乳腺癌患者新辅助化疗后ER、PR、HER2、Ki67表达变化及临床意义

目的:研究乳腺癌患者在新辅助化疗后ER、PR、HER2、Ki67的变化及临床意义。方法:选择2012年1月-2017年12月至我院进行乳腺癌新辅助化疗的患者176例进行临床研究。所有患者化疗前及术后行经B超引导下核芯针穿刺取病理活检,检测ER、PR、Ki67、HER2的表达,分析其变化情况。结果:176例乳腺癌患者新辅助化疗前ER阳性为57例,新辅助化疗后ER阳性为69例,新辅助化疗前ER阴性为119例,新辅助化疗后ER阴性107例;新辅助化疗前后状态改变了34例(19.32%),其中12例新辅助化疗前ER阴性转变为ER阳性,22例新辅助化疗前ER阳性转变为新辅助化疗后ER阴性,化疗前后患者ER表达变化有统计学差异(x~2=8.044,P=0.037);176例乳腺癌患者新辅助化疗前PR阳性为83例,新辅助化疗后PR阳性为89例,新辅助化疗前PR阴性为93例,新辅助化疗后PR阴性87例;新辅助化疗前后状态改变了82例(46.59%),其中45例新辅助化疗前PR阴性转变为PR阳性,37例新辅助化疗前PR阳性转变为新辅助化疗后PR阴性,化疗前后患者PR表达变化有统计学差异(x~2=6.311,P=0.049);176例乳腺癌患者新辅助化疗前HER2阳性为31例,新辅助化疗后HER2阳性为30例,新辅助化疗前HER2阴性为145例,新辅助化疗后HER2阴性146例;新辅助化疗前后状态改变了3例(1.70%),其中1例新辅助化疗前HER2阴性转变为HER2阳性,2例新辅助化疗前HER2阳性转变为新辅助化疗后HER2阴性,化疗前后患者HER2表达变化无统计学差异(x~2=0.522,P=0.945);176例乳腺癌患者新辅助化疗前Ki67阳性为104例,新辅助化疗后Ki67阳性为95例,新辅助化疗前Ki67阴性为72例,新辅助化疗后Ki67阴性81例;新辅助化疗前后状态改变了109例(61.93%),其中54例新辅助化疗前Ki67阴性转变为Ki67阳性,55例新辅助化疗前Ki67阳性转变为新辅助化疗后Ki67阴性,化疗前后患者Ki67表达变化有统计学差异(x~2=2.936,P=0.048),经过新辅助化疗后,Ki67出现上调表达最高,为23.86%,同时也是下调表达最高,为38.07%。HER2表达保持不变最高,为98.30%。结论:新辅助化疗会对乳腺癌患者ER、PR、Ki67的表达造成影响,其中对Ki67的影响最为显著。     

Clinical utility of determination of HER-2/neu and EGFR fragments in serum of patients with metastatic breast cancer

INTRODUCTION: The growth factor receptors EGFR and HER-2/neu are targets for new treatment strategies and are of potential use as prognostic and predictive factors. However, the optimal method of determination in order to obtain clinically relevant information remains a source of controversy. METHODS: HER-2/neu and EGFR expression was examined by immunohistochemistry in primary tumors of patients with breast cancer. In addition, serum was tested for the extracellular domains of HER-2/neu (HER-2/neu ECD) and EGFR (sEGFR) before initiation of therapy for metastatic disease (n=76). The course of disease from the time of metastasis with regard to these parameters was evaluated by univariate and multivariate analyses. RESULTS: HER-2/neu ECD levels at the time of metastatic disease were correlated with HER-2/neu expression determined by immunohistochemistry from primary tumors (p=0.001). No correlation was observed between expression of EGFR in primary tumors and sEGFR serum levels. HER-2/neu ECD and sEGFR levels at the onset of metastatic disease did not show a significant impact on overall survival. CONCLUSIONS: Determination of HER-2/neu ECD levels in the serum measured by ELISA at the onset of metastatic disease could offer an alternative to immunohistochemistry of the primary tumor since serum levels are correlated with protein expression in primary tumors. In contrast, no such correlation was observed for EGFR.     

Targeted therapy in breast cancer: the HER-2/neu gene and protein

The HER-2/neu oncogene, a member of the epidermal growth factor receptor or erb gene family, encodes a transmembrane tyrosine kinase receptor that has been linked to prognosis and response to therapy with the anti-HER-2-humanized monoclonal antibody, trastuzumab (Herceptin, Genentech, South San Francisco, CA) in patients with advanced metastatic breast cancer. HER-2/neu status has also been tested for its ability to predict the response of breast cancer to other therapies including hormonal therapies, topoisomerase inhibitors, and anthracyclines. This review includes an analysis of 80 published studies encompassing more than 25,000 patients designed to consider the relative advantages and disadvantages of the various methods of measuring HER-2/neu in clinical breast cancer specimens. Southern blotting, PCR amplification detection, and fluorescence in situ hybridization assays designed to detect HER-2/neu gene amplification are compared with HER-2/neu protein overexpression assays performed by immunohistochemical techniques applied to frozen and paraffin-embedded tissues and enzyme immunoassays performed on tumor cytosols. The significance of HER-2/neu overexpression in ductal carcinoma in situ and the HER-2/neu status in uncommon female breast conditions and male breast cancer are also considered. The role of HER-2/neu testing for the prediction of response to trastuzumab therapy in breast cancer is reviewed along with the current studies designed to test whether HER-2/neu status can predict the response to standard and newer hormonal therapies, cytotoxic chemotherapy, and radiation. The review will also evaluate the status of serum-based testing for circulating HER-2/neu receptor protein and its ability to predict disease outcome and therapy response.     

Quantitative assessment of HER-2/neu protein concentration in breast cancer by enzyme-linked immunosorbent assay

PURPOSE: The HER-2/neu protein (p185) has become a promising target for antibody therapy in breast cancer. We tested the feasibility of a quantitative approach for HER-2/neu testing based on the analysis of tumor tissue extracts by an enzyme-linked immunosorbent assay (ELISA). EXPERIMENTAL DESIGN: Tumor tissue extracts of primary human breast cancers (n=124) were prepared using a triton-based buffer. HER-2/neu concentration was quantified by ELISA. Paraffin-embedded tissue sections of the same tumors were analyzed by immunohistochemical staining applying the monoclonal HER-2/neu antibody TAB 250 (n=124) and by chromogenic in situ hybridization (CISH) (n=73). RESULTS: Concentrations of p185 in tissue extracts determined by ELISA varied from 1 to 927 ng per mg protein with a median of 25 ng/mg protein, whereas normal breast tissue showed values from 0.4 to 5.5 ng/mg with a median of 2.2 ng/mg (p<0.0001, Mann-Whitney U test). A significant correlation between p185 concentration and immunohistochemical staining was observed (p<0.0001, Kruskal-Wallis test). In addition, p185 concentration measured by ELISA was correlated with the degree of HER-2/neu gene amplification determined by CISH. HER-2/neu-amplified tumors had significantly higher p185 concentrations (median value 181 ng/mg protein) than non-amplified tumors (median value 20 ng/mg; p<0.0001, Mann-Whitney U test). CONCLUSIONS: ELISA-based measurement of HER-2/neu protein concentration in breast cancer tissue extracts is feasible and provides quantitative results for p185 protein concentrations that correlate closely with HER-2/neu immunoscore and gene amplification.     

HER-2/neu基因高表达及靶向治疗

HER-2/neu癌基因在许多肿瘤,如乳腺癌、卵巢癌、非小细胞肺癌等肿瘤中高表达,在肿瘤的发生与发展中起重要作用,与肿瘤的转化、转移、复发、预后差、患者生存期缩短有关。HER-2/neu在乳腺癌过度表达率约为20%～30%,编码蛋白P185HER2属生长因子受体家族,抗P185HER2单克隆抗体(Herceptin)作为靶向药物已临床应用治疗HER2/neu高表达乳腺癌。     

乳腺癌新辅助化疗的研究进展

乳腺癌是一种女性最常见的恶性肿瘤,近年来我国乳腺癌的发病率呈逐年上升趋势。研究证实,新辅助化疗不仅可使不能手术的晚期乳腺癌患者获得手术机会,而且也增加了部分患者的保乳概率,但是约20%的乳腺癌患者不能从新辅助化疗中获益,并影响后续治疗效果。因此,制定合理的、个体化的新辅助化疗方案对于提高乳腺癌患者的生存质量和改善其预后尤为重要。目前,研究已发现的NCT相关的预测因子主要包块肿瘤类型、分子分型、ER、PR、Ki67等,而HER2、TOP2A、P53、PRAP单独作为预测因子的还存在争议。本文主要对乳腺癌新辅助化疗的现状、各种预测因子的作用及其不足之处进行了综述。     

Inhibition of HER-2(neu/ErbB2) restores normal function and structure to polycystic kidney disease (PKD) epithelia

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a very common lethal monogenetic disease with significant morbidities and a high likelihood of progression to renal failure for which there is no proven disease-specific therapy currently available for clinical use. Human ADPKD cystic epithelia have proliferative abnormalities mediated by EGFR over-expression and mispolarization leading autocrine response to EGF family ligands. We now show that apical localization of EGFR complexes in normal fetal and ADPKD epithelia is associated with heterodimerization of EGFR(HER-1) with HER-2(neu/ErbB2), while basal membrane localization in normal adult renal epithelia is associated with EGFR(HER-1) homodimers. Since ADPKD epithelial cells have reduced migratory function, this was used as a bioassay to evaluate the ability of compounds to rescue the aberrant human ADPKD phenotype. General tyrosine kinase inhibition by herbimycin and specific inhibition of HER-2(neu/ErbB2) by AG825 or pretreatment with ErbB2 siRNA reversed the migration defect of ADPKD epithelia. Selective inhibition of EGFR(HER-1) showed partial rescue. Increased ADPKD cell migration after inhibition of p38MAP kinase but not of PI3-kinase implicated p38MAPK downstream of HER-2(neu/ErbB2) stimulation. Daily administration of AG825 to PKD1 null heterozygous mice significantly inhibited the development of renal cysts. These studies implicate HER2(neu/ErbB2) as an effector of apical EGFR complex mispolarization and that its inhibition should be considered a candidate for clinical therapy of ADPKD.     

Downregulation of wild-type p53 protein by HER-2／neu mediated PI3K pathway activation in human breast cancer cells： its effect on cell proliferation and implication for therapy

Overexpression and activation of HER-2/neu (also known as c-erbB-2), a proto-oncogene, was found in about 30% of human breast cancers, promoting cancer growth and making cancer cells resistant to chemo- and radio-therapy.Wild-type p53 is crucial in regulating cell growth and apoptosis and is found to be mutated or deleted in 60-70% of human cancers. And some cancers with a wild-type p53 do not have normal p53 function, suggesting that it is implicated in a complex process regulated by many factors. In the present study, we showed that the overexpression of HER-2/neu could decrease the amount of wild-type p53 protein via activating PI3K pathway, as well as inducing MDM2 nuclear translocation in MCF7 human breast cancer cells. Blockage of PI3K pathway with its specific inhibitor LY294002 caused G1-S phase arrest, decreased cell growth rate and increased chemo- and radio-therapeutic sensitivity in MCF7 cells expressing wild-type p53. However, it did not increase the sensitivity to adriamycin in MDA-MB-453 breast cancer cells containing mutant p53. Our study indicates that blocking PI3K pathway activation mediated by HER-2/neu overexpression may be useful in the treatment of breast tumors with HER-2/neu overexpression and wild-type p53.     

Expression of HER2/neu is uncommon in human neuroblastic tumors and is unrelated to tumor progression

Neuroblastic tumors (NT) are the most frequently occurring extracranial solid tumors during childhood. The overall 5-year survival is approximately 20% for patients with metastatic disease. Novel treatments are therefore intensively sought and tumor-targeted immuno- and chemotherapy appear promising. The HER2/neu oncogene, which is highly homologous to the EGF receptor, was initially isolated from rat neuroblastoma cells. HER2/neu over-expression is frequently detected in breast tumors and constitutes an important unfavorable prognostic factor. HER2/neu is a suitable target for antibody-based immunotherapy, as demonstrated by the clinical efficacy of the Herceptin monoclonal antibody (mAb), which reacts with its extracellular domain. Expression of HER2/neu has also been reported to be a negative prognostic factor in a small survey of NT tumors. Here, we have investigated HER2/neu expression in 14 human and 2 murine neuroblastoma (NB) cell lines by flow cytometric analysis and in 93 NT by means of a certified immunohistochemical system. HER2/neu over-expression was found in 2 human cell lines and 11 tumors (14% for both types of samples). No significant association was found between HER2/neu expression and stage, age, sex, ploidy, histological type or subtype. Moreover, log rank test indicated that overall and event-free survival was not significantly different in HER2/neu positive and negative patients. These data suggest that HER2/neu should not be considered as a relevant prognostic factor in NT, and that HER2/neu-based immunotherapy may be feasible only in a minority of NT patients.     

Progesterone receptor inhibits aromatase and inflammatory response pathways in breast cancer cells via ligand-dependent and ligand-independent mechanisms

Aromatase (product of CYP19 gene), the critical enzyme in estrogen biosynthesis, is up-regulated in 70% of all breast cancers and is highly correlated with cyclooxygenase 2 (COX-2), the rate-determining enzyme in prostanoid biosynthesis. Expression of COX-2 also is correlated with the oncogene HER-2/neu. The efficacy of current endocrine therapies for breast cancer is predicted only if the tumor contains significant amounts of estrogen receptor. Because the progesterone receptor (PR) is an estrogen-induced target gene, it has been suggested that its presence may serve as an indicator of estrogen receptor functional capacity and the differentiation state of the tumor. In the present study, we tested the hypothesis that PR serves a crucial protective role by antagonizing inflammatory response pathways in the breast. We observed that progesterone antagonized the stimulatory effects of cAMP and IL-1beta on aromatase, COX-2, and HER-2/neu expression in T47D breast cancer cells. These actions of progesterone were associated with increased expression of the nuclear factor-kappaB inhibitor, IkappaBalpha. In 28 breast cancer cell lines, IkappaBalpha expression was positively correlated with PR mRNA levels; overexpression of a phosphorylation-defective mutant of IkappaBalpha inhibited expression of aromatase, COX-2, and HER-2/neu. Moreover, in breast cancer cell lines cultured in the absence of progesterone, up-regulation of endogenous PR caused decreased expression of aromatase, COX-2, and HER-2/neu expression, whereas down-regulation of endogenous PR resulted in a marked induction of aromatase and HER-2/neu mRNA. Collectively, these findings suggest that PR plays an important antiinflammatory role in breast cancer cells via ligand-dependent and ligand-independent mechanisms.     

Isolation of scFv antibody fragments against HER2 and CEA tumor antigens from combinatorial antibody libraries derived from cancer patients

Tumor cells expressing HER-2/neu and CEA antigens are potentially ideal targets for antibody-targeted therapy. In this study, two large human combinatorial libraries have been generated from the lymph nodes of breast cancer patients that express HER2 and CEA antigens in their tumors. These ‘immune’ libraries have been constructed in two different formats of scFv, differing in the length of the peptide linker connecting the two variable VH and VL domains. Libraries derived from these patients may contain a larger pool of anti-tumor antigen antibodies and are useful repertoire for isolating scFvs against any tumor markers. The results of this study showed that we were successful in obtaining human scFvs against HER-2/neu and CEA. For HER-2, cell-panning strategy was performed and resulted in two scFv binders that detected the complete HER-2 receptor on the cell membrane and internalized to the cells. Also, preliminary ELISA data showed that several anti-CEA scFv binders were isolated by panning.     

Intratumor heterogeneity of biomarker expression in breast carcinomas

Small biopsy samples are used increasingly to assess the biomarker expression for prognostic information and for monitoring therapeutic responses prior to and during neoadjuvant therapy. The issue of intratumor heterogeneity of expression of biomarkers, however, has raised questions about the validity of the assessment of biomarker expression based on limited tissue samples. We examined immunohistochemically the expression of HER-2neu (p185^erbB-2), epidermal growth factor receptor (EGFR), Bcl-2, p53, and proliferating cell nuclear antigen (PCNA) in 30 breast carcinomas using archived, paraffin embedded tissue and determined the extent of intratumor heterogeneity. Each section was divided into four randomly oriented discrete regions, each containing a portion of the infiltrating carcinoma. For each tumor, the entire lesion and four regions were analyzed for the expression of these markers. Scores of both membrane and cytoplasmic staining of HER-2neu and EGFR, scores of cytoplasmic staining of Bcl-2, and scores of nuclear staining of both p53 and PCNA were recorded. The intensity of staining and the proportion of immunostained cells were determined. A semiquantitative immunoscore was calculated by determining the sum of the products of the intensity and corresponding proportion of stained tumor cells. We analyzed both invasive (IDC) and in situ (DCIS) carcinomas. The Wilcoxon signed-rank test was used for paired comparisons between overall and regional immunoscores and between overall and regional percentages of stained cells. Spearman's correlation coefficients were used to assess the level of agreement of overall biomarker expression with each of the regions. Generalized linear models were used to assess overall and pair-wise differences in the absolute values of percent changes between overall and regional expression of biomarkers. For IDCs, there were no statistically significant differences in the expression of the biomarkers in terms of either the percentage of cells staining or the immunoscores when comparing the entire tumor with each region except for the lower EGFR expression of arbitrarily selected region 1 and lower p53 expression of region 1 compared to that of the entire tumor section. For DCIS, there were no statistically significant differences in the expression of the biomarkers between the entire tumor and each region except in PCNA of region 2 compared to that of entire tumor section. Positive correlation of immunoscores was observed between the entire tumor and each region as well as across all four regions for IDC. Similar observations were noted with DCIS except for HER-2neu and PCNA. No statistically significant differences were observed in the absolute values of percent changes of biomarker expression between overall and the four regions for both DCIS and IDC. Therefore, no significant intratumor heterogeneity in the expression of HER-2neu, Bcl-2, and PCNA was observed in IDC. Minor regional variations were observed for EGFR and p53 in IDC. Similarly, no significant regional variation in the expression of markers was observed in DCIS except for PCNA.     

Evaluation of HER-2/neu in serum and tissue of primary and metastatic breast cancer patients using an automated enzyme immunoassay

Serum HER-2/neu concentrations were evaluated in 172 healthy subjects, 176 primary and 55 metastatic breast cancer patients, employing a new automated assay (Bayer Immuno 1 serum HER-2/neu). Using 13 ng/mL as the cutoff, abnormal HER-2/neu serum levels were found in 8% (14/176) of primary and 50.9% (28/55) of metastatic breast cancer patients. Both in primary and metastatic breast cancer a significant relationship was found with the stage of the disease when serum HER-2/neu was considered as a categorized variable (p=0.0003 and p=0.02, respectively), but not when it was taken as a continuous variable (p=0.247 and p=0.146, respectively). Moreover, we evaluated the correlation between Immuno 1 HER-2/neu and Oncogene Research Products ELISA assay in 53 normal subjects, 46 primary and 34 metastatic breast cancer patients. The correlation was relatively good (p<0.0001), although substantial differences could be found in single cases. The Immuno 1 assay was also evaluated for the first time in breast cancer tissue. The method, which showed good performance both in terms of imprecision and linearity, was used to measure HER-2/neu protein in 140 cytosol samples from primary breast cancer tissue and in homogenates from 40 matched cases. The correlation between the two matrixes was very close (p<0.0001). By contrast, no correlation was found between serum and matched cytosol (p=0.101) or homogenate samples (p=0.511).     

Metformin extends life span of HER-2/neu transgenic mice and in combination with melatonin inhibits growth of transplantable tumors in vivo

Population studies have shown that treatment with the antidiabetic biguanide metformin significantly reduced cancer risk. In our animal studies, metformin delayed the onset of mammary adenocarcinoma (MAC) in transgenic HER-2/neu mice but not the onset of spontaneous mammary tumors in female SHR mice. Pineal hormone also inhibits mammary carcinoma development in HER2/neu transgenic mice as well as in female SHR mice. Here we demonstrated that a combination of metformin and melatonin significantly inhibits growth of transplanted tumors in mice. Metformin (1.2 mg/ml in drinking water) increased mean life span by 8% and MAC latency by 13.2% (p     

Discordant results obtained for different methods of HER-2/neu testing in breast cancer--a question of standardization, automation and timing

BACKGROUND: HER-2/neu positivity is required for the selection of stage IV breast cancer patients for trastuzumab therapy. We compared the results of the recommended immunohistochemistry (IHC) evaluation with the automated ACIS IHC system and with fluorescence in situ hybridization (FISH). These HER-2/neu tissue results were correlated with the serum HER-2/neu (sHER-2/neu) levels at the time of metastatic spread. PATIENTS AND METHODS: A total of 61 IHC slides from 30 patients were stained using the HercepTest. HER-2/neu gene amplification was determined using the Ventana FISH assay. sHER-2/neu levels were measured with the Oncogene Science" ELISA kit. The concordance of HER-2/neu results was determined using the concordance index Kappa (kappa). RESULTS: The best concordance between any IHC and FISH was found for the automated ACIS system (88.5%, kappa=0.68, category "good"). The comparison between the manual interpretations and the automated IHC was categorized as "very good" (95.1%, kappa=0.85). The median sHER-2/neu level of FISH positive patients was significantly higher (67 ng/mL) than that of FISH negative patients (17 ng/mL, p=0.018). The increase in HER-2/neu positivity comparing tissue to stage IV serum was statistically significant (p=0.001). CONCLUSIONS: The concordance between conventional IHC and computerized analysis was very good. The number of patients with stage IV breast cancer with an elevated sHER-2/neu level was much higher than HER-2/neu positivity in tissue. This discrepancy is only partially explained by the influence of tumor load. Patients with an elevated sHER-2/neu level and no tissue overexpression should be considered for retesting of tissue or a new biopsy.     

Breast infiltrating ductal carcinoma: analysis of hormone, HER-2 receptors and Ki-67 proliferation marker

The aim of this study was to analyse breast carcinomas with discordant receptor status, probably hormonal dependent (estrogen receptor (ER) positive, progesterone receptor (PR) negative or ER-PR + subgroup profile) infiltrating ductal breast carcinomas not otherwise specified (IDC NOS). Specimens from 90 IDC NOS were grouped into three categories according to hormonal status: dependent (D) (ER +PR +), probably dependent (PD) (ER +PR- or ER-PR +) and non-dependent (ND) (ER-PR-); they were evaluated considering some established prognostic parameters in breast carcinomas. Statistically significant difference was found between tumor receptor status distribution and menopausal status (p = 0.0235), age of the patients (p = 0.000467), histological grade (p = 0.000003), vascular invasion (p = 0.006), HER-2 status (p = 0.0039) and Ki-67 proliferation rate (p = 0.000311). D tumors were found exclusively in post-menopausal patients (average age 68.9 years), most of which had intermediate (II) grade, without vascular invasion, with HER-2 status score predominantly 0 or 1 + and lower Ki-67 proliferation rate. PD tumors were found predominantly in younger post-menopausal patients (average age 57.5 years), with vascular invasion found in 23% of the cases. ND tumors mostly had higher histological grade, showed the highest percentage of the Ki-67 positive tumor cells and vascular invasion in 30% of the cases. We conclude that the patients with PD breast carcinomas were younger post-menopausal women with the tumors moderately differentiated, HER-2 score 0 or 1+ and with lower Ki-67 proliferation rate.     

Timely DNA vaccine combined with systemic IL-12 prevents parotid carcinomas before a dominant-negative p53 makes their growth independent of HER-2/neu expression

Double transgenic mice overexpressing the transforming rat HER-2/neu oncogene and the mutated p53, with both dominant-negative and a gain-of-function properties, display early aggressive and metastasizing parotid tumors. Multiple acinar and ductal hyperplasia foci overexpressing the HER-2/neu gene product are evident at wk 5 and progress to poorly differentiated carcinoma by wk 7. Mice die before wk 18 with invasive carcinomas and multiple metastases that no longer express HER-2/neu. A combination of repeated electroporations of plasmids coding for the extracellular and transmembrane domains of the rat HER-2/neu receptor with systemic IL-12 administrations started when the parotids that present diffuse hyperplasia protected all female and 50% of the male mice until the close of the experiment at wk 40. This combined treatment began when multifocal in situ carcinomas that were already present cured 33% of the females and 25% of the males. The most prominent immunologic features associated with the antitumor protection were the production of high titers of anti-HER-2/neu Abs and the nonappearance of cell-mediated cytotoxic reactivity. In conclusion, anti-HER-2/neu vaccination combined with systemic IL-12 control parotid carcinomas as far as p53 mutation makes their growth independent of HER-2/neu expression.     

HER-2/neu evaluation by fluorescence in situ hybridization on destained cytologic smears from primary and metastatic breast cancer

OBJECTIVE: To evaluate HER-2/neu amplification by fluorescence in situ hybridization (FISH) (HER-2/neu by FISH) on archival cytologic smears stained with May-Grünwald-Giemsa (MGG) stain. STUDY DESIGN: Cytologic specimens from 69 breast cancer lesions (48 primary and 21 metastatic), stained with MGG stain for routine diagnostic cytology, were destained and subjected to HER-2/neu by FISH. Fifteen of the 69 samples were also evaluated by FISH on paired fresh smears. RESULTS: HER-2/neu by FISH was successfully assayed in 25 of the 48 primary tumors and in 15 of the 21 metastatic lesions, corresponding to an overall feasibility of 58%. These cases had been archived between 1 month and 10 years prior to FISH analysis. Eight of the 25 primary and 5 of the 15 metastatic tumors were amplified. In 15 of the 40 evaluable cases, HER-2/neu was also assessed on the corresponding fresh smears: 8 tumors were amplified and 7 unamplified on both destained MGG and fresh smears. CONCLUSION: HER-2/neu can be detected by FISH on routinely MGG-stained cytologic slides. This approach allows HER-2/neu evaluation whenever histologic sections or fresh cytologic material are not available. In these cases, HER-2/neu assessment on destained cytologic smears plays a role in the selection of targeted therapy.