Immunophenotype of ovarian cancer as predictor of clinical outcome: evaluation at primary surgery and second-look procedure

HER2 Protein Overexpression and Gene Amplification in Tubo-Ovarian High-grade Serous Carcinomas

Most tubo-ovarian high-grade serous carcinomas (TO-HGSC) are diagnosed in advanced stages. Although the majority of patients achieve initial remission with cytoreductive surgery and chemotherapy, mortality rate remains high due to recurrent/progressive disease. The addition of trastuzumab to carboplatin-paclitaxel improved progression-free survival of patients with human epidermal growth factor receptor 2 (HER2)-positive uterine serous carcinoma. After this encouraging result of transtuzumab in HER2-positive uterine serous carcinoma, we aimed to determine the frequency of HER2 overexpression/amplification in TO-HGSC and reveal the utility of 2018 ASCO/CAP HER2 testing guideline in breast cancer for TO-HGSC. For 100 cases, HER2 protein expression was assessed by immunohistochemistry and scored from 0 to 3+ according to 2018 ASCO/CAP HER2 testing guideline. HER2 gene amplification was assessed by florescence in situ hybridization for all the 2+ and 3+ cases as well as 5 of the 0/1+ cases. Among 100 cases, immunohistochemistry scores were 0/1+ in 81 cases, 2+ in 18 cases and 3+ in 1 case. By florescence in situ hybridization, the only 3+ case and 1 of the 2+ cases were HER2-amplified and all 5 of the 0/1+ cases were HER2 nonamplified. Subclonal HER2 overexpression/amplification was identified in 1 of the neoadjuvant cases comprising <10% of the entire tumor. In summary, HER2 overexpression/amplification was found in 2% of TO-HGSC. The 2018 ASCO/CAP HER2 testing guideline in breast cancer can be utilized for TO-HGSC. Future studies are needed to explore HER2-targeted therapies in TO-HGSC and expand the patient population who may benefit from HER2-targeted therapies such as patients with activating mutations in HER2 gene without overexpression/amplification.

Immunophenotypic profile as a predictor of prognosis in advanced ovarian carcinoma

Although proteomic profiles for ovarian epithelial carcinoma (OECa) have been widely investigated, no single marker or set of predictors has been clinically implemented mainly because their reliability and validity have not yet been well established. To establish immunohistochemical (IHC) panels for prognosis prediction of OECa for use in daily pathology practice, the expression patterns of 12 IHC markers, p53, HNF-1β, ARID1A, estrogen receptor-α, progesterone receptor, vimentin, PTEN, PIK3CA, WT1, left-right determination factor, β-catenin, and Ki-67 were investigated using 282 OECas. Hierarchical clustering analysis revealed 7 major immunoprofile groups (IPGs I-VII) that could be used to categorize OECa tumors independent of histotypes. Based on the results of the cluster analysis and protein expression statuses, we further demonstrated the effective classification of OECa tumors into simplified immunoprofile panels using only 4 IHC markers including HNF-1β, p53, ARID1A, and WT1. The tumors in IPG VII with HNF1β+/p53+/ARID1A+ immunophenotype demonstrated a significantly worse overall survival and progression-free survival as compared with the other IPGs. Multivariate Cox regression analysis also revealed that the immunophenotype (HNF1β+/p53+/ARID1A+) and clinical stage were significant and independent prognostic factors for overall survival and progression-free survival in advanced OECa. In conclusion, we identified immunoprofiles in OECa using a panel of 4 IHC markers, which could identify tumors by the immunophenotype that is associated with the most unfavorable prognosis and thus facilitate prognosis prediction of advanced OECa.

CEA/CD3 bispecific antibody MEDI-565/AMG 211 activation of T cells and subsequent killing of human tumors is independent of mutations commonly found in colorectal adenocarcinomas

Individual or combinations of somatic mutations found in genes from colorectal cancers can redirect the effects of chemotherapy and targeted agents on cancer cell survival and, consequently, on clinical outcome. Novel therapeutics with mechanisms of action that are independent of mutational status would therefore fulfill a current unmet clinical need. Here the CEA and CD3 bispecific single-chain antibody MEDI-565 (also known as MT111 and AMG 211) was evaluated for its ability to activate T cells both in vitro and in vivo and to kill human tumor cell lines harboring various somatic mutations commonly found in colorectal cancers. MEDI-565 specifically bound to normal and malignant tissues in a CEA-specific manner, and only killed CEA positive cells. The BiTE® antibody construct mediated T cell-directed killing of CEA positive tumor cells within 6 hours, at low effector-to-target ratios which were independent of high concentrations of soluble CEA. The potency of in vitro lysis was dependent on CEA antigen density but independent of the mutational status in cancer cell lines. Importantly, individual or combinations of mutated KRAS and BRAF oncogenes, activating PI3KCA mutations, loss of PTEN expression, and loss-of-function mutations in TP53 did not reduce the activity in vitro. MEDI-565 also prevented growth of human xenograft tumors which harbored various mutations. These findings suggest that MEDI-565 represents a potential treatment option for patients with CEA positive tumors of diverse origin, including those with individual or combinations of somatic mutations that may be less responsive to chemotherapy and other targeted agents.

Role of HER family members in predicting prognoses in epithelial ovarian cancer: a meta-analysis

AIMS AND BACKGROUND

Human epidermal receptor (HER) family receptors are commonly overexpressed in various human tumors, and their overexpression is thought to play a critical role in tumor progression. The aim of this meta-analysis was to evaluate the prognostic significance of HER family members in epithelial ovarian cancer (EOC).

METHODS

Relevant studies published between January 1, 1980, and April 24, 2013, that evaluated the associations of HER family members with overall survival (OS), progression-free survival (PFS), response to platinum-based chemotherapy, lymph node metastasis, or ascites in EOC were identified via searches of PubMed and EMBASE.

RESULTS

We identified 37 eligible articles that met the inclusion criteria. The results of the meta-analysis revealed that significantly poorer OS of patients with EOC was predicted by high Her-2 expression levels (hazard ratio [HR] 1.69, 95% confidence interval [CI] 1.31-2.19). Furthermore, high Her-2 expression was significantly associated with poor PFS (HR 1.88, 95% CI 1.46-2.41) and an increased risk of ascites (risk ratio 1.21, 95% CI 1.02-1.42).

CONCLUSIONS

High levels of expression of Her-2 are significantly related to poor survival and an increased risk of ascites in patients with EOC. Future prospective cohorts with larger samples are needed to verify the prognostic value of Her-2 expression in EOC.

Apoptosis and molecular targeting therapy in cancer

Apoptosis is the programmed cell death which maintains the healthy survival/death balance in metazoan cells. Defect in apoptosis can cause cancer or autoimmunity, while enhanced apoptosis may cause degenerative diseases. The apoptotic signals contribute into safeguarding the genomic integrity while defective apoptosis may promote carcinogenesis. The apoptotic signals are complicated and they are regulated at several levels. The signals of carcinogenesis modulate the central control points of the apoptotic pathways, including inhibitor of apoptosis (IAP) proteins and FLICE-inhibitory protein (c-FLIP). The tumor cells may use some of several molecular mechanisms to suppress apoptosis and acquire resistance to apoptotic agents, for example, by the expression of antiapoptotic proteins such as Bcl-2 or by the downregulation or mutation of proapoptotic proteins such as BAX. In this review, we provide the main regulatory molecules that govern the main basic mechanisms, extrinsic and intrinsic, of apoptosis in normal cells. We discuss how carcinogenesis could be developed via defective apoptotic pathways or their convergence. We listed some molecules which could be targeted to stimulate apoptosis in different cancers. Together, we briefly discuss the development of some promising cancer treatment strategies which target apoptotic inhibitors including Bcl-2 family proteins, IAPs, and c-FLIP for apoptosis induction.

Class III β-tubulin overexpression in ovarian clear cell and serous carcinoma as a maker for poor overall survival after platinum/taxane chemotherapy and sensitivity to patupilone

OBJECTIVE

Clear cell carcinoma of the ovary is a distinct subtype of epithelial cancer associated with chemoresistance and poor outcome compared with serous papillary carcinomas. Resistance to paclitaxel has been linked to serous papillary overexpression of class III β-tubulin in several human cancers but inadequately characterized among clear cell carcinoma of the ovary. Chemoresistance has also been variably linked to the drug efflux pump p-glycoprotein. Epothilones are microtubule-stabilizing agents with putative activity in paclitaxel-resistant malignancies. In this study, we clarify the relationship between class III β-tubulin and p-glycoprotein expression in clear cell carcinoma of the ovary, clinical outcome, and in vitro responsiveness to patupilone and paclitaxel.

STUDY DESIGN

Class III β-tubulin and p-glycoprotein were quantified by real time polymerase chain reaction in 61 fresh-frozen tissue samples and 11 cell lines. Expression by polymerase chain reaction was correlated with immunohistochemistry and overall survival. IC50 was determined using viability/metabolic assays. Impact of class III β-tubulin down-regulation on IC50 was assessed with small interfering RNAs.

RESULTS

Clear cell carcinoma of the ovary overexpressed class III β-tubulin and p-glycoprotein relative to serous papillary carcinomas carcinomas in fresh-frozen tissues and cell lines. Class III β-tubulin immunohistochemistry reflected real time polymerase chain reaction results and overexpression stratified patients by overall survival. P-glycoprotein correlated with in vitro paclitaxel resistance, but not clinical outcome. Clear cell carcinoma of the ovary were exquisitely sensitive to patupilone in a manner that correlated with class III β-tubulin expression.

CONCLUSION

Class III β-tubulin overexpression in clear cell carcinoma of the ovary discriminates poor prognosis, serves as a marker for sensitivity to patupilone, and may contribute to paclitaxel resistance. Immunohistochemistry reliably identifies tumors with overexpression of class III β-tubulin, and accordingly a subset of individuals likely to respond to patupilone.

Lung resistance-related protein (LRP) expression in malignant ascitic cells as a prognostic marker for advanced ovarian serous carcinoma

PURPOSE

Ovarian serous carcinoma is an aggressive cancer that often presents with metastatic disease. Although primary tumor and established metastatic foci in the omentum are generally compared to identify proteins involved in drug resistance, we investigated a potential bridge, the malignant cells from ascites, as facilitator of drug resistance and recurrence.

METHODS

We evaluated the expression of drug resistance markers P-glycoprotein (P-gp), canalicular multispecific organic anion transporter (MRP2), and lung resistance-related protein (LRP) in malignant cells from ascites and matched omental metastasis from 25 patients with advanced-stage ovarian serous carcinoma who were chemotherapeutic naïve and undergoing initial cytoreductive surgery. Cell viability in vitro, patient response to chemotherapy, and patient survival were correlated with these biomarkers.

RESULTS

Of the 25 patients evaluated for a correlation of LRP to 1-year recurrence, we correctly predicted the 1-year recurrence of 24 patients based solely on the presence of LRP in ascitic tumor cells (p=0.01). P-gp and MRP2 were not expressed in malignant cells of ascites or omental metastases. Malignant cells from ascites had higher expression of LRP and were found to be more resistant to carboplatin treatment than cells from omental metastasis (p=0.00375) by in vitro assay. LRP expression in the malignant cells of ascites correlated with carboplatin resistance (p=0.001) by in vitro assay and recurrence at 1 year (p=0.0125).

CONCLUSIONS

LRP expression in malignant cells of ascites is a promising marker to predict response to first-line chemotherapy in patients with advanced ovarian serous carcinoma.

Lineage targeted MHC-II transgenic mice demonstrate the role of dendritic cells in bacterial-driven colitis

BACKGROUND

Inflammatory bowel disease (IBD) pathogenesis involves an inadequately controlled immune reaction to intestinal microbiota, and CD4(+) T cells, dependent on MHC class II (MHC-II) processing and presentation by antigen-presenting cells (APC), play important roles. The role of professional APC (macrophages and dendritic cells [DCs]) and nonprofessional APC (intestinal epithelial cells [IECs]) in microbial-driven intestinal inflammation remains controversial.

METHODS

We generated transgenic animals on an MHC-II(-/-) genetic background in which MHC-II is expressed on 1) DC via the CD11c promoter (CD11cTg) or 2) IEC via the fatty acid binding protein (liver) promoter (EpithTg). These mice were crossed with Rag2(-/-) mice to eliminate T and B cells (CD11cTg/Rag2(-/-) and EpithTg/Rag2(-/-)). Helicobacter bilis (Hb) infection and adoptive transfer (AT) of naïve CD4 T cells were used to trigger IBD.

RESULTS

CD11cTg/Rag2(-/-) mice infected with Hb+AT developed severe colitis within 3 weeks post-AT, similar to disease in positive control Rag2(-/-) mice infected with Hb+AT. CD11cTg/Rag2(-/-) mice given AT alone or Hb alone had significantly less severe colitis. In contrast, EpithTg/Rag2(-/-) mice infected with Hb+AT developed mild colitis by 3 weeks and even after 16 weeks post-AT had only mild lesions.

CONCLUSIONS

MHC-II expression restricted to DCs is sufficient to induce severe colitis in the presence of T cells and a microorganism such as Hb within 3 weeks of AT. Expression of MHC-II solely on IEC in the presence of a microbial trigger and T cells was insufficient to trigger severe colitis.

CD105/Ki67 coexpression correlates with tumor progression and poor prognosis in epithelial ovarian cancer

AIM

To analyze the expression patterns of CD105 and Ki67 in human epithelial ovarian cancer (EOC) and to evaluate the clinical significance of these two markers in the progression and prognosis in EOC.

MATERIALS AND METHODS

The CD105 and Ki67 protein expression patterns in paraffin-embedded specimens gathered from 166 patients with EOC were detected by immunohistochemistry analysis. The association of CD105 and Ki67 protein expression with the prognosis in EOC was subsequently assessed.

RESULTS

The CD105 and Ki67 proteins were positively expressed in 101/166 (60.8%) and 129/166 (77.7%) of EOC patients, respectively. The CD105 tumors are more likely to have higher tumor grade (P = 0.02). Patients with positive Ki67 staining are more likely to be at the advanced stage of the disease (P = 0.008). Marker CD105 was positively correlated with Ki67 (r = 0.66, P = 0.01). In addition, Ki67 (hazards ratio [HR], 4.8; confidence interval [CI], 1.2-16.6; P = 0.008) and CD105⁺ (HR, 4.1; CI, 1.0-15.2; P = 0.01) were both independent prognostic factors for poor overall survival in EOC patients. Furthermore, combined CD105/Ki67 expression was significantly related to unfavorable overall survival (HR, 16.6; CI, 1.2-128.9; P < 0.001).

CONCLUSIONS

Our results suggest that the CD105 and Ki67 expressions might be involved in the progression of EOC and patient prognosis. A combined detection of CD105/Ki67 coexpression may benefit us in predicting the prognosis in EOC.

EGFR/HER-targeted therapeutics in ovarian cancer

Despite decades of research and evolving treatment modalities, survival among patients with epithelial ovarian cancer has improved only incrementally. During this same period, the development of biologically targeted therapeutics has improved survival for patients with diverse malignancies. Many of these new drugs target the human epidermal growth factor receptor (EGFR/HER/ErbB) family of tyrosine kinases, which play a major role in the etiology and progression of many carcinomas, including epithelial ovarian cancer. While several HER-targeted therapeutics are US FDA approved for the treatment of various malignancies, none have gained approval for the treatment of ovarian cancer. Here, we review the published literature on HER-targeted therapeutics for the treatment of ovarian cancer, including novel HER-targeted therapeutics in various stages of clinical development, as well as the challenges that have limited the use of these inhibitors in clinical settings.

Targeting the epidermal growth factor receptor in epithelial ovarian cancer: current knowledge and future challenges

The epidermal growth factor receptor is overexpressed in up to 60% of ovarian epithelial malignancies. EGFR regulates complex cellular events due to the large number of ligands, dimerization partners, and diverse signaling pathways engaged. In ovarian cancer, EGFR activation is associated with increased malignant tumor phenotype and poorer patient outcome. However, unlike some other EGFR-positive solid tumors, treatment of ovarian tumors with anti-EGFR agents has induced minimal response. While the amount of information regarding EGFR-mediated signaling is considerable, current data provides little insight for the lack of efficacy of anti-EGFR agents in ovarian cancer. More comprehensive, systematic, and well-defined approaches are needed to dissect the roles that EGFR plays in the complex signaling processes in ovarian cancer as well as to identify biomarkers that can accurately predict sensitivity toward EGFR-targeted therapeutic agents. This new knowledge could facilitate the development of rational combinatorial therapies to sensitize tumor cells toward EGFR-targeted therapies.

Inhibition of cell proliferation, vascular endothelial growth factor and tumor growth by albendazole

Vascular endothelial growth factor (VEGF) is the key molecule mediating tumor growth and malignant ascites formation. We recently reported that, in an end stage OVCAR-3 xenograft model, albendazole (ABZ) suppresses ascites formation, but not tumor growth. Hence, in the present study, we assessed the effect of ABZ on in vitro OVCAR-3 cell proliferation plus in vivo tumor growth, however, initiating ABZ treatment at mid stage (3 weeks post cell inoculation) rather than end stage disease. Here, ABZ treatment led to potent inhibition of cell proliferation, VEGF suppression, complete inhibition of ascites formation and most strikingly arrest of tumor growth.

Clinical implications of the ErbB/epidermal growth factor (EGF) receptor family and its ligands in ovarian cancer

The ERBB or EGF receptor (EGFR) proto-oncogene family, which consists of four structurally-related transmembrane receptors (i.e., EGFR, ErbB2, ErbB3, and ErbB4), plays an etiological role in the molecular pathogenesis of cancer and is a key therapeutic target in many types of cancer, including ovarian cancer. These ErbB/EGF receptor tyrosine kinases play important physiologic roles in cell proliferation, survival, adhesion, motility, invasion, and angiogenesis. It is, therefore, not surprising that gene amplification, genetic mutation, and altered transcription/translation result in aberrant ErbB/EGF receptor expression and/or signal transduction, contributing to the development of malignant transformation. Clinically, the diagnostic, prognostic, and theragnostic significance of any single ErbB receptor and/or ErbB ligand is controversial, but generally, ErbB receptor overexpression has been correlated with poor prognosis and decreased therapeutic responsiveness in ovarian cancer patients. Thus, anticancer agents targeting ErbB/EGF receptors hold great promise for personalized cancer treatment. Yet, challenges remain in designing prospective clinical trials to assess the clinical utility of ErbB receptors and their ligands to diagnose cancer; to predict progression-free and overall survival, therapeutic responsiveness, and disease recurrence; and to monitor treatment responsiveness. Here, we review the tissue expression and serum biomarker studies that have evaluated the diagnostic, prognostic, and theragnostic utility of ErbB/EGF receptors, their circulating soluble isoforms (sEGFR/sErbBs), and their cognate ligands in ovarian cancer patients.

HER2 status in ovarian carcinomas: a multicenter GINECO study of 320 patients

BACKGROUND

Despite a typically good response to first-line combination chemotherapy, the prognosis for patients with advanced ovarian cancer remains poor because of acquired chemoresistance. The use of targeted therapies such as trastuzumab may potentially improve outcomes for patients with ovarian cancer. HER2 overexpression/amplification has been reported in ovarian cancer, but the exact percentage of HER2-positive tumors varies widely in the literature. In this study, HER2 gene status was evaluated in a large, multicentric series of 320 patients with advanced ovarian cancer, including 243 patients enrolled in a multicenter prospective clinical trial of paclitaxel/carboplatin-based chemotherapy.

METHODOLOGY/PRINCIPAL FINDINGS

The HER2 status of primary tumors and metastases was evaluated by both immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) analysis of paraffin-embedded tissue on conventional slides. The prognostic impact of HER2 expression was analyzed. HER2 gene was overexpressed and amplified in 6.6% of analyzed tumors. Despite frequent intratumoral heterogeneity, no statistically significant difference was detected between primary tumors and corresponding metastases.

CONCLUSIONS/SIGNIFICANCE

Our results show that the decision algorithm usually used in breast cancer (IHC as a screening test, with equivocal results confirmed by FISH) is appropriate in ovarian cancer. In contrast to previous series, HER2-positive status did not influence outcome in the present study, possibly due to the fact that patients in our study received paclitaxel/carboplatin-based chemotherapy. This raises the question of whether HER2 status and paclitaxel sensitively are linked.

Effect of HER-2/neu overexpression on chemoresistance and prognosis in ovarian carcinoma

AIM

To investigate the effect of HER-2/neu protein overexpression on chemoresistance and prognosis in patients with epithelial ovarian carcinoma.

METHODS

A total of 141 ovarian carcinoma tissues surgically resected between 1987 and 2003 were assessed by immunohistochemistry (IHC). The characteristic of the patients and immunohistochemical results were compared by chi2-test. Survival analysis was performed by the Kaplan-Meier method and the log-rank test.

RESULTS

HER-2/neu overexpression was detected in 18 cases (12.8%). There were no significant differences in histopathological subtypes (P = 0.3550), FIGO stages (P = 0.8858), or residual tumor size at first surgery (P = 0.6607) between the cases with HER-2/neu overexpression and the cases without HER-2/neu overexpression. Among the 58 cases which responded to chemotherapy, only five cases (8.6%) showed HER-2/neu overexpression. However, among the 38 cases which did not respond to chemotherapy, eight cases (21.1%) showed HER-2/neu overexpression. Overexpression of HER-2/neu had a tendency to relate with chemoresistance of epithelial ovarian carcinoma, but there were no statistically significant differences (P = 0.0817). No association was observed between HER-2/neu overexpression and cumulative survival rate (P = 0.4970).

CONCLUSIONS

The results of the current study show that although HER-2/neu overexpression has a tendency to be associated with chemoresistance, it can not be a prognostic factor for the patients with epithelial ovarian carcinoma.

Alterations in the p53 pathway and prognosis in advanced ovarian cancer: a multi-factorial analysis of the EORTC Gynaecological Cancer group (study 55865)

PURPOSE

The study was designed to determine independent prognostic variables in suboptimally debulked advanced ovarian cancer patients entered in the randomised phase III study EORTC 55865.

EXPERIMENTAL DESIGN

Retrospectively collected paraffin blocks from 169 patients with stages IIb-IV epithelial ovarian cancer, taken at primary debulking surgery, were analysed. All patients were treated with cyclophosphamide and cisplatin (CP), and followed up for a median of 10 years. Expression of p53, bcl-2, P21, Ki-67 and HER-2 status was assessed by immunohistochemistry (IHC).

RESULTS

Expression of p21, a downstream effector of the p53 gene, was found to be a favourable prognostic factor for survival (HR 0.58, CI 0.36-0.94, p=0.025) in addition to FIGO stage (HR 1.54, CI 1.08-2.21, p=or<0.02). For progression free survival (PFS), both p21 (HR 0.52) and Ki-67 (HR 0.6) were significant factors.

CONCLUSION

P21 overexpression is a positive prognostic factor for survival and PFS in advanced ovarian carcinoma with residual lesions of more than 1 cm.

Survival analysis in advanced epithelial ovarian carcinoma in relation to proliferative index of MIB-1 immunostaining

AIM

To evaluate the survival of patients with advanced epithelial ovarian carcinoma in relation to MIB-1 immunostaining, to determine the association between MIB-1 and clinicopathologic variables, and to identify an appropriate cut-off point for MIB-1 immunostaining as a prognostic marker.

METHODS

We retrospectively reviewed the medical records of women diagnosed with advanced epithelial ovarian carcinoma during 1987-1998. The paraffin-embedded tissue of recruited women was stained with MIB-1 immunostaining for review.

RESULTS

The records of 105 patients were included. The percentage staining of MIB-1 ranged from 0.3 to 100%, with a median of 11.9%. MIB-1 staining was generally higher in serous tumors than in other types (P = 0.048), but was not associated with other potential prognostic indicators. The 5-year survival rate among advanced epithelial ovarian carcinoma patients was 25.7%, while that in the high MIB-1 (greater than or equal to median) and low MIB-1 (less than median) patients was 15.1% (95% confidence interval [CI] = 7.1-26.0) and 36.5% (95% CI = 23.8-49.4), respectively. Median survival times in the two groups were 1.8 years and 3.0 years, respectively (P < 0.008). Division of the MIB-1 staining percentage into quartiles showed that the risk of death increased from the first to the second quartile (>/=7.6 to <11.9%, hazard ratio = 2.36, 95% CI = 1.22-4.54) with no further increase in higher quartiles.

CONCLUSION

Among patients with advanced epithelial ovarian carcinoma, MIB-1 immunostaining was higher in serous than in other histologic types. Levels of MIB-1 staining above the cut-off point of 7.6% had significantly poorer survival.

Dual infection with Helicobacter bilis and Helicobacter hepaticus in p-glycoprotein-deficient mdr1a-/- mice results in colitis that progresses to dysplasia

Patients with inflammatory bowel disease (IBD) are at increased risk for developing high-grade dysplasia and colorectal cancer. Animal IBD models that develop dysplasia and neoplasia may help elucidate the link between inflammation and colorectal cancer. Mdr1a-/- mice lack the membrane efflux pump p-glycoprotein and spontaneously develop IBD that can be modulated by infection with Helicobacter sp: H. bilis accelerates development of colitis while H. hepaticus delays disease. In this study, we determined if H. hepaticus infection could prevent H. bilis-induced colitis. Unexpectedly, a proportion of dual-infected mdr1a-/- mice showed IBD with foci of low- to high-grade dysplasia. A group of dual-infected mdr1a-/- animals were maintained long term (39 weeks) by intermittent feeding of medicated wafers to model chronic and relapsing disease. These mice showed a higher frequency of high-grade crypt dysplasia, including invasive adenocarcinoma, possibly because H. hepaticus, in delaying the development of colitis, allows time for transformation of epithelial cells. Colonic epithelial preparations from co-infected mice showed increased expression of c-myc (5- to 12-fold) and interleukin-1alpha/beta (600-fold) by real-time polymerase chain reaction relative to uninfected wild-type and mdr1a-/- animals. This animal model may have particular relevance to human IBD and colorectal cancer because certain human MDR1 polymorphisms have been linked to ulcerative colitis and increased risk for colorectal cancer.

Expression of progesterone receptor is a favorable prognostic marker in ovarian cancer

OBJECTIVE

Receptors for estrogen (ER), progesterone (PR), or androgen (AR) are predictive and prognostic markers of malignancy of multiple endocrine organs, including endometrial and breast cancer. However, the role of ERs, PRs, or ARs in the carcinogenesis of ovarian cancer, another sex hormone-dependent malignancy, is still controversial despite numerous studies that have attempted to determine their role. The disagreement in the findings may result from the fact that the numbers of tumor samples in studies have been small and that different immunohistochemical methods have been used that can introduce variation in the scoring of the histology. We therefore examined the pattern of expression of ERs, PRs, and ARs in a large number of samples of primary ovarian carcinoma by using a tissue microarray technique.

METHODS

We constructed a tissue microarray with 322 samples of primary ovarian carcinoma obtained at surgery performed at The University of Texas M. D. Anderson Cancer Center between 1990 and 2000. Immunohistochemistry studies were performed by using the immunoperoxidase technique against primary antibodies (ER, PR, and AR).

RESULTS

ERs, PRs, and ARs were differently expressed in different histotypes of ovarian cancer: ERs were expressed in 77.3% of all cases but more highly expressed in serous and endometrioid types; PRs were expressed in 26.2% of all cases but most highly expressed in the endometrioid type < 64.2%; and ARs were expressed in 43.7% of all cases but were most highly expressed in serous (47.5%) carcinomas. Of particular importance, the expression of PRs, but not ERs or ARs, was associated with better survival (P < 0.0001) in univariate and multivariate analyses.

CONCLUSIONS

The PR is an independent marker, with its overexpression associated with a favorable prognosis in women with ovarian cancer.

Mutational spectrum of p53 mutations in primary breast and ovarian tumors

Breast and ovarian cancers, like other cancers, occur due to genetic damage. Research aimed to determine the specific genes involved in the development of breast and ovarian cancers will help to understand how normal breast and ovarian epithelial cells escape regulation of proliferation, apoptosis and senescence. It was determined that approximately 10% of ovarian cancers and 20-30% of breast cancers arise in women who have inherited mutations in cancer susceptibility genes such as BRCA1, BRCA2 and other DNA repair genes. The ability to perform genetic testing permits the identification of women at increased risk who can then be offered preventive strategies. The vast majority of ovarian and breast cancers are sporadic, presumably resulting from the accumulation of genetic damage over lifetime. Several genes involved in breast and ovarian carcinogenesis have been identified, most notably the p53 tumor suppressor. The recent availability of expression microarrays has facilitated the simultaneous screening of thousands of genes and this will extend further the understanding of molecular events involved in the dynamic development of ovarian and breast cancers. Then, all this knowledge could be translated into effective screening, surveillance, prevention, and treatment strategies in the future.

Molecular mechanisms of drug resistance

Resistance to chemotherapy limits the effectiveness of anti-cancer drug treatment. Tumours may be intrinsically drug-resistant or develop resistance to chemotherapy during treatment. Acquired resistance is a particular problem, as tumours not only become resistant to the drugs originally used to treat them, but may also become cross-resistant to other drugs with different mechanisms of action. Resistance to chemotherapy is believed to cause treatment failure in over 90% of patients with metastatic cancer, and resistant micrometastic tumour cells may also reduce the effectiveness of chemotherapy in the adjuvant setting. Clearly, if drug resistance could be overcome, the impact on survival would be highly significant. This review focuses on molecular mechanisms of drug resistance that operate to reduce drug sensitivity in cancer cells. Drug resistance can occur at many levels, including increased drug efflux, drug inactivation, alterations in drug target, processing of drug-induced damage, and evasion of apoptosis. Advances in DNA microarray and proteomic technology, and the ongoing development of new targeted therapies have opened up new opportunities to combat drug resistance. We are now able to characterize the signalling pathways involved in regulating tumour cell response to chemotherapy more completely than ever before. This will facilitate the future development of rational combined chemotherapy regimens, in which the newer targeted therapies are used in combination with cytotoxic drugs to enhance chemotherapy activity. The ability to predict response to chemotherapy and to modulate this response with targeted therapies will permit selection of the best treatment for individual patients.

Class III β-Tubulin Overexpression Is a Prominent Mechanism of Paclitaxel Resistance in Ovarian Cancer Patients

The vast majority of women with advanced ovarian cancer will ultimately relapse and develop a drug-resistant disease with an overall 5-year survival of &lt;50%. Unfortunately, the mechanisms of drug resistance actually operating in patients are still unknown. To address this issue, in 41 patients affected by advanced ovarian cancer the three main mechanisms of paclitaxel resistance were investigated: overexpression of MDR-1 gene, point mutations at prominently expressed α-tubulin and β-tubulin genes and selective alterations in the expression of β-tubulin isotypes. MDR-1 and the β-tubulin isotypes expression were evaluated by semiquantitative and real-time PCR. On the same specimens, quantitative immunohistochemistry was also done in the tumor area. No statistically significant changes of MDR-1 expression were noticed between the sensitive and resistant patients either at the mRNA or protein level. The tubulin mutations for the ubiquitous α-tubulin and β-tubulin genes were evaluated by automated DNA sequencing, and in all patients, no mutations were detected in both resistant and sensitive cases. With regard to the expression of tubulin isoforms, a statistically significant up-regulation of class III β-tubulin was found in the resistant subset. It is worth noting that this statistically significant increase of the expression of class III β-tubulin was detectable at the mRNA and protein level. By a direct comparison of the three main known mechanisms of paclitaxel resistance, this study indicates that overexpression of class III β-tubulin is the most prominent mechanism of paclitaxel resistance in ovarian cancer.

Type IV collagen and CD44v6 expression in benign, malignant primary and metastatic ovarian tumors: correlation with Ki-67 and p53 immunoreactivity

OBJECTIVE

Loss of basement membrane (BM) components, such as type IV collagen has been demonstrated in ovarian cancer, but the associations with other molecules like CD44v6, involved in metastatic process of ovarian carcinoma, have not been fully analyzed. This study investigates the expression of type IV collagen, CD44v6 molecule in correlation with p53 and Ki-67 presence in primary and metastatic lesion of ovarian carcinoma to define their role in metastases of ovarian carcinoma.

METHODS

The expression of type IV collagen, CD44v6, p53, and Ki-67 was evaluated on frozen tissue sections from primary ovarian tumors (malignant n = 37, benign n = 16), metastatic lesions (n = 29) and ascitic fluid cells (n = 28). Protein expression of all studied biomarkers was evaluated in a subset of specimens using immunohistochemistry (IHC).

RESULTS

Type IV collagen expression in the primary ovarian carcinoma was positively correlated with International Federation of Gynecology and Obstetrics (FIGO) stage and tumor grade. Significant difference was observed for type IV collagen immunoreactivity in carcinoma cells in effusions when compared to corresponding primary tumors (P < 0.001) and metastatic lesions (P < 0.001). Likewise down-regulation of type IV collagen expression was seen in primary ovarian carcinomas (P = 0.01), ascitic fluid cells (P < 0.001), and metastases (P = 0.003) when compared to benign ovarian neoplasms. CD44v6 expression was detected in a comparable percentage of primary carcinomas (51%) and metastatic lesions (52%). In cells isolated from ascitic fluid, CD44v6 immunopositivity was observed in 43% of cases. A comparative analysis of primary and metastatic tumors and carcinoma cells in effusion did not reveal differences in expression of CD44v6. Positivity of CD44v6 was found in 2/16 (12%) of benign ovarian neoplasms. There were no significant differences between CD44v6 expression in benign neoplasms compared to primary malignant tumors and metastases (P > 0.05). CD44v6 expression in primary ovarian carcinomas was associated with higher tumor grade (P = 0.01) and histological type of tumors (P = 0.01). An inverse relationship of type IV collagen expression with p53 and CD44v6 positivity in benign and malignant ovarian tumors was found (P > 0.01). Type IV collagen expression was inversely correlated with p53 status (P = 0.03) in metastatic lesions. A slight trend toward an inverse correlation between Ki-67 and type IV collagen expression was observed in both benign and malignant ovarian tumors and metastases.

CONCLUSIONS

Our data suggest that observed inverse correlation of type IV collagen expression with p53, CD44v6, and slight with Ki-67 positivity in primary benign and malignant tumors indicates that these molecules may cooperate in the invasion and progression of ovarian carcinomas.

Quantitative c-erbB-2 but not c-erbB-1 mRNA expression is a promising marker to predict minor histopathologic response to neoadjuvant radiochemotherapy in oesophageal cancer

We examined the potential of quantitative epidermal growth factor receptor (EGFR, synonym: c-erbB-1) and c-erbB-2 (synonym: HER2/neu) mRNA expression to predict minor or major histopathologic response to neoadjuvant radiochemotherapy (cis-platinum, 5-FU, 36 Gy), followed by radical surgical resection, in patients with oesophageal cancer. Tissue samples were collected by endoscopic biopsy prior to treatment. RNA was isolated from biopsies and quantitative real-time reverse transcriptase–polymerase chain reaction assays were performed to determine c-erbB-1 and c-erbB-2 mRNA expression. Relative expression (tumour/paired normal tissue ratio standardised for β-actin) was calculated for EGFR and c-erbB-2 mRNA. Expression levels were correlated with the objective histopathologic response in resected specimens. Histomorphologic regression was defined as major response when resected specimens contained less than 10% of residual vital tumour cells, or in case a pathologically complete response was achieved. Expression of c-erbB-1 mRNA was not associated with the degree of histomorphological response. In contrast, the relative expression levels of c-erbB-2 mRNA >1 were not associated with major histopathologic responses (sensitivity 41.6%, specificity 100%), and 10 out of 36 (28%) patients could be unequivocally identified, whose tumours did not respond well to the delivered neoadjuvant radiochemotherapy (P<0.01). Quantitative expression levels of c-erbB-2, but not c-erbB-1 mRNA, in pretreatment biopsies appear to predict minor histopathologic response to our neoadjuvant radiochemotherapy protocol. This test could be used to prevent expensive, noneffective and potentially harmful therapies in approximately one-fourth of our patients, and leads to a more individualised type of combined modality treatment.

A new prognostic model comprising p53, EGFR, and tumor grade in early stage epithelial ovarian carcinoma and avoiding the problem of inaccurate surgical staging

Epithelial ovarian carcinoma rarely occurs because of a single event. Therefore, no single biological tumor factor will give accurate prognostic information for all ovarian cancer patients. On the other hand, a combination of two or more independent factors may yield an improved overall prognostic index. Because FIGO stage is included in most of the previously presented models, inaccurate surgical staging in patients with apparently early disease has been a problem. In a series of 226 patients with epithelial ovarian carcinomas in FIGO stages IA-IIC, a number of clinicopathological factors (age, FIGO stage, histopathologic type, and tumor grade) were studied in relation to the biological factors p53 and epidermal growth factor receptor (EGFR), important regulators of the apoptosis and mitosis. Immunohistochemical techniques were used. All patients received adjuvant radiotherapy or chemotherapy after the primary surgery. Expression of p53 was significantly associated with the tumor grade and disease-free survival (DFS). EGFR expression was also associated with DFS. In a Cox multivariate analysis, tumor grade, p53 status, and EGFR status were all independent and significant prognostic factors with regard to DFS. A prognostic model was proposed using these factors. A low-risk group, an intermediate-risk group, and a high-risk group were defined. DFS amounted to 89% in the low-risk group (grades 1-2, p53-negative, and EGFR-negative), 66% in the intermediate-risk group (grade 3, p53-negative, and EGFR-negative or grades 1-2, p53-positive or EGFR-positive) and 39% in the high-risk group (grade 3, p53-positive, and EGFR-positive).

HER-2 overexpression is an independent marker of poor prognosis of advanced primary ovarian carcinoma: a multicenter study of the GINECO group

BACKGROUND

Despite numerous studies, no biological marker has been identified that accurately predicts prognosis of advanced ovarian cancer. Tumors from a homogeneous population of 117 patients with a stage III/IV ovarian cancer, enrolled in a multicenter prospective GINECO clinical trial were analyzed retrospectively.

PATIENTS AND METHODS

All patients received the same platinum-based combination therapy and were followed-up for a median of 68 months. Tumor expression of Ki67, BCL-2, BAX, P53 or c-erbB-2 proteins was evaluated immunohistochemically on paraffin-embedded tissues and their prognostic impact analyzed.

RESULTS

The median rate of Ki67-positive nuclear area was 30%. BCL-2, BAX and P53 proteins were expressed in 52, 54 and 71% of the tumors, respectively, while HER-2 protein was overexpressed in 16%. Only HER-2 overexpression was significantly associated with shorter progression-free survival and overall survival. According to our multivariate analysis, the HER-2 prognostic impact was independent of classical clinical prognostic factors.

CONCLUSION

HER-2 appeared to influence the outcome of advanced ovarian cancer patients included in a clinical trial with prolonged follow-up, thereby suggesting that HER-2 is a potential target for treatment of this cancer.

Expression of multidrug resistance-1 protein inversely correlates with paclitaxel response and survival in ovarian cancer patients: a study in serial samples

OBJECTIVES

The role of MDR1 in clinical paclitaxel resistance remains poorly characterized. This study sought to identify the incidence and significance of P-glycoprotein (P-gp) over-expression on survival, tumor response to paclitaxel and the effect of prior cytotoxic exposure on P-gp expression in patients with paired primary and recurrent ovarian cancer samples.

METHODS

Retrospective survival analysis. P-gp expression was evaluated immunohistochemically with antibodies c494 and c219.

RESULTS

Thirty-two patients were identified from the tumor registry. Median interval between primary and secondary surgery was 17.9 (5.7-40.9) months. Only five primary tumors (16%) demonstrated +++ staining for P-gp. First-line treatment contained paclitaxel in 17 patients (53%) and 26 patients (81%) had been exposed to P-gp exportable chemotherapy before second surgery. Only seven of the recurrent tumors (22%) were +++. Only one of seven (14% (95% CI 0-46%)) recurrent tumors with ++ or +++ staining responded to subsequent paclitaxel, while 8 of 10 (80% (CI 46-100%)) recurrent tumors with 0/+ staining responded (P = 0.025). In multivariate analysis of outcome following second surgery, response to paclitaxel (P = 0.004) and P-gp over-expression (P < 0.001) were significant predictors of survival.

CONCLUSIONS

De novo strong P-gp over-expression is uncommon, appears to change little over time or with prior exposure to chemotherapy. However, P-gp over-expression is a significant prognostic factor, and at the time of disease, relapse is inversely correlated with tumor response to paclitaxel.

Drug resistance reversal--are we getting closer?

Clinical drug resistance is a major barrier to overcome before chemotherapy can become curative for most patients presenting with metastatic cancer. Rational attempts to tackle clinical drug resistance need to be based on an understanding of the mechanisms involved; these are likely to be complex and multifactorial, and may be due to inadequate drug exposure or alterations in the cancer cell itself. This article reviews a number of strategies used to tackle drug resistance, focussing on work in our institution related to the treatment of ovarian cancer and resistance to platinum and taxane-based chemotherapy. Further progress towards drug resistance reversal will require a three-pronged approach, namely: the development of novel cytotoxics which exploit selectively expressed targets; modulation of resistance to conventional agents and, most importantly, a serious attempt to understand resistance mechanisms in tumour samples taken both pre- and post-chemotherapy.

Influence of surgery and postoperative therapy and tumor characteristics on patient prognosis in advanced ovarian carcinomas

OBJECTIVES

The prognosis in advanced ovarian cancer depends on clinical, morphological, biological and therapeutic variables. However, little is known about their real influences and interrelationships.

STUDY DESIGN

One hundred and nineteen long-term, follow-up patients with advanced ovarian carcinoma were analyzed. Overall survival was related to the extent of debulking surgery, response to chemotherapy and several clinicomorphological, histopathological, and immunohistochemical variables.

RESULTS

Among all variables, both radical surgery and response to chemotherapy exerted the greatest influence on patient prognosis as shown in both univariate and multifactorial analyses. Most established prognostic factors were of minor importance. Success of chemotherapy correlated with lower residual tumor volume, CA125 expression, FIGO-stage, and serous tumor type.

CONCLUSION

Prognosis and chemotherapeutic success in advanced ovarian cancer seem to be interrelated and may be influenced by the intensity of surgical interventions. This demands for greatest cytoreduction during initial surgery and correction for residual tumor volume and success of therapy in studies of prognostic factors.

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.

Cisplatin, doxorubicin and paclitaxel induce mdr1 gene transcription in ovarian cancer cell lines

The clinical observation of the multidrug resistance (MDR) phenotype is often associated with overexpression of the mdrl gene, in particular with respect to ovarian cancer. However, until now the mdrl-inducing potential of commonly used antineoplastics has been only incompletely explored. We performed short-term cultures of six ovarian cancer cell lines (MZOV4, EF027, SKOV3, OAW42, OTN14, MZOV20) exposed to either blank medium or cisplatin, doxorubicin or paclitaxel at concentrations related to the clinically achievable plasma peak concentration. A highly specific quantitative real-time RT-PCR was used to detect the Mdr1 transcripts. Mdrl mRNA contents were calibrated in relation to coamplified GAPDH mRNA. Mdrl mRNA was detectable in each cell line. In 13 out of 18 assays (72%) the specific anticancer drug being tested induced mdr1 transcription. No decrease in mdr1 mRNA concentration was observed. Our data suggest that mdr1 induction by antineoplastics is one of the reasons for failure of ovarian cancer therapy but may vary individually.

A review of p53 expression and mutation in human benign, low malignant potential, and invasive epithelial ovarian tumors

BACKGROUND

In the current study, the authors present pooled data from studies that investigated p53 protein expression and/or mutation in human epithelial ovarian tumors.

METHODS

The English literature in the MEDLINE, PubMed, and Ingenta databases was searched to the end of the year 2000 to identify relevant studies. Data were pooled across eligible studies, and the prevalence of p53 expression and mutation among benign, low malignant potential (LMP), and invasive tumors was determined. Prevalence estimates by tumor histology, International Federation of Gynecology and Obstetrics (FIGO) stage, and grade also were calculated.

RESULTS

The pooled prevalence estimate for p53 overexpression among epithelial ovarian carcinomas was 51% (95% confidence intervals [95% CI], 50-53%) compared with 17% (95% CI, 15-20%) among LMP tumors and 7% (95% CI, 5-10%) among benign tumors. p53 mutation prevalence estimates were 45% (95% CI, 42-47%), 5% (95% CI, 2-9%), and 1% (95% CI, 0-5%), respectively, for invasive, LMP, and benign tumors. The prevalence of these p53 abnormalities was found to be associated positively with increasing tumor grade and stage. Differences based on histologic subtype also were found.

CONCLUSIONS

Although these pooled estimates might appear to offer support for various hypotheses regarding the role of p53 in ovarian carcinoma, the limitations inherent in these data hamper the interpretation of the significance of any of the findings. Future studies will require innovative methods to address the limitations of many previous investigations and more comprehensive investigation into defective tumor suppression mechanisms.

Cyclooxygenase-2 (COX-2), epidermal growth factor receptor (EGFR), and Her-2/neu expression in ovarian cancer

OBJECTIVES

Cyclooxygenase-2 (COX-2) seems to be involved in critical steps of cancer onset and progression. Abnormalities of epidermal growth factor receptor (EGFR) and Her-2/neu have been actively investigated in ovarian cancer and associated with unfavorable clinical outcome. The involvement of COX-2 in ErbB family pathways has been proposed. We investigated by immunohistochemistry the expression of COX-2, EGFR, and Her-2/neu in a series of advanced primary ovarian cancers.

METHODS

The study included 76 consecutive stage IIIC-IV ovarian cancer patients with measurable disease after first surgery. Immunohistochemistry was performed on paraffin-embedded sections with rabbit antiserum against COX-2, murine monoclonal antibody (MoAb) 300G9 against Her-2/neu, and monoclonal antibody 108 against EGFR.

RESULTS

No association among COX-2, EGFR, and HER-2/neu was found. COX-2 positivity was found in a statistically significant higher percentage of unresponsive cases (80.0%) than in patients responding to chemotherapy (35.7%) (P = 0.0008). The association between COX-2 positivity and poor chance of response to treatment was retained in multivariate analysis. In the subgroup of patients who underwent explorative laparotomy COX-2-positive cases showed a shorter overall survival (P = 0.049).

CONCLUSIONS

COX-2 could represent a possible new marker of sensitivity to platin-based chemotherapy in ovarian cancer. The lack of association of COX-2 with EGFR or Her-2/neu suggests that the ability of COX-2 to predict tumor sensitivity to chemotherapy is not dependent on EGFR or Her-2/neu status and could be independently associated with prognosis. In this context, the availability of agents able to specifically interfere with COX-2, Her-2/neu, or EGFR tyrosine kinase is of potential interest.

Molecular events associated with dysplastic morphologic transformation and initiation of ovarian tumorigenicity

BACKGROUND

Disabled-2 (Dab2), a candidate tumor suppressor of ovarian carcinoma, frequently (around 80%) loses its expression in ovarian tumors. Expression of exogenous Dab2 in tumor cell lines negatively regulates growth and suppresses the downstream signal of the Ras/mitogen activated protein kinase mitogenic pathway. The inactivation of Dab2 is believed to be an early event in ovarian tumorigenicity.

METHODS

The authors analyzed the correlation among expression of Dab2, presence of basement membrane (collagen IV and laminin), morphologic alteration of the surface epithelial cells, and expression of the mitotic index marker Mib-1 in 50 archived ovarian tumors by an immunohistochemical approach. The stainings of Dab2, Mib-1, collagen IV, and laminin in premalignant lesions bordering both normal and neoplastic ovarian surface epithelium from adjacent slides were analyzed in 50 ovarian tumors.

RESULTS

In these 50 ovarian tumors, the percentage of Mib-1 positive tumor cells distributed in a wide range, from 1% to 75%, and there has no strong correlation with the expression of Dab2. However, in the premalignant regions bordering tumor and normal ovarian surface epithelium, the loss of Dab2 expression closely correlated with the dysplastic morphologic transition and Mib-1 expression of the ovarian surface epithelial cells. In 20 foci in 12 out of the 50 tumors, a transition from normal to neoplastic morphology within a contiguous epithelium was observed, and in all cases the morphologic change correlated with the loss of Dab2 staining. In addition, the collagen and laminin staining of the basement membrane were absent or weakened in pre-malignant epithelium prior to loss of Dab2 expression in all these 20 cases. Nevertheless, collagen IV and laminin were detectable in established adenomas on the same tumor slides.

CONCLUSIONS

The loss of Dab2 is closely associated with the transition of ovarian surface epithelial cells to premalignant states and is likely involved in the initiation of ovarian tumorigenicity. Transient loss of collagen IV and laminin in the basement membrane of the premalignant epithelium and subsequent inactivation of Dab2 are common early events associated with tumorigenicity of the ovarian surface epithelium.

Topoisomerase II immunostaining as a prognostic marker for survival in ovarian cancer

OBJECTIVE

This study aimed to evaluate topoisomerase II compared to Ki-67 expression as a marker for tumor behavior and for prognosis of patients with ovarian cancer.

METHODS

In order to screen for potential prognostic markers, two groups of patients with advanced stage (FIGO stages III and IV) epithelial ovarian carcinoma were selected based on differences in survival (mean survival, 11 years versus 2 years). Pathology slides were reviewed, and immunohistochemistry using antibodies to topoisomerase II and Ki-67 was performed on the original cell blocks. No patients were lost to follow-up.

RESULTS

Detectable expression of topoisomerase II was present in 70.0 +/- 30.3% of cells in patients with rapidly progressing disease, compared to only 12.3 +/- 12.4% of cells in long-term survivors (P = 0.0001). Ki-67 expression was also more frequent in short-term survivors compared to long-term survivors, but the difference was less prominent than with topoisomerase II (P = 0.01). Specificity and sensitivity as prognostic factors reached 88.2 and 93.8% for topoisomerase II, compared to 55.6 and 88.2% for Ki-67.

CONCLUSIONS

Topoisomerase II expression as detected by immunohistochemistry in tumor samples emerged as a promising clinically relevant biomarker for survival in advanced epithelial ovarian cancer.

Evaluation of chemoresistance markers in women with epithelial ovarian carcinoma

OBJECTIVE

Preliminary studies have suggested that lung resistance protein (LRP), multidrug resistance protein (MRP), and p27 may be useful markers of chemoresistance. Our goal was to evaluate the expression of LRP, MRP, and p27 in normal ovaries and chemosensitive and chemoresistant ovarian carcinomas.

METHODS

Fourteen women with normal ovaries and fifty women with epithelial ovarian carcinoma who underwent cytoreductive surgery from 1996 through 1998 had specimens stained with immunocytochemistry for LRP, MRP, and p27. All women received paclitaxel/platinum-based chemotherapy. Twenty-nine women had a disease-free survival (DFS) of at least 12 months after completion of chemotherapy (sensitive) and 21 women had persistent disease during treatment (resistant).

RESULTS

Evaluation of LRP expression revealed significant differences between the normal ovaries and cancers in both the epithelial (57% vs 90%, P = 0.03) and stromal (86% vs 32%, P = 0.001) components. Evaluation of MRP expression revealed significant differences between normal ovaries and cancers in the epithelial component (7% vs 66%, P = 0.001) but not in the stromal component (14% vs 4%, P = 0.1). Evaluation of p27 revealed significant reductions in expression in cancers compared with normal ovaries for both the epithelial (90% vs 55%, P = 0.02) and stromal (88% vs 5%, P = 0.001) components. Comparison between the chemosensitive and chemoresistant groups revealed no significant differences in expression of LRP and MRP, in either the epithelial or stromal component, but significantly lower levels of p27 were expressed in the epithelial component of the chemoresistant group (P = 0.01).

CONCLUSIONS

The expression of LRP, MRP, and p27 is significantly different in ovarian cancers compared with normal ovaries. Low levels of p27 expression are associated with chemoresistance; however, LRP and MRP expression are not prognostic for chemosensitivity.

E-Cadherin complex protein expression and survival in ovarian carcinoma

OBJECTIVE

The aim of this study was to analyze the correlation between expression of E-cadherin complex proteins, epidermal growth factor receptor (EGFR), and c-erbB-2 and disease outcome in advanced-stage ovarian carcinomas.

METHODS

Sections from 75 primary ovarian carcinomas (=37) and metastatic lesions (=38) from 45 patients diagnosed with advanced-stage ovarian carcinoma (FIGO stage III-IV) were immunostained and evaluated for staining pattern, extent, and intensity. Patients were divided in two groups based on disease outcome. Long-term survivors (21 patients) and short-term survivors (24 patients) were defined using a double cutoff of 36 months for disease-free survival (DFS) and 60 months for overall survival (OS). Mean follow-up period was 70 months. The mean values for DFS and OS were 109 and 125 months for long-term survivors, as compared to 3 and 21 months for short-term survivors, respectively.

RESULTS

Comparison of all primary and metastatic lesions showed upregulation of gamma-catenin protein expression in the latter (P = 0.05). When segregated according to disease outcome, the expression of all studied proteins, with the exception of EGFR, was more diffuse in tumors of short-term survivors. The presence of cytoplasmic staining for c-erbB-2 was associated with poor survival in the entire cohort (P = 0.007), as well as in primary tumors alone (P = 0.003), in survival analysis. Similar results were seen in the evaluation of primary tumors for gamma-catenin (P = 0.002).

CONCLUSIONS

gamma-Catenin, and possibly c-erbB-2, are valid markers of poor survival in advanced-stage ovarian carcinoma.

Biomarker conservation in primary and metastatic epithelial ovarian cancer

PURPOSE

The aim of this study was to compare the overexpression of specific biomarkers in primary advanced and recurrent epithelial ovarian cancers.

METHODS

Biomarker expression by epithelial ovarian cancer specimens from primary and metastatic sites was examined by immunohistochemistry and flow cytometry. Biomarker expression by subpopulations of tissues consisting of matched pairs of synchronous and metachronous lesions was also studied.

RESULTS

A total of 3173 epithelial ovarian cancer specimens were retrieved from women with FIGO Stage III/IV disease. These included lesions from 1036 primary and 2137 metastatic sites. The percentages of biomarker expression for primary and metastatic lesions, respectively, were MDR1, 12 and 10%; p53, 55 and 60%; HER2, 12 and 11%; EGF-R, 26 and 33%; increased microvessel counts (CD31), 21 and 36%. Approximately 73% of both primary and metastatic specimens were aneuploid, and approximately 57% of both sets had an S-phase fraction >7%. Only EGF-R and CD31 expression were found to be significantly different between the primary and metastatic tumors (P < 0.05). Of the paired synchronous cases (n = 48) evaluated, 88% of aneuploid primary lesions were associated with aneuploid metastases. Similarly, the distributions for MDR1, HER2, and p53 expression did not vary significantly between primary and metastatic sites. Pairings of metachronous cases (n = 66) revealed that nearly 80% of primary aneuploid tumors (n = 39) retained their aneuploid status at the time of relapse. Furthermore, there were no significant changes in MDR1, p53, or HER2 expression at relapse.

CONCLUSIONS

With the exception of EGF-R and CD31, clonal divergence of the biomarkers evaluated in this study probably does not play a significant role in imparting clinical heterogeneity during the advanced and recurrent stages of epithelial ovarian cancer. These particular genes likely undergo alterations early in the tumorigenesis process before metastases have become established.