p53 signature and serous tubal in-situ carcinoma in cases of primary tubal and peritoneal carcinomas and serous borderline tumors of the ovary

Consensus based recommendations for the diagnosis of serous tubal intraepithelial carcinoma: an international Delphi study

AIM

Reliably diagnosing or safely excluding serous tubal intraepithelial carcinoma (STIC), a precursor lesion of tubo-ovarian high-grade serous carcinoma (HGSC), is crucial for individual patient care, for better understanding the oncogenesis of HGSC, and for safely investigating novel strategies to prevent tubo-ovarian carcinoma. To optimize STIC diagnosis and increase its reproducibility, we set up a three-round Delphi study.

METHODS AND RESULTS

In round 1, an international expert panel of 34 gynecologic pathologists, from 11 countries, was assembled to provide input regarding STIC diagnosis, which was used to develop a set of statements. In round 2, the panel rated their level of agreement with those statements on a 9-point Likert scale. In round 3, statements without previous consensus were rated again by the panel while anonymously disclosing the responses of the other panel members. Finally, each expert was asked to approve or disapprove the complete set of consensus statements. The panel indicated their level of agreement with 64 statements. A total of 27 statements (42%) reached consensus after three rounds. These statements reflect the entire diagnostic work-up for pathologists, regarding processing and macroscopy (three statements); microscopy (eight statements); immunohistochemistry (nine statements); interpretation and reporting (four statements); and miscellaneous (three statements). The final set of consensus statements was approved by 85%.

CONCLUSION

This study provides an overview of current clinical practice regarding STIC diagnosis amongst expert gynecopathologists. The experts' consensus statements form the basis for a set of recommendations, which may help towards more consistent STIC diagnosis.

Recommendations for diagnosing STIC: a systematic review and meta-analysis

Our understanding of the oncogenesis of high-grade serous cancer of the ovary and its precursor lesions, such as serous tubal intraepithelial carcinoma (STIC), has significantly increased over the last decades. Adequate and reproducible diagnosis of these precursor lesions is important. Diagnosing STIC can have prognostic consequences and is an absolute requirement for safely offering alternative risk reducing strategies, such as risk reducing salpingectomy with delayed oophorectomy. However, diagnosing STIC is a challenging task, possessing only moderate reproducibility. In this review and meta-analysis, we look at how pathologists come to a diagnosis of STIC. We performed a literature search identifying 39 studies on risk reducing salpingo-oophorectomy in women with a known BRCA1/2 PV, collectively reporting on 6833 patients. We found a pooled estimated proportion of STIC of 2.8% (95% CI, 2.0-3.7). We focused on reported grossing protocols, morphological criteria, level of pathologist training, and the use of immunohistochemistry. The most commonly mentioned morphological characteristics of STIC are (1) loss of cell polarity, (2) nuclear pleomorphism, (3) high nuclear to cytoplasmic ratio, (4) mitotic activity, (5) pseudostratification, and (6) prominent nucleoli. The difference in reported incidence of STIC between studies who totally embedded all specimens and those who did not was 3.2% (95% CI, 2.3-4.2) versus 1.7% (95% CI, 0.0-6.2) (p 0.24). We provide an overview of diagnostic features and present a framework for arriving at an adequate diagnosis, consisting of the use of the SEE-FIM grossing protocol, evaluation by a subspecialized gynecopathologist, rational use of immunohistochemical staining, and obtaining a second opinion from a colleague.

Progestin Significantly Inhibits Carcinogenesis in the Mogp-TAg Transgenic Mouse Model of Fallopian Tube Cancer

Recent studies suggest that the fallopian tube epithelium (FTE) harbors the precursor for high grade ovarian cancer, creating opportunities for targeting the FTE for ovarian cancer prevention. Preclinical evidence supports progestins as ovarian cancer preventives, but the effect of progestins on the FTE is not well characterized. The murine oviduct-specific glycoprotein promotor-driven simian virus 40 large T-Antigen (mogp-TAg) transgenic mouse model develops neoplastic lesions in the fallopian tube (FT) in a manner similar to that described in human fallopian and ovarian cancer. In this study, we investigated the inhibitory effects of the progestin Depo-medroxyprogesterone acetate (DMPA) on FT carcinogenesis following treatment for 3 and 7 weeks in 5-week-old mogp-TAg mice. Overall, compared to vehicle-treated mice, the FT of DMPA-treated mice was significantly smaller (p<0.0005), accumulated fewer p53-positive cells, had normal distribution of ciliated cells, less nuclear pleomorphism and epithelial tufting, and had a significantly lower proliferative index (p=0.001). Accumulation of p53 signatures and serous tubal intraepithelial carcinomas (STICs) in the FT was significantly reduced in the DMPA (p<0.0005) treatment group. Moreover, the FT of the DMPA-treated mice developed significantly less adenocarcinoma compared to vehicle (p<0.005) at both treatment time points. DMPA treatment significantly induced cleaved caspase-3 (p<0.0005) in the FTE compared to vehicle suggesting that apoptosis is involved in DMPA-related clearance of abnormal cells from the FT. These data demonstrate that DMPA targets early events in FT carcinogenesis by clearing genetically damaged cells, leading to marked reduction in adenocarcinoma, supporting progestins as chemopreventives for FT and ovarian cancer.

Most Commonly Mutated Genes in High-Grade Serous Ovarian Carcinoma Are Nonessential for Ovarian Surface Epithelial Stem Cell Transformation

High-grade serous ovarian carcinoma (HGSOC) is the fifth leading cause of cancer-related deaths of women in the United States. Disease-associated mutations have been identified by the Cancer Genome Atlas Research Network. However, aside from mutations in TP53 or the RB1 pathway that are common in HGSOC, the contributions of mutation combinations are unclear. Here, we report CRISPR mutagenesis of 20 putative HGSOC driver genes to identify combinatorial disruptions of genes that transform either ovarian surface epithelium stem cells (OSE-SCs) or non-stem cells (OSE-NSs). Our results support the OSE-SC theory of HGSOC initiation and suggest that most commonly mutated genes in HGSOC have no effect on OSE-SC transformation initiation. Our results indicate that disruption of TP53 and PTEN, combined with RB1 disruption, constitutes a core set of mutations driving efficient transformation in vitro. The combined data may contribute to more accurate modeling of HGSOC development.

Increase of fallopian tube and decrease of ovarian carcinoma: fact or fake?

PURPOSE

Accurate disease classification is fundamental for the selection of the treatment approach, prognostication, selection of clinical trials and for research purposes in routine clinical practice. Extrauterine high-grade serous carcinoma (HG-SC) may arise from the ovary, the fallopian tube and rarely from the peritoneal surface epithelium. Regardless of its origin, the vast majority of patients with HG-SC share clinical symptoms, present with advanced stage disease and suffer from a poor prognosis. Recent data suggest that there is an increasing incidence of HG-SC arising from the fallopian tube.

METHODS

Data from the Clinical Cancer Registry of Leipzig of surgically treated non-uterine pelvic carcinomas were analyzed regarding their sites of origin. Depending on the histology, cases were separated into high-grade serous and non-high-grade serous tumors. Based on different approaches in the assessment of the site of origin, three distinct time periods were defined. The frequency of the specific sites of origin was compared to the different time periods and histologic subtypes.

RESULTS

The majority of cases (57.9%; 279/482) were high-grade serous carcinomas, 42.1% of the cases presented with endometrioid, clear cell or mucinous histology. Overall, a 1.7-fold decrease of carcinomas with ovarian origin, paralleled by a 10.3-fold increase of tubal carcinomas was noted between 2000 and 2019. Based on the histopathological subtype, there was a 2.1-fold decrease of ovarian and a 7.1-fold increase of tubal carcinomas in patients with HG-SC. In non-high-grade serous tumors, the frequency of the different sites of origin did not change. 83.7% of tumors with non-high-grade serous histology originated from the ovary, whereas 86.8% of the carcinomas with tubal origin were of high-grade serous histology.

CONCLUSION

The present and published data of non-uterine pelvic cancers may suggest an increase of tubal and decrease of ovarian carcinomas. However, there is rising morphologic and molecular evidence that non-uterine HG-SC actually arise from the fallopian tubes via its precursor STIC instead of from the ovary. This evidence has had an impact on the handling and reporting of non-uterine surgical specimens and its definition of the site assessment. In conclusion, the increasing frequency of tubal carcinomas and the associated decrease in ovarian cancer appears to be due to the reclassification of tumors previously classified as ovarian and greater emphasis on examining the resection specimens of non-uterine pelvic carcinomas.

Specialist oncological surgery for removal of the ovaries and fallopian tubes in BRCA1 and BRCA2 pathogenic variant carriers may reduce primary peritoneal cancer risk to very low levels

Risk‐reducing bilateral salpingo‐oophorectomy (RRBSO) is highly effective for the prevention of high‐grade serous ovarian cancer (HGSOC) in BRCA1/2 pathogenic variant carriers (PVCs), but does not completely eliminate future risk of primary peritoneal cancer (PPC). The requirement to completely remove fallopian tubes at RRBSO and carefully exclude occult cancer/serous tubal intraepithelial carcinoma (STIC) lesions may not have been appreciated historically. We calculated rates of HGSOC and PPC in confirmed BRCA1/2 PVCs registered on the regional database in those who did (cases) and did not (controls) undergo RRBSO after genetic testing. Expected annual rates of ovarian/peritoneal cancer were 1% for BRCA1 ≥ 35 years and 0.5% for BRCA2 ≥ 45 years. Follow‐up before 35/45 years was “risk free” and lead time excluded RRBSO <35 years and <45 years for BRCA1 and BRCA2, respectively. Women were followed from personal mutation report (controls) or RRBSO (cases) to death, ovarian/peritoneal cancer or last follow‐up, whichever was sooner. In total, 891 cases (BRCA1 = 468, BRCA2 = 423) and 1302 controls had follow‐up ≥35 years (BRCA1 = 736) and ≥45 years (BRCA2 = 566), respectively, over a total of 7261.1 risk eligible years (mean = 8.15 years). Twenty‐one occult ovarian cancers were found at RRBSO (2.4%), 16 at stage 1. Post RRBSO, 56.97 ovarian/peritoneal cancers were expected but only 3 were observed (HR = 0.053; 95% CI = 0.013‐0.14), with combined Kaplan‐Meier analysis HR = 0.029 (95% CI = 0.009‐0.100, P < .001). Risk reduction was greater in specialist (HR = 0.03; 95% CI = 0.001‐0.13) compared to non‐specialist centres (HR = 0.11; 95% CI = 0.02‐0.37) (P = .07). In controls, 23.35 ovarian/peritoneal cancers were expected with 32 observed (HR = 1.37; 95% CI = 0.95‐1.91). RRBSO <35/<45 years reduces the risk of ovarian/peritoneal cancer by 95% in BRCA1/2 PVCs and may be greater in specialist centres.

What's new?

Women who carry genetic variants in BRCA1/2 that are linked to high‐grade serous ovarian cancer are advised to undergo risk‐reducing prophylactic bilateral salpingo‐oophorectomy (RRBSO). RRBSO, however, is associated with a significant residual risk of primary peritoneal cancer (PPC). Here, the rate of PPC following prophylactic surgery for high‐grade serous ovarian cancer was investigated among 2,193 BRCA1/2 mutation carriers who had undergone RRBSO. Estimates indicate that prophylactic surgery reduced the overall risk of PPC by 95 percent, a far greater reduction than previously described. Residual risk was lowest when RRBSO was carried out at specialist centers compared to non‐specialist centers.

Expresión de p53 en ovario y trompa uterina de tumores malignos epiteliales primarios del ovario

Introducción: la mutación en el gen TP53 se ha asociado con la oncogénesis de los tumores de ovario tipo II. Se ha propuesto que las mutaciones de p53 se inician en las células de la trompa uterina y después migran al ovario. El objetivo de este estudio es establecer la frecuencia de la expresión de p53 en ovario y trompa uterina en carcinoma epitelial primario de ovario. Materiales y métodos: estudio de corte transversal en tumores primarios epiteliales de ovario. Se evaluó la expresión de p53 por inmunohistoquímica en el ovario y en las trompas uterinas. Resultados: se incluyeron 45 pacientes con edad media de 55 años. Se estudiaron 24 casos de carcinomas serosos, 6 endometrioides, 5 mixtos, 3 de células claras, 3 carcinosarcomas, 2 carcinomas mucinosos y 2 indiferenciados. Se observó positividad fuerte y difusa en 68% de los tumores tipo II. En 52% hubo positividad en trompa uterina y ovario, 92% con compromiso bilateral. En 3 de estos casos se reconoció carcinoma intraepitelial tubárico con positividad de p53 en el área tumoral, no tumoral y en el carcinoma seroso. Conclusión: como se ha observado en estudios previos, el gen TP53 está involucrado en la oncogénesis de los tumores tipo II y se ha demostrado que existe una relación entre una mutación inicial de p53, seguida por STIL, STIC, evolucionando a un carcinoma seroso de ovario.

Mutant p53 regulates LPA signaling through lysophosphatidic acid phosphatase type 6

Emerging evidence has indicated that high-grade serous ovarian cancer (HGSOC) originates in the fallopian tube, where the earliest known genetic lesion is the mutation of TP53. In addition to such genetic changes, HGSOC is characterized by altered metabolism, including the production of oncogenic lipids such as lysophosphatidic acid (LPA). To understand the crosstalk between TP53 mutations and LPA signaling, we utilized primary fallopian tube epithelial cells (FTEC) engineered to overexpress mutant p53. We found that gain-of-function (GOF) p53 mutations downregulated the LPA-degrading enzyme lysophosphatidic acid phosphatase type 6 (ACP6), leading to upregulation of focal adhesion signaling in an LPA-dependent manner. Although highly expressed in normal fallopian tube epithelium, ACP6 expression was significantly reduced in ovarian cancer tumors and early in situ lesions. Downregulation of ACP6 in ovarian cancer cells was necessary and sufficient to support HGSOC proliferation, adhesion, migration, and invasion. Using mouse models of metastasis, we established that attenuation of ACP6 expression was associated with increased tumor burden. Conversely, overexpression of ACP6 suppressed invasive behavior. These data identify an involvement of oncogenic p53 mutations in LPA signaling and HGSOC progression through regulation of ACP6 expression.

Risk-reducing bilateral salpingo-oophorectomy in women with BRCA1 or BRCA2 mutations

BACKGROUND

The presence of deleterious mutations in breast cancer 1 gene (BRCA1) or breast cancer 2 gene (BRCA2) significantly increases the risk of developing some cancers, such as breast and high-grade serous cancer (HGSC) of ovarian, tubal and peritoneal origin. Risk-reducing salpingo-oophorectomy (RRSO) is usually recommended to BRCA1 or BRCA2 carriers after completion of childbearing. Despite prior systematic reviews and meta-analyses on the role of RRSO in reducing the mortality and incidence of breast, HGSC and other cancers, RRSO is still an area of debate and it is unclear whether RRSO differs in effectiveness by type of mutation carried.

OBJECTIVES

To assess the benefits and harms of RRSO in women with BRCA1 or BRCA2 mutations.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 7) in The Cochrane Library, MEDLINE Ovid, Embase Ovid and trial registries, with no language restrictions up to July 2017. We handsearched abstracts of scientific meetings and other relevant publications.

SELECTION CRITERIA

We included non-randomised trials (NRS), prospective and retrospective cohort studies, and case series that used statistical adjustment for baseline case mix using multivariable analyses comparing RRSO versus no RRSO in women without a previous or coexisting breast, ovarian or fallopian tube malignancy, in women with or without hysterectomy, and in women with a risk-reducing mastectomy (RRM) before, with or after RRSO.

DATA COLLECTION AND ANALYSIS

We extracted data and performed meta-analyses of hazard ratios (HR) for time-to-event variables and risk ratios (RR) for dichotomous outcomes, with 95% confidence intervals (CI). To assess bias in the studies, we used the ROBINS-I 'Risk of bias' assessment tool. We quantified inconsistency between studies by estimating the I² statistic. We used random-effects models to calculate pooled effect estimates.

MAIN RESULTS

We included 10 cohort studies, comprising 8087 participants (2936 (36%) surgical participants and 5151 (64%) control participants who were BRCA1 or BRCA2 mutation carriers. All the studies compared RRSO with or without RRM versus no RRSO (surveillance). The certainty of evidence by GRADE assessment was very low due to serious risk of bias. Nine studies, including 7927 women, were included in the meta-analyses. The median follow-up period ranged from 0.5 to 27.4 years.

MAIN OUTCOMES

overall survival was longer with RRSO compared with no RRSO (HR 0.32, 95% CI 0.19 to 0.54; P < 0.001; 3 studies, 2548 women; very low-certainty evidence). HGSC cancer mortality (HR 0.06, 95% CI 0.02 to 0.17; I² = 69%; P < 0.0001; 3 studies, 2534 women; very low-certainty evidence) and breast cancer mortality (HR 0.58, 95% CI 0.39 to 0.88; I² = 65%; P = 0.009; 7 studies, 7198 women; very low-certainty evidence) were lower with RRSO compared with no RRSO. None of the studies reported bone fracture incidence. There was a difference in favour of RRSO compared with no RRSO in terms of ovarian cancer risk perception quality of life (MD 15.40, 95% CI 8.76 to 22.04; P < 0.00001; 1 study; very low-certainty evidence). None of the studies reported adverse events.Subgroup analyses for main outcomes: meta-analysis showed an increase in overall survival among women who had RRSO versus women without RRSO who were BRCA1 mutation carriers (HR 0.30, 95% CI 0.17 to 0.52; P < 0001; I² = 23%; 3 studies; very low-certainty evidence) and BRCA2 mutation carriers (HR 0.44, 95% CI 0.23 to 0.85; P = 0.01; I² = 0%; 2 studies; very low-certainty evidence). The meta-analysis showed a decrease in HGSC cancer mortality among women with RRSO versus no RRSO who were BRCA1 mutation carriers (HR 0.10, 95% CI 0.02 to 0.41; I² = 54%; P = 0.001; 2 studies; very low-certainty evidence), but uncertain for BRCA2 mutation carriers due to low frequency of HGSC cancer deaths in BRCA2 mutation carriers. There was a decrease in breast cancer mortality among women with RRSO versus no RRSO who were BRCA1 mutation carriers (HR 0.45, 95% CI 0.30 to 0.67; I² = 0%; P < 0.0001; 4 studies; very low-certainty evidence), but not for BRCA2 mutation carriers (HR 0.88, 95% CI 0.42 to 1.87; I² = 63%; P = 0.75; 3 studies; very low-certainty evidence). One study showed a difference in favour of RRSO versus no RRSO in improving quality of life for ovarian cancer risk perception in women who were BRCA1 mutation carriers (MD 10.70, 95% CI 2.45 to 18.95; P = 0.01; 98 women; very low-certainty evidence) and BRCA2 mutation carriers (MD 13.00, 95% CI 3.59 to 22.41; P = 0.007; very low-certainty evidence). Data from one study showed a difference in favour of RRSO and RRM versus no RRSO in increasing overall survival (HR 0.14, 95% CI 0.02 to 0.98; P = 0.0001; I² = 0%; low-certainty evidence), but no difference for breast cancer mortality (HR 0.78, 95% CI 0.51 to 1.19; P = 0.25; very low-certainty evidence). The risk estimates for breast cancer mortality according to age at RRSO (50 years of age or less versus more than 50 years) was not protective and did not differ for BRCA1 (HR 0.85, 95% CI 0.64 to 1.11; I² = 16%; P = 0.23; very low-certainty evidence) and BRCA2 carriers (HR 0.88, 95% CI 0.42 to 1.87; I² = 63%; P = 0.75; very low-certainty evidence).

AUTHORS' CONCLUSIONS

There is very low-certainty evidence that RRSO may increase overall survival and lower HGSC and breast cancer mortality for BRCA1 and BRCA2 carriers. Very low-certainty evidence suggests that RRSO reduces the risk of death from HGSC and breast cancer in women with BRCA1 mutations. Evidence for the effect of RRSO on HGSC and breast cancer in BRCA2 carriers was very uncertain due to low numbers. These results should be interpreted with caution due to questionable study designs, risk of bias profiles, and very low-certainty evidence. We cannot draw any conclusions regarding bone fracture incidence, quality of life, or severe adverse events for RRSO, or for effects of RRSO based on type and age at risk-reducing surgery. Further research on these outcomes is warranted to explore differential effects for BRCA1 or BRCA2 mutations.

Pathogenesis and heterogeneity of ovarian cancer

PURPOSE OF REVIEW

The most common type of ovarian cancer, high-grade serous ovarian carcinoma (HGSOC), was originally thought to develop from the ovarian surface epithelium. However, recent data suggest that the cells that undergo neoplastic transformation and give rise to the majority of HGSOC are from the fallopian tube. This development has impacted both translational research and clinical practice, revealing new opportunities for early detection, prevention, and treatment of ovarian cancer.

RECENT FINDINGS

Genomic studies indicate that approximately 50% of HGSOC are characterized by mutations in genes involved in the homologous recombination pathway of DNA repair, especially BRCA1 and BRCA2. Clinical trials have demonstrated successful treatment of homologous recombination-defective cancers with poly-ribose polymerase inhibitors through synthetic lethality. Recently, amplification of CCNE1 was found to be another major factor in HGSOC tumorigenesis, accounting for approximately 20% of all cases. Interestingly, amplification of CCNE1 and mutation of homologous recombination repair genes are mutually exclusive in HGSOC.

SUMMARY

The fallopian tube secretory cell is the cell of origin for the majority of ovarian cancers. Although it remains unclear what triggers neoplastic transformation of these cells, certain tumors exhibit loss of BRCA function or amplification of CCNE1. These alterations represent unique therapeutic opportunities in ovarian cancer.

Persistence of fimbrial tissue on the ovarian surface after salpingectomy

BACKGROUND

Salpingectomy is recommended as a risk-reducing strategy for epithelial tubo-ovarian cancer. The gold standard procedure is complete tubal excision.

OBJECTIVE

The purpose of this study was to assess the presence of residual fimbrial/tubal tissue on ovarian surfaces after salpingectomy.

STUDY DESIGN

Prospective analysis of patients who underwent salpingo-oophorectomy with or without hysterectomy for benign indications, early cervical cancer, or low-risk endometrial cancer at a UK National Health Service Trust. Salpingectomy with or without hysterectomy was performed initially, followed by oophorectomy within the same operation. Separately retrieved tubes and ovaries were sectioned serially and examined completely histologically. The main outcome measure was histologically identified fimbrial/ tubal tissue on ovarian surface. Chi-square/Fisher's exact tests were used to evaluate categoric variables.

RESULTS

Twenty-five consecutive cases (mean age, 54.8 ± 5.0 years) that comprised 41 adnexae (unilateral, 9; bilateral, 16) were analyzed. Seventeen (68.0%), 5 (20.0%), and 3 (12.0%) procedures were performed by consultant gynecologists, subspecialty/specialist trainees, and consultant gynecologic oncologists, respectively. Twelve of 25 procedures (48.0%) were laparoscopic, and 13 of 25 procedures (52.0%) involved laparotomy. Four of 25 patients (16.0%; 95% confidence interval, 4.5-36.1%) or 4 of 41 adnexae (9.8%; 95% confidence interval, 2.7-23.1%) showed residual microscopic fimbrial tissue on the ovarian surface. Tubes/ovaries were free of adhesions in 23 cases. Two cases had dense adnexal adhesions, but neither had residual fimbrial tissue on the ovary. Residual fimbrial tissue was not associated significantly with surgical route or experience (consultant, 3/20 [15%]; trainee, 1/5 [20%]; P=1.0).

CONCLUSION

Residual fimbrial tissue remains on the ovary after salpingectomy in a significant proportion of cases and could impact the level of risk-reduction that is obtained.

Directed Differentiation of Human Induced Pluripotent Stem Cells into Fallopian Tube Epithelium

The fallopian tube epithelium (FTE) has been recognized as a site of origin of high-grade serous ovarian cancer (HGSC). However, the absence of relevant in vitro human models that can recapitulate tissue-specific architecture has hindered our understanding of FTE transformation and initiation of HGSC. Here, induced pluripotent stem cells (iPSCs) were used to establish a novel 3-dimensional (3D) human FTE organoid in vitro model containing the relevant cell types of the human fallopian tube as well as a luminal architecture that closely reflects the organization of fallopian tissues in vivo. Modulation of Wnt and BMP signaling directed iPSC differentiation into Müllerian cells and subsequent use of pro-Müllerian growth factors promoted FTE precursors. The expression and localization of Müllerian markers verified correct cellular differentiation. An innovative 3D growth platform, which enabled the FTE organoid to self-organize into a convoluted luminal structure, permitted matured differentiation to a FTE lineage. This powerful human-derived FTE organoid model can be used to study the earliest stages of HGSC development and to identify novel and specific biomarkers of early fallopian tube epithelial cell transformation.

The Putative Role of TP53 Alterations and p53 Expression in Borderline Ovarian Tumors - Correlation with Clinicopathological Features and Prognosis: A Mini-Review

Borderline ovarian tumors (BOTs) represent an independent group among ovarian malignancies, being diagnosed at clinical stage earlier than invasive ovarian carcinomas (OCs) and characterized by a rather favorable outcome after careful surgical management. Data published worldwide showed a substantial discordance of p53 expression in BOTs. The purpose of this work was to present the current status of knowledge on the significance of TP53 gene and p53 protein product alterations in BOTs. In general, higher p53 expression patterns were reported for ovarian malignancies compared to BOTs. Serous, mucinous, and endometrioid BOTs differ substantially in relation to p53 immunostaining, but data concerning the relationship between the protein's immunoreactivity and other clinico-pathological variables are scarce. Finally, reports published to date support the view that TP53 alterations may not be commonly associated with the borderline phenotype of ovarian tumors but they probably occur during the development of invasive OCs. In light of these uncertainties, the impact of TP53 alterations and p53 expression on overall survival in women affected by BOTs requires further multi-institutional studies in large cohorts of patients.

Serous Tubal Carcinogenesis: The Recent Concept of Origin of Ovarian, Primary Peritoneal and Fallopian Tube High-Grade Serous Carcinoma

Background

Pelvic (non-uterine) high-grade serous carcinomas (PHGSC) including ovarian, tubal and primary peritoneal serous carcinomas have increased death: incidence ratio due to presentation at advanced stage, rapid progression, poor prognosis and high morbidity. Ambiguity regarding their pathogenesis and lack of a proper screening method is the cause of their late detection and high fatality rate. This study was undertaken to assess the fallopian tube for the presence of precursor lesions in pelvic serous carcinoma.

Methods

This was a prospective case-control study carried out in a tertiary care center. Consecutive specimens of 55 cases of pelvic high-grade serous carcinoma and 41 controls inclusive of 21 low-grade serous carcinoma, 10 benign adnexal masses and 10 normal adnexa were included in the study. Both side fallopian tubes in each case were subjected to histopathological examination and p53, Ki67 immunohistochemistry.

Results

There were 55 cases of PHGSC comprising of 50 cases of ovarian HGSC, two cases of primary peritoneal carcinoma (PPC) and three cases of tubal carcinoma. Serous tubal intraepithelial carcinoma (STIC) was detected in 14 cases (28%), p53 signature in 13 cases (26%) and tubal intraepithelial lesion in transition in 10 cases (20%) of ovarian HGSC. One case (50%) of PPC and one (33%) case of tubal carcinoma revealed the presence of STIC. None of the controls exhibited any precursor lesion except ovarian low-grade serous carcinoma where p53 was detected in 20% of cases.

Conclusion

This revelation concludes that fallopian tubes are the sites of precursors of PHGSC to a large extent. In the absence of a proper screening method of HGSC, prophylactic bilateral salpingectomy at hysterectomy for benign diseases can achieve ultimate goal of reduction in incidence of PHGSC.

The disparate origins of ovarian cancers: pathogenesis and prevention strategies

Ovarian cancer is the fifth cause of cancer-related death in women and comprises a histologically and genetically broad range of tumours, including those of epithelial, sex cord-stromal and germ cell origin. Recent evidence indicates that high-grade serous ovarian carcinoma, clear cell carcinoma and endometrioid carcinoma primarily arise from tissues that are not normally present in the ovary. These histogenetic pathways are informing risk-reduction strategies for the prevention of ovarian and ovary-associated cancers and have highlighted the importance of the seemingly unique ovarian microenvironment.

[The morphological and immunohistochemical characteristics of changes in the fallopian tube mucosa in ovarian epithelial tumors]

AIM

to study the incidence of fallopian tube lesions (secretory cell proliferations (SCP), p53 signature, serous tubal intraepithelial lesions (STIL), and serous tubal intraepithelial carcinomas (STIC) in ovarian epithelial tumors and to propose their pathogenetic association with a certain histotype of the ovarian tumor.

MATERIAL AND METHODS

The investigation enrolled 136 patients with ovarian epithelial tumors, whose fallopian tubes were morphologically and immunohistochemically (IHC) examined using p53, Ki-67, and PAX2. Statistical analysis was carried out applying the Mann-Whitney test and χ(2) test.

RESULTS

Lesions meeting the STIC criteria were found in 14.7% of cases (only in ovarian serous carcinoma (OSC)), those suspecting STICs were in 25.7%, and those without signs of STICs were in 59.6%. IFC examination diagnosed STIC in 10% of cases (only in OSC), STIL in 13.3%, p53 signature in 11.7% (only in serous tumors), and the normal/reactively changed tubal epithelium in 65%. The incidence of STILs correlated with the malignant potential of serous tumors significantly (p<0.05). There were significant differences in the incidence of STILs in patients with different histotypes of ovarian carcinomas (p<0.05). PAX2-negative SCP was detected in 75% of OSC, 60% of serous borderline tumors, and 40% of serous cystadenomas. The differences in the incidence of SCP between serous tumors of varying grade, between serous tumors and non-serous carcinomas, between OSC and non-serous carcinomas were significant (p<0.05).

CONCLUSION

The investigation has shown that IHC examination should be used for the accurate diagnosis of STILs. It has also provided evidence for the pathogenetic association between STIC and high-grade OSC and revealed significant differences in the incidence of other fallopian tubal intraepithelial lesions in serous cystadenomas, borderline tumors, and OSC, in different ovarian carcinomas. The findings may suggest that the earliest stage in the pathogenesis of OSC is the development of SCP, followed by the formation of p53 signatures that may further give rise to STIL, and finally STC (due to the acquisition of additional mutations).

Characterization of precursor lesions in the endometrium and fallopian tube epithelium of early-stage uterine serous carcinoma

To determine if selected cases of uterine serous carcinoma (USC) arise from tubal rather than endometrial epithelium. Bilateral fallopian tubes from 38 women with pure USC were entirely submitted for histopathologic examination using the protocol Sectioning and Extensively Examining the FIMbria (SEE-FIM). Non-neoplastic endometrium was extensively sampled. Immunohistochemistry for p53 was performed on all paraffin blocks of fallopian tube and non-neoplastic endometrium. Endometrial intraepithelial carcinoma (EIC) was present in 22 cases (58%). Endometrial p53 foci were identified in 3 patients. There were 11 cases (29%) with fallopian tube involvement; 9 of 11 had tubal wall invasion or lymphatic involvement without serous tubal intraepithelial carcinoma (STIC) and were, therefore, classified as metastatic from the endometrium. STIC was identified in 3 patients (8%). There were 3 cases with tubal p53 foci in non-neoplastic epithelium. EIC was present in 58% of patients, further supporting EIC as a precursor lesion to USC. STIC was present in 8%, suggesting that the fallopian tube may in fact represent the primary lesion in a minority of patients with USC. This finding may account for the early multifocal disease distribution observed in these patients.

Early salpingectomy (TUbectomy) with delayed oophorectomy to improve quality of life as alternative for risk-reducing salpingo-oophorectomy in BRCA1/2 mutation carriers (TUBA study): a prospective non-randomised multicentre study

Background

Risk-reducing salpingo-oophorectomy (RRSO) around the age of 40 is currently recommended to BRCA1/2 mutation carriers. This procedure decreases the elevated ovarian cancer risk by 80–96 % but it initiates premature menopause as well. The latter is associated with short-term and long-term morbidity, potentially affecting quality of life (QoL). Based on recent insights into the Fallopian tube as possible site of origin of serous ovarian carcinomas, an alternative preventive strategy has been put forward: early risk-reducing salpingectomy (RRS) and delayed oophorectomy (RRO). However, efficacy and safety of this alternative strategy have to be investigated.

Methods

A multicentre non-randomised trial in 11 Dutch centres for hereditary cancer will be conducted. Eligible patients are premenopausal BRCA1/2 mutation carriers after completing childbearing without (a history of) ovarian carcinoma. Participants choose between standard RRSO at age 35–40 (BRCA1) or 40–45 (BRCA2) and the alternative strategy (RRS upon completion of childbearing and RRO at age 40–45 (BRCA1) or 45–50 (BRCA2)). Women who opt for RRS but do not want to postpone RRO beyond the currently recommended age are included as well. Primary outcome measure is menopause-related QoL. Secondary outcome measures are ovarian/breast cancer incidence, surgery-related morbidity, histopathology, cardiovascular risk factors and diseases, and cost-effectiveness. Mixed model data analysis will be performed.

Discussion

The exact role of the Fallopian tube in ovarian carcinogenesis is still unclear. It is not expected that further fundamental research will elucidate this role in the near future. Therefore, this clinical trial is essential to investigate RRS with delayed RRO as alternative risk-reducing strategy in order to improve QoL.

Trial registration

ClinicalTrials.gov (NCT02321228)

[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.

Ovulation and extra-ovarian origin of ovarian cancer

The mortality rate of ovarian cancer remains high due to late diagnosis and recurrence. A fundamental step toward improving detection and treatment of this lethal disease is to understand its origin. A growing number of studies have revealed that ovarian cancer can develop from multiple extra-ovarian origins, including fallopian tube, gastrointestinal tract, cervix and endometriosis. However, the mechanism leading to their ovarian localization is not understood. We utilized in vitro, ex vivo, and in vivo models to recapitulate the process of extra-ovarian malignant cells migrating to the ovaries and forming tumors. We provided experimental evidence to support that ovulation, by disrupting the ovarian surface epithelium and releasing chemokines/cytokines, promotes the migration and adhesion of malignant cells to the ovary. We identified the granulosa cell-secreted SDF-1 as a main chemoattractant that recruits malignant cells towards the ovary. Our findings revealed a potential molecular mechanism of how the extra-ovarian cells can be attracted by the ovary, migrate to and form tumors in the ovary. Our data also supports the association between increased ovulation and the risk of ovarian cancer. Understanding this association will lead us to the development of more specific markers for early detection and better prevention strategies.

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.

Refractory fallopian tube carcinoma - current perspectives in pathogenesis and management

Fallopian tube carcinoma (FTC) is considered a rare malignancy, but recent evidence shows that its incidence may have been underestimated. Risk-reducing salpingo-oophorectomy (RRSO) in breast cancer susceptibility gene (BRCA)-positive women has provided a unique opportunity to study the pathogenesis of FTC and ovarian carcinomas. Newer data now suggest that most high-grade serous cancers of the ovary originate in the fimbrial end of the fallopian tube. Due to the presumed rarity of FTC, most current and more recent ovarian cancer clinical trials have now included patients with FTC. The treatment guidelines recommend similar overall management and that the same chemotherapy regimens be used for epithelial ovarian cancers and FTC.

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.

Clinicopathologic study of serous tubal intraepithelial carcinoma with invasive carcinoma: is serous tubal intraepithelial carcinoma a reliable feature for determining the organ of origin?

In the past several decades, the concept of serous ovarian carcinoma has been revised repeatedly. However, the exact pathogenesis remains controversial. The most popular current concept is origin from the epithelium of the fimbriated ends of the fallopian tubes. The objective of our study was to evaluate the characteristic clinical and morphologic features of serous tubal intraepithelial carcinoma (STIC) and associated invasive carcinomas. One hundred sixteen consecutive cases of STIC seen from 2007 to 2011 were included in this study. High-grade serous carcinoma (HGSC) with or without a mixed component was identified in 107 cases (92.2%), non-HGSC in 5 cases, and STICs without invasive carcinoma in 4 cases. Using conventional criteria, HGSCs were classified as fallopian tube in origin in 65 cases (60.7%), as ovarian in 30 (28.0%), as peritoneal in 9 (8.4%), and as endometrial in 3 (2.8%). Among the 107 cases with HGSCs, most STICs (86; 80%) were present unilaterally, whereas invasive tumors more commonly involved the ovaries bilaterally (79%; 84 cases). These findings support the hypothesis that STIC acts as a precursor lesion for most fallopian tube, ovarian, and peritoneal HGSCs, but not for endometrial HGSC.

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.

Expression of human telomerase reverse transcriptase in vulvar intraepithelial neoplasia and squamous cell carcinoma: an immunohistochemical study with survivin and p53

CONTEXT

Human telomerase reverse transcriptase (hTERT), an enzyme that enables cells to overcome replicative senescence and to divide indefinitely, is overexpressed in many cancers and their precursor lesions.

OBJECTIVE

To test whether hTERT expression is related to neoplastic progression and resistance to apoptosis in vulvar epithelia.

DESIGN

Immunoexpression of hTERT was evaluated in 101 formalin-fixed, paraffin-embedded archival vulvar epithelia consisting of normal squamous vulvar epithelia (n  =  25), lichen sclerosus (n  =  10), high-grade classic vulvar intraepithelial neoplasia (n  =  16), differentiated vulvar intraepithelial neoplasia (n  =  18), and vulvar invasive keratinizing squamous cell carcinoma (n  =  32) and related to survivin and p53 expression. Immunostaining for all factors was scored for moderate and strong intensities with regard to quantity to determine upregulation and overexpression (score 0, 0% immunoreactive cells; score 1+, <5% immunoreactive cells; score 2+, 5% to 50% immunoreactive cells; score 3+, >50% immunoreactive cells). Score 3+ was considered as overexpression.

RESULTS

Nuclear hTERT immunoexpression was closely related to survivin reactivity, increased from normal vulvar squamous epithelia to lichen sclerosus and to high-grade classic vulvar intraepithelial neoplasia, differentiated vulvar intraepithelial neoplasia, and invasive keratinizing squamous cell carcinoma (P < .001), and followed the morphologic distribution of atypical squamous epithelial cells. Overexpression of hTERT was comparable to that seen for p53 in invasive keratinizing squamous cell carcinoma (P  =  .62); significant differences were calculated for differentiated vulvar intraepithelial neoplasia (P  =  .003) and high-grade classic vulvar intraepithelial neoplasia (P  =  .001).

CONCLUSION

Human telomerase reverse transcriptase is upregulated in vulvar intraepithelial neoplasia and invasive keratinizing squamous cell carcinoma compared with nonneoplastic squamous epithelia of the vulva as an apparently early and preinvasive event in the neoplastic transformation, with development of cellular longevity and resistance to apoptosis by survivin activation as associated features, independent of the etiology of vulvar intraepithelial neoplasia.

E2F3b over-expression in ovarian carcinomas and in BRCA1 haploinsufficient fallopian tube epithelium

We have previously shown that the E2F3 oncogene is up-regulated as part of a "preneoplastic expression profile" in fallopian tube epithelium (FTE) of women with BRCA1 mutations. We studied E2F3 expression in FTE and carcinomas of women with BRCA1 or BRCA2 mutations or wildtype for both genes. Significantly more foci of TP53 positive cells in histologically normal FTE from women with BRCA1 mutations but not in wildtype or BRCA2 mutated individuals had E2F3 protein overexpression relative to adjacent normal FTE, which occurred in the context of focally increased proliferation, potentially explaining the increased neoplastic potential of tubal TP53 foci in women with BRCA1 mutations. To assess mechanisms of E2F3 deregulation in ovarian or tubal carcinogenesis, we studied E2F3 and its two isoforms E2F3a and E2F3b in wild-type ovarian carcinomas and ovarian carcinomas associated with germline BRCA1 and BRCA2 mutations. The expression of E2F3b, but not E2F3a, was correlated with the expression of BRCA1 in all three genetic groups. In primary cultures of FTE from women with BRCA1 mutation or wildtype for BRCA1 and BRCA2, siRNA-induced BRCA1 deficiency led to increased E2F3b but not E2F3a expression. Our results suggest that E2F3b and BRCA1 are functionally connected, and BRCA1 haploinsufficiency in normal FTE may lead to up-regulation of E2F3b and increased proliferation before the development of intraepithelial neoplasia. These data support that E2F3b up-regulation is an important preneoplastic event in FTE from BRCA1 mutation carriers.

The oviduct and ovarian cancer: causality, clinical implications, and "targeted prevention"

A novel origin for pelvic serous cancer (ovarian cancer) has been proposed in the distal oviduct. This has important implications, including both early detection in high-risk women and wisdom of relying on serological tests to detect a disease that begins so close to the peritoneal surfaces. With the recent discovery of premalignant disturbances in gene function in the tubal mucosa, the concept of targeted prevention is emerging whereby the interruption of a portion of the carcinogenic pathway will prevent cancer. This alternative to detect early malignancy is a new paradigm in the quest to prevent this deadly disease.

BRCA, the oviduct, and the space and time continuum of pelvic serous carcinogenesis

In recent years, the distal oviduct has emerged as a critical organ in the pathogenesis of pelvic ("ovarian") serous cancer. Studies have uncovered early serous tubal intraepithelial carcinomas in approximately 8% of asymptomatic women with germline BRCA1 or BRCA2 mutations, linked serous tubal intraepithelial carcinomas to one half of serous cancers irrespective of genetic risk, and described a precursor lesion in the distal tube with early alterations in p53 function (the p53 signature). This work has established a linear serous carcinogenic sequence in a single focus within the fimbria. In addition, a more broadly distributed array of gene alterations has been discovered in the oviduct, manifested as secretory (or stem) cell outgrowths that are increased in frequency as a function of older age and serous cancer status. These "surrogate precursors" expand the existing model beyond the fimbria, implying that the molecular events leading to serous cancer are distributed over space and time. The potential promise of these discoveries is "targeted prevention" by discovering of multiple pathways integral to carcinogenesis and successfully preventing malignancy by interrupting one or a few of these pathways.