Potential candidate biomarkers for heterogeneity in triple-negative breast cancer (TNBC)

Survival according to the site of metastasis in triple-negative breast cancer patients: The Peruvian experience

BACKGROUND

Evidence regarding differences in survival associated with the site of metastasis in triple-negative breast cancer (TNBC) remains limited. Our aim was to analyze the overall survival (OS), distant relapse free survival (DRFS), and survival since the diagnosis of the relapse (MS), according to the side of metastasis.

METHODS

This was a retrospective study of TNBC patients with distant metastases at the Instituto Nacional de Enfermedades Neoplasicas (Lima, Peru) from 2000 to 2014. Prognostic factors were determined by multivariate Cox regression analysis.

RESULTS

In total, 309 patients were included. Regarding the type of metastasis, visceral metastasis accounted for 41% and the lung was the most frequent first site of metastasis (33.3%). With a median follow-up of 10.2 years, the 5-year DRFS and OS were 10% and 26%, respectively. N staging (N2-N3 vs. N0, HR = 1.49, 95%CI: 1.04-2.14), metastasis in visceral sites (vs. bone; HR = 1.55, 95%CI: 0.94-2.56), the central nervous system (vs. bone; HR = 1.88, 95% CI: 1.10-3.22), and multiple sites (vs. bone; HR = 2.55, 95%CI:1.53-4.25) were prognostic factors of OS whereas multiple metastasis (HR = 2.30, 95% CI: 1.42-3.72) was a predictor of MS. In terms of DRFS, there were no differences according to metastasis type or solid organ.

CONCLUSION

TNBC patients with multiple metastasis and CNS metastasis have an increased risk of death compared to those with bone metastasis in terms of OS and MS.

Emerging Prognostic and Predictive Significance of Stress Keratin 17 in HPV-Associated and Non HPV-Associated Human Cancers: A Scoping Review

A growing body of literature suggests that the expression of cytokeratin 17 (K17) correlates with inferior clinical outcomes across various cancer types. In this scoping review, we aimed to review and map the available clinical evidence of the prognostic and predictive value of K17 in human cancers. PubMed, Web of Science, Embase (via Scopus), Cochrane Central Register of Controlled Trials, and Google Scholar were searched for studies of K17 expression in human cancers. Eligible studies were peer-reviewed, published in English, presented original data, and directly evaluated the association between K17 and clinical outcomes in human cancers. Of the 1705 studies identified in our search, 58 studies met criteria for inclusion. Studies assessed the prognostic significance (n = 54), predictive significance (n = 2), or both the prognostic and predictive significance (n = 2). Altogether, 11 studies (19.0%) investigated the clinical relevance of K17 in cancers with a known etiologic association to HPV; of those, 8 (13.8%) were focused on head and neck squamous cell carcinoma (HNSCC), and 3 (5.1%) were focused on cervical squamous cell carcinoma (SCC). To date, HNSCC, as well as triple-negative breast cancer (TNBC) and pancreatic cancer, were the most frequently studied cancer types. K17 had prognostic significance in 16/17 investigated cancer types and 43/56 studies. Our analysis suggests that K17 is a negative prognostic factor in the majority of studied cancer types, including HPV-associated types such as HNSCC and cervical cancer (13/17), and a positive prognostic factor in 2/17 studied cancer types (urothelial carcinoma of the upper urinary tract and breast cancer). In three out of four predictive studies, K17 was a negative predictive factor for chemotherapy and immune checkpoint blockade therapy response.

Panitumumab-DOTA-111In: An Epidermal Growth Factor Receptor Targeted Theranostic for SPECT/CT Imaging and Meitner-Auger Electron Radioimmunotherapy of Triple-Negative Breast Cancer

Epidermal growth factor receptors (EGFR) are overexpressed in triple-negative breast cancer (TNBC) and are an attractive target for the development of theranostic radiopharmaceuticals. We studied anti-EGFR panitumumab labeled with ¹¹¹In (panitumumab-DOTA-¹¹¹In) for SPECT/CT imaging and Meitner-Auger electron (MAE) radioimmunotherapy (RIT) of TNBC. Panitumumab-DOTA-¹¹¹In was bound, internalized, and routed to the nucleus in MCF7, MDA-MB-231/Luc, and MDA-MB-468 human breast cancer (BC) cells dependent on the EGFR expression level (1.5 × 10⁴, 1.7 × 10⁵, or 1.3 × 10⁶ EGFR/cell, respectively). The absorbed dose in the nuclei of MCF7, MDA-MB-231/Luc, and MDA-MB-468 cells incubated with 4.4 MBq of panitumumab-DOTA-¹¹¹In (20 nM) was 1.20 ± 0.02, 2.2 ± 0.1, and 25 ± 2 Gy, respectively. The surviving fraction (SF) of MDA-MB-231/Luc cells treated with panitumumab-DOTA-¹¹¹In (10-300 nM; 1.5 MBq/μg) was reduced as the absorbed dose in the cell increased, with clonogenic survival reduced to an SF = 0.12 ± 0.05 at 300 nM corresponding to 12.7 Gy. The SFs of MDA-MB-468, MDA-MB-231/Luc, and MCF7 cells treated with panitumumab-DOTA-¹¹¹In (20 nM; 1.7 MBq/μg) were <0.01, 0.56 ± 0.05, and 0.67 ± 0.04, respectively. Unlabeled panitumumab had no effect on SF, and irrelevant IgG-DOTA-¹¹¹In only modestly reduced the SF of MDA-MB-231/Luc cells but not MCF7 or MDA-MB-468 cells. The cytotoxicity of panitumumab-DOTA-¹¹¹In was mediated by increased DNA double-strand breaks (DSB), cell cycle arrest at G2/M-phase and apoptosis measured by immunofluorescence detection by flow cytometry. MDA-MB-231/Luc tumors in the mammary fat pad (MFP) of NRG mice were clearly imaged with panitumumab-DOTA-¹¹¹In by microSPECT/CT at 4 days postinjection (p.i.), and biodistribution studies revealed high tumor uptake [18 ± 2% injected dose/g (% ID/g] and lower normal tissue uptake (<10% ID/g). Administration of up to 24 MBq (15 μg) of panitumumab-DOTA-¹¹¹In to healthy NRG mice caused no major hematological, renal, or hepatic toxicity with no decrease in body weight. Treatment of NOD SCID mice with MDA-MB-231 tumors with panitumumab-DOTA-¹¹¹In (22 MBq; 15 μg) slowed tumor growth. The mean time for tumors to reach a volume of ≥500 mm³ was 61 ± 5 days for RIT with panitumumab-DOTA-¹¹¹In compared to 42 ± 6 days for mice treated with irrelevant IgG₂-DOTA-¹¹¹In (P < 0.0001) and 35 ± 3 days for mice receiving 0.9% NaCl (P < 0.0001). However, tumors regrew at later time points. The median survival of mice treated with panitumumab-DOTA-¹¹¹In was 70 days versus 46 days for IgG₂-DOTA-¹¹¹In (P < 0.0001) or 40 days for 0.9% NaCl (P < 0.0001). We conclude that panitumumab-DOTA-¹¹¹In is a promising theranostic agent for TNBC. Increasing the administered amount of panitumumab-DOTA-¹¹¹In and/or combination with radiosensitizing PARP inhibitors used for treatment of patients with TNBC may provide a more durable response to RIT.

Prognostic Value of HER2-Low Expression in Non-Metastatic Triple-Negative Breast Cancer and Correlation with Other Biomarkers

HER2-low breast cancer (i.e., HER 1+ or 2+, without gene amplification) is an emerging subtype for which very few data are available, especially within the triple-negative breast cancer (TNBC) group. Our aim was to evaluate HER2 expression and its prognostic value in a large retrospective series of patients with non-metastatic TNBC (median age: 57.7 years; range: 28.5-98.6). Among the 296 TNBC samples, 83.8% were HER2 0, 13.5% were HER2 1+, and 2.7% were HER2 2+ (HercepTest^TM and 2018 ASCO/CAP guidelines for HER2 scoring). CK5/6 and/or EGFR-expressing androgen receptors and FOXA1-expressing tumors were classified as basal-like (63.8%) and molecular apocrine-like (MA, 40.2%), respectively. Compared with HER2 0 tumors, HER2 1+/2+ tumors exhibited a lower histological grade (1/2) (35.4% vs. 18.2%, p = 0.007) and MA profile (57.5% vs. 36.7%, p = 0.008). Moreover, patients with HER2 1+/2+ tumors were older (p = 0.047). After a median follow-up of 9.7 years, HER2 2+ tumors (compared with HER2 0/1+ tumors) were associated with worse relapse-free survival (RFS) (HR = 3.16, 95% CI [1.27; 7.85], p = 0.034) in a univariate analysis. Overall survival (OS) and RFS were not different in the HER2 0 and 1+/2+ groups. HER2 levels were not significantly associated with OS or RFS in a multivariate analysis.

Cell Heterogeneity Analysis in Single-Cell RNA-seq Data Using Mixture Exponential Graph and Markov Random Field Model

Advanced single-cell profiling technologies promote exploration of cell heterogeneity, and clustering of single-cell RNA (scRNA-seq) data enables discovery of coexpression genes and network relationships between genes. In particular, single-cell profiling of circulating tumor cells (CTCs) can provide unique insights into tumor heterogeneity (including in triple-negative breast cancer (TNBC)), while scRNA-seq leads to better understanding of subclonal architecture and biological function. Despite numerous reports suggesting a direct correlation between circulating tumor cells (CTCs) and poor clinical outcomes, few studies have provided a thorough heterogeneity characterization of CTCs. In addition, TNBC is a disease with not only intertumor but also intratumor heterogeneity and represents various biological distinct subgroups that may have relationships with immune functions that are not clearly established yet. In this article, we introduce a new scheme for detecting genotypic characterization of single-cell heterogeneities and apply it to CTC and TNBC single-cell RNA-seq data. First, we use an existing mixture exponential family graph model to partition the cell-cell network; then, with the Markov random field model, we obtain more flexible network rewiring. Finally, we find the cell heterogeneity and network relationships according to different high coexpression gene modules in different cell subsets. Our results demonstrate that this scheme provides a reasonable and effective way to model different cell clusters and different biological enrichment gene clusters. Thus, using different internal coexpression genes of different cell clusters, we can infer the differences in tumor composition and diversity.

Clinicopathological Correlates of γδ T Cell Infiltration in Triple-Negative Breast Cancer

Simple Summary

The prognostic impact of the different tumor-infiltrating lymphocyte (TIL) subpopulations remains debated in solid cancers. We investigated the clinicopathological correlates and prognostic impact of TILs, particularly of γδ T cells, in 162 triple-negative breast cancer (TNBC) patients. A high γδ T cell density was significantly associated with younger age, higher tumor histological grade, adjuvant chemotherapy, BRCA1 promoter methylation, TIL density, and PD-L1 and PD-1 expression. In multivariate analyses, γδ T cell infiltration was an independent prognostic factor. However, this prognostic impact varied according to the tumor PIK3CA mutational status. High γδ T cell infiltration was associated with better survival in patients with PIK3CA wild-type tumors, without significant difference in the PIK3CA-mutated tumor subgroup. Altogether, these data suggest that high γδ T cell infiltrate is correlated with immune infiltration and might represent a prognostic tool in TNBC patients.

Abstract

The prognostic impact of the different tumor-infiltrating lymphocyte (TIL) subpopulations in solid cancers is still debated. Here, we investigated the clinicopathological correlates and prognostic impact of TILs, particularly of γδ T cells, in 162 patients with triple-negative breast cancer (TNBC). A high γδ T cell density (>6.625 γδ T cells/mm²) was associated with younger age (p = 0.008), higher tumor histological grade (p = 0.002), adjuvant chemotherapy (p = 0.010), BRCA1 promoter methylation (p = 0.010), TIL density (p < 0.001), and PD-L1 (p < 0.001) and PD-1 expression (p = 0.040). In multivariate analyses, γδ T cell infiltration (cutoff = 6.625 γδ T cells/mm²) was an independent prognostic factor (5-year relapse-free survival: 63.3% vs. 89.8%, p = 0.027; 5-year overall survival: 73.8% vs. 89.9%, p = 0.031, for low vs. high infiltration). This prognostic impact varied according to the tumor PIK3CA mutational status. High γδ T cell infiltration was associated with better survival in patients with PIK3CA wild-type tumors, but the difference was not significant in the subgroup with PIK3CA-mutated tumors. Altogether, these data suggest that high γδ T cell infiltrate is correlated with immune infiltration and might represent a candidate prognostic tool in patients with TNBC.

BRCA1 Promoter Hypermethylation is Associated with Good Prognosis and Chemosensitivity in Triple-Negative Breast Cancer

The aberrant hypermethylation of BRCA1 promoter CpG islands induces the decreased expression of BRCA1 (Breast Cancer 1) protein. It can be detected in sporadic breast cancer without BRCA1 pathogenic variants, particularly in triple-negative breast cancers (TNBC). We investigated BRCA1 hypermethylation status (by methylation-specific polymerase chain reaction (MS-PCR) and MassARRAY^® assays), and BRCA1 protein expression using immunohistochemistry (IHC), and their clinicopathological significance in 248 chemotherapy-naïve TNBC samples. Fifty-five tumors (22%) exhibited BRCA1 promoter hypermethylation, with a high concordance rate between MS-PCR and MassARRAY^® results. Promoter hypermethylation was associated with reduced IHC BRCA1 protein expression (p = 0.005), and expression of Programmed death-ligand 1 protein (PD-L1) by tumor and immune cells (p = 0.03 and 0.011, respectively). A trend was found between promoter hypermethylation and basal marker staining (p = 0.058), and between BRCA1 expression and a basal-like phenotype. In multivariate analysis, relapse-free survival was significantly associated with N stage, adjuvant chemotherapy, and histological subtype. Overall survival was significantly associated with T and N stage, histology, and adjuvant chemotherapy. In addition, patients with tumors harboring BRCA1 promoter hypermethylation derived the most benefit from adjuvant chemotherapy. In conclusion, BRCA1 promoter hypermethylation is associated with TNBC sensitivity to adjuvant chemotherapy, basal-like features and PD-L1 expression. BRCA1 IHC expression is not a good surrogate marker for promoter hypermethylation and is not independently associated with prognosis. Association between promoter hypermethylation and sensitivity to Poly(ADP-ribose) polymerase PARP inhibitors needs to be evaluated in a specific series of patients.

circRNA of AR-suppressed PABPC1 91 bp enhances the cytotoxicity of natural killer cells against hepatocellular carcinoma via upregulating UL16 binding protein 1

Hepatocellular carcinoma (HCC) is a heterogeneous malignancy type with limited approaches for treatment. Additionally, inappropriate immune therapy indicates that the understanding the underlying mechanism of HCC is necessary. The aim of the present study was to investigate the influence of a novel circular RNA (circRNA), circRNA of AR-suppressed PABPC1 91 bp (CircARSP91), on immune surveillance induced by natural killer (NK) cells. An in vitro cell cytotoxicity assay was performed to determine the cytotoxicity of NK cells against HCC cells. A specific plasmid for circRNA overexpression was used to establish stable cell lines. Additionally, samples from patients with HCC were analyzed to determine the association between the present in vitro data and those of clinical settings. CircARSP91 could increase the susceptibility of HCC cells to NK cell cytotoxicity. Following screening multiple factors that could influence the activation of NK cells, it was determined that such a phenotype may be caused by upregulating UL16 binding protein 1 (ULBP1) expression in HCC cells at the mRNA and protein levels. Additionally, the data generated from patient samples significantly support a positive association between CircARSP91 and ULBP1. In conclusion, CircARSP91 could enhance innate immune surveillance by strengthening the cytotoxicity of NK cells, implying that circRNA may serve a role in tumor immunity.

PP2A as the Main Node of Therapeutic Strategies and Resistance Reversal in Triple-Negative Breast Cancer

Triple negative breast cancer (TNBC), is defined as a type of tumor lacking the expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). The ER, PR and HER2 are usually the molecular therapeutic targets for breast cancers, but they are ineffective for TNBC because of their negative expressions, so chemotherapy is currently the main treatment strategy in TNBC. However, drug resistance remains a major impediment to TNBC chemotherapeutic treatment. Recently, the protein phosphatase 2A (PP2A) has been found to regulate the phosphorylation of some substrates involved in the relevant target of TNBC, such as cell cycle control, DNA damage responses, epidermal growth factor receptor, immune modulation and cell death resistance, which may be the effective therapeutic strategies or influence drug sensitivity to TNBCs. Furthermore, PP2A has also been found that could induce ER re-expression in ER-negative breast cancer cells, and which suggests PP2A could promote the sensitivity of tamoxifen to TNBCs as a resistance reversal agent. In this review, we will summarize the potential therapeutic value of PP2A as the main node in developing targeting agents, disrupting resistance or restoring drug sensitivity in TNBC.

Estrogen receptor-α promoter methylation is a biomarker for outcome prediction of cisplatin resistance in triple-negative breast cancer

A number of previous studies have indicated the presence of a link between estrogen receptor-α (ERα) methylation and triple-negative breast cancer (TNBC). However, the association between ERα methylation and drug resistance during the treatment of TNBC remains unclear. Methylation-specific polymerase chain reaction was used to investigate the methylation of ERα in the genomic DNA of 35 patients with TNBC who were defined as cisplatin-based chemotherapy-resistant using chemosensitivity testing. Survival probabilities by covariates were assessed using Kaplan-Meier estimator survival analysis and Cox's proportional hazards models, adjusting for age, menopausal status, tumor size, lymph node metastasis and ERα promoter DNA methylation. Of the 35 patients with TNBC analyzed, 8 exhibited ERα promoter DNA methylation. Cisplatin resistance was confirmed to be overwhelmingly associated with ERα methylation by univariate and multivariate analysis. Even in a limited analysis in patients with ERα methylation, the results generated from methylated tumor tissue and unmethylated tumor tissue revealed that expression of breast cancer type 1/2 susceptibility proteins was increased in ERα-methylated breast tumor tissue compared with in unmethylated tissue. The ERα methylation group tended to have significantly shorter progression-free (P=0.010) and overall (P=0.023) survival times compared with those in the unmethylated group. Similarly, shorter progression-free (P=0.024) and overall (P=0.018) survival times were observed in the cisplatin-resistant group compared with the cisplatin-non-resistant group. ERα methylation predicts a poor clinical outcome for patients with TNBC. The results of the present study indicated that ERα methylation may be a candidate surrogate biomarker for outcome prediction and cisplatin resistance in TNBC. Further investigation is required to identify potential biomarkers in a larger cohort in a prospective study.

Screening and identification of potential biomarkers in triple-negative breast cancer by integrated analysis

Triple-negative breast cancer (TNBC) has attracted great attention due to its unique biology, poor prognosis, and aggressiveness. TNBC patients are more likely to suffer from metastasis. We screened and identified the TNBC-specific genes as potential biomarkers. A total of 167 breast cancer samples (45 TNBC and 122 non-TNBC) were used in the integrated analysis. Gene expression microarrays were used to screen the differentially expressed genes. We identified 65 core DEGs. According to the GO and KEGG analysis, the gene function enrichment in TNBC was revealed, such as basal cell carcinoma, prostate cancer, oocyte meiosis and choline metabolism in cancer pathways. Moreover, the PPI network reconstruction would benefit the screening of hubs. A RFS analysis of TNBC-specific genes was also conducted. RT-PCR was used to validate the expression pattern of hubs in TNBC. Finally, nine genes were identified and all of them were novel, specific and higher dysregulation expressed genes in TNBC. Such that, these genes will serve as potential biomarkers in TNBC and benefit further research in TNBC.

The role of BRCA status on prognosis in patients with triple-negative breast cancer

Studies have showed that dysfunction in the breast cancer susceptibility gene (BRCA) is associated with triple-negative breast cancer (TNBC); however, its effect on patient survival remains controversial. We investigated the distribution of BRCA1/2 mutations in unselected Chinese patients with TNBC and explored their roles in prognosis. Then a systematic review and meta-analysis were performed to evaluate the prognostic role of BRCA dysfunction, including BRCA1/2 germline/somatic mutations, BRCA1 promoter methylation, and low BRCA1 protein expression in TNBC patients. Pooled hazard ratios with 95% confidence intervals were estimated to determine the association between BRCA dysfunction and survival. Our results showed a high frequency of BRCA1/2 mutations, especially germline BRCA1 variants, were associated with bilateral breast cancer. Although no correlations were found between BRCA1/2 mutations and recurrence-free survival (RFS) or overall survival (OS). In the meta-analysis, patients with BRCA1 promoter methylation showed poor OS. However, there was a favorable impact on disease free survival (DFS) for TNBC patients with BRCA1 promoter methylation when received adjuvant-chemotherapy. In conclusion, BRCA1/2 mutations were associated with bilateral breast cancer and BRCA1 promoter methylation may have a prognostic effect on TNBC.

Triple negative breast cancer chemosensitivity and chemoresistance: current advances in biomarkers indentification

INTRODUCTION

Triple negative breast cancer (TNBC) is a heterogeneous clinicopathological entity constituting approximately 15 - 20% of all breast cancer (BC) patients. It shows high recurrence rate and poor prognosis. At this juncture, because of the lack of specific targeted therapies available and the development in patients of resistance to some therapeutic agents, clinical and translational settings have gained importance over the past decades.

AREAS COVERED

The development of novel, safe and effective alternatives for the treatment of TNBC are in high demand. Therefore, this review aims to summarize the state of the art of TNBC, its current therapies and potential therapeutic targets. In particular, focus is put on recent advances regarding the identification of emerging biomarkers as prognostic and/or predictive markers, including surrogate markers for molecular tumor subtyping and identifying potential responders to new therapies.

EXPERT OPINION

Effective development of informative markers could constitute an important armamentarium tool for identifying appropriate therapies to challenge the aggressiveness of TNBC.

High EGFR protein expression and exon 9 PIK3CA mutations are independent prognostic factors in triple negative breast cancers

BACKGROUND

Triple negative breast cancers (TNBC) are a more aggressive subset of breast cancer. A better understanding of its biology could allow the rational development of targeted therapies.

METHODS

We extensively analyzed the EGFR/PI3K/PTEN axis in a large, homogeneous population of TNBC to help defining the putative role of anti-EGFR and -PI3K targeted therapies in this setting. EGFR gene amplification, EGFR protein expression, PIK3CA and PTEN gene alterations (two members of EGFR downstream pathways) and their clinicopathological and prognostic implications were analyzed in 204 TNBC samples from European patients.

RESULTS

EGFR amplification was detected in 18 of the 204 TNBC specimens (8.9 %) and was significantly associated with higher EGFR protein levels. Fourteen PIK3CA mutations were identified in exon 9 (6.7 %), and 17 in exon 20 (8.3 %). PIK3CA mutations, especially in exon 9, were significantly associated with grade I-II tumors. PTEN deletions were detected in 43 samples (21.50 %) and were significantly associated with grade III tumors (p < 0.001). Univariate analysis showed a significant association between relapse-free survival (RFS), T and N stage and exon 9 PIK3CA mutations. Overall survival was significantly associated with T stage, N stage and adjuvant chemotherapy, which was administered to 70.3 % of patients. In multivariate analyses, T stage, N stage, presence of exon 9 PIK3CA mutations and high EGFR protein level were independent poor prognostic factors for RFS, while adjuvant chemotherapy was associated with a better outcome.

CONCLUSIONS

High EGFR protein expression and exon 9 PIK3CA activating mutations are independent prognostic factors in TNBC. The efficacy of anti-PI3K targeted therapies needs to be evaluated in this setting.

Survival and local control rates of triple-negative breast cancer patients treated with boost-IOERT during breast-conserving surgery

AIM

The purpose of this work was to retrospectively evaluate survival and local control rates of triple-negative breast cancer subtypes classified as five marker negative (5NP) and core basal (CB), respectively, after breast-conserving surgery and intraoperative boost radiotherapy with electrons (IOERT) followed by whole breast irradiation.

METHODS AND MATERIALS

A total of 71 patients with triple-negative breast cancer were enrolled, who were treated with lumpectomy, axillary lymph node dissection, and IOERT with 9.6 Gy (median Dmax) followed by normofractionated whole breast irradiation to median total doses of 54 Gy. Chemotherapy was applied in a neoadjuvant (12 %), adjuvant (75 %), or combinational setting (7 %).

RESULTS

After a median follow-up of 97 months (range 4-170 months), 5 in-breast recurrences were detected (7.0 %). For all patients, 8-year actuarial rates for local control, metastases-free survival, disease-specific survival, and overall survival amounted to 89, 75, 80, and 69 %, respectively. All local recurrences occurred in grade 3 (G3) tumors irrespective of their specific immunohistochemical phenotype; thus, the local control rate for grades 1/2 (G1/2) was 100 % for both 5NP and CB, while for G3 it was 88 % for 5NP and 90 % for CB (p = 0.65 and 0.82, respectively, n.s.). For disease-specific survival, only the difference of the best-prognosis group 5-NP/G3 vs. the worst-prognosis cohort CB/G1/2 was statistically significant: 90 % vs. 54 % (p = 0.03).

CONCLUSION

Boost-IOERT provides acceptable long-term in-breast control in triple negative breast cancer. The best subgroup in terms of disease-specific survival was represented by 5NP in combination with tumor grading G3.

Combined microRNA and ER expression: a new classifier for familial and sporadic breast cancer patients

BACKGROUND

The role of miRNAs in familial breast cancer (fBC) is poorly investigated as also in the BRCA-like tumors. To identify a specific miRNA expression pattern which could allow a better fBC classification not only based on clinico-pathological and immunophenotypical parameters we analyzed miRNA profile in familial and sporadic samples. Moreover since BRCA1 tumors and sporadic triple negative (TN) breast tumors share similarities regarding clinical outcomes and some histological characteristics, we focused on TN and not TN cases.

METHODS

The sample set included fresh frozen tissue samples, including 39 female fBCs (19 BRCA-related and 20 BRCAX) and 12 male fBC (BRCAX). Moreover, we considered TN and non TN (NTN), 21 BRCA-related and 27 sporadic BCs. MiRNA profiling was performed through GeneChip miRNA v.1.0 Array (Affymetrix). ANOVA, hierarchical and consensus clustering analyses allowed identification of pattern of expression of miRNAs and pathway enrichment analysis, considering validated target genes, was carried out to achieve a deeper biological understanding.

RESULTS

ANOVA test led to the identification of 53 deregulated miRNAs; hierarchical and consensus clustering of female fBCs (fFBCs) and male fBCs (fMBCs) highlighted the presence of 3 sample clusters named FBC1, FBC2 and FBC3. We found a correlation between ER-status and the three sample clusters. The three clusters are distinct by a different expression of two clusters of miRNAs (CLU1 and CLU2), which resulted to be different in targeted pathways. In particular, CLU1 targets cellular pathways and CLU2 is involved in epigenetic activities. Considering TN and NTN BRCA-related and sporadic tumors, a hierarchical clustering identified two clusters of miRNAs, which were not so different from CLU1 and CLU2, both in miRNA content and targeted pathways.

CONCLUSIONS

Our results highlighted the importance of miRNA regulation to better clarify similarities and differences between familial and sporadic BC groups.

FOXP3 transcription factor: a candidate marker for susceptibility and prognosis in triple negative breast cancer

Triple negative breast cancer (TNBC) is a relevant subgroup of neoplasia which presents negative phenotype of estrogen and progesterone receptors and has no overexpression of the human epidermal growth factor 2 (HER2). FOXP3 (forkhead transcription factor 3) is a marker of regulatory T cells (Tregs), whose expression may be increased in tumor cells. This study aimed to investigate a polymorphism (rs3761548) and the protein expression of FOXP3 for a possible involvement in TNBC susceptibility and prognosis. Genetic polymorphism was evaluated in 50 patients and in 115 controls by allele-specific PCR (polymerase chain reaction). Protein expression was evaluated in 38 patients by immunohistochemistry. It was observed a positive association for homozygous AA (OR = 3.78; 95% CI = 1.02–14.06) in relation to TNBC susceptibility. Most of the patients (83%) showed a strong staining for FOXP3 protein in the tumor cells. In relation to FOXP3-positive infiltrate, 47% and 58% of patients had a moderate or intense intratumoral and peritumoral mononuclear infiltrate cells, respectively. Tumor size was positively correlated to intratumoral FOXP3-positive infiltrate (P = 0.026). In conclusion, since FOXP3 was positively associated with TNBC susceptibility and prognosis, it seems to be a promising candidate for further investigation in larger TNBC samples.

Molecular markers for breast cancer: prediction on tumor behavior

Breast cancer is one of the most common cancers with greater than 1,300,000 cases and 450,000 deaths each year worldwide. The development of breast cancer involves a progression through intermediate stages until the invasive carcinoma and finally into metastatic disease. Given the variability in clinical progression, the identification of markers that could predict the tumor behavior is particularly important in breast cancer. The determination of tumor markers is a useful tool for clinical management in cancer patients, assisting in diagnostic, staging, evaluation of therapeutic response, detection of recurrence and metastasis, and development of new treatment modalities. In this context, this review aims to discuss the main tumor markers in breast carcinogenesis. The most well-established breast molecular markers with prognostic and/or therapeutic value like hormone receptors, HER-2 oncogene, Ki-67, and p53 proteins, and the genes for hereditary breast cancer will be presented. Furthermore, this review shows the new molecular targets in breast cancer: CXCR4, caveolin, miRNA, and FOXP3, as promising candidates for future development of effective and targeted therapies, also with lower toxicity.

Another review on triple negative breast cancer. Are we on the right way towards the exit from the labyrinth?

Triple negative breast cancer is a heterogeneous group of tumors, lacking the expression of estrogen, progesterone and HER-2 receptors. As frequency, it accounts about 15-20% of all breast cancers. Although in the last years there was a "boom" in publishing over this issue, multiple molecular classifications being elaborated, "the triple negative breast cancer odyssey " is still far away from ending, as the complicated molecular pathways of pathogenesis and drug resistance mechanisms remain yet insufficiently explored. The aim of this review is presentation of molecular signatures that could predict outcome and drug resistance in triple negative breast cancer.

Raloxifene reduces triple-negative breast cancer tumor growth and decreases EGFR expression

The poor prognosis of patients with triple-negative breast cancer (TNBC) and the lack of targeted treatments have raised the need for alternative therapies. Previous studies have suggested an effect of raloxifene, a selective estrogen receptor modulator that is independent of the estrogen receptor (ER). Therefore, we assessed the therapeutic value of raloxifene in TNBC mouse models. Mice received a daily oral treatment with different doses of raloxifene. Tumor progression was monitored weekly; in addition microvessel density, proliferation, migration and invasion, apoptosis and tumorigenicity were analyzed. This study demonstrates that raloxifene (0.85 mg/kg) prevents TNBC tumor growth and induces tumor regression. The treated tumors showed a 54% decreased microvascular density and proliferation and a 7-fold increase in apoptosis. The underlying therapeutic mechanism of raloxifene was associated with a 27-fold decrease in the expression of the epidermal growth factor receptor (EGFR). Moreover, raloxifene promoted the translocation of EGFR into endosomes associated with decreased cell migration, cell invasion and tumorigenicity in vitro. Together, these data showed that raloxifene acts independently of the ER and may be relevant for the treatment as well as control the progression of TNBC.

Prognostic impact of FOXP3 expression in triple-negative breast cancer

BACKGROUND

Forkhead Box Protein 3 (FOXP3) is a marker for immunosuppressive CD4+CD25+ regulatory T cells (Tregs). We investigated whether there were significant numbers of FOXP3-positive Tregs in triple-negative breast cancer (TNBC) using immunohistochemistry, and whether the presence of FOXP3-positive Tregs was associated with other prognostic factors, such as stage or histologic grade. We investigated the number of tumor-infiltrating FOXP3-positive Tregs in formalin-fixed TNBC specimens obtained from patients who received palliative treatment between 1999 and 2007.

MATERIAL AND METHODS

Immunohistochemistry was used to assess the number of CD4+, CD25+, and FOXP3+ Tregs in tumor tissue and normal breast tissue from 86 TNBC patients. Univariate and multivariate analyses evaluated outcomes according to the number of FOXP3-positive Tregs.

RESULTS

Of the 86 tumor specimens, 22 (25.6%) expressed more than 15 FOXP3-positive Tregs per 10 high power fields in the peritumoral area. On multivariate analysis, staining showing ≥ 15 FOXP3-positive Tregs was an independent prognostic factor for overall survival and progression free survival with hazard ratios of 2.4 (95% CI 1.0-5.6; p = 0.049) and 2.0 (95% CI 1.1-3.6; p = 0.032), respectively. In TNBC, FOXP3-positive Tregs had stronger prognostic significance than did FOXP3-negative Tregs. The finding of improved survival associated with highly infiltrating FOXP3-positive Tregs in TNBC contrasted with several other types of solid cancer.

CONCLUSION

TNBC may be differently driven by FOXP3 via an immune mechanism. The inclusion of FOXP3+ Tregs may help to improve prognostication for TNBC.

In Vitro Enhanced Sensitivity to Cisplatin in D67Y BRCA1 RING Domain Protein

BRCA1 is a tumor suppressor protein involved in maintaining genomic integrity through multiple functions in DNA damage repair, transcriptional regulation, cell cycle checkpoint, and protein ubiquitination. The BRCA1-BARD1 RING complex has an E3 ubiquitin ligase function that plays essential roles in response to DNA damage repair. BRCA1-associated cancers have been shown to confer a hypersensitivity to chemotherapeutic agents. Here, we have studied the functional consequence of the in vitro E3 ubiquitin ligase activity and cisplatin sensitivity of the missense mutation D67Y BRCA1 RING domain. The D67Y BRCA1 RING domain protein exhibited the reduced ubiquitination function, and was more susceptible to the drug than the D67E or wild-type BRCA1 RING domain protein. This evidence emphasized the potential of using the BRCA1 dysfunction as an important determinant of chemotherapy responses in breast cancer.