Analysis of antigen expression at multiple tumor sites in epithelial ovarian cancer

Histopathological markers of treatment response and recurrence risk in ovarian cancers and borderline tumors

Histopathology plays an important role in defining response to treatment for different tumor types. Histopathologic response criteria are currently used as reference standard in various types of cancer, including breast cancer, gastroesophageal cancer, and bone tumors. Since there were no generally accepted response criteria established for ovarian cancer, a systematic analysis of various features of tumor regression was performed. Patient survival served as the reference standard to validate the histopathologic features of tumor regression. In contrast to ovarian cancer, borderline ovarian tumors are epithelial ovarian neoplasms characterized by up-regulated cellular proliferation and cytologic atypia but without destructive stromal invasion. While borderline ovarian tumors generally have an excellent prognosis with a 5‑year survival of > 95%, recurrences and malignant transformation occur in a small percentage of patients. Nevertheless, the identification of patients at increased risk for recurrence remains difficult. The aim of studying histopathological markers in ovarian cancers and borderline tumors was to evaluate whether histopathologic features including molecular pathologic alterations can predict patient outcome, particularly the risk of recurrence of serous and mucinous borderline tumors.

Relation between Ovarian Carcinoma-Associated Antigens in Tumor Tissue and Detached Cyst Fluid Cells of Patients with Ovarian Neoplasms

Aims

The expression and potential diagnostic value of ovarian carcinoma-associated antigens were estimated in different types of epithelial ovarian neoplasms. The comparison of antigenic expression was performed on solid tumor tissues and loose cyst fluid cells in individual cases of malignant and benign ovarian neoplasms.

Methods

All studies were performed using monoclonal antibodies (mAbs) against ovarian carcinoma-associated antigens (OC125, OV-TL3, OV632, 10B, 8C) by 3-step peroxidase-antiperoxidase test.

Results

All ovarian carcinoma-associated antigens were detected in most serous and endometrioid carcinomas. In mucinous carcinomas as well as in benign ovarian neoplasms these antigens were present only in some cases. Significant inter- and intratumoral immunological heterogeneity was evident; however, the antigens detectable in tissue sections were also found in detached cyst fluid cells.

Conclusions

Our results show that mAb show OV-TL3 is the best marker for endometrioid carcinomas and confirmed that mAbs OV632, OC125 and OV-TL3 could be good complementary markers for differentiating malignant and benign lesions in the ovary. The percentage content of all ovarian carcinoma-associated antigens in solid tumors and respective cyst fluid cells was comparable.

Cytomorphologic Characterization of Cell Subsets Isolated by Density Gradient Centrifugation from Tumor Effusions of Ovarian Endometrioid Carcinoma

Aims

Cytomorphologic characterization of tumor cell subsets, according to the stage of pathologic differentiation, and comparison of cellular composition in tumor cyst and ascitic fluids were carried out on individual patients with ovarian endometrioid carcinoma.

Methods

A density gradient centrifugation technique was applied to fractionate the cells from tumor effusions.

Results

The enrichment of cell forms representing individual stages of pathologic differentiation by gradient centrifugation facilitated their cytomorphologic characterization. According to cytomorphologic features, 5 discrete cell subpopulations were identified and catalogued. The cellular composition of tumor cyst and ascitic fluids in individual patients was similar, but the number of fractions and percentage of cell subsets differed.

Conclusions

The estimation of precise cytomorphologic criteria for cell forms in tumor effusions facilitated the cytologic diagnosis of ovarian endometrioid carcinoma. The possibility to concentrate poorly differentiated, frankly malignant cell subsets in low densities could significantly improve the diagnosis of tumor effusions.

AB0 blood groups and rhesus factor expression as prognostic parameters in patients with epithelial ovarian cancer - a retrospective multi-centre study

BACKGROUND

AB0 blood groups and Rhesus factor expression have been associated with carcinogenesis, response to treatment and tumor progression in several malignancies. The aim of the present study was to test the hypothesis that AB0 blood groups and Rhesus factor expression are associated with clinical outcome in patients with epithelial ovarian cancer (EOC).

METHODS

AB0 blood groups and Rhesus factor expression were evaluated in a retrospective multicenter study including 518 patients with EOC. Their association with patients' survival was assessed using univariate and multivariable analyses.

RESULTS

Neither AB0 blood groups nor Rhesus factor expression were associated with clinico-pathological parameters, recurrence-free, cancer-specific, or overall survival. In a subgroup of patients with high-grade serous adenocarcinoma, however, blood groups B and AB were associated with a better 5-year cancer-specific survival rate compared to blood groups A and 0 (60.3 ± 8.6% vs. 43.8 ± 3.6%, p = 0.04). Yet, this was not significant in multivariable analysis.

CONCLUSIONS

AB0 blood groups and Rhesus factor expression are both neither associated with features of biologically aggressive disease nor clinical outcome in patients with EOC. Further investigation of the role of the blood group B antigen on cancer-specific survival in the subgroup of high-grade serous should be considered.

Variation in cell signaling protein expression may introduce sampling bias in primary epithelial ovarian cancer

Although the expression of cell signaling proteins is used as prognostic and predictive biomarker, variability of protein levels within tumors is not well studied. We assessed intratumoral heterogeneity of protein expression within primary ovarian cancer. Full-length proteins were extracted from 88 formalin-fixed and paraffin-embedded tissue samples of 13 primary high-grade serous ovarian carcinomas with 5–9 samples each. In addition, 14 samples of normal fallopian tube epithelium served as reference. Quantitative reverse phase protein arrays were used to analyze the expression of 36 cell signaling proteins including HER2, EGFR, PI3K/Akt, and angiogenic pathways as well as 15 activated (phosphorylated) proteins. We found considerable intratumoral heterogeneity in the expression of proteins with a mean coefficient of variation of 25% (range 17–53%). The extent of intratumoral heterogeneity differed between proteins (p<0.005). Interestingly, there were no significant differences in the extent of heterogeneity between phosphorylated and non-phosphorylated proteins. In comparison, we assessed the variation of protein levels amongst tumors from different patients, which revealed a similar mean coefficient of variation of 21% (range 12–48%). Based on hierarchical clustering, samples from the same patient clustered more closely together compared to samples from different patients. However, a clear separation of tumor versus normal tissue by clustering was only achieved when mean expression values of all individual samples per tumor were analyzed. While differential expression of some proteins was detected independently of the sampling method used, the majority of proteins only demonstrated differential expression when mean expression values of multiple samples per tumor were analyzed. Our data indicate that assessment of established and novel cell signaling proteins as diagnostic or prognostic markers may require sampling of serous ovarian cancers at several distinct locations to avoid sampling bias.

Tubal and ovarian pathways to pelvic epithelial cancer: a pathological perspective

Prolongation of ovarian epithelial cancer survival depends on early detection or improved responses to chemotherapy. Gains in either have been modest at best. Understanding the diverse pathogenesis of this disease is critical to early intervention or prevention. This review addresses six important variables, including (i) cell of origin, (ii) site of origin, (iii) initial genotoxic events, (iv) risks imposed by hereditary and other promoting conditions, (v) subsequent factors that promote different patterns of metastatic spread, and (vi) prospects for intervention. This review proposes two distinct pathways to pelvic epithelial cancer. The first initiates in ovarian surface epithelium (OSE), Mullerian inclusions or endometriosis in the ovary. The second arises from the endosalpinx and encompasses a subset of serous carcinomas. The serous carcinogenic sequence in the distal fallopian tube is described and contrasted with lower grade serous tumors based on tumour location, earliest genetic change and ability (or lack of) to undergo terminal (ciliated) differentiation. Ultimately, a clear understanding of tumour origin and the mechanism(s) leading to the earliest phases of the serous and endometrioid carcinogenic sequences may hold the greatest promise for designing prevention strategies and/or developing new therapies.

Malignant effusions: From diagnosis to biology

Serous effusions are a frequently encountered clinical manifestation of metastatic disease, with breast, ovarian, and lung carcinomas and malignant mesothelioma (MM) leading the list. Recently, extensive research has resulted in expansion of the antibody panel that is available for effusion diagnosis, thereby reducing the risk for error. Despite this progress, relatively little has been done in way of understanding the biology of cancer cells in effusions, especially those of nonovarian origin. The diagnosis of a malignant effusion signifies disease progression and is associated with a worse prognosis regardless of the tumor site of origin. However, survival is much more variable with ovarian cancer compared with other tumors. Furthermore, cancer cells of different origins differ considerably in their biology and have unique phenotypic and genotypic characteristics. This review summarizes the current knowledge in this field and presents a model for the study of tumor metastasis and disease progression, through large comparative studies of malignant cells in effusions, primary tumors, and solid metastases. The case also is made for potential applications of this rapidly evolving body of knowledge in the diagnosis, classification, and prediction of biological behavior of processes resulting in cryptic effusions at the clinical level.

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

Ovarian carcinoma has a high mortality rate, because most ovarian carcinomas are detected at a late stage. Traditional therapies, such as surgical debulking and chemotherapy, have not been successful in improving the long-term survival of these patients. Alternative therapies targeting various biomarkers, such as carcinoembryonic antigen (CEA), Tag-72, and Lewis-Y antigen, have been developed to treat patients with advanced ovarian cancers. To ensure that therapies targeting these biomarkers are effective, it is imperative to determine whether there is any differential expression of these targeted biomarkers between primary and metastatic ovarian carcinomas. In the present study, primary and metastatic lesions from 68 and 58 patients, respectively, including primary and matched metastatic lesions from 31 patients, were evaluated for cytoplasmic and membranous expression of CEA (clone Col-1), Tag-72 (clone CC-49), and Lewis-Y antigen (clone BR-96) by immunohistochemistry. No significant differences were observed with cytoplasmic and membranous expression of Tag-72 (CC-49) and Lewis-Y antigen (BR-96) in the primary and metastatic, matched and unmatched lesions (Wilcoxon signed-rank test). Although there was no statistically significant difference in the scores of CEA (Col-1) between primary and metastatic lesions, 5 of 11 (45%) cases with positive staining with CEA (Col-1) demonstrated discordant results between primary and metastatic lesions. There was a moderate positive correlation of the cytoplasmic and membranous expression of Tag-72 (CC-49), as well as cytoplasmic expression of BR-96 between primary and metastatic ovarian carcinomas. There was a weak negative correlation between the membranous expression of CEA (Col-1) and that of Lewis-Y antigen (BR-96); however, the difference was not statistically significant. No correlation was observed with other combinations of biomarkers. Our findings suggest that samples from either primary or metastatic ovarian carcinomas can be used for the evaluation of the expression of Tag-72 (CC-49) and Lewis-Y antigen (BR-96) to identify targets for novel therapies in patients with disseminated ovarian carcinomas. CEA (Col-1), due to its low expression and variation in phenotypic expression between primary and metastatic lesions, should be evaluated carefully in metastatic lesions before targeting the CEA antigen with CEA (Col-1)-like antibodies.

Effusion cytology in ovarian cancer: new molecular methods as aids to diagnosis and prognosis

Carcinoma of the ovary is the leading cause of death from gynecologic cancer in western countries. Ovarian carcinoma is commonly associated with the accumulation of fluid that contains malignant cells in the peritoneal and pleural cavities. This article details the current knowledge regarding the diagnostic and biologic characteristics of ovarian carcinoma cells in effusions, and the genotypic and phenotypic differences between solid primary tumors and metastatic lesions. Finally, we present a new approach, by which the analysis of fresh frozen viable cells allows us to study in vivo the links between expression and activity of extracellular mediators, membrane receptors, intracellular signaling, and transcription factors, and their potential therapeutic and prognostic significance.

Expression of carbohydrate antigens in advanced-stage ovarian carcinomas and their metastases-A clinicopathologic study

OBJECTIVE

Up-regulated expression or loss of expression of various carbohydrate antigens on the surface of cancer cells has been associated with a metastatic phenotype and poor survival in epithelial malignancies of different origins. The object of this study was to investigate the expression of carbohydrate antigens in two groups of patients diagnosed with advanced-stage ovarian carcinoma-one with an extremely favorable outcome and the other with a uniformly poor survival.

METHODS

Sections from 76 paraffin-embedded blocks (primary ovarian carcinomas and metastatic lesions) from 45 patients diagnosed with advanced-stage ovarian carcinomas (FIGO stages III-IV) were immunohistochemically stained using five monoclonal antibodies for Lewis(y) (Le(y))(two antibodies), Sialyl Lewis(x) (Slex), Tn, and Sialyl Tn (STn) antigens. Patients were divided in two groups based on outcome. Long-term survivors (21 patients) and short-term survivors (24 patients) were defined using a double cut-off of 36 months for disease-free survival (DFS) and 60 months for overall survival (OS). Staining results for primary tumors and metastases were analyzed separately.

RESULTS

Mean follow-up period was 70 months. The mean values for DFS and OS were 109 and 125 months for long-term survivors and 3 and 25 months for short-term survivors. Staining for all four antigens was seen in the majority of cases (range = 72-96%) and tended to be comparable in primary tumors and their metastases. However, absence of immunoreactivity for STn was seen in 9/38 (24%) metastatic lesions and only 1/38 (3%) primary tumors. This finding did not reach statistical significance (P > 0.05). A combined pattern of membranous and cytoplasmic staining was predominant in the majority of cases. Enhanced staining for Le(y) and STn was detected in the invasive front of some tumors, while Slex and Tn immunoreactivity did not relate to cell location. Primary tumors and metastatic lesions of long-term survivors displayed immunoreactivity patterns that were comparable to those of short-term survivors. In the evaluation of survival curves, more diffuse staining for Slex showed marginal correlation with poor survival (P = 0.05), while a trend toward poorer survival was seen in tumors that were more extensively stained for Le(y) and Tn (P > 0.05).

CONCLUSIONS

Le(y), Slex, STn, and Tn antigens are widely expressed in primary ovarian carcinomas and their metastases. Altered expression of Sialyl Tn is observed with tumor progression in a fraction of ovarian carcinomas. Expression of membrane carbohydrate residues is prevalent in tumors of both long-term and short-term survivors and does not appear to be a strong predictor of disease outcome. However, larger studies are needed to further elucidate the role of these molecules in ovarian carcinogenesis.

Selection of carbohydrate antigens in human epithelial ovarian cancers as targets for immunotherapy: serous and mucinous tumors exhibit distinctive patterns of expression

Expression of blood group-related carbohydrate antigens was examined in frozen sections from a series of ovarian carcinomas of different histological types using an indirect immunoperoxidase technique. Antigenic specificities belonging to the O(H) and Lewis blood group families (H-1, H-2, Le(a), sLe(a), Le(x), sLe(x), Le(b) and Le(y)) or the mucin-core family (Tn, sTn and TF) were studied. A distinct difference in antigen expression between mucinous and other ovarian carcinomas (serous and endometrioid) was observed. Specifically, mucinous tumors tended to express sTn, Le(a) and sLe(a) strongly and homogeneously, whereas serous and endometrioid tumors rarely expressed these specificities and, in contrast, expressed Le(y) and H type 2 antigen strongly. When expressed in serous tumors, sTn was usually distributed in a heterogeneous pattern, whereas sTn expression in mucinous tumors was much more homogeneous. The distribution of Le(y) in serous tumors was noticeably homogeneous. H-1, Le(x), sLe(x), Le(b), TF and Tn specificities were rarely expressed in any type of ovarian carcinoma. Our results provide further support for the different histogenesis of mucinous and non-mucinous tumors and indicate alternative differentiation pathways for the 3 pathological subtypes of ovarian tumor. They also provide the basis for the choice of carbohydrate antigens for active and passive immunotherapy of ovarian carcinomas.

Recent developments in radioimmunotherapy

With the advent of monoclonal antibody techniques, there has been renewed interest in RIT as a treatment modality in patients with a variety of tumour types. There has been a considerable research effort to increase understanding of the scientific basis of such therapy at all levels. Antibody, chelator and radioisotope factors are all the subject of research aimed at producing a potent effector system capable of maximal target cell kill with acceptable normal tissue toxicity. Improved knowledge of the host and tumour factors which limit access to the target cell offers the possibility of optimizing targeting and increasing the therapeutic index. Target cell factors that influence response to low dose rate RIT have been elucidated and provide an opportunity to integrate the treatment modality into radical therapy regimens. A number of Phase I and II trials have now been performed in various tumour types. The results have been promising but, as yet, the prospect of radical RIT remains a research goal. Before it can be achieved it will be necessary to improve specific tumour cell targeting and to increase both the initial dose rates and the total dose delivered to tumour deposits. Until such time, it is likely that RIT will be incorporated into multimodality protocols to deliver a moderate (10-20 Gy) tumour boost, or in an adjuvant setting in patients with minimal residual disease.

Monoclonal antibodies in the management of ovarian cancer. A clinical perspective

Despite recent advances in the conventional management of ovarian cancer, this disease remains the leading cause of death among the gynecologic malignancies, killing more American women each year than all other gynecologic cancers combined. As a tumor arising from a nonessential organ that remains primarily confined to the peritoneal cavity, ovarian cancer makes an attractive target for monoclonal antibodies (MoAb). Several MoAb have been developed that have actual or potential clinical use in the management of ovarian cancer. Serum assays using a MoAb against an ovarian cancer-associated antigen (CA 125) are currently in routine clinical use for monitoring the course of disease in women with known ovarian cancer. Such assays may play a role in multitechnique screening programs. Radiolabeled antibodies are under study for use in external imaging or intraoperative detection of ovarian cancer. Isotope-labeled antibodies also are being evaluated in the treatment of ovarian cancer as are antibodies coupled to drugs or biologic toxins. Some antibodies may have direct antitumor effects through binding to biologically active receptors or through immune effector functions. The use of antibody fragments, chimeric antibodies, human antibodies, and genetically engineered antibodies is under active investigation. MoAb have important potential for improving the diagnosis, monitoring of response to therapy, and treatment of ovarian cancer.