PTEN和p27在乳腺癌分子亚型中的表达及其相关性

目的探讨PTEN、p27在乳腺癌分子亚型中的表达情况,并分析在基底样乳腺癌中的相关性。方法根据Nielsen标准进行分子分型的1 311例乳腺癌组织芯片,用免疫组织化学MaxVision快捷法分别检测PTEN、p27蛋白的表达水平,用原位杂交检测PTEN的mRNA的表达水平。结果在基底样型、HER2过表达、裸表达型、腺腔A型、腺腔B型中,PTEN蛋白表达率为38.9%、44.3%、30.5%、60.2%、68.6%;p27蛋白表达率为35.2%、46.3%、41.4%、55.9%和63.0%;PTEN mRNA表达率为55.9%、67.0%、55.7%、85.0%、80.0%。PTEN和p27蛋白在基底样型、HER2过表达型和裸表达型显著低于腺腔A及腺腔B型表达率(P0.05)。PTEN、p27蛋白的表达均与ER表达正相关(P0.01)。PTEN、p27蛋白的表达在基底样型乳腺癌中正相关(P0.001)。PTENmRNA阳性率ER阴性乳腺癌显著低于ER阳性乳腺癌(P0.001),PTENmRNA与蛋白表达水平显著相关(P0.001)。结论PTEN、p27的失表达可能与ER阴性乳腺癌的发生和发展有关。二者基因在基底样型乳腺癌中相关性的研究为其发病机制的阐明提供帮助。     

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.     

乳腺癌分子亚型中CAIX的表达及临床意义

目的：探讨乳腺癌各分子亚型中碳酸酐酶IX(carbonic anhydrase IX,CAIX)的表达及临床意义。方法：采用免疫组织化学检测CAIX在4种不同乳腺癌分子亚型中的表达水平并分析其与临床病理参数的关系。结果：CAIX在管腔A型、管腔B型、HER-2过表达型和基底样型乳腺癌中的阳性表达率分别为6.65%(28/421)、12.50%(7/56)、60.61%(40/66)和32.31%(84/260)。ER阴性的HER-2过表达型及基底样型乳腺癌组织中,CAIX的阳性表达明显高于ER阳性的管腔A型和管腔B型(P<0.001),并且HER-2过表达型乳腺癌组织CAIX的阳性表达率明显高于基底样型相比,差异有统计学意义。CAIX与乳腺癌的组织学分级、淋巴结转移、临床分期及高增殖指数相关(P<0.05),而与患者年龄、是否绝经及肿瘤大小无关。结论：CAIX在不同乳腺癌分子亚型中的表达具有明显差异,可能与ER阴性乳腺癌关系更密切,并在乳腺癌的侵袭、转移中发挥重要作用,可能成为乳腺癌浸润、进展及预后评估的指标。     

浸润性乳腺癌术前FNA近似分子分型的临床意义

目的探讨浸润性乳腺癌术前细针吸取细胞学(fine needle aspiration,FNA)近似分子分型的可行性及临床意义。方法对42例女性原发性乳腺癌患者术前行细针穿刺术,涂片后进行细胞学诊断。利用免疫细胞化学技术检测ER、PR、HER2、CK5/6和EGFR表达情况,将乳腺癌近似分为腺腔A型(Luminal A)、腺腔B型(Luminal B)、纯HER2过表达型(pure HER2-overexpressing)、基底样型(basal-like)、HER2过表达基底样型(basal-HER2)及正常乳腺型(null)6个分子亚型。将其与术后对应标本的病理学及免疫组化结果进行比较。结果术前穿刺涂片诊断为"高度可疑乳腺癌"及"乳腺癌"的42例女性患者,经术后病理组织学证实均为浸润性乳腺癌,细胞学诊断准确率为100%。在42例乳腺癌细针吸取细胞涂片上利用免疫细胞化学进行术前各分子标记的检测,其中ER/PR阳性率为52.38%(22/42),HER2阳性率为42.86%(18/42),EGFR/CK5/6阳性率为19.04%(8/42)。相对应的石蜡切片经免疫组化检测,ER/PR阳性率分别为52.38%(22/42),HER2阳性率为40.48%(17/42),EGFR/CK5/6阳性率为23.81%(10/42)。其中,1例细胞涂片HER-2为阳性,而对应的石蜡切片为阴性;2例石蜡切片EGFR为阳性,而对应的细胞涂片为阴性,两种方法差异无统计学意义(P>0.05)。结论 FNA是术前诊断乳腺癌准确、易行的方法之一。浸润性乳腺癌术前FNA近似分子分型简单明了,切实可行。其有助于术前掌握乳腺癌的生物学特征,可能成为指导术前新辅助化疗、术式选择的有用指标。     

乳腺导管内癌分子分型应用研究

目的 采用免疫组织化学检测方法 对乳腺导管内癌进行分子分型.方法 收集50例乳腺导管内癌存档蜡块,用单克隆抗体CK5/6、CK8、CK18、34βE12、p63、S-100、SMA、CD10、CD117、EGFR、ER、PR和HER2进行免疫组织化学EnVision法染色,按照免疫表型分为5种类型:腺腔A型(ER+/PR+/HER2-)、腺腔B型(ER+/PR+/HER2+)、正常乳腺样型(ER-/PR-/HER2-且不表达基底/肌上皮标记及EGFR)、HER2过表达型(ER-/PR-/HER2+)和基底细胞样型(ER-/PR-/HER2-,且至少表达一种基底型角蛋白和(或)肌上皮标记物或EGFR).结果 腺腔A型16例(32%),腺腔B型19例(38%),HER2过表达型13例(26%),基底细胞样型2例(4%),无正常乳腺型.2例基底细胞样型,均表达CK5/6、CD117,例1同时表达SMA,例2表达CK8、CK18、34βE12、S-100,均为高级别导管内癌.结论 乳腺导管内癌可按免疫表型进行分子分型,部分导管内癌具有与基底细胞样癌相同的免疫表型,可能是基底细胞样癌的前驱病变,其诊断依赖于免疫组化检测.     

雄激素受体在乳腺癌中的表达及其与雌、孕激素受体和HER2的关系

目的 研究雄激素受体(AR)在乳腺浸润性导管癌中的表达及其与雌激素受体(ER)、孕激素受体(PR)和HER2状态的关系,探讨其作为乳腺癌治疗靶点的可行性.方法 采用免疫组织化学EnVision法检测AR、ER、PR、HER2在175例乳腺浸润性导管癌中的表达,依据结果分为腺腔A型、腺腔B型、HER2过表达型和三阴性型(ER-/PR-/HER2-)组.结果 175例中AR阳性88例(50.3%),AR表达与ER、PR、HER2均呈正相关(P＜0.01).腺腔A型53例(30.3%),腺腔B型33例(18.9%),HER2过表达型23例(13.1%),三阴性型66例(37.7%),AR阳性率分别为56.6%(30/53),75.8%(25/33)、47.8%(11/23)和33.3%(22/66),组间AR阳性率差异显著(x2=17.054,P=0.001).三阴性型组AR阳性者核分裂象较少(x2=5.140,P=0.023),腺腔A型组AR阳性者多为年轻患者(x2=4.567,P=0.033),差异有统计学意义.其他组内AR表达与否和临床病理学特征比较无统计学意义.结论 AR在乳腺癌中有较高的阳性率,可作为乳腺癌,特别是三阴性型乳腺癌的治疗靶点.     

雄激素受体在乳腺癌中的表达及其与雌、孕激素受体和HER2的关系

目的 研究雄激素受体(AR)在乳腺浸润性导管癌中的表达及其与雌激素受体(ER)、孕激素受体(PR)和HER2状态的关系,探讨其作为乳腺癌治疗靶点的可行性.方法 采用免疫组织化学EnVision法检测AR、ER、PR、HER2在175例乳腺浸润性导管癌中的表达,依据结果分为腺腔A型、腺腔B型、HER2过表达型和三阴性型(ER-/PR-/HER2-)组.结果 175例中AR阳性88例(50.3%),AR表达与ER、PR、HER2均呈正相关(P＜0.01).腺腔A型53例(30.3%),腺腔B型33例(18.9%),HER2过表达型23例(13.1%),三阴性型66例(37.7%),AR阳性率分别为56.6%(30/53),75.8%(25/33)、47.8%(11/23)和33.3%(22/66),组间AR阳性率差异显著(x2=17.054,P=0.001).三阴性型组AR阳性者核分裂象较少(x2=5.140,P=0.023),腺腔A型组AR阳性者多为年轻患者(x2=4.567,P=0.033),差异有统计学意义.其他组内AR表达与否和临床病理学特征比较无统计学意义.结论 AR在乳腺癌中有较高的阳性率,可作为乳腺癌,特别是三阴性型乳腺癌的治疗靶点.     

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.     

Germ-line mutations in BRCA1 or BRCA2 in the normal breast are associated with altered expression of estrogen-responsive proteins and the predominance of progesterone receptor A

The breast cancer susceptibility genes BRCA1 and BRCA2 are responsible for a large proportion of familial breast and ovarian cancer, yet little is known of how disruptions in the functions of the proteins these genes encode increased cancer risk preferentially in hormone-dependent tissue. There is no information on whether a germ-line mutation in BRCA1 or BRCA2 causes disruptions in hormone-signaling pathways in the normal breast. In this study markers of hormone responsiveness were measured in prophylactically removed normal breast tissue (n = 31) in women bearing a germ-line pathogenic mutation in one of the BRCA genes. The estrogen receptor (ER) and proteins associated with ER action in hormone-sensitive tissues, namely, PS2 and the progesterone receptor (PR), were detected immunohistochemically. ER expression was not different in BRCA mutation carriers than in noncarriers, but there was a reduction in PS2 expression. PR expression was also reduced, and there was a striking lack of expression of the PRB isoform, which resulted in cases with PRA-only expression in BRCA1 and BRCA2 mutation carriers. The alterations in PS2 and PR expression were similar in the BRCA1 and BRCA2 carriers, demonstrating that although these proteins are structurally and functionally distinct, there is overlap in their interaction with hormone-signaling pathways. This study provides evidence for altered cell function arising from loss of function of one BRCA allele in the normal breast, leading to PS2 loss, preferential PRB loss, and expression of PRA alone. In breast cancer development, PRA overexpression becomes evident in premalignant lesions and is associated with features of poor prognosis in invasive disease and altered cell function in vitro. The results of this study suggest that heterozygosity for a germ-line mutation in BRCA1 or BRCA2 results in development of PRA predominance. This is likely to lead to changes in progesterone signaling in hormone-dependent tissues, which may be a factor in the increased risk of cancer in these tissues in women with germ-line BRCA1 or BRCA2 mutations.     

乳腺癌易感基因1的表达与乳腺癌亚型关系的实验研究

目的 探讨乳腺癌易基因1（BRCA1）的表达与乳腺癌分子亚型的关系.方法 运用免疫组化法检测乳腺癌组织中BRCA1的表达与雌二醇受体（ER）和人表皮生长因子受体-2（Her-2）的关系,分析BRCA1的表达在乳腺癌各亚型中的意义.结果 ER阳性和阴性时,BRCA1的阳性率分别为40.2％和60.0％,表明BRCA1表达与ER有关（P＜0.05）,与Her-2无关（P＞0.05）.在乳腺癌各分子亚型中,Luminal B型和Her-2过表达型的BRCA1阳性率（66.7％和70.0％）与Basal-like型的BRCA1阳性率（75.0％）差别无统计学意义（P＞0.05）;Luminal A型的BRCA1阳性率（23.7％）低于Basal-like型的BRCA1阳性率（75.0％）,差别具有统计学意义（P＜0.05）.结论 BRCA1在Luminal B型、Her-2过表达型和Basal-like型乳腺癌中表达较高,在Luminal A型乳腺癌中表达不高,提示BRCA1可成为治疗乳腺癌的重要靶点.     

Prevalence of BRCA1 gene mutation in breast cancer patients in Guangxi,China

Objective: The prevalence of breast cancer susceptibility gene 1 mutation in breast cancer patients of south China has not been well revealed. This study was to invest the prevalence of BRCA1 gene mutation in breast cancer patients in Guangxi, China, and to try reflecting its relevance in genetic counseling of breast cancer. Methods: In this study, 463 breast cancer patients and 30 healthy women (control group) were involved. Entire sequence and splicing sites of BRCA1 genes were detected by PCR-DNA sequencing. Results: About 8.9% (41/463) patients were with 22 BRCA1 mutations (all in exon 10). The average hospitalized age of BRCA1-associated breast cancer cases was significantly younger (t = -2.965, P = 0.003). The nuclear grade (U = 2321.0, P = 0.030), ER (U = 4343.5, P = 0.041) and CerbB-2 (U = 3894.0, P = 0.038) expression levels, and triple negative breast cancer diagnosing rate (χ² = 4.719, P = 0.03) were disclosed more in BRCA1-associated patients. Conclusions: The four most frequent BRCA1 mutation (2798 T > C, 3971 G > A, 3971 G > A and 624 C > T) found in female breast cancer cases in Guangxi are all located in exon 10. BRCA1-associated breast cancer cases have earlier onset age, higher nuclear grade and negative ER and CerbB-2 expression.     

Loss of heterozygosity of p53, BRCA1, VHL,and estrogen receptor genes in breast carcinoma: correlation with related protein products and morphologic features

Correlation of loss of heterozygosity (LOH) of p53, BRCA1, VHL, and estrogen receptor (ER) genes with the expression of related protein products and morphologic features predictive of aggressive biologic behavior was investigated to determine the significance of LOH in these genes. DNA from 35 formalin-fixed, paraffin-embedded breast carcinomas was obtained by microdissection of histologic sections. LOH was determined by polymerase chain reaction (PCR) using primers TP53, D3S1038, D17S855, and ESR for p53, VHL, BRCA1, and ER genes, respectively. p53, ER, and progesterone receptor (PR) protein expression was evaluated by immunohistochemistry. Morphologic evaluation included histologic type, and histologic and nuclear grades. TP53 LOH was identified in 13 (52%), BRCA1 LOH in 3 (17%), VHL LOH in 1 (4%), and ER LOH in 4 (21%) of 25, 17, 24, and 19 informative cases, respectively. p53 and ER protein expression was identified in 20 (57%) and 25 (71%) cases, respectively. TP53 LOH directly correlated with both high histologic and nuclear grade (P<0.01). BRCA1, VHL, and ER LOH was not frequent enough for correlation to morphologic features. Although 4 of 4 ER and 7 of 13 p53 LOH cases expressed related proteins, LOH did not correlate with protein expression. TP53 LOH may be an event contributing to aggressive biologic behavior since it is strongly associated with high histologic and nuclear grade. Missense or nonsense mutations may explain the absence of detectable p53 protein in 6 of 13 cases with p53 LOH. All 4 ER LOH cases expressed ER protein. BRCA1 and VHL LOH is infrequent in sporadic breast carcinoma.     

Immunolocalization of BRCA1 protein in normal breast tissue and sporadic invasive ductal carcinomas: a correlation with other biological parameters

AIM: BRCA1, a nuclear phosphoprotein, normally functions as a negative regulator of the cell cycle and may be an active inhibitor of neoplastic progression. Mutation of the BRCA1 gene has been demonstrated in 80% of familial breast cancer. Decreased mRNA levels or aberrant subcellular locations of BRCA1 have been identified in breast cancer lines and in sporadic cases of breast cancer tissues. The expression of BRCA1 in large series of variously differentiated breast carcinomas with correlation with other biological parameters has not been clarified. METHODS AND RESULTS: The BRCA1 expression in normal breast tissue (n = 15) and in sporadic cases of invasive ductal carcinoma (n=108) was determined using immunohistochemistry. BRCA1 expression was correlated with other prognostic parameters including p53, c-erbB-2, bcl-2, oestrogen receptor (ER), histological grade, tumour size, axillary lymph node status and age. BRCA1 was exclusively (100%) localized in the nuclei of normal ductal and lobular epithelia. However, this nuclear expression pattern was variable in breast carcinoma (76.8%). Loss of nuclear BRCA1 expression (22 of 108 cases, 20.4%) correlated well with high histological grade (P<0.025) and bcl-2-negative tumours (P<0.05) and frequently in ER-negative tumours. CONCLUSION: BRCA1 nuclear expression could be considered to represent the normal or physiological phenotype. Complete loss of BRCA1 nuclear expression in breast cancer and its correlation with other poor prognostic markers suggest that BRCA1 expression may play an important role in the pathogenesis and prognosis of sporadic breast carcinoma. Altered BRCA1 phenotype may therefore provide an additional prognostic parameter for breast cancer.     

Vimentin and laminin expression is associated with basal-like phenotype in both sporadic and BRCA1-associated breast carcinomas

AIMS: To determine whether basal-like phenotype and vimentin and/or laminin are related in both sporadic/familial (BRCA1 or BRCA2 mutated) tumours. METHODS: 230 non-familial and 28 hereditary node-negative invasive breast carcinomas were immunohistochemically analysed for oestrogen receptors (ER), progesterone receptors (PR), cytokeratin 5/6 (CK5/6), epidermal growth factor receptors (EGFR), Ki67, p53, vimentin and laminin, using tissue microarrays. Tumours were considered to have basal-like phenotype if they were ER negative and HER2 negative, but positive for CK5/6 and/or EGFR. RESULTS: In sporadic tumours, vimentin expression was found in 77.8% cases with basal-like phenotype and 15.5% of non-basal cases (p<0.001). In familial cases, vimentin was expressed in 83.3% basal-like cancers and 16.7% of non-basal tumours (p<0.001). Vimentin expression was more frequent in BRCA1 than BRCA2 mutation carriers. Vimentin expressing tumours were associated with poor prognosis (p = 0.012) among patients not receiving adjuvant chemotherapy and showed a trend for local recurrence or visceral but not bone metastasis (p = 0.021). Laminin expression was also related to basal-like phenotype in both sporadic/familial cases (p<0.001 and p = 0.007, respectively), but neither with prognosis nor recurrence pattern in sporadic cancers. CONCLUSIONS: Vimentin and laminin expression is associated with basal-like phenotype in breast cancer. Expression of vimentin and laminin is characteristic of BRCA1 associated tumours. Since vimentin and laminin staining is widely used by pathologists for diagnostic purposes, thus demonstrating the robustness of their specific antibodies, the immunohistochemical evaluation of these two molecules could be used in identification of basal-like breast tumours in both sporadic/familial cases.     

BRCA1-methylated sporadic breast cancers are BRCA-like in showing a basal phenotype and absence of ER expression

BRCA1 mutations have been associated with hereditary breast cancer only. Recent studies indicate that a subgroup of sporadic breast cancer might also be associated with reduction in BRCA1 mRNA levels and protein expression. However, the mechanism of reduced mRNA and protein expression is yet not fully elucidated. This study aims to assess BRCA1 protein expression and the role of BRCA1 promoter methylation in sporadic breast cancer in North Indian population and to correlate these with known prognostic factors and molecular profiles of breast cancer. BRCA1 protein expression was normal (>50?% tumour cells) in 41 (43?%) cases, reduced (20-50?% tumour cells) in 33 (35?%) cases and absent/markedly reduced (<20?% tumour cells) in 21 (22.1?%) cases. Cases which were negative for BRCA1 protein were more frequently positive for basal markers (29 versus 5?%) and were more often ER-negative (62 versus 39?%) than BRCA1-positive tumours. Methylation of BRCA1 promoter region was seen in 11/45 cases (24?%). All 11 cases showing BRCA1 methylation had absent (eight cases) or reduced (three cases) BRCA1 protein expression. BRCA1 protein-negative tumours were more frequently basal marker-positive and ER-negative, highlighting the 'BRCAness' of sporadic breast cancer with loss of BRCA1 protein expression through promoter hypermethylation similar to hereditary breast cancer with BRCA1 mutations. Loss of BRCA1 in sporadic breast cancer suggests that therapeutics targeting BRCA1 pathway in hereditary breast cancer like PARP inhibitors might be used as therapeutic targets for sporadic breast tumours.     

Copy number profiling by array comparative genomic hybridization identifies frequently occurring BRCA2‐like male breast cancer

Genomic aberrations can be used to subtype breast cancer. In this study, we investigated DNA copy number (CN) profiles of 69 cases of male breast cancer (MBC) by array comparative genomic hybridization (aCGH) to detect recurrent gains and losses in comparison with female breast cancers (FBC). Further, we classified these profiles as BRCA1‐like, BRCA2‐like or non‐BRCA‐like profiles using previous classifiers derived from FBC, and correlated these profiles with pathological characteristics. We observed large CN gains on chromosome arms 1q, 5p, 8q, 10p, 16p, 17q, and chromosomes 20 and X. Large losses were seen on chromosomes/chromosome arms 1p, 6p, 8p, 9, 11q, 13, 14q, 16q, 17p, and 22. The pattern of gains and losses in estrogen receptor positive (ER+) MBC was largely similar to ER+ FBC, except for gains on chromosome X in MBC, which were uncommon in FBC. Out of 69 MBC patients, 15 patients (22%) had a BRCA2‐like profile, of which 2 (3%) were also BRCA1‐like. One patient (1%) was only BRCA1‐like; the remaining 53 (77%) patients were classified as non‐BRCA‐like. BRCA2‐like cases were more often p53 accumulated than non‐BRCA‐like cases (P = 0.014). In conclusion, the pattern of gains and losses in ER+ MBC was largely similar to that of its ER+ FBC counterpart, except for gains on chromosome X in MBC, which are uncommon in FBC. A significant proportion of MBC has a BRCA2‐like aCGH profile, pointing to a potentially hereditary nature, and indicating that they could benefit from a drug regimen targeting BRCA defects as in FBC. © 2015 Wiley Periodicals, Inc.     

The expression of ERCC1, RRM1, and BRCA1 in breast cancer according to the immunohistochemical phenotypes

We studied the expression of BRCA1, ERCC1, and RRM1 which play an important role in DNA repair systems in breast cancer. Immunohistochemical staining for EGFR, BRCA1, ERCC1, and RRM1 were performed by using a tissue microarray made from 230 breast cancer patients. Patients were classified into luminal A, luminal B, HER-2, and triple negative breast cancer (TNBC) types according to ER, PR, and HER-2 expression. The expression of ERCC1, RRM1, and BRCA1 were correlated (P < 0.05). The expression level of ERCC1 was the lowest in TNBC type (P = 0.031), ERCC1 negativity was more prominent in TNBC and luminal B groups than luminal A and HER-2 groups (P = 0.013). Cases with EGFR overexpression showed high expression of RRM1 and BRCA1 (P = 0.046, and 0.004, respectively). In conclusion, the expression of ERCC1 is particularly lower in TNBCs than other types of breast cancers.