Biomarker conservation in primary and metastatic epithelial ovarian cancer

Evolutionary dynamics of cancer multidrug resistance in response to olaparib and photodynamic therapy

P-glycoprotein (P-gp) is an adenosine triphosphate (ATP)-dependent drug efflux protein commonly associated with multidrug resistance in cancer chemotherapy. In this report, we used a dual-fluorescent co-culture model to study the population dynamics of the drug sensitive human ovarian cancer cell line (OVCAR-8-DsRed2) and its resistant subline that overexpresses P-gp (NCI/ADR-RES-EGFP) during the course of a photodynamic therapy (PDT)-olaparib combination regimen. Without treatment, OVCAR-8-DsRed2 cells grew more rapidly than the NCI/ADR-RES-EGFP cells. Olaparib treatment reduced the total number of cancer cells by 70±4% but selected for the resistant NCI/ADR-RES-EGFP population since olaparib is an efflux substrate for the P-gp pump. This study used the FDA-approved benzoporphyrin derivative (BPD) photosensitizer or its lipidated formulation ((16:0)LysoPC-BPD) to kill OVCAR-8 cells and reduce the likelihood that olaparib-resistant cells would have selective advantage. Three cycles of PDT effectively reduced the total cell number by 66±3%, while stabilizing the population ratio of sensitive and resistant cells at approximately 1:1. The combination of olaparib treatment and PDT enhanced PARP cleavage and deoxyribonucleic acid (DNA) damage, further decreasing the total cancer cell number down to 10±2%. We also showed that the combination of olaparib and (16:0)LysoPC-BPD-based PDT is up to 18-fold more effective in mitigating the selection of resistant NCI/ADR-RES-EGFP cells, compared to using olaparib and BPD-based PDT. These studies suggest that PDT may improve the effectiveness of olaparib, and the use of a lipidated photosensitizer formulation holds promise in overcoming cancer drug resistance.

Analytical validation of human epidermal growth factor receptor 2 immunohistochemistry by the use of the A0485 antibody versus the 4B5 antibody and breast versus gastric scoring guidelines in ovarian clear cell carcinoma

AIMS

The aim of this study was to evaluate human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) in ovarian clear cell carcinoma (OCCC) by using two antibodies and two scoring guidelines in correlation with HER2 amplification and clinicopathological features.

METHODS AND RESULTS

A tissue microarray was constructed by use of a total of 71 OCCC cases for IHC (the A0485 antibody and the 4B5 antibody) and dual-colour silver in-situ hybridisation (DISH). Two pathologists independently scored the IHC according to the 2018 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) breast cancer guidelines (breast guidelines) and the 2016 ASCO/CAP gastro-oesophageal adenocarcinoma guidelines (gastric guidelines). IHC concordances between A0485 and 4B5 were 87.3-93.0%. Three to 16 (4.2-22.5%) cases had an IHC score of 2+/3+ with frequent basolateral/lateral membranous staining. The 4B5 antibody yielded fewer IHC 2+ cases than the A0485 antibody (n = 2-6 versus n = 5-12). Five (7.0%) cases had HER2 amplification as determined with DISH. Cases with papillary-predominant growth patterns were significantly more likely to have HER2 amplification (P = 0.0051). In predicting DISH results, IHC scored according to the gastric guidelines yielded 100%/100% sensitivity and 83.3-95.5%/98.2-100% specificity, and IHC scored according to the breast guidelines yielded 60-80%/33.3-66.7% sensitivity and 95.5-100%/100% specificity (including/excluding IHC 2+ cases). One case had intratumoral heterogeneity, with discordant results between primary and metastatic tumour specimens.

CONCLUSION

We demonstrated HER2 amplification in 7% of OCCC cases, and the molecular change is significantly associated with papillary-predominant growth patterns. In predicting HER2 amplification, a combination of 4B5 IHC and gastric guidelines provides the best sensitivity and fewer equivocal (IHC 2+) cases. Given the intratumoral heterogeneity, assessment of HER2 status on whole tissue sections and on both primary and metastatic tumour specimens is recommended.

Cisplatin-loaded PLGA nanoparticles for HER2 targeted ovarian cancer therapy

The conventional treatment (cytoreduction combined with cisplatin/carboplatin and taxane drugs) of ovarian cancer has a high rate of failure and recurrence despite a favorable initial response. This lack of success is usually attributed to the development of multidrug resistance mechanisms by cancer cells and avoidance of the anti-growth effects of monoclonal targeted therapeutic antibodies. The disease, like other cancers, is characterized by the overexpression of molecular markers, including HER2 receptors. Preclinical and clinical studies with trastuzumab, a HER2-targeted therapeutic antibody, reveal a low improvement of the outcomes of HER2 positive ovarian cancer patients. Therefore, here, we propose a cisplatin-loaded, HER2 targeted poly(lactic-co-glycolic) nanoplatform, a system capable to escape the drug-efflux effect and to take advantage of the overexpressed HER2 receptors, using them as docks for targeted chemotherapy. The NP/trastuzumab ratio was determined after fluorescein labeling of antibodies and quantification of fluorescence in NPs. The system was also characterized in terms of size, zeta potential, drug release kinetics, cytotoxicity and cellular internalization in the epithelial ovarian cancer cell line SKOV-3, and compared with the HER2 negative breast cancer cell line HCC70. Our results show an increased cytotoxicity of NPs as compared to free cisplatin, and moreover, an enhanced internalization and cytotoxicity due to the bionfunctionalization of NPs with the monoclonal antibody.

Cell adhesion molecule profiles, proliferation activity and p53 expression in advanced epithelial ovarian cancer induced malignant ascites-Correlation of tissue microarray and cytology microarray

INTRODUCTION

Peritoneal dissemination accompanied by ascites formation is common in epithelial ovarian cancer (EOC). Adhesion molecules are crucial in metastatic spread and the latter involves epithelial-mesenchymal transition (EMT). This study aimed at: (1) clarifying whether E-cadherin and β-catenin expression and proliferative activity in metastatic ovarian cancer are inter-related; (2) Identifying possible correlations between cell adhesion molecular expression profiles, the proliferative activity and p53 expression of tumor cells and tumor grade and stage; (3) testing the cytology microarray (CMA) technique in analyzing metastasis formation.

MATERIAL AND METHODS

Both tumorous and ascitic samples from 27 EOC patients were examined by using tissue microarray (TMA) and cytology microarray (CMA), respectively. CMA blocks were constructed using cores from each cell block of the ascitic specimens. Expression of E-cadherin, β-catenin, Ki-67 and p53 was immunohistochemically detected both in TMA and CMA blocks.

RESULTS

E-cadherin expression was higher in ascitic cells than in primary tumor cells (p = .294). β-catenin expression was significantly lower in ascitic cells than in primary tumor cells (p = .006). Expression of Ki-67 was lower and expression of p53 was higher in primary tumors than in ascitic cells, for p53 the difference was significant (p = .001). Both Ki-67 and p53 expression elevated significantly in high-grade primary tumor cells and in ascites cells (p = .039, and p = .004, respectively).

CONCLUSION

Epithelial-mesenchymal transition- mesenchymal-epithelial transition is suggested as the best descriptive term for our IHC observations which accompany increased proliferative activity of ascitic cells. The CMA method is an adequate and reliable method for the analysis of ascitic tumor cells disseminating from ovarian malignancies.

The role of ABC transporters in ovarian cancer progression and chemoresistance

Over 80% of ovarian cancer patients develop chemoresistance which results in a lethal course of the disease. A well-established cause of chemoresistance involves the family of ATP-binding cassette transporters, or ABC transporters that transport a wide range of substrates including metabolic products, nutrients, lipids, and drugs across extra- and intra-cellular membranes. Expressions of various ABC transporters, shown to reduce the intracellular accumulation of chemotherapy drugs, are increased following chemotherapy and impact on ovarian cancer survival. Although clinical trials to date using ABC transporter inhibitors have been disappointing, ABC transporter inhibition remains an attractive potential adjuvant to chemotherapy. A greater understanding of their physiological functions and role in ovarian cancer chemoresistance will be important for the development of more effective targeted therapies. This article will review the role of the ABC transporter family in ovarian cancer progression and chemoresistance as well as the clinical attempts used to date to reverse chemoresistance.

In vitro chemoresponse in metachronous pairs of gyneclologic cancers

Background

While most gynecologic cancers respond to first-line cytotoxic chemotherapy, treatment of recurrent disease is frequently associated with acquired drug resistance. In order to find an in vitro surrogate of this clinical phenomenon, a tumor chemoresponse assay was studied.

Methods/Materials

Patients who had tissue submitted for repeated chemoresponse testing were identified through a retrospective search. Sixty-three patients met inclusion criteria (chemoresponse testing completed at primary diagnosis and upon recurrence of disease and assays completed ≥90 days apart). The Wilcoxon signed-rank test was used to compare chemoresponse, represented as a response index (RI), between primary and recurrent measurements. In a secondary analysis, response was categorized and coded as Responsive = 3, Intermediately Responsive = 2 and Non-Responsive = 1, and the paired t-test was used to compare chemoresponse between primary and recurrent measurement.

Results

Median time between primary and recurrent tumor testing was 309 days (IQR 208–422). Drugs tested included carboplatin, cisplatin, docetaxel, doxorubicin, gemcitabine, paclitaxel, topotecan, and combination carboplatin/gemcitabine and carboplatin/paclitaxel. There were no differences in chemoresponse between primary and recurrent measurement when chemoresponse was represented by RI scores; although a trend toward increased resistance to paclitaxel upon recurrence was noted. When chemoresponse was analyzed as a continuous variable corresponding to categorized response, a significant shift toward increased resistance to paclitaxel at recurrence, and a marginally significant trend toward increased resistance to carboplatin at recurrence, were observed.

Conclusions

We observed a trend toward increased chemoresistance at recurrence for paclitaxel, and a marginally significant trend toward increased chemoresistance to carboplatin, but no change in chemoresponsiveness between primary diagnosis and recurrence of disease for other common chemotherapy drugs, including common second-line agents such as doxorubicin, gemcitabine, and topotecan.

Potential use of humanized antibodies in the treatment of breast cancer

With the growing knowledge of key cellular pathways in tumor induction and evolution, targeted therapies make up an increasing proportion of new drugs entering clinical testing. In the treatment of breast cancer, humanized antibodies have become a major option. The humanized monoclonal antibody trastuzumab (Herceptin); Genentech, Inc., CA, USA) for HER2-overexpressing, metastatic breast cancer, represents a successful agent associated with impressive survival benefits when combined with chemotherapy. Based on impressive results, trastuzumab will become a standard in the adjuvant treatment of HER2-overexpressing breast cancer. The role of trastuzumab in the neoadjuvant setting is promising, but must be further evaluated in large prospective, randomized trials. However, there is still a large proportion of patients overexpressing HER2 that do not respond to trastuzumab. Regarding this patient cohort, the optimal combination of trastuzumab with other agents needs further evaluation. In breast cancer lacking HER2 amplification, the role of the new antibody pertuzumab remains to be defined. The role of antibodies interfering with angiogenesis, tumor stroma or glycoproteins is of a preliminary nature and warrants further investigation. Here, an overview of humanized antibodies in human breast cancer is provided, with emphasis on the recent advances and future prospects in treating malignant breast cancer.

HER2 expression beyond breast cancer: therapeutic implications for gynecologic malignancies

HER2 or ErbB2 is a member of the epidermal growth factor family and is overexpressed in subsets of breast, ovarian, gastric, colorectal, pancreatic, and endometrial cancers. HER2 regulates signaling through several pathways (Ras/Raf/mitogen-activated protein kinase and phosphatidylinositol-3 kinase/protein kinase B/mammalian target of rapamycin pathways) associated with cell survival and proliferation. HER2-overexpressed and/or gene-amplified tumors are generally regarded as biologically aggressive neoplasms. In breast, cervical, endometrial, and ovarian cancer, there have been several studies linking the amplification of the c-erbB2 gene with chemoresistance and overall poor survival. Tyrosine kinase inhibitors and immunotherapy with monoclonal antibodies targeting HER2 hold promise for patients harboring these aggressive neoplasms. Trastuzumab combined with cytotoxic chemotherapy agents or conjugated with radioactive isotopes is currently being investigated in clinical trials of several tumor types.

Therapeutic targeting of the phosphatidylinositol 3-kinase signaling pathway: novel targeted therapies and advances in the treatment of colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related death in the USA, and more effective treatment of CRC is therefore needed. Advances in our understanding of the molecular pathogenesis of this malignancy have led to the development of novel molecule-targeted therapies. Among the most recent classes of targeted therapies being developed are inhibitors targeting the phosphatidylinositol 3-kinase (PI3K) signaling pathway. As one of the most frequently deregulated pathways in several human cancers, including CRC, aberrant PI3K signaling plays an important role in the growth, survival, motility and metabolism of cancer cells. Targeting this pathway therefore has considerable potential to lead to novel and more effective treatments for CRC. Preclinical and early clinical studies have revealed the potential efficacy of drugs that target PI3K signaling for the treatment of CRC. However, a major challenge that remains is to study these agents in phase III clinical trials to see whether these early successes translate into better patient outcomes. In this review we focus on providing an up-to-date assessment of our current understanding of PI3K signaling biology and its deregulation in the molecular pathogenesis of CRC. Advances in available agents and challenges in targeting the PI3K signaling pathway in CRC treatment will be discussed and placed in the context of the currently available therapies for CRC.

Prognostic value of human epidermal growth factor receptor 2 (Her-2)/neu in patients with advanced ovarian cancer treated with platinum/paclitaxel as first-line chemotherapy: a retrospective evaluation of the AGO-OVAR 3 Trial by the AGO OVAR Germany

OBJECTIVES

Results on the prognostic value of human epidermal growth factor receptor 2 (HER-2)/neu in ovarian cancer are inconsistent. This exploratory analysis evaluates Her-2/neu as a prognostic factor in a large cohort of patients with advanced-stage ovarian cancer treated with platinum/paclitaxel as first-line chemotherapy within a prospective randomized trial.

METHODS

Her-2/neu expression was assessed by immunohistochemistry in 359 patients (46%) treated within the AGO-OVAR 3 trial (n = 783). Patients received either cisplatin/paclitaxel or carboplatin/paclitaxel according to the study protocol. Immunohistochemistry results were scored according to the Dako score.

RESULTS

Her-2/neu Dako scores of 0 or 1+ was found in 337 patients (94%) and a score of 2+ or 3+ in 22 patients (6%). Her-2/neu overexpression (2+/3+) was associated with a higher International Federation of Gynecology and Obstetrics stage and larger postoperative residual disease. There were no significant differences in response to chemotherapy between the Her-2/neu score subgroups and in progression-free survival time. In a multivariate analysis, the Her-2/neu score had no significant impact on overall survival time.

CONCLUSIONS

In the present study, Her-2/neu overexpression in patients with advanced-stage ovarian cancer was rare and provided no evidence for a prognostic value of Her-2/neu in patients with advanced ovarian cancer treated with platinum/paclitaxel.

Ovarian carcinoma cells in effusions show increased S-phase fraction compared to corresponding primary tumors

The objective of this study was to analyze large-scale genomic patterns during disease progression from primary tumor to effusion in ovarian carcinoma, and to study the association between DNA ploidy parameters in effusions, proliferation/survival markers, and clinicopathologic characteristics. DNA ploidy status, DNA index (DI), and S-phase fraction (SPF) were compared in 22 matched primary carcinomas (all prechemotherapy specimens) and effusions (14 prechemotherapy and 8 postchemotherapy specimens) using image analysis. The association between these parameters and previously studied cell survival/proliferation biomarkers, previous administration of chemotherapy, chemotherapy response and survival was analyzed in a larger series of 54 effusions. The majority of specimens were aneuploid irrespective of anatomic site, with no significant differences in DI. SPF was significantly higher in effusions compared to matched primary tumors (P = 0.007 for all 22 pairs, P = 0.011 for 14 matched prechemotherapy specimens). Higher SPF was related to higher Ki-67 score (P = 0.045), and both SPF and DI were directly associated with higher level of Survivin (P < 0.001 for both). DI and SPF in effusions showed no association with histological grade, FIGO stage, residual disease volume, previous chemotherapy, response to chemotherapy at primary disease, recurrence or survival. Ovarian carcinoma cells in effusions have increased proliferation compared to corresponding primary tumors, as evidence of disease progression. DNA ploidy parameters in cancer cells in effusions are unaltered by chemotherapy and appear to be unrelated to chemotherapy response and to survival, suggesting that large-scale genomic patterns at this anatomic site are not useful in segregating patients into prognostic groups.

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.

[177Lu]pertuzumab: experimental therapy of HER-2-expressing xenografts

Pertuzumab (Omnitarg) is a novel antibody against HER-2, domain II. HER-2 is a tyrosine kinase receptor that is overexpressed in several carcinomas, especially breast cancer. Pertuzumab, labeled with the low-energy beta emitter (177)Lu, might be a candidate for targeted radiotherapy of disseminated HER-2-positive micrometastases. The radiolabeled antibody [(177)Lu]pertuzumab showed favorable targeting properties in BALB/c (nu/nu) mice with HER-2-overexpressing xenografts. The absorbed dose in tumors was more than five times higher than the absorbed dose in blood and more than seven times the absorbed dose in any other normal organ. Experimental therapy showed that [(177)Lu]pertuzumab delayed tumor progression compared with controls (no treatment, P < 0.0001; nonlabeled pertuzumab antibody, P < 0.0001; and (177)Lu-labeled irrelevant antibody, P < 0.01). No adverse side effects of the treatment could be detected. Thus, the experimental results support the planning of clinical studies applying [(177)Lu]pertuzumab for therapy.

Selective proapoptotic activity of a secreted recombinant antibody/AIF fusion protein in carcinomas overexpressing HER2

Apoptosis-inducing factor (AIF) represents a caspase-independent apoptotic pathway in the cell, and a mitochondrial localization sequence-truncated AIF (AIFDelta1-120) can be relocated from the cytoplasm to the nucleus and exhibit a constitutive proapoptotic activity. Here, we generated a chimeric immuno-AIF protein, which comprised an HER2 antibody, a Pseudomonas exotoxin translocation domain and AIFDelta1-120. Human Jurkat cells transfected with the immuno-AIF gene could express and secrete the chimeric protein, which selectively recognized HER2-overexpressing tumor cells and was endocytosed. Subsequent cleavage of truncated AIF from immuno-AIF and its release from the internalized vesicles resulted in apoptosis of tumor cells. Intramuscular injection of the immuno-AIF gene caused significant suppression of tumors and substantially prolonged mice survival in an HER2-overexpressing xenograft tumor model. Our study demonstrates the feasibility of the immuno-AIF gene as a novel approach to treating cancers that overexpress HER2.

Conservation of in vitro drug resistance patterns in epithelial ovarian carcinoma

PURPOSE

To compare the in vitro drug resistance profiles of advanced stage primary and recurrent epithelial ovarian cancer specimens using the tritiated thymidine uptake assay.

METHODS

Extreme drug resistance (EDR) to cisplatin, paclitaxel, 4-hydroxycyclophosphamide, and topotecan was determined for an unselected population of primary and metastatic malignant ovarian tissues, synchronous tumors (primary and metastatic tissues obtained from the same patient at diagnosis), and metachronous lesions (specimens from the same patient before and after chemotherapy).

RESULTS

For the large unselected population of malignant tissues (total, N = 6990; primary ovarian, N = 2031; metastatic ovarian, N = 4959), no statistically significant differences were discovered between primary tissues and metastatic lesions when a comparison was made between the percentage of tumors from each group that exhibited extreme drug resistance to the agents assayed. From the library of 6990 specimens, 119 synchronous pairings were identified. These synchronous lesions did not differ significantly in the %EDR between primary and metastatic sites in the same patient; approximately 10% shifted between low drug resistance and EDR. A total of 334 metachronous pairings were identified and the percentage of tissues that exhibited EDR also failed to show a significant difference when primary tumors were compared with matched recurrences in the same patient.

CONCLUSIONS

For the agents studied, acquired resistance was not a function of disease site. In vitro drug resistance observed at recurrence was not influenced significantly by intervening therapy. It is possible that assay results at diagnosis could be used to guide subsequent therapy at relapse, especially when recurrent tissue is not available for analysis.

[177Lu]pertuzumab: experimental studies on targeting of HER-2 positive tumour cells

PURPOSE

The new antibody pertuzumab (Omnitarg) targets the dimerisation subdomain of HER-2. The purpose of this study was to analyse whether pertuzumab retains HER-2 targeting capacity after labelling with the therapeutically interesting beta emitter (177)Lu and to make initial characterizations in vitro and in vivo.

METHODS

Pertuzumab was conjugated with isothiocyanate-benzyl-CHX-A''-DTPA and chelated to (177)Lu. Immunoreactivity, affinity, cellular retention and internalisation were analysed using SKOV-3 cells. The affinity of non-radioactive pertuzumab was measured using a surface plasmon resonance biosensor. In vivo targeting and specific binding were assessed in Balb/c (nu/nu) mice carrying SKOV-3 xenografts. The biodistribution of (177)Lu was determined 1, 3 and 7 days after [(177)Lu]pertuzumab administration. Gamma camera images were taken after 3 days.

RESULTS

The immunoreactivity of [(177)Lu]pertuzumab was 85.8+/-1.3%. The affinity of non-radioactive pertuzumab was 1.8+/-1.1 nM, and that of [(177)Lu]pertuzumab, 4.1+/-0.7 nM. The cellular retention after 5 h pre-incubation was 90+/-2% at 20 h. The targeting was HER-2 specific both in vitro and in vivo, since excess amounts of non-labelled antibody inhibited the uptake of labelled antibody (p<0.0001 and p<0.01, respectively). The biodistribution and gamma camera images of (177)Lu showed extensive tumour uptake. Normal tissues had a surprisingly low uptake.

CONCLUSION

Pertuzumab was efficiently labelled with (177)Lu and showed good intracellular retention and HER-2 specific binding both in vitro and in vivo. The gamma camera images and the biodistribution study gave excellent tumour targeting results. Thus, [(177)Lu]pertuzumab is of interest for further studies aimed at radionuclide therapy.

Prognostic significance of p53, Her-2, and EGFR overexpression in borderline and epithelial ovarian cancer

The objective of the study was to evaluate the prognostic effect of p53, Her-2, and EGFR in borderline and epithelial ovarian cancer. Tumor tissue from 85 patients with borderline and 783 patients with epithelial ovarian cancer stage I-IV were analyzed immunohistochemically for p53 positivity and over-expression of Her-2 and EGFR. In the ovarian cancer (OC) group 415 patients (53%) had p53-positive tumors, 272 (35%) had tumors with Her-2 over-expression, and 483 (62%) had over-expression of EGFR. In the OC group the classical prognostic factors (older age, higher FIGO stage, and poorer differentiated stage) had significant prognostic value in both uni- and multivariate analyses. Multivariate analyses in the OC group proved p53 positivity to increase mortality significantly depending on the grade of the tumor. Her-2 likewise increased the risk of mortality significantly in this group depending on the grade of the tumor. EGFR on the other hand did not have any additional prognostic effect in the OC group after adjustment for the classical prognostic and molecular factors was made. In the borderline group Her-2 and EGFR over-expression in combination, adjusted for age and p53, significantly improved the prognosis.

[The pathologist and EGFR in 2004: I like you, nor do it]

Epithelial growth factor receptor (EGFR) appears as a key element in carcinogenesis. It displays high levels of expression in some tumor types. Its activation induces cell proliferation, angiogenesis, cell mobility and inhibition of apoptosis. EGFR inhibitors such as monoclonal antibodies or small molecules tyrosine kinase inhibitors have been developed. For EGFR, the diversity of the activation means (amplification, mutation, enhanced transcription, ligands...) leads to technical caveats. Immunohistochemistry appears to be the most appropriate test for clinical use, but standardized assays and scoring systems are mandatory. Pathologists are involved in the selection of patients for a monoclonal antibody based targeted treatment, Erbitux, and numerous standardization efforts are provided. No consensus has been reached, to date, for a scoring system. Whether the EGFR status has to be tested for the selection of patients is a non answered question. The selection of the "right patient for the right treatment" might be through the evaluation of other putative markers involved in resistance. EGFR testing may be required before targeted treatment. An exciting endpoint might be the functional and dynamic evaluation of EGFR and downstream proteins, for patients, before and during treatment. The exact role of the pathologist still have to be accurately determined.

Phenotypic variation resulting from a deficiency of epidermal growth factor receptor in mice is caused by extensive genetic heterogeneity that can be genetically and molecularly partitioned

The timing of lethality caused by homozygosity for a null allele of the epidermal growth factor receptor (Egfrtm1Mag) in mice is strongly dependent on genetic background. Initial attempts to genetically map background modifiers using Swiss-derived, outbred CD-1 mice were unsuccessful. To investigate the genetic architecture contributing to survival of Egfrtm1Mag homozygous embryos, the genetic variability segregating within the outbred population was partitioned by surveying viability of Egfrtm1Mag mutants using intercrosses between 129S6/SvEvTAC-Egfrtm1Mag and nine Swiss-derived, inbred strains: ALR/LtJ, ALS/LtJ, APN, APS, ICR/HaRos, NOD/LtJ, NON/LtJ, SJL/J, and SWR/J. The observations showed that these strains support varying levels of survival of Egfrtm1Mag homozygous embryos, suggesting that genetic heterogeneity within the CD-1 stock contributed to the original lack of Egfrtm1Mag modifier detection. Similar to the Swiss-derived intercrosses, nine congenic strains, derived from 129S6/SvEvTAC, AKR/J, APN, BALB/cJ, BTBR-T+ tf/tf, C3H/HeJ, C57BL/6J, DBA/2J, and FVB/NJ inbred backgrounds, also supported varying levels of survival of Egfrtm1Mag mutants. By intercrossing the congenic lines to create hybrid F1 embryos, different genetic backgrounds were found to have complementary modifiers. Analysis of the congenic lines argues against heterosis of outbred backgrounds contributing to Egfrtm1Mag phenotypic variability. A detailed analysis of the crosses suggests that modifiers function at three distinct stages of development. One class of modifiers supports survival of Egfrtm1Mag homozygous embryos to mid-gestation, another class supports development through the mid-gestation transition from yolk-sac to placental-derived nutrient sources, and a third class supports survival through later stages of gestation. Data from microarray analysis using RNA from wild-type and Egfrtm1Mag mutant placentas support the existence of extensive genetic heterogeneity and suggest that it can be molecularly partitioned. This method should be generally useful to partition heterogeneity contributing to other complex traits.

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.

HER2 expression in breast cancer primary tumours and corresponding metastases. Original data and literature review

The aim of this study was to evaluate whether the HER2 expression in breast cancer is retained in metastases. The HER2 expression in primary tumours and the corresponding lymph node metastases were evaluated in parallel samples from 47 patients. The HercepTest was used for immunohistochemical analyses of HER2 overexpression in all cases. CISH/FISH was used for analysis of gene amplification in some cases. HER2 overexpression (HER2-scores 2+ or 3+) was found in 55% of both the primary tumours and of the lymph node metastases. There were only small changes in the HER2-scores; six from 1+ to 0 and one from 3+ to 2+ when the metastases were compared to the corresponding primary tumours. However, there were no cases with drastic changes in HER2 expression between the primary tumours and the corresponding lymph node metastases. The literature was reviewed for similar investigations, and it is concluded that breast cancer lymph node metastases generally overexpress HER2 to the same extent as the corresponding primary tumours. This also seems to be the case when distant metastases are considered. It has been noted that not all patients with HER2 overexpression respond to HER2-targeted Trastuzumab treatment. The stability in HER2 expression is encouraging for efforts to develop complementary forms of therapy, for example, therapy with radionuclide-labelled Trastuzumab.

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.

Nicotine promoted colon cancer growth via epidermal growth factor receptor, c-Src, and 5-lipoxygenase-mediated signal pathway

Nicotine [3-(1-methyl-2-pyrrolidinyl)-pyridine], a major alkaloid in tobacco, has been implicated as playing a role in carcinogenesis. Our previous study showed that passive cigarette smoking promoted inflammation-associated colonic adenoma formation in mice, and 5-lipoxygenase (5-LOX) plays an important role in this process. In the present study, we aimed to investigate whether nicotine could stimulate colon cancer cell proliferation and tumor growth in nude mice xenograft model and the possible mechanisms involved. Results showed that nicotine stimulated SW1116 colon cancer cell proliferation in a dose-dependent manner. Epidermal growth factor receptor (EGFR) and c-Src phosphorylation levels together with protein expression of 5-LOX were also significantly enhanced in this proliferation process. Inhibitors of EGFR and c-Src alleviated the actions of nicotine on cell proliferation and 5-LOX protein expression. Combination of both agents produced additive effect. In contrast, 5-LOX inhibitor had no direct effect on the phosphorylation levels of EGFR and c-Src and yet inhibited cell proliferation. In the colon cancer xenograft model, nicotine also significantly enhanced tumor growth. This acceleration of tumor growth corresponded well with increased vascularization and its proangiogenic factors. Inhibitors of EGFR, c-Src, and 5-LOX all significantly impeded the tumor growth induced by nicotine. Together, nicotine can promote colonic tumorigenesis both in vitro and in vivo. Activation of the phosphorylated form of EGFR and c-Src followed by an increased 5-LOX expression are the prime pathogenic mechanisms in the tumorigenic process in the colon.

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.

Ligand liposomes and boron neutron capture therapy

Boron neutron capture therapy (BNCT) has been used both experimentally and clinically for the treatment of gliomas and melanomas, with varying results. However, the therapeutic effects on micro-invasive tumor cells are not clear. The two drugs that have been used clinically, p-boronophenylalanine, (BPA), and the sulfhydryl borane, (BSH), seem to be taken up preferentially in solid tumor areas but it is uncertain whether enough boron is taken up by micro-invasive tumor cells. To increase the selective uptake of boron by such cells, would be to exploit tumor transformation related cellular changes such as over-expression of growth factor receptors. However, the number of receptors varies from small to large and the uptake of large amounts of boron for each receptor interaction is necessary in order to deliver sufficient amounts of boron. Therefore, each targeting moiety must deliver large number of boron atoms. One possible way to meet these requirements would be to use receptor-targeting ligand liposomes, containing large number of boron atoms. This will be the subject of this review and studies of boron containing liposomes, with or without ligand, will be discussed. Two recent examples from the literature are ligand liposomes targeting either folate or epidermal growth factor (EGF) receptors on tumor cells. Other potential receptors on gliomas include PDGFR and EGFRvIII. Besides the appropriate choice of target receptor, it is also important to consider delivery of the ligand liposomes, their pharmacodynamics and pharmacokinetics and cellular processing, subjects that also will be discussed in this review.

Tumour therapy with radionuclides: assessment of progress and problems

Radionuclide therapy is a promising modality for treatment of tumours of haematopoietic origin while the success for treatment of solid tumours so far has been limited. The authors consider radionuclide therapy mainly as a method to eradicate disseminated tumour cells and small metastases while bulky tumours and large metastases have to be treated surgically or by external radiation therapy. The promising therapeutic results for haematological tumours give hope that radionuclide therapy will have a breakthrough also for treatment of disseminated cells from solid tumours. New knowledge related to this is continuously emerging since new molecular target structures are being characterised and the knowledge on pharmacokinetics and cellular processing of different types of targeting agents increases. There is also improved understanding of the factors of importance for the choice of appropriate radionuclides with respect to their decay properties and the therapeutic applications. Furthermore, new methods to modify the uptake of radionuclides in tumour cells and normal tissues are emerging. However, we still need improvements regarding dosimetry and treatment planning as well as an increased knowledge about the tolerance doses for normal tissues and the radiobiological effects on tumour cells. This is especially important in targeted radionuclide therapy where the dose rates often are lower than 1Gy/h.

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.

The prognostic importance of p53, bcl-2, and bax in early stage epithelial ovarian carcinoma treated with adjuvant chemotherapy

Epithelial ovarian cancer is one of the major causes of death among women. The increasing knowledge about molecular events involved in the early stages of ovarian tumorigenesis may provide the basis for management in the future. In a series of 109 patients with epithelial carcinomas in FIGO stages IA-IIC, a number of clinicopathologic prognostic factors (age, FIGO stage, histopathologic type, and tumor grade) were studied in relation to the biologic factors p53, bcl-2, and bax, which are important regulators of apoptosis. Immunohistochemical techniques were used. All the patients received adjuvant chemotherapy after the primary surgery. Univariate analysis showed that expression of p53 was significantly associated with tumor grade (P = 0.014), probability of persistent disease (P = 0.016), and cancer-specific survival rate (P = 0.007). Positive bcl-2 staining was associated with endometrioid tumor subtype (P = 0.029) and a favorable tumor grade distribution (P = 0.034), but not with the survival status. The combined p53-bcl-2 expression was related to histopathologic subtype (P = 0.032), tumor grade (P = 0.011), persistent disease (P = 0.014), and risk of dying due to the disease (P = 0.039). The bax status was not a prognostic factor, but the combined p53-bax expression showed an association with FIGO stage (P = 0.014), tumor grade (P = 0.034), persistent disease (P = 0.006), and risk of dying due to the disease (P = 0.039). The combined bcl-2-bax expression was related to histopathologic subtype (P = 0.045) and tumor grade (P = 0.022). In a multivariate Cox analysis, tumor grade (P = 0.014), and p53 status (P = 0.020) were independent and significant prognostic factors with regard to the cancer-specific survival rate.

Importance of epidermal growth factor receptor signaling in establishment of adenomas and maintenance of carcinomas during intestinal tumorigenesis

We used the hypomorphic Egfr(wa2) allele to genetically examine the impact of impaired epidermal growth factor receptor (Egfr) signaling on the Apc(Min) mouse model of familial adenomatous polyposis. Transfer of the Apc(Min) allele onto a homozygous Egfr(wa2) background results in a 90% reduction in intestinal polyp number relative to Apc(Min) mice carrying a wild-type Egfr allele. This Egfr effect is potentially synergistic with the actions of the modifier-of-min (Mom1) locus. Surprisingly, the size, expansion, and pathological progression of the polyps appear Egfr-independent. Histological examination of the ilea of younger animals revealed no differences in the number of microadenomas, the presumptive precursor lesions to gross intestinal polyps. Pharmacological inhibition with EKI-785, an Egfr tyrosine kinase inhibitor, produced similar results in the Apc(Min) model. These data suggest that normal Egfr activity is required for establishment of intestinal tumors in the Apc(Min) model between initiation and subsequent expansion of initiated tumors. The role of Egfr signaling during later stages of tumorigenesis was examined by using nude mice xenografts of two human colorectal cancer cell lines. Treatment with EKI-785 produced a dose-dependent reduction in tumor growth, suggesting that Egfr inhibitors may be useful for advanced colorectal cancer treatment.

Papillary serous carcinoma of the peritoneum coexisting with or after endometrial carcinoma

OBJECTIVE

Papillary serous carcinoma of the peritoneum (PSCP) coexisting with, or after, endometrial carcinoma (EC) is an extremely rare condition with no documented patient series. The aim of this investigation was to describe our experience in treating five patients diagnosed with PSCP synchronously with EC and two others who developed PSCP metachronously after EC.

METHODS

In this retrospective study, we reviewed and analyzed the clinical and pathological data of seven patients diagnosed and managed over a 10-year period. The diagnosis of PSCP was mostly based on the inclusionary criteria of the Gynecologic Oncology Group [1]. Disease stages were determined using the FIGO criteria for epithelial ovarian cancer (EOC) and endometrial carcinomas [2]. The treatment for PSCP was similar to that for advanced EOC and immunohistochemical studies were performed using archival material for PSCP and EC in order to determine p53, Bcl-2, HER2, and estrogen and progesterone receptor (ER, PR) status. Germline mutation analyses were performed for the two most common mutations pertaining to BRCA1 and the one most common mutation pertaining to BRCA2 genes only.

RESULTS

Five patients with PSCP and synchronous EC initially underwent surgical treatment. The remaining two underwent surgery originally for EC and, thereafter, for metachronous PSCP. All seven patients had advanced stages (III or IV) of PSCP and stage I only EC. At the time of analysis, four patients were alive. p53, Bcl-2, ER, and PR were found to have been expressed in various rates in both or one of the neoplasms. However, no HER2 was found to have been expressed, either in PSCP or in EC. All germline mutation analyses were negative.

CONCLUSIONS

The results obtained in this study show that PSCP can occur either synchronously or metachronously with lower stage EC that is associated with advanced disease stages. We suggest that this clinical form of PSCP with synchronous or metachronous EC is a very aggressive and lethal clinical form and differs markedly from the vast majority of multiple gynecologic neoplasms of the upper genital canal diagnosed in the ovarian-endometrial group, of which EOC are mostly diagnosed as stage I diseases with high-rate cures.