Expression of CEA, Tag-72, and Lewis-Y antigen in primary and metastatic lesions of ovarian carcinoma

Blood group-related antigen Ley on human platelets and its involvement in platelet aggregation via a possible interaction with CD61

BACKGROUND

The Le^y antigen is a carbohydrate chain belonging to the ABH-Lewis blood group family. Le^y has been reported to be present on red blood cells (RBCs) and granulocytes, but its distribution and function in platelets remain unknown. There are a variety of glycoproteins on platelets, which may carry the Le^y antigen. This study aims to investigate the expression pattern and the function of Le^y in human platelets.

STUDY DESIGN AND METHODS

Flow cytometry, Western blot, and immunofluorescence assays were performed to determine Le^y expression on human platelets. ADP (1.25-10 μM) and thrombin (0.05-1 IU/mL) were used to activate platelets in the presence or absence of prostaglandin E1 (PGE1) and the Le^y expression was evaluated again by flow cytometry. Blockade was performed with an anti-Le^y monoclonal antibody to verify the role of this epitope in platelet function. Finally, coimmunoprecipitation was performed to identify glycoproteins associated with Le^y .

RESULTS

Le^y was expressed on human platelets independent of ABO blood type. Le^y expression was decreased in a dose-dependent manner after activation with either ADP or thrombin, and this effect could be partially reversed by PGE1. Anti- Le^y mAb treatment increased alpha-granule release and neutralized the inhibitory effect of the anti-CD61 antibody on platelet aggregation. In addition, Le^y was proven to interact and colocalize with CD61.

CONCLUSIONS

These results demonstrate nondifferential expression of Le^y in platelets of different ABO blood types and suggest the involvement of Le^y in platelet function, possibly via interaction with CD61.

Lewis(y) antigen promotes the progression of epithelial ovarian cancer by stimulating MUC1 expression

MUC1 is a type I transmembrane glycoprotein and is overexpressed in various epithelial tumor tissues. Some researchers have demonstrated that the glycosylation status of MUC1 can affect MUC1-mediated tumor growth and cell differentiation. In our previous study, we proved that the abilities of cell proliferation, adhesion, invasion and metastasis, and drug resistance were enhanced in ovarian cancer cells stably expressing Lewis(y). Therefore, we hypothesized that Lewis(y) antigen may play a central role in regulating MUC1 expression, and MUC1-mediated cell growth and differentiation may be closely associated with Lewis(y) antigen. This study aimed to examine the correlation between MUC1 expression and Lewis(y) antigen levels in ovarian cancer cell lines and tissue samples. A series of techniques, including RT-qPCR, western blot anlaysis, immunoprecipitation, immunohistochemistry and double-labeling immunofluorescence were applied to detect the expression of Lewis(y) and MUC1. In malignant epithelial ovarian tumors, the positive expression rates of Lewis(y) antigen and MUC1 were 88.33 and 86.67%, respectively, which were markedly higher than those in borderline (60.00 and 53.33%, P<0.05), benign (33.33 and 30%, P<0.01) and normal (0 and 25%, P<0.01) ovarian samples. There was no correlation between the positive expression rates of Lewis(y) or MUC1 and clinicopathological parameters in ovarian cancers (P>0.05). The expression levels of Lewis(y) and MUC1 correlated with the clinical FIGO stage (P<0.05). Both MUC1 and Lewis(y) were highly expressed in ovarian cancer tissues, and their expression levels were positively correlated (P<0.01). In α1,2-fucosyltransferase (α1,2-FT)-transfected cells, the gene and protein expression levels of MUC1 were significantly upregulated compared with the cells that did not overexpress α1,2-FT (P<0.05). The ratio of Lewis(y) immunoprecipitated with MUC1 to total MUC1 increased 1.55-fold in α1,2-FT-overexpressing cells (P<0.05). The overexpression of Lewis(y) resulted in the upregulation of MUC1. On the whole, our data indicate that both MUC1 and Lewis(y) are associated with the occurrence and development of ovarian cancers.

Lewis y enhances CAM-DR in ovarian cancer cells by activating the FAK signaling pathway and upregulating Bcl-2/Bcl-XL expression

Oligosaccharides on the surface of adhesion molecules may contribute to the process of CAM-DR. To investigate the role of the Lewis y antigen in this process, we established a cell adhesion model mediated by the integrin α5β1-FN interaction in the ovarian cancer cell line, RMG-1-hFUT, which highly expresses Lewis y by transfection with α1,2-fucosyltransferase into RMG-1 cells. Our results indicate that the rates of carboplatin-induced apoptosis and necrosis are reduced in FN-adhered tumor cells, and carboplatin resistance is significantly decreased in the presence of anti-Lewis y antibody. CAM-DR in tumor cells has been correlated with elevated expression of the nuclear anti-apoptotic proteins Bcl-2 and Bcl-XL. Lewis y promotes the expression of the Bcl-2 and Bcl-XL genes by activating the focal adhesion kinase signaling pathway and accelerating their transcription. Thus, Lewis y leads to inhibition of apoptosis and enhancement of CAM-DR by activation of the FAK signaling pathway and upregulation of Bcl-2/Bcl-XL expression in ovarian cancer cell lines.

The expression of annexin II and Lewis y antigen in ovarian epithelial tumors and the correlation between them

The main aim of this study was to explore the molecular structural relationship between annexin II (ANXA2) and Lewis y antigen by determining their expression patterns and clinical significance in ovarian epithelial carcinoma. The structural relationship between ANXA2 and Lewis y antigen was examined using immunoprecipitation and confocal laser scanning microscopy in two ovarian caner cell lines ES-2 and CaoV-3. We also constracted the stably transfected cell lines with low ANXA2 gene expression in order to detect the expression level between ANXA2 and Lewis y. ANXA2 and Lewis y were detected in tissues from malignant, borderline, benign, and normal ovarian tissues using immunohistochemical analysis. ANXA2 and Lewis y were present in both two ovarian cancer cells and ANXA2 contained Lewis y antigen. Moreover, expression of Lewis y antigen in ANXA2 from cell after transfection was higher than that before. Our immunohistochemistry data revealed significantly higher positive expression rates of ANXA2 in malignant ovarian tissues, compared to benign tumor and normal tissue, similar to Lewis y antigen levels in ovarian cancer. Notably, tissues displaying marked expression of ANXA2 simultaneously expressed high levels of Lewis y antigen. A linear correlation between the expression patterns of ANXA2 and Lewis y antigen was evident. Consistently, double-labeling immunofluorescence experiments illustrated co-localization of ANXA2 and Lewis y antigen within the same area. In conclusions, ANXA2 contains Lewis y antigen. Our results further demonstrate a close correlation between the expression levels of the two antigens, which are significantly high in ovarian cancer.

Overexpression of Lewis y antigen promotes human epididymis protein 4-mediated invasion and metastasis of ovarian cancer cells

To study Human epididymis protein 4 (HE4) surface fucosylation and to determine the effects and significance of Lewis y antigen on HE4-mediated invasion and metastasis of ovarian cancer cells, we investigated four types of ovarian cancer cells and found that six fucosylated antigens (Lewis y, Lewis x, Lewis a, Lewis b, sLewis a, and sLewis x) were identified on HE4 in ovarian cancer cells. Moreover, modification of the type II sugar chain (Lewis y, Lewis x, and sLewis x) was significantly higher than the type I sugar chain (Lewis a, Lewis b, sLewis a) of the lactose series. To confirm the effects of Lewis y antigen on HE4-mediated invasion and metastasis of ovarian cancer cells, the CaoV-3 cells with high Lewis y antigen on the HE4 surface and ES-2 cells, with high Lewis x antigen but low Lewis y antigen, were investigated. We found that the expression levels of HE4 and Lewis y increased in both cell lines while the level of Lewis x didn't have any change after transfection. Furthermore, the high expression of Lewis y antigen significantly enhanced the HE4-mediated invasion and metastasis of ovarian cancer cells. The invasion and metastasis capacities were significantly decreased after Lewis y antibody blocking. This study demonstrates that overexpression of the Lewis y antigen on HE4 promotes ovarian cancer cell invasion and metastasis, which is likely to be used as a target for the clinical treatment of ovarian cancer.

Co-expression of Lewis y antigen with human epididymis protein 4 in ovarian epithelial carcinoma

Objective

The main aims of this study were to explore the molecular structural relationship between Human epididymis protein 4 (HE4) and Lewis y antigen by determining their expression patterns and clinical significance in ovarian epithelial carcinoma.

Methods

The structural relationship between HE4 and Lewis y antigen was examined using immunoprecipitation and confocal laser scanning microscopy. HE4 and Lewis y were detected in tissues from malignant (53 cases), borderline (27 cases), benign (15 cases) and normal ovarian tissues (15 cases) using immunohistochemical analysis.

Results

HE4 was present in ovarian cancer, benign tumor tissues, ovarian carcinoma cells, and culture medium, and contained Lewis y antigen. Moreover, expression of Lewis y antigen in HE4 from ovarian cancer was higher than that from benign tumor (P<0.05). HE4 possibly exists as two protein isoforms, both containing Lewis y antigen. Our immunohistochemistry data revealed significantly higher positive expression rates of HE4 in malignant ovarian tissues, compared to benign tumor and normal tissue (P<0.05), similar to Lewis y antigen levels in ovarian cancer (P<0.05). Notably, tissues displaying marked expression of HE4 simultaneously expressed high levels of Lewis y antigen. A linear correlation between the expression patterns of HE4 and Lewis y antigen was evident. Consistently, double-labeling immunofluorescence experiments illustrated co-localization of HE4 and Lewis y antigen within the same area.

Conclusions

HE4 contains Lewis y antigen. Our results further demonstrate a close correlation between the expression levels of the two antigens, which are significantly high in ovarian cancer.

Treatment of peritoneal carcinomatosis from breast cancer by maximal cytoreduction and HIPEC: a preliminary report on 5 cases

Although peritoneal carcinomatosis from breast cancer is a rare event it frequently causes morbidity and mortality. Current literature provides scarce information on its management. We report outcomes in 5 patients (mean age 59.4 years) with peritoneal carcinomatosis from breast cancer treated with maximal cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) by the closed technique, at 40 °C for 1 h with cisplatin 75 mg/m(2). The primary breast cancer was a ductal carcinoma in 3 patients and a lobular carcinoma in 2. Mean peritoneal cancer index was 20.2. In 4 of the 5 patients surgery achieved macroscopic complete cytoreduction. One patient died of disease at 56 months, 4 are alive and disease-free at 13, 45, 74 and 128 months. These encouraging outcomes suggest that cytoreduction and HIPEC is a promising approach to offer to highly selected patients with peritoneal carcinomatosis from breast cancer and that this approach merit investigation in a larger series.

Carbohydrate biomarker recognition using synthetic lectin mimics

Carbohydrate biomarkers play very important roles in a wide range of biological and pathological processes. Compounds that can specifically recognize a carbohydrate biomarker are useful for targeted delivery of imaging agents and for development of new diagnostics. Furthermore, such compounds could also be candidates for the development of therapeutic agents. A tremendous amount of active work on synthetic lectin mimics has been reported in recent years. Amongst all the synthetic lectins, boronic-acid-based lectins (boronolectins) have shown great promise. Along this line, four classes of boronolectins including peptide-, nucleic-acid-, polymer-, and small-molecule-based ones are discussed with a focus on the design principles and recent advances. We hope that by presenting the potentials of this field, this review will stimulate more research in this area.

Lewis Y regulates signaling molecules of the transforming growth factor β pathway in ovarian carcinoma-derived RMG-I cells

LeY (Lewis Y) is a difucosylated oligosaccharide carried by glycoconjugates on the cell surface. Elevation of LeY is frequently observed in epithelial-derived cancers and is correlated to pathological staging and prognosis. To study the role of LeY on cancer cells, a stably LeY-overexpressing cell line, RMG-I-H, was developed previously by transfection of the α1,2-fucosyltransferase gene, a key enzyme that catalyzes the synthesis of LeY, into ovarian carcinoma-derived RMG-I cells. Our studies have shown that LeY is involved in the changes in biological behavior of RMG-I-H cells. However, the mechanism is still largely unknown. In this study, we determined the structural relationship and co-localization between LeY and TβRI/TβRII, respectively, and the potential cellular signaling mechanism was also investigated. We found that both TβRI and TβRII contain the LeY structure, and the level of LeY in TβRI and TβRII in RMG-I-H cells was significantly increased. Overexpression of LeY up-regulates the phosphorylation of ERK, Akt and down-regulates the phosphorylation of Smad2/3. In addition, the phosphorylation intensity was attenuated significantly by LeY monoantibody. These findings suggest that LeY is involved in the changes in biological behavior through TGF-β receptors via Smad, ERK/MAPK and PI3K/Akt signaling pathways. We suggest that LeY may be an important composition of growth factor receptors and could be an attractive candidate for cancer diagnosis and treatment.

Increase in docetaxel-resistance of ovarian carcinoma-derived RMG-1 cells with enhanced expression of Lewis Y antigen

Epithelial carcinomas of the ovary exhibit the highest mortality rate among gynecologic malignancies. Studies found that the metabolism of glycolipids or carbohydrates is associated with acquirement of anticancer drug-resistance by cancer cells. This study was to characterize possible involvement of Lewis Y (Le(Y)) antigen in the drug-resistance of cancer cells. We transfected the α1,2-fucosyltransferase gene into human ovarian carcinoma-derived RMG-1 cells and established RMG-1-hFUT cells with enhanced expression of Le(Y). We determined the effects of docetaxel on the survival of cells by MTT assaying and observed the apoptosis of cells in the presence of docetaxel by flow cytometric analysis and by transmission electron microscopy. Plasma membranes and intracellular granules in RMG-1-hFUT cells were stained with anti-Le(Y) antibody, the intensity of the staining was higher than that in control cells. The RMG-1-hFUT cells exhibited higher resistance to docetaxel than the control cells with regard to the docetaxel concentration and time course. After treatment with 10 μg/mL docetaxel for 72 h, the control cells, but not RMG-1-hFUT, contained abundant positively stained cell debris due to disintegration of the cytoskeleton. On transmission electron microscopy, although the control cells treated with docetaxel as above showed the following morphology, i.e., absence of villi, cells shrunken in size, pyknosis, agglutinated chromatin and cell buds containing nuclei in the process of apoptosis, the RMG-1-hFUT cells showed only agglutinated chromatin and vacuoles in the cytoplasm. In summary, cells with enhanced expression of Le(Y) were shown to acquire docetaxel-resistance, indicating the possible involvement of glycoconjugates in the drug-resistance.

Phylogenetic discordance of human and canine carcinoembryonic antigen (CEA, CEACAM) families, but striking identity of the CEA receptors will impact comparative oncology studies

Comparative oncology aims at speeding up developments for both, human and companion animal cancer patients. Following this line, carcinoembryonic antigen (CEA, CEACAM5) could be a therapeutic target not only for human but also for canine (Canis lupus familiaris; dog) patients. CEACAM5 interacts with CEA-receptor (CEAR) in the cytoplasm of human cancer cells. Our aim was, therefore, to phylogenetically verify the antigenic relationship of CEACAM molecules and CEAR in human and canine cancer.

Anti-human CEACAM5 antibody Col-1, previously being applied for cancer diagnosis in dogs, immunohistochemically reacted to 23 out of 30 canine mammary cancer samples. In immunoblot analyses Col-1 specifically detected human CEACAM5 at 180 kDa in human colon cancer cells HT29, and the canine antigen at 60, 120, or 180 kDa in CF33 and CF41 mammary carcinoma cells as well as in spontaneous mammary tumors. While according to phylogenicity canine CEACAM1 molecules should be most closely related to human CEACAM5, Col-1 did not react with canine CEACAM1, -23, -24, -25, -28 or -30 transfected to canine TLM-1 cells. By flow cytometry the Col-1 target molecule was localized intracellularly in canine CF33 and CF41 cells, in contrast to membranous and cytoplasmic expression of human CEACAM5 in HT29. Col-1 incubation had neither effect on canine nor human cancer cell proliferation. Yet, Col-1 treatment decreased AKT-phosphorylation in canine CF33 cells possibly suggestive of anti-apoptotic function, whereas Col-1 increased AKT-phosphorylation in human HT29 cells. We report further a 99% amino acid similarity of human and canine CEA receptor (CEAR) within the phylogenetic tree. CEAR could be detected in four canine cancer cell lines by immunoblot and intracellularly in 10 out of 10 mammary cancer specimens from dog by immunohistochemistry. Whether the specific canine Col-1 target molecule may as functional analogue to human CEACAM5 act as ligand to canine CEAR, remains to be defined. This study demonstrates the limitations of comparative oncology due to the complex functional evolution of the different CEACAM molecules in humans versus dogs. In contrast, CEAR may be a comprehensive interspecies target for novel cancer therapeutics.

Lewis Y promotes growth and adhesion of ovarian carcinoma-derived RMG-I cells by upregulating growth factors

Lewis y (LeY) antigen is a difucosylated oligosaccharide carried by glycoconjugates on the cell surface. Overexpression of LeY is frequently observed in epithelial-derived cancers and has been correlated to the pathological staging and prognosis. However, the effects of LeY on ovarian cancer are not yet clear. Previously, we transfected the ovarian cancer cell line RMG-I with the α1,2-fucosyltransferase gene to obtain stable transfectants, RMG-I-H, that highly express LeY. In the present study, we examined the proliferation, tumorigenesis, adhesion and invasion of the cell lines with treatment of LeY monoclonal antibody (mAb). Additionally, we examined the expression of TGF-β1, VEGF and b-FGF in xenograft tumors. The results showed that the proliferation and adhesion in vitro were significantly inhibited by treatment of RMG-I-H cells with LeY mAb. When subcutaneously inoculated in nude mice, RMG-I-H cells produced large tumors, while mock-transfected cells RMG-I-C and the parental cells RMG-I produced small tumors. Moreover, the tumor formation by RMG-I-H cells was inhibited by preincubating the cells with LeY mAb. Notably, the expression of TGF-β1, VEGF and b-FGF all increased in RMG-I-H cells. In conclusion, LeY plays an important role in promoting cell proliferation, tumorigenecity and adhesion, and these effects may be related to increased levels of growth factors. The LeY antibody shows potential application in the treatment of LeY-positive tumors.

Carbohydrate recognition by boronolectins, small molecules, and lectins

Carbohydrates are known to mediate a large number of biological and pathological events. Small and macromolecules capable of carbohydrate recognition have great potentials as research tools, diagnostics, vectors for targeted delivery of therapeutic and imaging agents, and therapeutic agents. However, this potential is far from being realized. One key issue is the difficulty in the development of "binders" capable of specific recognition of carbohydrates of biological relevance. This review discusses systematically the general approaches that are available in developing carbohydrate sensors and "binders/receptors," and their applications. The focus is on discoveries during the last 5 years.

An HLA-DR-degenerate epitope pool detects insulin-like growth factor binding protein 2-specific immunity in patients with cancer

Recent studies have shown the importance of helper CD4 T cells in initiating and sustaining tumor-specific CD8 T-cell immunity. This has paved the way for identifying MHC class II epitopes that could be incorporated into class I-based vaccines. In this study, the goal was to identify an HLA-DR-degenerate epitope pool derived from insulin-like growth factor binding protein 2 (IGFBP-2). IGFBP-2, a regulator of insulin-like growth factor action, is overexpressed in the majority of breast and ovarian cancers. Using algorithms, we predicted 29 HLA-DR1-binding epitopes. Binding assays targeting 15 different HLA-DRs revealed that 10 epitopes were degenerate, binding to at least four different HLA-DR variants. An IFN-gamma enzyme-linked immunosorbent spot assay was used to assess immunity to these 10 epitopes in 48 patients with either breast or ovarian cancer and 18 controls. Elevated T-cell immunity in patients was detected in 4 of the 10 epitopes (IGFBP2.17, IGFBP2.22, IGFBP2.249, and IGFBP2.293). The cumulative T-cell frequency of these four epitopes was elevated in patients relative to controls. All four peptides are naturally processed and presented to CD4 T-cells. The degenerate pool of peptides covers nearly 80% of patients and may be useful for augmenting CD4 T-cell immunity in patients undergoing immunization.

Expression of TAG-72 in ovarian cancer and its correlation with tumor stage and patient prognosis

Tumor associated glycoprotein-72 (TAG-72), a pancarcinoma antigen, was initially identified in cancer tissues by its immunoreactivity to a monoclonal antibody B72.3. In this study, we have analyzed the expression and localization profiles of TAG-72 in ovarian cancer tissue samples of different stages and histological subtypes by immunohistochemistry using a second generation high affinity monoclonal antibody CC49. We have also studied the expression of TAG-72 in ovarian cancer cell lines by confocal microscopy and immunoblot analyses. A correlation between TAG-72 expression and localization with patients' prognosis was also analyzed using Kaplan-Meier analysis. Eighty eight percent of the ovarian cancer tissue samples (n=43) showed immunoreactivity with CC49 antibody. The expression of TAG-72 in advanced stage cancer tissues (mean composite score=3.7) was significantly higher (p=0.035) compared to the early stage tumors (mean composite score=2.3). However, no significant correlation of TAG-72 was observed with histological tumor types. A marginal correlation of TAG-72 staining with patients' survival was observed. Interestingly, the membrane localization of TAG-72 in tumors was significantly (p=0.0082) associated to the poor clinical outcome, while cytoplasmic staining was correlated significantly to a better prognosis (p=0.0051). Immunoblot analysis demonstrated the expression of TAG-72 in three ovarian cancer cell lines (OVCAR3, SB247 and COV362.4). In conclusion, the tumor-specific expression of TAG-72 and its association with disease stage indicate its potential as a marker for effective disease management and targeted cancer therapy.

Minimal residual disease in ovarian cancer as a target for complement-mediated mAb immunotherapy

Ovarian cancer is potentially well suited for local monoclonal antibody (mAb) immunotherapy, because it remains within the peritoneal cavity for a long period of time before giving rise to distant metastases. At the stage of minimal residual disease, the cells appear to be in a state of dormancy (G(0)) or at least have lower rates of tumour cell proliferation. They should be a promising target for immunotherapy. Here we first examined the cell-cycle expression of CD59 and decay-accelerating factor (DAF; CD55) on four different ovarian carcinoma cell lines, using simultaneous flow cytometric analysis of DNA content or the cell-cycle-specific nuclear proliferation protein Ki67 and CD59 or DAF surface expression. We found that CD59 and DAF are stably expressed throughout the cell cycle. The polyvalent approach to target-independent antigens to improve the efficiency of mAb complement (C)-mediated damages was promising, and tumour cells become sensitive to C damage, when incubated with cross-linked mAb against different tumour-associated antigens. Although, such immune complex-mediated C activation was rather ineffective in killing the cells, it could be potentiated by the addition of blocking mAb against CD59 and DAF. Our results suggest that the activities of intrinsic C regulators must be neutralized to make minimal residual disease a promising target for antibody therapy.

Expression of WT1, CA 125, and GCDFP-15 as Useful Markers in the Differential Diagnosis of Primary Ovarian Carcinomas Versus Metastatic Breast Cancer to the Ovary

Metastatic breast carcinoma to the ovary is sometimes difficult to differentiate from primary ovarian carcinoma. This problem is often encountered in breast carcinoma patients who develop adnexal masses. ER and PR can be positive in a high percentage of breast and ovarian carcinomas, and therefore cannot be used in the differential diagnosis of these entities. WT1 and CA125 have been identified as possible markers for ovarian cancer. However, no studies have been done that specifically compare the immunophenotype of breast carcinoma metastatic to ovary with that of primary ovarian cancer. Thirty-nine cases of metastatic breast carcinoma to the ovary, 36 primary breast carcinomas, and 42 primary ovarian carcinomas were examined immunohistochemically for the expression of WT1, CA125, carcinoembryonic antigen, MUC2, MUC1, and GCDFP. The percentage of cells stained and the intensity of staining were recorded. Thirty-two ovarian carcinomas (76%) were positive for WT1, including 31 of 33 (94%) serous carcinomas. Most of them had strong and diffuse staining. None of the breast cancers either primary or metastatic to the ovary expressed WT1. Thirty-eight (90%) ovarian carcinomas were positive for CA125, most of them with strong and diffuse staining. Most breast carcinomas were negative for CA125, with only 6 (16%) of the primary ones and 5 (12%) of the metastatic showing weak and focal positivity. All ovarian carcinomas were negative for GCDFP. Five primary breast cancers (14%) and 17 (43%) metastatic to the ovary were positive for GCDFP. Nine (21%) ovarian carcinomas, 8 (22%) primary breast carcinomas, and 13 (33%) metastatic to the ovary were positive for carcinoembryonic antigen. Almost all tumors examined were positive for MUC1 (100% ovarian carcinomas, 100% primary breast carcinomas, and 95% metastatic breast carcinomas to ovary). MUC2 was positive in 10 (24%) ovarian carcinomas, 3 (8%) primary breast cancers, and 12 (30%) metastases to the ovary. The presence of immunoreactivity for WT1 and CA125 in a carcinoma involving ovary strongly favors a primary lesion. Most ovarian carcinomas are positive for both markers, whereas the majority of metastatic breast carcinomas to the ovary are negative. GCDFP can be complementary in this differential diagnosis.