Neu Oncogene Expression Research Articles

A Double-blind Randomized Comparative Phase I Study to Assess Biosimilarity and Immunogenicity of "Trastuzumab" (LLC "Mabscale", Russia) and Herceptin® (F. Hoffmann-La Roche Ltd., Switzerland) in Healthy Volunteers

Introduction. Trastuzumab is the first drug based on the monoclonal antibodies’ technology targeted to the neu oncogene expression product discovered in the middle 80-s – human epidermal growth receptor, HER2. After being approved trastuzumab had become the drug of choice for combine therapy of metastatic breast cancer (BC). This therapy had also allowed to improve patients’ 5-year survival rate dramatically, almost up to 90 % in some cases. Despite the fact that more than 10 biosimilars of trastuzumab are now in the pipeline around the world, including Russia, the development and registration of trastuzumab biosimilars still remain relevant.Aim. Aim of the study was to conduct the analytical part of the double-blind randomized comparative clinical trial for trastuzumab pharmacokinetics and safety assessment in healthy volunteers with subsequent biosimilarity evaluation of "Trastuzumab" (LLC "Mabscale", Russia) and Herceptin® (F. Hoffmann-La Roche Ltd., Switzerland).Materials and methods. 92 healthy volunteers, who fulfilled the inclusion/exclusion criteria, were enrolled to the study. Trastuzumab quantitation and anti-trastuzumab antibodies detection was performed using ELISA method with photometric detection. To support the clinical trial two different independent bioanalytical methods were validated.Results and discussion. Trastuzumab quantitation method in human blood serum was validated for selectivity, calibration curve and regression model, sensitivity (LLOQ), accuracy and precision, MRD, dilution linearity and stability. The method for anti-trastuzumab antibodies detection, that was previously described by the authors, was validated for cut-point, selectivity, sensitivity, prozone effect, drug tolerance, precision and stability (short-term and long-term). The validated methods were successfully applied to the study samples assay to perform the analytical part of the comparative study for trastuzumab pharmacokinetics and immunogenicity assessment. The obtained drug concentrations were used for PK-parameters and confidence interval calculations to estimate the biosimilarity of test and reference drug.Conclusion. The study results showed that test and reference drug are biosimilar, and moreover immunogenicity assessment showed no anti-trastuzumab antibodies in any samples of healthy volunteers.

A study of Her-2/Neu oncogene expression in benign and malignant endometrial lesions and its association with clinicopathologic variables

Introduction: Endometrial carcinoma is commonly diagnosed gynaecological malignancy in women and the incidence of endometrial cancer and associated mortality rates have increased in recent years. Endometrial hyperplasia is recognized precursor lesion of endometrial cancer and its timely detection offers an opportunity to prevent the development of endometrial cancer. Her-2/neu oncogene amplification has been implicated in the development and progression of many tumours and its overexpression may be involved in tumorigenesis of endometrial carcinoma as well. The present study was aimed to evaluate Immunohistochemical (IHC) expression of Her-2/neu oncogene in Benign and Malignant Endometrial Lesions and its correlation with clinicopathological features in order to define its potential prognostic significance. Material and Methods : A total of 62 cases including 20 cases of endometrial hyperplasia and 42 cases of Endometrial Carcinoma were enrolled in the study. Clinical and pathologic information was obtained and recorded. Her-2/neu expression was evaluated by immunohistochemistry (IHC) on paraffin embedded tissue sections with Her-2/neu antibody. Overexpression was defined as complete, membrane, moderate to strong intensity staining in greater than 10% of cells. Results: Positive HER-2/neu expression is seen in 45% cases of Endometrial Hyperplasia and in 54.76% cases of endometrial carcinoma. The Her-2/neu overexpression was observed in patients with advanced stage (p Conclusion: In the present study Abnormal high Her-2/neu expression was observed in Endometrial carcinoma, correlating with High FIGO stage, high grade, lymph node metastasis, myometrial invasion and cervical invasion, indicating Her-2/neu expression analysis could be an important prognostic factor of Endometrial carcinoma. Keywords: Endometrial carcinoma, Endometrial Hyperplasia, HER­2/neu, prognostic factor

New insights into oncogenic stress

Expression of oncogenes in otherwise normal cells often leads to the activation of anti-oncogenic pathways through a poorly understood process described as 'oncogenic stress'. A new study implicates the Jnk pathway signaling in the activation of p53 in response to both K-Ras and Neu oncogene expression.

γ- and δ-tocotrienols exert a more potent anticancer effect than α-tocopheryl succinate on breast cancer cell lines irrespective of HER-2/neu expression

Aims Breast cancer is the most common malignancy among women, with an age-specific incidence profile. During the last years much evidence has accumulated demonstrating the anticancer activity of tocotrienols (T3), a subfamily of natural vitamin E (VE). In this study, mouse and human breast cancer cells (with or without HER-2/neu oncogene overexpression) were used to investigate the anticancer effect of α-, γ-, and δ-tocotrienols in comparison with α-tocopheryl succinate (α-TOS), a synthetic derivative with widely recognized anticancer properties. Main methods Human and mouse breast cancer cell lines were used. The effect of VE compounds on cell viability was investigated using Alamar Blue assay. Apoptosis was assessed by propidium iodide and JC-1 staining. Expression of senescence-associated markers was evaluated by RT-PCR and Western blot analysis was used to examine the changes in the expression levels of HER-2/neu. Key findings γ- and δ-Τ3 reduced cell viability with IC 50 values of less than half those of α-T3 and α-TOS. γ- and δ-Τ3, and α-TOS to a lesser extent, induced apoptosis possibly via the mitochondrial pathway, and the expression of senescent-like growth arrest markers as p53, p21, and p16. Both α-TOS and tocotrienols downregulated HER-2/neu in tumor cells overexpressing this oncogene, but this effect did not seem to be essential for the antitumor activity of these compounds. Significance We demonstrate that in HER-2/neu breast cancer cells, the non-alpha form of T3 shows stronger anticancer activity than the synthetic VE-derivative α-TOS and this effect occurs independently from the inhibition of HER-2/neu oncogene expression.

Choline as a biomarker for cell proliferation: Do the results from proton MR spectroscopy show difference between HER2/neu positive and negative breast cancers?

Choline as a biomarker for cell proliferation: Do the results from proton MR spectroscopy show difference between HER2/neu positive and negative breast cancers?

Plasma total antioxidant status in breast cancer women in relation to lymph node involvement and HER-2/neu expression

Summary Background Oxidants can act at several stages of malignant transformation. To protect against toxic effects of oxidants and to modulate physiological effects of their action organisms have developed antioxidant defence systems. Plasma total antioxidant activity (TAS) measures peroxyl-scavenging capacity of the extracellular antioxidant system. Aim The goal of this pilot study was to evaluate the plasma total antioxidant status in breast cancer women in relation to lymph node metastases and HER-2/neu expression. Materials/Methods Newly diagnosed consecutive breast cancer patients (n=26) were recruited before any treatment and matched with controls (n=24) randomly selected from benign breast disease patients. Cancer progress was established according to lymph node involvement: No or N+. HER-2/neu was considered as either negative (0 or 1+) or positive (2+ or 3+). The plasma total antioxidant status (TAS) was measured by colorimetric test (RANDOX). HER-2/neu oncogene expression was determined in breast cancer tissue using the immunohistochemical method (Hercep Test). Results The study demonstrated a significant decrease in the mean TAS level (mmol/L) in the breast cancer group (1.42±0.22) in comparison to the control group (1.56±0.18; P Conclusions The results of the study suggest increased consumption of plasma antioxidants in response to enhanced oxidants production in breast cancer patients. Changes in TAS level do not seem to correspond with the progress of the malignancy but might be related to HER-2/neu expression.

Human manganese superoxide dismutase suppresses HER2/neu-mediated breast cancer malignancy

The up-regulation of HER2/neu is associated with human malignancies and is a useful target for developing anticancer drugs. Overexpression of human manganese superoxide dismutase (MnSOD) has been demonstrated to effectively suppress various carcinoma cells, including breast carcinomas, in vitro and in vivo. This study demonstrates that MnSOD effectively suppresses HER2/ neu oncogene expression at the transcriptional level. Additionally, stable transfection was used and the MnSOD-transfected human breast cancer clones were found to be able to down-regulate the endogenous production of p185 HER2/neu. Furthermore, the MnSOD-overexpressing stable transfectants exhibited reduced soft-agarose colony-forming ability and metastatic properties, unlike control cell lines. These data suggest that MnSOD may be useful in treating HER2/neu-mediated human breast tumor malignancy.

Overexpression of HER-2/neu oncogene and transitional cell carcinoma of bladder.

The aim of this study was to evaluate the relationship between HER-2/neu oncogene expression and grade of transitional cell carcinoma (TCC) of the bladder. In this cross-sectional study, 75 formalin-fixed paraffin-embedded specimens of primary TCC of the bladder were stained with a monoclonal antibody against HER-2/neu oncoprotein. Another section was stained by hematoxylin-eosin and the tumor grade was determined according to the World Health Organization/International Society of Urological Pathologists criteria. Tumor specimens belonged to 49 men (65.3%) and 26 women (34.7%) with a mean age of 56.3 +/- 9.1 years (range, 39 to 80 years). The tumor grades were 1, 2, and 3 in 14 (18.7%), 35 (46.7%), and 26 (34.7%) specimens, respectively. A total of 28 (37.3%) patients were positive for overexpression of HER-2/neu. There were 1 case of HER-2/neu-positive (7.1%) with a grade 1 tumor, 10 (28.6%) with grade 2, and 17 (65.4%) with grade 3; a significant relationship between HER-2/neu overexpression and grade of the bladder TCC tumors was found (P = .002). Expression of HER-2/neu oncogene has a direct relationship with the grade of the bladder TCC. Further studies with longer follow-up period and a larger sample size can determine the probable role of HER-2/neu expression as a prognostic factor in the TCC of bladder.

Application of chromogenic in-situ hybridization in detecting HER-2/neu oncogene expression in breast carcinoma and its significance

对于检测常规甲醛固定的乳腺癌石蜡组织切片中HER-2/neu原癌基因的核苷酸序列技术方法而言,荧光原位杂交法(FISH)一直是公认比较敏感和经典的检测方法[1-3].而显色原位杂交法(chromogenic in situ hybridization,CISH)作为一种核酸原位分子杂交技术方法,也可用于常规甲醛固定的乳腺癌石蜡组织切片中的HER-2/neu原癌基因的检测[4,5]。

Exogenous supplementation with ω-3 polyunsaturated fatty acid docosahexaenoic acid (DHA; 22:6n-3) synergistically enhances taxane cytotoxicity and downregulates Her-2/neu (c-erbB-2) oncogene expression in human breast cancer cells

Omega-3 polyunsaturated fatty acid (PUFA), docosahexaenoic acid (DHA; 22:6n-3) and other omega-3 and omega-6 PUFAs have raised interest as novel anticancer agents by exerting selective cytotoxic effects on human cancer cells without affecting normal tissues. Here, we examined the in vitro relationship between exogenous supplementation with DHA and breast cancer chemosensitivity to taxanes. We measured cell viability in the highly metastatic human breast cancer cell line MDA-MB-231 exposed sequentially to DHA followed by paclitaxel (Taxol) or docetaxel (Taxotere). As DHA by itself showed cytotoxic effects, possible synergistic interactions between DHA and taxanes were assessed, employing the combination index (CI) method and the isobologram analysis. Both methods showed a strong synergism (CI approximately 0.5; P<0.005) between DHA and taxanes in MDA-MB-231 cells. When the increase in taxanes efficacy was measured by dividing the IC50 values (50% inhibitory concentrations) obtained when the cells were exposed to taxanes alone by those after DHA pre-exposure, we found that DHA enhanced the cytotoxic activity of taxanes against MDA-MB-231 cells in a dose-dependent manner (up to 13- and 5-fold increase in Taxol and Taxotere efficacy, respectively). Importantly, sequential exposure to DHA followed by taxanes also yielded strong synergism in Her-2/neu (c-erbB-2)-overexpressing and taxanes-resistant SK-Br3 and BT-474 breast cancer cells. Moreover, exogenous supplementation with DHA significantly decreased the expression of Her-2/neu-codified p185(Her-2/neu) oncoprotein (up to 78% reduction in BT-474 cells). Our results provide experimental support to the hypothesis that omega-3 PUFAs can be used as modulators of tumor cell chemosensitivity and provide the rationale for in vivo preclinical investigation. In addition, this is the first study demonstrating that omega-3 PUFA DHA downregulates Her-2/neu oncogene expression in human breast cancer cells.

Monoclonal antibody to HER-2/neu receptor enhances radiosensitivity of esophageal cancer cell lines expressing HER-2/neu oncoprotein

The role of HER-2/neu in the response of esophageal cancer to radiation is not well known. The purpose of this study was to evaluate the effect of an anti-HER-2/neu antibody trastuzumab on the proliferation, cell cycle distribution, and radiosensitivity of esophageal cancer cell lines. Expression of HER-2/neu protein by four esophageal squamous cancer cell lines (KE4, TE8, TE9, and TE10) and an esophageal adenocarcinoma cell line (SKGT4) was assessed using immunohistochemical (IHC) analysis and flow cytometry. We also evaluated HER-2/neu oncogene expression by fluorescence in situ hybridization. As a control for HER-2/neu protein expression and gene amplification, breast cancer cell lines (MCF7, MDA MB175VII, and SKBR3) were also examined. The cytotoxity of trastuzumab (0.1-200 microg/mL) was estimated by the MTT assay, and the cell cycle distribution was determined by flow cytometry. The effect of 10 microg/mL trastuzumab combined with radiation was assessed by a clonogenic assay. Flow cytometry and IHC revealed that two esophageal cancer cell lines (TE9 and SKGT4) showed HER-2/neu expression (IHC 1+ and mean fluorescence intensity of 11-20), while the other esophageal cancer cell lines were negative for HER-2/neu expression. Although trastuzumab alone had no effect on the esophageal cancer cell lines, the combination of 10 microg/mL trastuzumab with radiation showed a synergistic effect on the HER-2/neu expressing cell lines. This study suggested that trastuzumab plus irradiation may be effective for the treatment of esophageal cancers, including adenocarcinoma and squamous cell cancer with HER-2/neu expression.

Pharmacological inhibition of fatty acid synthase (FAS): a novel therapeutic approach for breast cancer chemoprevention through its ability to suppress Her-2/neu (erbB-2) oncogene-induced malignant transformation.

We designed our experiments to evaluate whether fatty acid synthase (FAS), a lipogenic enzyme linked to tumor virulence in population studies of human cancer, is necessary for the malignant transformation induced by Her-2/neu (erbB-2) oncogene, which is overexpressed not only in invasive breast cancer but also in premalignant atypical duct proliferations and in ductal carcinoma in situ of the breast. To avoid the genetic complexities associated with established breast cancer cell lines, we employed NIH-3T3 mouse fibroblasts engineered to overexpress human Her-2/neu coding sequence. NIH-3T3/Her-2 cells demonstrated a significant upregulation of FAS protein expression, which was dependent on the upstream activation of mitogen-activated protein kinase and phosphatidylinositol 3'-kinase/AKT pathways. Remarkably, pharmacological FAS blockade using the mycotoxin cerulenin or the novel small compound C75 completely suppressed the state of Her-2/neu-induced malignant transformation by inhibiting the ability of NIH-3T3/Her-2 cells to grow under either anchorage-independent (i.e., to form colonies in soft agar) or low-serum monolayer conditions. Moreover, NIH-3T3/Her-2 fibroblasts were up to three times more sensitive to chemical FAS inhibitors relative to untransformed controls as determined by MTT-based cell viability assays. In addition, pharmacological FAS blockade preferentially induced apoptotic cell death of NIH-3T3/Her-2 fibroblasts, as determined by an ELISA for histone-associated DNA fragments and by the terminal deoxynucleotidyltransferase (TdT)-mediated nick end labeling assay (TUNEL). Interestingly, the degree of Her-2/neu oncogene expression in a panel of breast cancer cell lines was predictive of sensitivity to chemical FAS inhibitors-induced cytotoxicity, while low-FAS expressing and chemical FAS inhibitors-resistant MDA-MB-231 breast cancer cells became hypersensitive to FAS blockade when they were engineered to overexpress Her-2/neu. Our observations strongly suggest that inhibition of FAS activity may provide a new molecular avenue for chemotherapeutic prevention and/or treatment of Her-2/neu-related breast carcinomas.

Overexpression of Her-2/NEU in epithelial ovarian carcinoma induces vascular endothelial growth factor C by activating NF-kappa B: implications for malignant ascites formation and tumor lymphangiogenesis.

Vascular endothelial growth factor C (VEGF-C) is an important growth factor that governs lymphatic spread and the development of intraperitoneal tumors associated with epithelial ovarian cancer; however, its regulation is not yet understood. Overexpression of Her-2/NEU is related to poor survival in advanced epithelial ovarian carcinoma patients. Accordingly, this study attempted to analyze the association between the Her-2/NEU oncogene and VEGF-C in ovarian carcinoma and to elucidate the molecular mechanism of VEGF-C induction by Her-2/NEU. Immunohistochemistry was used to determine the expression of Her-2/NEU and VEGF-C in tissues from 41 patients with epithelial ovarian carcinoma. Several Her-2/NEU-stably-transfected Caov-3 ovarian carcinoma cells were used to evaluate the effect of Her-2/NEU on VEGF-C, the possible regulation mechanism, and the biological function of VEGF-C. Our experimental results identified a significant association between the Her-2/NEU oncogene and VEGF-C expression in both epithelial ovarian cancer patients (p < 0.05; Fisher's exact test) and in vitro cell lines. The overexpression of Her-2/NEU in Caov-3 ovarian cancer cells resulted in induction of a considerable amount of VEGF-C mRNA and protein; this process was dose-dependently inhibited by herceptin. The generation of VEGF-C significantly increased endothelial permeability. Pharmacological and genetic inhibition assays revealed that the cytoplasmic signaling molecule, p38 MAPK, and the transcriptional factor, NF-kappa B, are critically involved in the transcriptional activation of the VEGF-C gene by Her-2/NEU. In conclusion, this work clearly establishes that the Her-2/NEU oncogene is essential for the regulation of VEGF-C in ovarian carcinoma. It may be possible to use the monoclonal antibody targeting Her-2/NEU receptor to limit the formation of malignant ascites and lymphatic spread in ovarian carcinoma.

HER-2/neu oncogene expression in exfoliated human colonocytes from normal human subjects and colon cancer patients

HER-2/neu oncogene expression in exfoliated human colonocytes from normal human subjects and colon cancer patients

The Epstein–Barr virus nuclear antigen-1 may act as a transforming suppressor of the HER2/ neu oncogene

It is known that the HER2/ neu proto-oncogene is associated with a wide variety of human cancers and considered to be an attractive target for developing anti-cancer agents. We report here for the first time that the Epstein–Barr virus nuclear antigen-1 (EBNA1) suppresses the HER2/ neu oncogene expression at the transcriptional level. Recombinant clones of EBNA1 were subcloned and stably transfected into HER2/ neu-overexpressing human ovarian cancer SKOV3.ip1 cells. These EBNA1-containing clones down-regulated the endogenous production of p185 HER2/ neu . In addition, the EBNA1-expressing stable transfectants showed reduced growth rate, low soft agarose colony-forming ability and tumorigenic potential as compared with the parental line. These data suggest that EBNA1 may act as a transforming suppressor of the HER2/ neu oncogene.

The N-terminal 178-amino-acid domain only of the SV40 large T antigen acts as a transforming suppressor of the HER-2/neu oncogene.

The deregulation of the HER-2/neu protooncogene was demonstrated in a wide variety of human cancers and shown to be correlated with the progress of malignancy and metastasis in animal models. Repression of HER-2/neu overexpression suppressed the malignant phenotypes of HER-2/neu-overexpressing cancer cells. This suggested that HER-2/neu may be a good target for developing anti-cancer drugs. We found a deletion mutant of simian virus 40 (SV40) large T antigen (LT) suppresses the HER-2/neu oncogene expression at the transcriptional level. PCR clones of this mutant SV40LT, named LT425, which contains the N-terminal region of amino acid residues 1-178 of SV40LT, were subcloned and stably transfected into the HER-2/neu-overexpressing human ovarian cancer SKOV3.ip1 cells. These LT425 clones were found to be able to down-regulate the endogenous production of p185(HER-2/neu). In addition, the LT425-expressing stable transfectants showed reduced growth rate, low soft agarose colony forming ability, and low tumorigenic potential as compared with the parental line. These data suggested that the N-terminal 178 amino acids domain only of SV40LT may act as a transforming repressor of HER-2/neu oncogene.

Evaluation of HER-2/NEU (C-ERBB-2) Oncogene Expression in Whole Organ Sections of Supraglottic Squamous Cell Carcinoma

Adequate pathologic material and careful clinical follow-up are prerequisites for the analysis of the expression of particular oncogenic proteins that are prognostically important in squamous cell carcinoma of the larynx. The Gabriel Tucker, Jr, Collection of 150 whole organ specimens allows for the potential immunohistochemical study of the entire tumor. Sections from 32 supraglottic carcinomas were studied immunohistochemically for the presence of HER-2/neu (c-erbB-2) oncogene expression. Long-term follow-up data were available in all cases to assist in determining the prognostic significance of the specified oncogene in supraglottic squamous cell carcinoma. Our study revealed that joint presentation of immune staining for c-erbB-2 and positive lymph node status was significantly associated with distant metastasis (p=.00760).

C-erbB-2/neu Oncogene and Ki-67 analysis in the assessment of palatal salivary gland neoplasms

To evaluate the role of the Ki-67 proliferation antigen and c-erbB-2/neu oncogene expression in the clinical assessment of salivary gland tumors, we followed up 71 patients with minor salivary tumors of the palate. All benign neoplasms ( n = 18) showed low Ki-67 scores (<12%), whereas 26% (14 of 53) of malignant neoplasms manifested high Ki-67 scores (>12%). A significant statistical difference between Ki-67 scores for benign and malignant neoplasms was observed ( p <0.001). Ki-67 index also correlated significantly with malignant tumor grade ( p = 0.04) and patient survival ( p = 0.02). Only 1 of the 18 benign tumors had c-erbB-2/neu oncogene overexpression. A significant difference between c-erbB-2/neu overexpression in benign and malignant tumors was observed ( p = 0.01). Overexpression of c-erbB-2/neu oncogene was noted in 38% (16 of 42) of malignant tumors and was significantly associated with aggressive tumor behavior ( p <0.001). Multivariate analysis of significant factors revealed that gender, tumor stage, and c-erbB-2/neu oncogene overexpression were jointly predictive of survival. Our data indicate that although the Ki-67 proliferating antigen and c-erbB-2/neu oncogene expression may reflect certain intrinsic biologic properties of these neoplasms, only c-erbB-2/neu overexpression is significantly associated with their biologic aggression.(OTOLARYNGOL HEAD NECK SURG 1995;112:391-8.)

C‐erbB‐2/neu Oncogene and Ki‐67 Analysis in the assessment of palatal salivary gland neoplasms

To evaluate the role of the Ki-67 proliferation antigen and c-erbB-2/neu oncogene expression in the clinical assessment of salivary gland tumors, we followed up 71 patients with minor salivary tumors of the palate. All benign neoplasms (n = 18) showed low Ki-67 scores (< 12%), whereas 26% (14 of 53) of malignant neoplasms manifested high Ki-67 scores (> 12%). A significant statistical difference between Ki-67 scores for benign and malignant neoplasms was observed (p < 0.001). Ki-67 index also correlated significantly with malignant tumor grade (p = 0.04) and patient survival (p = 0.02). Only 1 of the 18 benign tumors had c-erbB-2/neu oncogene overexpression. A significant difference between c-erbB-2/neu overexpression in benign and malignant tumors was observed (p = 0.01). Overexpression of c-erbB-2/neu oncogene was noted in 38% (16 of 42) of malignant tumors and was significantly associated with aggressive tumor behavior (p < 0.001). Multivariate analysis of significant factors revealed that gender, tumor stage, and c-erbB-2/neu oncogene overexpression were jointly predictive of survival. Our data indicate that although the Ki-67 proliferating antigen and c-erbB-2/neu oncogene expression may reflect certain intrinsic biologic properties of these neoplasms, only c-erbB-2/neu overexpression is significantly associated with their biologic aggression.

Contribution of HER‐2/neu oncogene expression to tumor grade and DNA content analysis in the prediction of prostatic carcinoma metastasis

Recent advances in the early detection of prostatic adenocarcinoma have stimulated interest in the development of techniques for determining metastatic potential. One hundred cases of adenocarcinoma, including 66 biopsy and radical prostatectomy specimens; 20 biopsies alone; and 14 transurethral resection specimens, were evaluated for Gleason tumor grade, DNA content and HER-2/neu expression. DNA content was determined on Feulgen-stained touch preparations and tissue sections (18 cases) or tissue sections alone. HER-2/neu expression level was determined by image-analysis-assisted quantitative immunocytochemistry. Tumor grade and ploidy status were independent significant predictors of metastasis. HER-2/neu overexpression was found in 16 (16%) of the 100 cases and significantly correlated with high-tumor grade and aneuploid status, but was not of independent value in the prediction of metastasis. HER-2/neu overexpression is not uncommon in prostatic adenocarcinoma and is associated with high-tumor grade, abnormal DNA content, and distant metastasis. Tumor grade and DNA ploidy values are of the greatest value in determining the presence of metastasis.