Ovarian epithelial dysplasia and prophylactic oophorectomy for genetic risk

[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.

Role of mesenchymal cells in the natural history of ovarian cancer: a review

Background

Ovarian cancer is the deadliest gynaecologic malignancy. Despite progresses in chemotherapy and ultra-radical surgeries, this locally metastatic disease presents a high rate of local recurrence advocating for the role of a peritoneal niche. For several years, it was believed that tumor initiation, progression and metastasis were merely due to the changes in the neoplastic cell population and the adjacent non-neoplastic tissues were regarded as bystanders. The importance of the tumor microenvironment and its cellular component emerged from studies on the histopathological sequence of changes at the interface between putative tumor cells and the surrounding non-neoplastic tissues during carcinogenesis.

Method

In this review we aimed to describe the pro-tumoral crosstalk between ovarian cancer and mesenchymal stem cells. A PubMed search was performed for articles published pertaining to mesenchymal stem cells and specific to ovarian cancer.

Results

Mesenchymal stem cells participate to an elaborate crosstalk through direct and paracrine interaction with ovarian cancer cells. They play a role at different stages of the disease: survival and peritoneal infiltration at early stage, proliferation in distant sites, chemoresistance and recurrence at later stage.

Conclusion

The dialogue between ovarian and mesenchymal stem cells induces the constitution of a pro-tumoral mesencrine niche. Understanding the dynamics of such interaction in a clinical setting might propose new therapeutic strategies.

Morphological and immunohistochemical study of ovarian and tubal dysplasia associated with tamoxifen

Ovarian epithelial dysplasia was initially described in material from prophylactic oophorectomies for BReast CAncer gene (BRCA) mutation. Similar histopathological abnormalities have been revealed after ovulation stimulation. Given that tamoxifen (TAM) has a clomid-like effect and is sometimes used to induce ovulation, we studied the morphological features and immunohistochemical expression patterns of neoplasia-associated markers in adnexectomies previously exposed to TAM for breast cancer. We blindly reviewed 173 histopathological slides of adnexectomies according to three groups – oophorectomies associated with TAM exposure (n=42), oophorectomies associated with clomiphene exposure (n=15) and a spontaneously fertile non cancerous control group (n=116). Morphological features (with an ovarian and tubal dysplasia scoring system) and immunohistochemical expression patterns of Ki-67, p53 and Aldehyde dehydrogenase 1 (ALDH1 is an enzyme significantly associated with earlystage ovarian cancer) were evaluated and correlated. Mean tubal dysplasia score was significantly higher in the TAM group and clomiphen group than in controls (respectively 7.8 vs 3.5, P<0.007 and 6.8 vs 3.5, P=0.008). There is no statistical difference for the ovarian score in TAM group in comparison with the control group whereas we found a significant score for clomiphen group (6.5, P=0.009). Increased ALDH1 expression was observed in the two exposed group whereas expression patterns of Ki67 and p53 were moderate. Interestingly, ALDH1 expression was low in non-dysplastic epithelium, high in dysplasia, and constantly low in the two carcinoma.

Furthemore, we confirm our previous results showing that ALDH1 may be a useful tissue biomarker in the subtle histopathological diagnosis of tubo-ovarian dysplasia.

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.

Sensitivity and resistance to treatment in the primary management of epithelial ovarian cancer

Ovarian carcinoma is the most lethal gynaecologic malignancy. Despite wide initial sensibility to chemotherapy especially to platinum-based regimens, the vast majority of patients with advanced stages of the disease develop recurrences and subsequent resistance to treatments. Ovarian cancer is actually considered as a heterogeneous disease at the clinical, histological and molecular level. In this review, the mechanisms of intrinsic sensitivity or resistance to treatment, especially to platinum-based chemotherapy are considered with particular reference to the significance of tumour heterogeneity. The molecular features involved in acquired resistance are reviewed and the current hypotheses are discussed. In particular, potential disruptions of the DNA reparation pathways are highlighted.

New hypothesis on pathogenesis of ovarian cancer lead to future tailored approaches

In the last decades, management of epithelial ovarian cancer (EOC) has been based on the staging system of the International Federation of Gynecology and Obstetrics (FIGO), and different classifications have been proposed for EOC that take account of grade of differentiation, histological subtype, and clinical features. However, despite taxonomic efforts, EOC appears to be not a unique disease; its subtypes differ for epidemiological and genetic risk factors, precursor lesions, patterns of spread, response to chemotherapy, and prognosis. Nevertheless, carboplatin plus paclitaxel combination represents the only standard treatment in adjuvant and advanced settings. This paper summarizes theories about the classification and origin of EOC and classical and new prognostic factors. It presents data about standard treatment and novel agents. We speculate about the possibility to create tailored therapy based on specific mutations in ovarian cancer and to personalize prevention.

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.

Tubo-ovarian dysplasia in relationship with ovulation induction in rats

OBJECTIVE

To assess tubo-ovarian dysplasia via morphologic and immunohistochemical study of rats exposed to ovulation stimulation protocols.

DESIGN

Animal experimental study.

SETTING

Academic research hospital.

ANIMAL(S)

72 female Wistar rats divided into three groups.

INTERVENTION(S)

Stimulation protocols using follicle-stimulating hormone (FSH) or clomiphene citrate for 3, 6, or 12 cycles, after which the animals were killed.

MAIN OUTCOME MEASURE(S)

Ovarian and tubal dysplasia score and immunohistochemical assessment using p53 and Ki67.

RESULT(S)

The ovarian dysplasia score was statistically significantly higher after 12 stimulation cycles in the groups receiving FSH (group B) or clomiphene citrate (group C) compared with control (group A). The tubal dysplasia score was statistically significantly increased after only three stimulation cycles in groups B and C. The Ki67 proliferation marker was statistically significantly expressed in the ovaries from group C, and in the fallopian tubes from groups B and C. P53 was constantly low in all three groups.

CONCLUSION(S)

Ovulation stimulation may induce tubal and ovarian histopathologic and immunohistochemical abnormalities with a dose effect. The role of the fallopian tubes and their interaction with the ovaries require further study.

Surgical implications of the potential new tubal pathway for ovarian carcinogenesis

Since 2001, many studies by different investigators have demonstrated that the fallopian tube might be at the origin of most high-grade ovarian and peritoneal serous carcinomas. Simple changes in surgical practice (ie, prophylactic bilateral salpingectomy instead of salpingo-oophorectomy) could have significant implications for death from ovarian cancer and, on the other hand, for the morbidity caused by ovariectomy (surgical menopause). In this review, we describe the new tubal carcinogenic sequence, the advantages and disadvantages of exclusive use of salpingectomy in the general population, and in cases of hereditary predisposition to ovarian cancer such as for carriers of BRCA mutation.

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.

[Don't forget fallopian tubes! A morphologic and immunohistochemical study about Fallopian tubes with genetic risk (BRCA mutation)]

OBJECTIVES

The objective of this study was to describe morphologic and immunohistochemical features of precursor tubal lesions in prophylactically removed Fallopian tubes.

PATIENTS AND METHODS

Hundred and forty-seven bilateral salpingectomies (genetic predisposition or group A: n=57; and control group or group B: n=90) were reviewed by two pathologists blinded to clinical data. Seven epithelial cytological and architectural features were studied to compare the degree of tubal epithelial abnormalities between the two groups. Immunohistochemical expression patterns of Ki67 and p53 were also evaluated.

RESULTS

Serous tubal intraepithelial lesions (STIL) have been identified in group A with stronger expression for Ki67 and p53 (especially in BRCA 1 group) than in group B.

DISCUSSION AND CONCLUSION

The current results show the importance of salpingo-oophrectomy in BRCA mutation carriers and the complete histopathological sampling of the Fallopian tubes.

Molecular pathogenesis and extraovarian origin of epithelial ovarian cancer--shifting the paradigm

Recent morphologic, immunohistochemical, and molecular genetic studies have led to the development of a new paradigm for the pathogenesis and origin of epithelial ovarian cancer based on a dualistic model of carcinogenesis that divides epithelial ovarian cancer into 2 broad categories designated types I and II. Type I tumors comprise low-grade serous, low-grade endometrioid, clear cell and mucinous carcinomas, and Brenner tumors. They are generally indolent, present in stage I (tumor confined to the ovary), and are characterized by specific mutations, including KRAS, BRAF, ERBB2, CTNNB1, PTEN, PIK3CA, ARID1A, and PPP2R1A, which target specific cell signaling pathways. Type I tumors rarely harbor TP53 mutations and are relatively stable genetically. Type II tumors comprise high-grade serous, high-grade endometrioid, malignant mixed mesodermal tumors (carcinosarcomas), and undifferentiated carcinomas. They are aggressive, present in advanced stage, and have a very high frequency of TP53 mutations but rarely harbor the mutations detected in type I tumors. In addition, type II tumors have molecular alterations that perturb expression of BRCA either by mutation of the gene or by promoter methylation. A hallmark of these tumors is that they are genetically highly unstable. Recent studies strongly suggest that fallopian tube epithelium (benign or malignant) that implants on the ovary is the source of low-grade and high-grade serous carcinoma rather than the ovarian surface epithelium as previously believed. Similarly, it is widely accepted that endometriosis is the precursor of endometrioid and clear cell carcinomas and, as endometriosis, is thought to develop from retrograde menstruation; these tumors can also be regarded as involving the ovary secondarily. The origin of mucinous and transitional cell (Brenner) tumors is still not well established, although recent data suggest a possible origin from transitional epithelial nests located in paraovarian locations at the tuboperitoneal junction. Thus, it now appears that type I and type II ovarian tumors develop independently along different molecular pathways and that both types develop outside the ovary and involve it secondarily. If this concept is confirmed, it leads to the conclusion that the only true primary ovarian neoplasms are gonadal stromal and germ cell tumors analogous to testicular tumors. This new paradigm of ovarian carcinogenesis has important clinical implications. By shifting the early events of ovarian carcinogenesis to the fallopian tube and endometrium instead of the ovary, prevention approaches, for example, salpingectomy with ovarian conservation, may play an important role in reducing the burden of ovarian cancer while preserving hormonal function and fertility.

[Ovarian epithelial dysplasia: Description of a dysplasia scoring scheme]

INTRODUCTION

Precancerous ovarian epithelial dysplasia was first described after prophylactic oophorectomy (OP) for genetic risk (BRCA mutation) or because of a strong family history of ovarian and/or breast cancer. The objective of this study was to describe histopathological features of ovarian dysplasia and to propose a dysplasia scoring sheme with a cut-off.

PATIENTS AND METHOD

One hundred and twenty-five bilateral oophorectomies (genetic predisposition: n=35 and control group: n=90) were reviewed by two pathologists blinded to clinical data. Eleven epithelial cytological and architectural features were studied and an ovarian dysplasia score was defined to compare the degree of ovarian epithelial abnormalities between the two groups.

RESULTS

Mean ovarian dysplasia score was significantly higher in prophylactic oophorectomy group than in control group (9.0 versus 3.5, P<0.001). Dysplasia was more severe in OP with BRCA mutation than in OP without (11.6 in BRCA 1; 7.6 in BCRA 2; 7.1 in family history). The cut off for dysplasia was 8 with a sensitivity of 60% and a specificity of 93.3%.

CONCLUSION

The increased dysplasia score in OP and the gradation in dysplastic severity in OP with proven BRCA mutations may suggest that ovarian dysplasia could be a pre-malignant non invasive histopathological lesion. The 11 cytological and architectural features in the dysplasia scoring sheme could be a useful tool to study ovarian dysplasia.