Phenotypic evaluation of the basal-like subtype of invasive breast carcinoma.

Microarray profiling of invasive breast carcinomas has identified five distinct subtypes of tumors (luminal A, luminal B, normal breast-like, HER2 overexpressing, and basal-like) that are associated with different clinical outcomes. The basal-like subtype is associated with poor clinical outcomes and is the subtype observed in BRCA1-related breast cancers. The aim of this study was to characterize the histologic and immunophenotypic properties of breast basal-like carcinomas that were first positively identified using DNA microarray analysis. Detailed histologic review was performed on 56 tumors with known microarray profiles (23 basal-like, 23 luminal, and 12 HER2+). Immunohistochemistry for estrogen receptor (ER), HER2, EGFR, smooth muscle actin (SMA), p63, CD10, cytokeratin 5/6, cytokeratin 8/18, and vimentin was performed on 18 basal-like, 16 luminal, and 12 HER2+ tumors. The basal-like tumors were grade 3 ductal/NOS (21/23) or metaplastic (2/23) carcinomas that frequently showed geographic necrosis (17/23), a pushing border of invasion (14/23), and a stromal lymphocytic response (13/23). Most basal-like tumors showed immunoreactivity for vimentin (17/18), luminal cytokeratin 8/18 (15/18), EGFR (13/18), and cytokeratin 5/6 (11/18), while positivity for the myoepithelial markers SMA (4/18), p63 (4/18) and CD10 (2/18) was infrequent. All basal-like tumors tested were ER- and HER2-. Morphologic features significantly associated with the basal-like subtype included markedly elevated mitotic count (P<0.0001), geographic tumor necrosis (P=0.0003), pushing margin of invasion (P=0.0001), and stromal lymphocytic response (P=0.01). The most consistent immunophenotype seen in the basal-like tumors was negativity for ER and HER2, and positivity for vimentin, EGFR, cytokeratin 8/18, and cytokeratin 5/6. The infrequent expression of myoepithelial markers in basal-like carcinomas does not support a direct myoepithelial cell derivation of these tumors. These findings should further assist in the identification of basal-like carcinomas in clinical specimens, facilitating treatment and epidemiologic studies of this tumor subtype.     

Identification of different subtypes of breast cancer using tissue microarray

Breast cancer may be classified into luminal A, luminal B, HER2+/ER-, basal-like and normal-like subtypes based on gene expression profiling or immunohistochemical (IHC) characteristics. The main aim of the present study was to classify breast cancer into molecular subtypes based on immunohistochemistry findings and correlate the subtypes with clinicopathological factors. Two hundred and seventeen primary breast carcinomas tumor tissues were immunostained for ER, PR, HER2, CK5/6, EGFR, CK8/18, p53 and Ki67 using tissue microarray technique. All subtypes were significantly associated with Malay ethnic background (p=0.035) compared to other racial origins. The most common subtypes of breast cancers were luminal A and was significantly associated with low histological grade (p<0.000) and p53 negativity (p=0.003) compared to HER2+/ER-, basal-like and normal-like subtypes with high histological grade (p<0.000) and p53 positivity (p=0.003). Luminal B subtype had the smallest mean tumor size (p=0.009) and also the highest mean number of lymph nodes positive (p=0.032) compared to other subtypes. All markers except EGFR and Ki67 were significantly associated with the subtypes. The most common histological type was infiltrating ductal carcinoma, NOS. Majority of basal-like subtype showed comedo-type necrosis (68.8%) and infiltrative margin (81.3%). Our studies suggest that IHC can be used to identify the different subtypes of breast cancer and all subtypes were significantly associated with race, mean tumor size, mean number of lymph node positive, histological grade and all immunohistochemical markers except EGFR and Ki67.     

Molecular classifications of breast carcinoma with similar terminology and different definitions: are they the same?

There are 4 major molecular classifications in the literature that divide breast carcinoma into basal and nonbasal subtypes, with basal subtypes associated with poor prognosis. Basal subtype is defined as positive for cytokeratin (CK) 5/6, CK14, and/or CK17 in CK classification; negative for ER, PR, and HER2 in triple negative (TN) classification; negative for ER and negative or positive for HER2 in ER/HER2 classification; and positive for CK5/6, CK14, CK17, and/or EGFR; and negative for ER, PR, and HER2 in CK/TN classification. These classifications use similar terminology but different definitions; it is critical to understand the precise relationship between them. We compared these 4 classifications in 195 breast carcinomas and found that (1) the rates of basal subtypes varied from 5% to 36% for ductal carcinoma in situ and 14% to 40% for invasive ductal carcinoma. (2) The rates of basal subtypes varied from 19% to 76% for HG carcinoma and 1% to 7% for NHG carcinoma. (3) The rates of basal subtypes were strongly associated with tumor grades (P < .001) in all classifications and associated with tumor types (in situ versus invasive ductal carcinomas) in TN (P < .001) and CK/TN classifications (P = .035). (4) These classifications were related but not interchangeable (kappa ranges from 0.140 to 0.658 for HG carcinoma and from 0.098 to 0.654 for NHG carcinoma). In conclusion, although these classifications all divide breast carcinoma into basal and nonbasal subtypes, they are not interchangeable. More studies are needed to evaluate to their values in predicting prognosis and guiding individualized therapy.     

Ductal carcinoma in situ with basal-like phenotype: a possible precursor to invasive basal-like breast cancer.

Basal-like carcinomas have recently been identified in gene expression profiling studies as a subtype of invasive breast cancer. These lesions are estrogen receptor (ER)-negative, progesterone receptor (PR)-negative, and HER2-negative (triple negative), and typically express basal cytokeratins, epidermal growth factor receptor (EGFR), and/or c-kit. As poorly differentiated invasive ductal carcinomas, they presumably have a ductal carcinoma in situ (DCIS) precursor with similar cytologic and immunophenotypic features. However, the frequency and even the existence of a DCIS lesion with an immunophenotype analogous to that of invasive basal-like carcinomas have not been previously evaluated. We studied 66 cases of high nuclear grade DCIS using antibodies to ER, PR, HER2, three basal cytokeratins, EGFR, and c-kit to determine the frequency of the triple negative phenotype, and to determine the relationship between the triple negative phenotype and expression of basal cytokeratins and other biomarkers characteristically expressed by invasive basal-like carcinomas. Four cases (6%) exhibited the triple negative phenotype; the remaining cases showed other combinations of ER, PR, and HER2 expression (nontriple negative). Basal cytokeratins, EGFR, or both were expressed by all four triple negative lesions, but by only 21 of 51 (42%) nontriple negative cases (P = 0.04). We conclude that a small proportion of high-grade ductal carcinomas in situ exhibit an ER-negative/PR-negative/HER2-negative (triple negative) phenotype, and these lesions more commonly show expression of basal cytokeratins and/or EGFR than nontriple negative high-grade DCIS. Given that invasive breast cancers typically share immunophenotypic features with the ductal carcinoma in situ from which they arise, our findings raise the possibility that the triple-negative, basal cytokeratin and/or EGFR-positive DCIS lesions we identified represent a precursor lesion to invasive basal-like carcinomas.     

免疫组织化学诊断标准对基底细胞样型乳腺癌预后分析的影响

目的 探讨不同的免疫组织化学(IHC)诊断标准对基底细胞样型乳腺癌(BLBC)预后分析的影响及意义.方法 收集1996-2002年并有5年以上随访资料的浸润性乳腺癌284例,IHC检测ER、PR、HER2、CK5/6、CK14、表皮生长因子受体(EGFR)的表达,按照Nielsen标准[ER-/HER2-,CK5/6+和(或)EGFR+]、Kim标准[ER-/PR-/HER2-,CK5/6+和(或)CK14+和(或)EGFR+]、基底样CK标准[CK5/6+和(或)CK14+]、三阴性标准[ER-/PR-/HER2-]标准分型并比较其5年生存率.结果 在4种标准下,284例浸润性乳腺癌中BLBC的发病率分别为15.5%(44例)、14.8%(42例)、43.3%(123例)、21.1%(60例);复发率分别为18.2%(8/44)、21.4%(9/42)、10.6%(13/123)、11.7%(7/60),均明显高于其他亚型,但仅在Nielsen和Kim标准中之BLBC型的复发率与其他型差异有统计学意义.Nielsen和三阴性标准中BLBC型之5年无病生存率(均P<0.01)和5年总生存率(P<0.05和0.01)显著低于腺腔A型;Kim标准中BLBC型5年无病生存率显著低于腺腔A型(P<0.01),但5年总生存率与其他分型差异无统计学意义;基底样CK标准的BLBC型与非BLBC型之5年生存率差异无统计学意义.结论 在不同的IHC诊断标准下BLBC均呈高复发和预后差的趋势,但不同的分型标准影响其预后分析结果 ,相对完善、统一的诊断标准是亟待解决的问题.     

基底细胞样型浸润性乳腺癌病理形态观察

目的 观察基底细胞样型浸润性乳腺癌的形态特点,为该类型癌的诊断提供依据.方法 收集109例乳腺浸润性导管癌存档蜡块,用单克隆抗体CK56、CK14、CK818、CK34βE12、calponin、p63、CD10、ER、PR和c-erbB-2进行免疫组织化学Max VisionTM法染色,按照免疫表型将本组分为5种类型:腺腔A型(ER+HER2-),腺腔B型(ER+HER2+),正常乳腺样型(ER-HER2-),HER2过表达型和基底细胞样型(至少表达一种基底细胞角蛋白和(或)肌上皮标记物,且ER-HER2-).重点观察基底细胞样型的组织形态表现.结果 腺腔A型48例(44.0%),腺腔B型15例(13.8%),HER2过表达型15例(13.8%),正常乳腺型10例(9.2%),基底细胞样型19例(17.4%).2例除肌上皮标记物外,还同时表达c-erbB-2和(或)ER,组织类型暂未定.在19例基底细胞样型中有16例表达CK56,17例表达CK818,11例表达CK14,18例表达CK34βE12,5例表达p63,6例表达CD10,1例表达calponin.肿瘤直径1.2～7.0 cm(平均3.9 cm);其中＞5 cm者6例.除1例病变以高级别导管内癌为主外,组织学分级为2级者9例,3级者9例,与非基底细胞样型相比3级者显著增多(P＜0.01).基底细胞样型主要组织形态表现包括:13例癌组织呈单纯推挤性(膨胀性)生长,各例边缘均可见到淋巴细胞,18例肿瘤以巢状和(或)片状排列为主,17例核分级为3级,并可见到散在巨核和(或)怪核细胞,7例呈合体细胞样生长,17例有粉刺样坏死,上述形态出现率与非基底细胞样癌比较均显著增多(P＜0.01).结论 基底细胞样型浸润性乳腺癌最有诊断性价值的形态特点是推挤性浸润边缘、周边有显著的淋巴组织、粉刺样坏死、散在巨怪细胞、大巢或片状组织结构和呈合体细胞样生长.     

乳腺浸润性导管癌分子亚型与临床病理特征及预后的关系

目的 检测乳腺浸润性导管癌的临床病理特征及特定蛋白的表达情况,对其进行分型,探讨各哑型与预后的关系.方法 采用免疫组织化学EnVision法检测128例浸润性导管癌ER、PR、HER2和CK5/6的表达,参考文献报道的免疫分型方法 对其分型,并对HER2过表达型9例进行FISH检测.结果 ER、PR、HER2和CKS/6在本组128例浸润性导管癌中的阳性表达率分别为67%(86/128)、45%(58/128)、27%(34/128)和27%(34/128),并将128例分为5种免疫哑型,管腔A型55%(70/128),管腔B型20%(25/128),HER2过表达型7%(9/128),基底细胞样型10%(13/128),无法分类型8%(11/128).FISH检测HER2过表达型9例均为HER2基因扩增.各分子亚型间预后差异具有统计学意义,管腔A型预后最好,基底细胞型预后较差.多因素分析,乳腺癌临床分期和免疫分型是独立的预后因素.月经状态在乳腺癌各免疫亚型中的分布差异有统计学意义.结论 通过检测ER、PR、HER2和CK5/6的表达可以将乳腺浸润性导管癌分成具有不同生物学行为的5个免疫亚型,对于评估预后,指导治疗具有一定的意义.     

乳腺浸润性导管癌分子亚型与临床病理特征及预后的关系

目的 检测乳腺浸润性导管癌的临床病理特征及特定蛋白的表达情况,对其进行分型,探讨各哑型与预后的关系.方法 采用免疫组织化学EnVision法检测128例浸润性导管癌ER、PR、HER2和CK5/6的表达,参考文献报道的免疫分型方法 对其分型,并对HER2过表达型9例进行FISH检测.结果 ER、PR、HER2和CKS/6在本组128例浸润性导管癌中的阳性表达率分别为67%(86/128)、45%(58/128)、27%(34/128)和27%(34/128),并将128例分为5种免疫哑型,管腔A型55%(70/128),管腔B型20%(25/128),HER2过表达型7%(9/128),基底细胞样型10%(13/128),无法分类型8%(11/128).FISH检测HER2过表达型9例均为HER2基因扩增.各分子亚型间预后差异具有统计学意义,管腔A型预后最好,基底细胞型预后较差.多因素分析,乳腺癌临床分期和免疫分型是独立的预后因素.月经状态在乳腺癌各免疫亚型中的分布差异有统计学意义.结论 通过检测ER、PR、HER2和CK5/6的表达可以将乳腺浸润性导管癌分成具有不同生物学行为的5个免疫亚型,对于评估预后,指导治疗具有一定的意义.     

乳腺浸润性导管癌分子亚型与临床病理特征及预后的关系

目的 检测乳腺浸润性导管癌的临床病理特征及特定蛋白的表达情况,对其进行分型,探讨各哑型与预后的关系.方法 采用免疫组织化学EnVision法检测128例浸润性导管癌ER、PR、HER2和CK5/6的表达,参考文献报道的免疫分型方法 对其分型,并对HER2过表达型9例进行FISH检测.结果 ER、PR、HER2和CKS/6在本组128例浸润性导管癌中的阳性表达率分别为67%(86/128)、45%(58/128)、27%(34/128)和27%(34/128),并将128例分为5种免疫哑型,管腔A型55%(70/128),管腔B型20%(25/128),HER2过表达型7%(9/128),基底细胞样型10%(13/128),无法分类型8%(11/128).FISH检测HER2过表达型9例均为HER2基因扩增.各分子亚型间预后差异具有统计学意义,管腔A型预后最好,基底细胞型预后较差.多因素分析,乳腺癌临床分期和免疫分型是独立的预后因素.月经状态在乳腺癌各免疫亚型中的分布差异有统计学意义.结论 通过检测ER、PR、HER2和CK5/6的表达可以将乳腺浸润性导管癌分成具有不同生物学行为的5个免疫亚型,对于评估预后,指导治疗具有一定的意义.     

Metaplastic breast carcinomas are basal-like tumours

AIMS: Recently, an immunohistochemical panel comprising antibodies against HER2, oestrogen receptor (ER), epidermal growth factor receptor (EGFR) and cytokeratin (CK) 5/6 was reported to identify basal-like breast carcinomas, as defined by cDNA microarrays. Our aim was to analyse a series of metaplastic breast carcinomas (MBCs) using this panel plus two other basal markers (CK14 and p63) and progesterone receptor (PR), to define how frequently MBCs show a basal-like immunophenotype. METHODS AND RESULTS: Sixty-five cases were retrieved from the pathology archives of the authors' institutions and reviewed by three of the authors. Immunohistochemistry with antibodies for HER2, ER, EGFR, CK5/6, CK14 and p63 was performed according to standard methods. All but six cases (91%) showed the typical immunoprofile of basal-like tumours (ER- and HER2-, EGFR+ and/or CK5/6+). When CK14 and p63 were added to the panel, two additional cases could be classified as basal-like. The majority of MBCs lacked PR, except 4/19 (21%) carcinomas with squamous metaplasia. CONCLUSIONS: Our results demonstrate that MBCs show a basal-like phenotype, regardless of the type of metaplastic elements. Moreover, as these neoplasms frequently overexpress EGFR (57%), patients with MBC may benefit from treatment with anti-EGFR drugs.     

乳腺癌分子标志和分子分型

乳腺癌是生物学高度异质性的肿瘤,雌激素受体(estrogen recept,ER)、孕激素受体(progester-one recept,PR)、人表皮生长因子受体2(human epidermal growth factor 2,HER-2)是目前预测预后和指导治疗重要的分子标志。随着分子生物学技术的不断进步,可以根据ER、PR、HER-2表达状态和细胞形态学可以将乳腺癌大致分成4至5个亚群,即Luminal(ER /PR )、HER-2 (ER-,PR-,HER-2 )、Basal-like(ER-,PR-,HER-2-)和Normal-like等,它们在临床治疗反应和生存方面截然不同。因此,对乳腺癌进行分子标志检测或分子分型有利于判断患者的临床预后和指导临床治疗。     

Identification of molecular phenotypes in canine mammary carcinomas with clinical implications: application of the human classification

Similarly to humans, canine mammary cancer represents a heterogeneous group in terms of morphology and biological behaviour. In the present study, we evaluated a series of canine mammary carcinomas based on a new human classification, initially based on gene expression profiling analysis. Similarly to human breast cancer, by using an immunohistochemistry surrogate panel based on five molecular markers [estrogen receptor, human epidermal growth factor receptor 2 (HER2), cytokeratin 5, p63 and P-cadherin], we were able to classify canine mammary carcinomas into four different subtypes: luminal A [estrogen receptor (ER)+/HER2-; 44.8%], luminal B (ER+/HER2+; 13.5%), basal (ER-/HER2- and a basal marker positive; 29.2%) and HER2 overexpressing tumours (ER-/HER2+; 8.3%). Luminal A-type tumours were characterised by lower grade and proliferation rate, whereas basal-type tumours were mostly high grade, high proliferative and positive for cytokeratin 5, p63 and P-cadherin. In addition, as in humans, basal subtype was significantly associated with shorter disease-free and overall survival rates, and we propose canine mammary carcinomas as a suitable natural model for the study of this particular subset of human carcinomas.     

P-cadherin and cytokeratin 5: useful adjunct markers to distinguish basal-like ductal carcinomas in situ

Gene expression profiles of invasive breast carcinomas have identified a subgroup of tumours with worse prognosis, which have been called "basal-like". These are characterized by a specific pattern of expression, being estrogen receptor (ER) and HER2 negative, and frequently expressing at least one basal marker such as basal cytokeratins or epidermal growth factor receptor (EGFR). Previously, our group characterized basal-like tumours in a series of invasive breast carcinomas using P-cadherin (P-CD), p63 and cytokeratin 5 (CK5). Based on that study, we hypothesized that those high-grade basal-like invasive carcinomas might have a pre-invasive counterpart, which could be identified using the same approach. A series of 79 ductal carcinomas in situ (DCIS) were classified into distinct subgroups according to their ER, HER2 and basal markers expression. Luminal DCIS expressed ER and constituted 64.6% of the series; the HER2 overexpressing tumours did not express ER and represented 25.3% of the cases, whereas 10.1% lack the expression of ER and HER2 and expressed at least one basal marker (P-CD, CK5, CK14, p63, vimentin and/or EGFR). These basal-like DCIS were mostly high-grade, with comedo-type necrosis, and consistently showed expression of P-CD and CK5. In conclusion, DCIS with a basal-like phenotype represent a small percentage in our series, being P-CD and CK5, the most useful adjunct markers to distinguish this subset of carcinomas in situ of the breast.     

PLK1在乳腺癌分子亚型中的表达及其与基底细胞样型乳腺癌的关系

目的:探讨乳腺癌各分子亚型中PLK1的表达及其与基底细胞样型乳腺癌的关系.方法:回顾性分析803例乳腺浸润性导管癌的临床病理资料,按照Nielsen标准将乳腺浸润性导管癌分成腺腔A型、腺腔B型、HER-2过表达型、基底细胞样型和普通乳腺样型.检测PLK1在5种不同乳腺癌亚型中的表达水平并分析其与基底细胞样型乳腺癌的关系.结果:PLK1在基底细胞样型、普通乳腺样型、HER-2过表达型、腺腔A型及腺腔B型乳腺癌中的阳性表达率分别为58.94%(56/95),39.39%(65/165),33.33%(22/66),17.91%(79/441)及5.56%(2/36).PLK1在ER阴性的乳腺癌分子亚型中的表达显著高于其在ER阳性的乳腺癌分子亚型中的表达,差异具有统计学意义(P<0.05);PLK1的表达与ER呈负相关,与Ki-67表达呈正相关(P<0.01),与HER-2无显著相关性.ER阴性乳腺癌中,PLK1在基底细胞样型乳腺癌中的阳性表达率最高,显著高于其在HER-2过表达型及普通乳腺样型乳腺癌中的表达,差异有统计学意义(P<0.05).而HER-2过表达型与普通乳腺样型中相比,PLK1的表达差异无统计学意义(P=0.390).PLK1的表达与基底细胞样型乳腺癌的淋巴结转移及临床分期相关,而与肿瘤大小及患者年龄无关.结论:PLK1过表达可能与ER阴性的基底细胞样型乳腺癌关系更密切,并在基底细胞样型乳腺的浸润、转移中起重要作用.     

Metaplastic and medullary mammary carcinomas do not express mammaglobin

Mammaglobin A (MG-A) is purportedly useful for detecting metastatic carcinomas suspected to be of breast origin and has been advocated as a useful marker of micrometastasis in sentinel lymph nodes and minimal residual tumor in bone marrow. Little is known about its expression frequency in histologic subtypes of breast cancer. Excisional biopsy specimens from 1,079 untreated invasive mammary carcinomas were evaluated for immunohistochemical expression of MG-A. In addition to estrogen (ER) and progesterone receptors (PR) and HER2, staining for p63 and HLA-DR was used to further characterize histologic subtypes. Of the carcinomas, 36 were classified as metaplastic (based on morphologic features, ER-/PR-/HER2-, p63+), 38 as medullary (ER-/PR-/HER2-, HLA-DR+), and 1,005 as ductal, no special type (NST). All metaplastic and medullary carcinomas were negative for MG-A. Of 1,005 ductal carcinomas, NST, 492 (49.0%) were MG-A+, 62.0% with a reaction in fewer than 25% of the cells. MG-A immunohistochemical studies failed to detect all medullary and metaplastic cancers and more than 50% of ductal carcinomas, NST. In two thirds of MG-A+ ductal carcinomas, the reaction was only focal and usually in a minority of cells. These findings suggest that MG-A has limited value in identifying the mammary origin of carcinomas, particularly in small biopsy specimens used to detect metastasis or minimal residual disease.     

Molecular morphological approach to the pathological study of development and advancement of human breast cancer

Since the concept of gene profile-based intrinsic subtypes was proposed, various studies on pathological characteristics have been performed. Particularly, triplenegative (TN) breast cancer, which is negative for all hormone receptors [estrogen receptor (ER) and/or progesterone receptor (PgR) and human epidermal growth factor 2 (HER2)], has been attracting attention because effects of endocrine and targeting therapies cannot be anticipated and thus selecting a treatment method is difficult. TN cancer accounts for about 10%–15% of all invasive breast cancer cases in Japanese, which is significantly lower than the incidence reported in the United States. Cytokeratin (CK) 5/6 or epidermal growth factor receptor (EGFR) is positive in 80%, being classified as basal-like carcinoma, but it should be understood that TN breast cancer and basal-like carcinoma are not necessarily the same. Criteria for positivity judgment of ER, PgR, and HER2 were established to select treatment in cases positive for each marker, and greater importance is attached to strict accuracy control. Inversely, the level of negative findings to judge TN varies among the judgment criteria. In any case, the prognosis of TN breast cancer is poor. Pathologically, TN breast cancer shows certain morphological characteristics, such as high grade and a pushing margin, and abnormalities of BRCA1 and p53 are frequently noted. At present, as no effective therapeutic strategy has been established for TN breast cancer, further clarification of the molecular biological characteristics of such cancers is needed. In addition, the incidence of TN-type ductal carcinoma in situ (DCIS) is low, suggesting that TN does not remain preinvasive DCIS for a prolonged period and that it transforms to invasive cancer in an early stage. Because mammary gland basal cells have characters of progenitor or stem cells that differentiate into both luminal epithelium and myoepithelial cells, these cells may be utilized for the differential diagnosis of the benignity or malignancy of intraductal lesions in routine pathological practice. As proliferation markers, such as Ki-67, and multiple gene arrays for gene signature are also utilized to select adjuvant therapy, analysis may progress further in the future.     

Molecular classification predicts survival for breast cancer patients in Vietnam: a single institutional retrospective analysis

Background: The Bhagarva surrogate molecular subtype definitions classify invasive breast cancer into seven the different subgroups based on immunohistochemical (IHC) criteria according to expression levels of markers as ER, PR, HER2, EGFR and/or basal cytokeratin (CK5/6) which are different in prognosis and responsiveness to adjuvant therapy. Purpose: The present study aimed to classify primary breast cancers and directly compares the prognostic significance of the intrinsic subtypes. Methods: The current study was conducted on 522 breast cancer patients who had surgery, but had not received neoadjuvant chemotherapy, from 2011 to 2014. The clinicopathologic characteristics were recorded. IHC staining was performed for ER, PR, HER2, Ki67, CK5/6, EGFR and D2-40 markers. All breast cancer patients were stratified according to Bhagarva criteria. The followed-up patients’ survival was analyzed by using Kaplan-Meier and Log-Rank models. Results: The luminal A (LUMA) was observed at the highest rate (32.5%). Non-basal-like triple negative phenotype (TNB-) and Luminal A HER2-Hybrid (LAHH) were the least common (3.3% in both). LUMA and luminal B (LUMB) were significantly associated with better prognostic features compared to HER2, basal-like triple negative phenotype (TNB+) and TNB-. Statistically significant differences were demonstrated between overall survival (OS), disease-free survival (DFS) and molecular subtypes (P<0.05), of which LUMB and LUMA had the highest rate of OS and DFS being 97.2 and 93.7%; and 97.2 and 90.5%, respectively. Conversely, HER2 revealed the worst prognosis with the lowest prevalence of OS and DFS (72.5 and 69.9%, respectively). Conclusion: The molecular subtypes had a distinct OS and DFS. The intrinsic stratification displayed inversely to clinicopathological features in breast cancer.     

Basal-HER2 phenotype shows poorer survival than basal-like phenotype in hormone receptor-negative invasive breast cancers

Previous studies have shown conflicting results on prognostic significance of basal-like breast tumors, but hormone receptor is a confusing factor in most of the prognostic evaluations. We aimed to characterize the prognostic features of basal-like tumors without the influence of hormone receptor status in a series of hormone receptor-negative breast tumors. Using tissue microarray and immunohistochemistry methods, according to the expression of HER2 and basal markers (CK5/6, CK14, EGFR), we categorized 713 consecutive hormone receptor-negative invasive breast cancers into 3 subtypes: HER2 (HER2+), basal-like (HER2-, any basal marker+), and null (HER2-, all basal markers-). The HER2 phenotype was subdivided into pure-HER2 (HER2+, all basal markers-) and basal-HER2 (HER2+, any basal marker+) subgroups. Expression of p53, p63, vimentin, and BRCA1 was assessed immunochemically. Basal-like tumors showed significantly higher grade, more frequent recurrence, and higher expression of vimentin and p63 than HER2 and null phenotypes. Basal-HER2 phenotype had significantly younger mean age and expressed a higher level of p53 and vimentin like basal-like and/or HER2 phenotypes. However, unlike all the other hormone receptor-negative phenotypes, they highly expressed BRCA1. No significant difference was found in 5-year survival among basal-like and the other hormone receptor-negative phenotypes, except for basal-HER2, which showed poorer 5-year overall survival than basal-like tumors. In conclusion, although basal-like breast tumors have distinct clinicopathologic and immunohistochemical features, they have similar 5-year survival compared with the other hormone receptor-negative tumors including HER2 and null phenotypes. However, there exists a small group of hormone receptor-negative tumors expressing HER2 and basal markers simultaneously. This small group of tumors showed significantly poorer 5-year overall survival than basal-like breast tumors and might require different treatment strategy.     

Lack of expression of androgen receptor may play a critical role in transformation from in situ to invasive basal subtype of high-grade ductal carcinoma of the breast

Androgen receptor has been implicated in the pathogenesis of breast carcinoma. In this study, we explored the potential role of androgen receptor in breast cancer by analyzing its expression using immunohistochemistry and its relationship with tumor progress (ductal carcinoma in situ [DCIS] versus invasive ductal carcinoma [IDC]); nuclear grades (high grade [HG] versus non-high grade); expression of estrogen receptor (ER), progesterone receptor (PR), HER-2; and 3 molecular classifications: cytokeratin classification, triple (ER/PR/HER-2) negative classification, and ER/HER-2 classification in 184 breast carcinomas. We found that (1) lack of androgen receptor expression was associated with HG-IDC and with basal subtypes of HG-IDC, suggesting androgen receptor may play an important role in preventing the invasive transformation in this subgroup of breast carcinoma. (2) HG-IDC and HG-DCIS more frequently expressed androgen receptor than ER (55%-93% for androgen receptor and 18%-30% for ER) and were frequently androgen receptor+/ER- (63% for HG-DCIS and 39% for HG-IDC), which made androgen receptor a possible therapeutic target. (3) One third of HG-IDC was negative for androgen receptor, ER, PR, and HER-2, suggesting that further studies are needed to identify other key molecules for targeted therapy. We purpose that androgen receptor should be routinely measured for breast cancer.