Safety of avoiding routine use of axillary dissection in early stage breast cancer: a systematic review

Sentinel Lymph Node Biopsy vs. Axillary Lymph Node Dissection for Early-Stage Breast Cancer and Sentinel Lymph Node Metastasis: An Updated Systematic Review and Meta-Analysis With Special Focus on Locoregional Recurrence and Regional Node Irradiation

Background

The management of early breast cancer patients with metastatic sentinel lymph nodes (SLNs) remains a critical decision point in balancing survival outcomes with surgical morbidities. This study addresses whether sentinel lymph node biopsy (SLNB) with or without regional node irradiation (RNI) can offer comparable survival outcomes to axillary lymph node dissection (ALND).

Objectives

To evaluate overall survival (OS), disease-free survival (DFS), locoregional recurrence (LRR), and mortality outcomes of SLNB (with or without RNI) compared with ALND in patients with metastasis-positive SLNs.

Design

We have performed an updated meta-analysis of randomized controlled trials (RCTs) comparing SLNB alone or with RNI vs. ALND for early breast cancer patients with metastatic SLNs.

Data Sources and Methods

Eligibility criteria included RCTs comparing SLNB ± RNI vs ALND for metastasis-positive SLN. PubMed, EMBASE, the Cochrane library, and online registers were searched for articles comparing SLNB alone vs. ALND for metastasis-positive SLN. Articles were evaluated for risk of bias using Cochrane's revised tool (RoB). The main summary measures using the random effects model were hazard ratio and risk ratio.

Results

Seven RCTs were included in the meta-analysis. Overall survival and DFS were superior in the SLNB group compared to the ALND group. Locoregional recurrence and mortality were comparable between both the groups. After stratifying RCTs with regards to adjuvant RNI, these parameters were still comparable to ALND.

Conclusion

This meta-analysis suggests that SLNB, with or without RNI, offers comparable OS and DFS to ALND for early breast cancer patients with metastasis-positive SLNs. However, the inclusion of studies that did not differentiate between micrometastases and macrometastases may introduce bias, particularly when assessing the impact of RNI. The role of RNI remains debated specially in those with macrometastases, and future research should focus on stratified analyses to clarify this. While SLNB represents a viable alternative to ALND, further trials are needed to define the optimal role in subgroups with high-risk tumor biology.

Predicting axillary lymph node metastasis in breast cancer based on ultrasound radiofrequency time-series analysis

BACKGROUND

The status of axillary lymph nodes (ALN) plays a critical role in the management of patients with breast cancer. It is an urgent demand to develop highly accurate, non-invasive methods for predicting ALN status.

PURPOSE

To evaluate the efficacy of ultrasound radiofrequency (URF) time-series parameters, in combination with clinical data, in predicting ALN metastasis in patients with breast cancer.

MATERIAL AND METHODS

We prospectively gathered clinicopathologic and ultrasonic data from patients diagnosed with breast cancer. Various machine-learning (ML) models were developed using all available features to determine the most efficient diagnostic model. Subsequently, distinct prediction models were created using the optimal ML model, and their diagnostic performances were evaluated and compared.

RESULTS

The study encompassed 240 patients, of whom 88 had lymph node metastases. A leave-one-out cross-validation (LOOCV) method was used to split the entire dataset into training and testing subsets. The random forest ML model outperformed the other algorithms, with an area under the curve (AUC) of 0.92. Prediction models based on clinical, ultrasonic, URF parameters, clinical + ultrasonic, clinical + URF, and ultrasonic + URF parameters had AUCs of 0.56, 0.79, 0.78, 0.90, 0.80, and 0.84, respectively, in the testing set. The comprehensive diagnostic model (clinical + ultrasonic + URF parameters) demonstrated strong diagnostic capability, with an AUC of 0.94 in the testing set, exceeding any single prediction model.

CONCLUSION

The combined model (clinical + ultrasonic + URF parameters) could be used preoperatively to predict lymph node status, offering valuable input for the design of individualized surgical approaches.

Indocyanine green fluorescence versus blue dye, technetium-99M, and the dual-marker combination of technetium-99M + blue dye for sentinel lymph node detection in early breast cancer-meta-analysis including consistency analysis

BACKGROUND

Axillary sentinel lymph node biopsies are standard of care in patients with breast cancer and no clinically apparent metastases. Traditionally, technetium-99m, blue dye, or both have been used to identify sentinel lymph nodes. However, blue dyes miss up to 40% of sentinel lymph nodes, while technetium-99m use is complex, costly, and exposes patients to radiation. Over the past decade, studies have consistently found the biologically inert fluorescent indocyanine green to be 95% to 100% sensitive in detecting breast cancer sentinel lymph nodes, yet indocyanine green remains infrequently used.

METHODS

We conducted an extensive meta-analysis comparing indocyanine green against blue dye, technetium-99m, and the dual-marker combination of technetium-99m + BD. Unlike prior meta-analyses that only assessed either per-case or per-node sentinel lymph node detection, we analyzed the following 5 metrics: per-case and per-node sentinel lymph node detection and metastasis-positive sentinel lymph node sensitivity, and mean number of sentinel lymph nodes/case. We further examined the consistency and magnitude of between-study superiority and statistically significant within-study superiority of each marker against others.

RESULTS

For every metric and analysis approach, indocyanine green was clearly superior to blue dye and at least non-inferior, if not superior, to technetium-99m and technetium-99m + blue dye. Assessing the consistency of superiority by at least 2.0%, indocyanine green was superior to blue dye 73 times versus 1, to technetium-99m 42 times versus 9, and to technetium-99m + blue dye 6 times versus 0. Within-study statistically significant differences favored indocyanine green over blue dye 29 times versus 0 and over technetium-99m 11 times versus 2.

DISCUSSION

For sentinel lymph node detection in patients with breast cancer with no clinically apparent metastases, indocyanine green is clearly and consistently superior to blue dye and either non-inferior or superior to technetium-99m and technetium-99m + blue dye.

Axillary management in patients with clinical node-negative early breast cancer and positive sentinel lymph node: a systematic review and meta-analysis

Background

The omission of axillary lymph node dissection (ALND) or axillary radiation (AxRT) remains controversial in patients with clinical node-negative early breast cancer and a positive sentinel lymph node.

Methods

We conducted a comprehensive review by searching PubMed, Embase, Web of Science, and Cochrane databases (up to November 2023). Our primary outcomes were overall survival (OS), disease-free survival (DFS), locoregional recurrence (LRR), and axillary recurrence (AR).

Results

We included 26 studies encompassing 145,548 women with clinical node-negative early breast cancer and positive sentinel lymph node. Pooled data revealed no significant differences between ALND and sentinel lymph node biopsy (SLNB) alone in terms of OS (hazard ratio [HR]0.99, 95% confidence interval [CI] 0.91-1.08, p=0.84), DFS (HR 1.04, 95% CI 0.90-1.19, p=0.61), LRR (HR 0.76, 95% CI 0.45-1.20, p=0.31), and AR (HR 1.01, 95% CI 0.99-1.03, p=0.35). Similarly, no significant differences were observed between AxRT and SLNB alone for OS (HR 0.57, 95% CI 0.32-1.02, p=0.06) and DFS (HR 0.52, 95% CI 0.26-1.05, p=0.07). When comparing AxRT and ALND, a trend towards higher OS was observed the AxRT group (HR 0.08, 95% CI 0.67-1.15), but the difference did not reach statistical significance (p=0.35, I2 = 0%). Additionally, no significant differences significance observed for DFS or AR (p=0.13 and p=0.73, respectively) between the AxRT and ALND groups.

Conclusion

Our findings suggest that survival and recurrence rates are not inferior in patients with clinical node-negative early breast cancer and a positive sentinel lymph node who receive SLNB alone compared to those undergoing ALND or AxRT.

10-Year axillary recurrence in the RACS SNAC1 randomised trial of sentinel lymph node-based management versus routine axillary lymph node dissection

BACKGROUND

Sentinel node-based management (SNBM) is the international standard of care for early breast cancer that is clinically node-negative based on randomised trials comparing it with axillary lymph node dissection (ALND) and reporting similar rates of axillary recurrence (AR) without distant disease. We report all ARs, overall survival, and breast cancer-specific survival at 10-years in SNAC1.

METHODS

1.088 women with clinically node-negative, unifocal breast cancers 3 cm or less in diameter were randomly assigned to either SNBM with ALND if the sentinel node (SN) was positive, or to SN biopsy followed by ALND regardless of SN involvement.

RESULTS

First ARs were more frequent in those assigned SNBM rather than ALND (11 events, cumulative risk at 10-years 1·85%, 95% CI 0·95-3.27% versus 2 events, 0·37%, 95% CI 0·08-1·26%; HR 5·47, 95% CI 1·21-24·63; p = 0·013). Disease-free survival, breast cancer-specific survival, and overall survival were similar in those assigned SNBM versus ALND. Lymphovascular invasion was an independent predictor of AR (HR 6·6, 95% CI 2·25-19·36, p < 0·001).

CONCLUSION

First ARs were more frequent with SNBM than ALND in women with small, unifocal breast cancers when all first axillary events were considered. We recommend that studies of axillary treatment should report all ARs to give an accurate indication of treatment effects. The absolute frequency of AR was low in women meeting our eligibility criteria, and SNBM should remain the treatment of choice in this group. However, for those with higher-risk breast cancers, further study is needed because the estimated risk of AR might alter their choice of axillary surgery.

Omitting SLNB in Breast Cancer: Is a Nomogram the Answer?

BACKGROUNDS

Sentinel lymph node biopsy (SLNB) is standard care as a staging procedure in patients with invasive breast cancer. The axillary recurrence rate, even after positive SLNB, is low. This raises serious doubts regarding the clinical value of SLNB in early breast cancer. The purpose of this study is to select patients with low suspected axillary burden in whom SLNB might be omitted.

PATIENTS AND METHODS

We retrospectively analyzed 2015 primary breast cancer patients between 2007 and 2015, with 982 patients allocated to the training and 961 to the validation cohort. Variables associated with nodal disease were analyzed and used to build a nomogram for predicting nodal disease.

RESULTS

A total of 32.8% of patients had macrometastatic disease. A predictive model was constructed based on age, cN0, morphology, grade, multifocality, and tumor size with an area under the receiver operating characteristic curve (AUC) of 0.83. Considering a false-negative rate of 5%, 32.8% of patients could be spared axillary surgery. In a subanalysis of patients with relatively favorable characteristics, 26.8% had less than 5% chance of macrometastases.

CONCLUSIONS

We present a model with excellent predictive value that can select one-third of patients in whom SLNB is deemed not necessary because of less than 5% chance of nodal involvement. Whether missing 1 in 20 patients with macrometastatic disease is worthwhile balanced against preventing side-effects of the SLN procedure remains to be established. A number of ongoing large prospective trials evaluating the outcome of omitting SLNB are awaited. Meanwhile, this nomogram may be used for individual decision-making.

Omitting completion axillary lymph node dissection after detection of sentinel node micrometastases in breast cancer: first results from the prospective SENOMIC trial

BACKGROUND

Completion axillary lymph node dissection has been abandoned widely among patients with breast cancer and sentinel lymph node micrometastases, based on evidence from prospective RCTs. Inclusion in these trials has been subject to selection bias, with patients undergoing mastectomy being under-represented. The aim of the SENOMIC (omission of axillary lymph node dissection in SENtinel NOde MICrometases) trial was to confirm the safety of omission of axillary lymph node dissection in patients with breast cancer and sentinel lymph node micrometastases, and including patients undergoing mastectomy.

METHODS

The prospective SENOMIC multicentre cohort trial enrolled patients with breast cancer and sentinel lymph node micrometastases who had breast-conserving surgery or mastectomy at one of 23 Swedish hospitals between October 2013 and March 2017. No completion axillary lymph node dissection was performed. The primary endpoint was event-free survival, with a trial accrual target of 452 patients. Survival proportions were based on Kaplan-Meier survival estimates.

RESULTS

The trial included 566 patients. Median follow-up was 38 (range 7-67) months. The 3-year event-free survival rate was 96.2 per cent, based on 26 reported breast cancer recurrences, including five isolated axillary recurrences. The unadjusted 3-year event-free survival rate was higher than anticipated, but differed between patients who had mastectomy and those who underwent breast-conserving surgery (93.8 versus 97.8 per cent respectively; P = 0.011). Patients who underwent mastectomy had significantly worse tumour characteristics. On univariable Cox proportional hazards regression analysis, patients who had mastectomy without adjuvant radiotherapy had a significantly higher risk of recurrence than those who underwent breast-conserving surgery (hazard ratio 2.91, 95 per cent c.i. 1.25 to 6.75).

CONCLUSION

After 3 years, event-free survival was excellent in patients with breast cancer and sentinel node micrometastases despite omission of axillary lymph node dissection. Long-term follow-up and continued enrolment of patients having mastectomy, especially those not receiving adjuvant radiotherapy, are of utmost importance.

Quantifying the Mitigating Effects of Whole-Breast Radiotherapy and Systemic Treatments on Regional Recurrence Incidence Among Breast Cancer Patients

Background

Despite the potential for residual lymph node metastases after a negative or positive sentinel lymph node biopsy (SLNB), breast cancer patients rarely experience regional recurrences (RRs). This study aimed to quantify the effects of nonsurgical treatments on RR incidence among SLNB-negative (SLNB N0) breast cancer patients.

Methods

All primary SLNB N0-staged breast cancer patients with a diagnosis between 2005 and 2008 and 5-year follow-up data on recurrences were selected from the Netherlands Cancer Registry. The cumulative incidence function (CIF) for RR was calculated as the first event at 5 years, taking into account any other first-event (local or distant recurrence, contralateral breast cancer, or death) as competing risk. Cox regression analysis was used to model the cause-specific hazard of RR developing as the first event to quantify the effect of adjuvant systemic therapy and whole-breast radiotherapy (RT) on RR incidence at 5 years.

Results

The study included 13,512 patients. Of these patients, 162 experienced an RR. The CIF of RR at 5 years was 1.3% (95% confidence interval [CI], 1.1–1.5%), whereas the CIFs for death and other events were 4.4% and 9.5%, respectively. Cox regression analysis showed hazard ratios (HRs) of 0.46 (95% CI 0.33–0.64), 0.31 (95% CI 0.18–0.55), and 0.40 (95% CI 0.24–0.67) respectively for patients treated by RT as a routine part of breast-conserving therapy (BCT), chemotherapy, and hormonal therapy.

Conclusion

RT as routine part of BCT, chemotherapy, and hormonal therapy independently exerted a mitigating effect on the risk for the development of RR. The three methods at least halved the risk.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08356-2) contains supplementary material, which is available to authorized users.

The Adventure of Axillary Treatment in Early Stage Breast Cancer

Axillary lymph node dissection (ALND) which was an essential part of breast cancer treatment and the gold standard in evaluation of the status of axillary lymph node had notorious with increased arm morbidity and reduction of quality of life. Sentinel lymph node biopsy (SLNB) accurately stages the axilla in early breast cancer and ALND is omitted in SLNB negative patients. In patients with positive SLNB the omission of ALND with or without replacement of axillary radiotherapy has also been recommended by guidelines. The neoadjuvant chemotherapy (NAC) which has been increasingly used for large breast cancers to downstage the tumours for allowing breast conserving surgery and decreasing mastectomy rate has also been used in axillary node positive patients to reduce the need for ALND. The issues surrounding the treatment of axilla in patients treated with NAC; application and false negative rate of SLNB, number of identified sentinel lymph nodes, and axillary radiotherapy instead of ALND are currently the discussed and practiced hot topics. The quests for decreasing arm morbidity without compromising outcome in breast cancer treatment which have begun with the invention of SLNB continue for axilla conserving surgery. This article reviews the adventure of axillary treatment in breast cancer patients treated with or without NAC.

Factors that affect the false negative rate of sentinel lymph node mapping with methylene blue dye alone in breast cancer

Objective

This study aimed to investigate the clinicopathological factors of the false negative rate (FNR) and accuracy of sentinel lymph node biopsy (SLNB) mapping with 1% methylene blue dye (MBD) alone, and to examine how to reduce the FNR in patients with breast cancer.

Methods

A total of 365 patients with invasive breast carcinoma who received axillary lymph node dissection after SLNB were retrospectively analyzed. SLNB was performed with 2 to 5 mL of 1% MBD. We studied the clinicopathological factors that could affect the FNR of SLNB.

Results

The identification rate of sentinel lymph nodes (SLNs) was 98.3% (359/365) and the FNR of SLNB was 10.4% (16/154). Multivariate analysis showed that the number of dissected SLNs and metastatic lymph nodes were independent predictive factors for the FNR of SLNB. The FNR in patients with 1, 2, 3, and ≥4 SLNs was 23.53%, 15.79%, 3.85%, and 1.79%, respectively.

Conclusions

SLNB mapping with MBD alone in patients with breast cancer can produce favorable identification rates. The FNR of SLNB decreases as the number of SLNs rises. Because of side effects of searching for additional SLNs and the FNR, removal of three or four SLNs may be appropriate.

Do clinical trials truly mirror their target population? An external validity analysis of national register versus trial data from the Swedish prospective SENOMIC trial on sentinel node micrometastases in breast cancer

Purpose

Increasing evidence suggests that completion axillary lymph node dissection (ALND) may be omitted in breast cancer patients with limited axillary nodal metastases. However, the representativeness of trial participants for the original clinical practice population, and thus, the generalizability of published trials have been questioned. We propose the use of background data from national registers as a means to assess whether trial participants mirror their target population and to strengthen the generalizability and implementation of trial outcomes.

Methods

The Swedish prospective SENOMIC trial, omitting a completion ALND in breast cancer patients with sentinel lymph node micrometastases, reached full target accrual in 2017. To assess the generalizability of trial results for the target population, a comparative analysis of trial participants versus cases reported to the Swedish National Breast Cancer Register (NKBC) was performed.

Results

Comparing 548 trial participants and 1070 NKBC cases, there were no significant differences in age, tumor characteristics, breast surgery, or adjuvant treatment. Only the mean number of sentinel lymph nodes with micrometastasis per individual was lower in trial participants than in register cases (1.06 vs. 1.09, p = 0.037).

Conclusions

Patients included in the SENOMIC trial are acceptably representative of the Swedish breast cancer target population. There were some minor divergences between trial participants and the NKBC population, but taking these into consideration, upcoming trial outcomes should be generalizable to breast cancer patients with micrometastases in their sentinel lymph node biopsy.

Ultrasound-guided immunofunctional photoacoustic imaging for diagnosis of lymph node metastases

Metastases, rather than primary tumors, determine mortality in the majority of cancer patients. A non-invasive immunofunctional imaging method was developed to detect sentinel lymph node (SLN) metastases using ultrasound-guided photoacoustic (USPA) imaging combined with glycol-chitosan-coated gold nanoparticles (GC-AuNPs) as an imaging contrast agent. GC-AuNPs, injected peritumorally into breast tumor-bearing mice, were taken up by immune cells, and subsequently transported to the SLN. Two-dimensional and three-dimensional USPA imaging was used to isolate the signal from GC-AuNP-tagged cells. Volumetric analysis was used to quantify GC-AuNP accumulation in the SLN after cellular uptake and transport by immune cells. The results show that the spatio-temporal distribution of GC-AuNPs in the SLN was affected by the presence of metastases. The parameter describing the spatial distribution of GC-AuNP-tagged cells within the SLN was more than 2-fold lower in metastatic lymph nodes compared with non-metastatic controls. Histological analysis confirmed that the distribution of GC-AuNP-tagged immune cells is changed by the presence of metastatic cells. The USPA immunofunctional imaging successfully distinguished metastatic from non-metastatic lymph nodes using biocompatible nanoparticles. This method could aid physicians in the detection of micrometastases, thus guiding SLN biopsy and avoiding unnecessary biopsy procedures.

Regional Recurrence Risk Following a Negative Sentinel Node Procedure Does Not Approximate the False-Negative Rate of the Sentinel Node Procedure in Breast Cancer Patients Not Receiving Radiotherapy or Systemic Treatment

BACKGROUND

Although the false-negative rate of the sentinel lymph node biopsy (SLNB) in breast cancer patients is 5-7%, reported regional recurrence (RR) rates after negative SLNB are much lower. Adjuvant treatment modalities probably contribute to this discrepancy. This study assessed the 5-year RR risk after a negative SLNB in the subset of patients who underwent breast amputation without radiotherapy or any adjuvant treatment.

METHODS

All patients operated for primary unilateral invasive breast cancer between 2005 and 2008 were identified in the Netherlands Cancer Registry. Patients with a negative SLNB who underwent breast amputation and who were not treated with axillary lymph node dissection, radiotherapy, or any adjuvant systemic treatment were selected. The cumulative 5-year RR rate was estimated by Kaplan-Meier analysis.

RESULTS

A total of 13,452 patients were surgically treated for primary breast cancer and had a negative SLNB, and 2012 patients fulfilled the selection criteria. Thirty-eight RRs occurred during follow-up. Multifocal disease was associated with a higher risk of developing RR (P = 0.04). The median time to RR was 27 months and was significantly shorter in patients with estrogen receptor-negative (ER-) breast cancer (9.5 months; P = 0.003). The 5-year RR rate was 2.4% in the study population compared with 1.1% in the remainder of 11,440 SLNB-negative patients (P = 0.0002).

CONCLUSIONS

Excluding the effect of radiotherapy and systemic treatment resulted in a twofold 5-year RR risk in breast cancer patients with a tumor-free SLNB. This 5-year RR rate was still much lower than the reported false-negative rate of the SLNB procedure.

Positive non-sentinel axillary lymph nodes in breast cancer with 1-2 sentinel lymph node metastases

Recent clinical trials have shown that sentinel lymph node biopsy (SLNB) alone without axillary lymph node dissection (ALND) can offer excellent regional control if there is sentinel lymph nodes (SLN) metastases to 1-2 nodes. This study aimed to explore the predictive factors for non-sentinel lymph node (NSLN) metastasis in breast cancer patients with 1-2 positive SLNs.Patients with breast cancer and 1-2 positive SLN admitted between March 2009 and March 2017 and who underwent ALND after SLN biopsy (SLNB) at Beijing Chaoyang Hospital were analyzed retrospectively. Factors influencing the status of NSLN were studied by univariate and multivariate analysis.Of 1125 patients, 147 patients had SLN metastasis (13.1%) and 119 patients (81.0%) had 1-2 positive SLNs. Among them, 42 patients (35.3%) had NSLN metastasis. The invasive tumor size (P <.001), histological grade (P =.011), lymphovascular invasion (LVI) (P =.006), and over-expression of HER2 (P =.025) significantly correlated with non-SLN metastasis by univariate analysis. LVI (LVI) (P =.007; OR: 4.130; 95% confidence interval [CI]: 1.465-11.641), invasive tumor size (P <.001; OR: 7.176; 95% CI: 2.710-19.002), and HER2 over-expression (P =.006; OR: 5.489; 95% CI: 1.635-18.428) were independently associated with NSLN metastasis by the Logistic regression model. The ROC analysis identified a cut-off point of 26 mm of tumor size (area under the receiver operating characteristic [ROC] curve [AUC] 0.712, CI: 0.614-0.811) was useful for dividing patients with positive SLN (1-2 nodes) into non-SLN-positive and non-SLN-negative groups.For 1-2 positive SLNs of breast cancer, LVI, large invasive tumor size, and HER2 over-expression are independent factors affecting NSLN metastases.

Critical review of axillary recurrence in early breast cancer

Around 2% of early breast cancer cases treated with axillary lymph node dissection (ALND) underwent axillary recurrence (AR) and it has a deleterious effect in prognosis. Different scenarios have incorporated Sentinel Lymph Node (SLN) Biopsy (SLNB) instead of ALND as part of the standard treatment and more effective systemic treatment has also been incorporated in routine management after first curative surgery and after regional recurrence. However, there is concern about the effect of SLNB alone over AR risk and how to predict and treat AR. SLN biopsy (SLNB) has been largely accepted as a valid option for SLN-negative cases, and recent prospective studies have demonstrated that it is also safe for some SLN-positive cases and both scenarios carry low AR rates. Different studies have identified clinicopathological factors related to aggressiveness as well as high-risk molecular signatures can predict the development of locoregional recurrence. Other publications have evaluated factors affecting prognosis after AR and find that time between initial treatment and AR as well as tumor aggressive behavior influence patient survival. Retrospective and prospective studies indicate that treatment of AR should include local and systemic treatment for a limited time.

Breast-conserving surgery followed by whole-breast irradiation offers survival benefits over mastectomy without irradiation

Background

The prognostic equivalence between mastectomy and breast‐conserving surgery (BCS) followed by radiotherapy was shown in pivotal trials conducted decades ago. Since then, detection and treatment of breast cancer have improved substantially and recent retrospective analyses point towards a survival benefit for less extensive breast surgery. Evidence for the association of such survival data with locoregional recurrence rates is largely lacking.

Methods

The Swedish Multicentre Cohort Study prospectively included clinically node‐negative patients with breast cancer who had planned sentinel node biopsy between 2000 and 2004. Axillary lymph node dissection was undertaken only in patients with sentinel node metastases. For the present investigation, adjusted survival analyses were used to compare patients who underwent BCS and postoperative radiotherapy with those who received mastectomy without radiotherapy.

Results

Of 3518 patients in the Swedish Multicentre Cohort Study, 2767 were included in the present analysis; 2338 had BCS with postoperative radiotherapy and 429 had mastectomy without radiotherapy. Median follow‐up was 156 months. BCS followed by whole‐breast irradiation was superior to mastectomy without irradiation in terms of both overall survival (79·5 versus 64·3 per cent respectively at 13 years; P < 0·001) and breast cancer‐specific survival (90·5 versus 84·0 per cent at 13 years; P < 0·001). The local recurrence rate did not differ between the two groups. The axillary recurrence‐free survival rate at 13 years was significantly lower after mastectomy without irradiation (98·3 versus 96·2 per cent; P < 0·001).

Conclusion

The present data support the superiority of BCS with postoperative radiotherapy over mastectomy without radiotherapy. The axillary recurrence rate differed significantly, and could be one contributing factor in a complex explanatory model.

Radiotherapy to lower axilla key?

Axillary staging in breast cancer patients treated with neoadjuvant chemotherapy in two Dutch phase III studies

BACKGROUND

Primary aim of our study was to assess the impact of timing of sentinel node procedure, pre- versus post-neoadjuvant chemotherapy, on final pathologic node-negative rate (pN0) in patients with clinically node-negative (cN0) breast cancer. Secondary endpoint was the usability of the sentinel node procedure in patients with clinically node-positive disease that converted to cN0 after neoadjuvant chemotherapy.

PATIENTS AND METHODS

Patients were enrolled in two sequentially conducted Dutch phase III trials, studying the impact of two neoadjuvant chemotherapy schedules and use of zoledronic acid on complete pathologic response rate. For the present analyses, patients were excluded if they had not undergone surgical axillary staging.

RESULTS

In total 439 patients were included, of whom 230 (52%) had pre-treatment cN0. In this group, pN0 status was seen in 58% (N = 23) of patients with a sentinel node biopsy post-neoadjuvant chemotherapy compared to 51% (N = 83) pre-neoadjuvant chemotherapy, including the axillary lymph node dissection whenever performed. In multivariable analysis, timing of sentinel node procedure (pre- versus post- neoadjuvant chemotherapy) was, however, not significantly associated with final pN0/pN0(i+) status, with an odds ratio of 1.18 (95% CI 0.64 - 2.18) after correction for age, clinical tumor status, histology, grade, hormone- and HER2 receptor. Of patients with clinically node-positive disease only 15% had a final pN0 status, with a false-negative rate of the sentinel node of 30%.

CONCLUSION

In breast cancer patients with cN0 disease, sentinel node procedure performed post-neoadjuvant chemotherapy led to nodal down staging, although not statistically significant after multivariate correction for patient and tumor characteristics.

Secondary node analysis as an indicator for axillary lymphadenectomy in breast cancer patients

INTRODUCTION

Currently, there is no agreement regarding if it would be necessary to perform an axillary lymph node dissection (ALND) in patients who have macrometastases in the sentinel lymph node (SLN). We studied the utility of the secondary node analysis (SN), defined as the following node after the SLN in an anatomical and lymphatic pathway, as a sign of malignant axillary involvement.

METHODS

An observational, retrospective and multicentre study was designed to assess the utility of the SN as a sign of axillary involvement. Among 2273 patients with breast cancer, a valid sample of 283 was obtained representing those who had the SN studied. Main endpoints of our study were: the SLN, the SN and the ALND histological pattern. Sensitivity, specificity and precision of the test were also calculated.

RESULTS

SN test, in cases with positive SLN, has a sensitivity of 61.1%, a specificity of 78.7%, a positive predictive value of 45.8% and a negative predictive value of 87.3% with a precision of 74.7%.

CONCLUSION

The study of the SN together with the technique of the SLN allows a more precise staging of the axillary involvement, in patients with breast cancer, than just the SLN technique.

Sentinel lymph node biopsy in Chinese patients with large operable breast cancer (≥4 cm): A decade's experience from a single institution

BACKGROUND

Performing sentinel lymph node biopsy (SLNB) in patients with large operable breast cancer is still controversial. Our aim is to find whether or not performing SLNB is feasible and safety in Chinese patients with large operable breast cancer.

METHODS

We reviewed the data of patients in our center from 2003 to 2015, a series of 267 patients with large operable breast cancer (≥4 cm) who underwent SLNB were examined. All selected patients recieved preoperative axillary evaluation.

RESULTS

The successful rate for localizing SLNs was 96.3% (257 of 267). 31.1% (78 of 257) patients were found to have positive sentinel lymph nodes (SLN). The median follow-up was 52 months. 2.2% (4 of 179) SLN-negative patients developed axillary recurrence (AR) as first event. The 5-year axillary recurrence free survival in SLN-negative patients was 96.9% (95%CI, 93.8%-100%). Patients with suspicious nodes on ultrasonography (US) (P = 0.16) and undergoing breast conserving therapy (BCT) (P = 0.057) had a higher trend to be associated with AR. The 5-year recurrence free survival (RFS) was 86.1% (95%CI, 80.8%-93.0%) in SLN-negative patients and 76.3% (95%CI, 68.1%-90.1%) in SLN-positive patients (P = 0.246).

CONCLUSIONS

SLNB is feasible and safety in patients with large operable breast cancer who underwent preoperative axillary evaluation.

Survival and axillary recurrence following sentinel node-positive breast cancer without completion axillary lymph node dissection: the randomized controlled SENOMAC trial

Background

The role of axillary lymph node dissection (ALND) has increasingly been called into question among patients with positive sentinel lymph nodes. Two recent trials have failed to show a survival difference in sentinel node-positive breast cancer patients who were randomized either to undergo completion ALND or not. Neither of the trials, however, included breast cancer patients undergoing mastectomy or those with tumors larger than 5 cm, and power was debatable to show a small survival difference.

Methods

The prospective randomized SENOMAC trial includes clinically node-negative breast cancer patients with up to two macrometastases in their sentinel lymph node biopsy. Patients with T1-T3 tumors are eligible as well as patients prior to systemic neoadjuvant therapy. Both breast-conserving surgery and mastectomy, with or without breast reconstruction, are eligible interventions. Patients are randomized 1:1 to either undergo completion ALND or not by a web-based randomization tool. This trial is designed as a non-inferiority study with breast cancer-specific survival at 5 years as the primary endpoint. Target accrual is 3500 patients to achieve 80% power in being able to detect a potential 2.5% deterioration of the breast cancer-specific 5-year survival rate. Follow-up is by annual clinical examination and mammography during 5 years, and additional controls after 10 and 15 years. Secondary endpoints such as arm morbidity and health-related quality of life are measured by questionnaires at 1, 3 and 5 years.

Discussion

Several large subgroups of breast cancer patients, such as patients undergoing mastectomy or those with larger tumors, have not been included in key trials; however, the use of ALND is being questioned even in these groups without the support of high-quality evidence. Therefore, the SENOMAC Trial will investigate the need of completion ALND in case of limited spread to the sentinel lymph nodes not only in patients undergoing any breast surgery, but also in neoadjuvantly treated patients and patients with larger tumors.

Trial registration

NCT 02240472, retrospective registration date September 14, 2015 after trial initiation on January 31, 2015.

Ten-year report on axillary recurrence after negative sentinel node biopsy for breast cancer from the Swedish Multicentre Cohort Study

BACKGROUND

The omission of axillary lymph node dissection (ALND) in patients with breast cancer with a negative finding on sentinel node biopsy (SNB) has reduced arm morbidity substantially. Early follow-up reports have shown the rate of axillary recurrence to be significantly lower than expected, with a median false-negative rate of 7 per cent for SNB. Long-term follow-up is needed as recurrences may develop late.

METHODS

The Swedish Multicentre Cohort Study included 3518 women with breast cancer and a clinically negative axilla, in whom SNB was planned. ALND was performed only in patients with sentinel node metastasis. Twenty-six centres contributed to enrolment between September 2000 and January 2004. The primary endpoint was the axillary recurrence rate and the secondary endpoint was breast cancer-specific survival, calculated using Kaplan-Meier survival estimates.

RESULTS

Some 2216 sentinel node-negative patients with 2237 breast cancers were analysed. The median follow-up time was 126 (range 0-174) months. Isolated axillary recurrence was found in 35 patients (1·6 per cent). High histological grade and multifocal tumours were risk factors for axillary recurrence, whereas the removal of more than two sentinel nodes decreased the risk. Fourteen (40 per cent) of 35 patients died as a consequence of axillary recurrence.

CONCLUSION

The risk of axillary recurrence remains lower than expected after a negative finding on SNB at 10-year follow-up. Axillary recurrences may occur long after primary surgery, and lead to a significant risk of breast cancer death.

Sentinel Lymph Node Biopsy in Breast Cancer: Indications, Contraindications, and Controversies

Axillary lymph node status, a major prognostic factor in early-stage breast cancer, provides information important for individualized surgical treatment. Because imaging techniques have limited sensitivity to detect metastasis in axillary lymph nodes, the axilla must be explored surgically. The histology of all resected nodes at the time of axillary lymph node dissection (ALND) has traditionally been regarded as the most accurate method for assessing metastatic spread of disease to the locoregional lymph nodes. However, ALND may result in lymphedema, nerve injury, shoulder dysfunction, and other short-term and long-term complications limiting functionality and reducing quality of life. Sentinel lymph node biopsy (SLNB) is a less invasive method of assessing nodal involvement. The concept of SLNB is based on the notion that tumors drain in an orderly manner through the lymphatic system. Therefore, the SLN is the first to be affected by metastasis if the tumor has spread, and a tumor-free SLN makes it highly unlikely for other nodes to be affected. Sentinel lymph node biopsy has become the standard of care for primary treatment of early breast cancer and has replaced ALND to stage clinically node-negative patients, thus reducing ALND-associated morbidity. More than 20 years after its introduction, there are still aspects concerning SLNB and ALND that are currently debated. Moreover, SLNB remains an unstandardized procedure surrounded by many unresolved controversies concerning the technique itself. In this article, we review the main indications, contraindications, and controversies of SLNB in breast cancer in the light of the most recent publications.

Factors Associated With Disease Recurrence in Breast Cancer Patients With Negative Sentinel Lymph Node Biopsy

INTRODUCTION

The objective of our study was to assess recurrence after negative sentinel lymph node biopsy (SLNB) and to determine the risk factors related to local and distant recurrence in this group of patients.

MATERIALS AND METHODS

We conducted a prospective observational study from 2006 to 2011. It included 607 patients with early-stage breast cancer and negative SLNB with a 5-year follow-up period.

RESULTS

The disease-free survival rate was 98.5% and 96.5% at 2 and 5 years, respectively. Multivariate analysis identified the following prognostic factors for disease recurrence: tumor necrosis (hazard ratio [HR], 4.89; 95% confidence interval [CI], 1.61-14.89; P = .005), lymphovascular invasion (HR, 3.46; 95% CI, 1.14-10.55; P = .029), T2 tumor size (HR, 4.35; 95% CI, 1.40-13.52; P = .011), and moderate to severe lymphoplasmacytic stromal infiltration (HR, 3.06; 95% CI, 1.18-7.96; P = .022).

CONCLUSION

Recurrence in patients with negative SLNB was satisfactorily low. Nevertheless, determining the prognostic factors related to a greater recurrence rate could help identify high-risk patients and influence systemic adjuvant therapy.

Survival impact and predictive factors of axillary recurrence after sentinel biopsy

BACKGROUND

The rate of axillary recurrence (AR) after sentinel lymph node biopsy is usually low but few studies investigated its impact on survival. Our aim was to determine the rate and predictive factors of AR in a large cohort of breast cancer patients and its impact on survival.

PATIENTS AND METHODS

From 1999 to 2013, 14,095 patients who underwent surgery for clinically N0 previously untreated breast cancer and had sentinel lymph node biopsy were analysed. A simplified score predictive of AR was established.

RESULTS

Median follow-up was 55.2 months. AR was observed in 0.51% of cases, with a median time to onset of 43.4 months. In multivariate analysis, the occurrence of AR was significantly correlated with grade 2 or 3 disease, absence of radiotherapy and tumour subtype (hormonal receptor [HR]- / human estrogen receptor [HER]+). AR rates were 1% for triple-negative tumours, 2.8% for HER2-positive tumours, 0.4% for luminal A tumours, 0.9% for HER2-negative luminal B tumours, and 0.5% for HER2-positive luminal B tumours. A simplified score predictive of the occurrence of AR was established. Patients could be divided into three different score groups (p < 0.0001). In multivariate analysis, overall survival was significantly lower in cases of AR (p < 0.0001), age >50, lymphovascular invasion, grade 3 disease, sentinel node (SN) macrometastases, tumour size >20 mm, absence of chemotherapy and triple-negative phenotype. Survival in patients with AR was significantly lower in case of early-onset (2 years) AR (p = 0.017).

CONCLUSIONS

Isolated AR is more common in Her2-positive/HR-negative triple-negative tumours with a more severe prognosis in triple-negative and Her2-positive/HR-negative tumours, and represents an independent adverse factor justifying an indication for systemic treatment for AR treatment. However, the benefit of any systemic treatment remains to be proven.

Prognostic significance of axillary dissection in breast cancer patients with micrometastases or isolated tumor cells in sentinel nodes: a nationwide study

We estimated the impact of axillary lymph node dissection (ALND) on the risk of axillary recurrence (AR) and overall survival (OS) in breast cancer patients with micrometastases or isolated tumor cells (ITC) in sentinel nodes. We used the Danish Breast Cancer Cooperative Group (DBCG) database to identify patients with micrometastases or ITC in sentinel nodes following surgery for primary breast cancer between 2002 and 2008. A Cox proportional hazard regression model was developed to assess the hazard ratios (HR) for AR and OS between patients with and without ALND. We identified 2074 patients, of which 240 did not undergo further axillary surgery. The 5-year cumulated incidence for AR was 1.58 %. No significant difference in AR was seen between patients with and without ALND. The age adjusted HR for AR if ALND was omitted was 1.79 (95 % CI 0.41-7.80, P = 0.44) in patients with micrometastases and 2.21 (95 % CI 0.54-8.95, P = 0.27), in patients with ITC after a median follow-up of 6 years and 3 months. There was no significant difference in overall survival between patients with and without ALND, when adjusting for age, co-morbidity, tumor size, histology type, malignancy grade, lymphovascular invasion, hormone receptor status, adjuvant systemic treatment and radiotherapy, with a HR for death if ALND was omitted of 1.21 (95 % CI 0.86-1.69, P = 0.27) in patients with micrometastases and 0.96 (95 % CI 0.57-1.62, P = 0.89) in patients with ITC after a medium follow-up on 8 and 5 years. In this nationwide study, we found a low risk of AR on 1.58 % and we did not find a significantly increased risk of AR if ALND was omitted in patients with micrometastases or ITC in sentinel nodes. Furthermore, no significant difference in overall survival was seen between patients with and without ALND when adjusting for adjuvant treatment.

[Regional treatment for axillary lymph node micrometastases of breast cancer]

In patients with breast cancer, axillary lymph node micrometastasis detection has been more frequent with a better definition since the introduction of the sentinel node procedure. In this review, we focus on pN1mi micrometastasis and review the literature in order to determine factors involved in making the decision of a regional treatment.

Risk of node metastasis of sentinel lymph nodes detected in level II/III of the axilla by single-photon emission computed tomography/computed tomography

In breast cancer, single-photon emission computed tomography/computed tomography (SPECT/CT) shows the exact anatomical location of sentinel nodes (SN). SPECT/CT mainly exposes axilla and partly exposes atypical sites of extra-axillary lymphatic drainage. The mechanism of how the atypical hot nodes are involved in lymphatic metastasis was retrospectively investigated in the present study, particularly at the level II/III region. SPECT/CT was performed in 92 clinical stage 0-IIA breast cancer patients. Sentinel lymph nodes are depicted as hot nodes in SPECT/CT. Patients were divided into two groups: With or without hot node in level II/III on SPECT/CT. The existence of metastasis in level II/III was investigated and the risk factors were identified. A total of 12 patients were sentinel lymph node biopsy metastasis positive and axillary lymph node dissection (ALND) was performed. These patients were divided into two groups: With and without SN in level II/III, and nodes in level II/III were pathologically proven. In 11 of the 92 patients, hot nodes were detected in level II/III. There was a significant difference in node metastasis depending on whether there were hot nodes in level II/III (P=0.0319). Multivariate analysis indicated that the hot nodes in level II/III and lymphatic invasion were independent factors associated with node metastasis. There were 12 SN-positive patients followed by ALND. In four of the 12 patients, hot nodes were observed in level II/III. Two of the four patients with hot nodes depicted by SPECT/CT and metastatic nodes were pathologically evident in the same lesion. Therefore, the present study indicated that the hot node in level II/III as depicted by SPECT/CT may be a risk of SN metastasis, including deeper nodes.

[Sentinel node invasion: is it necessary to perform axillary lymph node dissection? Randomized trial SERC]

Contribution of axillary lymph node dissection (ALND) is questioned for positive sentinel node (SN), micro-metastasis and isolated tumor cells but also for macro-metastasis. The aim of this work is to precise why a prospective randomized trial is necessary and the design of this trial. Why? For positive SN, the scientific level evidence appears insufficient for validation of ALND omission as a new standard. Rational is presented with non-sentinel node involved rate and number of NSL involved at complementary ALND, axillary recurrence rate, disease free survival rate and adjuvant treatment decision impact. How? The proposed Sentinelle Envahi et Randomisation du Curage (SERC) trial will randomly assign to observation only or complementary ALND with positive SN. The aim is to demonstrate the non-inferiority of ALND omission versus ALND.

Robust and validated models to predict high risk of non-sentinel node metastases in breast cancer patients with micrometastases or isolated tumor cells in the sentinel node

BACKGROUND

Benefit from axillary lymph node dissection in sentinel node positive breast cancer patients is under debate. Based on data from 1820 Danish breast cancer patients operated in 2002-2008, we have developed two models to predict high risk of non-sentinel node metastases when micrometastases or isolated tumor cells are found in sentinel node. The aim of this study was to validate these models in an independent Danish dataset.

MATERIAL AND METHODS

We included 720 breast cancer patients with micrometastases and 180 with isolated tumor cells in sentinel node operated in 2009-2010 from the Danish Breast Cancer Cooperative Group database. Accuracy of the models was tested in this cohort by calculating area under the receiver operating characteristic curve (AUC) as well as sensitivity and specificity.

RESULTS

AUC for the model for patients with micrometastases was comparable to AUC in the original cohort: 0.63 and 0.64, respectively. The sensitivity and specificity for predicting risk of non-sentinel node metastases over 30% was 0.36 and 0.81, respectively, in the validation cohort. AUC for the model for patients with isolated tumor cells decreased from 0.73 in the original cohort to 0.60 in the validation cohort. When dividing patients with isolated tumor cells into high and low risk of non-sentinel node metastases according to number of risk factors present, 37% in the high-risk group had non-sentinel node metastases. Specificity and sensitivity was 0.48 and 0.88, respectively, in the validation cohort when using this cut-point.

CONCLUSION

In this independent dataset, the model for patients with micrometastases was robust with accuracy similar to the original cohort, while the model for patients with isolated tumor cells was less accurate. The models may be used to identify patients where axillary lymph node dissection should still be considered.

[Breast cancer and axillary area: state of the art and perspectives]

A therapeutic surgical de-escalation has been observed since many years with an actual prolongation for axillary lymph node area treatment. Axillary lymph node dissection (ALND) omission has been studied before and after validation of sentinel node (SN) biopsy procedure. A non-inferiority of ALND omission has been reported in case of non-involved SN. ALND omission has been studied in case of SN involvement without consensus in relation with scientific level of proof and with selective indications. The purpose of this work is to make a synthesis of the experiences on this subject then to envisage the current and future perspectives.

Outcomes of a population-based series of early breast cancer patients with micrometastases and isolated tumour cells in axillary lymph nodes

BACKGROUND

Axillary lymph node staging is traditionally important to provide prognostic information to guide further treatment. However, the relevance of isolated tumour cells (ITC) or micrometastases in axillary nodes and the need for adjuvant treatment remain uncertain.

PATIENTS AND METHODS

Data from 18 370 patients with pT1-2 breast cancer with pN0, pN0i+ or pN1mi were analysed. The primary end point was 5-year disease-free survival (locoregional recurrence, distant metastases or contralateral breast cancer).

RESULTS

Five-year disease-free survival was 89.9% [95% confidence interval 89.5% to 90.4%]; and did not differ significantly between groups. After adjusting for prognostic factors (including treatment), patients with ITC had a comparable risk (hazard ratio = 1.12) as patients with node-negative disease, while patients with micrometastases had a 38% higher risk of recurrence.

CONCLUSION(S)

Patients with ITC and node-negative breast cancer appear to have similar prognosis, and those with micrometastases have a 38% higher risk of tumour recurrence. However, considering that disease-free survival is already high, we are reluctant to advise chemotherapy in all patients with ITC or micrometastases. In future, genomic tumour characteristics might predict the propensity of dissemination from the primary cancer better than the status of the axillary lymph nodes.

Applicability of two different validated models to predict axillary non-sentinel lymph node status by sentinel node biopsy in a single Italian center

BACKGROUND

The necessity of complete axillary lymph node dissection (CALND) after sentinel lymph node biopsy (SLNB) for women with sentinel lymph node metastases is a matter of debate because non-sentinel lymph nodes after CALND contain no further metastases in about 50 % of cases. Our study aims to determine the applicability in our setting of two different validated nomograms to predict axillary lymph node status after SLNB.

METHODS

We collected data about all women who underwent SLNB in our Department of Surgery from 2007 to 2010, focusing on tumor, patient, and breast characteristics. Data was analyzed by R (version 2.15.2); p < 0.05 was considered significant.

RESULTS

Among 511 women who underwent SLNB, 126 received CALND due to sentinel lymph node metastasis, and 73.0 % of these had no further metastatic non-sentinel lymph node. The area under the receiver operating characteristic (ROC) curves for the Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram and the Tenon score were 78.5 % (95 % CI 70.1-86.8 %) and 77.0 % (95 % CI 67.9-86.0 %) (p = 0.678), respectively.

CONCLUSIONS

Both the MSKCC nomogram and the Tenon score were predictive for the axillary non-sentinel lymph node status by SLNB. The MSKCC nomogram was the more accurate of the two and the Tenon score was the easier one to apply.

Ultrasound-guided fine-needle aspiration of suspicious nodes in breast cancer patients; selecting patients with extensive nodal involvement

The aim of this study was to evaluate the value of Ultrasonography (US) guided fine-needle aspiration (FNA) of the axilla to identify breast cancer patients with extensive nodal involvement. A prospective database of breast cancer patients who underwent US-guided FNA of suspicious nodes, diagnosed between 2000 and 2007 was analyzed. Patients with a negative axillary US or C2 (benign) FNA result underwent SLNB. Patients with C5 (malignant) FNA result underwent axillary lymph node dissection (ALND). All SLNB positive patients underwent completion ALND. The number of positive nodes after ALND was documented and analyzed. A total of 1,448 patients were included. US sensitivity was 34.2 %, specificity was 96.2 % and the accuracy was 71.7 %. For US-guided FNA this was 89, 100 and 90.4 %, respectively. In 234/1,448 patients (16.2 %) US-guided FNA was performed. A total of 19/41 C2 patients (46.3 %) had a positive SLNB. A median of 1 (range 1-6) positive node was found. A median of 4 (range 1-30) positive nodes were found in 158 C5 patients. In 376/1,214 patients with a negative US, SLNB was positive. A median of 2 (range 1-38) positive nodes were found. There was a significant difference in nodal involvement between C5 and SLNB positive patients (p = 0.043 and p < 0.0001, respectively). Ultrasound-guided FNA is a highly specific technique for detecting axillary metastases in breast cancer patients. Patients with US-guided FNA-diagnosed axillary metastases have significantly more involved nodes compared to SLNB positive patients.

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.

Implementation of step sectioning in the examination of sentinel lymph nodes to improve the detection of micrometastases in breast cancer patients

The object of this study was to examine whether a new protocol for examination of sentinel lymph nodes (SLNs) would lead to the detection of more metastases. Sections of 1 mm would identify most SLN macrometastases, and step sections at intervals of 200-250 μm would identify most micrometastases. A total of 111 breast cancer patients who underwent the SLN procedure at St. Olavs University Hospital in Trondheim, Norway in 2008 were included in the study group. Their SLNs were processed according to a new standardized protocol with sections of 2-3 mm being step sectioned at intervals of 200-250 μm. A total of 109 breast cancer patients undergoing the SLN procedure in 2007 were used as a reference group. Metastases were found in 29% of the cases, compared with 26% in the reference group. Step sectioning of SLNs revealed metastases in five cases initially found to be negative. The metastases of the study group were smaller, with a median value of 1.25 mm compared with 4.25 mm in the reference group. Step sectioning led to the detection of metastases in SLNs initially found to be negative. The median size of the metastases was considerably smaller in the study group than in the reference group.