Expression of differentiation and proliferation related proteins in epithelium of prophylactically removed ovaries from women with a hereditary female adnexal cancer predisposition

Effect of menopause on hormonal receptors in ampullae of the fallopian tube with a special reference to the p53 signature

Objectives

Age-related changes in the expression of hormonal receptors have not been well examined in the fallopian tube (FT). We herein report the effect of menopause on the hormone receptors in ampullae of the FTs (AFTs), in comparison with cortical inclusion cysts (CICs) of the ovary.

Methods

A total of 84 AFTs and 16 fimbriae of FTs, which were obtained from 26 premenopausal and 58 postmenopausal women; and 27 postmenopausal CICs were immunohistochemically studied for the expression of p53, Ki-67, estrogen receptor-alpha (ER-α), and progesterone receptor A (PRA). Apoptotic cells were identified using a TUNEL assay.

Results

Postmenopausal AFTs showed a significantly lower labeling index (LI) for Ki-67 (P<0.001), apoptosis (P=0.03), and PRA (P<0.001) than premenopausal AFTs. No significant correlation with immunohistochemical markers was found in premenopausal AFTs, but the LI for PRA was positively correlated with that for Ki-67 (P=0.004) and inversely with that for p53 (P=0.023) in postmenopausal AFTs. The expression of immunohistochemical markers was closely correlated between ampullae and fimbriae of the FT. The p53 signature (p53S) was detected in five postmenopausal AFTs (mean age: 70.2 years) and was not detected in any CICs. The immunohistochemical profile of p53S was low expression of Ki-67, apoptosis, and PRA, and high expression of ER-α. The expression of PRA in CICs was significantly higher than that in AFTs (P=0.001).

Conclusion

The expression of PRA was significantly lower in postmenopausal AFTs than in premenopausal AFTs, whereas the expression of PRA was well preserved in postmenopausal CICs.

Estrogen and androgen receptor expression in surface epithelium and inclusion cyst in the ovary of premenopausal and postmenopausal women

BACKGROUND

The importance of surface epithelium and epithelial inclusion cysts in the ovary arises from studies demonstrating that these structures are susceptible to epithelial ovarian cancer development. The expression of estrogen receptor alpha (ER alpha), androgen receptor (AR), in epithelial cells of the ovary from premenopausal and postmenopausal women is interesting because sexual steroid hormones are involved in cell growth and differentiation.

METHODS

The presence of ER alpha, AR, and the orphan G protein-coupled receptor 30 (GPR30) was demonstrated by immunofluorescence in ovaries obtained from 79 pre and postmenopausal patients, undergoing histero-salpingo-oophorectomy for proliferative gynecological diseases. The proportion of patients that displayed positive reaction for estrogen and androgen receptors in epithelial cells of the ovary was evaluated according to menopausal status and associated pathology.

RESULTS

The proportion of patients that displayed a positive receptor expression in the epithelial cells of the ovarian surface and cortical inclusion cysts shows that ER alpha is present in 20 of 79 patients (0.25), AR in 33 of 79 (0.42) and GPR30 in 38 of 55 (0.69). There are no differences in ER alpha, AR, and GPR30 expression between pre and postmenopausal patients and considering the associated pathology, proportions for ER alpha and GPR30 are similar. The patients with cervical cancer show a higher proportion of AR expression in epithelial cells of the ovary, which is statistically significant (P < 0.01) compared with patients with other proliferative diseases.

CONCLUSIONS

The presence of ER alpha, AR, and GPR30 in the surface epithelial ovarian cells and its derivatives are observed with a proportion that is specific for each receptor. The proportion of expression for these receptors in the epithelial cells of the ovary does not change after menopause. The proportion of ovaries with AR positive epithelial cells in patients with cervical squamous carcinoma is higher compared with other gynecological pathologies.

Is There a Relationship between Ovarian Epithelial Dysplasia and Infertility?

Aim. Ovarian epithelial dysplasia was initially described in material from prophylactic oophorectomies performed in patients at genetic risk of ovarian cancer. Similar histopathological abnormalities have been revealed after ovulation stimulation. Since infertility is also a risk factor for ovarian neoplasia, the aim of this study was to study the relationship between infertility and ovarian dysplasia. Methods. We blindly reviewed 127 histopathological slides of adnexectomies or ovarian cystectomies according to three groups-an exposed group to ovulation induction (n = 30), an infertile group without stimulation (n = 35), and a spontaneously fertile control group (n = 62)-in order to design an eleven histopathological criteria scoring system. Results. The ovarian dysplasia score was significantly higher in exposed group whereas dysplasia score was low in infertile and control groups (resp., 8.21 in exposed group, 3.69 for infertile patients, and 3.62 for the controls). In the subgroup with refractory infertility there was a trend towards a more severe dysplasia score (8.53 in ovulation induction group and 5.1 in infertile group). Conclusion. These results raise questions as to the responsibility of drugs used to induce ovulation and/or infertility itself in the genesis of ovarian epithelial dysplasia.

Promoter hypermethylation patterns in fallopian tube epithelium of BRCA1 and BRCA2 germ line mutation carriers

BRCA1/2 germ line mutation carriers have a high risk of developing fallopian tube carcinoma (FTC), thought to occur through different early (p53 signatures) and later (dysplasia, intra-epithelial carcinoma) premalignant stages. Promoter hypermethylation of tumour suppressor genes is known to play a key role in (early) carcinogenesis. However, little is known about methylation in normal and (pre)malignant fallopian tube tissue. We identified 14 areas of p53 accumulation in the fallopian tubes of BRCA mutation carriers. Cells from these areas were harvested together with cells from adjacent benign appearing areas. An age-matched non-BRCA sporadic control group (n=13) and eight sporadic FTCs were included as negative and positive controls respectively. Methylation-specific multiplex ligation-dependent probe amplification was used to assess promoter methylation of 70 tumour suppressor genes in all samples. We observed a gradual increase in methylation from sporadic control tissue (median cumulative methylation index (CMI) 568.19) through normal tissue and from areas of p53 accumulation in BRCA carriers (median CMI 687.54 and 676.72) to FTC (median CMI 780.97). Furthermore, the methylation percentage of many individual tumour suppressor genes differed significantly between these groups, gradually increasing as for CMI. Between areas with and without p53 accumulation in BRCA mutation carriers no significant differences were found. In this paper, we have shown that BRCA mutation carriers display increased methylation of tumour suppressor genes in their non-malignant fallopian tube epithelium, closer to methylation levels in FTC than to normal sporadic tissue. Methylation could, therefore, play an important role in the increased risk of gynaecological malignancies in BRCA mutation carriers.

Decreased progesterone receptor isoform expression in luteal phase fallopian tube epithelium and high-grade serous carcinoma

We previously reported that BRCA1/2-mutated fallopian tube epithelium (FTE) collected during the luteal phase exhibits gene expression profiles more closely resembling that of high-grade serous carcinoma (HGSC) specimens than FTE collected during the follicular phase or from control patients. Since the luteal phase is characterised by high levels of progesterone, we determined whether the expression of progesterone receptor (PR) and PR-responsive genes was altered in FTE obtained from BRCA mutation carriers during the luteal phase of the menstrual cycle. RT-qPCR confirmed a decreased expression of PR mRNA in FTE during the luteal phase relative to follicular phase, in both BRCA1/2 mutation carriers and control patients. Immunohistochemistry using isoform-specific antibodies confirmed a low level of both PR-A and PR-B in HGSC and a lower level of staining in FTE samples obtained during the luteal phase compared with the follicular phase. No significant difference in PR-A or PR-B staining was found based on patient BRCA mutation status. Analysis of our previously reported gene expression profiles based upon known PR-A- and PR-B-specific target genes did not partition samples by BRCA mutation status, indicating that overall FTE PR response is not altered in BRCA mutation carriers. HGSC samples grouped separately from other samples, consistent with the observed loss of PR expression. These findings indicate no overall difference in PR signalling in FTE as a function of BRCA mutation status. Thus, the molecular similarity of BRCA1/2-mutated luteal phase FTE and HGSC likely results from an altered response to luteal phase factors other than progesterone.

Dynamics of the primate ovarian surface epithelium during the ovulatory menstrual cycle

BACKGROUND

Epithelial ovarian cancer (EOC) risk correlates strongly with the number of ovulations that a woman experiences. The primary source of EOC in women is the ovarian surface epithelium (OSE). Mechanistic studies on the etiology of OSE transformation to EOC cannot be realistically performed in women. Selecting a suitable animal model to investigate the normal OSE in the context of ovulation should be guided by the model's reproductive similarities to women in natural features that are thought to contribute to EOC risk.

METHODS

We selected the non-human primate, rhesus macaque, as a surrogate to study the normal OSE during the natural menstrual cycle. We investigated OSE morphology and marker expression, plus cell proliferation and death in relation to menstrual cycle stage and ovulation.

RESULTS

OSE cells displayed a morphological range from squamous to columnar. Cycle-independent parameters and cycle-dependent changes were observed for OSE histology, steroid receptor expression, cell death, DNA repair and cell adhesion. Contrary to findings in non-primates, primate OSE cells were not manifestly cleared from the site of ovulation, nor were proliferation rates affected by ovulation or stage of the menstrual cycle. DNA repair proteins were more highly expressed in OSE than in other ovarian cells.

CONCLUSIONS

This study identifies significant differences between primate and non-primate OSE. In contrast to established views, ovulation-induced death and proliferation are not indicated as prominent contributors to EOC risk, but disruption of OSE cadherin-mediated adhesion may be, as could the loss of ovary-mediated chronic suppression of proliferation and elevation of DNA repair potential.

The molecular pathogenesis of hereditary ovarian carcinoma: alterations in the tubal epithelium of women with BRCA1 and BRCA2 mutations

BACKGROUND

BRCA1 or BRCA2 (BRCA1/2)-mutated ovarian carcinomas may originate in the fallopian tube. The authors of this report investigated alterations in BRCA1/2 tubal epithelium to define the molecular pathogenesis of these carcinomas.

METHODS

Tubal epithelium was evaluated from 31 BRCA1/2 mutation carriers with gynecologic carcinomas (BRCA CA), 89 mutation carriers who underwent risk-reducing salpingo-oophorectomy (RRSO), and 87 controls. Ki-67 expression and p53 foci (≥10 of 12 consecutive staining cells) were scored by 2 investigators who were blinded to patient designations. Expression levels of p27 and p21 were evaluated within p53 foci. Loss of heterozygosity at the BRCA1/2 mutation site was evaluated in microdissected p53 foci and tubal neoplasms.

RESULTS

Background tubal proliferation as measured by Ki-67 staining was increased in the BRCA1 RRSO group (P = .005) compared with the control group. Women who had BRCA1/2 mutations had more p53 foci identified per tubal segment than women in the control group (P = .02). Levels of p27 were decreased in 12 of 28 p53 foci from women with BRCA1 mutations and in 0 of 16 p53 foci from controls (P = .002). There was no loss of the wild type BRCA1/2 allele in 5 tested p53 foci. Tubal neoplasia lost the wild type allele in 6 of 6 foci (P = .002).

CONCLUSIONS

The current results suggested a model of tubal carcinogenesis in women with BRCA1/2 mutations. Increased proliferation occurred globally in at-risk tubal epithelium. A mutation in the tumor protein p53 gene TP53 with clonal proliferation and loss of p27 occurred before neoplastic proliferation. Loss of the wild type BRCA1/2 allele occurred with neoplastic proliferation and before invasion.

Does bilateral salpingectomy with ovarian retention warrant consideration as a temporary bridge to risk-reducing bilateral oophorectomy in BRCA1/2 mutation carriers?

Risk-reducing salpingo-oophorectomy (RRSO) is the most definitive surgical intervention for ovarian cancer risk reduction among BRCA1/2 mutation carriers. For women who have completed child-bearing but who are not ready for RRSO, bilateral salpingectomy with ovarian retention (BSOR) might serve as a temporary measure while definitive risk-reducing surgery is being contemplated. Here we summarize recent insights into the pathogenesis of hereditary ovarian cancer that might provide a basis for consideration of the proposed BSOR management strategy and outline the evidence for and against this potential risk-reducing intervention. Based on the evidence, we suggest that there may be sufficient merit in this proposed intervention to consider evaluating it formally, perhaps through an intergroup-based clinical trial. In the meanwhile, we believe that BSOR should be considered an investigational risk management option of unproven clinical usefulness, particularly because delay in bilateral oophorectomy theoretically could reduce the protective effect against breast cancer that has been documented in women who have undergone RRSO.

Peri- and post-menopausal incidental adnexal masses and the risk of sporadic ovarian malignancy: new insights and clinical management

Adnexal masses are common among peri- and post-menopausal women. Although ovarian cancer is a significant cause of mortality in menopausal women, large population-based studies demonstrate that the majority of adnexal masses are benign. Despite this, the appearance of an adnexal mass is a concern for the patient and an insight exercise for physicians. In most cases, an adnexal enlargement is an incidental finding, generally corresponding to a benign cyst and easily diagnosed by conventional ultrasound. Exceptionally an ovarian tumour may be malignant and should be treated as early as possible. When conventional ultrasound renders complex morphology other diagnostic tools must be used such as: colour Doppler and functional tumour vessel properties, serum CA 125 levels, nuclear magnetic resonance imaging and in some cases laparoscopy. Several new tumour markers are being studied for clinical application, although there are presently no clear recommendations. Adnexal masses with benign morphological and functional properties must be periodically monitored as an alternative to surgery since malignant transformation is exceptional.

Hereditary ovarian carcinoma: heterogeneity, molecular genetics, pathology, and management

Hereditary ovarian cancer accounts for at least 5% of the estimated 22,000 new cases of this disease during 2009. During this same time, over 15,000 will die from malignancy ascribed to ovarian origin. The bulk of these hereditary cases fits the hereditary breast-ovarian cancer syndrome, while virtually all of the remainder will be consonant with the Lynch syndrome, disorders which are autosomal dominantly inherited. Advances in molecular genetics have led to the identification of BRCA1 and BRCA2 gene mutations which predispose to the hereditary breast-ovarian cancer syndrome, and mutations in mismatch repair genes, the most common of which are MSH2 and MLH1, which predispose to Lynch syndrome. These discoveries enable relatively certain diagnosis, limited only by their variable penetrance, so that identification of mutation carriers through a comprehensive cancer family history might be possible. This paper reviews the subject of hereditary ovarian cancer, with particular attention to its molecular genetic basis, its pathology, and its phenotypic/genotypic heterogeneity.

New insights into the pathogenesis of serous ovarian cancer and its clinical impact

There are only a handful of concepts concerning cancer and carcinogenesis that are currently beyond dispute. One such dogma is the adenoma-carcinoma sequence and that a multistep accumulation of genetic alterations is required for transformation from a benign to a neoplastic tissue. The inevitable derivative of this dogma is that every invasive carcinoma is in fact a missed intraepithelial tumor, and furthermore, a late evolutionary stage in the sequence of development from a precursor lesion. Until fairly recently, high-grade serous ovarian carcinoma seemed to be one of the only known deviants of these concepts. In this article, we discuss the emergence of the fallopian tube fimbria as a field of origin for high-grade serous carcinomas and present a binary model of ovarian cancer pathogenesis that takes into consideration prior epidemiologic, morphologic, and genetic data. With the rise of the fallopian tube secretory epithelial cell as a cell of origin for high-grade pelvic serous carcinomas, the need to develop tools and model systems to characterize the biology and physiology of this cell is recognized.

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.

Activation of BTAK expression in primary ovarian surface epithelial cells of prophylactic ovaries

The ovarian epithelial cells carrying heterozygous BRCA1 or BRCA2 mutation (we called BRCA1/2 mutation) are known to predispose to the development of ovarian cancer; however, the molecular basis of such predisposition is largely unknown. We hypothesize that BTAK may be a potential target for heterozygous BRCA1/2 mutation. We sought to determine the relationship between the status of BRCA1/2 heterozygous mutation and BTAK expression in prophylactically removed ovaries as compared with normal ovaries and ovarian cancer controls. Western blot analysis of BTAK was performed in a primary cell culture carrying heterozygous BRCA1 mutation and three normal ovarian surface epithelial cell cultures. Immunohistochemical analysis of BTAK expression was also performed by image analysis in ovaries of 21 patients with known BRCA1/2 mutation or very strong family history of breast/ovarian cancer that underwent prophylactic oophorectomy, 38 normal ovaries from patients without any known mutation, and 194 ovarian carcinomas. The BTAK expression was significantly increased in primary culture carrying a heterozygous BRCA1 mutation as compared to those with no known BRCA1/2 mutation. Immunohistochemical staining of BTAK showed increased expression in ovarian epithelial cells carrying BRCA1/2 mutation or strong breast/ovarian family history compared with normal ovaries (P<0.001). Higher BTAK expression was found in ovarian cancer cells compared to ovaries without cancer but with known BRCA1/2 mutation or strong family history (P<0.001), and expression levels of BTAK and p53 were directly correlated (r=0.306; P<0.001). Increased expression of BTAK is directly correlated with mutation status of BRCA1/2 genes, suggesting that mutation in a single allele of either BRCA1 or 2 may be responsible for the activation of BTAK. This activation may be a key early genetic event in the development of hereditary ovarian cancer.

Immunohistochemical and functional biomarkers of value in female genital tract lesions

There has been a marked expansion in the literature pertaining to the use of immunohistochemical markers in female genital tract pathology, especially with regard to diagnosis. This review provides a survey of the antibodies commonly used in the diagnosis of gynecological lesions grouped as to function or type. Prognostic or predictive markers are also discussed where appropriate, although few of these are of value in everyday practice. It is stressed that when immunohistochemistry is used diagnostically, panels of markers provide better information than reliance on a single antibody.

Low prevalence of (pre) malignant lesions in the breast and high prevalence in the ovary and Fallopian tube in women at hereditary high risk of breast and ovarian cancer

To analyse the prevalence of (pre) malignant lesions occurring in breast and adnexal tissue at prophylactic surgery in women at hereditary high risk of breast and/or ovarian cancers. Tissue was obtained from 85 women who underwent prophylactic bilateral salpingo-oophorectomy (pBSO) and from 59 women who underwent prophylactic mastectomy (pM). Control tissue samples were obtained from women undergoing breast reduction surgery (N = 99) or adnexal surgery for benign reasons (N = 72). In women with a BRCA1/2 mutation, the prevalence of a (pre) malignant adnexal lesion was 50% (95% CI 26-74) if older than 40 years and 14% (95% CI 0-58) if younger. The prevalences of (pre) malignant breast lesions in women older than 40 years, with and without a BRCA1/2 mutation, were 0% (95% CI 0-16) and 47% (95% CI 21-73), respectively. No association was found between (pre) malignant lesions in breast and adnexal tissue occurring in 28 women who underwent surgery on both organs (R = 0.155, p = 0.432), but the prevalence of lesions was significantly higher in adnexal tissue than in the breast (p = 0.023). Compared to controls, women at hereditary high risk had a higher chance of (pre) malignant lesions in the breast and an even higher chance of such lesions in the adnexal tissue. There was no indication for concomitant presence of such lesions in both organs at the time of prophylactic surgery. The high frequency of (pre) malignant lesions in the adnexal tissue stresses further the importance of pBSO from the age of 40 onwards in women at hereditary high risk.

Advances in the recognition of tubal intraepithelial carcinoma: applications to cancer screening and the pathogenesis of ovarian cancer

Prophylactic salpingo-oophorectomies from women with BRCA mutations (BRCA+) have identified the tube as a frequent site of early pelvic serous carcinoma (tubal intraepithelial carcinoma [TIC]). These observations have implications for both the early recognition of pelvic serous carcinoma in susceptible women and determining the ultimate site of origin for pelvic serous carcinomas. Moreover, the unique pathology of TIC has shifted attention from the more exuberant proliferations mentioned in prior studies to a spectrum of neoplastic atypias that can be morphologically subtle. This review addresses a multitude of epithelial changes; benign, malignant, and an intriguing third group, which we term "p53 signatures," is found in benign, nonciliated epithelium and stain intensely positive for p53. Understanding all 3 is important for the proper management of women undergoing prophylactic salpingo-oophorectomy and possibly formulating an integrated model for the pathogenesis of serous carcinoma in the reproductive tract. A protocol for sectioning and extensively examining the fimbriated end (SEE-FIM), and its rationale, is described.

Expression of cell cycle regulatory proteins in ovaries prophylactically removed from Jewish Ashkenazi BRCA1 and BRCA2 mutation carriers: Correlation with histopathology

OBJECTIVES

Prophylactic oophorectomy in Ashkenazi Jewish women with BRCA mutations represents a unique opportunity to search for premalignant changes in ovaries. Reports on the presence of dysplastic lesions in these ovaries are contradictory. Our aim was to study the expression of cell cycle regulatory proteins--p53, Skp2, p27, Ki67, Bcl2 and p16--in correlation with histopathological changes. p16(INK4A) was not studied before in prophylactically removed ovaries.

METHODS

Ninety-four ovaries from 50 Ashkenazi Jewish BRCA carriers were compared with 42 ovaries removed for reasons unrelated to cancer and with 16 ovarian carcinomas.

RESULTS

Three (6%) patients from the high-risk group had an occult carcinoma. A significant association was found between BRCA-positive expression and the presence of atypical changes in the superficial ovarian epithelium (P = 0.014) as well as the presence of epithelial cortical clefts (P = 0.042). Expression of p53 in cortical inclusions was significantly higher in the BRCA-positive cases than in the benign control group (P = 0.03). The high-risk and the benign control group did not differ significantly by the expression of p16, BCL2, Ki67, p27 and SKP2 (P > 0.05). However, both groups significantly differed from the carcinoma group (P < 0.0001). A significant positive correlation was found between the expression of Ki67, and the grade of atypia in the high-risk group (R = 0.3, P = 0.01) and in the benign control group (R = 0.5, P = 0.02).

CONCLUSIONS

BRCA mutation carriers had more atypical changes in the superficial epithelium (P = 0.014) and more epithelial cortical clefts (P = 0.042) compared to the benign control group. The histopathology changes were not supported by significantly altered expressions of the proteins used in our study. Additional molecular studies could contribute to the disclosure of precancerous ovarian lesions.

Steroid signalling in the ovarian surface epithelium

Human ovarian surface epithelium (HOSE) undergoes serial injury-repair with each ovulation, which is probably why most ovarian epithelial cancers arise there. Considering the proposed inflammatory aetiology of ovarian cancer, anti-inflammatory steroid signalling might be vital for HOSE regulation. HOSE cells express hydroxysteroid dehydrogenase (HSD) enzymes that undertake prereceptor metabolism of bioinert steroidogenic precursors formed elsewhere in the body. Ovulation-associated cytokines activate anti-inflammatory cortisol from precursor cortisone in HOSE cells owing to up-regulation of the gene encoding 11betaHSD type 1 (HSD11B1) in vitro. Cortisol further enhances its own formation and action through augmentation of cytokine-induced HSD11B1 and glucocorticoid receptor gene expression. Understanding this feed-forward signalling process has implications for the improved diagnosis and treatment of inflammation-associated reproductive disease states such as ovarian cancer.

Origins and molecular pathology of ovarian cancer

Epithelial ovarian cancer comprises the majority of malignant ovarian tumors in adult women. These neoplasms are classified into distinct morphologic categories based on the appearance of the epithelium into tumors of serous, mucinous, endometrioid, clear cell, transitional, squamous, mixed and undifferentiated type. Current data indicate that each of these histologic subtypes is associated with distinct morphologic and molecular genetic alterations: high-grade serous and possibly endometrioid carcinomas most probably arise from surface epithelial inclusion glands with TP53 mutations and dysfunction of BRCA1 and/or BRCA2; low-grade serous carcinomas probably arise in a stepwise fashion in an adenoma-borderline tumor-carcinoma sequence from typical to micropapillary borderline tumors to low-grade invasive serous carcinoma via activation of the RAS-RAF signaling pathway secondary to mutations in KRAS and BRAF; mucinous carcinomas arise via an adenoma-borderline tumor-carcinoma sequence with mutations in KRAS; low-grade endometrioid carcinomas arise from endometriosis via mutations in CTNNB1 (the gene encoding beta-catenin) and PTEN. Although the morphologic data strongly support an origin of clear cell carcinoma from endometriosis, there is limited data on the genetic alterations in these uncommon tumors. Thus it is likely that most low-grade, relatively indolent ovarian carcinomas of serous, mucinous and endometrioid type arise from pre-existing cystadenomas or endometriosis whereas most high-grade serous carcinomas arise without an easily identifiable precursor lesion.

Intraperitoneal serous adenocarcinoma: a critical appraisal of three hypotheses on its cause

OBJECTIVE

Serous ovarian, Fallopian tube, and peritoneal adenocarcinomas are remarkably similar, both in their morphology, as well as in their clinical behavior. Despite extensive clinical and fundamental research, controversy still exists on the origin of serous female adnexal tumors. Difficulties in identification of site of origin at late stage the of disease at detection, when ovary, Fallopian tube, and the abdominal cavity are usually all involved, in addition to their macroscopic and microscopic resemblance, are major causes of this debate. In 3 hypotheses, 3 possible tissues of origin are proposed: the ovarian surface epithelium, the Fallopian tube epithelium, and the secondary Mullerian system.

STUDY DESIGN

We searched for all peer-reviewed articles and reviews that examined "serous ovarian carcinoma," "Fallopian tube carcinoma," "Mullerian system," "ovarian surface epithelium," "tubal epithelium," and "peritoneal." We included only articles that could give information on the origin of serous carcinomas. Additional articles were added by examining references of overview articles in relevant fields.

RESULTS

Discussed are the experimental data underlying these hypotheses.

CONCLUSION

An attempt is made to integrate the 3 hypotheses into a comprehensive model of serous intraperitoneal adenocarcinogenesis. It can be concluded that the Fallopian tubes play a major role in the development of female serous cancer.

Cultures of ovarian surface epithelium from women with and without a hereditary predisposition to develop female adnexal carcinoma

AIM

Conflicting evidence exists on whether in vivo morphological characteristics can distinguish Ovarian Surface Epithelium (OSE) of ovaries obtained from women with and without a predisposition to develop female adnexal (ovarian and fallopian tube) carcinoma. This study aims to detect differences in growth potential and morphology that are maintained or specifically expressed in vitro.

STUDY DESIGN

Ovarian surfaces were scraped to retrieve OSE cells from 56 women at hereditary high risk for female adnexal carcinoma, of whom 33 are BRCA1 and four are BRCA2 mutation carriers (Predisposed OSE, POSE) and from 26 women without such risk (Non Predisposed OSE, NPOSE). Number of passages and total cell yield until last passage, as well as morphology was compared between both groups. To confirm morphology, the expression of epithelial, mesothelial, and fibroblast markers was assessed.

RESULTS

Both POSE and NPOSE cultures displayed similar growth potential and morphology. The expression of epithelial markers cyto-keratins 7 and 8 was similar between both groups. Only in cultures in which cells did not uniformly exhibit these markers, the percentage of cells expressing these markers was significantly lower at last passage when compared to the initial culture. In these latter cultures, cells that were morphologically indistinguishable from fibroblasts were observed. Mesothelial marker calretinin was expressed in 75% of cells of both POSE and NPOSE cultures and correlates with cyto-keratins 7 and 8 expression. CA 125 expression was equally low in POSE and NPOSE cultures (4.3%). Fibroblast markers FSM and vimentin were expressed in 100% and collagen IV was expressed in 16% of cells in all cultures.

CONCLUSION

OSE cells derived from women with a hereditary predisposition to develop female adnexal cancer possess similar in vitro characteristics as OSE from women without this predisposition. On basis of our results, it seems advisable to study only 100% cyto-keratins 7 and 8 positive OSE cultures, since contamination of fibroblasts in some primary OSE cultures cannot be ruled out.