The clinical significance of sentinel lymph node micrometastasis in breast cancer

Prospects of perfusion contrast-enhanced ultrasound (CE-US) in diagnosing axillary lymph node metastases in breast cancer: a comparison with lymphatic CE-US

Accurate diagnosis of lymph node (LN) metastasis is vital for prognosis and treatment in patients with breast cancer. Imaging 1modalities such as ultrasound (US), MRI, CT, and 18F-FDG PET/CT are used for preoperative assessment. While conventional US is commonly recommended due to its resolution and sensitivity, it has limitations such as operator subjectivity and difficulty detecting small metastases. This review shows the microanatomy of axillary LNs to enhance accurate diagnosis and the characteristics of contrast-enhanced US (CE-US), which utilizes intravascular microbubble contrast agents, making it ideal for vascular imaging. A significant focus of this review is on distinguishing between two types of CE-US techniques for axillary LN evaluation: perfusion CE-US and lymphatic CE-US. Perfusion CE-US is used to assess LN metastasis via transvenous contrast agent administration, while lymphatic CE-US is used to identify sentinel LNs and diagnose LN metastasis through percutaneous contrast agent administration. This review also highlights the need for future research to clarify the distinction between studies involving "apparently enlarged LNs" and "clinical node-negative" cases in perfusion CE-US research. Such research standardization is essential to ensure accurate diagnostic performance in various clinical studies. Future studies should aim to standardize CE-US methods for improved LN metastasis diagnosis, not only in breast cancer but also across various malignancies.

Reevaluating Axillary Lymph Node Dissection in Total Mastectomy for Low Axillary Burden Breast Cancer: Insights from a Meta-Analysis including the SINODAR-ONE Trial

Complete axillary lymph node dissection (cALND) was previously the standard of care for breast cancer (BC) patients with axillary node disease or macro-metastases found via sentinel lymph node biopsy (SLNB). However, due to significant morbidity, contemporary management now considers a more selective approach, influenced by studies like ACOSOG Z0011. This trial showed that cALND could be omitted without compromising local control or survival in patients with low axillary nodal disease burden undergoing breast-conserving therapy, radiotherapy, and systemic therapy. The relevance of this approach for women with low axillary nodal burden undergoing total mastectomy (TM) remained unclear. A PubMed search up to September 2023 identified 147 relevant studies, with 6 meeting the inclusion criteria, involving 4184 patients with BC and low-volume axillary disease (1-3 positive lymph nodes) undergoing TM. Postmastectomy radiotherapy receipt was similar in both groups. After a mean 7.2-year follow-up, both the pooled results and the meta-analysis revealed no significant differences in overall survival. The combined analysis of the published studies, including the subgroup analysis of the SINODAR-One trial, indicates no survival advantage for cALND over SLNB in T1-T2 breast cancer patients with 1-3 positive sentinel lymph nodes (pN1) undergoing mastectomy. This suggests that, following a multidisciplinary evaluation, cALND can be safely omitted. However, the impact of other patient, tumor, and treatment factors on survival requires consideration and therefore further prospective trials are needed for conclusive validation.

Prognosis and local treatment strategies of breast cancer patients with different numbers of micrometastatic lymph nodes

BACKGROUND

Lymph node micrometastasis is an important prognostic factor in breast cancer, but patients with different numbers of involved lymph nodes are all divided into the same N1mi stage without distinction. We designed this study to compare the prognosis and local treatment recommendations of N1mi breast cancer patients with different numbers of micrometastatic lymph nodes.

PATIENTS AND METHODS

A total of 27,032 breast cancer patients with T1-2N1miM0 stage from the Surveillance, Epidemiology, and End Results (SEER) database (2004-2019) who underwent breast surgery were included in this retrospective study. Patients were divided into three groups for prognosis comparison according to the number of micrometastatic lymph nodes: N1mi with 1 (Nmi = 1), 2 (Nmi = 2), or more (Nmi ≥ 3) involved lymph nodes. We explored the characteristics and survival outcomes of the population receiving different local treatments, including different axillary surgery types and whether receiving radiotherapy or not. Univariate and multivariate Cox proportional hazards regression analysis were used to compare the overall survival (OS) and breast cancer-specific survival (BCSS) in different groups. Stratified analyses and interaction analyses were also applied to explore the predictive significance of different involved lymph nodes numbers. Propensity score matching (PSM) method was utilized to balance the differences between groups.

RESULTS

Univariate and multivariate Cox regression analysis indicated that nodal status was an independent prognostic factor. After adjustment for other prognostic factors, there was a significant difference in prognosis between Nmi = 1 group and Nmi = 2 group [adjusted hazard ratio (HR) 1.145, 95% confidence interval (CI): 1.047-1.251, P = 0.003], and patients with Nmi ≥ 3 group had a significantly poorer prognosis (adjusted HR 1.679, 95% CI 1.589-2.407; P < 0.001). The proportion of N1mi patients only underwent sentinel lymph nodes biopsy (SLNB) gradually increased from 2010 (P_trend < 0.001). After adjusting for other factors, N1mi patients who underwent axillary lymph nodes dissection (ALND) was associated with significant survival benefit than SLNB (adjusted HR 0.932, 95%CI 0.874-0.994; P = 0.033), the same goes for receiving radiotherapy (adjusted HR 1.107, 95%CI 1.030-1.190; P = 0.006). Further stratified analysis showed that in the SLNB subgroup, radiotherapy was associated with a significant survival benefit (HR 1.695, 95%CI 1.534-1.874; P < 0.001), whereas in the ALND subgroup, there was no significant prognostic difference with or without radiotherapy (HR 1.029, 95%CI 0.933-1.136; P = 0.564).

CONCLUSION

Our study indicates that the increasing number of lymph node micrometastases was associated a worse prognosis of N1mi breast cancer patients. In addition, ALND does provide a significant survival benefit for these patients, while the benefit from local radiotherapy may be of even greater importance.

The prognostic significance of further axillary dissection for sentinel lymph node micrometastases in female breast cancer: A competing risk analysis using the SEER database

BACKGROUND

Sentinel lymph node (SLN) biopsy has been widely recognized as an excellent surgical and staging procedure for early-stage breast cancer, and its development has greatly improved the detection of micrometastases. However, the axillary treatment of micrometastasis has been the subject of much debate.

METHODS

We identified 427,131 women diagnosed with breast cancer from 2010 to 2018 in the Surveillance, Epidemiology, and End Results (SEER) database. Patients whose nodal status was micrometastases (pTxN1miM0) were classified into two groups: the SLNB only group and SLNB with complete ALND group, and we used these classifications to carry out propensity-score matching (PSM) analysis. The primary and secondary endpoints were OS and BCSS, respectively. We then implemented the Kaplan-Meier method and Cox proportional hazard model and used Fine and Gray competitive risk regression to identify factors associated with the risk of all-cause mortality.

RESULTS

After the PSM, 1,833 pairs were included in total. The SLNB with complete ALND showed no significant difference in OS (HR=1.04, 95% CI: 0.84-1.28, P=0.73) or BCSS (HR= 1.03, 95% CI: 0.79-1.35, P=0.82) compared to the SLNB only group, and axillary treatment was not associated with breast cancer-specific death (BCSD) (HR=1.13, 95% CI: 0.86-1.48, P=0.400) or other cause-specific death (OCSD) (HR=0.98, 95% CI:0.70-1.38, P=0.920). There was no statistically significant difference in the cumulative incidence of BCSD (Grey's test, P=0.819) or OCSD (Grey's test, P=0.788) for between the two groups either. For different molecular subtypes, patients in the SLNB only group showed no statistically significant differences from those in the SLNB with complete ALND group with Luminal A (HR=1.00, 95% CI:0.76-1.32, P=0.98) or Luminal B (HR=0.82, 95% CI:0.42-1.62, P=0.55) but similar OS to HER2-enriched (HR=1.58, 95% CI:0.81-3.07, P=0.19) or triple negative breast cancers (HR=1.18, 95% CI:0.76-1.81, P=0.46).

CONCLUSIONS

Our results suggest that in early breast cancer patients with micrometastasis, complete ALND does not seem to be required and that SLNB suffices to control locoregional and distant disease, with no significant adverse effects on survival compared to complete ALND.

Adjuvant chemotherapy for breast cancer patients with axillary lymph node micrometastases

BACKGROUND

The axillary lymph node status is one of the most important prognostic factors in patients with early breast cancer. However, the impact of axillary lymph node micrometastases on survival remains unclear. There are no consistent recommendations for adjuvant chemotherapy (CHT). In this context, we aimed to investigate the impact of micrometastases on the clinical outcome of breast cancer patients according to the adjuvant CHT performed.

PATIENTS AND METHODS

We conducted a retrospective population-based registry study of 26,465 patients aged between 24 and 97 years with primary breast cancer diagnosed between 2003 and 2017. Of these patients, 8856 with early breast cancer were eligible for analysis: 8316 (93.9%) were node negative and 540 (6.1%) had lymph node micrometastases.

RESULTS

The median follow-up was 7.2 years, with a confidence interval (CI) of 7.1-7.3 years. Patients with lymph node micrometastases (pN1mi) without adjuvant CHT have reduced 10-year overall survival (OS) and recurrence-free survival (RFS) compared to patients who had axillary lymph node micrometastases and received an adjuvant CHT. However, this effect disappeared after adjustment for age, tumor size and tumor grading. Furthermore, in the group of patients with lymph node micrometastases, the administration of adjuvant CHT did not improve OS or RFS, compared to patients with lymph node micrometastases without adjuvant CHT: hazard ratio for treated patients was 1.51 (95% CI 0.80-2.85, p = 0.208) for OS and 1.12 (95% CI 0.63-1.97, p = 0.705) for RFS.

CONCLUSION

Patients with axillary lymph node micrometastases showed a comparable outcome to node negative patients and their outcome was not significantly improved with CHT. Thus, axillary lymph node micrometastases should not be considered in the treatment decision.

Molecular analysis of sentinel lymph nodes in patients with breast cancer using one-step nucleic acid amplification (OSNA): Does not lead to overtreatment in the current era of de-escalating axillary management

PURPOSE

OSNA is a molecular technique for sentinel lymph node (SN) analysis in breast cancer. Compared to histology, OSNA may yield more (micro)metastases and thereby result in more axillary lymph node dissections or radiotherapy. We investigated whether axillary treatments increase when using OSNA, applying current guidelines for de-escalating axillary management.

METHODS

All patients treated for cT1-3N0 breast cancer in our hospital between December 2013 and February 2016 were included. In 148 prospectively included patients (January 2015-February 2016), SN's were examined with OSNA. In a retrospective cohort of 123 patients (December 2013-December 2014), SN's were examined with conventional histology. Outcomes were: number of macro and micrometastases, amount of patients receiving axillary dissection or irradiation, number of patients receiving adjuvant systemic therapy. Data were analyzed using Mann-Whitney and Pearson Chi-square test. P < 0.05 was considered statistically significant.

RESULTS

230 SN's from 123 patients were examined with conventional histology. 229 SN's from 148 patients were evaluated with OSNA. Amount of macrometastases was equal between groups (histology 17.9% versus OSNA 16.2%, p = 0.715). We found significantly more micrometastases when using OSNA (histology 11.4% versus OSNA 25.0%, p = 0.004). Total number of axillary lymph node dissections was comparable in both groups (histology 12.2%, OSNA 12.2%, p = 0.993), as well as number of axillary radiations (histology 8.9%, OSNA 11.5%, p = 0.493). Also, the number of patients receiving adjuvant systemic therapy was similar between conventional histology and OSNA (histology 53.7% versus OSNA 58.1%, p = 0.462).

CONCLUSION

OSNA analysis for SN in breast cancer is a highly sensitive technique, detecting more micrometastases than standard histology. When applying current guidelines, OSNA analysis does not lead to overtreatment with more axillary dissections or irradiation.

Can Complete Axillary Node Dissection Be Safely Omitted in Patients with Early Breast Cancer When the Sentinel Node Biopsy Is Positive for Malignancy? An Update for Clinical Practice

The sentinel lymph node biopsy (SLNB) has become the new standard-of-care for patients with clinically node-negative invasive breast cancer. The focused examination of fewer lymph nodes in addition to improvements in histopathological and molecular analysis have increased the rate at which micrometastases and isolated tumor cells are identified. We reviewed the literature and summarized the evidence regarding the need for complete axillary lymph node dissection (ALND) following the finding of a positive sentinel node biopsy through the identification of the most important outcomes and evaluation of quality of evidence. The article focuses on the safe omission of complete ALND when the axillary lymph nodes contain macrometastases and provides an overview of the topic primarily based on level 1 evidence derived from randomized clinical trials with a critical appraisal of the ACOSOG Z0011 trial.

Sentinel Lymph Node Evaluation: What the Radiologist Needs to Know

Axillary lymph node status is the single most important prognostic indicator in patients with breast cancer. Axillary lymph node dissection, the traditional method of staging breast cancer, is associated with significant morbidity. Sentinel lymph node biopsy has become standard in patients being treated for breast cancer with clinically negative lymph nodes. There is considerable variation in the medical literature regarding technical approaches to sentinel lymph node biopsy in patients with breast cancer. The purpose of this article is to describe our preferred approaches to sentinel lymph node biopsy with a review of the literature.

Is sentinel lymph node biopsy indicated in patients with a diagnosis of ductal carcinoma in situ? A systematic literature review and meta-analysis

BACKGROUND

Recent discussion has suggested that some cases of ductal carcinoma in situ (DCIS) with high risk of invasive disease may require sentinel lymph node biopsy (SLNB).

METHODS

Systematic literature review identified 48 studies (9,803 DCIS patients who underwent SLNB). Separate analyses for patients diagnosed preoperatively by core sampling and patients diagnosed postoperatively by specimen pathology were conducted to determine the percentage of patients with axillary nodal involvement. Patient factors were analyzed for associations with risk of nodal involvement.

RESULTS

The mean percentage of positive SLNBs was higher in the preoperative group (5.95% vs 3.02%; P = .0201). Meta-regression analysis showed a direct association with tumor size (P = .0333) and grade (P = .00839) but not median age nor tumor upstage rate.

CONCLUSIONS

The SLNB should be routinely considered in patients with large (>2 cm) high-grade DCIS after a careful multidisciplinary discussion. In the context of breast conserving surgery, the SLNB is not routinely indicated for low- and intermediate-grade DCIS, high-grade DCIS smaller than 2 cm, or pure DCIS diagnosed by definitive surgical excision.

Quantitation of the Regional Lymph Node Metastatic Burden and Prognosis in Malignant Mammary Tumors of Dogs

BACKGROUND

As in women, regional lymph node status impacts survival in dogs with malignant mammary tumors. However, few studies have evaluated regional lymph node metastases in dogs with malignant mammary gland tumors.

OBJECTIVES

To estimate overall survival based on the assessments of the lymph node status and the morphologic and morphometric features in female dogs with malignant mammary gland tumors.

MATERIALS AND METHODS

In total, 178 lymph nodes from 97 female dogs were assessed and reviewed, and after confirmation by immunohistochemistry (IHC), 161 lymph nodes were selected for analysis of metastases. Animals were considered metastasis-free (negative lymph nodes) only after IHC analysis for cytokeratin AE1/AE3. The number of positive lymph nodes, the number of metastatic foci, the maximum diameter and the area of metastasis were analyzed, and estimates of overall survival were made.

RESULTS

Dogs with metastasis had lower mean survival than those with metastasis-free regional lymph nodes, showing a direct relationship between the number of affected lymph nodes and shorter survival. However, histologic analysis of the lymph nodes identified lower survival rates in animals with macrometastases and isolated tumor cells, areas of metastasis >20.11 mm², and metastatic diameters >7.32 mm.

CONCLUSION

The identification of ≥1 lymph nodes positive for metastasis and morphometric characterization of lymphatic metastases indicate the prognostic relevance of lymph nodes status in dogs with mammary tumors.

Towards optimal management of the axilla in the context of a positive sentinel node biopsy in early breast cancer

The sentinel lymph node biopsy (SLNB) was initially pioneered for staging melanoma in 1994 and it has been subsequently validated by several trials, and has become the new standard of care for patients with clinically node negative invasive breast cancer. The focussed examination of fewer lymph nodes in addition to improvements in histopathological and molecular analysis has increased the rate at which micrometastases and isolated tumour cells are identified. In this article we review the literature regarding the optimal management of the axilla when the SLNB is positive for metastatic disease based on level 1 evidence derived from randomised clinical trials.

Prognostic role of micrometastases in sentinel lymph node in patients with invasive breast cancer

BACKGROUND AND PURPOSE OF THE STUDY

Axillary lymph node status at the time of diagnosis remains one of the most important prognostic factors in women with breast cancer. Sentinel lymph node biopsy (SLNB) proved to be a reliable method for the evaluation of axillary nodal status in early-stage invasive breast cancer. The prognostic value and potential therapeutic consequences of SLN micrometastases remains a matter of great debate.

PATIENTS AND METHODS

From January 1998 to March 2011, 1,976 consecutive patients with non-metastatic invasive breast cancer underwent surgical treatment; 1,080 of them (54.6%) underwent SLNB. We collected data regarding demography, preoperative lymphoscintigraphy, type of surgery, histopathologic and immunohistochemical features and adjuvant treatment.

MAIN FINDINGS

A mean number of 2.1 ± 1.4 (range 1-13) SLN per patient were collected, a total of 2,294 nodes. SLNs were macrometastatic in 16.7% of patients and micrometastatic in 3.3%. Among the patients with positive SLN 93.6% underwent complete ALND. The overall survival (OS) and disease-free survival (DFS) of 72 patients with micrometastases in SLN at 60 months was 100%, similar to patients with negative SLN (98.7%), quite different from the DFS of N1-N3 patients (85.8%). Statistically significant differences in OS and DFS were observed between patients with N1mi and the group with N1-N3 sentinel node (p < 0.001 and p = 0.04) and also between patients with negative SLN and those with macrometastatic SLN (p < 0.001 for both).

CONCLUSION

SLN micrometastases could represents an epiphenomenon of peritumoral lymphovascular invasion which impacts independently on the survival of patients with invasive breast cancer.

Bilateral ultrastaging of sentinel lymph node in cervical cancer: Lowering the false-negative rate and improving the detection of micrometastasis

OBJECTIVE

To evaluate the sensitivity of sentinel node (SN) ultrastaging and to define parameters that may reduce the overall false-negative rate in women with early-stage cervical cancer.

METHODS

We analyzed data from a large retrospective multicenter cohort group with FIGO stages IA-IIB cervical cancer in whom at least one SN was identified and systematic pelvic lymphadenectomy was uniformly performed. All who were SN negative by initial evaluation were subjected to ultrastaging.

RESULTS

In all, 645 patients were evaluable. SN were detected bilaterally in 72% of cases and unilaterally in 28%. Patients with optimal bilateral SN detection were significantly more likely to have any metastasis detected (33.3% vs. 19.2%; P<0.001) as well as micrometastasis detected in their SN (39.6% vs. 11.4%). SN ultrastaging resulted in a low overall false-negative rate of 2.8% (whole group) and an even lower false-negative rate of 1.3% for patients with optimal bilateral mapping. Patients with false-negative SN after ultrastaging had a higher prevalence of LVSI and more frequent unilateral SN detection. Sensitivity of SN ultrastaging was 91% (95% CI: 86%-95%) for the whole group and 97% (95% CI: 91%-99%) in the subgroup with bilateral SN detection.

CONCLUSION

These data confirm previous observations that optimal bilateral SN detection substantially decreases the false negative rate of SN ultrastaging and increases detection of micrometastasis. In patients with bilateral SN detection, the sensitivity of SN ultrastaging is not reduced in more advanced stages of the disease. SN mapping and ultrastaging should become standard practice in the surgical management of early-stage cervical cancer.

The Predictive Value of Micrometastasis in Nonsentinel Lymph Nodes

The rate of micrometastatic disease (MMD) to nonsentinel lymph nodes (NSLNs) has been shown to vary considerably in the literature. We identified patients with breast cancer with MMD (N1mi) and measured the incidence of NSLN involvement. We then compared these patients with those who had no metastasis to the SLN (N0) and those who had macrometastasis to the SLN (N2) in an attempt to better understand the behavior of patients with N1mi positivity. A retrospective analysis was conducted on 574 patients with invasive breast cancer between January 2000 and December 2007. Patients were stratified into three groups: no metastasis (N0), MMD (N1mi), and macrometastasis (N2). Chi square analysis and logistic regression models using SPSS software were applied to determine significance between groups. MMD rate was 7.7 per cent (44 of 574). Of this subset of patients, 33 underwent completion axillary dissection, and only two were found to have NSLN-positive disease. Statistical significance was achieved for NSLN positivity when comparing all three nodal groups against one another (χ22,572 = 337.084, P = 0.000). Logistic regression showed multifocality and lymphovascular invasion to be significant predictors of NSLN metastasis. NSLN positivity in patients with MMD acts similarly to node-positive disease and therefore cannot completely exclude axillary dissection from therapeutic algorithm.

Prognostic studies of canine and feline mammary tumours: the need for standardized procedures

For several years, veterinary oncologists have been struggling with the prognosis of mammary tumours in dogs and cats. Translation of tumour characteristics into prognostic information is an invaluable tool for the use of the most appropriate therapies, as well as for planning innovative therapeutic trials. Moreover, canine and feline spontaneous mammary gland tumours are good models for the study of human breast cancer. Collecting and interpreting information regarding the prognosis of canine and feline mammary tumours is difficult due to the fact that different methods have been applied to study various components and characteristics. This review identifies some of the challenges of prognostic studies of spontaneous canine and feline mammary tumours and suggests standardized procedures to overcome these challenges and facilitate reproducibility and assessment of results.

Prognostic significance of low volume sentinel lymph node disease in early-stage cervical cancer

OBJECTIVE

Evaluate prognostic significance of low volume disease detected in sentinel nodes (SN) of patients with early stages cervical cancer. Although pathologic ultrastaging of SN allows for identification of low volume disease, including micro-metastasis and isolated tumor cells (ITC), in up to 15% of cases, prognostic significance of these findings is unknown.

METHODS

A total of 645 records from 8 centers were retrospectively reviewed. Enrolled in our study were patients with early-stage cervical cancer who had undergone surgical treatment including SN biopsy followed by pelvic lymphadenectomy and pathologic ultrastaging of SN.

RESULTS

Macrometastasis, micrometastasis, and ITC were detected by SN ultrastaging in 14.7%, 10.1%, and 4.5% patients respectively. False negativity of SN ultrastaging reached 2.8%. The presence of ITC was not associated with significant risk, both for recurrence free survival and overall survival. Overall survival was significantly reduced in patients with macrometastasis and micrometastasis; hazard ratio for overall survival reached 6.85 (95% CI, 2.59-18.05) and 6.86 (95% CI, 2.09-22.61) respectively. Presence of micrometastasis was an independent prognostic factor for overall survival in a multivariable model.

CONCLUSION

Presence of micrometastasis in SN in patients with early stage cervical cancer was associated with significant reduction of overall survival, which was equivalent to patients with macrometastasis. No prognostic significance was found for ITC. These data highlight the importance of SN biopsy and pathologic ultrastaging for the management of cervical cancer.

High rate of solitary sentinel node metastases identification by fluorescence-guided lymphatic imaging in breast cancer

BACKGROUND

The lymph node status was shown to be an important prognostic factor for breast cancer, but controversial issues remain. There has been increased focus on optimizing the visualization of lymph nodes for an accurate and selective approach to axillary lymph nodes. Fluorescence-guided lymphatic imaging is a potential candidate for further research on remaining controversies.

METHODS

Forty-seven patients were subject to injection of indocyanine green for navigation to the SLN based on fluorescent dye retention detection. In two groups, patients either received intended axillary lymph node dissection (ALND) and sentinel lymph node biopsy (SLNB) for superstaging or isolated SLNB for minimal-invasive staging. The prospective study was designed to evaluate the technical feasibility with focus on solitary positive SLN.

RESULTS

Visualization of lymphatic vessels with bright fluorescence of the SLN was feasible in 46 of 47 patients. Eighteen of 19 nodal positive patients were correctly identified with a sensitivity of 94.7% in all patients after ALND. After immunohistochemistry, in 19 of 25 overall nodal positive patients (76%) the SLN was the only positive lymph node.

CONCLUSION

Fluorescence-guided imaging using fluorescence retention detection allows transcutaneous navigation with a high rate of solitary positive SLN identification as an alternative technique for further research.

Sentinel lymph node micrometastasis in human breast cancer: an update

INTRODUCTION

The advent of sentinel lymph node biopsy (SLNB) and advances in histopathological and molecular analysis techniques have been associated with an increase in micrometastasis (MM) detection rate. However, the clinical significance of sentinel lymph node micrometastasis (SLN MM) continues to be a subject of much debate. In this article we review the literature concerning SLN MM, with particular emphasis on the prognostic significance of SLN MM. The controversies regarding histopathological assessment, clinical relevance and management implications are also discussed.

METHODS

Literature review facilitated by Medline and PubMed databases. Cross referencing of the obtained articles was used to identify other relevant studies.

RESULTS

Published studies have reported divergent and rather conflicting results regarding the clinical significance and implications of axillary lymph node (ALN) MM in general and SLN MM in particular. Some earlier studies demonstrated no associations, however most recent studies have found SLN MM to be an indicator of poorer prognosis and to be associated with non-SLN involvement. The use of adjuvant chemotherapy and/or hormonal manipulation therapy is associated with an improved survival in patients with SLN MM. Complete ALND may be safely omitted provided that adjuvant systemic therapy recommendations are equal to patients with node-positive disease. However, optimal management of SLN MM is yet to conclude. Furthermore, the identification of MM remains largely dependent on the analytical technique employed and the use of immunohistochemistry (IHC) increases the detection rate of SLN MM. Discrepancies in the histopathological interpretation of TNM classification of SLN tumour burden do exist. Published studies were non-randomized and have significant limitations including a small sample size, limited follow-up period, and lack of standardization and reproducibility of pathological examination of the SLN.

CONCLUSION

Patients with SLN MM have a poorer prognosis than those who are SLN negative. Therapeutic recommendations regarding patients with SLN MM should be taken in the context of multidisciplinary team setting and in selected cases of SLN MM, complete ALND may be safely omitted. A better reproducibility of pathological interpretation of the TNM classification is required so that future therapeutic guidelines can be applied without confusion.

Stage migration after introduction of sentinel lymph node dissection in breast cancer treatment in Denmark: a nationwide study

PURPOSE

To estimate the size and therapeutic consequences of stage migration after introduction of sentinel lymph node dissection (SLND) in breast cancer treatment in Denmark.

PATIENTS AND METHODS

We compared the distribution of lymph node metastases in breast cancer patients operated in 1993-1996 and 2005-2008; before and after introducing SLND. The study was based on data from the national Danish Breast Cancer Cooperative Group (DBCG) database.

RESULTS

We included 24,051 patients in the study; 10,231 patients from the first period and 13,820 from the second period. The proportion of patients having macrometastases was not significantly different in the two periods, whereas the proportion of patients with micrometastases increased from 5.1% to 9.0% (P<0.0001). However, this only resulted in an estimated change, from 7.8% to 8.8%, in the proportion of patients offered adjuvant systemic treatment due to positive nodal status as the only high-risk criterion, when using today's criteria for risk-allocation. In addition, we found that negative hormone receptor status was associated to negative nodal status when adjusted for confounders (odds ratios (OR) 0.83, P<0.0001).

CONCLUSION

Introduction of SLND in breast cancer treatment in Denmark has resulted in a stage migration on 4% due to identification of more micrometastases. However, this stage migration has only minor impact on patients offered adjuvant systemic treatment because nodal status today is less important in risk-allocation.

Clinical importance of micrometastasis in sentinel lymph nodes

INTRODUCTION

We evaluated the incidence of micrometastasis and nonsentinel lymph node metastasis as well as local and axillary recurrence rates after level I-II axillary lymph node dissection.

MATERIALS AND METHODS

Patients (n=760) with early-stage breast cancer underwent sentinel lymph node biopsy, and 45 patients (6.0%) with micrometastasis (0.2-2.0mm) were included in this study. Data concerning tumor, patients' characteristics and adjuvant treatments were recorded.

RESULTS

The median age was 46 (26-67) years, median breast tumor size was 20 (1-50) mm, and median number of excised sentinel lymph nodes were 2 (1-5). All patients with micrometastasis underwent further level I-II axillary lymph node dissection. Eleven of 45 (24.4%) patients with micrometastasis in their sentinel lymph node biopsy had nonsentinel lymph node metastasis after an axillary lymph node dissection. There was no factor related to nonsentinel lymph node metastasis. Stage migration occurred in 4 of 45 patients (8.8%) due to the detection of micrometastases or macrometastases in nonsentinel lymph nodes.

DISCUSSION

The classical treatment after detection of micrometastasis in sentinel lymph nodes is further axillary dissection. However, nonrandomized, nonprospective studies with 4-5 years follow up showed 0.6% axillary recurrence without further axillary lymph node dissection, although we still need the results of randomized controlled studies.

Current status of sentinel lymph-node biopsy in patients with breast cancer

Axillary node status is the most important prognostic indicator for patients with invasive breast cancer. Sentinel lymph-node biopsy (SLNB) is widely accepted and the preferred procedure for identifying lymph-node metastasis. SLNB allows focused excision and pathological examination of the most likely axillary lymph nodes to receive tumor metastases while avoiding morbidities associated with complete axillary nodal dissection. Since its introduction in the early 1990s, the process of SLNB has undergone continual modification and refinement; however, the procedure varies between institutions and controversies remain. In this review, we examine the technical issues that influence the success of lymph node mapping, discuss the controversies, and summarize the indications and contraindications for axillary node mapping and biopsy in clinical practice.

Establishing axillary Sentinel Lymph Node Biopsy (SLNB) for early breast cancer in the United Kingdom: a survey of the national training program

INTRODUCTION

The UK National training programme (NEWSTART) for SLNB in breast cancer was established in 2004, aimed at providing structured, standardised training with a focus on multidisciplinary team (MDT) delivery.

METHODOLOGY

A questionnaire was devised and after approval by the Association of Breast Surgeons (ABS) executive committee they were sent to all full members of the ABS.

RESULTS

Most (97%) of breast surgeons are convinced by the evidence for SLNB as standard of care for early breast cancer. 64% use SLNB to stage clinically node negative patients, of whom 23% use it as a standalone procedure. 38% of surgeons were dissatisfied with the time it takes to complete the in house training, and 87% with the time it takes to complete the validation phase. Logistical and funding issues were the main problems cited. The majority of surgeons (86%) use the recommended combined technique, with 47% continuing to use the dual localisation method. 14% use either blue dye or isotope alone, without scintiscan. Only 10% offer intra operative diagnosis, of which the majority (6%) use touch imprint cytology. 31% included their results in their most recent surgical appraisal.

CONCLUSIONS

The majority of breast surgeons in the UK are convinced by the evidence for SLNB, and most use SLNB in their practice for staging. Reasons for not conducting SLNB are logistical rather than lack of belief in the procedure. The majority of respondents completed their training within the anticipated time line. The majority of centres do not perform intra-operative assessment.

ICG fluorescence-guided sentinel node biopsy for axillary nodal staging in breast cancer

BACKGROUND

Sentinel lymph node (SLN) biopsy is a selective approach to axillary staging of breast cancer with reduced morbidity. Current detection methods including radioisotope and blue dye show good results but some drawbacks are remaining. Indocyanine green (ICG) fluorescence detection was evaluated as a new method for SLN biopsy in breast cancer allowing both transcutaneous visualization of lymphatic vessels and intraoperative identification of SLN.

METHODS

Forty-three women with clinically node negative breast cancer received subareolar injection of ICG for fluorescence detection of SLN. All patients underwent either planned axillary lymph node dissection (ALND) with SLN biopsy or selective SLN biopsy to determine need for ALND. Clinical feasibility, detection rate, sensitivity, and axillary recurrence after isolated SLN biopsy were analyzed.

RESULTS

Overall ICG fluorescence imaging identified 2.0 SLN in average in 42 of 43 patients (detection rate: 97.7%). Metastatic involvement of the SLN was found in 17 of 18 nodal positive patients by conventional histopathology (sensitivity: 94.4%). Immunohistochemistry revealed isolated tumor cells in five further cases. There was only one false-negative case in 43 patients (5.6%). In 17 of 23 overall nodal positive patients, the SLN was the only positive lymph node. After a median follow-up of 4.7 years none of the patients presented with axillary recurrence.

CONCLUSION

ICG fluorescence imaging is a new method for SLN biopsy in breast cancer with acceptable sensitivity and specificity comparable to conventional methods. One advantage of this technique is that it allows transcutaneous visualization of lymphatic vessels and intraoperative lymph node detection without radioisotope.

Identification and biologic significance of micrometastases in axillary lymph nodes in patients with invasive breast cancer

CONTEXT

The presence or absence of metastases in axillary lymph nodes is one of the most important prognostic factors for patients with breast cancer. During the past decade sentinel lymph node (SLN) biopsy has been increasingly adopted as a minimally invasive staging alternative to complete axillary node dissection.

OBJECTIVE

Sentinel lymph nodes are more likely to contain metastases than non-SLNs. In routine clinical practice SLNs are assessed by diverse methodologies including multiple sectioning, immunohistochemical staining, and molecular diagnostic tests. Despite the lack of standard histopathologic protocols during the years detailed evaluation of SLNs has resulted in an increased detection of small (micro) metastases.

DATA SOURCES

Breast cancer with micrometastases constitutes a heterogenous group of tumors with variable clinical outcome regarding the risk of additional metastases in the remaining axillary lymph nodes and to patients' survival.

CONCLUSION

The clinical significance of micrometastases has been subject to great controversy in patients with breast cancer. In this review we highlight controversies regarding micrometastases especially in relation to SLNs.