The Prognostic Significance of Micrometastases in Breast Cancer: A SEER Population-Based Analysis

A novel nomogram and survival analysis for different lymph node status in breast cancer based on the SEER database

INTRODUCTION

The axillary lymph node status (ALNS) and internal mammary lymph nodes (IMLN) expression associated with breast cancer are closely linked to prognosis. This study aimed to establish a nomogram to predict survival at 3, 5, and 10 years in patients with various lymph node statuses.

METHODS

We obtained data from patients with breast cancer between 2004 and 2015 from the Surveillance, Epidemiology, and End Results (SEER database). Chi-square analysis was performed to test for differences in the pathological characteristics of the groups, and Kaplan-Meier analysis and the log-rank test were used to plot and compare the correlation between overall survival (OS) and breast cancer specific survival (BCSS). The log-rank test was used for the univariate analysis, and statistically significant characteristics were included in the multivariate and Cox regression analyses. Finally, Independent factor identification was included in constructing the nomogram using R studio 4.2.0; area under curve (AUC) values were calculated, and receiver operating characteristic (ROC) curve, calibration, and decision curve analysis (DCA) curves were plotted for evaluation.

RESULTS

A total of 279,078 patients were enrolled and analysed, demonstrating that the isolated tumour cells (ITC) group had clinicopathological characteristics similar to those of micrometastases (Mic). Multivariate analysis was performed to identify each subgroup's independent risk factors and construct a nomogram. The AUC values were 74.7 (95% CI 73.6-75.8), 72.8 (95% CI 71.9-73.8), and 71.2 (95% CI 70.2-72.2) for 3-, 5-, and 10-year OS, respectively, and 82.2 (95% CI 80.9-83.6), 80.1 (95% CI 79.0-81.2), and 75.5 (95% CI 74.3-76.8) for BCSS in overall breast cancer cases, respectively. AUC values for 3-, 5-, and 10-year OS in the ITC group were 64.8 (95% CI 56.5-73.2), 67.7 (95% CI 62.0-73.4), and 65.4 (95% CI 60.0-70.7), respectively. For those in the Mic group, AUC values for 3-, 5-, and 10-year OS were 72.9 (95% CI 70.7-75.1), 72.4 (95% CI 70.6-74.1), and 71.3 (95% CI 69.6-73.1), respectively, and AUC values for BCSS were 77.8 (95% CI 74.9-80.7), 75.7 (95% CI 73.5-77.9), and 70.3 (95% CI 68.0-72.6), respectively. In the IMLN group, AUC values for 3-, 5-, and 10-year OS were 75.2 (95% CI 71.7-78.7), 73.4 (95% CI 70.0-76.8), and 74.0 (95% CI 69.6-78.5), respectively, and AUC values for BCSS were 76.6 (95% CI 73.0-80.3), 74.1 (95% CI 70.5-77.7), and 74.7 (95% CI 69.8-79.5), respectively. The ROC, calibration, and DCA curves verified that the nomogram had better predictability and benefits.

CONCLUSION

This study is the first to investigate the predictive value of different axillary lymph node statuses and internal mammary lymph node metastases in breast cancer, providing clinicians with additional aid in treatment decisions.

Negative Survival Impact of Occult Lymph Node Involvement in Small HER2-Positive Early Breast Cancer Treated by Up-Front Surgery

(1) Background: The independent negative prognostic value of isolated tumor cells or micro-metastases in axillary lymph nodes has been established in triple-negative breast cancers (BC). However, the prognostic significance of pN0(i+) or pN1mi in HER2-positive BCs treated by primary surgery remains unexplored. Therefore, our objective was to investigate the impact of pN0(i+) or pN1mi in HER2-positive BC patients undergoing up-front surgery on their outcomes. (2) Methods: We retrospectively analyzed 23,650 patients treated in 13 French cancer centers from 1991 to 2013. pN status was categorized as pN0, pN0(i+), pN1mi, and pNmacro. The effect of pN0(i+) or pN1mi on outcomes was investigated both in the entire cohort of patients and in pT1a-b tumors. (3) Results: Of 1771 HER2-positive BC patients included, pN status distributed as follows: 1047 pN0 (59.1%), 60 pN0(i+) (3.4%), 118 pN1mi (6.7%), and 546 pN1 macro-metastases (30.8%). pN status was significantly associated with sentinel lymph node biopsy, axillary lymph node dissection, age, ER status, tumor grade, and size, lymphovascular invasion, adjuvant systemic therapy (ACt), and radiation therapy. With 61 months median follow-up (mean 63.2; CI 95% 61.5-64.9), only pN1 with macro-metastases was independently associated with a negative impact on overall, disease-free, recurrence-free, and metastasis-free survivals in multivariate analysis. In the pT1a-b subgroup including 474 patients, RFS was significantly decreased in multivariate analysis for pT1b BC without ACt (HR 2.365, 1.04-5.36, p = 0.039) and for pN0(i+)/pN1mi patients (HR 2.518, 1.03-6.14, p = 0.042). (4) Conclusions: Survival outcomes were not adversely affected by pN0(i+) and pN1mi in patients with HER2-positive BC. However, in the case of pT1a-b HER2-positive BC, a negative impact on RFS was observed specifically for patients with pN0(i+) and pN1mi diseases, particularly among those with pT1b tumors without ACt. Our findings highlight the importance of considering the pN0(i+) and pN1mi status in the decision-making process when discussing trastuzumab-based ACt for these patients.

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.

Characteristics of metastasis and survival between male and female breast cancer with different molecular subtypes: A population-based observational study

Objective

Male breast cancer (BC) is a rare disease, having different clinicopathological features and survival outcomes from female patients. The aim of this research was to, combine with molecular subtypes, analyze the metastatic patterns, and prognosis between male and female patients, and to determine whether the gender was the independent prognostic factor for BC.

Methods

Data used in this study were acquired from the SEER database from 2010 to 2016. The clinicopathology features and metastatic patterns were compared by the Chi‐square test and Fisher's exact test. Kaplan–Meier method was performed to compare overall survival (OS) and factors correlated with OS were determined by Cox regression models. Competing risk models were used to ascertain factors related to breast cancer‐specific death (BCSD).

Results

Compared with female BC, the incidence of regional LN (HR 1.849, 95% CI 1.674–2.043, p < 0.001) and distant metastasis (HR 1.421, 95%CI: 1.157–1.744, p < 0.001) was higher in male BC. For regional LN metastasis, hormone receptor (HoR)−/HER2+ subtype occupied the majority in both male (55.56%) and female (36.86%) groups. For distant metastasis, HoR−/HER2− subtype (21.26%), and HoR−/HER2+ (7.67%) were in major in male and female group separately. Male patients shared similar combinations of metastases with female groups as for single‐site, bi‐site, and tri‐site metastasis. Gender was an independent prognostic factor for OS (p < 0.001) but not for BCSD(p = 0.620). In subgroup of patients with HoR+/HER2−(OS: p = 0.003; BCSD: p = 0.606), HoR+/HER2+(OS: p = 0.003; BCSD: p = 0.277), regional LN positive(OS: p = 0.005; BCSD: p = 0.379), or bone metastasis (OS: p = 0.030; BCSD: p = 0.862), the male cohort had poorer OS but similar BCSD with female cohort.

Conclusions

Compared with female patients, male BC had different metastasis patterns and prognostic outcomes, and the affection of breast subtypes on metastasis and survivorship was also different. More attention needs to be paid for specific molecular subtype and more personalized therapeutic strategies should be customized while treating male patients.

Lack of prognostic impact of sentinel node micro-metastases in endocrine receptor-positive early breast cancer: results from a large multicenter cohort☆

Background

Prognostic impact of lymph node micro-metastases (pN1mi) has been discordantly reported in the literature. The need to clarify this point for decision-making regarding adjuvant therapy, particularly for patients with endocrine receptor (ER)-positive status and HER2-negative tumors, is further reinforced by the generalization of gene expression signatures using pN status in their recommendation algorithm.

Patients and methods

We retrospectively analyzed 13 773 patients treated for ER-positive breast cancer in 13 French cancer centers from 1999 to 2014. Five categories of axillary lymph node (LN) status were defined: negative LN (pN0i−), isolated tumor cells [pN0(i+)], pN1mi, and pN1 divided into single (pN1 = 1) and multiple (pN1 > 1) macro-metastases (>2 mm). The effect of LN micro-metastases on outcomes was investigated both in the entire cohort of patients and in clinically relevant subgroups according to tumor subtypes. Propensity-score-based matching was used to balance differences in known prognostic variables associated with pN status.

Results

As determined by sentinel LN biopsy, 9427 patients were pN0 (68.4%), 546 pN0(i+) (4.0%), 1446 pN1mi (10.5%) and 2354 pN1 with macro-metastases (17.1%). With a median follow-up of 61.25 months, pN1 status, but not pN1mi, significantly impacted overall survival (OS), disease-free survival (DFS), metastasis-free survival (MFS), and breast-cancer-specific survival. In the subgroup of patients with known tumor subtype, pN1 = 1, as pN1 > 1, but not pN1mi, had a significant prognostic impact on OS. DFS and MFS were only impacted by pN1 > 1. Similar results were observed in the subgroup of patients with luminal A-like tumors (n = 7101). In the matched population analysis, pN1macro, but not pN1mi, had a statistically significant negative impact on MFS and OS.

Conclusion

LN micro-metastases have no detectable prognostic impact and should not be considered as a determining factor in indicating adjuvant chemotherapy. The evaluation of the risk of recurrence using second-generation signatures should be calculated considering micro-metastases as pN0.

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LN micro-metastases have no detectable prognostic impact.

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pN1 status, but not pN1mi, significantly impacted overall survival, disease-free survival, metastasis-free survival.

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In the subgroup of patients with known tumor subtype, pN1=1, as pN1>1, but not pN1mi, had a significant prognostic impact on OS.

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LN micro-metastases should not be considered as a determining factor in indicating adjuvant chemotherapy.

Clinicopathological Follow-up of Breast DCIS Diagnosed on Biopsies: A Single Institutional Study of 575 Patients

Stratifying ductal carcinoma in situ (DCIS) patients into different upgrading risk groups is important in exploiting more precise therapeutic options. Evaluation of estrogen receptor/progesterone receptor/human epidermal growth factor receptor 2 (ER/PR/HER2) status and axillary lymph node metastatic status for DCIS and their upgraded invasive counterparts can also provide diagnostic and therapeutic implications. We retrospectively studied 575 patients with first-time diagnosis of DCIS on biopsies, and followed up their final diagnosis, ER/PR/HER2 status, and axillary lymph node involvement on excisions. As a result, biopsy-diagnosed DCIS had an overall 19.1% risk to be upgraded on subsequent excisions, with 4.7% being upgraded to microinvasive carcinoma (pT1mi) and 14.4% to overt invasive carcinoma (⩾pT1a). Factors significantly associated with higher upgrading risk on multivariate analysis include biopsy guidance by ultrasound (P <.001), DCIS with suspicious microinvasion (P < .001), and DCIS diagnosed in left breast (P = .026). DCIS diagnosed in younger patients (⩽40 years old) or DCIS with high nuclear grade showed higher upgrading risk only on univariate analysis. About 80% ER + /PR + and ER-/PR- DCIS remained the same ER/PR status after being upgraded, and ER + /PR -  DCIS had the highest risk (63.6%) of having HER2 amplification in upgraded invasive carcinoma. For upgraded DCIS, microinvasive carcinoma was more likely to have HER2 amplification (50%) than overt invasive carcinoma (29.5%). Besides, pure DCIS had a low risk of axillary lymph node macrometastasis (0.74%), while the risk increased in DCIS with microinvasion (4.4%) and was highest in overt invasive carcinoma (14.7%). The findings of this study are clinically relevant with respect to criteria that might be used in selecting patients for de-escalation trials.

Clinical effect of the pathological axillary assessment method in breast cancer without clinical nodal metastasis

BACKGROUND

This study aimed to assess the clinical effect of the pathological axillary assessment method in breast cancer without clinical lymph node metastasis.

METHODS

Data of patients with clinically node-negative breast cancer were retrospectively reviewed. The study period was divided into early (January 2000-July 2007) and late (August 2007-December 2014) periods based on the pathological assessment method used (single-sectional and detailed multi-sectional lymph node processing). In the late period, lymph nodes were evaluated at six levels including immunohistochemistry on each 1.5-2 mm interval section. The axillary diagnostic accuracy and role of chemotherapy were assessed.

RESULTS

In 1698 patients, 27 isolated tumor cells (ITCs), 39 micrometastases, and 205 macrometastases were noted. The sensitivity for pathological N0 diagnosis was dependent on clinical T stage, Tis (97.8%), T1 (83.0%), T2 (74.2%), T3 (54.5%), and T4 (63.6%). ITCs and micrometastases were detected only in the late period, and 84.7% and 91.6% of cases in the early and late period, respectively, did not have macrometastases. The 5-year disease-free interval (DFI) rates were 95.2% in node-negative cases, 98.4% in ITCs/micrometastases, and 91.4% in macrometastases (P < 0.001). In multivariate analysis, the predictor for DFI was estrogen receptor negativity (P = 0.013). Chemotherapy did not improve DFI in patients with node-positive breast cancer.

CONCLUSIONS

The detailed multi-sectional pathological assessment of axillary lymph nodes detected ITCs and micrometastases. Implementation of chemotherapy should not be based on the minimal nodal metastasis and this type of serially nodal sectioned processing had little clinical significance.

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.

Prognostic value of occult lymph node metastases in patients with completely resected esophageal squamous cell carcinoma

To investigate the prognostic value of occult lymph node metastases (OLNMs) in patients with pathologically lymph node negative (pN0) esophageal squamous cell carcinoma (ESCC). OLNMs were detected in 516 pN0 ESCC patients by immunohistochemical staining. The correlation between the clinicopathological features and OLNM, and the prognostic value of OLNM was explored. Eighty-eight patients (17.1%) had OLNMs, including 37 patients with isolated tumor cells (ITCs), 49 patients with micrometastases, and 2 patients with macrometastases (> 2 mm). The OLNM-positive group had poorer differentiation and a more advanced pT category. The 5-year overall survival and disease-free survival for patients with OLNMs were significantly worse than those of IHC-negative patients (P < 0.001), but similar to those of the pN1 patients (P > 0.05). The multivariate analysis showed that OLNM was an independent prognostic factor. In subgroup analyses, the IHC-negative patients had significant survival advantages compared with the ITC group and the micrometastasis group, whereas the survival for the ITC group was similar to that of the micrometastasis group. IHC staining in pN0 ESCC patients might help to identify patients at high risk of death after resection, and ITCs in the lymph nodes appear to have a prognostic value equal to that of micrometastases.

Role of Sentinel Lymph Node Biopsy in Microinvasive Breast Cancer

BACKGROUND

Microinvasive ductal carcinoma (DCISM), defined as DCIS with a focus of invasive carcinoma ≤ 1 mm, can be managed similarly to pure DCIS; however, management of the axilla in DCISM has been a subject of debate. Reports in the literature differ on the utility and necessity of sentinel lymph node biopsy (SLNB) for DCISM. The aim of the present study was to identify risk factors for nodal disease in patients with DCISM, which can help develop a selective approach to SLNB in this patient population.

METHODS

The National Cancer Database was used to select patients with DCISM (pT1mi), diagnosed from 2012 to 2015, who underwent SLNB. Multivariable regression analysis was performed to determine associations between sentinel lymph node metastasis and relevant clinical variables.

RESULTS

Our cohort comprised of 2609 patients with pT1mi who underwent SLNB. Of these, 76 (2.9%) were found to have sentinel lymph node metastases on final pathology. Low/intermediate grade tumors were associated with decreased SLN metastasis (OR 0.50, CI 0.28-0.92). Age and receptor status of the tumor did not have a clear association in predicting SLN metastases.

CONCLUSIONS

The rate of sentinel node metastases in DCISM is low at only 2.9% in this national study. Tumor grade was identified as influencing the risk of SLN metastases. This information can factor into shared decision-making for SLNB in patients with DCISM.

The effect of post mastectomy radiation therapy on survival in breast cancer patients with N1mic disease

Background

The role of post mastectomy radiation therapy (PMRT) in patients with N1mic breast cancer has not been well defined. A retrospective analysis was performed using the SEER database to evaluate the impact of PMRT on survival in patients with N1mic breast cancer.

Materials and methods

Women with T1-T2, N1mic, M0 breast cancer who had undergone mastectomy were analyzed. Descriptive statistics were calculated for all variables. Univariate analysis to assess for differences in survival with respect to covariates was performed using the log rank test while multivariate analysis was performed with Cox proportional hazards regression. Sub-cohort analysis with propensity score matching was used to assess differences in survival among patients undergoing PMRT vs no PMRT. Comparisons were considered statistically significant at P < 0.05.

Results

Among 5878 patients, 1202 (20%) underwent PMRT. On univariate analysis, PMRT was a significant predictor of CSS, but not OS. There was no difference in either OS or CSS between the PMRT vs no PMRT groups on multivariate Cox regression analysis and after propensity score matching.

Conclusions

Among patients with T1-T2, N1mic, M0 breast IDC from the SEER database, there was no difference in either OS or CSS among patients who underwent PMRT vs no PMRT. These results suggest that PMRT does not impact survival among breast cancer patients with N1mic disease. However, additional prospective studies with longer follow up are necessary for further evaluation.

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In women with N1mic breast cancer, there was no difference in overall survival with or without adjuvant radiation.

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CSS was worse among women undergoing adjuvant radiation on univariate analysis, but not on multivariate analysis.

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After propensity score matching, no significant difference was observed in survival between women undergoing PMRT vs no PMRT.

Postmastectomy radiation therapy in early breast cancer: Utility or futility?

Postmastectomy radiation therapy (PMRT) has been shown to reduce the risk of locoregional recurrence (LRR), in patients with locally advanced breast cancer who are considered of high-risk because of large tumors (>5 cm) or presence of axillary lymph-node involvement, as well as to reduce breast cancer mortality. However, controversy still remains with respect to indication of PMRT in case of early-stages invasive tumors. This review aims to analyze the impact that PMRT has on final results in women with breast tumors in different scenarios that would otherwise be considered as early breast cancer, such as extensive DCIS, tumors without axillary lymph-node involvement or with minimal microscopic nodal-involvement. The existence of risk factors including young age, premenopausal status, and presence of lymphovascular invasion (LVI), high grade or tumor size >2 cm has been associated with an increased risk of LRR in these patients at early-stages and advises to consider PMRT in selected cases.

Cytomorphological Characterization of Individual Metastatic Tumor Cells from Gastrointestinal Cancer Patient Lymph Nodes with Imaging Flow Cytometry

The presence or absence of tumor cells within patient lymph nodes is an important prognostic indicator in a number of cancer types and an essential element of the staging process. However, patients with the same pathological stage will not necessarily have the same outcome. Therefore, additional factors may aid in identifying patients at a greater risk of developing metastasis. In this proof of principle study, initially, spiked tumor cells in rat lymph nodes were used to mimic a node with a small cancer deposit. Next, human lymph nodes were obtained from cancer patients for morphological characterization. Nodes were dissociated with a manual tissue homogenizer and stained with fluorescent antibodies against CD45 and Pan-Cytokeratin and then imaging flow cytometry (AMNIS ImageStreamX Mark II) was performed. We show here that imaging flow cytometry can be used for the detection and characterization of small numbers of cancer cells in lymph nodes and we also demonstrate the phenotypical and morphological characterization of cancer cells in gastrointestinal cancer patient lymph nodes. When used in addition to conventional histological techniques, this high throughput detection of tumor cells in lymph nodes may offer additional information assisting in the staging process with therapeutic and prognostic applications.

Prediction of Lymph Node Metastasis in Breast Cancer by Gene Expression and Clinicopathological Models: Development and Validation within a Population-Based Cohort

PURPOSE

More than 70% of patients with breast cancer present with node-negative disease, yet all undergo surgical axillary staging. We aimed to define predictors of nodal metastasis using clinicopathological characteristics (CLINICAL), gene expression data (GEX), and mixed features (MIXED) and to identify patients at low risk of metastasis who might be spared sentinel lymph node biopsy (SLNB).Experimental Design: Breast tumors (n = 3,023) from the population-based Sweden Cancerome Analysis Network-Breast initiative were profiled by RNA sequencing and linked to clinicopathologic characteristics. Seven machine-learning models present the discriminative ability of N0/N+ in development (n = 2,278) and independent validation cohorts (n = 745) stratified as ER⁺HER2^-, HER2⁺, and TNBC. Possible SLNB reduction rates are proposed by applying CLINICAL and MIXED predictors.

RESULTS

In the validation cohort, the MIXED predictor showed the highest area under ROC curves to assess nodal metastasis; AUC = 0.72. For the subgroups, the AUCs for MIXED, CLINICAL, and GEX predictors ranged from 0.66 to 0.72, 0.65 to 0.73, and 0.58 to 0.67, respectively. Enriched proliferation metagene and luminal B features were noticed in node-positive ER⁺HER2^- and HER2⁺ tumors, while upregulated basal-like features were observed in node-negative TNBC tumors. The SLNB reduction rates in patients with ER⁺HER2^- tumors were 6% to 7% higher for the MIXED predictor compared with the CLINICAL predictor accepting false negative rates of 5% to 10%.

CONCLUSIONS

Although CLINICAL and MIXED predictors of nodal metastasis had comparable accuracy, the MIXED predictor identified more node-negative patients. This translational approach holds promise for development of classifiers to reduce the rates of SLNB for patients at low risk of nodal involvement.

21-Gene Recurrence Score Assay Could Not Predict Benefit of Post-mastectomy Radiotherapy in T1-2 N1mic ER-Positive HER2-Negative Breast Cancer

Introduction: It is still controversial whether post-mastectomy radiotherapy (PMRT) is necessary for women with T1-2 N1mic ER-positive HER2-negative breast cancer. The 21-gene recurrence score (RS) assay has been validated in T1-2 N1 breast cancer to be prognostic of locoregional recurrence (LRR) and overall survival (OS). This study aims to evaluate the predict value of 21-gene recurrence score assay for the benefit of PMRT in T1-2 N1mic ER-positive HER2-negative breast cancer.

Methods: A population-based cohort study was performed on women with T1-2 N1mic ER-positive HER2-negative breast cancer who underwent mastectomy and were evaluated using the 21-gene RS in the Surveillance, Epidemiology, and End Results (SEER) registry between 2004 and 2015. Clinical characteristics as well as OS and breast cancer-specific survival (BCSS) were compared between patients with and without PMRT in patients with a Low-, Intermediate-, and High-RS. Multivariate COX regression analysis was performed to investigate if the 21-gene RS assay could predict benefit of PMRT in this group of breast cancer patients.

Results: A total of 1571 patients met the criteria of our study and were enrolled, including 970 patients in the Low-Risk group (score <18), 508 in the Intermediate-Risk group (score 18–30), and 93 patients in the High-Risk group (score >30). In the High-Risk group, there were more patients with age ≥50 (87.0 vs. 64.3%, P = 0.040) and received chemotherapy with a borderline significance (91.3 vs. 72.9%, P = 0.066) in the PMRT subgroup than in the no PMRT subgroup. In all three groups, OS was comparable between the PMRT subgroup and the no PMRT subgroup. Furthermore, multivariate analysis did not show any OS benefit for PMRT based on the 21-gene recurrence score.

Conclusion: This study showed that the 21-gene RS assay was not able to predict the benefit of PMRT for OS in women with T1-2 N1mic ER-positive HER2-negative breast cancer. However, further prospective larger sample-size trials are warranted to determine if a benefit exists.

Why is pancreatic cancer so deadly? The pathologist's view

The remarkable aggressiveness of pancreatic cancer has never been fully explained. Although clearly multifactorial, we postulate that venous invasion, a finding seen in most pancreatic cancers but not in most cancers of other organs, may be a significant, underappreciated contributor to the aggressiveness of this disease. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Impact of Micrometastatic Axillary Nodes on Survival of Breast Cancer Patients with Tumors ≤2 cm

BACKGROUND

This study investigated the impact of pN1mi disease on the survival of T1 breast cancer patients and examined the clinical usefulness of the online PREDICT tool and updated staging system.

METHODS

The node stages of 2344 patients were divided into pN0, pN1mi, and pN1a. Clinicopathological parameters and survival outcomes were retrospectively analyzed. Data for 111 micrometastatic diseases were applied to the PREDICT version 2.0 and re-classified using the 8th edition of the cancer staging manual.

RESULTS

Univariable analyses demonstrated worse disease-free and overall survival rates for patients with node-positive cancer; however, the significance was not maintained in multivariable analyses. Chemotherapy improved outcomes in patients with node-positive and non-luminal A-like subtype cancers. The PREDICT tool demonstrated good performance when estimating the 5-year overall survival for pN1mi disease (area under the receiver operating characteristic curve, 0.834). According to the updated staging system, 74% of cases were down-staged to IA, and clearly splitting survival curves were identified.

CONCLUSION

pN1mi disease alone did not adversely affect survival outcomes. Biologic and treatment factors determined outcomes in cases of small-volume node micrometastasis. The PREDICT tool or new staging classification could help predict the survival of patients with micrometastatic sentinel nodes.

Contemporary Evaluation of Breast Lymph Nodes in Anatomic Pathology

OBJECTIVES

Management of the axilla in breast cancer patients has evolved considerably since the introduction of the sentinel lymph node (SLN) biopsy in the 1990s. Several new clinical and technological developments in the last decade warrant special consideration due to their impact on pathology practice.

METHODS

This review covers the SLN biopsy procedure, issues in the histopathologic and molecular diagnosis of the SLN, and most importantly, evidence from recent practice-changing clinical trials.

RESULTS

ACOSOG Z0011, IBCSG 23-01, and AMAROS trials have shown that early-stage breast cancer patients who have limited metastatic involvement of the SLNs do not benefit from completion axillary dissections.

CONCLUSIONS

It is not necessary for pathologists to search for all small metastases to predict non-SLN involvement, regional recurrence, or death due to disease. Processing should be designed with the goal of detecting macrometastases. Multiple levels, routine immunohistochemistry, and molecular testing are not recommended.

Prognostic significance of further axillary dissection in breast cancer patients with micrometastases & the number of micrometastases: a SEER population-based analysis

Aim:

To investigate the benefits of axillary dissection in patients with micrometastases.

Methods:

A review of data from the Surveillance, Epidemiology, and End Results database was performed from 2004 to 2013. Kaplan–Meier curves, Cox regression models, and propensity score matching were utilized to comprehensively evaluate the cohort.

Results:

Multivariate analysis after propensity score matching showed that patients with one to two micrometastases did not substantially benefit from axillary lymph node dissection in breast cancer-specific survival (p = 0.725). However, a subgroup analysis indicated that axillary dissection may benefit estrogen receptor-negative patients. Moreover, patients who carried three micrometastases had a significantly lower crude hazard ratio in breast cancer-specific survival.

Conclusion:

Axillary lymph node dissection may have advantages in high-risk micrometastatic patients. Patients with three micrometastases should be treated with caution.

The current study demonstrated that among patients undergoing breast-conserving surgery following radiation with T1–T2 invasive breast cancer and one to two nodal micrometastases, there was no difference in the breast cancer-specific survival for patients with and without axillary lymph node dissection. Although negative results of the Z0011 and International Breast Cancer Study Group 23–01 trials have been reported, high-risk micrometastatic patients (e.g., estrogen receptor negative, young age) may be candidates for radical axillary treatment according to the unclear radiation field and higher recurrence rate. The preliminary assessment of  three micrometastatic patients showed a lower breast cancer-specific survival than patients with one to two micrometastases. This study provides a novel perspective to the American Joint Committee on Cancer with respect to micrometastases.

Association of One-Step Nucleic Acid Amplification Detected Micrometastases with Tumour Biology and Adjuvant Chemotherapy

One-step nucleic acid amplification (OSNA) is an intraoperative technique with a high sensitivity and specificity for sentinel node assessment. The aim of this study was to assess the impact of OSNA on micrometastases detection rates and use of adjuvant chemotherapy. A retrospective review of patients with sentinel node micrometastases over a five-year period was carried out and a comparison of micrometastases detection using OSNA and H&E techniques was made. Out of 1285 patients who underwent sentinel node (SLN) biopsy, 76 patients had micrometastases. Using H&E staining, 36 patients were detected with SLN micrometastases (9/year) in contrast to 40 patients in the OSNA year (40/year) (p < 0.0001), demonstrating a fourfold increase with the use of OSNA. In the OSNA group, there was also a proportional increase in Grade III, triple-negative, ER-negative, and HER-2-positive tumours being diagnosed with micrometastases. Also on interactive PREDICT tool, the number of patients with a predicted 10-year survival benefit of more than 3% with adjuvant chemotherapy increased from 52 to 70 percent. OSNA has resulted in an increased detection rate of micrometastases especially in patients with aggressive tumour biology. This increased the number of patients who had a predicted survival benefit from adjuvant chemotherapy.

Medico-economic impact of MSKCC non-sentinel node prediction nomogram for ER-positive HER2-negative breast cancers

Background

Avoiding axillary lymph node dissection (ALND) for invasive breast cancers with isolated tumor cells or micrometastatic sentinel node biopsy (SNB) could decrease morbidity with minimal clinical significance.

Purpose

The aim of this study is to simulate the medico-economic impact of the routine use of the MSKCC non-sentinel node (NSN) prediction nomogram for ER+ HER2- breast cancer patients.

Methods

We studied 1036 ER+ HER2- breast cancer patients with a metastatic SNB. All had a complementary ALND. For each patient, we calculated the probability of the NSN positivity using the MSKCC nomogram. After validation of this nomogram in the population, we described how the patients’ characteristics spread as the threshold value changed. Then, we performed an economic simulation study to estimate the total cost of caring for patients treated according to the MSKCC predictive nomogram results.

Results

A 0.3 threshold discriminate the type of sentinel node (SN) metastases: 98.8% of patients with pN0(i+) and 91.6% of patients with pN1(mic) had a MSKCC score under 0.3 (false negative rate = 6.4%). If we use the 0.3 threshold for economic simulation, 43% of ALND could be avoided, reducing the costs of caring by 1 051 980 EUROS among the 1036 patients.

Conclusion

We demonstrated the cost-effectiveness of using the MSKCC NSN prediction nomogram by avoiding ALND for the pN0(i+) or pN1(mic) ER+ HER2- breast cancer patients with a MSKCC score of less than or equal to 0.3.

Sentinel Lymph Nodes for Breast Carcinoma: A Paradigm Shift

CONTEXT

-Sentinel lymph node biopsy has been established as the new standard of care for axillary staging in most patients with invasive breast carcinoma. Historically, all patients with a positive sentinel lymph node biopsy result underwent axillary lymph node dissection. Recent trials show that axillary lymph node dissection can be safely omitted in women with clinically node negative, T1 or T2 invasive breast cancer treated with breast-conserving surgery and whole-breast radiotherapy. This change in practice also has implications on the pathologic examination and reporting of sentinel lymph nodes.

OBJECTIVE

-To review recent clinical and pathologic studies of sentinel lymph nodes and explore how these findings influence the pathologic evaluation of sentinel lymph nodes.

DATA SOURCES

-Sources were published articles from peer-reviewed journals in PubMed (US National Library of Medicine) and published guidelines from the American Joint Committee on Cancer, the Union for International Cancer Control, the American Society of Clinical Oncology, and the National Comprehensive Cancer Network.

CONCLUSIONS

-The main goal of sentinel lymph node examination should be to detect all macrometastases (>2 mm). Grossly sectioning sentinel lymph nodes at 2-mm intervals and evaluation of one hematoxylin-eosin-stained section from each block is the preferred method of pathologic evaluation. Axillary lymph node dissection can be safely omitted in clinically node-negative patients with negative sentinel lymph nodes, as well as in a selected group of patients with limited sentinel lymph node involvement. The pathologic features of the primary carcinoma and its sentinel lymph node metastases contribute to estimate the extent of non-sentinel lymph node involvement. This information is important to decide on further axillary treatment.

The impact of nodal micrometastasis on mortality among women with early-stage breast cancer

PURPOSE

The clinical significance of nodal micrometastasis is debated. Our primary objective was to determine whether, among women with early-stage breast cancer, regional lymph node micrometastasis is an independent risk factor for mortality. The secondary objective was to identify subgroups of women who have the highest risk of death from early-stage breast cancer with micrometastases.

METHODS

206,625 women diagnosed with early-stage breast cancer (IA, IB, and IIA) from 2004 to 2012 were identified in the Surveillance, epidemiology, and end results database. Nodal status was classified as node-negative, isolated-tumor cells, micrometastases, and macrometastases. Women were classified into eight ethnic groups. Logistic regression was performed to estimate the odds ratio of being diagnosed with micrometastases. The Cox proportional hazard model was used to estimate the hazard ratio (HR) of breast cancer-specific death associated with micrometastases for each ethnic group.

RESULTS

The 8-year breast cancer-specific survival was 96.6 % for women with node-negative breast cancers and was 94.6 % for women with micrometastases (adjusted HR 1.49; 95 % CI 1.31-1.69; P < .001). Among women with micrometastases, the 8-year breast cancer-specific survival was 95.1 % for white women and was 90.6 % for black women (HR 1.80; 95 % CI 1.29-2.52; P = .0006).

CONCLUSION(S)

Nodal micrometastasis is an independent risk factor for breast cancer mortality among women with early-stage breast cancer. Black women are more likely to die from breast cancer with micrometastases than white women.

Article Commentary: Surgical Management of the Axilla in Breast Cancer

This article offers a review of the literature on current surgical management of the axilla in breast cancer. This includes the decision-making process involved in clinically node-negative patients versus clinically node-positive patients, with discussion of the indications for sentinel lymph node biopsy versus axillary dissection. It also examines the surgical axillary management of patients who receive neoadjuvant chemotherapy. This article will help update practicing surgeons on the evolving research and guidelines for the management of breast cancer axillary disease.

Successful Completion of the Pilot Phase of a Randomized Controlled Trial Comparing Sentinel Lymph Node Biopsy to No Further Axillary Staging in Patients with Clinical T1-T2 N0 Breast Cancer and Normal Axillary Ultrasound

BACKGROUND

Axillary surgery is not considered therapeutic in patients with clinical T1-T2 N0 breast cancer. The importance of axillary staging is eroding in an era in which tumor biology, as defined by biomarker and gene expression profile, is increasingly important in medical decision making. We hypothesized that axillary ultrasound (AUS) is a noninvasive alternative to sentinel lymph node biopsy (SLNB), and AUS could replace SLNB without compromising patient care.

STUDY DESIGN

Patients with clinical T1-T2 N0 breast cancer and normal AUS were eligible for enrollment. Subjects were randomized to no further axillary staging (arm 1) vs SLNB (arm 2). Descriptive statistics were used to describe the results of the pilot phase of the randomized controlled trial.

RESULTS

Sixty-eight subjects were enrolled in the pilot phase of the trial (34 subjects in arm 1, no further staging; 32 subjects in arm 2, SLNB; and 2 subjects voluntarily withdrew from the trial). The median age was 61 years (range 40 to 80 years) in arm 1 and 59 years (range 31 to 81 years) in arm 2, and there were no significant clinical or pathologic differences between the arms. Median follow-up was 17 months (range 1 to 32 months). The negative predictive value (NPV) of AUS for identification of clinically significant axillary disease (>2.0 mm) was 96.9%. No axillary recurrences have been observed in either arm.

CONCLUSIONS

Successful completion of the pilot phase of the randomized controlled trial confirms the feasibility of the study design, and provides prospective evidence supporting the ability of AUS to exclude clinically significant disease in the axilla. The results provide strong support for a phase 2 randomized controlled trial.

Sentinel Lymph Node in Breast Cancer: Review Article from a Pathologist's Point of View

Breast cancer staging, in particular N-stage changed most significantly due to the advanced technique of sentinel lymph node biopsy two decades ago. Pathologists have more thoroughly examined and scrutinized sentinel lymph node and found increased number of small volume metastases. While pathologists use the strict criteria from the Tumor Lymph Node Metastasis (TNM) Classification, studies have shown poor reproducibility in the application of American Joint Committee on Cancer and International Union Against Cancer/TNM guidelines for sentinel lymph node classification in breast cancer. In this review article, a brief history of TNM with a focus on N-stage is described, followed by innate problems with the guidelines, and why pathologists may have difficulties in assessing lymph node metastases uniformly. Finally, clinical significance of isolated tumor cells, micrometastasis, and macrometastasis is described by reviewing historical retrospective data and significant prospective clinical trials.

Intraoperative Frozen Section Evaluation of Sentinel Lymph Nodes in Breast Carcinoma: Single-Institution Indian Experience

Sentinel lymph node biopsy is an established way of predicting axillary nodal metastasis in early breast cancer. Intraoperative frozen sections (FS) of sentinel lymph nodes (SLNs) can be used to detect metastatic disease, allowing immediate axillary lymph node dissection. The purpose of this study was to evaluate the accuracy of intraoperative frozen sections in evaluation of sentinel lymph nodes in cases of breast cancer. Between March 2006 and August 2010, a total of 164 patients with clinically node-negative operable breast cancer were subjected to sentinel lymph node biopsy of axillary lymph nodes using preoperative peritumoral injection of radioactive colloid and methylene blue. Intraoperative identification of sentinel nodes was done using a handheld gamma probe and identification of blue-stained nodes. The nodes were sent for frozen section examination. The results of frozen section were compared with the final histopathology. Out of the 164 cases, metastases were detected in SLN by frozen section in 38 cases. There were three false-negative cases (all showing micrometastasis on final histopathology). FS had sensitivity of 92.6 %, specificity of 100 %, and overall accuracy of 98.1 %. The positive predictive value was 100 %, and the negative predictive value was 97.6 %. FS for diagnosis of metastasis of SLNs is reliable. Patients with negative SLNs by the FS diagnosis can avoid reoperation for axillary lymph node dissection. However, FS may fail to detect micrometastases, especially in cases with small tumors.

Occult metastases in node-negative breast cancer: A Surveillance, Epidemiology, and End Results-based analysis

INTRODUCTION

The role of immunohistochemistry (IHC) for detecting occult lymph node disease in patients initially found to be node-negative by routine pathology is controversial. In this study, we evaluated trends associated with overall survival in node-negative breast cancer patients staged by IHC.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for all patients with invasive breast adenocarcinoma and negative lymph nodes on routine pathology between 2004 and 2011 who underwent IHC to evaluate for occult nodal disease. Overall survival stratified by N-stage was compared with Kaplan-Meier analysis. Multivariate analysis was performed using a Cox proportional hazards model.

RESULTS

Overall, 93,070 patients were identified, including 4,657 patients with isolated tumor cells (<0.2 mm diameter or <200 cells) and 6,720 patients with micrometastases (0.2-2 mm diameter). Kaplan-Meier curves demonstrated a difference in overall survival across all groups (P < .0001). On multivariate analysis, micrometastases remained an independent predictor for survival compared with IHC-negative patients (hazard ratio 1.40, 95% confidence interval 1.28-1.53), whereas isolated tumor cells were not a significant predictor (hazard ratio 1.05, 95% confidence interval 0.92-1.20).

CONCLUSION

Patients with occult micrometastases in axillary lymph nodes found via IHC demonstrated a significant overall survival difference, but isolated tumor cells have no prognostic significance.

Breast cancer metastasis burden in sentinel nodes analysed using one-step nucleic acid amplification predicts axillary nodal status

BACKGROUND

In breast cancer patients undergoing sentinel lymph node biopsy (SLNB) analysis using one-step nucleic acid amplification (OSNA), clarity is required as to the risk factors for non-sentinel lymph node (NSLN) involvement upon axillary lymph node dissection (ALND). This study aims to identify these factors, including categorising by extent of sentinel node positivity: solitary positive node (solitary), multiple nodes with some positive (multiple incomplete positive), or multiple nodes all of which are positive (multiple all positive).

METHODS

We conducted a cohort study using prospectively collected data on 856 SLNBs analysed using OSNA, from patients with cT1-3 clinically node-negative invasive breast cancer. ALND was performed for 289 positive SLNBs.

RESULTS

NSLN metastases were identified in 73 (25.3%) ALNDs. Significant factors for NSLN involvement on multivariate analysis were: SLNB macrometastases (cytokeratin-19 mRNA count >5000 copies/μl) (adj.OR = 3.01; 95% CI, 1.61-5.66; p = 0.0006), multiple all positive vs. multiple incomplete positive SLNB (adj.OR = 2.92; 95% CI, 1.38-6.19; p = 0.0050), and undergoing mastectomy (adj.OR = 1.89; 95% CI, 1.00-3.55; p = 0.0486). Amongst multiple incomplete positive SLNBs, an 8.8% NSLN risk was identified when only micrometastases were present.

CONCLUSION

Extent of sentinel lymph node positivity measured using OSNA predicts NSLN metastasis risk, aiding decisions surrounding axillary treatment.

[Is there a rationale for regional node irradiation in pN1mi and pN0(i+) breast tumours?]

The advent of sentinel lymph node technique has led to a shift in lymph node staging, due to the emergence of new entities, namely micrometastases and isolated tumour cells. In addition, the therapeutic role of axillary lymph node dissection is more and more questioned and radiotherapy has been shown to be equivalent to complementary axillary lymph node dissection in patients without clinical node involvement. This article looks at the literature in favour of performing axillary irradiation in patients with pN1mi stage breast cancer who have undergone a mastectomy without a complementary axillary lymph node dissection, and in favour of abstention of any further treatment of the axilla in patients with pN0(i+) or pN1mi tumours who have undergone breast conserving surgery and a sentinel lymph node procedure followed by systemic treatment. The impact of regional lymph nodes irradiation in case of axillary involvement 2mm or less is also discussed.

[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.

The Will Rogers phenomenon in the staging of breast cancer - does it matter?

INTRODUCTION

Changes in the American Joint Commission on Cancer staging for breast cancer occurred when the 5th Edition was updated to the 6th Edition.

OBJECTIVE

To investigate how these changes affected stage and survival.

METHODS

3127 cases of breast cancer were restaged.

RESULTS

Late stages increased from 27.7% to 38.1%. The five-year survival improved in Stage 2 (82.9-86.1%) and Stage 3 (50.6-59%).

DISCUSSION

Stage shift leads to an erroneous impression that women are presenting with later stages and stage-specific survival is improving.

CONCLUSION

Standardizing cancer staging is important when reporting stage and survival in different time periods.

Evolution of sentinel lymph node biopsy in breast cancer, in and out of vogue?

Sentinel lymph node biopsy (SLNB) was introduced 2 decades ago and thereafter validated for routine surgical management of breast cancer, including cases treated with neoadjuvant chemotherapy. As the number of lymph nodes for staging has decreased, pathologists have scrutinized SLN with a combination of standard hematoxylin and eosin, levels, immunohistochemistry (IHC), and molecular methods. An epidemic of small-volume metastases thereby arose, leading to modifications in the American Joint Committee on Cancer staging to accommodate findings such as isolated tumor cells (ITC) and micrometastases. With the goal of determining the significance of these findings, retrospective followed by prospective trials were performed, showing mixed results. The ACOSOG Z10 and NSABP B-32 trials both independently showed that ITC and micrometastases were not significant and thus discouraged the use of levels and IHC for detecting them. However, the Surveillance Epidemiology and End Results database showed that patients with micrometastases had an overall decreased survival. In addition, the MIRROR (Micrometastases and ITC: Relevant and Robust or Rubbish?) trial, showed that patients with ITC and micrometastases treated with adjuvant therapy had lower hazard ratios compared with untreated patients. Subsequently, the ACOSOG Z0011 trial randomized patients with up to 2 positive SLN to axillary lymph node dissection (ALND) or not, all treated with radiation and chemotherapy, showing no difference in survival or recurrence rates between the 2 groups and causing a shift from ALND. As the rate of ALND has declined, the necessity of performing levels, IHC, frozen section, and molecular studies on SLN needs to be revisited.

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.

Impact of sentinel node tumor burden on outcome of invasive breast cancer patients

BACKGROUND

The tumor status of the axillary lymph nodes is one of the most important prognostic factors in women with early breast cancer (BC). Sentinel lymph node (SLN) biopsy has become the standard staging procedure for patients with invasive BC, largely replacing axillary lymph nodes dissection (ALND). The exact impact on prognosis of SLN tumor burden is still object of controversy. The aim of this study was to correlate the tumor burden in the SLN with the outcome in a large cohort of women.

PATIENTS AND METHODS

1040 consecutive patients with clinical stage I-III invasive BC were prospectively collected on our Institutional BC database from January 2001 to January 2007. Patients were stratified into the following four groups based on the tumor burden of the SLN: macrometastases, tumor deposit ≥2 mm; micrometastases, tumor deposit ≥0.2 mm and <2 mm; isolated tumor cells (ITC), isolated tumor cells or tumor deposit <0.2 mm; negative, in case of patients with no evidence of tumor.

RESULTS

At a median follow-up of 8.5 years, the tumor burden of SLN metastases resulted significant predictor of DFS (P < 0.0001) and OS (P = 0.042). Multivariate analysis showed that the tumor burden of SLN metastases and Ki 67 proliferative index maintained the statistical significance.

CONCLUSION

Patients with SLN micrometastases or ITC, do not seem to have a worse DFS or OS compared with SLN negative cases. There is a significant decrease in DFS and OS in patients with macrometastatic disease in the SLN.

Are cytokeratin-positive cells in sentinel lymph nodes of patients with invasive breast carcinomas up to 5 mm usually insignificant?

AIMS

It is known that sentinel lymph nodes (SLN) may be falsely positive due to displaced epithelial cells, particularly in cases with an underlying intraductal papilloma. Given the low metastatic rate in pT1a carcinomas, we aimed to investigate the effect of this phenomenon on staging.

METHODS AND RESULTS

Using morphology and immunohistochemistry, we classified the epithelial cells in the SLN in 39 cases of pT1a carcinoma as positive for carcinoma in six, negative in 26 and undetermined in seven. Comparative morphology and immunohistochemistry (using oestrogen receptor, ER) showed complete concordance between the primary carcinoma and SLN in the positive cases, and discordance in the negative cases. The primary tumours in the negative cases were ER-positive except one, in contrast to the SLN cytokeratin-positive (CK(+) ) cells, which were ER-negative. The exception was a case with a Her2-positive primary, in which the SLN CK(+) cells did not stain for Her2. In these cases considered SLN-negative, either displacement (19 cases) or an intraductal papilloma (20 cases) was identified. Two cases showed displacement of benign and malignant cells in the biopsy. Seven cases were indeterminate due to the small number of SLN CK(+) cells, precluding comparison with the primary.

CONCLUSION

Given the low rate of metastases in pT1a carcinomas, the significance of SLN CK(+) cells should be resolved by comparative morphology and immunohistochemistry to prevent erroneous upstaging.

Accuracy of frozen section analysis of sentinel lymph nodes for the detection of Asian breast cancer micrometastasis - experience from Pakistan

BACKGROUND

Intraoperative sentinel lymph node biopsy has now become the standard of care for patients with clinically node negative breast cancer for diagnosis and also in order to determine the need for immediate axillary clearance. Several large scale studies confirmed the diagnostic reliability of this method. However, micrometastases are frequently missed on frozen sections. Recent studies showed that both disease free interval and overall survival are significantly affected by the presence of micrometastatic disease. The aim of this study was to determine the sensitivity and specificity of intraoperative frozen section analysis of sentinel lymph nodes (SLNs) for the detection of breast cancer micrometastasis and to evaluate the status of non-sentinel lymph nodes (non-SLNs) in those patients subjected to further axillary sampling.

MATERIALS AND METHODS

We performed a retrospective study on 154 patients who underwent SLN biopsy from January 2008 till October 2011. The SLNs were sectioned at 2 mm intervals and submitted entirely for frozen sections. Three levels of each section submitted are examined and the results were compared with further levels on paraffin sections.

RESULTS

Overall 40% of patients (62/154) were found to be SLN positive on final (paraffin section) histology, out of which 44 demonstrated macrometastases (>2mm) and 18 micrometastases (<2mm). The overall sensitivity and specificity of frozen section analysis of SLN for the detection of macrometastasis was found to be 100% while those for micrometastasis were 33.3% and 100%, respectively. Moreover 20% of patients who had micrometastases in SLN had positive non-SLNs on final histology.

CONCLUSIONS

Frozen section analysis of SLNs lacks sufficient accuracy to rule out micrometastasis by current protocols. Therefore these need to be revised in order to pick up micrometastasis which appears to have clinical significance. We suggest that this can be achieved by examining more step sections of blocks.

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.

What is the future of axillary surgery for breast cancer?

The Z11 trial demonstrated a subgroup of patients with low axillary burden who do not benefit from axillary lymph node dissection (ALND) at short-term follow-up when treated with adjuvant whole-breast radiotherapy and systemic therapy. We consider the role of sentinel lymph node biopsy (SLNB) and look at and beyond the Z11 trial to consider further imaging studies, which may offer truly minimally invasive management of the axilla and relegate SLNB to the realms of history. Regional lymph node status provides information regarding staging, local control, and prognostic outcomes in all cancers. This information was provided in breast cancer by axillary lymph node dissection (ALND). This changed with the development of sentinel lymph node biopsy (SLNB) [1, 2]. Sentinel lymph nodes (SLNs) are defined as the first lymph nodes receiving lymphatic drainage from the primary tumour and therefore the most likely to harbour metastatic cancer via lymphatic spread. SLNB is now the standard of care in patients with a clinically and radiologically clear axilla in early-stage breast cancer.

Clinical significance and management of sentinel node micrometastasis in invasive breast cancer

Axillary node status is one of the most important prognostic indicators in patients with invasive breast cancer. Sentinel node biopsy allows an exhaustive examination of the lymph node and has led to an increased detection rate of small tumor deposits. Patients with micrometastatic deposits can have nonsentinel node involvement, including macrometastatic deposits. Sentinel node micrometastases are associated with an adverse impact on disease recurrence and survival. Axillary dissection does not offer an advantage in reducing the incidence of disease recurrence or survival. However, the long-term outcomes can be improved with the use of adjuvant chemotherapy, and it would be reasonable to consider systemic treatment in these patients.

Current status of diagnosis and treatment of primary breast cancer in beijing, 2008

OBJECTIVE

To investigate the status of diagnosis and treatment of primary breast cancer in Beijing, 2008.

METHODS

All the patients who were diagnosed as primary breast cancer in Beijing in 2008 were enrolled in this study. Information of these patients, including the features of tumors, clinical diagnosis and treatment was collected, and filled in the well-designed questionnaire forms by trained surveyors. The missing data was partly complemented through telephone interviews.

RESULTS

A total of 3473 Beijing citizens were diagnosed as primary breast cancer (25 patients with synchronal bilateral breast cancer) in Beijing, 2008. Of them 82.09% were symptomatic. 19.02% and 34.11% were diagnosed using fine needle aspiration biopsy (FNAB) and core needle biopsy (CNB), respectively. 15.92% received sentinel lymph node biopsy (SLNB) and 24.27% received breast conserving surgery (BCS). Among 476 cases with Her-2 positive, only 96 received anti-Her-2 therapy. We found that the standardization level varied in hospitals of different grades, with higher level in Grade-III hospitals. Of note, some breast cancer patients received non-standard primary tumor therapy: 65.63% of the patients with ductal carcinoma in situ (DCIS) received axillary lymph node dissection and 36.88% received chemotherapy; 25.89% of the patients underwent breast conserving surgery without margin status; 12.10% of the patients received chemotherapy less than 4 cycles.

CONCLUSION

Although most breast cancer patients received basic medical care, the mode of diagnosis and treatment should be improved and should be standardized in the future in Beijing.

Mouse model of lymph node metastasis via afferent lymphatic vessels for development of imaging modalities

Animal studies of lymph node metastasis are constrained by limitations in the techniques available for noninvasive monitoring of the progression of lymph node metastasis, as well as difficulties in the establishment of appropriate animal models. To overcome these challenges, this study has developed a mouse model of inter-lymph-node metastasis via afferent lymphatic vessels for use in the development of imaging modalities. We used 14- to 18-week-old MRL/MpJ−/lpr/lpr (MRL/lpr) mice exhibiting remarkable systemic lymphadenopathy, with proper axillary lymph nodes (proper-ALNs) and subiliac lymph nodes (SiLNs) that are 6 to 12 mm in diameter (similar in size to human lymph nodes). When KM-Luc/GFP malignant fibrous histiocytoma-like cells stably expressing the firefly luciferase gene were injected into the SiLN, metastasis could be detected in the proper-ALN within 3 to 9 days, using in vivo bioluminescence imaging. The metastasis route was found to be via the efferent lymphatic vessels of the SiLN, and metastasis incidence depended on the number of cells injected, the injection duration and the SiLN volume. Three-dimensional contrast-enhanced high-frequency ultrasound imaging showed that the blood vessel volume and density in the metastasized proper-ALN significantly increased at 14 days after tumor cell inoculation into the SiLN. The present metastasis model, with lymph nodes similar in size to those of humans, has potential use in the development of ultrasound imaging with high-precision and high-sensitivity as well as other imaging modalities for the detection of blood vessels in lymph nodes during the progression of metastasis.

Three-dimensional quantitative ultrasound for detecting lymph node metastases

PURPOSE

Detection of metastases in lymph nodes (LNs) is critical for cancer management. Conventional histological methods may miss metastatic foci. To date, no practical means of evaluating the entire LN volume exists. The aim of this study was to develop fast, reliable, operator-independent, high-frequency, quantitative ultrasound (QUS) methods for evaluating LNs over their entire volume to effectively detect LN metastases.

METHODS

We scanned freshly excised LNs at 26 MHz and digitally acquired echo-signal data over the entire three-dimensional (3D) volume. A total of 146 LNs of colorectal, 26 LNs of gastric, and 118 LNs of breast cancer patients were enrolled. We step-sectioned LNs at 50-μm intervals and later compared them with 13 QUS estimates associated with tissue microstructure. Linear-discriminant analysis classified LNs as metastatic or nonmetastatic, and we computed areas (Az) under receiver-operator characteristic curves to assess classification performance. The QUS estimates and cancer probability values derived from discriminant analysis were depicted in 3D images for comparison with 3D histology.

RESULTS

Of 146 LNs of colorectal cancer patients, 23 were metastatic; Az = 0.952 ± 0.021 (95% confidence interval [CI]: 0.911-0.993); sensitivity = 91.3% (specificity = 87.0%); and sensitivity = 100% (specificity = 67.5%). Of 26 LNs of gastric cancer patients, five were metastatic; Az = 0.962 ± 0.039 (95% CI: 0.807-1.000); sensitivity = 100% (specificity = 95.3%). A total of 17 of 118 LNs of breast cancer patients were metastatic; Az = 0.833 ± 0.047 (95% CI: 0.741-0.926); sensitivity = 88.2% (specificity = 62.5%); sensitivity = 100% (specificity = 50.5%). 3D cancer probability images showed good correlation with 3D histology.

CONCLUSIONS

These results suggest that operator- and system-independent QUS methods allow reliable entire-volume LN evaluation for detecting metastases. 3D cancer probability images can help pathologists identify metastatic foci that could be missed using conventional methods.