不同ER、PR状态乳腺癌中AR的表达及其意义

目的探讨AR在不同ER、PR状态乳腺癌中的表达及意义。方法采用免疫组化方法检测AR、ER、PR在173例乳腺癌中的表达,依据结果分组:(1)AR状态分组:AR阳性组和AR阴性组;(2)ER、PR状态分组:En组(ER、PR均阴性)、Ep组[ER和(或)PR阳性];(3)AR、ER、PR联合分组:En-AR+(En组且AR阳性)、En-AR-(En组且AR阴性)、Ep-AR+(Ep组且AR阳性)、Ep-AR-(Ep组且AR阴性),其中En-AR-又称为均阴性组,其他三组统称为部分或完全阳性组。不同分组方法比较与临床病理特征的关系。结果Ep组AR阳性率62.8%(54/86),En组AR阳性率37.9%(33/87),两组差异有显著性(P=0.001),AR阳性组体积小、核分裂少、组织学分级低(P0.05);En-AR-组表现为核分裂多、组织学分级高(P0.01),此外En组内AR阳性者核分裂少、组织学分级低(P0.05),Ep组内AR阳性者临床分期高(P=0.000),En-AR+、Ep-AR+、Ep-AR-比较均无差异。结论AR在不同激素状态乳腺癌中表达的意义不同,ER、PR均阴性乳腺癌表达AR者预后较好,ER、PR阳性乳腺癌表达AR者临床分期高。在选择针对性药物时应考虑到不同激素受体状态的组合。     

Androgen receptor expression in ductal carcinoma in situ of the breast: relation to oestrogen and progesterone receptors

AIMS: Ductal carcinoma in situ (DCIS) of the breast has been diagnosed increasingly since the advent of mammographic screening. In contrast to the situation in invasive breast carcinoma, there are no reports on androgen receptor (AR) status in DCIS and few reports on oestrogen (ER) and progesterone (PR) receptors. METHODS: AR expression was examined in 57 cases of DCIS of the breast and correlated to the degree of differentiation and ER/PR status using immunohistochemical methods. RESULTS: AR positivity was noted in 19 of the cases, whereas the other 38 cases were negative. There was no significant association between AR expression and the degree of differentiation of DCIS; three of the 13 well differentiated DCIS cases, 10 of the 19 intermediately differentiated cases, and six of the 25 poorly differentiated cases were positive (p = 0.093). However, a strong association was shown between the expression of ER (p < 0.0001) and PR (p = 0.002) and the degree of differentiation of DCIS. In addition, no significant association was found between the expression of AR and the expression of ER (p = 0.26) or PR (p = 0.57) in DCIS of the breast. CONCLUSIONS: A large number of cases of DCIS of the breast express AR and this may be associated with apocrine differentiation, which may impact on accurate typing of DCIS. Moreover, the expression of AR (but not ER or PR) in DCIS does not appear to be associated with the degree of differentiation.     

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.     

Association between tumour characteristics and HER-2/neu by immunohistochemistry in 1362 women with primary operable breast cancer

AIMS: To investigate the association between tumour characteristics and HER-2/neu by immunohistochemistry in primary operable breast cancer. METHODS: The association between HER-2/neu and other clinicopathological factors was evaluated in 1362 consecutive patients with primary breast cancer treated between 2000 and July 2003 in one centre. Microscopic tumour size, tumour grade, lymph node status, patient's age, oestrogen receptor (ER), progesterone receptor (PR), and joint ER/PR status were evaluated, using the chi2 test for univariate analysis and logistic regression for multivariate analysis. The hormone receptors and HER-2/neu were studied immunohistochemically. Using the HER-2/neu DAKO scoring system, scores of 0, 1+, or 2+ were defined as negative and 3+ as positive. Data for DAKO scores 2+/3+ versus 0/1+ are also presented. RESULTS: Hormone receptor negative breast cancers were more often HER-2/neu positive than hormone receptor positive cancers, both for ER (28.7% v 6.8%) and PR (19.9% v 5.9%). In multivariate analysis, both ER, PR, and tumour grade were independently associated with HER-2/neu. In ER+ tumours, HER-2/neu overexpression was significantly lower in PR+ than in PR- cases (11.5% v 5.4%). HER-2/neu overexpression (2.7%) was lowest in the large subgroup of ER+PR+ tumours with low tumour grade (grade 1-2), comprising 46.1% of all patients. CONCLUSIONS: ER, PR, and tumour grade are independent predictors for HER-2/neu overexpression in women with primary operable breast cancer. ER and PR are negatively associated with HER-2/neu, whereas tumour grade is positively associated with HER-2/neu. In women with ER+ tumours, PR status also affects the likelihood of HER-2/neu expression.     

Evaluation of BrightGen HR RT-qDx assay to detect nuclear receptors mRNA overexpression in FFPE breast cancer tissue samples for selection of tamoxifen therapy

Breast cancer is a significant cause of death in women. Estrogen receptor (ER) and progesterone receptor (PR) are important prognostic factors indicating higher recovery rate in the breast cancer patients. Currently, immunohistochemical (IHC) staining is a conventional method to identify expression of ER and PR. If a breast cancer patient expresses ER or PR, a chemotherapy with estrogen inhibitors such as tamoxifen is supposed to be effective. Although IHC staining is a reliable method, it may not a useful method for continuous monitoring of ER and PR expression changes in multiple breast cancer patients. In the present study, we evaluated an alternative method of IHC for detection of ER and PR expression. A quantitative RT-PCR method called ‘the BrightGen HR RT-qDx assay’ was employed to detect mRNA expression of the nuclear receptors in 199 formalin-fixed paraffin-embedded (FFPE) breast cancer tissue samples. Among the ER/PR positive samples by IHC, 83 were determined positive and 16 were determined negative for the nuclear receptor mRNA by the quantitative RT-PCR method. Among the ER/PR negative samples by IHC, 37 were determined negative and 2 were determined positive by the quantitative RT-PCR method. The overall sensitivity and specificity of the quantitative RT-PCR method were 83.8% and 94.8% (P = 0.0026), respectively. We also optimized the quantitative RT-PCR method by setting up the diagnostic cut-off value using the likelihood ratio. The highest likelihood ratio was when the expression levels of the relative nuclear receptor mRNA passed 103.3 at which sensitivity and specificity was highest. These data suggest that BrightGen HR RT-qDx assay could be an alternative method for detection of the prognostic factors of nuclear receptors expressed in breast cancer patients for providing essential information for therapeutic application of tamoxifen.     

A study to determine the incidence of estrogen receptor (ER) and progesterone receptor (PR) expression in different histological grades of breast cancer

Abstract

Carcinoma of the breast is the most common non-skin malignancy in women and second most common cause of death due to cancer in females. Breast cancer is a heterogeneous disease with varied morphological appearances, molecular features, behavior, and response to therapy. This study was conducted with the aim of analysis of steroid receptor status in breast cancer and its association with other prognostic factors of breast cancer such as histological grade, tumor size, and axillary lymph node status. Fifty patients with the diagnosis of breast cancer were included in this study. Detailed clinical and histopathologic data were recorded in all cases. Estrogen receptor (ER) and progesterone receptor (PR) status was evaluated by immunohistochemistry. Histological grading was done with Nottingham modification of the Bloom and Richardson method. Fisher’s exact test and chi-square test was used for statistical analysis. On immunohistochemical staining, 44% cases proved to be ER positive and 48% cases PR positive. The results from the present study in India documented low ER and PR positivity in breast cancer in comparison to results from the western world. An inverse relation was found between hormone receptor (HR) status and histological grading, but no statistically significant relationship was noted between HR expression and tumor size and lymph node status.     

乳腺癌及癌前病变细胞DNA的定量分析及其与激素受体、癌胚抗原的关系

检测119例乳腺癌及40例癌旁增生性病变的DNA含量、类固醇激素受体(SR)和癌胚抗原(CEA)表达。结果显示:正常导管上皮、不同级别的癌旁增生上皮和癌细胞的DNA含量均有明显差异。多倍体的出现是细胞恶变的早期表现。癌细胞DNA含量与SR水平呈负相关,而与CEA表达呈正相关。SR阳性乳癌患者术后存活5年以上者DNA含量和核面积均小于5年内死亡者。     

Expression of steroid hormone receptors, their regulated proteins, and bcl-2 protein in myofibroblastoma of the breast

AIMS: To investigate the possible role of steroid hormones in the pathogenesis of myofibroblastoma (MFB) of the breast, we analysed the immunohistochemical expression of oestrogen, progesterone, androgen receptors, their regulated proteins and bcl-2 protein in a series of this rare tumour. METHODS AND RESULTS: Paraffin-embedded sections from seven cases of MFB of the breast (five male; two female) were immunohistochemically tested for the expression of oestrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR), oestrogen-regulated pS2 protein, androgen-regulated prostate-specific antigen (PSA) and bcl-2 protein. Rare cases of benign spindle cell tumours or tumour-like lesions of the breast (primitive fibromatosis, inflammatory pseudotumour, muscular hamartoma) which enter into the differential diagnosis with MFB, were also investigated and compared with MFB. All cases of MFB showed a diffuse (70-90% of neoplastic cells) and strong nuclear labelling with ER and PR, whereas AR was expressed only in three cases (two men and one woman) in about 60-70% of cells. Conversely, no immunostaining was detected for the pS2 protein and PSA. bcl-2 protein immunoreactivity was found in all cases of MFB, although with a variable degree of expression. No expression for steroid hormone receptors, their regulated-proteins and bcl-2 protein was observed in the rare benign spindle cell lesions of the breast included in this study. CONCLUSION: The in-situ detection of ER, PR and AR suggests that steroid hormones and their receptors are implicated in the pathogenesis of breast MFB. The consistent demonstration of bcl-2 protein, associated with a positive ER/PR status, provides evidence that bcl-2 may be an oestrogen-regulated protein also in MFB and that probably plays a role in the tumorigenesis. Finally, we postulate that the ER/PR and bcl-2 positive immunoprofile of MFB of the breast, in contrast to the negative profile of other rare primitive benign spindle cell lesions of the breast herein studied, might be exploited as an ancillary diagnostic aid in differential diagnosis of doubtful cases.     

Immunohistochemical expression of hormone receptors in invasive breast carcinoma: correlation of results of H-score with pathological parameters

The results of H-scores of oestrogen and progesterone receptor (ER and PR) expression in 150 invasive breast cancers were correlated with conventional pathological prognostic parameters: tumour size, histological grade and subtype, lymph node status, lymphovascular invasion, Nottingham Prognostic Index (NPI) and pathological stage. ER and PR status was determined by immunohistochemical staining of sections cut from archival paraffin-embedded tissue blocks. We defined positive receptor expression as a H-score of 50 and above. Our findings revealed ER and PR positivity in 98 (65%) and 52 (35%) cases, respectively. Fifty-one (34%) ER-positive cases also showed PR expression, while 51 (34%) tumours were negative for both ER and PR. Positive expression for ER and PR was significantly correlated with histological grade (P < 0.0005), mitotic score (P < 0.05) and nuclear pleomorphism (P < 0.05). When we used the relatively simpler method of a cut off of at least 10% tumour cell nuclear staining of moderate or greater intensity as positive receptor status, we found that it agreed well with results of the H-score, a more quantitative method of assessment.     

Estrogen receptor β– an independent prognostic marker in estrogen receptor α and progesterone receptor‐positive breast cancer?

Both subtypes of estrogen receptor (ER), ERα and ERβ, are normally present in the mammary gland. The role of ERα as a prognostic marker in breast cancer is well established due to the beneficial effect of providing tamoxifen as adjuvant therapy. The role of ERβ, however, is less clear. To gain insight into the importance of ERβ in breast cancer, 145 primary breast cancers were examined by immunohistochemistry for ERβ, and the expression level was compared with ERα and progesterone receptor (PR) status. Especially, we wanted to examine the significance of ERβ in the contrasting ERα+/PR+ and ERα?/PR? subgroups. In the ERα+/PR+ subgroup (dual positive), the survival difference between patients with low, medium and high ER β level was statistically significant (p = 0.004), with more than 70% of patients with medium and high ERβ levels surviving 100 months, compared with less than 30% in the group with low ERβ level. Further, for ERα+/PR+ patients there was a reduced risk of fatal outcome by multivariate analysis with increasing ERβ levels (p(trend) < 0.01 [univariate analysis]; p(trend) = 0.05 [multivariate analysis]). The risk was 31% and 27% for medium and high ERβ levels, respectively, compared with low ERβ level, adjusting for standard prognostic factors such as tumor diameter, nuclear tumor grade (quantified by mean nuclear area), lymph node status, and patient age at operation. For patients with ERα?/PR? tumors (dual negative), however, there was no association between ERβ levels and patient outcome. Our findings indicate that ERβ expression provides independent prognostic information for breast cancers with ERα/PR‐positive status, a feature typical among screen‐detected breast cancers. The role of ERβ needs to be further evaluated especially in this group of breast cancers.     

Expression of androgen receptor and two androgen-induced proteins (apolipoprotein D and pepsinogen C) in ductal carcinoma in situ of the breast

AIMS: To evaluate the expression of androgen receptors (AR) and two androgen-induced proteins [apolipoprotein D (ApoD) and pepsinogen C (PepC)] in ductal carcinoma in situ (DCIS) of the breast. METHODS AND RESULTS: AR, ApoD and PepC expression was examined in 28 cases of pure DCIS and in 31 cases of DCIS adjacent to invasive carcinoma of the breast using immunohistochemical methods and then correlated with the architectural subtype, the degree of differentiation and the ostrogen receptor (ER)/progesterone receptor (PgR)/HER-2 status. We found no significant differences between pure DCIS and DCIS adjacent to invasive breast cancer regarding the percentage of positive cases for ApoD (64.3% versus 54.8%), PepC (42.9% versus 48.4%), ER (64.3% versus 58.1%), PgR (60.7% versus 58.1%) and HER-2 (39.3% versus 67.7%). However, there was a significantly higher percentage of AR+ DCIS among those adjacent to invasive carcinomas of the breast than among pure DCIS lesions (93.5% versus 60.9%) (P = 0.009). AR expression did not correlate with architectural subtype, degree of differentiation, or ER/PgR/HER-2/ApoD/PepC status, in cases of pure DCIS, nor in DCIS adjacent to invasive carcinoma of the breast. CONCLUSIONS: AR expression may represent an independent predictive factor in DCIS of the breast.     

Trefoil Factor 1 in Early Breast Carcinoma: A Potential Indicator of Clinical Outcome during the First 3 Years of Follow-Up

Background. A role of an estrogen-regulated, autocrine motogenic factor was assumed to be a major biological role of trefoil factor 1 (TFF1) in breast cancer. TFF1 is regarded as a predictive factor for positive response to endocrine therapy in breast cancer patients. The aim of our study was to examine TFF1 level distribution in breast carcinomas in order to distinguish estrogen-independent from estrogen-dependent TFF1 expression and to evaluate clinical usefulness of TFF1 status in early breast cancer during the first 3 years of follow-up.Methods. The study included 226 patients with primary operable invasive early breast carcinomas for whom an equal, a 3-year follow-up was conducted. TFF1 levels as well as estrogen receptor (ER) and progesterone receptor (PR) levels were measured in cytosolic extracts of tumor samples by immunoradiometric assay or by use of classical biochemical method, respectively. Non-parametric statistical tests were applied for data analyses.Results. Statistical analysis revealed that TFF1 levels were significantly higher in premenopausal patients (p=0.02), or in tumors with: lower histological grade (p<0.001), positive ER or PR status (p<0.001, in both cases). On the basis of TFF1 level distribution between ER-negative and ER-positive postmenopausal patients with tumors of different histological grade, 14 ng/mg was set as the cut-off value to distinguish estrogen-independent from estrogen-dependent TFF1 expression in breast cancer. Depending on menopausal and PR status, positive TFF1 status identified patients at opposite risk for relapse among ER-positive patients with grade II tumors. Among ER- and PR-positive premenopausal patients with grade II tumors, TFF1 status alone identified patients at opposite risk for relapse.Conclusions. Determination of TFF1 status might identify patients at different risk for relapse and help in making decision on administering adjuvant therapy for early breast cancer patients during the first 3 years of follow-up.     

Relationship between the expression of various markers and prognostic factors in breast cancer

The immunohistochemical detection of six markers of breast cancer has been compared in the present study with known prognostic factors of the disease to establish locally a standard panel of markers for the management of breast cancer. Sections of tissue of 114 consecutive breast cancer cases were studied immunohistochemically, using antibodies against oestrogen receptor (ER), progesterone receptor (PR), androgen receptor, c-erbB2, cathepsin D, and cyclin D. Marker labelling was graded as recommended in the literature. Using the chi(2)-test, relationships were determined between marker labelling and histological type of cancer, tumour grade, tumour size, axillary lymph node status and age of patient. A p value below 0.05 was considered significant. A positive relationship was found between ER and PR and lower grades of cancer, and a negative relationship was found with medullary and atypical medullary carcinoma. The four other markers showed no relationship with grade or type of cancer. All markers showed no significant relationship with size of tumour, presence of axillary node metastasis or age of patient. There was positive correlation between c-erbB2 and cathepsin D. Our study confirms the association between ER and PR and histological type and grade of breast cancer, both known parameters of good prognosis. We found no consistent relationship between the other four markers and prognostic factors studied, other than the suggestion that c-erbB2 and cathepsin D may be useful markers for poor prognosis and can be usefully applied locally, especially in the light of the current availability of trastuzumab (Herceptin) for management of c-erbB2-positive cases. We found no relationship between the markers and tumour size, axillary lymph node status or age.     

Human milk fat globule antigen III D 5, steroid receptors and histopathologic parameters in breast cancer

Immunohistochemical reactivity of mammary carcinomas with the monoclonal human milk fat globule (HMFG) antibody III D 5, and the estrogen receptor (ER) and progesterone receptor (PR) status were compared with the histopathology of primary breast cancer. The reactivity with III D 5 has earlier been shown to be associated with the estrogen receptor status of tumours and with a favourable prognosis. The reactivity of tumours with III D 5, as well as the presence of ER and PR correlated significantly with the histological features of differentiation; histological grade, nuclear grade, tumour necrosis and lymphoid infiltration. Reactivity with III D 5 correlated with all these parameters, while the presence of ER did not correlate with the nuclear grade and that of PR correlated only with the nuclear grade and the lymphoid infiltration of tumours. Reactivity of III D 5 may thus have prognostic and therapeutic implications in the management of breast cancer.     

Breast cancer outcomes by steroid hormone receptor status assessed visually and by computer image analysis

Mohammed Z M A, Edwards J, Orange C, Mallon E, Doughty J C, McMillan D C & Going J J
(2012) Histopathology  61, 283–292 Breast cancer outcomes by steroid hormone receptor status assessed visually and by computer image analysis Aims: To compare the assessment of steroid hormone receptor immunohistochemistry by eye and by computer‐aided image analysis, and to examine their relationships with survival in breast cancer. Methods and results: Allred scores and weighted histoscores for oestrogen receptor (ER) and progesterone receptor (PR) immunohistochemistry were determined by eye (visual histoscore) for 459 primary invasive ductal breast carcinomas in triplicate tissue microarrays. Histoscores were also determined by computerized image analysis (automated histoscore). ER and PR status determined by these different methods were compared with each other and in their ability to predict survival over at least 142 months of follow‐up. Allred and visual histoscore were highly associated for ER and PR (both P < 0.001). By univariate analysis, Allred score and visual histoscore for ER and PR were highly associated with recurrence‐free and cancer‐specific survival (both P < 0.001) in patients with invasive ductal breast cancer overall, in those who received tamoxifen, and in those with recurrence on tamoxifen. Visual and automated histoscores were in excellent agreement for ER and PR (both P < 0.001), and were equally effective in predicting recurrence and survival for patients with invasive breast cancer who received tamoxifen. Conclusions: Automated histoscore appears to be a valid alternative to visual histoscore or Allred score for determining ER and PR status.     

Immunohistochemical characterization of molecular subtypes of invasive breast cancer: a study from North India

In recent years breast cancer has been classified on the basis of its molecular characteristics by gene expression profiling. A similar classification using immunohistochemistry has been identified so that it has a wider application. This study was designed to define the precise prevalence of molecular subtypes of invasive breast carcinoma using immunohistochemistry in patients from north India and to correlate it with known clinical and histological prognostic factors. Based on ER/PR/Her2/neu expression, 100 cases of invasive breast cancer were categorized into: ER+ and ? or PR+ and Her2/neu? (47%), ER+ and?or PR+ and Her2/neu+ (15%), ER? and ? or PR? and Her2/neu+ (Her2/neu overexpressing, 21%), ER?, PR? and Her2/neu? (Triple negative, 17%). All cases demonstrated positivity for the luminal Cytokeratins 8/18. In addition, 10% of these tumours showed expression of the basal markers (CK4/14, CK5/6). Among the 17 triple negative cases, eight cases were positive for one of the basal markers and two cases with basal marker expression were Her2/neu overexpressing. The basal markers showed significant correlations only with histological grade and ER negative status. On the basis of hormone receptor, Her‐2/neu and cytokeratin expressions, distinct subclasses of breast cancer have been identified which show significant differences in relation to histological grade and ER status. Expression of basal markers is needed to define basal‐like breast cancer.     

Androgen receptors are frequently expressed in mammary and extramammary Paget's disease.

Mammary Paget's disease and extramammary Paget's disease are rare intraepithelial neoplasms. Mammary Paget's disease is almost exclusively associated with underlying invasive breast carcinoma or high-grade ductal carcinoma in situ (DCIS G3). Extramammary Paget's disease arises in areas rich in apocrine glands and is suspected to have apocrine gland origin. The aim of the study was to investigate the presence of estrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR) and Her2/neu in a large number of cases. We investigated 58 cases of mammary and 23 cases of extramammary Paget's disease. Formalin-fixed and paraffin-embedded tissues were analyzed using antibodies against AR, PR, ER and Her2/neu according to standardized procedures. In mammary Paget's disease, positive immunoreactions for Her2/neu, AR and ER were observed in 56 of 58 (97%), 51 of 58 (88%), and respectively in six of 58 (10%) cases. All cases of mammary Paget's disease were negative for PR and showed a coexpression of Her2/neu and AR in 51 out of 58 cases (88%). In extramammary Paget's disease, positive immunoreactions for AR, Her2/neu and ER were observed in 18 of 23 (78%), 12 of 23 (52%), and respectively in 1 of 23 (4%) cases. All cases of extramammary Paget's disease were negative for PR and showed a coexpression of AR and Her2/neu in 12 out of 23 cases (52%). In contrast to ER and PR, AR and Her2/neu are commonly expressed in mammary and extramammary Paget's disease. The knowledge about frequent expression of AR in Paget's disease could lead to the development of a new adjuvant therapy, particularly in patients with recurrent disease.