
==== Front
Rom J Morphol Embryol
Rom J Morphol Embryol
RJME
Romanian Journal of Morphology and Embryology
1220-0522
2066-8279
Academy of Medical Sciences, Romanian Academy Publishing House, Bucharest

39020535
650224209216
10.47162/RJME.65.2.07
Original Paper
Triple-negative breast cancer: from classical clinicopathological features to androgen receptor profile
Prutianu Iulian 12
Giuşcă Simona Eliza 1
Gafton Bogdan 34
Chifu Mariana Bianca 1
Terinte Cristina 5
Antonescu Alexandra 34
Popovici Larisa 4
Căruntu Irina-Draga 16
1 Department of Morpho-Functional Sciences I, Grigore T. Popa University of Medicine and Pharmacy, Iaşi, Romania
2 Department of Oncology, Neolife Medical Center, Iaşi, Romania
3 IIIrd Medical Department, Grigore T. Popa University of Medicine and Pharmacy, Iaşi, Romania
4 Department of Oncology, Regional Institute of Oncology, Iaşi, Romania
5 Department of Pathology, Regional Institute of Oncology, Iaşi, Romania
6 Academy of Medical Sciences, Bucharest, Romania
Corresponding Author: Simona Eliza Giuşcă, Associate Professor, MD, PhD Department of Morpho-Functional Sciences I Grigore T. Popa University of Medicine and Pharmacy 16 University Street 700115 Iaşi Romania + 40232–301 615 simonaelizagiusca@gmail.com
Corresponding Author: Mariana Bianca Chifu, Assistant Professor, MD, PhD Department of Morpho-Functional Sciences I Grigore T. Popa University of Medicine and Pharmacy 16 University Street 700115 Iaşi Romania + 40232–301 615 bianca.manole@ymail.com
Apr-Jun 2024
30 6 2024
65 2 209216
15 4 2024
28 5 2024
Copyright © 2024, Academy of Medical Sciences, Romanian Academy Publishing House, Bucharest
2024
https://creativecommons.org/licenses/by-nc-sa/4.0/ This is an open-access article distributed under the terms of a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International Public License, which permits unrestricted use, adaptation, distribution and reproduction in any medium, non-commercially, provided the new creations are licensed under identical terms as the original work and the original work is properly cited.
Triple-negative breast cancer (BC) represents an extensively analyzed entity to establish the overall framework of clinicopathological characteristics, with an impact on defining prognostic and predictive factors. The relationship between triple-negative BC and androgen receptor (AR) is far from being clarified. We aimed to evaluate the classical clinicopathological spectrum that characterized a triple-negative BC, focusing on AR expression. The study group comprised 124 cases of triple-negative BC. The main clinicopathological parameters were extracted from medical records. The immunohistochemical (IHC) exam was run using the following antibodies: anti-estrogen receptor (ER), anti-progesterone receptor (PR), anti-human epidermal growth factor receptor (HER2/neu), anti-Ki67 and anti-AR. AR immunoexpression was assessed as absent (completely negative) or present (unrelated to percentages and intensity). Data were statistically analyzed. AR expression was positive in 78 (63%) cases and negative in 46 (37%) cases. Among the study group, 28 cases exhibited an AR percentage ranging from 1% to 10%, 15 cases showed a percentage between 11% and 50%, while 12 cases had AR values between 51% and 75% and 23 cases fell within the AR range of 76% to 100%. No significant differences between AR immunoexpression (negative versus positive), clinicopathological characteristics and survival parameters were found. Statistically significant differences were registered between histological type, tumor stage, distant metastasis, tumor-infiltrating lymphocytes (TILs), treatment and residual cancer burden (RCB), and survival parameters. Thus, our results sustain that AR does not affect the biological behavior of triple-negative BC.

triple-negative breast cancer
androgen receptor
prognostic factor
==== Body
pmcIntroduction

Breast cancer (BC) is the dominant form of cancer among women globally, ranking second in incidence after lung cancer and fourth in mortality after colorectal, liver and lung cancer [1, 2, 3].

The concept of molecular classification in BC proposed in 2000 has as its scientific basis the identification of biological forms of cancer that share common characteristics both in terms of molecular profile and therapeutic approach [4]. Four defined molecular classes, known as luminal A, luminal B, human epidermal growth factor receptor (HER2/neu), and triple negative were confirmed in 2012 by the Cancer Genome Atlas program [5]. Currently, the BC molecular subtypes guide the therapeutic options.

The triple-negative BC represents about 10–15% of all BC cases, being defined by the lack of hormonal receptors – namely estrogen receptor (ER) and progesterone receptor (PR) – and HER2/neu, together with a high proliferation index, giving it an aggressive pattern. Patients have a 66% higher risk of presenting with high-grade tumors at diagnosis [6].

Subclassifications based on trait uniqueness analyzed by immunohistochemical (IHC) profiling and genomic ribonucleic acid (RNA) or deoxyribonucleic acid (DNA) sequencing have been proposed for triple-negative BC [7, 8, 9, 10]. The identified entities are defined as basal-like 1 (BL1) type, basal-like 2 (BL2) type, mesenchymal (M) type, mesenchymal stem-like (MSL) type, immunomodulatory (IM) type and luminal androgen receptor (LAR) type. It is worth mentioning the report of quadruple-negative BC in which, in addition to the absence of ER, PR and HER2/neu immunoexpression, androgen receptor (AR) expression is also lost. This variant is expressed in about 10–43% of triple-negative BC [11].

The new subclassification has not yet been introduced into clinical practice [12]. However, the literature confirms that neoadjuvant therapy, including pathological complete response (pCR), is dependent on these entities [13]. The BL1 variant had the highest rate of pathological response, whereas the BL2 and LAR variants have the lowest rate [13, 14].

The relationship between triple-negative BC and AR is important for therapeutic decisions [14]. AR is predominantly expressed in LAR subtype [14]. However, the reports on AR significance as a prognostic factor are contradictory.

Aim

Within this context, our study aims to evaluate the classical clinicopathological spectrum that characterized a triple-negative BC group of patients; additionally, we focused on the AR expression along with the clinicopathological outlines, developing a correlational analysis to highlight its influence on tumor behavior.

Patients, Materials and Methods

Patients

The study group comprised 124 patients diagnosed with triple-negative BC between January 2018 and December 2022 at the Department of Pathology, Regional Institute of Oncology, Iaşi, Romania. The major selection criterion was the diagnostic classification in the triple-negative subtype based on the IHC profile: ER, PR, and HER2/neu. The main clinicopathological parameters were collected from medical records. These parameters were established in accordance with the classification of breast tumors afforded by World Health Organization (WHO) [15], and included age, histological type, histological characteristics, tumor grade, clinical and pathological tumor–node–metastasis (TNM) stage, tumor-infiltrating lymphocytes (TILs), first-line treatment, residual cancer burden (RCB), progression-free survival (PSF) and overall survival (OS). It is worth mentioning that out of a total of 124 patients, 99 (79.8%) patients underwent surgical treatment after neoadjuvant therapy. For the 25 (20.2%) cases unqualified for surgery, the microscopic exam of the surgical resection specimen could not be performed. Consequently, the assessment of the pathological characteristics, such as pTMN, lymphatic, vascular and perineural invasion, respectively, and RCB was exclusively conducted in the subgroup composed of 99 cases.

Ethical approval was granted from the Ethics Board responsible for research ethics at the Grigore T. Popa University of Medicine and Pharmacy, Iaşi, and the Regional Institute of Oncology, Iaşi, respectively.

Tissue samples and histopathological exam

Specimens were obtained through either needle core biopsy or radical mastectomy. Following collection, they underwent fixation in 10% neutral buffered formalin and were processed to obtain paraffin-embedded blocks for standard histopathological exam. Sections of 4–5 μm-thick were cut, placed on slides, deparaffinized using xylene and gradually rehydrated with ethanol in reducing concentrations, and stained with Hematoxylin–Eosin (HE).

Immunohistochemical exam

The initial IHC exam was run using the classical antibody panel for BC diagnosis, namely ER, PR, HER2/neu and Ki67. In the next stage, the IHC exam was complemented with AR expression analysis (Table 1).

Table 1 Clones, dilutions and expression for antibodies

Antibody

	Clone, source

	Dilution

	Cellular localization

	
ER

	Anti-ER (SP1) – rabbit monoclonal antibody (Roche, Basel, Switzerland)

	RTU

	Nuclear

	
PR

	Anti-PR (1E2) – rabbit monoclonal antibody (Roche, Basel, Switzerland)

	RTU

	Nuclear

	
HER2/neu

	Anti-HER2/neu (4B5) – rabbit monoclonal antibody (Roche, Basel, Switzerland)

	RTU

	Membrane

	
Ki67

	Anti-Ki67 (30-9) – rabbit monoclonal antibody (Roche, Basel, Switzerland)

	RTU

	Nuclear

	
AR

	Anti-AR (SP107) – rabbit monoclonal antibody (Thermo Fisher Scientific, Waltham, MA, USA)

	1:500

	Nuclear

	
AR: Androgen receptor; ER: Estrogen receptor; HER2/neu: Human epidermal growth factor receptor; PR: Progesterone receptor; RTU: Ready-to-use

The IHC protocol included the following steps: dewaxing in xylol, rehydration in ethanol baths with decreasing concentrations, heat-induced antigen retrieval using a target retrieval solution with pH 6 at 98°C for 20 minutes, inhibition of endogenous peroxidase activity in a solution of hydrogen peroxide, incubation with the primary antibody at room temperature for 60 minutes, and visualizations of the reaction with the appropriate detection system. The positive control consisted of positive BC tissue for ER, PR and HER2/neu, tonsil for Ki67 and prostate tissue for AR. Negative control was done by excluding the primary antibody.

Immunoexpression assessment

The Allred scoring system was applied to evaluate nuclear positivity for ER and PR [16]. The scoring method involved the proportion score (PS), graded from 0 to 5 to represent the positive tumor cell’s percentage, and intensity of staining (IS), graded from 0 to 3 to denote staining strength. PS values delineated specific ranges: 0 (0%), 1 (<1%), 2 (1–10%), 3 (11–33%), 4 (34–66%), and 5 (67–100%). IS was evaluated across a spectrum ranging from 0, indicating no detectable staining, to 3, representing the highest level of observed immunoreactivity. Total scores (TS) were calculated by summing PS and IS scores, where TS 0 and 2 were deemed negative, and TS from 3 to 8 were considered positive. Thus, TS of 0, 1 and 2 were considered as valuable for triple-negative BC diagnosis.

HER2/neu status assessment adhered to established criteria which categorized immunoreactivity into four distinct scores [17]. A score of 0 indicated either a complete absence of immunoreactivity or immunoreactivity present in less than 10% of tumor cells. Conversely, a score of 1+ signified faint weak immunoreactivity observed in more than 10% of cells, with only a portion of the membrane exhibiting positivity. For a score of 2+, either weak or moderate immunoreactivity, completely marking the membrane, was detected in over 10% of cells, or intense staining was visible in less than 30% of cells. Lastly, a score of 3+ was assigned when more than 30% of tumor cells displayed uniform membrane staining, suggestive of positivity, often characterized by a homogeneous chicken-wire pattern. Thus, score 0 and score 1+, regarded as negative immunoreaction, were considered for triple-negative BC diagnosis.

AR evaluation was assessed based on the nuclear staining on entire sections [18, 19]. The fractions of positively marked nuclei within malignant cells, varying between 1% and 100%, were evaluated, disregarding the immunostaining intensity. According to the percentage, we used four intervals, as follows: 1% to 10%, 11% to 50%, 51% to 75% and 76% to 100%. Finally, AR immunoexpression was categorized as absent (completely negative) or present (unrelated to percentages and intensity), resulting in two classes: AR absent and AR present.

Ki67 values were quantified as the percentage of nuclei exhibiting positive immunostaining throughout the tumor, with no regard to staining intensity [20]. A median score of 50% immunopositive cells served as the delineation point, distinguishing between lower expression (Ki67 score below 50%) and higher expression (Ki67 score above 50%) [20].

Statistical analysis

All obtained results were analyzed by using the facilities provided by Statistical Package for Social Sciences (SPSS) software ver. 19 (SPSS Inc., Chicago, IL, USA), running χ2 (chi-squared) and Fisher’s exact test, respectively, for nominal variable correlations, and Kaplan–Meier curves and log-rank test for survival data. The p-value less than 0.05 indicated statistical significance.

Results

Baseline clinicopathological parameters

Within the analyzed cohort, the mean age was 58.73±12.2 years; the youngest individual was 33 years old, while the oldest was 85.

For most patients, namely 109 (87.9%) cases, the established diagnosis was invasive ductal carcinoma – not otherwise specified (NOS), indicating a common form of BC. Ten (18.1%) cases presented metaplastic carcinoma, whereas the remaining five (4%) cases encompassed various other subtypes, representing less frequent histological variations within the study cohort. Figure 1A, 1B, 1C, 1D illustrates different histological types of BC.

Figure 1 Different histological subtypes of triple-negative breast carcinoma: (A) Invasive ductal carcinoma, NOS; (B) Invasive ductal carcinoma with medullary pattern; (C) Lobular carcinoma; (D) Apocrine carcinoma. HE staining: (A and C) ×200; (B and D) ×100. HE: Hematoxylin–Eosin; NOS: Not otherwise specified

Among the study group, three (2.4%) cases were categorized as G1, signifying well-differentiated tumors with a lower level of morphological abnormality, 18 (14.5%) cases were classified as G2 – moderately differentiated tumors, with a mild level of abnormality, and 103 (83.1%) cases were graded as G3, denoting poorly differentiated tumors with the highest level of abnormality and aggressiveness.

In the study group, the distribution of cases in relation to clinical tumor stage was as follows: 11 (8.9%) cases in T1 (small size tumor, with a maximum of 20 mm); 65 (52.4%) cases in T2 (tumor size more than 20 mm, with a maximum of 50 mm); 13 (10.5%) cases in T3 (tumor size more than 50 mm); 35 (28.2%) cases in T4 (any size, but extension to chest wall or skin). Additionally, the clinical node stage indicated: 32 (25.8%) cases in N0; 56 (45.2%) cases in N1; 22 (17.8%) cases in N2; 14 (11.2%) cases in N3. Based on imaging examination upon diagnosis, 99 (79.8%) cases had no clinical or imaging proof of distant metastases (M0), whereas the other 25 (20.2%) cases presented distant metastases (M1). Based on the clinical TMN, tumor staging indicated stage II as the most prevalent (48 cases – 38.7%), followed by stage III (44 cases – 35.5%) and stage IV (25 cases – 20.2%), while stage I (seven cases – 5.6%) comprises the smallest percentage within the cohort.

Histopathology established the following grouping of pathological tumor stage: 40 (32.3%) cases in pT1, 40 (32.3%) cases in pT2, seven (5.6%) cases in pT3, 12 (9.6%) cases in pT4, and no data available for 25 (20.2%) cases. In terms of pathological lymph node involvement, 52 (41.9%) cases presented N0 stage, 28 (22.6%) cases were categorized as N1, 12 (9.7%) cases were observed in N2, seven (5.6%) cases were classified as N3 category, and no data were accessible for 25 (20.2%) cases.

The evaluation of lymphatic invasion reveals 42 (33.8%) cases of cases exhibiting tumor emboli, while 57 (46%) cases showed no signs of invasion; 25 (20.2%) cases remained unspecified. Similarly, vascular invasion analysis yields further insights: positive results were obtained in 24 (19.4%) cases, contrasting with no tumor emboli in 75 (60.4%) cases, and 25 (20.2%) cases with no available data. Furthermore, perineural invasion assessment revealed nerve infiltration in 18 (14.5%) cases, 81 (65.3%) cases without nerve involvement, and 25 (20.2%) cases with unavailable information.

The diversity of TILs was evident: 72 (58%) cases exhibited low-grade TILs, reflecting a subdued immune response; in 31 (25%) cases, an intermediate-grade TILs suggested a moderate immune reaction; high-grade TILs, detected in 21 (17%) cases, signified an active immune response to the tumor.

Regarding the Ki67 expression, less than 50% of positive tumor cells was seen in 15 (12%) cases, whereas 109 (88%) cases exceeded 50%.

The RCB analysis within our study cohort showed that 12 (9.7%) cases achieved a complete response – RCB 0, 20 (16.1%) cases were classified as RCB I, 44 (35.5%) cases fell into the RCB II and 23 (18.5%) cases were categorized as RCB III; no data were accessible for 25 (20.2%) cases.

Androgen receptor assessment

The IHC analysis of AR expression indicated immunopositivity in 78 (63%) cases, while negative immunoexpression was observed in 46 (37%) cases. Among the study group, 28 cases (22.6% of total group, 35.9% of all positive cases) exhibited an AR percentage ranging from 1% to 10%, 15 cases (12.1% of total group, 19.2% of all positive cases) showed a percentage between 11% and 50%, while 12 cases (9.7% of total group, 15.4% of all positive cases) had AR values between 51% and 75% and 23 cases (18.6% of total group, 29.5% of all positive cases) fell within the AR range of 76% to 100%. Figure 2A, 2B, 2C, 2D illustrates the wide range of AR positive immunoexpression.

Figure 2 Different AR immunoexpression: (A) Percentage of positive tumor cells over 76%; (B) Percentage of positive tumor cells between 11–50%; (C) Percentage of positive tumor cells between 51–75%; (D) Percentage of positive tumor cells less than 10%. Immunohistochemistry, anti-AR antibody: (A and D) ×200; (B and C) ×100. AR: Androgen receptor.

Correlations between classical clinicopathological characteristics and androgen receptor

The statistical analysis showed no significant differences between AR immunoexpression (negative versus positive) and clinicopathological characteristics (Table 2).

Table 2 Androgen receptor immunoexpression related to clinicopathological characteristics

Clinicopathological parameters

	AR immunohistochemical expression

	
Negative ( n =46)

	Positive ( n =78)

	NA

	p-value

	
n

	%

	n

	%

	n (%)

	
Age (median)

				
≤61 years old

	27

	41.54%

	38

	58.46%

		0.283

	
>61 years old

	19

	32.20%

	40

	67.80%

		
cT

			
cT1

	1

	9.10%

	10

	90.90%

		0.150

	
cT2

	25

	38.46%

	40

	61.54%

		
cT3

	7

	53.84%

	6

	46.16%

		
cT4

	13

	37.14%

	22

	62.86%

		
cN

				
cN0

	10

	31.25%

	22

	68.75%

		0.240

	
cN1

	24

	42.86%

	32

	57.14%

		
cN2

	5

	22.73%

	17

	77.27%

		
cN3

	7

	50%

	7

	50%

		
cM

				
cM0

	37

	37.76%

	61

	62.24%

		0.768

	
cM1

	9

	34.62%

	17

	65.38%

		
pT

		25 (20.2%)

		
pT1

	12

	30%

	28

	70%

	0.376

	
pT2

	18

	45%

	22

	55%

	
pT3

	4

	57.14%

	3

	42.86%

		
pT4

	4

	33.33%

	8

	66.67%

		
pN

		25 (20.2%)

		
pN0

	21

	40.38%

	31

	59.62%

		0.948

	
pN1

	10

	35.71%

	18

	64.29%

		
pN2

	4

	33.33%

	8

	66.67%

		
pN3

	3

	42.86%

	4

	57.14%

		
Lymphatic invasion

		25 (20.2%)

		
L0

	21

	36.84%

	36

	63.16%

		0.713

	
L1

	17

	40.48%

	25

	59.52%

		
Vascular invasion

		25 (20.2%)

		
V0

	28

	37.33%

	47

	62.67%

		0.704

	
V1

	10

	41.67%

	14

	58.33%

		
Perineural invasion

		25 (20.2%)

		
Pn0

	32

	39.51%

	49

	60.49%

		0.626

	
Pn1

	6

	33.33%

	12

	66.67%

		
Histological grade

			
G1

	2

	66.67%

	1

	33.33%

		0.546

	
G2

	7

	38.89%

	11

	61.11%

		
G3

	37

	35.92%

	66

	64.08%

		
Histological type

				
Invasive ductal carcinoma NOS

	41

	37.61%

	68

	62.39%

		0.884

	
Metaplastic carcinoma

	3

	30%

	7

	70%

		
Other types

	2

	40%

	3

	60%

		
Stage at diagnosis

			
I

	1

	14.29%

	6

	85.71%

		0.510

	
II

	20

	41.67%

	28

	58.33%

		
III

	17

	38.64%

	27

	61.36%

		
IV

	8

	32%

	17

	68%

		
RCB

		25 (20.2%)

		
0

	3

	25%

	9

	75%

		0.323

	
I

	6

	30%

	14

	70%

		
II

	18

	40.91%

	26

	59.09%

		
III

	11

	47.83%

	12

	52.17%

		
TILs

			
Low grade, <10%

	26

	36.11%

	46

	63.89%

		0.791

	
Intermediate grade, 10–50%

	13

	41.94%

	18

	58.06%

		
High grade, >50%

	7

	33.33%

	14

	66.67%

		
Ki67 index

				
≤50%

	5

	33.33%

	10

	66.67%

		0.748

	
>50%

	41

	37.61%

	68

	62.39%

		
AR: Androgen receptor; n: No. of cases; NA: Not available; NOS: Not otherwise specified; RCB: Residual cancer burden; TILs: Tumor-infiltrating lymphocytes

Correlations between classical clinicopathological characteristics and androgen receptor, and survival parameters

Univariate analysis confirmed statistically significant differences for PFS, in relation to the histological type (p=0.011), tumor staging, distant metastasis and first-line treatment (p<0.000), intensity of TILs (p=0.004), and RCB (p=0.019), respectively.

Poor OS was statistically significant correlated with histological type (p=0.045), tumor staging, lymphatic, vascular and perineural invasion, metastatic lesions, first-line treatment (p<0.000), and RCB (p=0.015), respectively.

However, no significant differences in survival parameters in relation to AR status was found (PFS: p=0.637; OS: p=0.746), suggesting no association between AR immunoexpression and the biological course of disease.

Discussions

Triple-negative BC represents an extensively analyzed entity to establish the overall framework of clinicopathological characteristics, with an impact on defining prognostic and predictive factors. The constant concern to decipher the biological particularities of triple-negative BC has included, among the list of major topics of interest, the association of AR as a hormonal influence element in a non-hormonal carcinogenic profile. AR is a type I nuclear receptor, included in the sexual steroid receptor family, with a role in stimulating cell growth and proliferation through involvement in signaling pathways implicated in breast carcinogenesis [21, 22].

Several studies in the mainstream aimed at the investigation of AR involvement in triple-negative BC. Unlike the luminal subtype, where AR has an inhibitory effect on tumor growth, in the triple-negative subtype, it stimulates tumor development [23]. The obtained results present a wide degree of variability, so contradictory data have not made it possible to formulate a general conclusion that settles the value of AR in this diagnostic entity. Therefore, the relationship between triple-negative BC and AR is far from being clarified.

Within this context, our study focuses on the general profile of triple-negative BC, including the analysis of AR variability and its relationships with tumor traits, thus extending the knowledge on its involvement in breast carcinogenesis.

In our study group, 78% of cases presented AR positive status, a result that exceeds the upper limit documented in the literature. Variable percentages for AR positivity are reported in triple-negative BC cases, especially in the LAR subtype. Recent data indicate intervals between 18–41% [24, 25, 26], or 17.1–38% [27, 28, 29, 30, 31, 32], and also a higher percentage of 50% [33] is stated. The variability of positivity critically depends on the threshold set to define a positive or negative AR profile. This threshold, differing according to the working group, has values either less than 1% or less than 10% [27, 28, 29, 30, 31, 32, 33].

The presence of AR expression is correlated with an average age ranging between 45.3–58.4 years old [24, 25, 27 28, 29, 34]. Our study group had the mean age of 58.73±12.2 years (range 33–85 years) in alignment with literature, and no correlation was found with AR status (positive versus negative). Most studies do not confirm a relationship between AR and patients’ age [26, 31, 35, 36]. Moreover, the age parameter in relation to AR urges multiple discussions because such an evaluation can be influenced by demographic factors, according to which normal AR status differs depending on geographic location [33, 37].

Despite the relatively large number of analyzed cases and the increased AR positivity rate, our study revealed no statistically significant differences between AR immunoexpression and all clinicopathological characteristics, and survival parameters. These results suggested no association between AR status and the biological course of triple-negative BC. The statistical analysis applied for the survival times confirmed only the prognostic role of histological type, tumor stage, distant metastases, TILs, first-line treatment and RCB for PFS, and the relationship between histological type, tumor stage, lymphovascular and perineural invasion, metastatic lesions, first-line treatment and RCB, as negative prognostic factors, and OS.

The literature review shows several studies confirming the association between positive AR and a less aggressive biological profile mirrored through low clinical stage, low histological grade, low mitotic rate, lymphovascular invasion [28], lymph node metastases [25 26, 27, 28, 34, 35, 38, 39], increased five-year disease-free survival (DFS) and OS [18, 24, 26, 29, 30, 34, 36, 40, 41, 42, 43, 44]. However, in a single study, positive AR is associated with increased Ki67 levels [45].

Conversely, negative AR is correlated with a more advanced nodal pathological stage and increased risk of recurrence [25, 30, 31, 34, 35, 38, 39, 46, 47].

Discordant results reveal the relationship between positive AR and increased mortality [42], unfavorable prognosis [41]. Thus, positive AR has been considered a predictor for short DFS and OS in the context of negative lymph node status [48], but without predictive value in the presence of metastatic lymph nodes [48].

Nonetheless, other studies indicate the absence of correlation between AR status, clinicopathological characteristics [33], DFS or OS [27, 35, 39, 44, 45] – these data being consistent with our results.

Several arguments can justify the discordant results in the literature, and also the discrepancy of our data with some of the already published studies. We underline the marked diversity in the design of the studies, starting from the number of patients analyzed, the applied therapy [33], the duration of follow-up, the chosen anti-AR antibody type, and the quantification method. Further discussions can be developed if we consider the relationship between survival times, different types of therapy (radiation therapy, chemotherapy, mastectomy, lumpectomy), and AR status, positive or negative [33].

Conclusions

The analysis of AR’s value as a prognostic factor and/or therapeutic target is currently being investigated through multiple studies. Our study did not validate the correlation of AR status and classical clinicopathological characteristics, including survival parameters. Thus, our results sustain that AR does not affect the biological behavior of triple-negative BC. However, our data confirm the high proportion of invasive ductal carcinoma NOS within triple-negative BC cases, and the relationship between several clinicopathological parameters, PFS and OS, highlighting their prognostic significance.

Conflict of interests

Authors declare no conflict of interests.
==== Refs
References

1 Sung H Ferlay J Siegel RL Laversanne M Soerjomataram I Jemal A Bray F Global Cancer Statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries CA Cancer J Clin 2021 71 3 209 249 33538338
2 Beňačka R Szabóová D Guľašová Z Hertelyová Z Radoňák J Classic and new markers in diagnostics and classification of breast cancer Cancers (Basel) 2022 14 21 5444 5444 36358862
3 Ferlay J Ervik M Lam F Laversanne M Colombet M Mery L Piñeros M Znaor A Soerjomataram I Bray F Global Cancer Observatory: cancer today 2024 Lyon, France International Agency for Research on Cancer (IARC) Press
4 Perou CM Sørlie T Eisen MB van de Jeffrey SS Rees CA Pollack JR Ross DT Johnsen H Akslen LA Fluge O Pergamenschikov A Williams C Zhu SX Lønning PE Børresen-Dale AL Brown PO Botstein D Molecular portraits of human breast tumours Nature 2000 406 6797 747 752 10963602
5 Cancer Genome Comprehensive molecular portraits of human breast tumours Nature 2012 490 7418 61 70 23000897
6 Dent R Trudeau M Pritchard KI Hanna WM Kahn HK Sawka CA Lickley LA Rawlinson E Sun P Narod SA Triple-negative breast cancer: clinical features and patterns of recurrence Clin Cancer Res 2007 13 15 Pt 1 4429 4434 17671126
7 Lehmann BD Bauer JA Chen X Sanders ME Chakravarthy AB Shyr Y Pietenpol JA Identification of human triple-negative breast cancer subtypes and preclinical models for selection of targeted therapies J Clin Invest 2011 121 7 2750 2767 21633166
8 Curtis C Shah SP Chin SF Turashvili G Rueda OM Dunning MJ Speed D Lynch AG Samarajiwa S Yuan Y Gräf S Ha G Haffari G Bashashati A Russell R McKinney S; Green A Provenzano E Wishart G Pinder S Watson P Markowetz F Murphy L Ellis I Purushotham A Børresen-Dale AL Brenton JD Tavaré S Caldas C Aparicio S The genomic and transcriptomic architecture of 2,000 breast tumours reveals novel subgroups Nature 2012 486 7403 346 352 22522925
9 Burstein MD Tsimelzon A Poage GM Covington KR Contreras A Fuqua SA Savage MI Osborne CK Hilsenbeck SG Chang JC Mills GB Lau CC Brown PH Comprehensive genomic analysis identifies novel subtypes and targets of triple-negative breast cancer Clin Cancer Res 2015 21 7 1688 1698 25208879
10 Lehmann BD Jovanović B Chen X Estrada MV Johnson KN Shyr Y Moses HL Sanders ME Pietenpol JA Refinement of triple-negative breast cancer molecular subtypes: implications for neoadjuvant chemotherapy selection PLoS One 2016 11 6 e0157368 e0157368 27310713
11 Hon JDC Singh B Sahin A Du G Wang J Wang VY Deng FM Zhang DY Monaco ME Lee P Breast cancer molecular subtypes: from TNBC to QNBC Am J Cancer Res 2016 6 9 1864 1872 27725895
12 Bando Y Kobayashi T Miyakami Y Sumida S Kakimoto T Saijo Y Uehara H Triple-negative breast cancer and basal-like subtype: pathology and targeted therapy J Med Invest 2021 68 3.4 213 219 34759133
13 Masuda H Baggerly KA Wang Y Zhang Y Gonzalez-Angulo AM Meric-Bernstam F Valero V Lehmann BD Pietenpol JA Hortobagyi GN Symmans WF Ueno NT Differential response to neoadjuvant chemotherapy among 7 triple-negative breast cancer molecular subtypes Clin Cancer Res 2013 19 19 5533 5540 23948975
14 Santonja A Sánchez-Muñoz A Lluch A Chica-Parrado MR Albanell J Chacón JI Antolín S Jerez JM de la de Luque Fernández-De Sousa Vicioso L Plata Y Ramírez-Tortosa CL Álvarez M Llácer C Zarcos-Pedrinaci I Carrasco E Caballero R Martín M Alba E Triple negative breast cancer subtypes and pathologic complete response rate to neoadjuvant chemotherapy Oncotarget 2018 9 41 26406 26416 29899867
15 World Health Organization (WHO) Classification of Tumours Editorial Board Breast tumours WHO Classification of Tumours 5th 2019 Lyon, France International Agency for Research on Cancer (IARC) Press
16 Allred DC Harvey JM Berardo M Clark GM Prognostic and predictive factors in breast cancer by immunohistochemical analysis Mod Pathol 1998 11 2 155 168 9504686
17 Hammond MEH Hayes DF Dowsett M Allred DC Hagerty KL Badve S Fitzgibbons PL Francis G Goldstein NS Hayes M Hicks DG Lester S Love R Mangu PB McShane L Miller K Osborne CK Paik S Perlmutter J Rhodes A Sasano H Schwartz JN Sweep FCG Taube S Torlakovic EE Valenstein P Viale G Visscher D Wheeler T Williams RB Wittliff JL Wolff AC; American Society of Clinical Oncology/College of American Pathologists guideline recommendations for immunohistochemical testing of estrogen and progesterone receptors in breast cancer (unabridged version) Arch Pathol Lab Med 2010 134 7 e48 e72 20586616
18 Mrklić I Pogorelić Z Capkun V Tomić S Expression of androgen receptors in triple negative breast carcinomas Acta Histochem 2013 115 4 344 348 23031358
19 Ismael NEHS Khairy RA Talaat SM El-Fattah FAA Immunohistochemical expression of androgen receptors (AR) in various breast cancer subtypes Open Access Maced J Med Sci 2019 7 8 1259 1265 31110566
20 Wu Q Ma G Deng Y Luo W Zhao Y Li W Zhou Q Prognostic value of Ki-67 in patients with resected triple-negative breast cancer: a meta-analysis Front Oncol 2019 9 1068 1068 31681601
21 Narayanan R Dalton JT Androgen receptor: a complex therapeutic target for breast cancer Cancers (Basel) 2016 8 12 108 108 27918430
22 Venema CM Bense RD Steenbruggen TG Nienhuis HH Qiu SQ van Kruchten Brown M Tamimi RM Hospers GAP Schröder CP Fehrmann RSN de Vries Consideration of breast cancer subtype in targeting the androgen receptor Pharmacol Ther 2019 200 135 147 31077689
23 Dieci MV Tsvetkova V Griguolo G Miglietta F Mantiero M Tasca G Cumerlato E Giorgi CA Giarratano T Faggioni G Falci C Vernaci G Menichetti A Mioranza E Di Liso Frezzini S Saibene T Orvieto E Guarneri V Androgen receptor expression and association with distant disease-free survival in triple negative breast cancer: analysis of 263 patients treated with standard therapy for stage I-III disease Front Oncol 2019 9 452 452 31245286
24 Astvatsaturyan K Yue Y Walts AE Bose S Androgen receptor positive triple negative breast cancer: clinicopathologic, prognostic, and predictive features PLoS One 2018 13 6 e0197827 e0197827 29883487
25 Teoh PY Tan GC Mahsin H Wong YP Androgen receptor expression in triple negative breast carcinoma and its association with the clinicopathological parameters Malays J Pathol 2019 41 2 125 132 31427547
26 Riaz N Idress R Habib S Lalani EN Lack of androgen receptor expression selects for basal-like phenotype and is a predictor of poor clinical outcome in non-metastatic triple negative breast cancer Front Oncol 2020 10 1083 1083 32850312
27 McGhan LJ McCullough AE Protheroe CA Dueck AC Lee JJ Nunez-Nateras R Castle EP Gray RJ Wasif N Goetz MP Hawse JR Henry TJ Barrett MT Cunliffe HE Pockaj BA Androgen receptor-positive triple negative breast cancer: a unique breast cancer subtype Ann Surg Oncol 2014 21 2 361 367 24046116
28 Jam S Abdollahi A Khazaeipour Z Omranipour R Najafi M Androgen receptor expression in triple-negative breast cancer Arch Breast Cancer 2019 6 2 92 95
29 Payandeh M Shazad B Madani S Ramezani M Sadeghi M Androgen receptor expression and its correlation with other risk factors in triple negative breast cancers: a report from Western Iran Asian Pac J Cancer Prev 2016 17 7 3321 3324 27509970
30 Lyalkin SA Verevkina NO Alekseyenko OO Syvak LA Prognostic role of androgen receptor expression in patients with metastatic triple negative breast cancer Exp Oncol 2020 42 2 140 143 32602289
31 Zakaria F El-Mashad N Mohamed D Androgen receptor expression as a prognostic and predictive marker in triple-negative breast cancer patients Alexandria J Med 2016 52 2 131 140
32 Adamo B Ricciardi GRR Ieni A Franchina T Fazzari C Sanò MV Angelico G Michele C Tuccari G Adamo V The prognostic significance of combined androgen receptor, E-cadherin, Ki67 and CK5/6 expression in patients with triple negative breast cancer Oncotarget 2017 8 44 76974 76986 29100362
33 Dubrava AL Kyaw PSP Newman J Pringle J Westhuyzen J La Hera Shakespeare TP Sakalkale R Aherne NJ Androgen receptor status in triple negative breast cancer: does it correlate with clinicopathological characteristics Breast Cancer (Dove Med Press) 2023 15 359 371 37197610
34 Cabezas-Quintario MA Zenzola V Arguelles M Pérez-Fernández E Androgen receptor as prognostic marker in triple-negative breast cancer patients J Med Surg Pathol 2018 3 4 1000170 1000170
35 Liu YX Zhang KJ Tang LL Clinical significance of androgen receptor expression in triple negative breast cancer - an immunohistochemistry study Oncol Lett 2018 15 6 10008 10016 29844843
36 Hu XQ Chen WL Ma HG Jiang K Androgen receptor expression identifies patient with favorable outcome in operable triple negative breast cancer Oncotarget 2017 8 34 56364 56374 28915596
37 Bhattarai S Klimov S Mittal K Krishnamurti U Li XB Oprea-Ilies G Wetherilt CS Riaz A Aleskandarany MA Green AR Ellis IO Cantuaria G Gupta M Manne U Agboola J Baskovich B Janssen EAM Callagy G Walsh EM Mehta A Dogra A Shet T Gajaria P Traina T Nggada HA Omonisi A Ahmed SA Rakha EA Rida P Aneja R Prognostic role of androgen receptor in triple negative breast cancer: a multi-institutional study Cancers (Basel) 2019 11 7 995 995 31319547
38 Rampurwala M Wisinski KB O’Regan R Role of the androgen receptor in triple-negative breast cancer Clin Adv Hematol Oncol 2016 14 3 186 193 27058032
39 Sunar V T Dogan Sarici F Ates O Akin S Baspinar B Aksoy S Altundag K Association between androgen receptor status and prognosis in triple negative breast cancer J BUON 2018 23 5 1325 1330 30570854
40 Ogawa Y Hai E Matsumoto K Ikeda K Tokunaga S Nagahara H Sakurai K Inoue T Nishiguchi Y Androgen receptor expression in breast cancer: relationship with clinicopathological factors and biomarkers Int J Clin Oncol 2008 13 5 431 435 18946753
41 Park S Koo J Park HS Kim JH Choi SY Lee JH Park BW Lee KS Expression of androgen receptors in primary breast cancer Ann Oncol 2010 21 3 488 492 19887463
42 Hu R Dawood S Holmes MD Collins LC Schnitt SJ Cole K Marotti JD Hankinson SE Colditz GA Tamimi RM Androgen receptor expression and breast cancer survival in postmenopausal women Clin Cancer Res 2011 17 7 1867 1874 21325075
43 Luo X Shi YX Li ZM Jiang WQ Expression and clinical significance of androgen receptor in triple negative breast cancer Chin J Cancer 2010 29 6 585 590 20507730
44 Qu Q Mao Y Fei XC Shen KW The impact of androgen receptor expression on breast cancer survival: a retrospective study and meta-analysis PLoS One 2013 8 12 e82650 e82650 24324816
45 Pistelli M Caramanti M Biscotti T Santinelli A Pagliacci A De Lisa Ballatore Z Ridolfi F Maccaroni E Bracci R Berardi R Battelli N Cascinu S Androgen receptor expression in early triple-negative breast cancer: clinical significance and prognostic associations Cancers (Basel) 2014 6 3 1351 1362 24978437
46 Rakha EA El-Sayed ME Green AR Lee AHS Robertson JF Ellis IO Prognostic markers in triple-negative breast cancer Cancer 2007 109 1 25 32 17146782
47 Sutton LM Cao D Sarode V Molberg KH Torgbe K Haley B Peng Y Decreased androgen receptor expression is associated with distant metastases in patients with androgen receptor-expressing triple-negative breast carcinoma Am J Clin Pathol 2012 138 4 511 516 23010705
48 Choi JE Kang SH Lee SJ Bae YK Androgen receptor expression predicts decreased survival in early stage triple-negative breast cancer Ann Surg Oncol 2015 22 1 82 89 25145503
