The prognostic significance of inflammation and medullary histological type in invasive carcinoma of the breast

Role of Ultrasonographic and Clinicopathological Characteristics in Assessing Stromal Tumor-Infiltrating Lymphocyte Density in Triple-Negative Breast Cancer

Background

A high density of stromal tumor-infiltrating lymphocytes (sTILs) is positively correlated with the pathological complete response rate and favorable survival in patients with triple-negative breast cancer (TNBC). Heterogeneity in stromal lymphocyte distribution and limited tumor sampling may affect the accuracy of sTIL quantification in biopsy samples from patients receiving neoadjuvant therapy. Thus, identifying additional biomarkers to complement sTIL evaluation is essential.

Aims

To identify biomarkers that could be used to complement sTILs evaluation.

Study Design

Retrospective cohort study.

Methods

A total of 162 patients with invasive TNBC were enrolled in the study. The following data were gathered: sTIL density, Ki67, nuclear grades of cancer cells, lymphovascular invasion status, the American Joint Committee on Cancer stage, axillary lymph node metastasis status, and ultrasonographic parameters of the tumor (size, shape, orientation, margin, internal echo pattern, posterior feature, and vascularity). The relationship between sTIL density and ultrasonographic or clinicopathological characteristics was investigated using both continuous and categorical analyses.

Results

Posterior features of the primary tumors was associated with sTIL density (p = 0.038). Additionally, the Ki67 levels and nuclear grades were also associated with sTIL density (p < 0.001 and p = 0.024, respectively). When stratified according to a 20% cut-off of sTIL density, the posterior features of primary tumors, Ki67 levels, and nuclear grades significantly differed between the high and low sTIL density tumors. Tumors with high Ki67 levels were more likely to exhibit high sTIL density than low sTIL density [odds ratio (OR): 2.75, p = 0.021]. Furthermore, nuclear grade III tumors demonstrated significantly higher sTIL density than nuclear grade I-II tumors (OR: 2.49, p = 0.014). Additionally, tumors with posterior enhancement or no posterior features were more likely to exhibit high sTIL density than tumors with acoustic shadows (OR: 2.91, p = 0.028; OR: 2.74, p = 0.022, respectively).

Conclusion

Low sTIL density is frequently observed in tumors exhibiting acoustic shadows on ultrasound. However, high sTIL density is more common in tumors with posterior enhancement or no posterior features. Furthermore, high Ki67 levels (> 40%) and high nuclear grades are positively correlated with high sTIL density. This study findings highlight the need for closer surveillance of these biomarkers to complement sTIL evaluation in TNBC.

Tumor-Infiltrating Lymphocytes (TILs) in Breast Cancer: Prognostic and Predictive Significance across Molecular Subtypes

Tumor-infiltrating lymphocytes (TILs) are pivotal in the immune response against breast cancer (BC), with their prognostic and predictive significance varying across BC subtypes. In triple-negative BC (TNBC), higher TIL levels correlate with improved prognosis and treatment response, guiding therapeutic strategies and potentially offering avenues for treatment de-escalation. In metastatic TNBC, TILs identify patients with enhanced immunotherapy response. HER2+ BC, similar to TNBC, exhibits positive correlations between TILs and treatment response, especially in neoadjuvant settings. Luminal BC generally has low TILs, with limited prognostic impact. Single hormone receptor-positive BCs show distinct TIL associations, emphasizing subtype-specific considerations. TILs in ductal carcinoma in situ (DCIS) display ambiguous prognostic significance, necessitating further investigation. Standardizing TIL assessment methods is crucial for unlocking their full potential as biomarkers, guiding treatment decisions, and enhancing patient care in BC.

A risk stratification model to predict chemotherapy benefit in medullary carcinoma of the breast: a population-based SEER database

Whether patients with medullary breast carcinoma (MBC) receive chemotherapy is controversial. Therefore, the aim of our study was to screen out patients with MBC who benefit from chemotherapy. We enrolled 618 consecutive patients with MBC from The Surveillance, Epidemiology, and End Results (SEER) database (2010-2018). Cox regression analysis was used to identify independent prognostic factors. Next, a nomogram was constructed and evaluated using calibration plots and the area under the curve (AUC) of receiver operating characteristic (ROC) curves. Kaplan‒Meier curves were used to evaluate the overall survival (OS) benefit of chemotherapy in different risk groups. A total of 618 MBC patients were involved in our study, and an 8:2 ratio was used to randomly split them into a training cohort (n = 545) and a validation cohort (n = 136). Next, a nomogram predicting 3- and 5-year OS rates was constructed based on the five independent factors (age at diagnosis, T stage, N status, subtype and radiation). The nomogram AUCs for 3- and 5-year OS (training set: 0.793 and 0.797; validation set: 0.781 and 0.823) and calibration plots exhibited good discriminative and predictive ability. Additionally, a novel risk classification system for MBC patients demonstrated that we do not have enough evidence to support the benefit effect of chemotherapy for the high-risk group as the result is not statistically significant (total population: p = 0.180; training set: p = 0.340) but could improve OS in the low-risk group (total population: p = 0.001; training set: p = 0.001). Our results suggested that chemotherapy should be selected more carefully for high-risk groups based on a combination of factors and that the possibility of exemption from chemotherapy should be confirmed by more clinical trials in the future.

The tale of TILs in breast cancer: A report from The International Immuno-Oncology Biomarker Working Group

The advent of immune-checkpoint inhibitors (ICI) in modern oncology has significantly improved survival in several cancer settings. A subgroup of women with breast cancer (BC) has immunogenic infiltration of lymphocytes with expression of programmed death-ligand 1 (PD-L1). These patients may potentially benefit from ICI targeting the programmed death 1 (PD-1)/PD-L1 signaling axis. The use of tumor-infiltrating lymphocytes (TILs) as predictive and prognostic biomarkers has been under intense examination. Emerging data suggest that TILs are associated with response to both cytotoxic treatments and immunotherapy, particularly for patients with triple-negative BC. In this review from The International Immuno-Oncology Biomarker Working Group, we discuss (a) the biological understanding of TILs, (b) their analytical and clinical validity and efforts toward the clinical utility in BC, and (c) the current status of PD-L1 and TIL testing across different continents, including experiences from low-to-middle-income countries, incorporating also the view of a patient advocate. This information will help set the stage for future approaches to optimize the understanding and clinical utilization of TIL analysis in patients with BC.

Triple-negative breast cancer and basal-like subtype : Pathology and targeted therapy

Triple-negative breast cancer (TNBC) is a heterogenous disease. For personalized medicine, it is essential to identify and classify tumor subtypes to develop effective therapeutic strategies. Although gene expression profiling has identified several TNBC subtypes, classification of these tumors remains complex. Most TNBCs exhibit an aggressive phenotype, but some rare types have a favorable clinical course. In this review, we summarize the classification and characteristics related to the various TNBC subtypes, including the rare types. Therapeutic methods that are suitable for each subtype are also discussed. Of the intrinsic breast cancer subtypes identified by gene expression analysis, the basal-like subtype specifically displayed decreased expression of an estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) cluster. We also present results that characterize the TNBC and basal-like phenotypes. TNBC may be categorized into four major classes : basal-like, immune-enriched, mesenchymal, and luminal androgen receptor. Therapeutic strategies for each subtype have been proposed along with newly approved targeted therapies for TNBC, such as immune checkpoint inhibitors. Understanding the classification of TNBC based on gene expression profiling in association with clinicopathological factors will facilitate accurate pathological diagnosis and effective treatment selection. J. Med. Invest. 68 : 213-219, August, 2021.

Specific cell differentiation in breast cancer: a basis for histological classification

Breast parenchyma progenitor cells show a high degree of phenotypic plasticity reflected in the wide range of morphology observed in benign and malignant breast tumours. Although there is evidence suggesting that all breast cancer (BC) arises from a common epithelial progenitor or stem cell located at the terminal duct lobular units (TDLUs), BC shows a broad spectrum of morphology with extensive variation in histological type and grade. This is related to the complexity of BC carcinogenesis including initial genetic changes in the cell of origin, subsequent genetic and epigenetic alterations and reprogramming that occur at various stages of BC development and the interplay with the surrounding microenvironment, factors which influence the process of differentiation. Differentiation in BC determines the morphology, which can be measured using histological grade and tumour type. Histological grade, which measures the similarity to the TDLUs, reflects the degree of differentiation whereas tumour type reflects the type of differentiation. Understanding BC phenotypic differentiation facilitates the accurate diagnosis and histological classification of BC with corresponding clinical implications in terms of disease behaviour, prognosis and management plans. In this review, we highlight the potential pathways that BC stem cells follow resulting in the development of different histological types of BC and how knowledge of these pathways impacts our ability to classify BC in diagnostic practice. We also discuss the role of cellular differentiation in producing metaplastic and neuroendocrine carcinomas of the breast and how the latter differ from their counterparts in other organs, with emphasis on clinical relevance.

Hormone Receptor Status May Impact the Survival Benefit Between Medullary Breast Carcinoma and Atypical Medullary Carcinoma of the Breast: A Population-Based Study

Background

A rare subtype of breast cancer, atypical medullary carcinoma of the breast (AMCB), shows a highly adverse prognosis compared to medullary carcinoma of the breast (MBC). The current study aimed to establish a correlated nomogram for the identification of the prognostic factors of AMCB and MBC.

Methods

Kaplan–Meier and Cox regression analyses were applied to data acquired from the Surveillance, Epidemiology and End Results (SEER) database for 2004 to 2013 to analyse tumour characteristics and overall survival. Propensity score matching (PSM) analysis was performed to determine the overall survival (OS) among those with AMCB and MBC. A predictive nomogram was created, and the concordance index (C-index) was used to predict accuracy and discriminative ability.

Results

A total of 2,001 patients from the SEER database were diagnosed with MBC between 2004 and 2013, including 147 patients diagnosed with AMCB. The number of diagnoses gradually increased in both groups. Cox analysis of multivariate and Kaplan–Meier analysis showed that older age (HR = 3.005, 95% CI 1.906–4.739) and later stage were significantly associated with poor prognosis, while cancer-directed surgery was an independent protective factor (HR = 0.252, 95% CI 0.086–0.740). In the HR-negative stratification analysis, older age (HR = 2.476, 95% CI 1.398–4.385), later stage and histological type (HR=0.381, 95% CI 0.198-0.734) were found to be independent prognostic factors for low standard survival. The log-rank analysis demonstrated significantly worse prognostic factors for patients with AMCB than for those with MBC (P = 0.004). A nomogram (C-index for survival = 0.75; 95% CI 0.69–0.81) was established from four independent prognostic factors after complete identification.

Conclusions

MBC is rare, and cancer-directed surgery, older age, and later stage are independently linked with prognosis. In the HR negative population, AMCB patients show a worse survival gain than those with MBC.

Rare Breast Cancer Subtypes

PURPOSE OF REVIEW

Breast cancer is a collection of diseases including the more common invasive ductal and lobular carcinomas and rarer subtypes of breast cancer. This review summarizes the features of rare breast cancers.

RECENT FINDINGS

Each of the rare tumors has defined pathological and clinical features that impact treatment recommendations. In this review, we summarize these for each rare type of breast cancer and where available we include molecular features of each tumor. Rare subtypes of breast cancer each have unique features. In many cases, data is limited for the optimal treatment approaches.

Molecular Complexity of Lymphovascular Invasion: The Role of Cell Migration in Breast Cancer as a Prototype

Lymphovascular invasion (LVI) is associated with poor outcome in breast cancer (BC); however, its underlying mechanisms remain ill-defined. LVI in BC develops through complex molecular pathways involving not only the interplay with the surrounding microenvironment along with endothelial cells lining the lymphovascular spaces but also changes in the malignant epithelial cells with the acquisition of more invasive and migration abilities. In this review, we focus on the key features that enable tumour cell detachment from the primary niche, their migration and interaction with the surrounding microenvironment as well as the crosstalk with the vascular endothelial cells, which eventually lead to intravasation of tumour cells and LVI. Intravascular tumour cell survival and migration, their distant site extravasation, stromal invasion and growth are part of the metastatic cascade. Cancer cell migration commences with loss of tumour cells' cohesion initiating the invasion and migration processes which are usually accompanied by the accumulation of specific cellular and molecular changes that enable tumour cells to overcome the blockades of the extracellular matrix, spread into surrounding tissues and interact with stromal cells and immune cells. Thereafter, tumour cells migrate further via interacting with lymphovascular endothelial cells to penetrate the vessel wall leading ultimately to intravasation of cancer cells. Exploring the potential factors influencing cell migration in LVI can help in understanding the underlying mechanisms of LVI to identify targeted therapy in BC.

Histologic subtyping affecting outcome of triple negative breast cancer: a large Sardinian population-based analysis

BACKGROUND

Triple Negative breast cancer (TNBC) includes a heterogeneous group of tumors with different clinico-pathological features, molecular alterations and treatment responsivity. Our aim was to evaluate the clinico-pathological heterogeneity and prognostic significance of TNBC histologic variants, comparing "special types" to high-grade invasive breast carcinomas of no special type (IBC-NST).

METHODS

This study was performed on data obtained from TNBC Database, including pathological features and clinical records of 1009 TNBCs patients diagnosed between 1994 and 2015 in the four most important Oncology Units located in different hospitals in Sardinia, Italy. Kaplan-Meier analysis, log-rank test and multivariate Cox proportional-hazards regression were applied for overall survival (OS) and disease free survival (DFS) according to TNBC histologic types.

RESULTS

TNBC "special types" showed significant differences for several clinico-pathological features when compared to IBC-NST. We observed that in apocrine carcinomas as tumor size increased, the number of metastatic lymph nodes manifestly increased. Adenoid cystic carcinoma showed the smallest tumor size relative to IBC-NST. At five-year follow-up, OS was 92.1, 100.0, and 94.5% for patients with apocrine, adenoid cystic and medullary carcinoma, respectively; patients with lobular and metaplastic carcinoma showed the worst OS, with 79.7 and 84.3%, respectively. At ten-years, patients with adenoid cystic (100.0%) and medullary (94.5%) carcinoma showed a favourable prognosis, whereas patients with lobular carcinoma showed the worst prognosis (73.8%). TNBC medullary type was an independent prognostic factor for DFS compared to IBC-NST.

CONCLUSIONS

Our study confirms that an accurate and reliable histopathologic definition of TNBC subtypes has a significant clinical utility and is effective in the therapeutic decision-making process, with the aim to develop innovative and personalized treatments.

Are There Any Clinically Relevant Subgroups of Triple-Negative Breast Cancer in 2018?

The working immunohistochemical definition of triple-negative breast cancer (TNBC) is admittedly reductionist and has only limited usefulness for informing oncologists about therapeutic decisions beyond chemotherapy. Early molecular taxonomies of TNBC based heavily on gene expression profiling, which is not readily available in the clinic today, do not necessarily encompass other molecular targets already incorporated into rationally designed clinical trials. We state that it is possible to delineate five subgroups of TNBC relevant to present-day clinical practice and cover the evidence that lends credence to emerging biomarker-directed treatment strategies for each subgroup.

Tumoral BRD4 expression in lymph node-negative breast cancer: association with T-bet+ tumor-infiltrating lymphocytes and disease-free survival

Background

We previously observed that T-bet+ tumor-infiltrating T lymphocytes (T-bet+ TILs) in primary breast tumors were associated with adverse clinicopathological features, yet favorable clinical outcome. We identified BRD4 (Bromodomain-Containing Protein 4), a member of the  Bromodomain and Extra Terminal domain (BET) family, as a gene that distinguished T-bet+/high and T-bet−/low tumors. In clinical studies, BET inhibitors have been shown to suppress inflammation in various cancers, suggesting a potential link between BRD4 and immune infiltration in cancer. Hence, we examined the BRD4 expression and clinicopathological features of breast cancer.

Methods

The cohort consisted of a prospectively ascertained consecutive series of women with axillary node-negative breast cancer with long follow-up. Gene expression microarray data were used to detect mRNAs differentially expressed between T-bet+/high (n = 6) and T-bet−/low (n = 41) tumors. Tissue microarrays (TMAs) constructed from tumors of 612 women were used to quantify expression of BRD4 by immunohistochemistry, which was analyzed for its association with T-bet+ TILs, Jagged1, clinicopathological features, and disease-free survival.

Results

Microarray analysis indicated that BRD4 mRNA expression was up to 44-fold higher in T-bet+/high tumors compared to T-bet−/low tumors (p = 5.38E-05). Immunohistochemical expression of BRD4 in cancer cells was also shown to be associated with T-bet+ TILs (p = 0.0415) as well as with Jagged1 mRNA and protein expression (p = 0.0171, 0.0010 respectively). BRD4 expression correlated with larger tumor size (p = 0.0049), pre-menopausal status (p = 0.0018), and high Ki-67 proliferative index (p = 0.0009). Women with high tumoral BRD4 expression in the absence of T-bet+ TILs exhibited a significantly poorer outcome (log rank test p = 0.0165) relative to other subgroups.

Conclusions

The association of BRD4 expression with T-bet+ TILs, and T-bet+ TIL-dependent disease-free survival suggests a potential link between BRD4-mediated tumor development and tumor immune surveillance, possibly through BRD4’s regulation of Jagged1 signaling pathways. Further understanding BRD4’s role in different immune contexts may help to identify an appropriate subset of breast cancer patients who may benefit from BET inhibitors without the risk of diminishing the anti-tumoral immune activity.

Associations between genomic stratification of breast cancer and centrally reviewed tumour pathology in the METABRIC cohort

The integration of genomic and transcriptomic profiles of 2000 breast tumours from the METABRIC [Molecular Taxonomy of Breast Cancer International Consortium] cohort revealed ten subtypes, termed integrative clusters (IntClust/s), characterised by distinct genomic drivers. Central histopathology (N = 1643) review was undertaken to explore the relationship between these ten molecular subtypes and traditional clinicopathological features. IntClust subtypes were significantly associated with histological type, tumour grade, receptor status, and lymphocytic infiltration (p < 0.0001). Lymph node status and Nottingham Prognostic Index [NPI] categories were also significantly associated with IntClust subtype. IntClust 3 was enriched for tubular and lobular carcinomas, the latter largely accounting for the association with CDH1 mutations in this cluster. Mucinous carcinomas were not present in IntClusts 5 or 10, but did not show an association with any of the remaining IntClusts. In contrast, medullary-like cancers were associated with IntClust 10 (15/26). Hormone receptor-positive tumours were scattered across all IntClusts. IntClust 5 was dominated by HER2 positivity (127/151), including both hormone receptor-positive (60/72) and hormone receptor-negative tumours (67/77). Triple-negative tumours comprised the majority of IntClust 10 (132/159) and around a quarter of IntClust 4 (52/217). Whilst the ten IntClust subtypes of breast cancer show characteristic patterns of association with traditional clinicopathological variables, no IntClust can be adequately identified by these variables alone. Hence, the addition of genomic stratification has the potential to enhance the biological relevance of the current clinical evaluation and facilitate genome-guided therapeutic strategies.

Hormone receptor status and survival of medullary breast cancer patients. A Turkish cohort

Objectives:

To analyze the relationship between clinical features, hormonal receptor status, and survival in patients who were diagnosed with medullary breast cancer (MBC).

Methods:

Demographic characteristics, histopathological features, and survival statuses of 201 patients diagnosed with MBC between 1995 and 2015 were retrospectively recorded. Survival analyses were conducted with uni- and multivariate cox regression analysis.

Results:

Median follow-up time was 54 (4-272) months. Median patient age at the time of diagnosis was 47 years old (26-90). Of the patients, 91.5% were triple negative. Five-year recurrence free survival time (RFS) rate was 87.4% and overalll survival (OS) rate 95.7%. For RFS, progesterone receptor (PR) negativity, atypical histopathological evaluation, absence of lymphovascular invasion, smaller tumor, lower nodal involvement were found to be favourable prognostic factors by univariate analysis (p<0.05). The PR negativity and smaller tumor were found to be favourable factors by univariate analysis (p<0.05). However, none of these factors were determined as significant independent prognostic factors for OS (p>0.05).

Conclusion:

Turkish MBC patients exhibited good prognosis, which was comparable with survival outcomes achieved in the literature. The PR negativity was related to a better RFS and OS rates.

The Spectrum of Triple-Negative Breast Disease: High- and Low-Grade Lesions

Triple-negative breast cancer is viewed clinically as an aggressive subgroup of breast cancer. In fact, most triple-negative breast cancers are poor-prognosis tumors with a complex genomic landscape. However, triple-negative disease is vastly heterogeneous, encompassing multiple entities with marked genetic, transcriptional, histologic, and clinical differences, with neoplasms in this group ranging from low to high grade. Among the less common low-grade triple-negative lesions, two large subgroups, both with a rather indolent behavior, can be distinguished: a low-grade triple-negative breast neoplasia family, which includes nonobligate precursors of triple-negative breast cancer, and, despite being low-grade, harbors the complex genomic landscape of usual triple-negative breast cancer, and the salivary gland-like tumors of the breast, lacking all the cardinal molecular features of conventional triple-negative breast cancer and underpinned by specific fusion genes or hotspot mutations, which may be of diagnostic and possibly therapeutic utility. Progression to high-grade triple-negative breast cancer likely occurs in both subgroups but at different rates. In this review, we describe the heterogeneity of triple-negative disease, focusing on the histologic and molecular features of the low-grade lesions. Recognition that triple-negative breast cancer is an operational term and that triple-negative disease is heterogeneous and includes low-grade forms driven by distinct sets of genetic alterations is germane to the successful implementation of precision medicine.

Molecular alterations in triple-negative breast cancer-the road to new treatment strategies

Triple-negative breast cancer is a heterogeneous disease and specific therapies have not been available for a long time. Therefore, conventional chemotherapy is still considered the clinical state of the art. Different subgroups of triple-negative breast cancer have been identified on the basis of protein expression, mRNA signatures, and genomic alterations. Important elements of triple-negative breast cancer biology include high proliferative activity, an increased immunological infiltrate, a basal-like and a mesenchymal phenotype, and deficiency in homologous recombination, which is in part associated with loss of BRCA1 or BRCA2 function. A minority of triple-negative tumours express luminal markers, such as androgen receptors, and have a lower proliferative activity. These biological subgroups are overlapping and currently cannot be combined into a unified model of triple-negative breast cancer biology. Nevertheless, the molecular analysis of this disease has identified potential options for targeted therapeutic intervention. This has led to promising clinical strategies, including modified chemotherapy approaches targeting the DNA damage response, angiogenesis inhibitors, immune checkpoint inhibitors, or even anti-androgens, all of which are being evaluated in phase 1-3 clinical studies. This Series paper focuses on the most relevant clinical questions, summarises the results of recent clinical trials, and gives an overview of ongoing studies and trial concepts that will lead to a more refined therapy for this tumour type.

[Evaluation of the immune infiltrate in breast cancer]

Tumour-infiltrating lymphocytes (TIL) are major components of the immune/"inflammatory" infiltrate found in tumour microenvironment. They reflect the intensity and the quality of the immune reaction to cancer. In breast cancer, TIL density and phenotypic profile have been demonstrated to be predictive of response to neoadjuvant treatment and of patient outcome. TIL density, currently the best-developed TIL-related biomarker, is defined as the percentage of tumour stroma surface occupied by TIL. The baseline TIL density of 50% and higher is associated with particularly high rates of pathological complete response to neoadjuvant therapy in triple negative and HER2+ breast cancer, as well as with significantly better recurrence-free and overall survival. Similar predictive and prognostic value has been demonstrated for the ratio between the numbers of CD8+ and FoxP3+ TIL. TIL density and the CD8+/FoxP3+ ratio are promising biomarkers in breast cancer, which could be used in tailoring of neoadjuvant and adjuvant systemic therapy and in selection of patients for different immunotherapy modalities. This article reviews elements of the immune response to cancer, methods of TIL analysis, evidence of TIL' prognostic and predictive value in the current breast cancer management as well as the perspectives for use of TIL' characteristics as biomarkers in breast cancer immunotherapy.

Tumor-Infiltrating Lymphocytes and Breast Cancer: Are Immune Checkpoint Inhibitors Ready for Prime Time in Breast Cancer?

In recent years, results obtained from different studies with large cohorts have revealed a bond between the presence of extensive lymphocytic infiltration and favourable prognostic associations in the early-stage of breast cancer (BC) and high response rates to neoadjuvant chemotherapy. Examiners used tumors from large cohorts of patients who took part in randomized neoadjuvant and adjuvant clinical trials. The importance of tumor infiltrating lymphocytes (TILs) appears to be subtype-specific and varies depending on the histological characteristics of the tumor. TILs have proven to be a good prognostic marker, but only in highly proliferative breast tumors such as triple negative breast tumors (TNBC) or HER 2 positive BC.

In the era when standard, well-known, prognostic and predictive biomarkers are ever changing and the use of molecular profiling analyses are increasing, we are looking for techniques to improve our understanding of tumor biology and improve patient outcome. The relevance of TILs cannot be ignored but needs to be properly evaluated in larger prospective studies which must encompass the parameters set out in previous studies. The use of TILs as prognostic biomarkers in early breast cancer may represent a new dawn, and use of immunotherapy, especially immune checkpoint inhibitors, probably is the future for the breast cancer but it is not yet ready for prime time.

Increased CD4 and CD8-positive T cell infiltrate signifies good prognosis in a subset of triple-negative breast cancer

Tumour-infiltrating lymphocytes (TILs) signify immune response to tumour in a variety of cancers including breast cancer. However, earlier studies examining the clinical significance of TILs in breast cancers have generated mixed results. There are only a few that address the relationship between TILs and clinical outcomes in triple-negative breast cancers (TNBC). The aim of this study is to evaluate the clinical significance of TILs that express CD4 + and CD8 + , in TNBC. Immunohistochemical staining of CD4 and CD8 was performed on tissue microarrays of 164 cases of TNBC. TILs were counted separately as intratumoral when within the cancer cell nests (iTILs) and as stromal when within cancer stroma (sTILs). High CD8 + iTILs and sTILs, and CD4 + iTILs correlated with histologic grade. On Kaplan-Meier analysis, a significantly better survival rate was observed in high CD8 + iTIL (disease-free survival, DFS: P = 0.004, overall survival, OS: P = 0.02) and both high CD4 + iTILs (DFS: P = 0.025, OS: P = 0.023) and sTILs (DFS: P = 0.01, OS: P = 0.002). In multivariate analysis, CD8 + iTILs (DFS: P = 0.0095), CD4 + sTILs (DFS: P = 0.0084; OS: P = 0.0118), and CD4 (high) CD8 (high) CD8 iTILs (DFS: P = 0.0121; OS: P = 0.0329) and sTILs (DFS: P = 0.0295) showed significantly better survival outcomes. These results suggest that high levels of both CD8 + iTILs and CD4 + sTILs as well as CD4 (high) CD8 (high) iTILs and sTILs are independent prognostic factors in TNBC.

Prognostic Role of Adjuvant Chemotherapy in Node-Negative (N0), Triple-Negative (TN), Medullary Breast Cancer (MBC) in the Korean Population

BACKGROUND

Despite the favorable prognosis for medullary breast cancer (MBC), the guidelines for the use of adjuvant chemotherapy for MBC have not been clearly established. This study investigated the prognostic role of adjuvant chemotherapy in Korean patients with node-negative (N0), triple-negative (TN) MBC patients.

METHODS

We included data from 252 patients with N0 TN MBC, obtained from the Korean Breast Cancer Registry database. Patients were categorized as those who did not undergo adjuvant chemotherapy (group I) or those who did (group II). Clinicopathological characteristics, breast cancer-specific survival (BCSS), and overall survival (OS) were compared between the groups. In addition, a subgroup analysis for survival based on tumor size was conducted.

RESULTS

A total of 252 N0 TN MBC patients with tumor sizes >1 cm who were diagnosed between April 1997 and March 2011 were enrolled. The median age was 44.95 years (range, 25-72 years), and the median follow-up period was 93.94 months (range, 23-195 months). Overall, the BCSS and OS in group II (97.3% and 97.3%, respectively) were significantly better compared with those in group I (89.2% and 86.2%, respectively). In the subgroup analysis, in patients with tumors >2 cm in size, those in group II had significant better BCSS and OS (97.5% and 97.5%, respectively) compared with those in group I (78.3% and 73.9%, respectively). In contrast in those with tumors 1-2 cm in size, there were no significant differences in BCSS and OS between the groups (both 97.1% for group I, and 95.2% and 92.9%, respectively for group II). Multivariate analysis revealed that adjuvant chemotherapy significantly improved BCSS (P = 0.009) and OS (P = 0.007), but only for patients with larger tumors (>2 cm).

CONCLUSIONS

In patients with N0 TN MBC, adjuvant chemotherapy had a significant clinical survival benefit, but only in those with tumors >2 cm.

Validation of Intratumoral T-bet+ Lymphoid Cells as Predictors of Disease-Free Survival in Breast Cancer

We previously observed T-bet(+) lymphocytes to be associated with a good prognosis in a cohort of women with familial breast cancer. To validate this finding, we evaluated lymphocyte T-bet expression in an independent unselected prospectively accrued series of women with lymph node-negative breast carcinoma. T-bet and clinicopathologic data were available for 614 women. Hormone receptors, HER2, Ki-67, CK5, EGFR, p53, and T-bet status were determined using IHC and/or biochemical methods. Tumors were assigned to luminal A, luminal B, HER2, and basal subtypes based on the expression of IHC markers. Multiple cutpoints were examined in a univariate penalized Cox model to stratify tumors into T-bet(+/high) and T-bet(-/low). Fisher exact test was used to analyze T-bet associations with clinicopathologic variables, IHC markers, and molecular subtype. Survival analyses were by the Cox proportional hazards model. All tests were two sided. A test with a P value < 0.05 was considered statistically significant. T-bet(+/high) tumor status was significantly associated with large tumor size, high grade, hormone receptor negativity, CK5, EGFR and p53 positivity, high Ki-67, and basal subtype. With a median follow-up of 96.5 months, T-bet(-/low) tumor status was associated with a reduced disease-free survival compared with T-bet(+/high) tumor status in multivariate analysis (P = 0.0027; relative risk = 5.62; 95% confidence intervals, 1.48-50.19). Despite being associated with adverse clinicopathologic characteristics, T-bet(+) tumor-infiltrating lymphoid cells are associated with a favorable outcome. This supports their role in Th1-mediated antitumor activity and may provide insight for the development of new therapeutic strategies.

Oncogene addiction and immunity: clinical implications of tumour infiltrating lymphocytes in breast cancers overexpressing the HER2/neu oncogene

PURPOSE OF REVIEW

To review the evidence that correlates tumour infiltrating lymphocytes, a surrogate biomarker of pre-existing host antitumour immunity, and survival in HER2-overexpressing breast cancers. This is of particular relevance to developing immune biomarkers and harnessing new immunotherapeutics in this breast cancer subtype.

RECENT FINDINGS

Oncogene addiction, in which cancer cells become reliant on a single oncogenic pathway for tumour growth and progression, has traditionally been thought of as a cell intrinsic characteristic. However, increasing evidence from multiple studies exploring the relationship between markers of an antitumour immune response and clinical outcome in HER2-overexpressing breast cancer points to the importance of a permissive microenvironment in oncogene-addicted tumours.

SUMMARY

Characterizing the immune microenvironment in HER2-overexpressing breast cancer has the potential to furnish predictive and prognostic biomarkers that may be useful in routine clinical decision-making. The host-tumour immune interface is emerging as a key aspect of breast cancer biology that is likely to yield novel therapies in the near future.

Markers of progression in early-stage invasive breast cancer: a predictive immunohistochemical panel algorithm for distant recurrence risk stratification

Accurate distant metastasis (DM) prediction is critical for risk stratification and effective treatment decisions in breast cancer (BC). Many prognostic markers/models based on tissue marker studies are continually emerging using conventional statistical approaches analysing complex/dimensional data association with DM/poor prognosis. However, few of them have fulfilled satisfactory evidences for clinical application. This study aimed at building DM risk assessment algorithm for BC patients. A well-characterised series of early invasive primary operable BC (n = 1902), with immunohistochemical expression of a panel of biomarkers (n = 31) formed the material of this study. Decision tree algorithm was computed using WEKA software, utilising quantitative biomarkers' expression and the absence/presence of distant metastases. Fifteen biomarkers were significantly associated with DM, with six temporal subgroups characterised based on time to development of DM ranging from <1 to >15 years of follow-up. Of these 15 biomarkers, 10 had a significant expression pattern where Ki67LI, HER2, p53, N-cadherin, P-cadherin, PIK3CA and TOMM34 showed significantly higher expressions with earlier development of DM. In contrast, higher expressions of ER, PR and BCL2 were associated with delayed occurrence of DM. DM prediction algorithm was built utilising cases informative for the 15 significant markers. Four risk groups of patients were characterised. Three markers p53, HER2 and BCL2 predicted the probability of DM, based on software-generated cut-offs, with a precision rate of 81.1 % for positive predictive value and 77.3 %, for the negative predictive value. This algorithm reiterates the reported prognostic values of these three markers and underscores their central biological role in BC progression. Further independent validation of this pruned panel of biomarkers is therefore warranted.

[Invasive breast cancer: the current WHO classification]

The World Health Organization (WHO) classification of tumors of the breast defines the international standards for tumor categorization and nomenclature. The fourth edition, published in 2012, provides an update on the current knowledge concerning the classification, immunohistology profile, differential diagnosis and genetics of these lesions. Compared to the previous edition, some terms have been modified, some entities were reclassified and some current molecular data have been added. This article focuses on invasive carcinomas. Definitions for histological diagnosis are supplemented by clinical, macroscopic and molecular characteristics as well as prognostic and predictive features.

IL15RA drives antagonistic mechanisms of cancer development and immune control in lymphocyte-enriched triple-negative breast cancers

Despite its aggressive nature, triple-negative breast cancer (TNBC) often exhibits leucocyte infiltrations that correlate with favorable prognosis. In this study, we offer an explanation for this apparent conundrum by defining TNBC cell subsets that overexpress the IL15 immune receptor IL15RA. This receptor usually forms a heterotrimer with the IL2 receptors IL2RB and IL2RG, which regulates the proliferation and differentiation of cytotoxic T cells and NK cells. However, unlike IL15RA, the IL2RB and IL2RG receptors are not upregulated in basal-like TNBC breast cancer cells that express IL15RA. Mechanistic investigations indicated that IL15RA signaling activated JAK1, STAT1, STAT2, AKT, PRAS40, and ERK1/2 in the absence of IL2RB and IL2RG, whereas neither STAT5 nor JAK2 were activated. RNAi-mediated attenuation of IL15RA established its role in cell growth, apoptosis, and migration, whereas expression of the IL15 cytokine in IL15RA-expressing cells stimulated an autocrine signaling cascade that promoted cell proliferation and migration and blocked apoptosis. Notably, coexpression of IL15RA and IL15 was also sufficient to activate peripheral blood mononuclear cells upon coculture in a paracrine signaling manner. Overall, our findings offer a mechanistic explanation for the paradoxical association of some high-grade breast tumors with better survival outcomes, due to engagement of the immune stroma.

A Brief Overview of the WHO Classification of Breast Tumors, 4th Edition, Focusing on Issues and Updates from the 3rd Edition

The WHO Classification of Tumors of the Breast, 4th edition, is an update to the 3rd edition that was published in 2003, and covers all neoplastic and preneoplastic lesions of the breast. Changes to the 4th edition include new aspects and changes to the terminology that reflect our present-day knowledge of these lesions. Definitions for histopathological diagnosis are complemented by a description of clinical features, epidemiology, macroscopy, genetics, and prognostic and predictive features. In this review of the WHO classification, we have focused on invasive carcinomas, precursor lesions, and some benign epithelial proliferations.

Prognostic B-cell signatures using mRNA-seq in patients with subtype-specific breast and ovarian cancer

PURPOSE

Lymphocytic infiltration of tumors predicts improved survival in patients with breast cancer. Previous studies have suggested that this survival benefit is confined predominantly to the basal-like subtype. Immune infiltration in ovarian tumors is also associated with improved prognosis. Currently, it is unclear what aspects of the immune response mediate this improved outcome.

EXPERIMENTAL DESIGN

Using The Cancer Genome Atlas mRNA-seq data and a large microarray dataset, we evaluated adaptive immune gene expression by genomic subtype in breast and ovarian cancer. To investigate B-cells observed to be prognostic within specific subtypes, we developed methods to analyze B-cell population diversity and degree of somatic hypermutation (SHM) from B-cell receptor (BCR) sequences in mRNA-seq data.

RESULTS

Improved metastasis-free/progression-free survival was correlated with B-cell gene expression signatures, which were restricted mainly to the basal-like and HER2-enriched breast cancer subtypes and the immunoreactive ovarian cancer subtype. Consistent with a restricted epitope-driven response, a subset of basal-like and HER2-enriched breast tumors and immunoreactive ovarian tumors showed high expression of a low-diversity population of BCR gene segments. More BCR segments showed improved prognosis with increased expression in basal-like breast tumors and immunoreactive ovarian tumors compared with other subtypes. Basal-like and HER2-enriched tumors exhibited more BCR sequence variants in regions consistent with SHM.

CONCLUSION

Taken together, these data suggest the presence of a productive and potentially restricted antitumor B-cell response in basal-like breast and immunoreactive ovarian cancers. Immunomodulatory therapies that support B-cell responses may be a promising therapeutic approach to targeting these B-cell infiltrated tumors.

A role for T-lymphocytes in human breast cancer and in canine mammary tumors

Chronic inflammation in the tumor microenvironment has a prominent role in carcinogenesis and benefits the proliferation and survival of malignant cells, promoting angiogenesis and metastasis. Mammary tumors are frequently infiltrated by a heterogeneous population of immune cells where T-lymphocytes have a great importance. Interestingly, similar inflammatory cell infiltrates, cytokine and chemokine expression in humans and canine mammary tumors were recently described. However, in both species, despite all the scientific evidences that appoint for a significant role of T-lymphocytes, a definitive conclusion concerning the effectiveness of T-cell dependent immune mechanisms has not been achieved yet. In the present review, we describe similarities between human breast cancer and canine mammary tumors regarding tumor T-lymphocyte infiltration, such as relationship of TILs and mammary tumors malignancy, association of ratio CD4+/ CD8+ T-cells with low survival rates, promotion of tumor progression by Th2 cells actions, and association of great amounts of Treg cells with poor prognostic factors. This apparent parallelism together with the fact that dogs develop spontaneous tumors in the context of a natural immune system highlight the dog as a possible useful biological model for studies in human breast cancer immunology.

Predictive and prognostic factors in locally advanced breast cancer: effect of intratumoral FOXP3+ Tregs

This study aimed to investigate the prognostic and predictive effect of FOXP3+ Tregs together with clinicopathologic factors in locally advanced breast cancer (LABC) patients. The medical records of 101 LABC patients who received neoadjuvant chemotherapy (NAC) between 2005 and 2012 were evaluated retrospectively. The density of intratumoral FOXP3+ lymphocytes in paraffin-embedded tissues was assessed by immunohistochemical analyses in appropriate cases. The relationship with clinicopathologic features, prognosis and chemotherapy response was investigated. HR(-) and HER2(+) tumors tended to have higher pre-chemotherapy Tregs than HR(+) tumors, and significantly higher pathologic complete response (PCR) rates were observed in these patients. Treg decline after NAC was associated with better pathological response rates. Lower intratumoral infiltration of FOXP3+ Tregs after NAC (<3.4/HPF) was significantly associated with higher PCR rates for breast, and close to the significance limit for total (or both for breast and axillary) PCR rates (PCR for breast: 25 vs. 2.9 % for low vs. high Treg, p = 0.001; PCR for breast + axillary tissue: 13.9 vs. 0 %, p = 0.05). Despite better PCR rates, patients with high intratumoral Treg infiltrates (≥11.5/HPF) before chemotherapy had significantly shorter overall survival than patients with low Treg infiltrates (<11.5/HPF). Cox multivariate regression analyses demonstrated that the density of Treg infiltration before chemotherapy was the strongest predictor for survival. This study established the predictive and prognostic effect of intratumoral FOXP3+ Tregs in LABC patients. To predict clinical outcome, evaluation of FOXP3+ Tregs in tumoral tissues before and after NAC should be considered for these high-risk patients.

Inflammation and breast cancer

SUMMARY The relationship between breast cancer (BC) and inflammation remains unclear. Some risk factors, such as age, obesity and postmenopausal status, are also associated with increased levels of circulating proinflammatory cytokines and systemic inflammation. The role of T lymphocytes during BC development has been the subject of great debate, with improved survival reported when CD8+ and CD3+ T-lymphocytic infiltrates are present. Studies of B-lymphocytic infiltrates and prognosis have yielded conflicting results, but the extent of infiltration of tumor-associated macrophages is associated with reduced relapse-free and overall survival. There is consistent evidence that increased levels of proinflammatory factors, such as IL-6, IL-1β and TNF-α, and inflammatory chemokines, such as CCL2 and CCL5, are associated with increased risk of BC and poorer prognosis. However, it is not known whether this actually plays a role in tumor development. Substantially more work is needed to achieve a basis for effective anticancer therapy.

Immune aspects of the breast tumor microenvironment

The immune response in the tumor microenvironment is complex, consisting of cells from both the adaptive and innate immune systems. The phenotype and function of these cells are dictated by cytokines present in the microenvironment, as well as by the interactions of these cells with the tumor cells and each other. Technological advances have allowed investigators to better identify the specific immune cells present and immune-related gene signatures overexpressed in the tumor microenvironment. Increased knowledge of tumor immunology has allowed us to better understand how these cells and the developing tumor interact. Together, these advances have prompted the conduct of numerous studies investigating the prognostic and predictive significance of immune infiltrates.

Clinicopathologic characteristics at diagnosis and the survival of patients with medullary breast carcinoma in China: a comparison with infiltrating ductal carcinoma-not otherwise specified

BACKGROUND

Few studies have addressed the biological features of medullary breast carcinoma (MBC) in the context of clinical outcomes. We sought to compare the baseline demographics, standard pathologic factors and long-term clinical outcomes between MBC and infiltrating ductal carcinoma-not otherwise specified (IDC-NOS) using a large database.

METHODS

A total of 2,202 cases with pure IDC-NOS and 188 cases with typical MBC meeting the inclusion criteria were identified. The clinical and biological features, the overall survival (OS) and recurrence/metastasis-free survival (RFS) were compared for both groups.

RESULTS

There were a higher proportion of patients diagnosed prior to 40 years of age in the MBC group compared to the IDC-NOS group. MBC cases demonstrated less aggressive tumor features such as lower tumor stage, smaller tumor size and a lower proportion of nodal involvement than IDC-NOS; however, immunohistochemical staining revealed that MBC displayed the triple-negative phenotype more often than IDC-NOS cases (40.4% versus 26.2%; P <0.001). Although the clinical behavior of MBC was not commensurate with its pathologic features, women diagnosed with MBC had a lower frequency of recurrence/metastasis (P = 0.032) and death (P = 0.042) than those with IDC-NOS, and the 10-year OS and RFS were significantly higher for MBC (91% and 74%) compared to IDC-NOS (81% and 64%). Moreover, multivariate analysis revealed that TNM stage was a statistically significant factor for survival.

CONCLUSIONS

MBC in Chinese women demonstrated less aggressive behavior and better prognosis than IDC-NOS. This favorable outcome was maintained after 10 years.

Prognostic and predictive value of tumor-infiltrating lymphocytes in a phase III randomized adjuvant breast cancer trial in node-positive breast cancer comparing the addition of docetaxel to doxorubicin with doxorubicin-based chemotherapy: BIG 02-98

PURPOSE

Previous preclinical and clinical data suggest that the immune system influences prognosis and response to chemotherapy (CT); however, clinical relevance has yet to be established in breast cancer (BC). We hypothesized that increased lymphocytic infiltration would be associated with good prognosis and benefit from immunogenic CT-in this case, anthracycline-only CT-in selected BC subtypes.

PATIENTS AND METHODS

We investigated the relationship between quantity and location of lymphocytic infiltrate at diagnosis with clinical outcome in 2009 node-positive BC samples from the BIG 02-98 adjuvant phase III trial comparing anthracycline-only CT (doxorubicin followed by cyclophosphamide, methotrexate, and fluorouracil [CMF] or doxorubicin plus cyclophosphamide followed by CMF) versus CT combining doxorubicin and docetaxel (doxorubicin plus docetaxel followed by CMF or doxorubicin followed by docetaxel followed by CMF). Readings were independently performed by two pathologists. Disease-free survival (DFS), overall survival (OS), and interaction with type of CT associations were studied. Median follow-up was 8 years.

RESULTS

There was no significant prognostic association in the global nor estrogen receptor (ER) -positive/human epidermal growth factor receptor 2 (HER2) -negative population. However, each 10% increase in intratumoral and stromal lymphocytic infiltrations was associated with 17% and 15% reduced risk of relapse (adjusted P = .1 and P = .025), respectively, and 27% and 17% reduced risk of death in ER-negative/HER2-negative BC regardless of CT type (adjusted P = .035 and P = .023), respectively. In HER2-positive BC, there was a significant interaction between increasing stromal lymphocytic infiltration (10% increments) and benefit with anthracycline-only CT (DFS, interaction P = .042; OS, P = .018).

CONCLUSION

In node-positive, ER-negative/HER2-negative BC, increasing lymphocytic infiltration was associated with excellent prognosis. Further validation of the clinical utility of tumor-infiltrating lymphocytes in this context is warranted. Our data also support the evaluation of immunotherapeutic approaches in selected BC subtypes.

Prognosis of medullary breast cancer: analysis of 13 International Breast Cancer Study Group (IBCSG) trials

BACKGROUND

To evaluate whether medullary breast cancer has a better prognosis compared with invasive ductal tumors.

METHODS

Among 12,409 patients, 127 were recorded as invasive medullary tumors and 8096 invasive ductal tumors. Medullary and ductal invasive tumors were compared with regard to stage, age at diagnosis, grade, hormone receptor status, peritumoral vascular invasion, and local and systemic treatment. Pattern of relapse, distant recurrence-free interval (DRFI), and overall survival (OS) were determined for both histological groups. Two cohorts were investigated: a full cohort including the pathologist-determined medullary histology without regard to any other tumor features and a cohort restricted to patients with ER-negative grade 3 tumors.

RESULTS

Fourteen-year DRFI and OS percents for medullary tumors (n = 127) and invasive ductal tumors (n = 8096) of the full cohort were 76% and 64% [hazard ratio (HR) 0.52, P = 0.0005] and 66% and 57% (HR = 0.75, P = 0.03), respectively. For the restricted cohort, 14-year DRFI and OS percents for the medullary (n = 47) and invasive ductal tumors (n = 1407) were 89% and 63% (HR 0.24, P = 0.002) and 74% and 54% (HR = 0.55, P = 0.01), respectively. Competing risk analysis for DRFI favored medullary tumors (HR medullary/ductal = 0.32; 95% confidence interval = 0.13-0.78, P = 0.01).

CONCLUSION

Medullary tumors have a favorable prognosis compared with invasive ductal tumors.

Triple-negative breast cancer is associated with EGFR, CK5/6 and c-KIT expression in Malaysian women

BACKGROUND

Triple-negative breast cancer (TNBC) is a heterogeneous subgroup of breast cancer characterized by the lack of estrogen receptor (ER), progesterone receptor (PR) and the human epidermal growth factor receptor 2 (HER2) expressions. This subgroup of refractory disease tends to have aggressive clinical behavior, high frequency of metastasis and lack of response to current hormonal or targeted therapies. Despite numerous studies reporting the clinicopathological features of TNBC and its association with the basal-like phenotype in the Western population, only limited data are available in the Asian population. Therefore, the aim of this study was to investigate the clinicopathological characteristics of TNBC and its association with epidermal growth factor receptor (EGFR), cytokeratin 5/6 (CK5/6) and mast/stem cell growth factor receptor (c-KIT or CD117) expression in Malaysian women.

METHODS

A total of 340 patients diagnosed with primary breast cancer between 2002 and 2006 in Malaysia were reviewed and analyzed.

RESULTS

The incidence of TNBC was 12.4% (42/340). Bivariate analysis revealed that TNBC was strongly associated with a younger age, higher grade tumor and p53 expression. Further immunohistochemical analysis suggested that TNBC in Malaysian women was strongly associated with EGFR, CK5/6 and c-KIT expression with high a Ki-67 proliferation index.

CONCLUSION

In conclusion, our study confirms the association of TNBC with basal-like marker expression (EGFR, CK5/6 and c-KIT) in Malaysian women, consistent with studies in other populations.

The role of the tumour inflammatory cell infiltrate in predicting recurrence and survival in patients with primary operable breast cancer

Although the first studies highlighting the importance of the tumour inflammatory cell infiltrate were reported more than 80 years ago, the prognostic value of this response in breast cancer is still controversial. With the realisation of the importance of the inflammatory response in determining tumour progression there has been renewed interest in establishing the relationship between the type, density and location of inflammatory cell infiltrate and survival in patients with primary operable breast cancer. The aim was to undertake a systematic review of the literature examining the evidence for the role of the tumour inflammatory cell infiltrate in predicting recurrence and survival in patients with primary operable breast cancer. A systematic review of published papers up to September 2011 was undertaken according to a pre-defined protocol (Fig. 1). A total of 66 independent studies (34,086 patients) were identified. It can be concluded from the review that despite the large number of studies and considerable effort over an extended period, the relationship between different aspects of tumour inflammatory cell infiltrate and outcome in primary operable breast cancer remains unclear. This is in large part due to the absence of methodological validation, underpowered studies (small sample size and sample subtype heterogeneity, insufficient follow-up) and the absence of validation datasets. Therefore, although there are tantalising examples of the potential of the tumour inflammatory cell infiltrate to improve risk stratification patients with operable breast cancer (personalised care), this has not yet been realised. Future studies with standardised methodology, large and homogenous groups, sufficient follow-up and validation datasets should be undertaken to unlock the potential of the tumour inflammatory infiltrate to predict outcome in patients with primary operable breast cancer.

The clinical significance of tumor infiltrating lymphoctyes in breast cancer: does subtype matter?

Tumor infiltrating lymphocytes (TILs) are commonly detected in breast tumors but their bearing on disease outcome is uncertain. The importance of TILs appears to be subtype-specific and varies depending on the histologic characteristics of the tumor. As our understanding of tumorigenesis is increasing the relevance of immunobiology will become apparent.

Differential pattern and prognostic significance of CD4+, FOXP3+ and IL-17+ tumor infiltrating lymphocytes in ductal and lobular breast cancers

Background

Clinical relevance of tumor infiltrating lymphocytes (TILs) in breast cancer is controversial. Here, we used a tumor microarray including a large series of ductal and lobular breast cancers with long term follow up data, to analyze clinical impact of TIL expressing specific phenotypes and distribution of TILs within different tumor compartments and in different histological subtypes.

Methods

A tissue microarray (TMA) including 894 ductal and 164 lobular breast cancers was stained with antibodies recognizing CD4, FOXP3, and IL-17 by standard immunohistochemical techniques. Lymphocyte counts were correlated with clinico-pathological parameters and survival.

Results

CD4⁺ lymphocytes were more prevalent than FOXP3⁺ TILs whereas IL-17⁺ TILs were rare. Increased numbers of total CD4⁺ and FOXP3⁺ TIL were observed in ductal, as compared with lobular carcinomas. High grade (G3) and estrogen receptor (ER) negative ductal carcinomas displayed significantly (p < 0.001) higher CD4⁺ and FOXP3⁺ lymphocyte infiltration while her2/neu over-expression in ductal carcinomas was significantly (p < 0.001) associated with higher FOXP3⁺ TIL counts. In contrast, lymphocyte infiltration was not linked to any clinico-pathological parameters in lobular cancers. In univariate but not in multivariate analysis CD4⁺ infiltration was associated with significantly shorter survival in patients bearing ductal, but not lobular cancers. However, a FOXP3⁺/CD4⁺ ratio > 1 was associated with improved overall survival even in multivariate analysis (p = 0.033).

Conclusions

Ductal and lobular breast cancers appear to be infiltrated by different lymphocyte subpopulations. In ductal cancers increased CD4⁺ and FOXP3⁺ TIL numbers are associated with more aggressive tumor features. In survival analysis, absolute numbers of TILs do not represent major prognostic indicators in ductal and lobular breast cancer. Remarkably however, a ratio > 1 of total FOXP3⁺/CD4⁺ TILs in ductal carcinoma appears to represent an independent favorable prognostic factor.

CD8+ lymphocyte infiltration is an independent favorable prognostic indicator in basal-like breast cancer

Introduction

Tumor infiltrating lymphocytes may indicate an immune response to cancer development, but their significance remains controversial in breast cancer. We conducted this study to assess CD8+ (cytotoxic T) lymphocyte infiltration in a large cohort of invasive early stage breast cancers, and to evaluate its prognostic effect in different breast cancer intrinsic subtypes.

Methods

Immunohistochemistry for CD8 staining was performed on tissue microarrays from 3992 breast cancer patients. CD8+ tumor infiltrating lymphocytes were counted as intratumoral when in direct contact with tumor cells, and as stromal in adjacent locations. Kaplan-Meier functions and Cox proportional hazards regression models were applied to examine the associations between tumor infiltrating lymphocytes and breast cancer specific survival.

Results

Among 3403 cases for which immunohistochemical results were obtained, CD8+ tumor infiltrating lymphocytes were identified in an intratumoral pattern in 32% and stromal pattern in 61% of the cases. In the whole cohort, the presence of intratumoral tumor-infiltrating lymphocytes was significantly correlated with young age, high grade, estrogen receptor negativity, human epidermal growth factor receptor-2 positivity and core basal intrinsic subtype, and was associated with superior breast cancer specific survival. Multivariate analysis indicated that the favorable prognostic effect of CD8+ tumor infiltrating lymphocytes was significant only in the core basal intrinsic subgroup (Hazard ratio, HR = 0.35, 95% CI = 0.23-0.54). No association with improved survival was present in those triple negative breast cancers that lack expression of basal markers (HR = 0.99, 95% CI = 0.48-2.04) nor in the other intrinsic subtypes.

Conclusions

CD8+ tumor infiltrating lymphocytes are an independent prognostic factor associated with better patient survival in basal-like breast cancer, but not in non-basal triple negative breast cancers nor in other intrinsic molecular subtypes.

In breast cancer, a high ratio of tumour-infiltrating intraepithelial CD8+ to FoxP3+ cells is characteristic for the medullary subtype

AIMS

Medullary breast cancer (MBC) is a biologically distinct subtype of breast cancer characterized by prominent lymphocytic infiltrates and a favourable clinical outcome. Tumour-infiltrating CD8+ effector T cells may contribute to the good prognosis of this type of cancer; however, certain subtypes of lymphocyte, such as FoxP3+ regulatory T cells (Tregs), can also suppress antitumour immunity.

METHODS AND RESULTS

We determined tumour infiltration by FoxP3+, CCL22+ and CD8+ cells in paraffin-embedded sections of MBC, and, as a reference, in samples of grade 3 ductal, lobular and mucinous breast cancer. All analysed MBCs were strongly infiltrated by FoxP3+ cells, whereas only weak infiltrates were detected in ductal or lobular breast cancer. This finding was unexpected, given the good prognosis of MBC. Strikingly, the number of CD8+ T cells exceeded the number of FoxP3+ cells in MBC (ratio of CD8+ to FoxP3+ cells of 2.6), whereas equal amounts of both cell types were found in ductal breast cancer (ratio of CD8+ to FoxP3+ cells of 1.1). In both types of breast cancer, we also detected cells expressing the Treg-attracting chemokine CCL22.

CONCLUSIONS

In breast cancer, a predominance of tumour-infiltrating CD8+ over FoxP3+ cells was observed in MBC. Thus, the ratio of CD8+ to FoxP3+ cells rather than the absolute number of intratumoral FoxP3+ cells may be predictive for the clinical outcome of cancer.

High expression of indoleamine 2,3-dioxygenase in the tumour is associated with medullary features and favourable outcome in basal-like breast carcinoma

Medullary breast cancer (MBC) is a basal-like breast carcinoma (BLBC) with a favourable outcome, whereas nonmedullary BLBC has a poor prognosis. Tumour infiltrating lymphocytes (TILs) are present in both MBC and BLBC. We hypothesized that the immunosuppressive enzyme indoleamine 2,3-dioxygenase (IDO) could modulate the TILs effects among these tumours and explain their different outcomes. The amount of TILs and IDO expression were analysed using immunohistochemistry (IHC) in 155 BC cases including MBC (n = 17), atypical MBC (n = 13) and non-MBC (n = 125). Messenger RNA expression of the INDO gene, which encodes IDO, was measured in 262 cases from our institution. INDO mRNA expression and histoclinical data of 1,487 BC cases were collected from public databases. IDO immunostaining was present in both neoplastic and stromal cells in 100% of MBC and was associated with histological medullary features among non-MBC cases. There was a significant correlation between IDO positivity and TIL amounts. In our series including mostly grade-3 BC, IDO immunostaining was the most significant marker (p = 0.02) associated with better survival in multivariate analysis. Among our 262 analysed BC cases, INDO mRNA showed significant overexpression in BLBC as compared to luminal A tumours, and in MBC as compared to basal-like non-MBC. In the pooled series of 1,749 BC cases, INDO mRNA was overexpressed in BLBC and was the most significant predictor of better survival in this subtype using multivariate analysis (p = 0.0024). In conclusion, high IDO expression is associated with morphological medullary features and has an independent favourable prognostic value in BLBC.

Influence of uncommon histology on breast conservation therapy for breast cancer-biology dictates technique?

INTRODUCTION

Although trends and variations in the use of breast conservation therapy (BCT) for ductal carcinoma have been studied, little is known about uncommon breast cancer histologies.

METHODS

The Surveillance, Epidemiology and End Results (SEER) database was used to identify 338,682 patients with T1 or T2 (≤5 cm) ductal, lobular, tubular, mucinous, medullary, or papillary carcinoma of the breast from 1998 to 2008. Multivariate logistic regression analysis was used to identify predictors of BCT.

RESULTS

The majority of patients underwent BCT (60%). The rate of BCT remained relatively constant from 1998 to 2008 overall but varied from 50% for lobular to 79% for tubular. The highest rate of mastectomy was seen in lobular (49%). Nodal positivity following surgical staging was lowest for tubular (6%) and mucinous (8%). Adjuvant radiation was given to 72% overall and was lowest for papillary (58%). Predictors of BCT included tubular (OR 1.8, 95% CI 1.7-1.9) and medullary (OR 2.0, 95% CI 1.8-2.2) subtypes (vs. ductal).

CONCLUSIONS

Patients with uncommon breast cancer histologies show wide variation in the application of BCT depending on the primary tumor. This suggests that an individualized approach in the use of BCT depending on histology should be used.

Triple negative breast cancer: proposals for a pragmatic definition and implications for patient management and trial design

In trials in triple negative breast cancer (TNBC), oestrogen and progesterone receptor negativity should be defined as < 1% positive cells. Negativity is a ratio of <2 between Her2 gene copy number and centromere of chromosome 17 or a copy number of 4 or less. In routine practice, immunohistochemistry is acceptable given stringent quality assurance. Triple negativity emerging after neoadjuvant treatment differs from primary TN and such patients should not enter TNBC trials. Patients relapsing with TN metastases should be eligible even if their primary was positive. Rare TN subtypes such as apocrine, adenoid-cystic and low-grade metaplastic tumours should be excluded. TN and basal-like (BL) signatures overlap but are not equivalent. Since the significance of basal cytokeratin or EGFR overexpression is not known and we lack validated assays, these features should not be used to subclassify TN tumours. Tissue collection in trials is mandatory so the effect on outcome of different tumour phenotypes and BRCA mutation can be explored. No prospective studies have established that TN tumours have particular sensitivity or resistance to any specific chemotherapy agent or radiation. TNBC patients should be treated according to tumour and clinical characteristics.