Higher frequency of chromosomal aberrations in ovarian endometriosis compared to extragonadal endometriosis: A possible link to endometrioid adenocarcinoma

Factors in malignant transformation of ovarian endometriosis: A narrative review

Endometriosis is a common estrogen-dependent inflammatory disease with a chronic course and a tendency to recur. The association between endometriosis and cancer has been studied for several years. Numerous reports have demonstrated a strong association between specific ovarian malignancies and endometriotic lesions. Atypical endometriosis has been widely described as a malignant precursor to ovarian epithelial tumors, particularly clear cell carcinomas and endometrioid carcinomas. These histological types associated with endometriosis develop predominantly in the ovary rather than in extragonadal sites. The detailed molecular mechanism of etiology remains unclear. Recent studies have analyzed the genetic and molecular mechanisms involved in endometriosis-associated ovarian cancer. A critical role appears to be played by a carcinogenic model based on iron-induced oxidative stress, which is typical of the endometriosis microenvironment. It has been hypothesized that trans-tubal reflux of blood, endometrial cells and associated iron-induced oxidative stress underlie the development of endometriosis-associated ovarian cancer. However, the multifactorial mechanisms of this malignant transformation are not fully understood. The aim of this review is to summaries the current epidemiological, histopathological, genetic and molecular findings in the progression of endometriosis-associated ovarian cancer.

Endometriosis-Associated Ovarian Cancer: From Molecular Pathologies to Clinical Relevance

Endometriosis is a chronic condition affecting reproductive-aged women, characterized by the growth of ectopic endometrial tissue. Despite being benign, endometriosis is associated with an increased risk of certain cancers, including endometriosis-associated ovarian cancer (EAOC). Ovarian cancer is rare, but more common in women with endometriosis, particularly endometrioid and clear-cell carcinomas. Factors such as hormonal imbalance, reproductive history, environmental exposures, and genetic predisposition contribute to the malignant transformation of endometriosis. Thus, understanding potential risk factors causing malignancy is crucial. Over the past few decades, various genetic mutations, microRNAs, as well as tumor microenvironmental factors have been identified, impacting pathways like PI3K/AKT/mTOR, DNA repair mechanisms, oxidative stress, and inflammation. Thus, this review aims to summarize molecular studies involved in EAOC pathogenesis as potential therapeutic targets. However, further research is needed to better understand the molecular and environmental factors driving EAOC development, to target the susceptibility of endometriotic lesions to malignant progression, and to identify effective therapeutic strategies.

Predictive factors of endometriosis progression into ovarian cancer

BACKGROUND

In recent years, the endometriosis has overcome a noteworthy renaissance in the recognition of its potential. In certain patients, a demonstrable malignant progression of ectopic foci leading to development of ovarian cancer is seen. The knowledge of endometriosis overthrow background into endometriosis associated ovarian cancer is of paramount importance for selection of patients at risk. The goal of the presented study was to review a malignant potential of the endometriosis and to specify predictive factors of endometriosis progression into ovarian cancer. Altogether 189 patients were included in the study. Conventional cytogenetics as well as measurement of transcriptional activity of CTNNB1 (β-catenin) and HIF1A (HIF1-α) genes were prospectively studied in 60 endometriosis patients and 50 control group patients. The retrospective histopathological analysis was performed in 19 endometriosis associated ovarian cancer patients and 60 patients with histologically confirmed endometriosis.

RESULTS

Five endometriosis patients showed a deviation from normal cytogenetics finding without affecting of their phenotype. In 6 cases of endometriosis associated ovarian cancer ectopic endometrium was not confirmed. The remaining 13 cases demonstrated either benign or atypical endometriosis or even structures of borderline carcinoma. Atypical endometriosis was histologically confirmed in 20% of 60 endometriosis patients. Determination of gene expression (CTNNB1, HIF1A) formed two subgroups. Transcriptionally incipient endometriosis subgroup with insignificant genes expression compared to control group. In transcriptionally evident endometriosis subgroup were genes expressions significantly higher compared to control group (p < 0.01) as well as transcriptionally incipient endometriosis subgroup (p < 0.05).

CONCLUSIONS

Significant structural abnormalities of chromosomes are not included in genetic rigging of endometriosis patients. Atypical endometriosis represents a histopathologically detectable intermediate of endometriosis progression. Determination of genes expression CTNNB1 and HIF1A helps to allocate risk patients with endometriosis where more precise management is needed.

Cytogenetic findings of ectopic endometriotic tissue in women with endometriosis and review of the literature

OBJECTIVE

To determine chromosome and gene alterations in ectopic endometrial (EM) tissue which may be implicated in the clinical course or the progression of endometriosis and to review the literature concerning the cytogenetic findings of women with endometriosis.

STUDY DESIGN

15 women who underwent laparoscopic endometriosis surgery at the Athens Genesis Clinic were enrolled in the study. Ectopic endometrial tissue was surgically removed and further analyzed by conventional and molecular cytogenetic techniques. Fluoresent in situ hibridization (FISH) with probes for p53, ATM, MYC, MLL1 and IGH genes, the centromeres of chromosomes 7 and 8 and 7q22/7q31 chromosomal regions was carried out.

RESULTS

Karyotypic analysis revealed no clonal chromosomal abnormalities. However, an increased frequency of polyploidy (55.6%) and sporadic chromosomal abnormalities (40.0%) concerning chromosomes 9, 11, 17 and X were noticed involving mainly deletions, trisomies or monosomies. FISH analysis showed IGH gene rearrangements in 54% of the EM cases and MLL gene rearrangements in 73% of the examined samples. Normal hybridization patterns were observed for p53, ATM and MYC. The increased frequency of polyploidy shown by conventional karyotyping was also confirmed by FISH.

CONCLUSION

Polyploidy, sporadic chromosomal abnormalities, as well as IGH and MLL gene rearrangements, may provoke genetic instability and play a potential role in the development of endometriosis. IGH and MLL gene rearrangements indicate a genetic relation between endometriosis and carcinogenesis. Confirmation of the above gene rearrangements in a large series of women may allow the determination of their possible involvement in the pathogenesis of this complex disease and their possible contribution in the early identification of women in danger for malignant transformation.

Somatic Genomic Events in Endometriosis: Review of the Literature and Approach to Phenotyping

In this review, we provide a survey and appraisal of research into somatic genomic events in endometriosis. Methodologies have evolved from conventional cytogenetics to next-generation sequencing, with findings ranging from chromosome imbalances to recurrent somatic cancer driver mutations. Somatic cancer driver mutations have been described in a range of endometriosis lesions, dominated by recurrent mutations in KRAS and PIK3CA as well as loss of PTEN and BAF250a (ARID1A). These somatic events appear to be largely restricted to the endometriosis glandular epithelium. Somatic mutations, particularly PTEN loss, have also been observed in eutopic (uterine) endometrium, although at lower mutant allele frequencies compared with ectopic lesions. Systematic studies of the potential clinical phenotype of these somatic genomic events have yet to be performed. Thus, we propose a framework to investigate the potential clinical phenotype associated with somatic genomic events in endometriosis. Technical requirements include pathology review of histological endometriosis, microdissection for tissue enrichment, orthogonal validation of whole genome/exome sequencing, and a germline sample for confirmation of somatic origin. Clinical requirements include annotation of surgical findings; patient demographics; cross-sectional and prospective data on pain and fertility; consideration of sampling multiple lesions in each patient, mutant allele frequency, and somatic events in the eutopic endometrium; and confirmation of any associations with mechanistic studies. Given the multifactorial nature of endometriosis-associated symptoms, it is likely that somatic events have small (or at most, moderate) effect sizes, and thus careful consideration will have to be given to future study design.

Establishment of an Immortalized Endometriotic Stromal Cell Line from Human Ovarian Endometrioma

Endometrial-like stromal cells, one of the main components of endometriotic lesions, are an important in vitro model for studying cellular and molecular mechanisms associated with lesion development in endometriosis. However, the short life span of primary endometriotic stromal cells (Ec-ESCs) limits their use. Human telomerase reverse transcriptase (hTERT) plasmids can be used to develop immortalized cell lines. Here we aimed to establish an endometriotic stromal cell line by hTERT immortalization. Primary Ec-ESCs were obtained from a human ovarian endometriotic cyst. The purity was assessed by morphology and the expression of vimentin, cytokeratin, and human interferon-inducible transmembrane protein 1 (hIFITM1). Cells were infected with hTERT lentiviral vector and selected with hygromycin. hTERT mRNA levels were confirmed by RT-qPCR. Immortalized Ec-ESCs (iEc-ESCs) were characterized by examining the expression of morphological markers and key genes of interest, TP53, estrogen receptor β (ERβ), progesterone receptor (PR), and steroidogenic factor-1 (SF-1). Karyotyping and in vitro decidualization studies were also performed. Ec-ESCs were positive for vimentin and hIFITM1 and negative for cytokeratin, indicating that they were representative of Ec-ESC. The fibroblast-like morphology, expression of TP53, ERβ, PR, and SF-1 did not change before and after hTERT immortalization. iEc-ESCs showed an impaired decidualization response like primary Ec-ESCs when compared to normal eutopic stromal cells. Karyotyping showed that 15/19 cells had normal female karyotype, while 4/19 cells had partial trisomy 11q. Collectively, we successfully established and characterized an immortalized endometriotic stromal cell line. It is potentially useful as an in vitro experimental model to investigate endometriosis biology.

Interplay Between MicroRNAs and Oxidative Stress in Ovarian Conditions with a Focus on Ovarian Cancer and Endometriosis

Ovarian cancer and endometriosis are two distinct gynaecological conditions that share many biological aspects incuding proliferation, invasion of surrounding tissue, inflammation, inhibition of apoptosis, deregulation of angiogenesis and the ability to spread at a distance. miRNAs are small non-coding RNAs (19–22 nt) that act as post-transcriptional modulators of gene expression and are involved in several of the aforementioned processes. In addition, a growing body of evidence supports the contribution of oxidative stress (OS) to these gynaecological diseases: increased peritoneal OS due to the decomposition of retrograde menstruation blood facilitates both endometriotic lesion development and fallopian tube malignant transformation leading to high-grade serous ovarian cancer (HGSOC). Furthermore, as HGSOC develops, increased OS levels are associated with chemoresistance. Finally, continued bleeding within ovarian endometrioma raises OS levels and contributes to the development of endometriosis-associated ovarian cancer (EAOC). Therefore, this review aims to address the need for a better understanding of the dialogue between miRNAs and oxidative stress in the pathophysiology of ovarian conditions: endometriosis, EAOC and HGSOC.

Origins based clinical and molecular complexities of epithelial ovarian cancer

Ovarian cancer is the most lethal of all common gynaecological malignancies in women worldwide. Ovarian cancer comprises of >15 distinct tumor types and subtypes characterized by histopathological features, environmental and genetic risk factors, precursor lesions and molecular events during oncogenesis. Recent studies on gene signature profiling of different subtypes of ovarian cancer have revealed significant genetic heterogeneity between and within each ovarian cancer histological subtype. Thus, an immense interest have shown towards a more personalized medicine for understanding the clinical and molecular complexities of four major types of epithelial ovarian cancer (serous, endometrioid, clear cell, and mucinous). As such, further in depth studies are needed for identification of molecular signalling network complexities associated with effective prognostication and targeted therapies to prevent or treat metastasis. Therefore, understanding the metastatic potential of primary ovarian cancer and therapeutic interventions against lethal ovarian cancer for the development of personalized therapies is very much indispensable. Consequently, in this review we have updated the key dysregulated genes of four major subtypes of epithelial carcinomas. We have also highlighted the recent advances and current challenges in unravelling the complexities of the origin of tumor as well as genetic heterogeneity of ovarian cancer.

Recent Advances in Molecular Genetics of Endometriosis

Endometriosis (MIM 131200) is a prevalent and complex gynecological disease polygenically inherited with multifactorial pathogenesis. It is increasingly recognized as a major women's health issue. Endometriosis is characterized by the presence of endometrial-like tissue in sites outside the uterus, mainly the pelvic peritoneum, ovaries and rectovaginal septum causing severe dysmenorrhoea, dyspareunia, chronic pelvic pain and subfertility. Recent advances in molecular technologies have provided many evidences about the underlying biological events that are likely to be involved in the development of endometriosis. Different chromosomal regions, genes and other molecules, such as microRNAs, have been identified as potentially involved in endometriosis pathogenesis. Moreover, genome-wide analyses of endometriosis have showed novel molecular signatures or individual genes that had not been previously associated with the disease. The goal of these studies is to provide information that might, in turn, lead to new therapies. In this review, some previous studies were updated supporting the polygenic/multifactorial inheritance and the association with malignant neoplasias. We have also emphasized the importance of identifying the causative genes and determining novel diagnostic and predictive biomarkers.

Ovarian borderline tumors in the 2014 WHO classification: evolving concepts and diagnostic criteria

Borderline ovarian tumors (BOT) are uncommon but not rare epithelial ovarian neoplasms, intermediate between benign and malignant categories. Since BOT were first identified >40 years ago, they have inspired controversies disproportionate to their incidence. This review discusses diagnostic criteria for the histologic subtypes of BOT, highlighting areas of diagnostic challenges, ongoing controversies, and changes in terminology implemented by the recent 2014 WHO Classification of Tumours of the Female Genital Organs. Emerging knowledge supports the notion that subtypes of borderline ovarian tumors comprise distinct biologic, pathogenetic, and molecular entities, precluding a single unifying concept for BOT. Serous borderline tumors (SBT) share molecular and genetic alterations with low-grade serous carcinomas and can present at higher stages with peritoneal implants and/or lymph node involvement, which validates their borderline malignant potential. All other (non-serous) subtypes of BOT commonly present at stage I confined to the ovary(ies) and are associated with overall survival approaching that of the general population. An important change in the WHO 2014 classification is the new terminology of non-invasive implants associated with SBT, as any invasive foci (previously called “invasive implants”) are now in line with their biological behavior considered peritoneal low-grade serous carcinoma (LGSC). The controversy regarding the terminology of non-serous borderline tumors, called by some pathologists “atypical proliferative tumor” in view of their largely benign behavior, has not been resolved. The concepts of intraepithelial carcinoma and microinvasion may evolve in further studies, as their presence appears to have no prognostic impact and is subject to considerable inter-observer variability.

Ovarian and endometrial endometrioid carcinomas have distinct CTNNB1 and PTEN mutation profiles

Ovarian endometrioid carcinomas and endometrial endometrioid carcinomas share many histological and molecular alterations. These similarities are likely due to a common endometrial epithelial precursor cell of origin, with most ovarian endometrioid carcinomas arising from endometriosis. To directly compare the mutation profiles of two morphologically similar tumor types, endometrial endometrioid carcinomas (n=307) and ovarian endometrioid carcinomas (n=33), we performed select exon capture sequencing on a panel of genes: ARID1A, PTEN, PIK3CA, KRAS, CTNNB1, PPP2R1A, TP53. We found that PTEN mutations are more frequent in low-grade endometrial endometrioid carcinomas (67%) compared with low-grade ovarian endometrioid carcinomas (17%) (P<0.0001). By contrast, CTNNB1 mutations are significantly different in low-grade ovarian endometrioid carcinomas (53%) compared with low-grade endometrial endometrioid carcinomas (28%) (P<0.0057). This difference in CTNNB1 mutation frequency may be reflective of the distinct microenvironments; the epithelial cells lining an endometriotic cyst within the ovary are exposed to a highly oxidative environment that promotes tumorigenesis. Understanding the distinct mutation patterns found in the PI3K and Wnt pathways of ovarian and endometrial endometrioid carcinomas may provide future opportunities for stratifying patients for targeted therapeutics.

Genetic, epigenetic and stem cell alterations in endometriosis: new insights and potential therapeutic perspectives

Human endometrium is a highly dynamic tissue, undergoing periodic growth and regression at each menstrual cycle. Endometriosis is a frequent chronic pathological status characterized by endometrial tissue with an ectopic localization, causing pelvic pain and infertility and a variable clinical presentation. In addition, there is well-established evidence that, although endometriosis is considered benign, it is associated with an increased risk of malignant transformation in approximately 1.0% of affected women, with the involvement of multiple pathways of development. Increasing evidence supports a key contribution of different stem/progenitor cell populations not only in the cyclic regeneration of eutopic endometrium, but also in the pathogenesis of at least some types of endometriosis. Evidence has arisen from experiments in animal models of disease through different kinds of assays (including clonogenicity, the label-retaining cell approach, the analysis of undifferentiation markers), as well as from descriptive studies on ectopic and eutopic tissue samples harvested from affected women. Changes in stem cell populations in endometriotic lesions are associated with genetic and epigenetic alterations, including imbalance of miRNA expression, histone and DNA modifications and chromosomal aberrations. The present short review mainly summarizes the latest observations contributing to the current knowledge regarding the presence and the potential contribution of stem/progenitor cells in eutopic endometrium and the aetiology of endometriosis, together with a report of the most recently identified genetic and epigenetic alterations in endometriosis. We also describe the potential advantages of single cell molecular profiling in endometrium and in endometriotic lesions. All these data can have clinical implications and provide a basis for new potential therapeutic applications.

Chromosomal aberrations detected by chromogenic in situ hybridization in abdominal wall endometriosis after cesarean section

The goal of this study is to evaluate the chromosomal loss in abdominal wall endometriosis by chromogenic in situ hybridization (CISH). Twenty-four cases of abdominal wall endometriosis that developed after cesarean section at the Korea University Medical Center between January 1997 and December 2006 were selected. CISH was performed in the sections of tissue microarray block using the Zymed CISH centromeric probes for chromosomes 3, 7, 8, 9, 10, 11, 17, and 18. Monosomy was defined when the percentage of the nuclei with a single dot was more than mean+3 SD of the respective probe in normal control endometrium. CISH study was possible in more than half of the endometriosis samples, except for chromosome 9, and was most successful for chromosome 17. The frequency of monosomy was high for chromosomes 9 (75.0%) and 17 (73.9%), moderate for chromosomes 10 (57.1%) and 18 (56.3%), and low for chromosomes 3 (12.5%), 7 (22.2%), 8 (10.5%), and 11 (10.5%). Monosomy for >2 and 3 chromosomes occurred in 66.7% and 42.9% of the cases, respectively. It is concluded that CISH method may be considered a useful laboratory technique in detecting chromosomal loss, and multiple chromosomal loss is involved in the formation of ectopic endometrium in abdominal wall endometriosis.

The dichotomy in the histogenesis of endometriosis-associated ovarian cancer: clear cell-type versus endometrioid-type adenocarcinoma

The histogenesis of endometriosis and endometriosis-associated ovarian cancer is one of the most mysterious aspects of pathology. To better understand the histogenesis of endometriosis and endometriosis-associated ovarian cancer, we analyzed the possibility of a link of endometrium, ovarian surface epithelium, and a cortical inclusion cyst to ovarian endometriosis and endometriosis-associated ovarian cancer by immunohistochemistry using the epithelial membrane antigen (an epithelial marker), calretinin (a mesothelial marker), and hepatocyte nuclear factor (HNF)-1β (a clear cell carcinoma-specific transcription factor). During ovarian surface epithelium invagination, cortical inclusion cyst epithelial cells may, in some cases, undergo mesothelial-epithelial transition and subsequently differentiate into endometriosis. This case of endometriosis that has undergone Müllerian metaplasia arises from the HNF-1β-negative cells. The remaining endometriosis may develop from the late secretory and menstrual endometria, with HNF-1β-positive staining, by retrograde menstruation. Endometrioid adenocarcinoma and clear cell carcinoma arise from the HNF-1β-negative and HNF-1β-positive epithelial cells of endometriosis, respectively. It has been proposed that clear cell and endometrioid-type adenocarcinomas arise from distinct types of endometriosis with different cells of origin.

Ovarian clear cell carcinoma as a stress-responsive cancer: influence of the microenvironment on the carcinogenesis and cancer phenotype

Although it is well known that ovarian endometriosis occasionally gives rise to ovarian cancers with specific histology such as endometrioid and clear cell carcinomas, its etiology is not fully understood. We have shown that a stressful microenvironment within the endometriotic cyst may lead to cancer development by inducing unique gene expressions, which potentially serves as a molecular marker for treatment modality. In this review, by referring to other articles in this field, we explore how the carcinogenic microenvironment affects the phenotype and gene expression of a cancer, and how we can develop new treatment based on this concept.

The 'incessant menstruation' hypothesis: a mechanistic ovarian cancer model with implications for prevention

Serous, endometrioid, clear cell and mucinous histotypes are the most common epithelial ovarian cancer. Most serous cancers appear to originate from precursor lesions at the fimbriated tubal end, whereas most endometrioid and clear cell cancers seem to derive from atypical endometriosis. Data regarding hormonal factors and associated gynaecologic conditions were critically analysed with the objective of defining a carcinogenic model for sporadic epithelial ovarian cancer complying with epidemiologic and pathologic findings. Oral contraceptives and tubal ligation substantially reduce the risk of serous, endometrioid and clear cell subgroups, but have no significant effect on mucinous tumours, which probably follow a different oncogenic pathway. We hypothesize that serous, endometrioid and clear cell cancers share a common pathogenic mechanism, i.e. iron-induced oxidative stress derived from retrograde menstruation. Fimbriae floating in bloody peritoneal fluid are exposed to the action of catalytic iron and to the genotoxic effect of reactive oxygen species, generated from haemolysis of erythrocytes by pelvic macrophages. This would explain the distal site of tubal intraepithelial neoplasia. Collection of blood inside endometriomas would lead to the same type of genotoxic insult on gonadal endometrial implants. This would explain why endometriosis-associated cancers develop much more frequently in the ovary than at extragonadal sites. In women not seeking conception, bilateral salpingectomy could be advised whenever planning surgery for independent indications, thus possibly reducing cancer risk, while preserving ovarian function. The use of oral contraceptives should be favoured for prolonged periods of time, especially in women with endometriosis, a population at doubled risk of gonadal malignancy.

Pathogenesis of ovarian clear cell adenofibroma, atypical proliferative (borderline) tumor, and carcinoma: clinicopathologic features of tumors with endometriosis or adenofibromatous components support two related pathways of tumor development

The clinicopathologic features of 472 ovarian epithelial clear cell neoplasms (4 adenofibromas [AFs], 41 atypical proliferative [borderline] tumors [APTs], and 427 carcinomas [CAs]) were studied in order to elucidate the morphologic steps involved in the pathogenesis of these tumors and determine whether clear cell CA is a type I or type II tumor in the dualistic model of ovarian carcinogenesis. Thirty-three percent of the CAs had an adenofibromatous background [CA(AF+)], and 67% did not [CA(AF-)]. Endometriosis was found in all types of tumors, but tumors arising in endometriotic cysts were more frequent with CA(AF-)s (p<0.0001). The subset of women with CA(AF-)s with endometriosis were younger (p<0.0001), their tumors were more frequently cystic (p<0.0001), they more commonly had a mixed carcinoma component of non-clear cell type (p=0.006), and they were more frequently oxyphilic (p=0.015) compared with CA(AF+)s. The architecture of the former tumors was more commonly papillary compared to tubulocystic in the latter (p=0.0006). Atypical endometriosis was more common in CA(AF-)s than in AFs, APTs, and CC(AF+)s [p=0.004]. The subset of CA(AF-)s without endometriosis presented more frequently in advanced stage (>I) and were higher grade compared to CA(AF+)s or CA(AF-) with endometriosis (p-values, <0.0001 to 0.0071). All AFs and APTs were stage I compared to 79% of CA(AF+)s. An increase in mean tumor size correlated with each respective tumor category from AF (6.8 cm) to CA(AF+) [12.9 cm]. Notable nuclear atypia was absent in all AFs but was focally present in 27% of APTs and in the adenofibromatous background of 24% of the CA(AF+)s. An increase in the proportion of carcinoma in the CA(AF+)s correlated with an increase in grade and advanced stage. In summary, ovarian clear cell CA appears to develop along two pathways, both of which are related to endometriosis. We speculate that, in one, epithelial atypia arises in an endometriotic cyst and then evolves into clear cell CA, and, in the other, non-cystic endometriosis induces a fibromatous reaction resulting in the formation of AF, which then develops into APT and subsequently a clear cell CA. The absence of endometriosis or adenofibromatous components in CC(AF-)s may be due to overgrowth and obliteration by the invasive carcinoma. Finally, the findings in this study support the view that both types of clear cell CA [CC(AF+) and CC(AF-)] are more closely related to type I tumors.

Ovarian cancer in endometriosis: molecular biology, pathology, and clinical management

Recent molecular and pathological evidence suggests that endometriosis is a monoclonal, neoplastic disease. Moreover, endometriosis serves as a precursor of ovarian cancer (endometriosis-associated ovarian cancer; EAOC), especially of the endometrioid and clear cell subtypes. Although a variety of molecular events, such as p53 alteration, PTEN silencing, K-ras mutations, and HNF-1 activation, have been identified in EAOC, its precise carcinogenic mechanism remains poorly understood. Our recent data indicate that microenvironmental factors, including oxidative stress and inflammation, play an important role in the carcinogenesis and phenotype of EAOC. The management of endometriosis from the standpoint of EAOC is not standardized yet. To this end, clarification of the precise natural course and the risk factors that contribute to malignant transformation remain important goals. Among the phenotypes of EAOC, clear cell carcinoma, seems to require a specific treatment strategy, including molecular targeting.

MicroRNA expression profiling of eutopic secretory endometrium in women with versus without endometriosis

Endometriosis is a common gynecologic disorder characterized by pain and infertility. In addition to estrogen dependence, progesterone resistance is an emerging feature of this disorder. Specifically, a delayed transition from the proliferative to secretory phase as evidenced by dysregulation of progesterone target genes and maintenance of a proliferative molecular fingerprint in the early secretory endometrium (ESE) has been reported. MicroRNAs (miRNAs) are small noncoding RNAs that collectively represent a novel class of regulators of gene expression. In an effort to investigate further the observed progesterone resistance in the ESE of women with endometriosis, we conducted array-based, global miRNA profiling. We report distinct miRNA expression profiles in the ESE of women with versus without endometriosis in a subset of samples previously used in global gene expression analysis. Specifically, the miR-9 and miR-34 miRNA families evidenced dysregulation. Integration of the miRNA and gene expression profiles provides unique insights into the molecular basis of this enigmatic disorder and, possibly, the regulation of the proliferative phenotype during the early secretory phase of the menstrual cycle in affected women.

Serial analysis of gene expression reveals differential expression between endometriosis and normal endometrium. Possible roles for AXL and SHC1 in the pathogenesis of endometriosis

BACKGROUND

Endometriosis is a clinical condition that affects up to 10% of the women of reproductive age. Endometriosis is characterized by the presence of endometrial tissues outside the uterine cavity and can lead to chronic pelvic pain, infertility and, in some cases, to ovarian cancer.

METHODS

In order to better understand the pathogenesis of endometriosis, we have used Serial Analysis of Gene Expression (SAGE) to identify genes differentially in this disease by studying three endometriotic tissues and a normal endometrium sample. Promising candidates (AXL, SHC1, ACTN4, PI3KCA, p-AKT, p-mTOR, and p-ERK) were independently validated by immunohistochemistry in additional normal and endometriotic tissues.

RESULTS

We identified several genes differentially expressed between endometriosis and normal endometrium. IGF2, ACTN4, AXL, and SHC1 were among the most upregulated genes. Comparison of the endometriosis gene expression profiles with the gene expression patterns observed in normal human tissues allowed the identification of endometriosis-specific genes, which included several members of the MMP family (MMP1,2,3,10,11,14). Immunohistochemical analysis of several candidates confirmed the SAGE findings, and suggested the involvement of the PI3K-Akt and MAPK signaling pathways in endometriosis.

CONCLUSION

In human endometriosis, the PI3K-Akt and MAPK signaling pathways may be activated via overexpression of AXL and SHC1, respectively. These genes, as well as others identified as differentially expressed in this study, may be useful for the development of novel strategies for the detection and/or therapy of endometriosis.

Pelvic endometriosis is rarely associated with ovarian borderline tumours, cytologic and architectural atypia: a clinicopathologic study

Endometriotic foci, especially ovarian ones, with epithelial cytologic atypia may be precursors of cancer. This study presents an overview of the atypical cytological and histopathological findings associated with endometriosis. Six cases of endometriosis, with atypical histological and cytological changes, were obtained from the archives of the Department of Pathology at Cleveland Clinic Foundation between year 2000 and 2003. The size of the base from which these cases were drawn was 2000 cases of endometriosis. The age range of the patients was from 29 to 52 years. The clinical presentations included infertility (three cases), pelvic pain (three cases), adenexal and pelvic masses (four cases). Stage IV endometriosis with extensive pelvic involvement was found in two patients. Intraoperatively, the endometriotic lesions involved the ovaries (all cases); Cul de sac (four cases); urinary bladder (two cases); sigmoid colon, hemidiaphragms, and uterine vessels (one case each). The endometriotic lesions were associated with uterine leiomyomas (two patients) and adenocarcinoma of the vagina (one patient). Histologically, in addition to endometrial type glands and stroma, usually found in endometriosis, we observed both cytologic and pattern atypism involving the epithelium in all cases. The features of cytologic atypia included nuclear stratification, hyperchromatism, and pleomorphism. The features of pattern atypia were complex glandular pattern, papillary formations and psammoma bodies. In two cases, these features were sufficient for diagnosis of borderline Mullerian seromucinous tumours. One patient had recurred with metastatic adenocarcinoma of the vault. She died later from disseminated metastatic disease. There is a rare association between pelvic endometriosis and borderline ovarian tumours (three cases), cytologic and pattern atypia (two cases); mesothelial hyperplasia, endosalpingiosis (two cases), and metastasis (one case). Cytologic and pattern atypia can develop in the endometriotic foci and therefore, these lesions should be thoroughly scrutinized for presence of these changes. Our findings recommend surgical excision of these foci rather than their simple cauterization.

Genome profiling of ovarian adenocarcinomas using pangenomic BACs microarray comparative genomic hybridization

Background

Routine cytogenetic investigations for ovarian cancers are limited by culture failure and poor growth of cancer cells compared to normal cells. Fluorescence in situ Hybridization (FISH) application or classical comparative genome hybridization techniques are also have their own limitations in detecting genome imbalance especially for small changes that are not known ahead of time and for which FISH probes could not be thus designed.

Methods

We applied microarray comparative genomic hybridization (A-CGH) using one mega base BAC arrays to investigate chromosomal disorders in ovarian adenocarcinoma in patients with familial history.

Results

Our data on 10 cases of ovarian cancer revealed losses of 6q (4 cases mainly mosaic loss), 9p (4 cases), 10q (3 cases), 21q (3 cases), 22q (4 cases) with association to a monosomy X and gains of 8q and 9q (occurring together in 8 cases) and gain of 12p. There were other abnormalities such as loss of 17p that were noted in two profiles of the studied cases. Total or mosaic segmental gain of 2p, 3q, 4q, 7q and 13q were also observed. Seven of 10 patients were investigated by FISH to control array CGH results. The FISH data showed a concordance between the 2 methods.

Conclusion

The data suggest that A-CGH detects unique and common abnormalities with certain exceptions such as tetraploidy and balanced translocation, which may lead to understanding progression of genetic changes as well as aid in early diagnosis and have an impact on therapy and prognosis.

The pathology of endometriosis: a survey of the many faces of a common disease emphasizing diagnostic pitfalls and unusual and newly appreciated aspects

Although the histologic diagnosis of endometriosis is usually straightforward, many diagnostic problems can arise as a result of alterations or absence of its glandular or stromal components. The diagnostic difficulty in such cases can be compounded by tissue that is limited to a small biopsy specimen. The appearance of the glandular component can be altered by hormonal and metaplastic changes, as well as cytologic atypia and hyperplasia. Although the last 2 findings are often referred to collectively as "atypical endometriosis," they should be separately recognized as their premalignant potential likely differs. In some cases, the endometriotic glands are sparse or even absent (stromal endometriosis). The stromal component can be obscured or effaced by infiltrates of foamy and pigmented histiocytes, fibrosis, elastosis, smooth muscle metaplasia, myxoid change, and decidual change. Occasional findings in endometriosis that may raise concern for a neoplasm include necrotic pseudoxanthomatous nodules, polypoid growth (polypoid endometriosis), bulky disease, and venous, lymphatic, or perineural invasion. Inflammatory and reactive changes within, adjacent to, or at a distance from foci of endometriosis can complicate the histologic findings and include infection within endometriotic cysts, pseudoxanthomatous salpingitis, florid mesothelial hyperplasia, peritoneal inclusion cysts, and Liesegang rings. The histologic diagnosis of endometriosis can also be challenging when it involves an unusual or unexpected site. Five such site-specific problematic areas considered are endometriosis on or near the ovarian surface, superficial cervical endometriosis, vaginal endometriosis, tubal endometriosis, and intestinal endometriosis, including the important distinction of an endometrioid carcinoma arising from colonic endometriosis from a primary colonic adenocarcinoma. Finally, endometriotic foci can occasionally be intimately admixed with another process, such as peritoneal leiomyomatosis or gliomatosis, resulting in a potentially confusing histologic appearance.