Breast Cancer Metastasis to the Axillary Lymph Nodes: Are Changes to the Lymph Node "Soil" Localized or Systemic?

Protocol for perfusing human axillary lymph nodes ex vivo to study structure and function in real time

Lymph nodes regulate immunity and maintain fluid balance in health and disease. Here, we present a protocol that uses normothermic perfusion to sustain patient-derived lymph nodes ex vivo for up to 24 h to study their structure and function. We describe steps for setting up both thermoregulatory and perfusion circuits, cannulating human lymph nodes, and perfusion. This protocol can be used to study how human lymph nodes change in cancer and other diseases, and/or in response to perturbations, including drugs. For complete details on the use and execution of this protocol, please refer to Barrow-McGee et al.1.

Association of chemokine (CXC motif) receptor 4 expression with lymphovascular invasion and lymph node metastasis of invasive breast cancer

BACKGROUND

The histological tumor grade influences the prognosis of breast cancer. In metastatic breast cancer, stromal cells produce chemokine (CXC motif) ligand 12 or stromal cell-derived factor-1 as a chemoattractant, which binds to chemokine (CXC motif) receptor 4 (CXCR4) expressed by breast cancer cells.

OBJECTIVE

This study aimed to determine the expression of CXCR4 in invasive breast cancer in relation to lymphovascular invasion (LVI) and lymph node metastasis.

METHODS

This observational study retrospectively investigated a paraffin block archived sample diagnosed with invasive breast cancer. The results of immunohistochemical staining with CXCR4 antibody and expression analysis were evaluated using light microscopy. The data were statistically analyzed using the chi-square test and presented in a table using SPSS version 18. P-values of <0.05 were considered statistically significant.

RESULTS

The expression of CXCR4 was significantly associated with the incidence of LVI and lymph node metastasis in invasive breast cancer (both p = 0.001).

CONCLUSIONS

The results show that the expression of CXCR4 varies and support its decisive role in the incidence of LVI and lymph node metastasis in invasive breast cancer.

One Step Nucleic Acid Amplification (OSNA) Lysate Samples Are Suitable to Establish a Transcriptional Metastatic Signature in Patients with Early Stage Hormone Receptors-Positive Breast Cancer

The One Step Nucleic Acid Amplification (OSNA) is being adopted worldwide for sentinel lymph nodes (SLNs) staging in breast cancer (BC). As major disadvantage, OSNA precludes prognostic information based on structural evaluation of SLNs. Our aim is to identify biomarkers related to tumor-microenvironment interplay exploring gene expression data from the OSNA remaining lysate. This study included 32 patients with early stage hormone receptors-positive BC. Remaining OSNA lysates were prepared for targeted RNA-sequencing analysis. Identification of differentially expressed genes (DEGs) was performed by DESeq2 in R and data analysis in STATA. The results show that, in metastatic SLNs, several genes were upregulated: KRT7, VTCN1, CD44, GATA3, ALOX15B, RORC, NECTIN2, LRG1, CD276, FOXM1 and IGF1R. Hierarchical clustering analysis revealed three different clusters. The identified DEGs codify proteins mainly involved in cancer aggressiveness and with impact in immune response. The overexpression of the immune suppressive genes VTCN1 and CD276 may explain that no direct evidence of activation of immune response in metastatic SLNs was found. We show that OSNA results may be improved incorporating microenvironment-related biomarkers that may be useful in the future for prognosis stratification and immunotherapy selection. As OSNA assay is being implemented for SLNs staging in other cancers, this approach could also have a wider utility.

Proteomics of Sentinel Lymph Nodes in Early Breast Cancer for Identification of Thymidylate Synthase as a Potential Biomarker to Flag Metastasis: A Preliminary Study

Introduction

Breast cancer is the second most common cancer in women across the world. Some of the patients who present in the early stage of disease are affected by metastasis to the axillary group of lymph nodes. The first among this group that is affected is called as sentinel lymph node, and its diagnosis is crucial for the staging of cancer thereby dictating the type of surgical therapy. Therefore, the sentinel lymph node status provides the most relevant information to the surgeon and patient prognosis. The expanded utilization of breast conservation surgery has declined the morbidity associated with mastectomy and axillary lymph node surgery. Recent interest is, therefore, centered on techniques that allow accurate assessment of the sentinel lymph node metastasis. A current procedure such as sentinel lymph node biopsy (SLNB) that is used to assess axillary lymph node metastasis is neither specific nor sensitive, and besides, it is time-consuming.

Objective

To compare the protein profiles between metastatic and non-metastatic lymph nodes to identify a biomarker that can flag lymph node metastasis.

Materials and Methods

Women with early breast cancer were screened using mammography imaging and recruited to the study. Surgical resection was done to remove the breast tissue, and sentinel lymph node was identified using fluorescein and methylene blue tracer. Lymph node was sliced, and one set was sent for histopathology, which was considered the gold standard to assess the metastatic status of the lymph node. One set of slices was taken for proteomic experiments. Proteins were labelled with fluorescent cyanine tags and were subjected to difference gel electrophoresis experiment. Differentially expressed spots that had at least a twofold relative ratio and consistent pattern across three sets of biological replicate experiments were marked. Gel spots were trypsin digested and identified on mass spectrometry machine. Validation study was done by Western blot experiment on the same set of samples.

Results

Thymidylate synthase has a twofold higher expression in the metastatic sentinel lymph nodes as compared to non-metastatic lymph nodes in early breast cancer patients.

Conclusion

Differential in gel expression proteomics is an ideal platform for the identification of potential protein biomarker candidates that can differentiate metastatic from non-metastatic lymph nodes in early breast cancer. The identification of thymidylate synthase offers a scope to develop an on-table diagnostic kit to assess the status of sentinel lymph nodes during mastectomy procedure to guide surgical management of axillary lymph nodes in early breast cancer.

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Association between axillary lymph node involvement and clinicopathological features of breast cancer among Indonesian women

BACKGROUND Some clinicopathological features play roles in the spread of breast cancer to axillary lymph node (ALN). However, their roles as predictive factors are not well-established. This study was conducted to determine the correlation between the clinicopathological features of breast cancer and the risk of ALN involvement in Indonesian women. METHODS This cross-sectional study was conducted in Margono Soekarjo Hospital using archival data from January 2017 to June 2018. All subjects with breast cancer who had undergone modified radical mastectomies without any evidence of distant metastasis were included. Chi-square and Fisher’s exact tests were performed to assess the relationship between ALN involvement and age, menopausal status, laterality, tumor size, tumor stage, histological type, tumor grade, lymphovascular space invasion (LVSI), skin or nipple infiltration, perineural invasion, estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 status. The odds ratio of each variable was evaluated using ordinal regression analysis. RESULTS Stage 3 breast cancer had the worst status of ALN involvement compared with stage 1 (OR = 3.49; 95% CI = 1.51–8.08) and stage 2 (OR = 3.04; 95% CI = 1.32–6.98). Likewise, positive LVSI also had the worst status of ALN involvement compared with negative LVSI (OR = 8.68; 95% CI = 4.23–17.81). CONCLUSIONS Tumor stage and LVSI could be considered as independent predictive factors of ALN involvement in patients with breast cancer, especially among Indonesian women.

Molecular patterns of cancer colonisation in lymph nodes of breast cancer patients

Lymph node (LN) metastasis is an important prognostic parameter in breast carcinoma, a crucial site for tumour–immune cell interaction and a gateway for further dissemination of tumour cells to other metastatic sites. To gain insight into the underlying molecular changes from the pre-metastatic, via initial colonisation to the fully involved LN, we reviewed transcriptional research along the evolving microenvironment of LNs in human breast cancers patients. Gene expression studies were compiled and subjected to pathway-based analyses, with an emphasis on immune cell-related genes. Of 366 studies, 14 performed genome-wide gene expression comparisons and were divided into six clinical-biological scenarios capturing different stages of the metastatic pathway in the LN, as follows: metastatically involved LNs are compared to their patient-matched primary breast carcinomas (scenario 1) or the normal breast tissue (scenario 2). In scenario 3, uninvolved LNs were compared between LN-positive patients and LN-negative patients. Scenario 4 homed in on the residual uninvolved portion of involved LNs and compared it to the patient-matched uninvolved LNs. Scenario 5 contrasted uninvolved and involved LNs, whilst in scenario 6 involved (sentinel) LNs were assessed between patients with other either positive or negative LNs (non-sentinel).

Gene lists from these chronological steps of LN metastasis indicated that gene patterns reflecting deficiencies in dendritic cells and hyper-proliferation of B cells parallel to tumour promoting pathways, including cell adhesion, extracellular matrix remodelling, cell motility and DNA repair, play key roles in the changing microenvironment of a pro-metastatic to a metastatically involved LN. Similarities between uninvolved LNs and the residual uninvolved portion of involved LNs hinted that LN alterations expose systemic tumour-related immune responses in breast cancer patients. Despite the diverse settings, gene expression patterns at different stages of metastatic colonisation in LNs were recognised and may provide potential avenues for clinical interventions to counteract disease progression for breast cancer patients.

Exosome-mediated delivery of MALAT1 induces cell proliferation in breast cancer

Background

Breast cancer is the most common cancer in women worldwide. Cancer-secreted exosomes have recently been recognized as important mediators of intercellular communication. The aim of this study was to determine the role of exosomal long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in breast cancer progression.

Materials and methods

Breast cancer specimens were obtained with informed consent from patients. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect MALAT1 expression, and cellular proliferation was measured using cell counting kit-8 (CCK-8) assay.

Results

MALAT1 was highly expressed in breast cancer tissues and associated with disease progression. Breast cancer exosomes promoted cell proliferation and exosome-mediated MALAT1 to induce cell proliferation.

Conclusion

These findings indicated that exosomal MALAT1 could regulate cancer progression and represent a novel strategy for overcoming breast cancer.