Immunophenotypic profile of tumor buds in breast cancer

Tumor Budding in Invasive Breast Carcinoma, No Special Type: Association With Pathological Prognostic Factors and Comparison of 2 Different Scoring Systems

Introduction. In contrast to colorectal carcinoma, the significance of tumor budding in breast carcinoma is not established. The X20 objective which is used to assess tumor budding in colorectal carcinoma, is not widely available in countries with limited resources. This study aimed to determine the prevalence of tumor budding and its associations with pathological prognostic factors in invasive breast carcinoma-no special type (IBC-NST), and to assess the correlation between the tumor budding observed using ×20 and ×40 objectives. Methods. A total of 349 excision specimens of IBC-NST were studied. Tumor budding was defined as a single cell/cluster of up to 4 cells at the invasive front and was assessed in hotspots at the advancing edge of the tumor using ×20 and ×40 objectives. Tumor budding was categorized into low (<5/0.785 mm2), intermediate (5-9/0.785 mm2), and high budding (≥10/0.785 mm2) for ×20 objective and low (≤4/0.196 mm2) and high (≥5/0.196 mm2) for ×40 objective based on the number of buds per hotspot. The association between tumor budding and prognostic factors was analyzed with Mann-Whitney U test, Kruskal-Wallis test, χ2 test, and logistic regression. Correlation between tumor budding in ×20 and ×40 objectives was analyzed with Pearson correlation test. Results. The prevalence of tumor budding was 72.5%. There was a significant correlation between the number of buddings observed in ×40 objective and ×20 objective (0.958). High tumor budding observed in both objectives was significantly associated with size (P < .001), lymphovascular invasion (P < .001), perineural invasion (P < .001), lymph node status (P < .001), number of lymph nodes (P < .001), T stage (P < .001), and N stage (P < .001) on univariate analysis, but only lymph node positivity (P < .001) showed significant association on multivariate analysis. Conclusion. Tumor budding assessed with ×20 and ×40 objectives showed a significant correlation and was significantly associated lymph node metastasis on multivariate analysis.

Tumor budding in invasive breast carcinoma: correlation with clinicopathological parameters, hormone receptor status, and survival: an observational study

OBJECTIVE

Tumor budding is currently thought to be associated with worse prognosis. This study aims to examine tumor budding in invasive ductal-type breast carcinoma and its relationship with other clinicopathological parameters and overall survival.

METHODS

All the H&E slides of 198 patients were re-evaluated for the histological grade, angiolymphatic invasion, perineural invasion, lymph node status, extranodal extension, multicentricity, pT, presence of the tumor budding, tumor budding score (i.e., low, intermediate, or high). Overall survival was considered the period after surgery until death. SPSS was used for statistical analysis.

RESULTS

Tumor budding was identified in 98 (49.5%) patients. Tumor budding score was low in 41 (41.8%) of 98 cases, intermediate in 25 (25.5%), and high in 32 (32.7%). We determined a strong correlation between tumor budding and poor prognostic variables such as tumor size, pT stage, angiolymphatic invasion, perineural invasion, number of metastatic axillary lymph nodes, overall survival, and extranodal tumor extension in metastatic lymph nodes. This strong correlation was also present for the tumor budding score.

CONCLUSION

Tumor budding may be a prognostic indicator for breast cancer.

Tumour budding is a novel marker in breast cancer: the clinical application and future prospects

Breast cancer (BC) is a group of markedly heterogeneous tumours. There are many subtypes with different biological behaviours and clinicopathological characteristics, leading to significantly different prognosis. Despite significant advances in the treatment of BC, early metastatic is a critical factor for poor prognosis in BC patients. Tumour budding (TB) is considered as the first step process of tumour metastasis and is related to the epithelial-mesenchymal transition (EMT). TB has been observed in a variety of cancers, such as colorectal and gastric cancer, and had been considered as a distinct clinicopathological characteristics for early metastasis. However, TB evaluation standards and clinical application are not uniform in BC, as well as its molecular mechanism is not fully understood. Here, we reviewed the interpretation criteria, mechanism, clinicopathological characteristics and clinical application prospects of TB in BC. Key messagesCurrently, tumour budding is a poor prognosis for various solid tumours, also in breast cancer.Tumour budding is based on epithelial-mesenchymal transition and tumour microenvironment factors and is presumed to be an early step in the metastatic process.Breast cancer tumour budding still needs multi-centre experiments. We summarize the current research on breast cancer tumour budding, analyse the method of discriminating breast cancer tumour budding and explore the prognostic role and mechanism in breast cancer.

A Retrospective Study of Association of Tumor Budding, Tumor Microenvironment, and Clinicopathological Characteristics of Invasive Breast Carcinoma

Background Tumor budding (TB) has been identified in many solid cancers and thought to be involved in invasion and is the initial step in the metastatic process. Limited information is available documenting the role of tumor budding in breast carcinoma. With this aim, the present study evaluates the association of tumor budding, tumor microenvironment, and its correlation with clinicopathologic parameters.

Materials and Methods A total of 102 cases were archived and evaluated for peripheral and intra tumoral budding along with tumor microenvironment on hematoxylin and eosin (H&E) slides.

Statistical Analysis Correlation between tumor budding, tumor microenvironment, and other classical clinicopathological parameters was studied by Chi-square test. A p-value less than 0.05 was considered significant.

Results Females constituted 99 cases out of 102 and 3 were males. We found 55.9% and 44.1% of patients in the age group less than or equal to 50 and greater than 50, respectively. Also, 65.6% of cases presented with small tumor size less than or equal to 5 cm, 80.39% with lymph node metastasis, and 76.4% with lympho-vascular emboli. High peripheral tumoral budding (PTB) was seen in 45.10%, low peripheral tumoral budding in 54.9%, high ITB in 53.9%, and low ITB in 46.1%. Necrosis was found only in 39.21%. Significant statistical association of PTB was found with lymph node metastasis, lymphovascular emboli, and tumor necrosis, whereas ITB with tumor grade, lymph node metastasis, lympho-vascular emboli, and necrosis. Both PTB and ITB showed no statistically significant correlation with age and size of the tumor.

Conclusion Tumor budding is an independent adverse prognostic factor in invasive breast carcinoma. However, further work is needed to establish a standard method for the quantification of this parameter, which will help in effective stratification of patients in terms of disease-free survival and likely outcome.

Establishment and Clinical Application of an Artificial Intelligence Diagnostic Platform for Identifying Rectal Cancer Tumor Budding

Tumor budding is considered a sign of cancer cell activity and the first step of tumor metastasis. This study aimed to establish an automatic diagnostic platform for rectal cancer budding pathology by training a Faster region-based convolutional neural network (F-R-CNN) on the pathological images of rectal cancer budding. Postoperative pathological section images of 236 patients with rectal cancer from the Affiliated Hospital of Qingdao University, China, taken from January 2015 to January 2017 were used in the analysis. The tumor site was labeled in Label image software. The images of the learning set were trained using Faster R-CNN to establish an automatic diagnostic platform for tumor budding pathology analysis. The images of the test set were used to verify the learning outcome. The diagnostic platform was evaluated through the receiver operating characteristic (ROC) curve. Through training on pathological images of tumor budding, an automatic diagnostic platform for rectal cancer budding pathology was preliminarily established. The precision–recall curves were generated for the precision and recall of the nodule category in the training set. The area under the curve = 0.7414, which indicated that the training of Faster R-CNN was effective. The validation in the validation set yielded an area under the ROC curve of 0.88, indicating that the established artificial intelligence platform performed well at the pathological diagnosis of tumor budding. The established Faster R-CNN deep neural network platform for the pathological diagnosis of rectal cancer tumor budding can help pathologists make more efficient and accurate pathological diagnoses.

Joint Tumor Bud-MMP/TIMP Count at the Invasive Front Improves the Prognostic Evaluation of Invasive Breast Carcinoma

BACKGROUND

Tumor budding is a histological phenomenon consisting of the formation of small clusters of one to five undifferentiated malignant cells detached from the main tumor mass which are observed in the tumor stroma. In the present study, we investigated the prognostic significance of tumor budding in breast cancer and its relationship with the expressions of matrix metalloproteases (MMPs) and their tissue inhibitors (TIMPs).

METHODS

The number of buds was counted in whole-tissue sections from 153 patients with invasive ductal carcinomas who underwent a long follow-up period. In addition, an immunohistochemical study of MMP-9, -11, and -14 TIMP-1 and -2 expression by cell types at the invasive tumor front was carried out.

RESULTS

There was a wide variability in the number of buds among tumors, ranging from 0 to 28 (median = 5). Tumor budding count ≥ 4 was the optimal cut-off to predict both relapse-free and overall survival. High-grade tumor budding was associated with MMP/TIMP expression by cancer-associated fibroblasts. In addition, we found that the combination of tumor budding grade with MMP/TIMP expression by stromal cells, and especially with MMP-11 expression by mononuclear inflammatory cells, significantly improved the prognostic evaluation.

CONCLUSION

High-grade tumor budding is associated with a more aggressive tumor phenotype, which, combined with MMP/TIMP expression by stromal cells at the invasive front of the tumor, identifies patients with poor prognosis.

Hypoxia, partial EMT and collective migration: Emerging culprits in metastasis

Epithelial-mesenchymal transition (EMT) is a cellular biological process involved in migration of primary cancer cells to secondary sites facilitating metastasis. Besides, EMT also confers properties such as stemness, drug resistance and immune evasion which can aid a successful colonization at the distant site. EMT is not a binary process; recent evidence suggests that cells in partial EMT or hybrid E/M phenotype(s) can have enhanced stemness and drug resistance as compared to those undergoing a complete EMT. Moreover, partial EMT enables collective migration of cells as clusters of circulating tumor cells or emboli, further endorsing that cells in hybrid E/M phenotypes may be the 'fittest' for metastasis. Here, we review mechanisms and implications of hybrid E/M phenotypes, including their reported association with hypoxia. Hypoxia-driven activation of HIF-1α can drive EMT. In addition, cyclic hypoxia, as compared to acute or chronic hypoxia, shows the highest levels of active HIF-1α and can augment cancer aggressiveness to a greater extent, including enriching for a partial EMT phenotype. We also discuss how metastasis is influenced by hypoxia, partial EMT and collective cell migration, and call for a better understanding of interconnections among these mechanisms. We discuss the known regulators of hypoxia, hybrid EMT and collective cell migration and highlight the gaps which needs to be filled for connecting these three axes which will increase our understanding of dynamics of metastasis and help control it more effectively.

Tumour budding in solid cancers

Tumour budding is an emerging prognostic biomarker in colorectal cancer (CRC) and other solid cancers. Tumour buds are usually defined as isolated single cancer cells or clusters of up to four cancer cells located at the invasive tumour front. The prognostic value of tumour budding is now supported by a large body of evidence, whereas the utility of this phenotype as a predictive biomarker remains under investigation. The application of tumour budding indices in clinical practice requires a standardized scoring system that can be tailored to specific tumour types and clinical scenarios. In the context of CRC, tumour budding can be assessed according to the method agreed at the International Tumour Budding Consensus Conference (ITBCC) in 2016. Using the ITBCC scoring system, tumour budding is an independent predictor of lymph node metastasis in patients with pT1 CRC and of unfavourable survival in patients with stage II colon cancer. Regardless of the clinical scenario or tumour type, the assertion that 'the more tumour buds, the worse the clinical outcome' applies. In this Review, we provide an overview of tumour budding in solid cancers, highlighting the molecular and biological aspects of this phenomenon, including its associations with epithelial-mesenchymal transition and features of the tumour microenvironment. We also describe the available evidence demonstrating the value of tumour budding as a biomarker across various solid cancers.

HER2 in stemness and epithelial-mesenchymal plasticity of breast cancer

Breast cancer had been the first non-hematologic malignancy where sub-types based on molecular characterization had entered clinical practice. HER2 over-expression, due to either gene amplification or protein up-regulation, defines one of these sub-types and is clinically exploited by addition of HER2-targeted treatments to the regimens of treatment. Nevertheless, in many occasions HER2-positive cancers are resistant or become refractory to these therapies. Several mechanisms, such as activation of alternative pathways or loss of expression of the receptor in cancer cells, have been proposed as the cause of these therapeutic failures. Cancer stem cells (CSCs, alternatively called tumor-initiating cells) comprise a small percentage of the tumor cells, but are capable of reconstituting and propagating tumors due to their superior intrinsic capacity for regeneration, survival and resistance to therapies. CSCs possess circuits enabling epigenetic plasticity which endow them with the ability to alternate between epithelial and mesenchymal states. This paper will discuss the expression and regulation of HER2 in CSCs of the different sub-types of breast cancer and relationships of the receptor with both the circuits of stemness and epithelial-mesenchymal plasticity. Therapeutic repercussions of the relationship of HER2-initiated signaling with stemness networks will also be proposed.

Prognostic role of tumor budding in breast cancer

Tumor budding, defined as a small number of cancer cells observed in pathology sections detached from the main tumor mass, is a common phenomenon in cancer. It is suggested that cells in buds are in the process of actively moving away from the primary tumor in the first step of metastasis. Tumor budding has been observed in a variety of carcinomas and is best studied in colorectal cancers where it portends poor prognosis. More recently, tumor budding was found to be of prognostic significance in other cancers including breast cancer. Tumor budding in breast cancer is associated with other adverse pathologic factors, such as larger tumor size and lymphovascular invasion, but may have additional independent prognostic value. In the future, standardization of the quantification criteria for tumor budding may further aid in its adoption as a prognostic marker.