A pathologist's road map to benign, precancerous, and malignant intraepithelial proliferations in the fallopian tube

Opportunistic salpingectomy at the time of vaginal hysterectomy: A systematic review and meta-analysis

BACKGROUND

Despite the rising rates of opportunistic salpingectomy at the time of surgery for non-malignant conditions, salpingectomy is not widely adopted during vaginal hysterectomy (VH) and has not been extensively investigated.

OBJECTIVES

The aim of the primary study was to determine the feasibility of bilateral opportunistic salpingectomy at the time of VH. Secondary aims included surgical outcomes, factors associated with patient selection, and the prevalence of incidental tubal malignancies.

SEARCH STRATEGY

In this systematic review and meta-analysis we searched Pubmed, Embase and ClinicalTrials.gov databases from inception to September 1, 2023, using relevant keywords.

SELECTION CRITERIA

Original articles with no language restriction reporting outcomes of women undergoing planned VH with opportunistic salpingectomy, were considered eligible. Studies including patients undergoing VH with and without opportunistic salpingectomy were also included.

DATA COLLECTION AND ANALYSIS

The Newcastle-Ottawa scale was used to assess quality of observational studies. DerSimonian-Laird random effects meta-analysis was performed and pooled effect estimates and proportions with corresponding 95% confidence intervals were computed. Heterogeneity was assessed using the I2 statistic.

RESULTS

Seven observational cohort studies including 4808 women undergoing opportunistic salpingectomy at the time of VH and 10 295 patients undergoing VH alone were selected. The pooled proportion of success was 81.83 per 100 observations (95% CI: 75.35-87.54). Opportunistic salpingectomy at the time of VH, when feasible, was associated with a significant reduction in intraoperative complications (OR 0.06, 95% CI: 0.01, -0.37, P = 0.03) and total operative time (95% CI: -17.80, -1.07, P = 0.03) compared to those where it failed. Successful salpingectomy was significantly hindered by nulliparity (OR 0.12, 95% CI: -17.69, -1.21, P < 0.001) and favored by pelvic organ prolapse (OR 3.20, 95% CI: 1.35, 7.55, P = 0.008). Immunohistochemical tubal abnormalities were found in 13/579 (2.1%) patients. The overall quality of the evidence, according to the GRADE assessment, was low.

CONCLUSION

Opportunistic salpingectomy is safe, effective, and feasible at the time of VH. Nulliparity and pelvic organ prolapse are factors potentially influencing surgical outcomes.

Early Detection of Ovarian Cancer

The risk of death from ovarian cancer is highly associated with the clinical stage at diagnosis. Efforts to implement screening for ovarian cancer have been largely unsuccessful, due to the low prevalence of the disease in the general population and the heterogeneity of the various cancer types that fall under the ovarian cancer designation. A practical test for early detection will require both high sensitivity and high specificity to balance reducing the number of cancer deaths with minimizing surgical interventions for false positive screens. The technology must be cost-effective to deliver at scale, widely accessible, and relatively noninvasive. Most importantly, a successful early detection test must be effective not only at diagnosing ovarian cancer but also in reducing ovarian cancer deaths. Stepwise or multimodal approaches among the various areas under investigation will likely be required to make early detection a reality.

Increased FOXJ1 protein expression is associated with improved overall survival in high-grade serous ovarian carcinoma: an Ovarian Tumor Tissue Analysis Consortium Study

BACKGROUND

Recently, we showed a >60% difference in 5-year survival for patients with tubo-ovarian high-grade serous carcinoma (HGSC) when stratified by a 101-gene mRNA expression prognostic signature. Given the varied patient outcomes, this study aimed to translate prognostic mRNA markers into protein expression assays by immunohistochemistry and validate their survival association in HGSC.

METHODS

Two prognostic genes, FOXJ1 and GMNN, were selected based on high-quality antibodies, correlation with protein expression and variation in immunohistochemical scores in a preliminary cohort (n = 134 and n = 80, respectively). Six thousand four hundred and thirty-four (FOXJ1) and 5470 (GMNN) formalin-fixed, paraffin-embedded ovarian neoplasms (4634 and 4185 HGSC, respectively) represented on tissue microarrays from the Ovarian Tumor Tissue Analysis consortium underwent immunohistochemical staining and scoring, then univariate and multivariate survival analysis.

RESULTS

Consistent with mRNA, FOXJ1 protein expression exhibited a linear, increasing association with improved overall survival in HGSC patients. Women with >50% expression had the most favourable outcomes (HR = 0.78, 95% CI 0.67-0.91, p < 0.0001). GMNN protein expression was not significantly associated with overall HSGC patient survival. However, HGSCs with >35% GMNN expression showed a trend for better outcomes, though this was not significant.

CONCLUSION

We provide foundational evidence for the prognostic value of FOXJ1 in HGSC, validating the prior mRNA-based prognostic association by immunohistochemistry.

Serous tubal intraepithelial carcinoma: What Do We Really Know at this Point?

Serous tubal intraepithelial carcinoma (STIC) is the earliest morphologically recognizable step in the development of invasive high-grade serous carcinoma of the fallopian tube. Lesions occurring prior to STIC within the carcinogenic sequence for the pathogenesis of invasive high-grade serous carcinoma include the p53 signature and secretory cell outgrowth (SCOUT). Variable histologic criteria have been used for diagnosing STIC, but a combination of morphology and immunohistochemistry for p53/Ki-67 improves interobserver agreement. Half of all carcinomas identified in risk-reducing salpingo-oophorectomy specimens are in the form of STIC; however, STIC also may be incidentally found on occasion in specimens from women at low or average risk of ovarian/tubal/peritoneal carcinoma. TP53 mutation is the earliest known DNA sequence alteration in STIC and almost all invasive high-grade serous carcinomas of the ovary and peritoneum. Data on the clinical behavior of STIC are limited. While the short-term follow-up in the prior literature suggests a low risk of malignant progression, a more recent meta-analysis indicates a 10-year risk of 28%. STIC probably should be best regarded as a lesion with uncertain malignant potential at present, and future molecular analysis will help classify those with higher risk of dissemination. This review article provides an update on the current knowledge of STIC and related issues.

Pathology of Hereditary Breast and Ovarian Cancer

Hereditary breast and ovarian cancer (HBOC) syndrome is most commonly characterized by deleterious germline mutations in BRCA1 and BRCA2. HBOC patients are prone to the development of malignant neoplasms in multiple organs including the breast, ovary, and fallopian tube. From a pathological perspective, a number of morphological features have been described in BRCA-associated breast and tubo-ovarian cancers. For example, breast cancers diagnosed in BRCA1-mutation carriers are frequently of a high Nottingham grade and display medullary morphology and a triple-negative and/or a basal-like immunophenotype. In contrast, breast cancers in BRCA2-mutation carriers are similar to sporadic luminal-type tumors that are positive for hormone receptors and lack expression of human epidermal growth factor receptor 2. Cancers arising in the fallopian tube and ovary are almost exclusively of a high-grade serous histotype with frequent Solid, pseudo-Endometrioid, and Transitional cell carcinoma-like morphology (“SET features”), marked nuclear atypia, high mitotic index, abundant tumor infiltrating lymphocytes, and necrosis. In addition, pushing or infiltrative micropapillary patterns of invasion have been described in BRCA-associated metastases of tubo-ovarian high-grade serous carcinomas. Besides BRCA1 and BRCA2 mutations, alterations in a number of other homologous recombination genes with moderate penetrance, including PALB2, RAD51C, RAD51D, BRIP1, and others, have also been described in HBOC patients with varying frequency; however, distinct morphological characteristics of these tumors have not been well characterized to date. In this review, the above pathological features are discussed in detail and a focus is placed on how accurate pathologic interpretation plays an important role in allowing HBOC patients to receive the best possible management.

Rationale for opportunistic salpingectomy during gynecological surgery for a benign condition: A review of the available literature

INTRODUCTION

Recent discoveries have shed light on the benefits of opportunistic salpingectomy in the prevention of ovarian cancer. However, in this time of increasing interest in the parameters of ovarian reserve, there are no national recommendations on the subject. This literature review provides an enlightened look at the rationale for performing an opportunistic salpingectomy.

OBJECTIVES

To evaluate the benefits and risks associated with opportunistic salpingectomy during surgery for a benign gynecological condition.

MATERIAL AND METHODS

We carried out a systematic review of the literature using the Pubmed/Medline search engine and the Cochrane database.

RESULTS

A total of 61 articles were selected from over 300 references. The protective impact against cancer, which is widely demonstrated in the literature, is proof of the benefit of this procedure. Furthermore, no increase in intraoperative morbidity has been noted. However, the clinical impact on the ovarian reserve remains uncertain (in particular the occurrence of early pre-menopausal symptoms during the perimenopausal period). Nonetheless, the socioeconomic analysis supports performing opportunistic salpingectomy.

CONCLUSION

Performing opportunistic salpingectomy does not appear to cause an increase in morbidity but the impact on ovarian function is uncertain. The fact that there is a proven benefit of such a procedure against cancer indicates that prior to any surgery a clear discussion should be held with the patient in which they should be fully informed.

An Alternate Diagnostic Algorithm for the Diagnosis of Intraepithelial Fallopian Tube Lesions

Intraepithelial fallopian tube neoplasia is thought to be a precursor lesion to high-grade serous carcinoma of the Müllerian adnexae, particularly in women with BRCA1 or BRCA2 mutations. This association has led to recommendations to assess fallopian tubes for intraepithelial atypia. However, the diagnostic reproducibility of a diagnosis of intraepithelial neoplasia is unclear. In this study, 2 gynecologic pathologists independently evaluated sections of fallopian tubes from a sample of women (N=198, 623 slides) undergoing salpingectomy. A total of 101 (54%) women were undergoing risk-reducing salpingo-oophorectomy. Pathologists were blinded to patient histories and prior diagnoses. Pathologists rendered one of three diagnoses for each slide: "negative for fallopian tube intraepithelial neoplasia (FTIN)," "indeterminate for FTIN," or "definite for FTIN." Cases that were considered by histology definite for FTIN or suspicious for FTIN were stained with p53 and Ki67. Pathologists agreed on the diagnosis of "definite for FTIN" 61.5% of the time. There was no agreement on any cases for the diagnosis of "indeterminate for FTIN." Fifteen "indeterminate for FTIN" and 12 "definite for FTIN" cases were stained with p53 and Ki67. Two of the "indeterminate" cases (13%) had p53-positive foci. Five of the "definite" cases had p53-positive foci. In 3 of the other 8 "definite" cases, there was obvious carcinoma present, but the carcinoma did not stain with p53, suggesting a possible null phenotype. We propose that immunostains should only be used to aid in the diagnosis of FTIN in cases with indeterminate histology. The use of p53 immunohistochemistry in cases that were considered "definite for FTIN" by histology was minimally helpful, and in fact often served to further confuse the diagnosis.

Fallopian Tube Epithelial Changes in Ovarian Serous Tumors Compared with Control Group: A Single-Center Study

BACKGROUND

Recent studies have hypothesized that distal end of fallopian tube is a possible origin of ovarian serous carcinoma. This study investigated histopathological changes in fallopian tube epithelium (FTE) of the patients with ovarian serous tumors compared with control group.

MATERIALS AND METHODS

In a prospective cross-sectional study, fallopian tubes (right and left) of 34 cases with ovarian serous tumors were collected from patients who underwent surgery in two major gynecological centers affiliated to Shiraz University of Medical Sciences, Shiraz, Iran (2012-2015). They are composed of 21 (61.8%) high-grade serous carcinomas (HGSCs), 5 (14.7%) borderline ones, and 8 (23.5%) benign serous tumors. As control group, fallopian tubes of 72 hystrectomy cases without ovarian tumor were added to the study. Both tubes of all of the cases were submitted entirely, according to the protocol of sectioning and extensively examining the fimbriated end. The results were statistically analyzed using SPSS-PC windows and Chi-square tests.

RESULTS

Significant differences were found between the cases and control group in tubal epithelial cell stratification (especially >3 cell layers thickness), atypia, mitosis, glandular complexity, tufting, and detached epithelial cells (P < 0.05). These findings particularly atypia and mitosis were more frequently seen in the ampulla and fimbriated end of high-grade ovarian serous carcinomas.

CONCLUSION

Our results showed that premalignant epithelial changes of the ampulla and the distal end of FTE were seen in some of the patients with ovarian HGSCs. Therefore, FTE could be one of the sources of ovarian serous carcinoma.

Gynaecological neoplasms in common familial syndromes (Lynch and HBOC)

Recognising hereditary predisposition in a cancer patient has implications both for the patient and the patient's kindred. For the latter, cascade germline testing can reassure those not-at-risk family members while carriers can be enrolled in cancer screening and prevention programs that are medically effective and economically sustainable for health care systems. Furthermore, in many of these syndromes, ramifications of molecular phenotypes are increasing, and it is now emerging that, in addition, they convey prognostic and predictive information. Although cancer predisposition syndromes are rare, these molecular phenotypes also occur as somatic events in sporadic cancer settings. The information obtained from these molecular phenotypes, regardless of germline or somatic origin, is being incorporated into clinical management in view of their manifold significance. Thus, increasingly, bespoke management of cancer patients involves testing for both germline and somatic mutations in tumours. Lynch syndrome and BRCA-1 and BRCA-2-associated hereditary breast and ovarian cancer are hereditary cancer syndromes frequently involving the gynaecological tract but tumours associated with similar molecular alterations may also occur sporadically. Thus, the molecular phenotype of mismatch repair deficiency, microsatellite instability or hypermutator phenotype may be attributable to germline or somatic events. Similarly, homologous recombination deficiency or 'BRCAness' in ovarian cancers may be syndromic or sporadic. While hereditary syndromes are well recognised, the prognostic and predictive implications of these molecular phenotypes have only recently been elucidated and these aspects will finally ensure that molecular screening may become standard of care. Thus, nowadays pathologists are asked to designate the molecular phenotype of these cancers and then determine whether it is due to hereditary or sporadic causes.

Cancer Risk-Reducing Opportunities in Gynecologic Surgery

This review article discusses cancer risk-reducing opportunities in gynecologic surgery. We cover strategies to reduce ovarian and uterine cancer risk by presenting general practice guidelines and expanding on the literature behind clinical decision points. We address populations of women at increased hereditary risk and those at population risk. We specifically discuss risk-reducing salpingo-oophorectomy, prophylactic salpingectomy with delayed oophorectomy, concomitant hysterectomy, opportunistic salpingectomy, bilateral tubal ligation, and hysterectomy. For clinical scenarios in which data are limited or conflicting, we detail the studies on which clinicians' decisions hinge to allow the reader to weigh the available evidence.

[What haemostatic technique should we use for opportunistic salpingectomy during benign laparoscopic hysterectomy?]

OBJECTIVE

To compare ovarian function before and after laparoscopic hysterectomy with bilateral salpingectomy for benign lesions with two different systems of haemostasis.

METHODS

In this prospective randomized study comparing two types of energy used for coagulation in bilateral salpingectomy (group A: bipolar electric energy, versus group B: ultrasonic advanced energy [Harmonic^®]), forty consecutive non-menopausal patients undergoing laparoscopic hysterectomy for benign lesions were included. Values of anti-Müllerian hormone (AMH), LH and FSH, antral follicle count (AFC) and ovarian vascularization on bilateral Doppler ultrasound, quality of life (questionnaire) were assessed preoperatively and at 1 and 3 months postoperatively.

RESULTS

Preliminary analysis showed shorter salpingectomy operating time (P<0.0001) and less bleeding (P<0.005) in group B. In group A, there was no statistical difference except a decrease in AFC at 1 and 3 months on the right ovary (P=0.04). In group B, AMH levels were significantly lower postoperatively at 3 months and LH levels were increased at 3 months (respectively P=0.02 et P=0.04). There was no statistical difference in the ultrasonographic data. Quality of life did not significantly differ in both groups.

CONCLUSION

Preliminary findings showed reduced AMH levels at 3months postoperatively in ultrasonic energy group whereas there was no significative menopausal symptoms. It seems important to continue this study in order to know the real effects of both energy systems on the ovarian function.

High-grade serous carcinoma of tubo-ovarian origin: recent developments

Extra-uterine high-grade serous carcinoma (HGSC) accounts for most of the morbidity and mortality associated with ovarian carcinoma, and is one of the leading causes of cancer death in women. Until recently our understanding of HGSC was very limited compared to other common cancers, and it has only been during the last 15 years that we have learned how to diagnose this ovarian carcinoma histotype accurately. Since then, however, there has been rapid progress, with identification of a precursor lesion in the fallopian tube, development of prevention strategies for both those with inherited susceptibility (hereditary breast and ovarian cancer syndrome) and without the syndrome, and elucidation of the molecular events important in oncogenesis. This molecular understanding has led to new treatment strategies for HGSC, with the promise of more to come in the near future. In this review we focus on these recent changes, including diagnostic criteria/differential diagnosis, primary site assignment, precursor lesions and the molecular pathology of HGSC.

Mucosal Proliferations in Completely Examined Fallopian Tubes Accompanying Ovarian Low-grade Serous Tumors: Neoplastic Precursor Lesions or Normal Variants of Benign Mucosa?

Malignant transformation of the fallopian tube mucosa, followed by exfoliation of malignant cells onto ovarian and/or peritoneal surfaces, has been implicated as the origin of most pelvic high-grade serous carcinoma. Whether a parallel pathway exists for pelvic low-grade serous tumors [ovarian serous borderline tumor (SBT) and low-grade serous carcinoma (LGSC)] remains to be fully elucidated. The literature is challenging to interpret due to variation in the diagnostic criteria and terminology for cytologically low-grade proliferations of the fallopian tube mucosa, as well as variation in fallopian tube specimen sampling. Recently, a candidate fallopian tube precursor to ovarian SBT, so-called papillary tubal hyperplasia, was described in advanced stage patients. The current study was designed to identify fallopian tube mucosal proliferations unique to patients with low-grade serous ovarian tumors (serous cystadenoma, SBT, LGSC) and to determine if they may represent precursors to the ovarian tumors. Fallopian tubes were thinly sliced and entirely examined microscopically, including all of the fimbriated and nonfimbriated portions of the tubes, from patients with ovarian serous cystadenoma (35), SBT (61), and LGSC (11) and from a control population of patients with ovarian mucinous cystadenoma (28), mature cystic teratoma (18) or uterine leiomyoma (14). The slides of the fallopian tubes were examined in randomized order, without knowledge of the clinical history or findings in the ovaries or other organs. Alterations of the mucosa of the fallopian tube were classified as type 1: nonpapillary proliferation of cytologically bland tubal epithelium exhibiting crowding, stratification, and/or tufting without papillary fibrovascular cores or as type 2: papillary alterations consisting of a fibrovascular core lined by a cytologically bland layer of tubal epithelium. A third abnormality, type 3, consisted of detached intraluminal papillae, buds, or nests of epithelium that cytologically resembled the epithelial component of SBT or LGSC. Mucosal proliferations were identified in subsets of all populations, including the control populations. Overall, type 1 proliferations were in 28% to 61% of all patients and type 2 alterations in 4% to 16%. There was no statistically significant difference in the incidence of type 1 or type 2 proliferations between the class of ovarian serous tumors (benign, SBT, LGSC), between early and advanced stage SBT, or between patients with any ovarian serous tumor and the control population of nonserous diagnoses. Type 3 alterations were only identified in patients with advanced stage SBT/LGSC and not in any early stage SBT or cystadenoma. These findings suggest that type 3 alterations floating in the fallopian tube lumen represent exfoliation of tumor cells from ovarian and/or peritoneal origin. Our study did not identify a mucosal-based proliferation of the fallopian tubes that was specific to ovarian low-grade serous tumors. Cytologically bland mucosal proliferations appear to be common in fallopian tubes from patients of all ages and unrelated to ovarian tumorigenesis. A consensus on diagnostic criteria and terminology for these types of proliferations is needed, as well as further study into their etiology, including possible association with hormonal environment.

Opportunistic salpingectomy during vaginal hysterectomy for a benign pathological condition

INTRODUCTION AND HYPOTHESIS

The objective was to evaluate the surgical feasibility of opportunistic salpingectomy or salpingo-oophorectomy during benign vaginal hysterectomy (HV) and the prevalence of occult tubal lesions.

METHODS

In this prospective study from 1 September 2013 to 1 November 2015, the prevalence of bilateral salpingectomy with or without ovariectomy and the prevalence of histopathological and immunohistochemical tubal abnormalities were assessed.

RESULTS

A total 115 patients were included. Bilateral salpingectomy was performed in 85 patients (73.92%; group A) and was technically impossible in 30 patients (26.08%; group B). Older patients (62.9 vs 57.5 years, p = 0.009), menopausal status (83.33% vs 62.35%, p = 0.03) and elevated BMI (27.58 vs 25.05 p = 0.03) were statistically associated with failure of salpingectomy. There was only one case of postoperative hemorrhage in group A. There was no difference with regard to intra- or postoperative complications, blood loss, and operating time between the two groups. Among the 67 fallopian tubes analyzed with a validated histopathological protocol, there were 8 (11.94%) immunohistochemical abnormalities with a "p53 signature."

CONCLUSIONS

With the recent demonstration of a tubal origin of most ovarian cancer, opportunistic salpingectomy could be a theoretically relevant prevention strategy. Bilateral salpingectomy could be performed during benign vaginal hysterectomy by experienced surgeons. The advantages and disadvantages of exclusive salpingectomy during pelvic floor surgery should be discussed with the patients.

Serous tubal intraepithelial neoplasia: the concept and its application

In recent years it has become clear that many extra-uterine (pelvic) high-grade serous carcinomas (serous carcinomas) are preceded by a precursor lesion in the distal fallopian tube. Precursors range from small self-limited 'p53 signatures' to expansile serous tubal intraepithelial neoplasms that include both serous tubal epithelial proliferations (or lesions) of uncertain significance and serous tubal intraepithelial carcinomas. These precursors can be considered from three perspectives. The first is biologic underpinnings, which are multifactorial, and include the intersection of DNA damage with Tp53 mutations and disturbances in transcriptional regulation that increase with age. The second perspective is the morphologic discovery and classification of intraepithelial neoplasms that are intercepted early in their natural history, either incidentally or in risk-reduction surgeries for germline mutations. For the practicing pathologist, as well as the investigators, a distinction between a primary intraepithelial neoplasm and an intramucosal carcinoma must be made to avoid misinterpreting (or underestimating) the significance of these proliferations. The third perspective is the application of this information to intervention, devising strategies that will actually lower the ovarian cancer death rate by opportunistic salpingectomy, widespread comprehensive genetic screening and early detection. Central to this issue are the questions of (1) whether some STICs are metastatic, (2) whether lower-grade epithelial proliferations can invade prior to evolving into intraepithelial carcinoma, or (3) metastasize and become malignant elsewhere ('precursor escape'). An important caveat is the persistent and unsettling reality that many high-grade serous carcinomas are not associated with an obvious point of initiation in the fallopian tube. The pathologist sits squarely in the midst of all of these issues, and has a pivotal role in managing expectations for stemming the death rate from this lethal disease.

Comparison of the Classical Method and SEE-FIM Protocol in Detecting Microscopic Lesions in Fallopian Tubes with Gynecological Lesions

Background

The objective of this study was to compare the classical method and Sectioning and Extensively Examining the Fimbriated End Protocol (SEE-FIM) in detecting microscopic lesions in fallopian tubes with gynecological lesions.

Methods

From a total of 1,118 cases, 582 with various parts of both fallopian tubes sampled in three-ring-shape sections and 536 sampled with the SEE-FIM protocol were included in this study. Pathological findings of cases with endometrial carcinoma, non-uterine pelvic malignant tumor, ovarian borderline tumors, premalignancy, and benign lesions were compared.

Results

We detected two tubal infiltrative carcinomas among 40 uterine endometrioid adenocarcinomas, 15 serous tubal intraepithelial carcinomas in 39 non-uterine pelvic serous high-grade carcinoma cases, seven papillary tubal hyperplasias in 13 serous borderline tumor cases, and 11 endometriotic foci and four adenomatoid tumors among all cases sampled with the SEE-FIM protocol. Using the classical method, we detected only one serous tubal intraepithelial carcinoma in 113 non-uterine pelvic serous high-grade carcinoma cases and two papillary tubal hyperplasia cases in 31 serous borderline tumors. We did not identify additional findings in 185 uterine endometrioid carcinoma cases, and neither endometriotic focus nor adenomatoid tumor was shown in other lesions by the classical method.

Conclusions

Benign, premalignant, and malignant lesions can possibly be missed using the classical method. The SEE-FIM protocol should be considered especially in cases of endometrial carcinoma, nonuterine pelvic serous cancers, or serous borderline ovarian tumors. For other lesions, at least a detailed examination of the fimbrial end should be undertaken.

[Current surgical practice of prophylactic and opportunistic salpingectomy in France]

OBJECTIVES

Since the recent evidence of a tubal origin of most ovarian cancers, opportunistic salpingectomy could be discussed as a prophylactic strategy in the general population and with hereditary predisposition. We aimed to survey French gynecological surgeons about their current surgical practice of prophylactic salpingectomy.

METHODS

An anonymous online survey was sent to French obstetrician-gynaecologists and gynecological surgeons. There were 13 questions about their current clinical practice and techniques of salpingectomy during a benign hysterectomy or as a tubal sterilization method, salpingectomy versus salpingo-oophorectomy in the population with genetic risk, salpingectomy in relationship with endometriosis and questions including histopathological considerations.

RESULTS

Among the 569 respondents, opportunistic salpingectomy was always performed between 42.48% and 43.44% during laparoscopic, laparoscopic-assisted vaginal or laparotomic hysterectomy and only 12.26% in case of vaginal route. In the genetic population, salpingo-oophorectomy was mainly performed. Tubal sterilization was often practiced by the hysteroscopic route. More than 90% of respondents didn't perform salpingectomy in case of endometriosis. There was not any specific tubal histopathological protocol in 71.54% of cases.

CONCLUSIONS

Salpingectomy may be a preventing strategy in the low- and high-risk population. The survey's responses show that salpingectomy seems to be a current practice during benign hysterectomy for more than 40% doctors. However, there is not any change with no more salpingectomy in the population with genetic risk, or in case of endometriosis or tubal sterilization.

Serous tubal intraepithelial carcinoma, chronic fallopian tube injury, and serous carcinoma development

Ovarian carcinoma is the deadliest gynecological malignancy. Previous studies have suggested that the fallopian tube may be the primary site for high-grade serous carcinoma. In prophylactic salpingo-oophorectomies from women with hereditary high risk for ovarian cancer, precursors can be assessed prior to onset and studied as a model for serous cancer precursor lesions. Epidemiologic studies indicate that carcinogenesis may be a result of chronic fallopian tube injury. The aims of this study were to (1) to examine the incidence of serous tubal intraepithelial carcinoma (STIC) in relation to other clinical parameters and (2) to evaluate whether chronic fallopian tube injury was related to cancer development. This study enrolled 101 women, comprising the following three groups: hereditary (n = 60), sporadic serous cancer (n = 18; endometrial cancers were excluded), and control (n = 23). The cases were histologically examined and clinical risk factors were collected. The histological changes were compared between different patients and correlated to clinical risk factors. STICs were identified primarily on the fallopian tube fimbria. The incidence of STIC was 3 % in the hereditary patients. In sporadic serous cancer cases, 61 % were associated with STIC and tubal carcinoma (p < 0.001). No differences in tubal injury or inflammation were seen when comparing the sporadic serous cancer group and the control group or within the hereditary group. STIC and invasive cancer were seen more often in the older patients than in the younger patients (p = 0.528). This small study, no correlation with chronic tubal injury or inflammation was identified.

In vitro and in vivo correlates of physiological and neoplastic human Fallopian tube stem cells

High-grade serous cancer (HGSC) progresses to advanced stages without symptoms and the 5-year survival rate is a dismal 30%. Recent studies of ovaries and Fallopian tubes in patients with BRCA1 or BRCA2 mutations have documented a pre-metastatic intramucosal neoplasm that is found almost exclusively in the Fallopian tube, termed 'serous tubal intraepithelial carcinoma' or STIC. Moreover, other proliferations, termed p53 signatures, secretory cell outgrowths (SCOUTs), and lower-grade serous tubal intraepithelial neoplasms (STINs) fall short of STIC but share similar alterations in expression, in keeping with an underpinning of genomic disturbances involved in, or occurring in parallel with, serous carcinogenesis. To gain insight into the cellular origins of this unique tubal pathway to high-grade serous cancer, we cloned and both immortalized and transformed Fallopian tube stem cells (FTSCs). We demonstrated that pedigrees of FTSCs were capable of multipotent differentiation and that the tumours derived from transformed FTSCs shared the histological and molecular features of HGSC. We also demonstrated that altered expression of some biomarkers seen in transformed FTSCs and HGSCs (stathmin, EZH2, CXCR4, CXCL12, and FOXM1) could be seen as well in immortalized cells and their in vivo counterparts SCOUTs and STINs. Thus, a whole-genome transcriptome analysis comparing FTSCs, immortalized FTSCs, and transformed FTSCs showed a clear molecular progression sequence that is recapitulated by the spectrum of accumulated perturbations characterizing the range of proliferations seen in vivo. Biomarkers unique to STIC relative to normal tubal epithelium provide a basis for novel detection approaches to early HGSC, but must be viewed critically given their potential expression in lesser proliferations. Perturbations shared by both immortalized and transformed FTSCs may provide unique early targets for prevention strategies. Central to these efforts has been the ability to clone and perpetuate multipotent FTSCs.

Ovary and fimbrial stem cells: biology, niche and cancer origins

The mammalian ovary is covered by a single-layered epithelium that undergoes rupture and remodelling following each ovulation. Although resident stem cells are presumed to be crucial for this cyclic regeneration, their identity and mode of action have been elusive. Surrogate stemness assays and in vivo fate-mapping studies using recently discovered stem cell markers have identified stem cell pools in the ovary and fimbria that ensure epithelial homeostasis. Recent findings provide insights into intrinsic mechanisms and local extrinsic cues that govern the function of ovarian and fimbrial stem cells. These discoveries have advanced our understanding of stem cell biology in the ovary and fimbria, and lay the foundations for evaluating the contribution of resident stem cells to the initiation and progression of human epithelial ovarian cancer.

[Prophylactic salpingectomy or salpingo-oophorectomy as an ovarian cancer prevention?]

A recent hypothesis has stated that many ovarian cancers (especially high-grade serous histotype) could arise from the distal part of the fallopian tube. On one hand we know that risk-reducing salpingo-oophorectomy is the most effective prevention for ovarian cancer among BRCA mutation carriers. On the other, oophorectomy increases the relative risk for cardiovascular, osteoporotic psychosexual and cognitive dysfunctions in premenopausal women. This raises the question whether bilateral salpingectomy could be an effective strategy in the prevention of ovarian cancer in case of hereditary predisposition and in the general population. Here we discuss origin of ovarian cancer in the light of the latest molecular studies and the relative risks and benefits of a strategy of exclusive salpingectomy in comparison with the classical adnexectomy.

Morphological and immunohistochemical pattern of tubo-ovarian dysplasia and serous tubal intraepithelial carcinoma

OBJECTIVE

Histopathological examination of material from prophylactic salpingo-oophorectomies performed in patients at genetic risk of ovarian cancer can reveal abnormalities interpreted as possible pre-cancerous "ovarian dysplasia" and tubal precursors lesions. We sought to study the morphological features and immunohistochemical expression patterns of neoplasia-associated markers in prophylactically removed ovaries and fallopian tubes (pBSO) in comparison with a group of serous tubal intraepithelial carcinoma (STIC) and non-cancerous controls.

STUDY DESIGN

Morphological features and immunohistochemical expression patterns of Ki-67 (for proliferation biomarker), p53 (key pathway of mullerian serous tumorogenesis), Bcl2 (anti-apoptotic), γH2AX (a double-strand breaks marker) and ALDH1 (a stem cell marker significantly associated with early-stage ovarian cancer) were blindly evaluated by two pathologists in 111 pBSO, 12 STICs and 116 non-cancerous salpingo-oophorectomies (control group) (nBSO).

RESULTS

Morphological ovarian and tubal dysplasia scores were significantly higher in the pBSO than in controls (respectively, 8.8 vs 3.12, p<0.0001, for ovaries and 6.54 vs 1.58, p<0.0001 for tubes). Increased γH2AX expression was observed in the pBSO and STICs compared with the controls whereas expression patterns of Ki67, p53 and bcl2 were low to moderate in the pBSO group. STICs overexpressed Ki67 and p53 while bcl2 expression was low; Interestingly, ALDH1 expression was low in non dysplastic epithelium, high in dysplasia and constantly low in STICs.

CONCLUSION

The morphological and immunohistochemical profile of tubo-ovarian dysplasia and STICs might be consistent with progression toward neoplastic transformation in the Serous Carcinogenesis Sequence. These changes may be pre-malignant and could represent an important phase in early neoplasia. ALDH1 activation in pBSO samples and its extinction in STICs should be considered as a target for prevention.

The PAX2-null immunophenotype defines multiple lineages with common expression signatures in benign and neoplastic oviductal epithelium

The oviducts contain high-grade serous cancer (HGSC) precursors (serous tubal intraepithelial neoplasia or STINs), which are γ-H2AX(p) - and TP53 mutation-positive. Although they express wild-type p53, secretory cell outgrowths (SCOUTs) are associated with older age and serous cancer; moreover, both STINs and SCOUTs share a loss of PAX2 expression (PAX2(n) ). We evaluated PAX2 expression in proliferating adult and embryonic oviductal cells, normal mucosa, SCOUTs, Walthard cell nests (WCNs), STINs, and HGSCs, and the expression of genes chosen empirically or from SCOUT expression arrays. Clones generated in vitro from embryonic gynaecological tract and adult Fallopian tube were Krt7(p) /PAX2(n) /EZH2(p) and underwent ciliated (PAX2(n) /EZH2(n) /FOXJ1(p) ) and basal (Krt7(n) /EZH2(n) /Krt5(p) ) differentiation. Similarly, non-ciliated cells in normal mucosa were PAX2(p) but became PAX2(n) in multi-layered epithelium undergoing ciliated or basal (WCN) cell differentiation. PAX2(n) SCOUTs fell into two groups: type 1 were secretory or secretory/ciliated with a 'tubal' phenotype and were ALDH1(n) and β-catenin(mem) (membraneous only). Type 2 displayed a columnar to pseudostratified (endometrioid) phenotype, with an EZH2(p) , ALDH1(p) , β-catenin(nc) (nuclear and cytoplasmic), stathmin(p) , LEF1(p) , RCN1(p) , and RUNX2(p) expression signature. STINs and HGSCs shared the type 1 immunophenotype of PAX2(n) , ALDH1(n) , β-catenin(mem) , but highly expressed EZH2(p) , LEF1(p) , RCN1(p) , and stathmin(p) . This study, for the first time, links PAX2(n) with proliferating fetal and adult oviductal cells undergoing basal and ciliated differentiation and shows that this expression state is maintained in SCOUTs, STINs, and HGSCs. All three entities can demonstrate a consistent perturbation of genes involved in potential tumour suppressor gene silencing (EZH2), transcriptional regulation (LEF1), regulation of differentiation (RUNX2), calcium binding (RCN1), and oncogenesis (stathmin). This shared expression signature between benign and neoplastic entities links normal progenitor cell expansion to abnormal and neoplastic outgrowth in the oviduct and exposes a common pathway that could be a target for early prevention.

A genetically engineered ovarian cancer mouse model based on fallopian tube transformation mimics human high-grade serous carcinoma development

Recent evidence suggests that ovarian high-grade serous carcinoma (HGSC) originates from the epithelium of the fallopian tube. However, most mouse models are based on the previous prevailing view that ovarian cancer develops from the transformation of the ovarian surface epithelium. Here, we report the extensive histological and molecular characterization of the mogp-TAg transgenic mouse, which expresses the SV40 large T-antigen (TAg) under the control of the mouse müllerian-specific Ovgp-1 promoter. Histological analysis of the fallopian tubes of mogp-TAg mice identified a variety of neoplastic lesions analogous to those described as precursors to ovarian HGSC. We identified areas of normal-appearing p53-positive epithelium that are similar to 'p53 signatures' in the human fallopian tube. More advanced proliferative lesions with nuclear atypia and epithelial stratification were also identified that were morphologically and immunohistochemically reminiscent of human serous tubal intraepithelial carcinoma (STIC), a potential precursor of ovarian HGSC. Beside these non-invasive precursor lesions, we also identified invasive adenocarcinoma in the ovaries of 56% of the mice. Microarray analysis revealed several genes differentially expressed between the fallopian tube of mogp-TAg and wild-type (WT) C57BL/6. One of these genes, Top2a, which encodes topoisomerase IIα, was shown by immunohistochemistry to be concurrently expressed with elevated p53 and was specifically elevated in mouse STICs but not in the surrounding tissues. TOP2A protein was also found elevated in human STICs, low-grade and high-grade serous carcinoma. The mouse model reported here displays a progression from normal tubal epithelium to invasive HGSC in the ovary, and therefore closely simulates the current emerging model of human ovarian HGSC pathogenesis. This mouse therefore has the potential to be a very useful new model for elucidating the mechanisms of serous ovarian tumourigenesis, as well as for developing novel approaches for the prevention, diagnosis and therapy of this disease.

The association of serous tubal intraepithelial carcinoma with gynecologic pathologies and its role in pelvic serous cancer

OBJECTIVES

Possible primary sites of pelvic serous cancers are, fallopian tubes, ovaries or peritoneum. Recent studies have revealed that a portion of these tumors originates from serous tubal intraepithelial carcinoma (STIC) at the distal end of fallopian tubes. In this study, the association of STIC with pelvic serous carcinomas and the pathologic parameters that indicate the tubes as the primary site were assessed.

METHODS

In total, 495 pairs of fallopian tubes obtained via total abdominal hysterectomy and bilateral salpingo-oophorectomy between 2011 and 2013 were examined according to SEE-FIM protocol. Hematoxylin and eosin-stained slides were examined by pathologists. Suspicious areas were immunostained with p53 and Ki-67 to diagnose STIC precisely.

RESULTS

Of the 495 cases, 110 cases were malignant. Among 34 cases of non-uterine serous carcinomas, 13 were diagnosed with STIC. STIC was located at the fimbrial end of the fallopian tubes in 12 cases. No STIC was identified in the gynecologic malignancies other than non-uterine serous pelvic carcinomas and benign gynecologic pathologies. Comparison of the ovarian and tubal cancer cases with and without STIC did not reveal a factor that helps to define the primary site. STIC was an important factor associated in a higher portion of the cases with bilateral ovarian cancer.

CONCLUSION

The role of STIC in carcinogenesis continues to be discussed as it is unknown whether STIC is the precursor lesion or just associates with the malignancies. Discovering the accurate precursor lesions and tumor carcinogenesis is essential to prevent these malignancies and to develop early diagnostic methods.

Müllerian precursor lesions in serous ovarian cancer patients: using the SEE-Fim and SEE-End protocol

Serous ovarian cancer is suggested to develop from epithelium embryologically derived from the Müllerian ducts. The aim of the current study is to thoroughly, analyze the epithelium derived from the Müllerian ducts (cervix, endometrium and fallopian tubes) in serous ovarian cancer patients. Sixty women diagnosed with serous ovarian carcinoma were included in this multicentre, observational study. Tissues were embedded completely for histological assessment, in accordance with the SEE-Fim and SEE-End protocol (Sectioning and Extensively Examining of the Fimbriated end; and-Endometrium), and prevalence of cervical, as well as endometrial and tubal pathology was analyzed. In 31 (52%) cases, a pathologic lesion was identified, and in 16 (27%) of these cases coexistence of pathologic lesions. In 1 case, severe dysplasia was found in the cervix, in 9 (15%) cases endometrial intraepithelial carcinoma, in 19 (32%) cases atypical hyperplasia, and in 23 (43%) cases serous tubal intraepithelial carcinoma. Serous tubal intraepithelial carcinoma was seen significantly more often concurrent with endometrial atypical hyperplasia or endometrial intraepithelial carcinoma than with benign endometrium (64 vs 28%; P=0.01). To conclude, histological assessment of epithelium derived from Müllerian ducts of serous ovarian cancer patients resulted in the identification of endometrial intraepithelial carcinoma, serous tubal intraepithelial carcinoma and/or endometrial atypical hyperplasia in more than half of cases. Coexistence of these pathologic lesions was common, and might represent an effect of field carcinogenesis or tumor implantation of migrating cells.

Mesenchymal gene program-expressing ovarian cancer spheroids exhibit enhanced mesothelial clearance

Metastatic dissemination of ovarian tumors involves the invasion of tumor cell clusters into the mesothelial cell lining of peritoneal cavity organs; however, the tumor-specific factors that allow ovarian cancer cells to spread are unclear. We used an in vitro assay that models the initial step of ovarian cancer metastasis, clearance of the mesothelial cell layer, to examine the clearance ability of a large panel of both established and primary ovarian tumor cells. Comparison of the gene and protein expression profiles of clearance-competent and clearance-incompetent cells revealed that mesenchymal genes are enriched in tumor populations that display strong clearance activity, while epithelial genes are enriched in those with weak or undetectable activity. Overexpression of transcription factors SNAI1, TWIST1, and ZEB1, which regulate the epithelial-to-mesenchymal transition (EMT), promoted mesothelial clearance in cell lines with weak activity, while knockdown of the EMT-regulatory transcription factors TWIST1 and ZEB1 attenuated mesothelial clearance in ovarian cancer cell lines with strong activity. These findings provide important insights into the mechanisms associated with metastatic progression of ovarian cancer and suggest that inhibiting pathways that drive mesenchymal programs may suppress tumor cell invasion of peritoneal tissues.

Recent concepts of ovarian carcinogenesis: type I and type II

Type I ovarian tumors, where precursor lesions in the ovary have clearly been described, include endometrioid, clear cell, mucinous, low grade serous, and transitional cell carcinomas, while type II tumors, where such lesions have not been described clearly and tumors may develop de novo from the tubal and/or ovarian surface epithelium, comprise high grade serous carcinomas, undifferentiated carcinomas, and carcinosarcomas. The carcinogenesis of endometrioid and clear cell carcinoma (CCC) arising from endometriotic cysts is significantly influenced by the free iron concentration, which is associated with cancer development through the induction of persistent oxidative stress. A subset of mucinous carcinomas develop in association with ovarian teratomas; however, the majority of these tumors do not harbor any teratomatous component. Other theories of their origin include mucinous metaplasia of surface epithelial inclusions, endometriosis, and Brenner tumors. Low grade serous carcinomas are thought to evolve in a stepwise fashion from benign serous cystadenoma to a serous borderline tumor (SBT). With regard to high grade serous carcinoma, the serous tubal intraepithelial carcinomas (STICs) of the junction of the fallopian tube epithelium with the mesothelium of the tubal serosa, termed the “tubal peritoneal junction” (TPJ), undergo malignant transformation due to their location, and metastasize to the nearby ovary and surrounding pelvic peritoneum. Other theories of their origin include the ovarian hilum cells.

Early preinvasive lesions in ovarian cancer

Faced with the catastrophic prognosis for ovarian cancer due to the fact that it is most often diagnosed late at the peritoneal carcinomatosis stage, screening and early detection could probably reduce the mortality rate. A better understanding of the molecular characteristics of the different ovarian cancer subtypes and their specific molecular signatures is indispensable prior to development of new screening strategies. We discuss here the early natural history of ovarian cancer and its origins.

Cyclin E1 deregulation occurs early in secretory cell transformation to promote formation of fallopian tube-derived high-grade serous ovarian cancers

The fallopian tube is now generally considered the dominant site of origin for high-grade serous ovarian carcinoma. However, the molecular pathogenesis of fallopian tube-derived serous carcinomas is poorly understood and there are few experimental studies examining the transformation of human fallopian tube cells. Prompted by recent genomic analyses that identified cyclin E1 (CCNE1) gene amplification as a candidate oncogenic driver in high-grade serous ovarian carcinoma, we evaluated the functional role of cyclin E1 in serous carcinogenesis. Cyclin E1 was expressed in early- and late-stage human tumor samples. In primary human fallopian tube secretory epithelial cells, cyclin E1 expression imparted malignant characteristics to untransformed cells if p53 was compromised, promoting an accumulation of DNA damage and altered transcription of DNA damage response genes related to DNA replication stress. Together, our findings corroborate the hypothesis that cyclin E1 dysregulation acts to drive malignant transformation in fallopian tube secretory cells that are the site of origin of high-grade serous ovarian carcinomas.

Human ovarian cancer stroma contains luteinized theca cells harboring tumor suppressor gene GT198 mutations

Ovarian cancer is a highly lethal gynecological cancer, and its causes remain to be understood. Using a recently identified tumor suppressor gene, GT198 (PSMC3IP), as a unique marker, we searched for the identity of GT198 mutant cells in ovarian cancer. GT198 has germ line mutations in familial and early onset breast and ovarian cancers and recurrent somatic mutations in sporadic fallopian tube cancers. GT198 protein has been shown as a steroid hormone receptor coregulator and also as a crucial factor in DNA repair. In this study, using GT198 as a marker for microdissection, we find that ovarian tumor stromal cells harboring GT198 mutations are present in various types of ovarian cancer including high and low grade serous, endometrioid, mucinous, clear cell, and granulosa cell carcinomas and in precursor lesions such as inclusion cysts. The mutant stromal cells consist of a luteinized theca cell lineage at various differentiation stages including CD133(+), CD44(+), and CD34(+) cells, although the vast majority of them are differentiated overexpressing steroidogenic enzyme CYP17, a theca cell-specific marker. In addition, wild type GT198 suppresses whereas mutant GT198 protein stimulates CYP17 expression. The chromatin-bound GT198 on the human CYP17 promoter is decreased by overexpressing mutant GT198 protein, implicating the loss of wild type suppression in mutant cells. Together, our results suggest that GT198 mutant luteinized theca cells overexpressing CYP17 are common in ovarian cancer stroma. Because first hit cancer gene mutations would specifically mark cancer-inducing cells, the identification of mutant luteinized theca cells may add crucial evidence in understanding the cause of human ovarian cancer.

Endosalpingiosis in peritoneal washings in women with benign gynecologic conditions: thirty-eight cases confirmed with paired box-8 immunohistochemical staining and correlation with surgical biopsy findings

BACKGROUND

To better define the cytomorphologic spectrum of endosalpingiosis in peritoneal washings (PWs) and thereby facilitate their distinction from well differentiated serous carcinoma, the authors examined PWs from women who underwent surgery and pathologic staging of lesions other than Mullerian malignancies and correlated the findings with surgical specimens.

METHODS

This was a retrospective review of medical records and PW specimens from 100 consecutive patients who had PWs coded as both "endosalpingiosis" and "negative for carcinoma" between 2002 and 2012. Thirty-eight of these patients had no gynecologic malignancies. Specimens had been prepared using cytocentrifugation and were stained using the Papanicolaou method. The cytologic findings evaluated were cell arrangement, number of cell groups per case, cellular atypia, and psammoma bodies. Smears also were assessed for paired box-8 (PAX8) immunostaining. The authors compared patients' staging biopsy findings with the findings from a review of the PWs.

RESULTS

PW specimens from 35 of 38 patients (92%) exhibited classic endosalpingiosis features: tubular or small branching papillary structures, some with psammoma bodies. Specimens from the 3 remaining patients displayed nonclassic features consistent with dislodged fallopian tube epithelium or endometriosis. From 2 to 20 clusters per slide and from 4 to 50 groups per case were identified. In a few cases, some cell clusters exhibited up to moderate cytologic atypia. Surgical findings included endometriosis, endosalpingiosis, both endometriosis and endosalpingiosis (12 patients; 31.6%), and a variety of unrelated pelvic lesions. All cases were PAX8-positive, confirming their Mullerian origin.

CONCLUSIONS

Endosalpingiosis in PWs can be diagnostically challenging. Awareness of intraoperative techniques and correlation with surgical biopsy findings are necessary to avoid a misdiagnosis of malignancy.

The Utility of Immunohistochemistry for Providing Genetic Information on Tumors

With advances in immunohistochemical technology and growing knowledge of the molecular genetics of tumors, immunohistochemistry is playing an increasingly important role in providing genetic information for tumors. Specific chromosomal translocations can be demonstrated through detection of the protein product of one of the genes involved in gene fusion (such as BCL2, cyclin D, and ALK). Some mutations can be detected by (1) aberrant localization of the protein product (such as β-catenin and nucleophosmin), (2) abnormal accumulation of the protein product as a result of stabilization of the protein (such as p53), and (3) mutation-specific antibodies directed against the mutant protein (such as isocitrate dehydrogenase gene R132H mutation, epidermal growth factor receptor gene L858R and exon 19 deletion mutations, and BRAF gene V600E mutation). Gene deletion or loss of function can be demonstrated by the loss of immunostaining for the protein product (such as mismatch repair proteins in microsatellite-unstable tumors, E-cadherin in lobular carcinoma of the breast, and INI1 in rhabdoid tumors, atypical teratoid/rhabdoid tumors, and epithelioid sarcomas). Gene amplification can be demonstrated by overexpression of the protein product (such as HER2 in breast and gastric cancers, and MDM2 or CDK4 in well-differentiated/dedifferentiated liposarcomas). Viruses associated with tumors can be demonstrated directly (such as Epstein-Barr virus latent membrane protein-1 in Hodgkin lymphomas, human herpesvirus 8 in Kaposi sarcomas, and Merkel cell polyomavirus in Merkel cell carcinomas) or by a surrogate marker (such as p16 in human papillomavirus infection). In this review, examples are given to illustrate the principles and pitfalls of these applications.

Precursors and pathogenesis of ovarian carcinoma

The ultimate goal of defining cancer specific precursors is to facilitate early detection and intervention before the development of invasive malignancy. Unlike other malignancies involving the female genital tract such as cervical or endometrial carcinomas, precursor lesions of ovarian carcinomas have not been well characterised, resulting in a failure to develop effective screening programs. Recent clinicopathological and molecular studies have provided new insight into the origin and pathogenesis of ovarian carcinomas. It has been shown that ovarian cancer is comprised of different tumour types differing not only in morphology, but also in pathogenesis, molecular alterations and clinical progression. A dualistic model of ovarian carcinogenesis has been proposed. Type I tumours which include low grade serous, low grade endometrioid, clear cell, mucinous carcinomas and Brenner tumours, are generally indolent and tend to be genetically stable, although clear cell carcinoma would probably belong to an intermediate category. They demonstrate a step-wise progression from a benign precursor such as a benign to borderline tumour or endometriosis and are characterised by genetic aberrations targeting specific cell signalling pathways. Type II tumours comprise high grade serous, high grade endometrioid, and undifferentiated carcinomas as well as malignant mixed mesodermal tumours. They are clinically aggressive and exhibit high genetic instability with frequent p53 mutations. Mounting evidence suggests that many high grade serous carcinomas originate from the epithelium of the distal fallopian tube, and that serous tubal intraepithelial carcinoma (STIC) represents the putative precursor of these neoplasms. Low grade serous carcinomas arise via transformation of benign and borderline serous tumours, thought to be derived from inclusion cysts originating from the ovarian surface or tubal epithelium. Recently it has been suggested that papillary tubal hyperplasia may be a putative precursor lesion for serous borderline tumours. Both endometrioid and clear cell carcinomas develop from endometriosis, via alterations affecting different genetic pathways. The origin of mucinous and transitional cell neoplasms is not well characterised, although new data suggest a possible origin from transitional cell nests present at the tubal-mesothelial junction. Likewise, the pathogenesis of carcinosarcomas is also not well established because of their rarity but there is accumulating evidence that the carcinomatous component determines the course of the disease and gives rise to the malignant mesenchymal component. This review discusses recent developments in the pathogenesis of ovarian carcinoma, with particular emphasis on the putative precursor lesions that give rise to the major histological subtypes. Recognition of these lesions is not only important in improving the understanding of ovarian carcinogenesis, but it will also influence our approach to prevent, detect and treat these tumours.

Long-term culture of primary porcine oviduct epithelial cells: validation of a comprehensive in vitro model for reproductive science

Recently, we established a protocol for the cultivation of primary porcine oviduct epithelial cells (POEC), which promoted tissue-like morphology for a prolonged culture period. The present study focuses on developing this model into a comprehensive, standardized culture system, as a candidate tool for reproductive toxicity testing and basic research. We cultivated POEC isolated from 25 animals in our culture system for both 3 and 6 weeks and systematically analyzed effects of medium conditioning, supplementation with standardized sera, and culture duration in both freshly isolated and cryopreserved cells. The differentiation status was evaluated via histomorphometry, transepithelial electrical resistance (TEER) measurement, and expression analyses. The culture system possessed high reproducibility, more than 95% of cultures achieved a fully differentiated phenotype. Cells recapitulated in vivo-like morphology and ultrastructure from 3 to 6 weeks. Cryopreservation of the cells prior to cultivation did not affect culture quality of POEC. Employment of conditioned medium ensured optimal promotion of POEC differentiation, and different standardized sera induced fully differentiated phenotypes. Consistent TEER establishment indicated the presence and maintenance of cell type-specific intercellular junctions. The functionality of POEC was proven by consistent mucin secretion and stable expression of selected markers over the whole culture duration. We conclude that POEC are suitable for experiments from 3 weeks up to at least 6 weeks of culture. Therefore, this culture system could be used for in vitro estrous cycle simulation and long-term investigation of toxic effects on oviduct epithelium.

Cancer stem cells, epithelial-mesenchymal transition, and drug resistance in high-grade ovarian serous carcinoma

Although epithelial ovarian cancer cells are eliminated by debulking surgery and chemotherapy during initial treatment, it is believed that only a subset of cancer cells, that is, cancer stem cells, may be an important source of tumor recurrence and drug resistance. This review highlights our current understanding of high-grade serous carcinoma, ovarian cancer stem cells, common methods for enrichment of ovarian cancer stem cells, mechanisms involved in drug resistance, and potential strategies for overcoming drug resistance, with associated potential controversies and pitfalls. We also review the potential relationship between epithelial-to-mesenchymal transition and cancer stem cells and how we can induce cancer cells to differentiate into benign stromal fibroblasts in response to certain chemotherapy drugs.

Early telomere shortening and genomic instability in tubo-ovarian preneoplastic lesions

PURPOSE

Genetic instability plays an important role in ovarian carcinogenesis. We investigated the level of telomere shortening and genomic instability in early and preinvasive stages of ovarian cancer, serous tubal intraepithelial carcinoma (STIC), and tubo-ovarian dysplasia (TOD).

EXPERIMENTAL DESIGN

Fifty-one TOD from prophylactic salpingo-oophorectomies with BRCA1 or 2 mutation, 12 STICs, 53 tubo-ovarian high-grade serous carcinoma, and 36 noncancerous controls were laser capture microdissected from formalin-fixed, paraffin-embedded sections, analyzed by comparative genomic hybridization (array CGH) and for telomere length (using quantitative real-time PCR based on the Cawthon's method). TOD and STICs were defined by morphologic scores and immunohistochemical expressions of p53, Ki67, and γH2AX.

RESULTS

TOD showed marked telomere shortening compared with noncancerous controls (P < 10(-7)). STICs had even shorter telomeres than TOD (P = 0.0008). Ovarian carcinoma had shorter telomeres than controls but longer than STICs and dysplasia. In TOD, telomeres were significantly shorter in those with BRCA1 mutation than in those with BRCA2 mutation (P = 0.005). In addition, γH2AX expression in TOD and STIC groups with short telomeres was significantly increased (P < 10(-7)). In dysplastic epithelium, we found subtle genomic alterations, in contrast to more important genomic imbalances in STICs. The total number of genetic alterations was the highest in ovarian cancers.

CONCLUSIONS

These findings suggest that genetic instability occurs in early stages of ovarian tumorigenesis. STICs and noninvasive dysplasia are likely an important step in early serous ovarian neoplasia.

Tu-be or not tu-be: that is the question… about serous ovarian carcinogenesis

Our understanding of the early natural history of epithelial ovarian carcinoma is limited by the access to early lesions as the disease is very often diagnosed at advanced stages. The incessant ovulation theory from the last century that indicated the ovary as the site for the initiation of high-grade serous cancers is contrary to the newly emerging idea that ovarian cancer could arise from the distal fallopian tube. In view of the recent pathological and molecular studies, we propose to discuss the genesis of high-grade serous ovarian cancer.