Tumor-infiltrating lymphocytes and ductal carcinoma in situ of the breast: friends or foes?

Predictive and Prognostic Relevance of Tumor-Infiltrating Immune Cells: Tailoring Personalized Treatments against Different Cancer Types

TIICs are critical components of the TME and are used to estimate prognostic and treatment responses in many malignancies. TIICs in the tumor microenvironment are assessed and quantified by categorizing immune cells into three subtypes: CD66b+ tumor-associated neutrophils (TANs), FoxP3+ regulatory T cells (Tregs), and CD163+ tumor-associated macrophages (TAMs). In addition, many cancers have tumor-infiltrating M1 and M2 macrophages, neutrophils (Neu), CD4+ T cells (T-helper), CD8+ T cells (T-cytotoxic), eosinophils, and mast cells. A variety of clinical treatments have linked tumor immune cell infiltration (ICI) to immunotherapy receptivity and prognosis. To improve the therapeutic effectiveness of immune-modulating drugs in a wider cancer patient population, immune cells and their interactions in the TME must be better understood. This study examines the clinicopathological effects of TIICs in overcoming tumor-mediated immunosuppression to boost antitumor immune responses and improve cancer prognosis. We successfully analyzed the predictive and prognostic usefulness of TIICs alongside TMB and ICI scores to identify cancer's varied immune landscapes. Traditionally, immune cell infiltration was quantified using flow cytometry, immunohistochemistry, gene set enrichment analysis (GSEA), CIBERSORT, ESTIMATE, and other platforms that use integrated immune gene sets from previously published studies. We have also thoroughly examined traditional limitations and newly created unsupervised clustering and deconvolution techniques (SpatialVizScore and ProTICS). These methods predict patient outcomes and treatment responses better. These models may also identify individuals who may benefit more from adjuvant or neoadjuvant treatment. Overall, we think that the significant contribution of TIICs in cancer will greatly benefit postoperative follow-up, therapy, interventions, and informed choices on customized cancer medicines.

signifinder enables the identification of tumor cell states and cancer expression signatures in bulk, single-cell and spatial transcriptomic data

Over the last decade, many studies and some clinical trials have proposed gene expression signatures as a valuable tool for understanding cancer mechanisms, defining subtypes, monitoring patient prognosis, and therapy efficacy. However, technical and biological concerns about reproducibility have been raised. Technical reproducibility is a major concern: we currently lack a computational implementation of the proposed signatures, which would provide detailed signature definition and assure reproducibility, dissemination, and usability of the classifier. Another concern regards intratumor heterogeneity, which has never been addressed when studying these types of biomarkers using bulk transcriptomics. With the aim of providing a tool able to improve the reproducibility and usability of gene expression signatures, we propose signifinder, an R package that provides the infrastructure to collect, implement, and compare expression-based signatures from cancer literature. The included signatures cover a wide range of biological processes from metabolism and programmed cell death, to morphological changes, such as quantification of epithelial or mesenchymal-like status. Collected signatures can score tumor cell characteristics, such as the predicted response to therapy or the survival association, and can quantify microenvironmental information, including hypoxia and immune response activity. signifinder has been used to characterize tumor samples and to investigate intra-tumor heterogeneity, extending its application to single-cell and spatial transcriptomic data. Through these higher-resolution technologies, it has become increasingly apparent that the single-sample score assessment obtained by transcriptional signatures is conditioned by the phenotypic and genetic intratumor heterogeneity of tumor masses. Since the characteristics of the most abundant cell type or clone might not necessarily predict the properties of mixed populations, signature prediction efficacy is lowered, thus impeding effective clinical diagnostics. Through signifinder, we offer general principles for interpreting and comparing transcriptional signatures, as well as suggestions for additional signatures that would allow for more complete and robust data inferences. We consider signifinder a useful tool to pave the way for reproducibility and comparison of transcriptional signatures in oncology.

The role of IL-35 and IL-37 in breast cancer - potential therapeutic targets for precision medicine

Breast cancer is still a major concern due to its relatively poor prognosis in women, although there are many approaches being developed for the management of breast cancer. Extensive studies demonstrate that the development of breast cancer is determined by pro versus anti tumorigenesis factors, which are closely related to host immunity. IL-35 and IL-37, anti-inflammatory cytokines, play an important role in the maintenance of immune homeostasis. The current review focuses on the correlation between clinical presentations and the expression of IL-35 and IL-37, as well as the potential underlying mechanism during the development of breast cancer in vitro and in vivo. IL-35 is inversely correlated the differentiation and prognosis in breast cancer patients; whereas IL-37 shows dual roles during the development of breast cancer, and may be breast cancer stage dependent. Such information might be useful for both basic scientists and medical practitioners in the management of breast cancer patients.

Tumor Infiltrating Lymphocytes in Multi-National Cohorts of Ductal Carcinoma In Situ (DCIS) of Breast

Tumor-infiltrating lymphocytes (TILs) are prognostic in invasive breast cancer. However, their prognostic significance in ductal carcinoma in situ (DCIS) has been controversial. To investigate the prognostic role of TILs in DCIS outcome, we used different scoring methods for TILs in multi-national cohorts from Asian and European women. Self-described race was genetically confirmed using QC Infinium array combined with radmixture software. Stromal TILs, touching TILs, circumferential TILs, and hotspots were quantified on H&E-stained slides and correlated with the development of second breast cancer events (BCE) and other clinico-pathological variables. In univariate survival analysis, age older than 50 years, hormone receptor positivity and the presence of circumferential TILs were weakly associated with the absence of BCE at the 5-year follow-up in all cohorts (p < 0.03; p < 0.02; and p < 0.02, respectively, adjusted p = 0.11). In the multivariable analysis, circumferential TILs were an independent predictor of a better outcome (Wald test p = 0.01), whereas younger age was associated with BCE. Asian patients were younger with larger, higher grade, HR negative DCIS lesions, and higher TIL variables. The spatial arrangement of TILs may serve as a better prognostic indicator in DCIS cases than stromal TILs alone and may be added in guidelines for TILs evaluation in DCIS.

Macrophage density is an adverse prognosticator for ipsilateral recurrence in ductal carcinoma in situ

INTRODUCTION

There is evidence that supports the association of dense tumor infiltrating lymphocyte (TILs) with an increased risk of ipsilateral recurrence in ductal carcinoma in situ (DCIS). However, the association of cellular composition of DCIS immune microenvironment with the histopathologic parameters and outcome is not well understood.

METHODS

We queried our institutional database for patients with pure DCIS diagnosed between 2010 and 2019. Immunohistochemical studies for CD8, CD4, CD68, CD163, and FOXP3 were performed and evaluated in the DCIS microenvironment using tissue microarrays. Statistical methods included Fisher's exact test for categorical variables and the two-sample t-test or the Wilcoxon Rank-Sum test for continuous variables.

RESULTS

The analytic sample included 67 patients. Median age was 62 years (range = 53 to 66) and median follow up was 6.7 years (range = 5.3 to 7.8). Thirteen patients had ipsilateral recurrence. Of all the clinicopathologic variables, only the DCIS size and TIL density were significantly associated with recurrence (p = 0.023 and 0.006, respectively). After adjusting for age and TIL density, only high CD68 (>50) and high CD68/CD163 ratio (>0.46) correlated with ipsilateral recurrence (p = 0.026 and 0.013, respectively) and shorter time to recurrence [hazard ratio 4.87 (95% CI: 1.24-19, p = 0.023) and 10.32 (95% CI: 1.34-80, p = 0.025), respectively].

CONCLUSIONS

In addition to DCIS size and TIL density, high CD68+ tumor-associated macrophages predict ipsilateral recurrence in DCIS. High CD68+ macrophage density and CD68/CD163 ratio also predict a shorter time to recurrence.

Relationship between Th17 immune response and cancer

Cancer is the second leading cause of death worldwide and epidemiological projections predict growing cancer mortality rates in the next decades. Cancer has a close relationship with the immune system and, although Th17 cells are known to play roles in the immune response against microorganisms and in autoimmunity, studies have emphasized their roles in cancer pathogenesis. The Th17 immune response profile is involved in several types of cancer including urogenital, respiratory, gastrointestinal, and skin cancers. This type of immune response exerts pro and antitumor functions through several mechanisms, depending on the context of each tumor, including the protumor angiogenesis and exhaustion of T cells and the antitumor recruitment of T cells and neutrophils to the tumor microenvironment. Among other factors, the paradoxical behavior of Th17 cells in this setting has been attributed to its plasticity potential, which makes possible their conversion into other types of T cells such as Th17/Treg and Th17/Th1 cells. Interleukin (IL)-17 stands out among Th17-related cytokines since it modulates pathways and interacts with other cell profiles in the tumor microenvironment, which allow Th17 cells to prevail in tumors. Moreover, the IL-17 is able to mediate pro and antitumor processes that influence the development and progression of various cancers, being associated with variable clinical outcomes. The understanding of the relationship between the Th17 immune response and cancer as well as the singularities of carcinogenic processes in each type of tumor is crucial for the identification of new therapeutic targets.

Transcriptomic Properties of HER2+ Ductal Carcinoma In Situ of the Breast Associate with Absence of Immune Cells

The identification of transcriptomic alterations of HER2+ ductal carcinoma in situ (DCIS) that are associated with the density of tumor-infiltrating lymphocytes (TILs) could contribute to optimizing choices regarding the potential benefit of immune therapy. We compared the gene expression profile of TIL-poor HER2+ DCIS to that of TIL-rich HER2+ DCIS. Tumor cells from 11 TIL-rich and 12 TIL-poor DCIS cases were micro-dissected for RNA isolation. The Ion AmpliSeq Transcriptome Human Gene Expression Kit was used for RNA sequencing. After normalization, a Mann-Whitney rank sum test was used to analyze differentially expressed genes between TIL-poor and TIL-rich HER2+ DCIS. Whole tissue sections were immunostained for validation of protein expression. We identified a 29-gene expression profile that differentiated TIL-rich from TIL-poor HER2+ DCIS. These genes included CCND3, DUSP10 and RAP1GAP, which were previously described in breast cancer and cancer immunity and were more highly expressed in TIL-rich DCIS. Using immunohistochemistry, we found lower protein expression in TIL-rich DCIS. This suggests regulation of protein expression at the posttranslational level. We identified a gene expression profile of HER2+ DCIS cells that was associated with the density of TILs. This classifier may guide towards more rationalized choices regarding immune-mediated therapy in HER2+ DCIS, such as targeted vaccine therapy.

Modulation of the immune microenvironment of high-risk ductal carcinoma in situ by intralesional pembrolizumab injection

Ductal carcinoma in situ (DCIS) is a risk factor for the subsequent development of invasive breast cancer. High-risk features include age <45 years, size >5 cm, high-grade, palpable mass, hormone receptor negativity, and HER2 positivity. We have previously shown that immune infiltrates are positively associated with these high-risk features, suggesting that manipulating the immune microenvironment in high-risk DCIS could potentially alter disease progression. Patients with high-risk DCIS were enrolled in this 3 × 3 phase 1 dose-escalation pilot study of 2, 4, and 8 mg intralesional injections of the PD-1 immune checkpoint inhibitor, pembrolizumab. Study participants received two intralesional injections, three weeks apart, prior to surgery. Tissue from pre-treatment biopsies and post-treatment surgical resections was analyzed using multiplex immunofluorescence (mIF) staining for various immune cell populations. The intralesional injections were easily administered and well-tolerated. mIF analyses demonstrated significant increases in total T cell and CD8+ T cell percentages in most patients after receiving pembrolizumab, even at the 2 mg dose. T cell expansion was confined primarily to the stroma rather than within DCIS-containing ducts. Neither cleaved caspase 3 (CC3) staining, a marker for apoptosis, nor DCIS volume (as measured by MRI) changed significantly following treatment. Intralesional injection of pembrolizumab is safe and feasible in patients with DCIS. Nearly all patients experienced robust total and CD8+ T cell responses. However, we did not observe evidence of cell death or tumor volume decrease by MRI, suggesting that additional strategies may be needed to elicit stronger anti-tumor immunity.

Prognostic and predictive significance of tumor infiltrating lymphocytes for ductal carcinoma in situ

This study aims to identify the density of TILs in ductal carcinoma in situ (DCIS) in terms of prognostic significance with recurrence and the benefit of whole breast irradiation (WBI). The clinicopathological data of DCIS patients from Jan 2009 to Dec 2016 who received breast-conserving surgery (BCS) were retrospectively reviewed. Cox regression analysis was used to confirm independent prognostic factors of ipsilateral breast tumor recurrence (IBTR). Kaplan–Meier method was utilized to analyze IBTR and values of WBI. Touching-tumor-infiltrating lymphocytes (TILs) were defined by TILs touching or within one lymphocyte cell thickness from the malignant ducts’ basement membrane. In total, 129 patients were enrolled in this analysis with 98 patients who received WBI. After a median follow-up of 53.0 months, there were 16 IBTR events with five invasive IBTRs. Univariate and multivariate analyses showed that touching-TILs >5 were an independent prognostic factor for higher IBTR (HR = 6.17, 95%CI 1.95–19.56, p < .01). The whole cohort was classified into two subgroups: dense group (>5 touching-TILs per duct) and sparse group (≤5 touching-TILs per duct). Dense touching-TILs were associated with unfavorable biologic characteristics. The 5-y rate of IBTR between dense and sparse group was 29.0% versus 4.5% (p < .01). For the sparse group, WBI significantly reduced the rate of 5-y-IBTR risk from 13.2% to 1.7% (p = .02), but there was no benefit of WBI in the dense group. Touching-TILs density was heterogeneous in patients with DCIS. Sparse touching-TILs were associated with better prognosis and benefit from WBI. Dense touching-TILs not only were associated with a higher risk of IBTR but also lack of benefit from WBI.

Higher densities of tumour-infiltrating lymphocytes and CD4+ T cells predict recurrence and progression of ductal carcinoma in situ of the breast

AIMS

Host immunity influences cancer progression and therapeutic response. We investigated the potential of tumour-infiltrating lymphocytes (TILs) around ductal carcinoma in situ (DCIS) in predicting recurrence and progression.

METHODS AND RESULTS

CD4, CD8, programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) expression in DCIS from 198 patients was determined by immunohistochemistry. We correlated disease-free survival (DFS), clinicopathological parameters and biomarker expression with TIL density and CD4/CD8 ratio. High TIL density was associated with high nuclear grade (P < 0.001), DCIS PD-L1 expression (P = 0.008), TIL PD-L1 expression (P < 0.001), oestrogen (ER) negativity (P < 0.001), progesterone (PR) negativity (P < 0.001), human epidermal growth factor receptor 2 (HER2) positivity (P = 0.002) and triple negativity (P = 0.001). TIL PD-L1 expression was associated with triple-negative DCIS (P = 0.028). TIL density was associated with molecular subtypes (P < 0.001). High CD4⁺ T cell density was associated with high nuclear grade (P = 0.001), microinvasion (P = 0.037), ER negativity (P < 0.001), PR negativity (P = 0.001), HER2 positivity (P = 0.004), triple negativity (P = 0.023) and PD-L1 expression in TILs (P < 0.011). High CD4/CD8 ratio was associated with PD-L1 expression in DCIS (P = 0.035) and TILs (P < 0.001). DCIS with higher TIL density disclosed worse DFS (P = 0.012) and was affirmed with multivariate analysis [95% confidence interval (CI) = 1.109-2.554, hazard ratio (HR) = 1.683, P = 0.014]. Poorer DFS for ipsilateral invasive recurrence was found for DCIS with higher CD4⁺ T cell density (P = 0.006) or CD4/CD8 ratio (P = 0.02), confirmed by multivariate analysis for the former (95% CI = 1.369-10.196, HR = 3.736, P = 0.01) and latter (95% CI = 1.311-7.935, HR = 3.225, P = 0.011).

CONCLUSION

DCIS with higher TIL density was associated with poorer prognostic parameters and predicted recurrence, while both CD4⁺ T cell density and CD4/CD8 ratio were associated with both recurrence and ipsilateral invasive recurrence.

NR3C2-Related Transcriptome Profile and Clinical Outcome in Invasive Breast Carcinoma

Background

Increasing evidence has indicated that the nuclear receptor subfamily 3 group C member 2 (NR3C2) may be associated with tumorigenesis and patient prognosis for certain types of tumors. However, the clinical significance of NR3C2 is unclear in invasive breast carcinoma (BRCA).

Methods

We used bioinformatics to broadly investigate and obtain a deeper understanding of the prognostic significance between NR3C2 and BRCA. RNA-sequencing data and clinical information of patients with BRCA from the Cancer Genome Atlas database were collected for subsequent analysis. The diagnostic efficacy of NR3C2 was evaluated by calculating the receiver operating characteristic curve. The prognostic value of NR3C2 was evaluated by Kaplan-Meier analysis and Cox regression analysis for patients with BRCA. Moreover, the OSbrca database was used to validate NR3C2 as a prognostic biomarker for BRCA. Gene set enrichment analysis (GSEA) and tumor immune infiltration analysis were conducted to explore the molecular mechanism of NR3C2 in BRCA.

Results

The expression level of NR3C2 in BRCA tissues decreased compared to that in normal breast tissues (P < 0.001). NR3C2 presented good diagnostic efficacy (AUC = 0.908). Moreover, the expression of NR3C2 was verified using the Oncomine database. High expression of NR3C2 was statistically associated with prolonged overall survival (HR = 0.65, 95% CI: 0.47-0.91, and P = 0.012), progression-free interval (HR = 0.68, 95% CI: 0.49-0.95, and P = 0.024), and disease-specific survival (HR = 0.57, 95% CI: 0.36-0.89, and P = 0.015) for patients with BRCA. Besides, the prognostic value of NR3C2 was verified by the OSbrca database. GSEA results suggested that enriched pathways included neuroactive ligand-receptor interaction, focal adhesion, and ECM-receptor interaction. NR3C2 expression was moderately correlated with mast cells and some T cell subsets in BRCA.

Conclusion

NR3C2 is a potential prognostic biomarker that could help clinicians develop more appropriate treatment plans for individual patients with BRCA.

Tumour-infiltrating lymphocytes in ductal carcinoma in situ (DCIS)-assessment with three different methodologies and correlation with Oncotype DX DCIS Score

AIMS

Tumour-infiltrating lymphocytes (TILs) are prognostic in invasive breast cancer; however, their prognostic significance in ductal carcinoma in situ (DCIS) has not been established. The Oncotype DX (ODX) Breast DCIS Score test is a genomic assay used to predict the local recurrence risk. The aims of this study were to quantify TILs in DCIS by the use of three methodologies, and correlate them with the ODX DCIS Score.

METHODS AND RESULTS

We studied 97 DCIS cases, all with an ODX DCIS Score. Cases with a low ODX DCIS Score were considered as one group, and those with an intermediate/high ODX Score were considered together. TILs were quantified on haematoxylin and eosin-stained slides. The methodologies used to quantify TILS included assessment of stromal TILs, assessment of touching TILs, and assessment of circumferential TILS. In cases with >5% stromal TILS, the percentage of stromal TILS was considered to be high. In cases with a mean number of more than five touching TILs per DCIS duct, TILs were considered to be present. The ODX DCIS Score was intermediate/high in 27 (28%) cases and low in 70 (72%) cases. There were >5% stromal TILs in 33 (34%) cases, and more than five touching TILs per DCIS duct in 15 (15%) cases; circumferential TILs were present in nine (9%) cases. In univariate analysis, a low ODX DCIS Score showed significant associations with absent touching TILS (P = 0.027), stromal TILs < 5% (P = 0.031), and absent circumferential TILs (P = 0.002). In logistic regression analysis adjusted for necrosis and nuclear grade, touching TILs and circumferential TILs showed significant associations with the ODX DCIS Score, whereas stromal TILs did not.

CONCLUSIONS

Our results suggest that both the presence of TILs and the spatial arrangement of TILs or close proximity of TILs to DCIS, and TILs touching or encircling DCIS, may be predictive of recurrence.

Interobserver Variability in Ductal Carcinoma In Situ of the Breast

OBJECTIVES

Since most patients with ductal carcinoma in situ (DCIS) of the breast are treated upon diagnosis, evidence on its natural progression to invasive carcinoma is limited. It is estimated that around half of the screen-detected DCIS lesions would have remained indolent if they had never been detected. Many patients with DCIS are therefore probably overtreated. Four ongoing randomized noninferiority trials explore active surveillance as a treatment option. Eligibility for these trials is mainly based on histopathologic features. Hence, the call for reproducible histopathologic assessment has never sounded louder.

METHODS

Here, the available classification systems for DCIS are discussed in depth.

RESULTS

This comprehensive review illustrates that histopathologic evaluation of DCIS is characterized by significant interobserver variability. Future digitalization of pathology, combined with development of deep learning algorithms or so-called artificial intelligence, may be an innovative solution to tackle this problem. However, implementation of digital pathology is not within reach for each laboratory worldwide. An alternative classification system could reduce the disagreement among histopathologists who use "conventional" light microscopy: the introduction of dichotomous histopathologic assessment is likely to increase interobserver concordance.

CONCLUSIONS

Reproducible histopathologic assessment is a prerequisite for robust risk stratification and adequate clinical decision-making. Two-tier histopathologic assessment might enhance the quality of care.

Immune response and stromal changes in ductal carcinoma in situ of the breast are subtype dependent

Ductal carcinoma in situ (DCIS) associated stromal changes and influx of immune cells might be mediators of progression to invasive breast cancer. We studied the interaction between DCIS-associated stromal changes, and immune cell distribution and composition in a well-characterized patient cohort. We included 472 patients with DCIS. The presence of stromal changes, signs of regression, and DCIS-associated immune cell position were determined on hematoxylin and eosin-stained slides. Immune cell composition was characterized by immunohistochemistry (CD4, CD8, CD20, CD68, and FOXP3). The number of intraductal immune cells was quantified per mm². The interaction between stromal changes, signs of DCIS regression, immune cell composition and location was explored. Stromal changes and signs of DCIS regression were identified in 30 and 7% of the patients, respectively. Intraductal immune cells mainly comprised CD68+ macrophages and CD8+ T cells. Patients with stromal changes had significantly less influx of immune cells within the duct. DCIS regression was associated with an increased number of intraductal FOXP3+ T cells. The highest number of intraductal CD8+ T cells was seen in the ER+ HER2+ subtype. We suggest that DCIS-associated stromal changes prevent the interaction between immune cells and DCIS cells. However, in case of DCIS regression, we surmise a direct interaction between DCIS cells and immune cells, in particular FOXP3+ cells. Furthermore, the increased number of intraductal CD8+ T cells in the ER+ HER2+ DCIS subtype suggests a subtype-specific immune response, which is likely to play a role in the distinct biological behavior of different DCIS subtypes.

Deep-Learning-Based Characterization of Tumor-Infiltrating Lymphocytes in Breast Cancers From Histopathology Images and Multiomics Data

PURPOSE

Tumor-infiltrating lymphocytes (TILs) and their spatial characterizations on whole-slide images (WSIs) of histopathology sections have become crucial in diagnosis, prognosis, and treatment response prediction for different cancers. However, fully automatic assessment of TILs on WSIs currently remains a great challenge because of the heterogeneity and large size of WSIs. We present an automatic pipeline based on a cascade-training U-net to generate high-resolution TIL maps on WSIs.

METHODS

We present global cell-level TIL maps and 43 quantitative TIL spatial image features for 1,000 WSIs of The Cancer Genome Atlas patients with breast cancer. For more specific analysis, all the patients were divided into three subtypes, namely, estrogen receptor (ER)-positive, ER-negative, and triple-negative groups. The associations between TIL scores and gene expression and somatic mutation were examined separately in three breast cancer subtypes. Both univariate and multivariate survival analyses were performed on 43 TIL image features to examine the prognostic value of TIL spatial patterns in different breast cancer subtypes.

RESULTS

The TIL score was in strong association with immune response pathway and genes (eg, programmed death-1 and CLTA4). Different breast cancer subtypes showed TIL score in association with mutations from different genes suggesting that different genetic alterations may lead to similar phenotypes. Spatial TIL features that represent density and distribution of TIL clusters were important indicators of the patient outcomes.

CONCLUSION

Our pipeline can facilitate computational pathology-based discovery in cancer immunology and research on immunotherapy. Our analysis results are available for the research community to generate new hypotheses and insights on breast cancer immunology and development.

Ductal carcinoma in situ of the breast: immune cell composition according to subtype

Ductal carcinoma in situ of the breast includes several subtypes with a divergent biological behavior. Data regarding the composition of ductal carcinoma in situ-associated immune cells and their potential role in progression is limited. We studied ductal carcinoma in situ-associated immune response by characterizing immune cell subsets according to ductal carcinoma in situ subtypes. Ductal carcinoma in situ-associated tumor infiltrating lymphocyte (TIL) density was evaluated based on hematoxylin and eosin (H&E)-stained sections from 473 patients. Cases were subtyped based on ER, PR, and HER2. Patients were categorized as TIL-high or low. Ductal carcinoma in situ-associated immune cells of TIL-high cases were immunostained on whole slides with CD4, CD8, CD20, CD68, FOXP3, and PD-L1 (SP142 and SP263). In total, 131/473 patients (28.0%) were considered as TIL-high. The percentage of TIL-high cases was significantly higher in HER2+ and triple-negative ductal carcinoma in situ (P < 0.0001). Overall, no statistical difference in immune cell composition according to subtypes was found. However, individual subtype comparison showed that ER+ HER2+ cases had a significantly higher proportion of CD8+ T cells compared with triple-negative cases (P = 0.047). In TIL-high cases, PD-L1-SP142 expression on tumor cells was associated with subtype (P = 0.037); the lowest number of positive cases was observed in the HER2+ subtype (independent of ER). However, in TIL-high ductal carcinoma in situ, PD-L1 expression by both clones was limited. In conclusion, high numbers of TILs are predominantly observed in HER+ and triple negative ductal carcinoma in situ. The ER+ HER2+ subtype seems to attract a higher proportion of CD8+ T cells compared with the triple negative subtype. Among TIL-high cases, the HER2+ subgroup had the lowest PD-L1-SP142 expression on tumor cells. This suggests a more pronounced antitumor immunity in HER2+ ductal carcinoma in situ, which could play a role in its biological behavior.

Tumor-Infiltrating Lymphocytes in a Contemporary Cohort of Women with Ductal Carcinoma In Situ (DCIS)

BACKGROUND

Growing evidence suggests that the tumor immune microenvironment influences breast cancer development and prognosis. Density of tumor-infiltrating lymphocytes (TILs) within invasive breast cancer is correlated with response to therapy, especially in triple-negative disease. The clinical relevance and outcomes of TILs within ductal carcinoma in situ (DCIS) are less understood.

METHODS

Our institutional database of 668 patients with pure DCIS from 2010 to 2018 was queried. TILs were evaluated by International TILs Working Group guidelines. Percentage of TILs was assessed from the densest focus (hotspot) in one high-power field of stroma touching the basement membrane. Statistical methods included cluster analyses (to define sparse versus dense TILs), logistic, and Cox regression models.

RESULTS

Sixty-nine patients with DCIS and TILs were evaluated, of whom 54 (78%) were treated by breast-conserving surgery. Thirteen (19%) patients had ipsilateral recurrence. Each recurrence (n = 13) was matched to four controls (n = 56) based on date of surgery. Median follow-up was 6.7 years. TILs were defined as sparse (< 45%) or dense (≥ 45%). Dense TILs were associated with younger age (p = 0.045), larger tumor size (p < 0.001), high nuclear grade (p = 0.010), comedo histology (p = 0.033), necrosis (p = 0.027), estrogen receptor (ER) negativity (p = 0.037), and ipsilateral recurrence (p = 0.001). Nine patients with dense TILs had mean time to recurrence of 73.5 months compared with four patients with sparse TILs with mean time to recurrence of 97.9 months (p = 0.003).

CONCLUSIONS

Dense TILs were significantly associated with age, tumor size, nuclear grade, comedo histology, necrosis, and ER status and was a significant predictor of recurrence in patients with pure DCIS.

Saikosaponin A Inhibits Breast Cancer by Regulating Th1/Th2 Balance

Saikosaponin A (SSa) is isolated from the dried root of Radix Bupleuri, an herb widely used in traditional Chinese medicine, exerting antitumor activities. The T helper cell type 1(Th1)/Th2 balance is associated with antitumor immunity in breast cancer. The present study aimed to investigate the effects of SSa on Th1/Th2 balance in breast cancer and to explore the underlying mechanisms. Breast cancer in rats was induced by intragastrical administration of 7,12-dimethyl-benz[a] anthracene once (100 mg/kg). At d₉₁, the rats suffering from tumors were randomly divided into three groups and treated with vehicle solution (control group), tamoxifen (TAM group), and SSa (SSa group) daily for 56 days, respectively. The tumor volume reduction ratio and tumor cell proliferation were detected to assess the antitumor effect of SSa. The positive staining numbers of CD8+ and CD4+ T cells infiltrated in breast tumors were measured by immunohistochemistry to evaluate the antitumor immunity of SSa. Cytokine levels in serum secreted by Th1 cells [interferon gamma (IFN-γ), interleukin (IL)-12] and Th2 cells (IL-4, IL-10) were detected to evaluate Th1/Th2 balance. The related molecules of IL-12/signal transducers and activators of transcription 4 (STAT4) pathway were detected by immunohistochemistry staining, RT-PCR, and Western blot to explore the mechanisms of SSa. The results showed that, compared with the control group, SSa significantly inhibited tumor growth and tumor cell proliferation. SSa enhanced antitumor immunity, which was demonstrated as increased CD8+ T cells and CD4+ T cells infiltrated in tumors. SSa shifted Th1/Th2 balance toward Th1, which was confirmed as increased serum IFN-γ and IL-12 levels, while decreased serum IL-4 and IL-10 levels. SSa increased IL-12, IL-12 receptor, and phosphorylated STAT4 expressions to promote Th1 differentiation. In conclusion, the present work suggested that SSa could inhibit breast cancer growth by shifting Th1/Th2 balance toward Th1. The underlying mechanism may involve activation of the IL-12/STAT4 pathway that induced Th1 differentiation.

Circulating soluble levels of MIF in women with breast cancer in the molecular subtypes: relationship with Th17 cytokine profile

Breast cancer (BC) is a health problem worldwide; there is evidence that inflammatory cytokines are increased in BC. Macrophage migration inhibitory factor (MIF) has multiple effects on immune cells, inflammation and cancer. Besides, in previous studies, contradictory and uncertain results have been presented on the implication of Th17 cytokine profile in BC. The aim of this study was to evaluate the plasma levels of MIF and the Th17 cytokine profile in BC and their association with their molecular subtypes and clinical stage. A total of 150 women with BC of Ella Binational Breast Cancer Study and 60 healthy women (HW) were evaluated in cross-sectional study. The molecular subtypes were identified by immunohistochemistry. The plasma levels of MIF were quantified by ELISA and Th17 cytokine profile by multiplex system. MIF and IL-17 were significantly increased in BC versus HW (11.1 vs. 5.2 ng/mL and 14.8 pg/mL vs. 2.5 pg/mL p < 0.001, respectively). Our analysis showed that both MIF and IL-17A were associated with increased risk of breast cancer (OR 3.85 CI 95% 1.98-7.50 and OR 4.51 95% 1.83-11.15, respectively), higher in aggressive subtypes Luminal B, HER2 and TN. Likewise, we observed positive correlation between MIF and IL-17A (p < 0.001). In addition, IL-17E was lower in BC versus HW (p <0.001). Likewise, we observed a positive correlation between MIF and IL-17A (p < 0.001). In conclusion, both MIF and IL-17A were associated with high risk for breast cancer and aggressive molecular subtypes.

A retrospective alternative for active surveillance trials for ductal carcinoma in situ of the breast

Ductal carcinoma in situ (DCIS) of the breast is a nonobligate precursor of invasive breast cancer, accounting for 20 % of screen-detected breast cancers. Little is known about the natural progression of DCIS because most patients undergo surgery upon diagnosis. Many DCIS patients are likely being overtreated, as it is believed that only around 50 % of DCIS will progress to invasive carcinoma. Robust prognostic markers for progression to invasive carcinoma are lacking. In the past, studies have investigated women who developed a recurrence after breast-conserving surgery (BCS) and compared them with those who did not. However, where there is no recurrence, the patient has probably been adequately treated. The present narrative review advocates a new research strategy, wherein only those patients with a recurrence are studied. Approximately half of the recurrences are invasive cancers, and half are DCIS. So-called "recurrences" are probably most often the result of residual disease. The new approach allows us to ask: why did some residual DCIS evolve to invasive cancers and others not? This novel strategy compares the group of patients that developed in situ recurrence with the group of patients that developed invasive recurrence after BCS. The differences between these groups could then be used to develop a robust risk stratification tool. This tool should estimate the risk of synchronous and metachronous invasive carcinoma when DCIS is diagnosed in a biopsy. Identification of DCIS patients at low risk for developing invasive carcinoma will individualize future therapy and prevent overtreatment.

Protein profiling of fine-needle aspirates reveals subtype-associated immune signatures and involvement of chemokines in breast cancer

There are increasing demands for informative cancer biomarkers, accessible via minimally invasive procedures, both for initial diagnostics and for follow-up of personalized cancer therapy, including immunotherapy. Fine-needle aspiration (FNA) biopsy provides ready access to relevant tissue samples; however, the minute amounts of sample require sensitive multiplex molecular analysis to be of clinical biomarker utility. We have applied proximity extension assays (PEA) to analyze 167 proteins in FNA samples from patients with breast cancer (BC; n = 25) and benign lesions (n = 32). We demonstrate that the FNA BC samples could be divided into two main clusters, characterized by differences in expression levels of the estrogen receptor (ER) and the proliferation marker Ki67. This clustering corresponded to some extent to established BC subtypes. Our analysis also revealed several proteins whose expression levels differed between BC and benign lesions (e.g., CA9, GZMB, IL-6, VEGFA, CXCL11, PDL1, and PCD1), as well as several chemokines correlating with ER and Ki67 status (e.g., CCL4, CCL8, CCL20, CXCL8, CXCL9, and CXCL17). Finally, we also identified three signatures that could predict Ki67 status, ER status, and tumor grade, respectively, based on a small subset of proteins, which was dominated by chemokines. To our knowledge, expression profiles of CCL13 in benign lesions and BC have not previously been described but were shown herein to correlate with proliferation (P = 0.00095), suggesting a role in advanced BC. Given the broad functional range of the proteins analyzed, immune-related proteins were overrepresented among the observed alterations. Our pilot study supports the emerging role of chemokines in BC progression. Due to the minimally traumatic sampling and clinically important molecular information for therapeutic decisions, this methodology is promising for future immunoscoring and monitoring of treatment efficacy in BC.

Stromal characteristics are adequate prognosticators for recurrence risk in ductal carcinoma in situ of the breast

BACKGROUND

Ductal carcinoma in situ (DCIS) of the breast constitutes a heterogeneous group of non-obligate precursors for invasive breast cancer. To date, adequate risk stratification is lacking, which is presumed to result in overtreatment. We previously identified myxoid stromal architecture as a potential prognosticator for loco-regional recurrence. In the present study, we investigated the prognostic potential of stromal characteristics.

METHODS

Hematoxylin and eosin stained slides from 211 DCIS patients were reviewed. The following histological features were dichotomously assessed: nuclear grade, DCIS architecture, presence of necrosis, intraductal calcifications, stromal inflammation and myxoid stromal architecture. Loco-regional recurrences constituted the primary endpoint.

RESULTS

Cox regression analysis showed that high nuclear grade, myxoid stromal architecture and moderate to extensive stromal inflammation were significantly associated with decreased recurrence-free survival, independent of radiotherapy. Based on these features, a combined risk score (CRS) was calculated, ranging from zero to three. A high CRS of three was associated with significantly shorter recurrence-free survival. Nineteen patients had a CRS of three, of which three relapsed (15.7%), whereas only one out of 113 patients with a CRS of zero relapsed (0.9%).

CONCLUSIONS

We were able to validate our previously reported findings regarding the prognostic potential of myxoid periductal stroma in an independent DCIS patient cohort. A CRS based on nuclear grade, myxoid stromal architecture and stromal inflammation might facilitate discrimination of low risk from high risk patients. Consequently, the CRS may tailor adjuvant therapy. Future research should investigate whether radiotherapy can be safely omitted in patients with a low CRS.

Functional Role of miRNAs in the Progression of Breast Ductal Carcinoma in Situ

miRNAs are small RNAs that influence gene expression by targeting mRNAs. Depending on the function of their target genes, miRNAs may regulate the expression of oncogenes and tumor suppressors, thereby contributing to the promotion or inhibition of tumor progression. Ductal carcinoma in situ (DCIS), although often diagnosed as breast cancer, is a potential precursor to invasive ductal carcinoma. Many of the genetic events required for the invasive progression of DCIS occur at the preinvasive stage, and these events include changes in the expression of miRNAs. Aberrant expression of miRNAs can influence specific oncogenic or tumor-suppressive pathways required for breast cancer progression. miRNAs in DCIS have been shown to influence hormone signaling, cell-cell adhesion, epithelial-to-mesenchymal transition, transforming growth factor β signaling, maintenance of cancer stem cells, and modulation of the extracellular matrix. Additionally, extracellular DCIS miRNAs, such as those found in exosomes, may promote invasive progression by modifying the tumor microenvironment. Here, we review the miRNAs that have been identified in DCIS and how they may contribute to the progression to invasive disease. We also touch on the current state of miRNA therapy development, including the current challenges, and discuss the key future perspectives for research into miRNA function for the purpose of miRNA therapy development for DCIS.