Expression of ARs in triple negative breast cancer tumors: a potential prognostic factor?

Background/aim

In light of the controversial published literature, this study aims to examine the potential prognostic role of AR immunohistochemical expression in triple negative breast cancer (TNBC).

Patients and methods

Ninety patients with TNBC were included in this study; the associations between AR expression (Allred score), clinicopathological variables (stage, grade, histological subtype, tumor size, nodal status, age at diagnosis, Ki67 expression, and p53 expression), and overall survival were evaluated.

Results

AR expression was not associated with stage, grade, histological subtype, tumor size, nodal status, age at diagnosis, Ki67 expression, and p53 expression. AR immunopositivity was not associated with overall survival either at the univariate or at the multivariate Cox regression analysis (multivariate hazard ratio =0.66, 95% confidence interval: 0.26–1.70, P=0.393).

Conclusion

AR expression does not seem to play a prognostic role in TNBC.

Biological network-driven gene selection identifies a stromal immune module as a key determinant of triple-negative breast carcinoma prognosis

Triple-negative breast cancer (TNBC) is a heterogeneous group of aggressive breast cancers for which no targeted treatment is available. Robust tools for TNBC classification are required, to improve the prediction of prognosis and to develop novel therapeutic interventions. We analyzed 3,247 primary human breast cancer samples from 21 publicly available datasets, using a five-step method: (1) selection of TNBC samples by bimodal filtering on ER-HER2 and PR, (2) normalization of the selected TNBC samples, (3) selection of the most variant genes, (4) identification of gene clusters and biological gene selection within gene clusters on the basis of String© database connections and gene-expression correlations, (5) summarization of each gene cluster in a metagene. We then assessed the ability of these metagenes to predict prognosis, on an external public dataset (METABRIC). Our analysis of gene expression (GE) in 557 TNBCs from 21 public datasets identified a six-metagene signature (167 genes) in which the metagenes were enriched in different gene ontologies. The gene clusters were named as follows: Immunity1, Immunity2, Proliferation/DNA damage, AR-like, Matrix/Invasion1 and Matrix2 clusters respectively. This signature was particularly robust for the identification of TNBC subtypes across many datasets (n = 1,125 samples), despite technology differences (Affymetrix© A, Plus2 and Illumina©). Weak Immunity two metagene expression was associated with a poor prognosis (disease-specific survival; HR = 2.68 [1.59-4.52], p = 0.0002). The six-metagene signature (167 genes) was validated over 1,125 TNBC samples. The Immunity two metagene had strong prognostic value. These findings open up interesting possibilities for the development of new therapeutic interventions.

Influence of Androgen Receptor Expression on the Survival Outcomes in Breast Cancer: A Meta-Analysis

PURPOSE

Despite the fact that the androgen receptor (AR) is known to be involved in the pathogenesis of breast cancer, its prognostic effect remains controversial. In this meta-analysis, we explored AR expression and its impact on survival outcomes in breast cancer.

METHODS

We searched PubMed, EMBASE, Cochrane Library, ScienceDirect, SpringerLink, and Ovid databases and references of articles to identify studies reporting data until December 2013. Disease-free survival (DFS) and overall survival (OS) were analyzed by extracting the number of patients with recurrence and survival according to AR expression.

RESULTS

There were 16 articles that met the criteria for inclusion in our meta-analysis. DFS and OS were significantly longer in patients with AR expression compared with patients without AR expression (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.40-0.90; OR, 0.53; 95% CI, 0.38-0.73, respectively). In addition, hormone receptor (HR) positive patients had a longer DFS when AR was also expressed (OR, 0.63; 95% CI, 0.41-0.98). For patients with triple negative breast cancer (TNBC), AR expression was also associated with longer DFS and OS (OR, 0.44, 95% CI, 0.26-0.75; OR, 0.26, 95% CI, 0.12-0.55, respectively). Furthermore, AR expression was associated with a longer DFS and OS in women (OR, 0.42, 95% CI, 0.27-0.64; OR, 0.47, 95% CI, 0.38-0.59, respectively). However, in men, AR expression was associated with a worse DFS (OR, 6.00; 95% CI, 1.46-24.73).

CONCLUSION

Expression of AR in breast cancer might be associated with better survival outcomes, especially in patients with HR-positive tumors and TNBC, and women. Based on this meta-analysis, we propose that AR expression might be related to prognostic features and contribute to clinical outcomes.

Multiple molecular subtypes of triple-negative breast cancer critically rely on androgen receptor and respond to enzalutamide in vivo

Triple-negative breast cancer (TNBC) has the lowest 5-year survival rate of invasive breast carcinomas, and currently there are no approved targeted therapies for this aggressive form of the disease. The androgen receptor (AR) is expressed in up to one third of TNBC and we find that all AR(+) TNBC primary tumors tested display nuclear localization of AR, indicative of transcriptionally active receptors. While AR is most abundant in the "luminal AR (LAR)" molecular subtype of TNBC, here, for the first time, we use both the new-generation anti-androgen enzalutamide and AR knockdown to demonstrate that the other non-LAR molecular subtypes of TNBC are critically dependent on AR protein. Indeed, AR inhibition significantly reduces baseline proliferation, anchorage-independent growth, migration, and invasion and increases apoptosis in four TNBC lines (SUM159PT, HCC1806, BT549, and MDA-MB-231), representing three non-LAR TNBC molecular subtypes (mesenchymal-like, mesenchymal stem-like, and basal-like 2). In vivo, enzalutamide significantly decreases viability of SUM159PT and HCC1806 xenografts. Furthermore, mechanistic analysis reveals that AR activation upregulates secretion of the EGFR ligand amphiregulin (AREG), an effect abrogated by enzalutamide in vitro and in vivo. Exogenous AREG partially rescues the effects of AR knockdown on proliferation, migration, and invasion, demonstrating that upregulation of AREG is one mechanism by which AR influences tumorigenicity. Together, our findings indicate that non-LAR subtypes of TNBC are AR dependent and, moreover, that enzalutamide is a promising targeted therapy for multiple molecular subtypes of AR(+) TNBC.

Androgen receptor, EGFR, and BRCA1 as biomarkers in triple-negative breast cancer: a meta-analysis

OBJECTIVE

More and more evidences demonstrate that androgen receptor (AR), epidermal growth factor receptor (EGFR), and breast cancer susceptibility gene 1 (BRCA1) have unique clinical implications for targeted therapy or prognosis in triple-negative breast cancer (TNBC). Therefore, we conducted a meta-analysis to summarize the possible associations.

METHODS

We retrieved published articles about AR, EGFR, and BRCA1 in TNBC from PubMed and EMBASE. The analysis was performed with Rev-Man 5.2 software.

RESULTS

A total of 38 articles were eligible for the meta-analysis. Our study showed that the expression level of EGFR (OR = 6.88, P < 0.00001) and the prevalence of BRCA1 mutation (RR = 5.26, P < 0.00001) were higher in TNBC than non-TNBC. In contrast, the expression level of AR was lower in TNBC than non-TNBC (OR = 0.07, P < 0.00001). In the subgroup related to EGFR expression, the level of EGFR expression was significantly increased in Asians (OR = 9.60) compared with Caucasians (OR = 5.53) for TNBC patients. Additionally, the prevalence of BRCA1 mutation in Asians (RR = 5.43, P < 0.00001) was higher than that in Caucasians (RR = 5.16, P < 0.00001).

CONCLUSIONS

The distinct expression of AR and EGFR and the prevalence of BRCA1 mutation indicated that AR, EGFR, and BRCA1 might be unique biomarkers for targeted therapy and prognosis in TNBC.

Androgen receptor expression predicts decreased survival in early stage triple-negative breast cancer

BACKGROUND

A subset of triple-negative breast cancer (TNBC) has been reported to express androgen receptor (AR); however, the clinical significance of AR expression in TNBC is unclear.

METHODS

We examined immunohistochemical expression of AR in a large cohort of TNBC cases and correlated its expression with clinicopathologic features and clinical outcome.

RESULTS

AR expression was found in 17.7% (87/492) of TNBCs. Positive expression of AR showed significant correlation with older age (p < 0.001), apocrine histology (p = 0.001), and lower histologic grade (p < 0.001). AR was a poor prognostic marker for overall survival (OS) in univariate (p = 0.026) and multivariate (p = 0.008) analyses. In the lymph node-negative (n = 316) subgroup, AR expression was a significant predictor of worse OS and disease-free survival (DFS) in both univariate (p = 0.028 and 0.011) and multivariate (p = 0.024 and 0.01, respectively) analyses. AR expression also was a prognostic factor in pT1 subgroup (OS, p = 0.007; DFS, p = 0.01); however, its prognostic value was not observed in TNBC patients with lymph node metastasis or tumor size larger than pT1.

CONCLUSIONS

AR-expressing TNBCs represent a distinct breast cancer subgroup with adverse clinical outcome and AR blockade could be a potential endocrine therapy for these TNBC patients. Evaluation of AR status may provide additional information on prognosis and treatment in patients with TNBC.

Complexities of androgen receptor signalling in breast cancer

While the clinical benefit of androgen-based therapeutics in breast cancer has been known since the 1940s, we have only recently begun to fully understand the mechanisms of androgen action in breast cancer. Androgen signalling pathways can have either beneficial or deleterious effects in breast cancer depending on the breast cancer subtype and intracellular context. This review discusses our current knowledge of androgen signalling in breast cancer, including the relationship between serum androgens and breast cancer risk, the prognostic significance of androgen receptor (AR) expression in different breast cancer subtypes and the downstream molecular pathways mediating androgen action in breast cancer cells. Intracrine androgen metabolism has also been discussed and proposed as a potential mechanism that may explain some of the reported differences regarding dichotomous androgen actions in breast cancers. A better understanding of AR signalling in this disease is critical given the current resurgence in interest in utilising contemporary AR-directed therapies for breast cancer and the need for biomarkers that will accurately predict clinical response.

Androgen receptor expression in early triple-negative breast cancer: clinical significance and prognostic associations

BACKGROUND

Triple-negative breast cancers (TNBC) are characterized by aggressive tumour biology resulting in a poor prognosis. Androgen receptor (AR) is one of newly emerging biomarker in TNBC. In recent years, ARs have been demonstrated to play an important role in the genesis and in the development of breast cancer, although their prognostic role is still debated. In the present study, we explored the correlation of AR expression with clinical, pathological and molecular features and its impact on prognosis in early TNBC.

PATIENTS AND METHODS

ARs were considered positive in case of tumors with >10% nuclear-stained. Survival distribution was estimated by the Kaplan Meier method. The univariate and multivariate analyses were performed. The difference among variables were calculated by chi-square test.

RESULTS

81 TNBC patients diagnosed between January 2006 and December 2011 were included in the analysis. Slides were stained immunohistochemically for estrogen and progesterone receptors, HER-2, Ki-67, ALDH1, e-cadherin and AR. Of the 81 TNBC samples, 18.8% showed positive immunostaining for AR, 23.5% and 44.4% of patients were negative for e-cadherin and ALDH1, respectively. Positive AR immunostaining was inversely correlated with a higher Ki-67 (p < 0.0001) and a lympho-vascular invasion (p = 0.01), but no other variables. Univariate survival analysis revealed that AR expression was not associated with disease-free survival (p = 0.72) or overall survival (p = 0.93).

CONCLUSIONS

The expression of AR is associated with some biological features of TNBC, such as Ki-67 and lympho-vascular invasion; nevertheless the prognostic significance of AR was not documented in our analysis. However, since ARs are expressed in a significant number of TNBC, prospective studies in order to determine the biological mechanisms and their potential role as novel treatment target.

Revising the role of the androgen receptor in breast cancer

Breast cancer (BC) is traditionally viewed as an oestrogen-dependent disease in which the androgen receptor (AR) is inhibitory, counteracting the oncogenic activity of oestrogen receptor α (ERα (ESR1)). Most probably as a result of this crosstalk, the AR has prognostic value in ER-positive disease, with AR positivity reported to correlate with a better prognosis. Activation of the AR pathway has been previously used as a therapeutic strategy to treat BC, but its usage declined following the introduction of the anti-oestrogen tamoxifen. More recently, it has been demonstrated that a subset of triple-negative BCs (molecular apocrine) are dependent upon androgen signalling for growth and therapies that inhibit androgen signalling, currently used for the treatment of prostate cancer, e.g. the antiandrogen bicalutamide and the CYP17 inhibitor abiraterone acetate are undergoing clinical trials to investigate their efficacy in this BC subtype. This review summarises the current knowledge of AR activity in BC.

Androgenic pathways in the progression of triple-negative breast carcinoma: a comparison between aggressive and non-aggressive subtypes

One of the active intracellular pathways/networks in triple-negative breast carcinoma (TNBC) is that of the androgen receptor (AR). In this study, we examined AR and androgen-metabolising enzyme immunoreactivity in subcategories of TNBC to further elucidate the roles of androgenic pathways in TNBC. We utilised formalin-fixed paraffin-embedded breast cancer samples from ductal carcinoma in situ (DCIS) and invasive ductal carcinoma patient cohorts. We then used immunohistochemistry to classify these samples into basal-like and non-basal samples and to assess interactions between AR, androgen-metabolising enzymes and proliferation. To further substantiate our hypothesis and provide mechanistic insights, we also looked at the expression and regulation of these factors in publically available microarray data and in a panel of TNBC AR-positive cell lines. DCIS was associated with higher levels of AR and enzymes (p < 0.02), although a similar difference was not noticed in basal and non-basal samples. AR and enzymes were correlated in all states. In TNBC cell lines (MDA-MD-453, MFM-223 and SUM185-PE), we found that DHT treatment up-regulated 5αR1 and 17βHSD5 suggesting a mechanistic explanation for the correlations observed in the histological samples. Publicly available microarray data in TNBC cases suggested similar patterns to those observed in histological samples. In the majority of settings, including publically available microarray data, an inverse association between AR and proliferation was detected. These findings suggest that decreases in AR and androgen-metabolising enzymes may be involved in the increased biological aggressiveness in TNBC development.

The androgen receptor as a surrogate marker for molecular apocrine breast cancer subtyping

The Androgen Receptor (AR) is a potential prognostic marker and therapeutic target in breast cancer. We evaluated AR protein expression in high-risk breast cancer treated in the adjuvant setting. Tumors were subtyped into luminal (ER+/PgR±/AR±), molecular apocrine (MAC, [ER-/PgR-/AR+]) and hormone receptor negative carcinomas (HR-negative, [ER-/PgR-/AR-]). Subtyping was evaluated with respect to prognosis and to taxane therapy. High histologic grade (p < 0.001) and increased proliferation (p = 0.001) more often appeared in MAC and HR-negative than in luminal tumors. Patients with MAC had outcome comparable to the luminal group, while patients with HR-negative disease had increased risk for relapse and death. MAC outcome was favorable upon taxane-containing treatment; this remained significant upon multivariate analysis for overall survival (HR 0.31, 95%CI 0.13-0.74, interaction p = 0.035) and as a trend for time to relapse (p = 0.15). In conclusion, AR-related subtyping of breast cancer may be prognostic and serve for selecting optimal treatment combinations.

The impact of androgen receptor expression on breast cancer survival: a retrospective study and meta-analysis

Recent studies have highlighted the role of androgen receptor (AR) as a prognostic biomarker of breast cancer. However, its predictive role in disease free survival (DFS) and overall survival (OS) still remains inconclusive. The present study aimed to retrospectively investigate the association between AR and survival outcomes in breast cancer and also identify this association by a meta-analysis of published researches. Clinical data from 109 patients with breast cancer, who underwent surgery at Ruijin Hospital, Shanghai, were retrospectively analyzed for immunohistochemical AR expression measured by tissue microarray. For meta-analysis, articles available in Pubmed on the relationship between AR and breast cancer outcomes were included. Data obtained from both were combined and analyzed. Women with AR positive tumors in the retrospective study had a significantly better DFS (HR 0.24, 95% CI 0.07-0.88) and OS (HR 0.19, 95% CI 0.04-0.85) than women with AR negative ones. Meta-analysis showed that AR expression in breast tumors was an indicator of better DFS (HR 0.52, 95% CI 0.43-0.64). In subgroup analysis, AR could predict DFS outcome in estrogen receptor (ER) positive (HR 0.45, 95% CI 0.34-0.59), ER negative (HR 0.42, 95% CI 0.26-0.67), and triple negative breast cancer (HR 0.40, 95% CI 0.23-0.69). Moreover, in ER positive breast cancer patients, the expression of AR could predict better OS (HR 0.39, 95% CI 0.19-0.82). The present analysis indicated that AR expression was associated with lower risk of recurrence in patients with all breast cancer types and better OS in cases with ER positive.

Androgen receptor expression and outcomes in early breast cancer: a systematic review and meta-analysis

BACKGROUND

The androgen receptor (AR) is expressed frequently in breast cancer, but its prognostic significance is unclear. Preclinical data suggest that expression of AR may modify clinical outcomes in early breast cancer with improved prognosis in estrogen receptor (ER)-positive disease and poorer prognosis in ER-negative disease.

METHODS

A systematic review of electronic databases was conducted to identify studies published between 1946 and July 2012 and to explore the association between AR expression and overall survival (OS) and disease-free survival (DFS) in women diagnosed with early breast cancer. The odds ratios (OR) for OS and DFS at 3 and 5 years were calculated and then weighted and pooled in a meta-analysis with Mantel-Haenszel random-effect modeling. All statistical tests were two-sided.

RESULTS

Nineteen studies with a total of 7693 women were included. AR expression was documented in 60.5% of patients. ER-positive tumors were more likely to express AR- than ER-negative tumors (74.8% vs 31.8%, χ(2) P < .001). Compared with tumors without AR expression, those expressing AR were associated with improved OS at both 3 and 5 years (OR = 0.47, 95% confidence interval [CI] = 0.39 to 0.58, P < .001; and OR = 0.40, 95% CI = 0.29 to 0.56, P < .001). The absolute differences in the probability of OS at 3 and 5 years were 6.7% (95% CI = 3.5% to 9.8%) and 13.5% (95% CI = 7.5% to 19.6%), respectively. Results for 3- and 5-year DFS were similar. Coexpression of the ER did not influence OS at 3 or at 5 years.

CONCLUSIONS

Expression of AR in women with breast cancer is associated with better OS and DFS irrespective of coexpression of ER.

Effect of androgens on different breast cancer cells co-cultured with or without breast adipose fibroblasts

About 70% of breast tumors express androgen receptors. In addition, there is clinical evidence suggesting that androgens can inhibit mammary epithelial proliferation. Vice versa, there is also significant evidence indicating that androgens can increase the risk of breast cancer via multiple mechanisms, e.g. direct conversion to estrogens that can bind to the estrogen receptor and thereby stimulate cell proliferation. We examined the effect of testosterone (T) and dihydroxytestosterone (DHT) on cell proliferation, pS2 and Ki-67 expression in three different breast cancer cell lines alone or in co-culture with primary human breast adipose fibroblasts (BAFs) obtained from breast cancer patients. In the co-cultures, T induced cell proliferation, pS2 and Ki-67 expression in the estrogen receptor positive (ER(+)) MCF-7 and T47D cells. This was not observed in the (ER(-)) MDA-MB-231 cells. The differences might be explained by the high expression of aromatase, which converts androgens to estrogens in BAFs followed by ER-mediated cell proliferation. In line with this absence of increased cell proliferation, pS2 and Ki-67 expression was observed in the presence of DHT, which is not a substrate for aromatase. In contrast, DHT caused a significant suppression of cell proliferation (68% and 38%), pS2 and Ki-67 expression in the (ER(+)) MCF-7 and T47D cells. More importantly, DHT decreased cell proliferation in (ER(-)) MDA-MB-231 cells by 38%. The results suggest that androgens that cannot be aromatized, like DHT, may provide a perspective for treatment of breast cancer patients, especially those with triple negative breast cancer.

Long chain fatty Acyl-CoA synthetase 4 is a biomarker for and mediator of hormone resistance in human breast cancer

The purpose of this study was to determine the role of long-chain fatty acyl-CoA synthetase 4 (ACSL4) in breast cancer. Public databases were utilized to analyze the relationship between ACSL4 mRNA expression and the presence of steroid hormone and human epidermal growth factor receptor 2 (HER2) in both breast cancer cell lines and tissue samples. In addition, cell lines were utilized to assess the consequences of either increased or decreased levels of ACSL4 expression. Proliferation, migration, anchorage-independent growth and apoptosis were used as biological end points. Effects on mRNA expression and signal transduction pathways were also monitored. A meta-analysis of public gene expression databases indicated that ACSL4 expression is positively correlated with a unique subtype of triple negative breast cancer (TNBC), characterized by the absence of androgen receptor (AR) and therefore referred to as quadruple negative breast cancer (QNBC). Results of experiments in breast cancer cell lines suggest that simultaneous expression of ACSL4 and a receptor is associated with hormone resistance. Forced expression of ACSL4 in ACSL4-negative, estrogen receptor α (ER)-positive MCF-7 cells resulted in increased growth, invasion and anchorage independent growth, as well as a loss of dependence on estrogen that was accompanied by a reduction in the levels of steroid hormone receptors. Sensitivity to tamoxifen, triacsin C and etoposide was also attenuated. Similarly, when HER2-positive, ACSL4-negative, SKBr3 breast cancer cells were induced to express ACSL4, the proliferation rate increased and the apoptotic effect of lapatinib was reduced. The growth stimulatory effect of ACSL4 expression was also observed in vivo in nude mice when MCF-7 control and ACSL4-expressing cells were utilized to induce tumors. Our data strongly suggest that ACSL4 can serve as both a biomarker for, and mediator of, an aggressive breast cancer phenotype.

Androgen receptor-positive triple negative breast cancer: a unique breast cancer subtype

BACKGROUND

The significance of androgen receptor (AR) expression in triple-negative breast cancer (TNBC) is unclear, and published studies so far have been inconclusive.

METHODS

A tissue microarray was constructed using tissue obtained from 119 patients with primary TNBC and stained for AR expression. Other tissue types obtained included recurrent TNBC, normal breast tissue, adjacent ductal carcinoma-in situ (DCIS), lymph node (LN) and distant metastases. Positive AR expression was defined as ≥10% nuclear staining.

RESULTS

Epithelial tissue was present and evaluable in 94 TNBC patients with a total of 177 tissue cores. AR expression in TNBC was 22 of 94 (23%). AR expression was higher in normal breast tissue (88%) and adjacent DCIS (73% overall). All LN metastases from AR-positive TNBC patients were also AR positive; in addition, no AR-negative TNBC patient had AR-positive LNs. AR expression was associated with older patient age (63 vs. 57 years, respectively, p = 0.051) and LN metastases (p = 0.033). Locoregional recurrence and overall/disease-specific survival were similar between AR-positive and AR-negative patients, although AR-positive patients had more advanced disease. On multivariate analysis, the presence of LN metastases was associated with poorer recurrence-free survival in AR-positive patients (hazard ratio, 4.34) (p = 0.031).

CONCLUSIONS

The AR is expressed in normal breast tissue, and expression decreases with advancement to DCIS and invasive cancer. AR-positive TNBC was more common in older patients and had a higher propensity for LN metastases. AR-positive TNBC may represent a breast cancer subtype with unique features that may be amenable to treatment with alternative targeted therapies.

The Role of the Androgen Receptor in Triple-Negative Breast Cancer

Greater than 70% of human breast cancers express the androgen receptor (AR). Emerging preclinical and clinical data suggest that AR may play a role in breast cancer pathogenesis and may serve as a therapeutic target in certain more difficult-to-treat breast cancer subtypes, such as triple-negative breast cancer. Although this is an area of active investigation, the clinical significance of this hormone receptor as a prognostic/predictive marker and its functional role in tumorigenesis is unclear. This review provides an update on the advances made in the last several years regarding the role of AR as a prognostic/predictive biomarker in breast cancer, the underlying biology of AR signaling in breast cancer development and the available clinical data for the use of androgen inhibition in the treatment of AR+ triple-negative breast cancer.

Molecular apocrine breast cancers are aggressive estrogen receptor negative tumors overexpressing either HER2 or GCDFP15

Introduction

Molecular apocrine (MA) tumors are estrogen receptor (ER) negative breast cancers characterized by androgen receptor (AR) expression. We analyzed a group of 58 transcriptionally defined MA tumors and proposed a new tool to identify these tumors.

Methods

We performed quantitative reverse transcription PCR (qRT-PCR) for ESR1, AR, FOXA1 and AR-related genes, and immunohistochemistry (IHC) for ER, PR, Human Epidermal Growth Factor Receptor 2 (HER2), CK5/6, CK17, EGFR, Ki67, AR, FOXA1 and GCDFP15 and we analyzed clinical features.

Results

MA tumors were all characterized by ESR1(-) AR(+) FOXA1(+) and AR-related genes positive mRNA profile. IHC staining on these tumors showed 93% ER(-), only 58% AR(+) and 90% FOXA1(+). 67% and 57% MA tumors were HER2(3+) and GCDFP15(+), respectively. Almost all MA tumors (94%) had the IHC signature HER2(3+) or GCDFP15(+) but none of the 13 control basal-like (BL) tumors did. Clinically, MA tumors were rather aggressive, with poor prognostic factors.

Conclusion

MA tumors could be better defined by their qRT-PCR-AR profile than by AR IHC. In addition, we found that HER2 or GCDFP15 protein overexpression is a sensitive and specific tool to differentiate MA from BL in the context of ER negative tumors. A composite molecular and IHC signature could, therefore, help to identify MA tumors in daily practice.

Expression of androgen receptors in triple negative breast carcinomas

Triple negative breast cancer (TNBC) consists of a group of tumors with poor prognosis, owing to aggressive tumor biology and lack of targeted therapy. The aim of this study was to assess the immunostaining for androgen receptors (ARs) in the group of TNBC, in addition to basal-like (BL) immunophenotype, BL morphology and conventional clinicopathological factors and to demonstrate its prognostic relevance in this group of tumors. The study included 83 patients. Slides were stained immunohistochemically for estrogen and progesterone receptors, HER2, CK5/6, CK14, EGFR, Ki-67 and AR. Of the 83 TNBC samples, 32.5% showed positive immunostaining for AR, 66.3% had BL immunophenotype, and 48.2% had BL morphology. Positive AR immunostaining was inversely correlated with higher clinical stage, higher mitotic score, higher histological grade and higher proliferation index measured by Ki-67. Significantly more AR negative tumors were observed among the tumors with BL immunophenotype and BL morphology. There was no significant association between positive AR immunostaining and disease free survival or overall survival. More than one third of TNBC were AR-positive, and this represents a potential opportunity for novel targeted treatment in the group of breast tumors for which therapeutic options are currently limited.

Androgenic pathway in triple negative invasive ductal tumors: its correlation with tumor cell proliferation

Triple negative breast cancer (TNBC) is defined by estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 negativity. Patients with TNBC frequently undergo an aggressive clinical course due to the unavailability of specific targeted therapies. Androgen receptor (AR) was reported to be expressed in up to 60% of TNBC cases but there have been controversies as to the roles of androgen signaling through AR in TNBC. Therefore, in this study, we analyzed the status of AR in combination with androgen synthesizing enzymes (5α-reductase type 1 (5αR1) and 17β-hydroxysteroid dehydrogenase type 5 (17βHSD5)] in order to further understand androgenic actions in TNBC. Androgen receptor, 5αR1, and 17βHSD5 were immunolocalized in a cohort of 203 TNBC patients from Thailand and Japan. We then correlated the findings with clinicopathological characteristics (age, stage, tumor diameter, lymph node invasion, metastatic spread, Ki-67 labeling index, disease-free survival, and overall survival) of the patients. Univariate analysis revealed that AR+/enzyme+ cases were associated with a significantly lower Ki-67 labeling index than AR-/enzyme- samples. Multivariate analysis indicated the presence of significant positive correlations between AR and enzyme status in tumor cells, and between tumor diameter, lymph node invasion, and distant metastasis. Significant negative correlations were also detected between Ki-67 labeling index and AR status (P = 0.04) or 5αR1 (P < 0.001). Cox proportional hazards analysis showed that Ki-67 labeling index and stage were the only factors predicting disease-free and overall survival of the patients, although univariate Kaplan-Meier analysis revealed AR/5αR1 negativity suggested a more adverse clinical course up to 80 months after surgery. These results suggest that the presence of androgen synthesizing pathways in addition to AR expression in tumor cells could confer a better clinical outcome through suppression of cell proliferation.

Androgen receptor in triple negative breast cancer

The clinical management of triple negative breast cancer (TNBC) is challenging due to the relatively aggressive biological behaviour and paucity of specific targeted therapy. A subset of TNBC patients has been reported to express androgen receptor (AR) in carcinoma cells and the manipulation of androgen signalling or AR targeted therapies have been proposed. However, the biological significance of AR in TNBC has remained relatively unknown. Therefore, this review aims to summarise the reported studies assessing the rates of AR positivity in TNBC patients and androgenic effects in TNBC cell lines. The rates of AR positivity among TNBC cases varied depending on the study population (0-53% of all TNBC patients). This difference among the reported studies may be largely due to the methodological differences of analysing AR. While the majority of cell line studies suggest that androgen increase proliferation and preliminary clinical studies suggest that AR antagonists improve the prognosis of AR positive TNBC patients, cell line transfection experiments and survival analyses of histological samples suggest that the presence of AR in tumour is either benign or predicts better survival. Therefore further translational investigations regarding the mechanisms of androgen action in TNBC are required to explain this discrepancy between clinical and basic studies.

Does Androgen Receptor Have a Prognostic Role in Patients with Estrogen/Progesterone-Negative and c-erbB-2-Positive Breast Cancer?

Recently, it has been shown that androgen and androgen receptor (AR) also have an important role in the pathogenesis and outcome of breast cancer. However, their significance in different subtypes of breast cancer is still under investigation. The aim of this study was to study the effects of AR on clinicopathological features and prognosis in patients with estrogen and progesterone receptor (ER/PR)-negative, HER2-positive breast cancer. Tumor paraffin-embedded blocks from archives were used for AR study. Data of patients with ER/PR-negative and HER2-positive breast cancer diagnosed at our institute between 1999 and 2010 were recorded and analyzed retrospectively. We studied 36 patients with ER/PR-negative and HER2-positive breast cancer for AR status. Sixteen of them (44.4%) showed AR positivity. The median age was 47 and 56 years for AR-negative and -positive patients, respectively ( P = 0.03). The number of postmenopausal patients was higher in the AR-positive than -negative group (56 vs 30%) ( P = 0.01). Other demographic data were similar in both group. Histopathological parameters and tumor and nodal stages were similar in both groups. Trastuzumab treatment was more frequently given to AR-positive than -negative patients (94 vs 44%) ( P = 0.01). Median follow-up was 47.1 and 34.7 months in AR-negative and -positive groups, respectively ( P = 0.03). Relapse occurred in six and four patients in AR-negative and -positive groups. Median progression-free survival (PFS) was similar in both groups (15.7 and 19.6 months in AR-negative and -positive patients, respectively; P = 0.56). Two patients died at 23.4 and 46 months of follow-up in the AR-negative group. There were no deaths in the AR-positive group. Overall survival analyses were not done as a result of an unmet number of events. Median PFS was similar in AR-positive and -negative in that group of patients with ER/PR-negative and HER2-positive breast cancer. However AR-positive patients were more frequently postmenopausal, older, and positive for lymphovascular space invasion. More frequently applied trastuzumab in the AR-positive group might have an effect on the similarity of PFS between the two groups. Studies with higher numbers in this subset of patients with breast cancer will give more robust data.

Recent developments in antiandrogens and selective androgen receptor modulators

The androgens testosterone and dihydrotestosterone play an essential role in the development and maintenance of primary and secondary male characteristics. Androgens bind to a specific androgen receptor (AR), a ligand-dependent transcription factor which controls the expression of a large number of downstream target genes. The AR is an essential player in early and late prostate cancer, and may also be involved in some forms of breast cancer. It also represents a drug target for the treatment of hypogonadism. Recent studies furthermore indicate that targeting the AR in pathologies such as frailty syndrome, cachexia or polycystic ovary syndrome may have clinical benefit. Numerous AR ligands with very different pharmacological properties have been identified in the last 40 years and helped to treat several of these diseases. However, progress still needs to be made in order to find compounds with an improved profile with regard to efficacy, differentiation and side-effects. This will only be achieved through a better understanding of the mechanisms involved in normal and aberrant AR signaling.

Occult breast cancer presenting as metastatic adenocarcinoma of unknown primary: clinical presentation, immunohistochemistry, and molecular analysis

We report a rare presentation of a 66-year-old female with diffuse metastatic adenocarcinoma of unknown primary involving liver, lymphatic system and bone metastases. The neoplastic cells were positive for CK7 and OC125, while negative for CK20, thyroid transcription factor 1, CDX2, BRST-2, chromogranin, synaptophysin, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2/neu). Fluorescence in situ hybridization showed no amplification of the HER2/neu gene. Molecular profiling reported a breast cancer origin with a very high confidence score of 98%. The absence of immunohistochemistry staining for ER, PR, and HER2/neu further classified her cancer as triple-negative breast cancer. Additional studies revealed high expression levels of topoisomerase (Topo) I, androgen receptor, and ribonucleoside-diphosphate reductase large subunit; the results were negative for thymidylate synthase, Topo II-a and O6-methylguanine-DNA methyltransferase. The patient was initially treated with a combination regimen of cisplatin and etoposide, and she experienced a rapid resolution of cancer-related symptoms. Unfortunately, her therapy was complicated by a cerebrovascular accident (CVA), which was thought to be related to cisplatin and high serum mucin. After recovery from the CVA, the patient was successfully treated with second-line chemotherapy based on her tumor expression profile. We highlight the role of molecular profiling in the diagnosis and management of this patient and the implication of personalized chemotherapy in this challenging disease.

Clinical importance of androgen receptor in breast cancer patients treated with adjuvant tamoxifen monotherapy

BACKGROUND: Despite many studies, the clinicopathological importance of the androgen receptor (AR) in breast cancer is not well established, and its significance as an independent predictor of clinical outcome is controversial. A large and systematic study is needed to address these issues. The aim of the present study was to elucidate whether AR has independent clinical value, examining its importance in a large and well-predefined patient group with a long follow-up period and complete clinicopathological data. METHODS: Archival materials of 403 invasive breast cancers from women treated with adjuvant tamoxifen monotherapy (median follow-up period 11.0 years) were subjected to immunohistochemical study using anti-AR monoclonal antibody. AR expression was compared with established clinicopathological factors, estrogen receptor (ER)-β expression, and clinical outcome. RESULTS: AR positivity was correlated with ER-α positivity, progesterone receptor positivity, ER-β positivity, and a lower nuclear grade. Patients with AR-positive carcinomas exhibited a significantly better clinical outcome than those with AR-negative carcinomas (P = 0.0165 for disease-free survival, P = 0.0344 for overall survival). Multivariate analysis did not yield significant differences in clinical outcome according to the AR status, whereas the ER-β status showed significant differences in multivariate analysis. CONCLUSIONS: Although, and in agreement with previous reports, AR positivity correlated with some established favorable prognostic factors and with ER-β positivity, AR was not an independent predictor of clinical outcome. Controversy regarding the value of AR as an independent predictor of clinical outcome may at least partly reflect the relatively limited power of AR in breast cancer.

Androgens and breast cancer

The role of androgens on breast cancer development and progression has not been fully elucidated. Several in vivo and in vitro studies demonstrate that androgens have an inhibitory effect on the mammary epithelium, whereas the majority of epidemiological studies report a positive association between high androgen levels and risk of breast cancer. Expression of the androgen receptor is a positive prognostic factor. Understanding the role of androgens in breast carcinogenesis is important because many women use testosterone replacement for the alleviation of symptoms brought on by menopause, in particular high-risk women who undergo surgical menopause at an early age. We overview the literature examining a role of androgens in the etiology of breast cancer.

Androgen receptor expression in primary breast cancer and its predictive and prognostic value in patients treated with neoadjuvant chemotherapy

The androgen receptor (AR) has been shown to be of potential prognostic importance in retrospective cohorts. We evaluated immunohistochemical AR expression on a tissue microarray of 673 core biopsies from primary breast cancer patients treated with neoadjuvant docetaxel/doxorubicin/cyclophosphamide (TAC) chemotherapy in the prospective GeparTrio phase-III trial. AR was detected in 53.2% of tumours. Lowest AR expression was detected in triple-negative breast cancers (TNBC) with 21.2%. Highest AR expression was observed in Luminal A-like tumours with 67%. In AR-positive tumours, pathological complete response (pCR) rate was 12.8% compared to 25.4% in AR-negative tumours (P < 0.0001). In multivariate analysis, AR independently predicted pCR (OR 1.86; 95% CI [1.16-2.79] P = 0.0086). Overall patients with an AR-positive tumour had a significant better disease-free (DFS) (AR-positive 78.9% vs. AR-negative 72.5%; log-rank P = 0.0329) and overall survival (OS) (88.8% vs. 82.7%; log-rank P = 0.0234) than those with AR-negative tumours. Stratified analysis revealed that in the TNBC subgroup, but not in the other subgroups defined by ER, PgR and HER2, AR expression predicted a better DFS (AR-positive 85.7% vs. AR-negative 65.5% log-rank P = 0.0544) and OS (95.2% vs. 76.2%; log-rank P = 0.0355). Within the non-pCR subgroup, AR positivity selected a group with a significant better DFS (P = 0.045) and OS (0.021) but not within the pCR group. Patients with an AR-negative tumour have a higher chance of achieving a pCR than those with an AR-positive one. But, patients with AR-positive tumours have a better survival especially if they did not achieve a pCR.

'Triple negative' epithelial ovarian cancer and pathologic markers for prognosis

PURPOSE OF REVIEW

To summarize the recent evidence for 'triple negative' epithelial ovarian cancer (TNEOC), characterized by lack of expression of estrogen receptor, progesterone receptor and human epidermal growth factor receptor type 2 (HER2), and to discuss its potential pathologic markers for prognosis and targeted therapy.

RECENT FINDINGS

'Triple negative' phenotype is traditionally referred to as a specific subtype of breast cancer negative for estrogen receptor, progesterone receptor and HER2 expression. Recent studies have shown that such 'triple negative' phenotype also exists in ovarian and endometrial cancer. TNEOC accounts for about 15% of epithelial ovarian carcinoma. This specific subtype tends to exhibit more aggressive characteristics and a worse prognosis. The molecular features of TNEOC are similar to those of 'triple negative' breast cancer (TNBC), a widely studied histological subtype. Recently, a panel of specific pathologic biomarkers has been identified in TNBC. Currently, phase I and phase II trials to examine the safety and efficacy of a poly (ADP-ribose) polymerase inhibitor (olaparib) and angiogenesis inhibitors (sunitinib and bevacizumab) in TNBC are ongoing. These TNBC-associated pathologic markers could be used to screen for novel prognostic factors and therapeutic targets in TNEOC.

SUMMARY

'Triple negative' phenotype has important implications for clinical management of patients with ovarian cancer.

Androgen receptor expression and breast cancer survival in postmenopausal women

PURPOSE

Androgen receptor (AR) is commonly expressed in breast cancers. However, the association between tumor AR status and breast cancer survival is uncertain. Hence, we examined the association between AR status and breast cancer survival in the Nurses' Health Study (NHS).

EXPERIMENTAL DESIGN

It was a prospective study of postmenopausal women enrolled in the Nurses' Health Study with stage I to III breast cancer diagnosed between 1976 and 1997 and followed from the date of diagnosis until January 1, 2008 or death. Analyses were conducted using Kaplan-Meier methods and Cox proportional hazard models, to determine the association of AR status with survival outcomes adjusting for covariates.

RESULTS

Among 1467 breast cancers, 78.7% were AR-positive (AR+). Among 1,164 estrogen receptor (ER)-positive cases, 88.0% were AR+. AR positivity was associated with a significant reduction in breast cancer mortality (HR, 0.68; 95% CI, 0.47-0.99) and overall mortality (HR, 0.70; 95% CI, 0.53-0.91) after adjustment for covariates. In contrast, among women with ER-negative tumors (303 cases), 42.9% were AR+. There was a nonsignificant association between AR status and breast cancer death (HR, 1.59; 95% CI, 0.94-2.68).

CONCLUSIONS

The association of AR status and breast cancer survival is dependent on ER status. In particular, AR expression was associated with a more favorable prognosis among women with ER-positive tumors. Thus, determination of AR status may provide additional information on prognosis for postmenopausal women with breast cancer, and provide novel opportunities for targeted therapy.