark an important point that should be considered: When and who should undergo lymphatic mapping? A summary of these considerations/cases will be the focus of this report.

Subareolar sentinel node biopsy for multiple breast cancers

BACKGROUND

Sentinel lymph node biopsy (SLNB) is deemed suitable only for unifocal breast cancers since multiple foci of cancers may drain to different nodes. We hypothesized that subareolar injection (SI) could identify the sentinel lymph nodes (SLN) accurately in patients with multiple cancers (MC) in the breast.

METHODS

We prospectively employed SI of lymphazurin or technetium sulfur colloid, or both, for the identification of SLN in patients with MC in the breast. All patients underwent axillary dissection to compute the accuracy of SLNB.

RESULTS

Forty patients presented with MC in the same breast between January 1996 and July 2002. Fifty-two percent (21 of 40) of patients had involvement of more than 1 quadrant; 18% (7 of 40) had more than 1 histologic type of cancers. SLNs were successfully identified in 100% of patients. Axillary disease was present in 63% (25 of 40) of patients. Sensitivity of SLNB was 100% and false negative rate was 0%. The SLN was the only node involved in 45% (18 of 40) of patients.

CONCLUSIONS

SLNB using the SI technique may be an alternative to complete axillary dissection in patients with multiple breast cancers.