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

Genetic alterations and their therapeutic implications in epithelial ovarian cancer

BACKGROUND

Genetic alterations for epithelial ovarian cancer are insufficiently characterized. Previous studies are limited regarding included histologies, gene numbers, copy number variant (CNV) detection, and interpretation of pathway alteration patterns of individual patients.

METHODS

We sequenced 410 genes to analyze mutations and CNV of 82 ovarian carcinomas, including high-grade serous (n = 37), endometrioid (n = 22) and clear cell (n = 23) histologies. Eligibility for targeted therapy was determined for each patient by a pathway-based approach. The analysis covered DNA repair, receptor tyrosine kinase, PI3K/AKT/MTOR, RAS/MAPK, cell cycle, and hedgehog pathways, and included 14 drug targets.

RESULTS

Postulated PARP, MTOR, and CDK4/6 inhibition sensitivity were most common. BRCA1/2 alterations, PTEN loss, and gain of PIK3CA and CCND1 were characteristic for high-grade serous carcinomas. Mutations of ARID1A, PIK3CA, and KRAS, and ERBB2 gain were enriched in the other histologies. PTEN mutations and high tumor mutational burden were characteristic for endometrioid carcinomas. Drug target downstream alterations impaired actionability in all histologies, and many alterations would not have been discovered by key gene mutational analysis. Individual patients often had more than one actionable drug target.

CONCLUSIONS

Genetic alterations in ovarian carcinomas are complex and differ among histologies. Our results aid the personalization of therapy and biomarker analysis for clinical studies, and indicate a high potential for combinations of targeted therapies.

Molecular Signatures of Gynecological Cancers: Clinicians Perspective

Large-scale molecular profiling and DNA sequencing has revolutionized cancer research. Precision medicine is a rapidly developing area in cancer care but it is not uniformly applied across different tumor types. Biomarker-based therapy is associated with improved outcomes, both in terms of progression-free survival and overall survival. Comprehensive genomic profiling (CGP) uses next-generation sequencing to analyze the complete coding sequence of hundreds of genes from a small amount of tissue. Genes included in these assays are those associated with cancer development or have diagnostic, prognostic, familial, or therapeutic implications Genomic profiling is emerging as a clinically viable tool to personalize patient's treatment. This article discusses how the insights gained through CGP can impact treatment plan in common gynecological cancers.

Mutations of Intrinsically Disordered Protein Regions Can Drive Cancer but Lack Therapeutic Strategies

Many proteins contain intrinsically disordered regions (IDRs) which carry out important functions without relying on a single well-defined conformation. IDRs are increasingly recognized as critical elements of regulatory networks and have been also associated with cancer. However, it is unknown whether mutations targeting IDRs represent a distinct class of driver events associated with specific molecular and system-level properties, cancer types and treatment options. Here, we used an integrative computational approach to explore the direct role of intrinsically disordered protein regions driving cancer. We showed that around 20% of cancer drivers are primarily targeted through a disordered region. These IDRs can function in multiple ways which are distinct from the functional mechanisms of ordered drivers. Disordered drivers play a central role in context-dependent interaction networks and are enriched in specific biological processes such as transcription, gene expression regulation and protein degradation. Furthermore, their modulation represents an alternative mechanism for the emergence of all known cancer hallmarks. Importantly, in certain cancer patients, mutations of disordered drivers represent key driving events. However, treatment options for such patients are currently severely limited. The presented study highlights a largely overlooked class of cancer drivers associated with specific cancer types that need novel therapeutic options.

Re-assigning the histologic identities of COV434 and TOV-112D ovarian cancer cell lines

OBJECTIVE

The development of effective cancer treatments depends on the availability of cell lines that faithfully recapitulate the cancer in question. This study definitively re-assigns the histologic identities of two ovarian cancer cell lines, COV434 (originally described as a granulosa cell tumour) and TOV-112D (originally described as grade 3 endometrioid carcinoma), both of which were recently suggested to represent small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), based on their shared gene expression profiles and sensitivity to EZH2 inhibitors.

METHODS

For COV434 and TOV-112D, we re-reviewed the original pathology slides and obtained clinical follow-up on the patients, when available, and performed immunohistochemistry for SMARCA4, SMARCA2 and additional diagnostic markers on the original formalin-fixed, paraffin-embedded (FFPE) clinical material, when available. For COV434, we further performed whole exome sequencing and validated SMARCA4 mutations by Sanger sequencing. We studied the growth of the cell lines at baseline and upon re-expression of SMARCA4 in vitro for both cell lines and evaluated the serum calcium levels in vivo upon injection into immunodeficient mice for COV434 cells.

RESULTS

The available morphological, immunohistochemical, genetic, and clinical features indicate COV434 is derived from SCCOHT, and TOV-112D is a dedifferentiated carcinoma. Transplantation of COV434 into mice leads to increased serum calcium level. Re-expression of SMARCA4 in either COV434 and TOV-112D cells suppressed their growth dramatically.

CONCLUSIONS

COV434 represents a bona fide SCCOHT cell line. TOV-112D is a dedifferentiated ovarian carcinoma cell line.

CTNNB1 Mutations and Aberrant β-Catenin Expression in Ovarian Endometrioid Carcinoma: Correlation With Patient Outcome

CTNNB1 mutations and aberrant β-catenin expression have adverse prognosis in endometrial endometrioid carcinoma, and recent evidence suggests a prognostic role of β-catenin in ovarian endometrioid carcinoma. Thus, we aimed to determine the prognostic value of the CTNNB1 mutational status, and its correlation with β-catenin expression, in a well-annotated cohort of 51 ovarian endometrioid carcinomas. We performed immunohistochemistry for β-catenin and developed an 11-gene next-generation sequencing panel that included whole exome sequencing of CTNNB1 and TP53. Results were correlated with clinicopathologic variables including disease-free and disease-specific survival. Tumor recurrence was documented in 14 patients (27%), and cancer-related death in 8 patients (16%). CTNNB1 mutations were found in 22 cases (43%), and nuclear β-catenin in 26 cases (51%). CTNNB1 mutation highly correlated with nuclear β-catenin (P<0.05). Mutated CTNNB1 status was statistically associated with better disease-free survival (P=0.04, log-rank test) and approached significance for better disease-specific survival (P=0.07). It also correlated with earlier International Federation of Gynecology and Obstetrics stage (P<0.05). Nuclear β-catenin, TP53 mutations, age, ProMisE group, surface involvement, tumor grade and stage also correlated with disease-free survival. There was no association between membranous β-catenin expression and disease-free or disease-specific survival. CTNNB1 mutations and nuclear β-catenin expression are associated with better progression-free survival in patients with OEC. This relationship may be in part due to a trend of CTNNB1-mutated tumors to present at early stage. β-catenin immunohistochemistry may serve as a prognostic biomarker and a surrogate for CTNN1B mutations in the evaluation of patients with ovarian endometrioid neoplasia, particularly those in reproductive-age or found incidentally without upfront staging surgery.

Cross-Cancer Genome-Wide Association Study of Endometrial Cancer and Epithelial Ovarian Cancer Identifies Genetic Risk Regions Associated with Risk of Both Cancers

BACKGROUND

Accumulating evidence suggests a relationship between endometrial cancer and ovarian cancer. Independent genome-wide association studies (GWAS) for endometrial cancer and ovarian cancer have identified 16 and 27 risk regions, respectively, four of which overlap between the two cancers. We aimed to identify joint endometrial and ovarian cancer risk loci by performing a meta-analysis of GWAS summary statistics from these two cancers.

METHODS

Using LDScore regression, we explored the genetic correlation between endometrial cancer and ovarian cancer. To identify loci associated with the risk of both cancers, we implemented a pipeline of statistical genetic analyses (i.e., inverse-variance meta-analysis, colocalization, and M-values) and performed analyses stratified by subtype. Candidate target genes were then prioritized using functional genomic data.

RESULTS

Genetic correlation analysis revealed significant genetic correlation between the two cancers (rG = 0.43, P = 2.66 × 10-5). We found seven loci associated with risk for both cancers (P Bonferroni < 2.4 × 10-9). In addition, four novel subgenome-wide regions at 7p22.2, 7q22.1, 9p12, and 11q13.3 were identified (P < 5 × 10-7). Promoter-associated HiChIP chromatin loops from immortalized endometrium and ovarian cell lines and expression quantitative trait loci data highlighted candidate target genes for further investigation.

CONCLUSIONS

Using cross-cancer GWAS meta-analysis, we have identified several joint endometrial and ovarian cancer risk loci and candidate target genes for future functional analysis.

IMPACT

Our research highlights the shared genetic relationship between endometrial cancer and ovarian cancer. Further studies in larger sample sets are required to confirm our findings.

Primary endometrioid carcinoma of the uterosacral ligament arising from deep infiltrating endometriosis 6 years after bilateral salpingo-oophorectomy due to atypical proliferative endometrioid tumor of the ovary: a rare case report

BACKGROUND

Endometriosis can potentially lead to the development of a malignant tumor. Most malignant tumors arising from the endometriosis originate from the ovarian endometrioma, whereas those arising from extragonadal lesions are rare. We report a rare case of endometrioid carcinoma that developed from deep infiltrating endometriosis in the uterosacral ligament 6 years after treatment for atypical proliferative endometrioid tumor of the ovary in a 48-year-old woman.

CASE PRESENTATION

Six years ago, the patient underwent laparoscopic bilateral salpingo-oophorectomy for her right ovarian tumor with atypical proliferative (borderline) endometrioid tumor accompanied by ovarian endometrioma. The solid tumor in the cul-de-sac was detected during follow-up using magnetic resonance imaging. Positron emission tomography/computed tomography revealed an abnormal accumulation of ¹⁸F-fluorodeoxyglucose at the tumor site. Thus, tumor recurrence with borderline malignancy was suspected. The patient underwent diagnostic laparoscopy followed by hysterectomy and partial omentectomy. Retroperitoneal pelvic lymphadenectomy and para-aortic lymphadenectomy were also performed. The cul-de-sac tumor at the left uterosacral ligament was microscopically diagnosed as invasive endometrioid carcinoma arising from deep infiltrating endometriosis. The final diagnosis was primary stage IIB peritoneal carcinoma. The patient received six courses of monthly paclitaxel and carboplatin as adjuvant chemotherapy. The patient showed no evidence of recurrence for 2 years after the treatments.

CONCLUSION

This study reports a rare case of metachronous endometriosis-related malignancy that developed 6 years after treatment for borderline ovarian tumor. If endometriosis lesions remain after bilateral salpingo-oophorectomy, the physician should keep the malignant nature of endometriosis in mind.

Comprehensive genomic profiling reveals ubiquitous KRAS mutations and frequent PIK3CA mutations in ovarian seromucinous borderline tumor

The molecular underpinnings of seromucinous borderline tumor (SMBT) - an uncommon ovarian epithelial neoplasm characterized by association with endometriosis, frequent bilateral ovarian involvement, and occasional progression to invasive carcinoma - remain poorly understood. Here, we sought to comprehensively characterize the mutational landscape of SMBT and elucidate the clonal relationship between bilateral ovarian SMBTs. We also compared the mutational profiles between SMBTs and concurrent invasive carcinomas. Formalin-fixed, paraffin-embedded tissue specimens were retrieved from 28 patients diagnosed with SMBT. Massively parallel sequencing of 409 cancer-related genes was conducted to identify somatic mutations in 33 SMBT samples and four concurrent invasive carcinoma specimens. TERT promoter mutations were assessed by Sanger sequencing, whereas immunohistochemistry was used as a surrogate tool for detecting deletions or epigenetic silencing of relevant tumor suppressor genes. Twenty-six (92.9%) of the 28 patients were diagnosed with stage I SMBTs. Seven (25%) cases showed bilateral ovarian involvement and 13 (46%) had concomitant endometriosis. Concurrent ovarian carcinomas were identified in three patients, whereas one case had a synchronous endometrial carcinoma. Somatic mutations in the KRAS, PIK3CA, and ARID1A genes were identified in 100, 60.7, and 14.3% of SMBT samples, respectively. In contrast, TERT promoter mutations and DNA mismatch repair deficiencies were absent. Sequencing of paired specimens from patients with bilateral SMBT revealed the presence of at least two shared somatic mutations, suggestive of a clonal relationship. Similarly, we identified shared somatic mutations between SMBT samples and concurrent ovarian carcinoma specimens. Taken together, these findings demonstrated a distinct mutational landscape of SMBT in which (1) KRAS is invariably mutated, (2) PIK3CA is frequently mutated, and (3) TERT promoter mutations and DNA mismatch repair deficiencies are absent. Our findings represent the first extensive characterization of this rare ovarian neoplasm, with potential implications for disease classification and molecular diagnostics.

Uterine carcinosarcoma: Contemporary clinical summary, molecular updates, and future research opportunity

Uterine carcinosarcoma (UCS) is a biphasic aggressive high-grade endometrial cancer in which the sarcoma element has de-differentiated from the carcinoma element. UCS is considered a rare tumor, but its incidence has gradually increased in recent years (annual percent change from 2000 to 2016 1.7%, 95% confidence interval 1.2-2.2) as has the proportion of UCS among endometrial cancer, exceeding 5% in recent years. UCS typically affects the elderly, but in recent decades patients became younger. Notably, a stage-shift has occurred in recent years with increasing nodal metastasis and decreasing distant metastasis. The concept of sarcoma dominance may be new in UCS, and a sarcomatous element >50% of the uterine tumor is associated with decreased survival. Multimodal treatment is the mainstay of UCS. Lymphadenectomy, chemotherapy, and brachytherapy have increased in the past few decades, but survival outcomes remain dismal: the median survival is less than two years, and the 5-year overall survival rate has not changed in decades (31.9% in 1975 to 33.8% in 2012). Carboplatin/paclitaxel adjuvant chemotherapy improves progression-free survival compared with ifosfamide/paclitaxel, particularly in stages III-IV disease (GOG-261 trial). Twenty-six clinical trials previously examined therapeutic effectiveness in recurrent/metastatic UCS. The median response rate and progression-free survival were 37.5% and 5.9 months, respectively, after first-line therapy, but after later therapies, the outcomes were far worse (5.5% and 1.8 months, respectively). One significant discovery was that epithelial-mesenchymal transition (EMT) plays a pivotal role in the pathogenesis of sarcomatous dedifferentiation in UCS and that heterologous sarcoma is associated with a higher EMT signature compared with homologous sarcoma. Furthermore, next-generation sequencing has revealed that UCS tumors are serous-like and that common somatic mutations include those in TP53, PIK3CA, FBXW7, PTEN, and ARID1A. This contemporary review highlights recent clinical and molecular updates in UCS. A possible therapeutic target of EMT in UCS is also discussed.

Transcription factors in epithelial ovarian cancer: histotype-specific drivers and novel therapeutic targets

Transcription factors (TFs) are major contributors to cancer risk and somatic development. In preclinical and clinical studies, direct or indirect inhibition of TF-mediated oncogenic gene expression profiles have proven to be effective in many tumor types, highlighting this group of proteins as valuable therapeutic targets. In spite of this, our understanding of TFs in epithelial ovarian cancer (EOC) is relatively limited. EOC is a heterogeneous disease composed of five major histologic subtypes; high-grade serous, low-grade serous, endometrioid, clear cell and mucinous. Each histology is associated with unique clinical etiologies, sensitivity to therapies, and molecular signatures - including diverse transcriptional regulatory programs. While some TFs are shared across EOC subtypes, a set of TFs are expressed in a histotype-specific manner and likely explain part of the histologic diversity of EOC subtypes. Targeting TFs present with unique opportunities for development of novel precision medicine strategies for ovarian cancer. This article reviews the critical TFs in EOC subtypes and highlights the potential of exploiting TFs as biomarkers and therapeutic targets.

Molecular Heterogeneity of Endometrioid Ovarian Carcinoma: An Analysis of 166 Cases Using the Endometrial Cancer Subrogate Molecular Classification

Endometrioid ovarian carcinoma (EOC) has clinical and biological differences compared with other histologic types of ovarian carcinomas, but it shares morphologic and molecular features with endometrioid endometrial carcinoma. To analyze the molecular heterogeneity of EOC according to the new molecular classification of endometrial cancer and to evaluate the prognostic significance of this molecular classification, we have analyzed 166 early-stage EOC by immunohistochemistry for mismatch repair proteins and p53 expression, and by Sanger sequencing for the exonuclease domain of polymerase epsilon (POLE EDM). In addition, we have carried out next-generation sequencing analysis of tumors with POLE EDM mutations to confirm the ultramutated profile. Eight tumors carried POLE EDM mutations and were classified as ultramutated (5%), 29 showed mismatch repair deficiency and were classified as hypermutated (18%), 16 tumors had a mutated pattern of p53 expression and were classified as p53 abnormal (11%), and 114 tumors did not have any of the previous alterations and were classified as no specific type (66%). Five tumors showed >1 classification criteria. The frequencies of ultramutated and hypermutated tumors were lower in EOC compared with the frequency reported in endometrial cancer. Subrogate molecular groups differed in both morphologic features (histologic grade, squamous and morular metaplasia, and necrosis) and immunohistochemical expression of several biomarkers (ARID1A, nuclear β-catenin, estrogen receptors, Napsin A, and HINF1B). In addition, the number of CD8 tumor-infiltrating lymphocytes was higher in ultramutated and hypermutated tumors. The most commonly mutated genes in the ultramutated group were ARID1A (100%), PIK3R1, PTEN, BCOR, and TP53 (67% each), whereas no mutations were detected in KRAS. Although the prognosis did not differ among subgroups in the multivariate analysis, a trend toward a better prognosis in POLE-mutated and a worse prognosis in p53 abnormal tumors was observed. In addition, this classification could have important therapeutic implications for the use of immunotherapy in tumors classified as ultramutated and hypermutated.

CTNNB1 p.L31P mutation in an ovarian endometrioid carcinoma with synchronous uterine endometrioid carcinoma

We performed next generation sequencing of DNA extracted from the neoplastic tissues obtained from a patient who underwent surgery for a large right ovarian carcinoma (OC) of endometrioid type associated with endometrial cancer (EC). This was done in order to ascertain whether the tumors were synchronous endometrial/ovarian cancers or an advanced metastatic stage from either the ovary or the uterus. Pathologic criteria favoured synchronous EC/OC. We identified a PTEN c.959 T > G (p.L320X) truncating mutation occurring with similar allele frequency in both neoplastic tissues (ovary: 88 %, endometrium 89 %) and a CTNNB1 c.100C > G (p.S37C) activating mutation, with a comparable allelic frequency in both tumor tissues (ovary 51 %, endometrium 52 %). The shared genetic mutations, and the presence of PTEN c.959 T > G (p.L320X) truncating mutation, albeit at low allelic frequency (6 %), in the healthy peritumoral endometrial tissue, appear to confirm the recent literature on a primary endometrial origin for synchronous EC/OC. A third mutation was CTNNB1 c.92 T > C (p.L31 P), a missense mutation occurring with a low allele frequency (3.7 %) only in the ovarian cancer tissue. This mutation is only occasionally described in hepatocellular carcinomas.

Clinicopathological and molecular analyses of linearly expanded epithelial cells with β-catenin alterations, "β-catenin signature", in the normal fallopian tube

AIMS

Recent advances in next-generation sequencing have made it clear that clonal expansion of cells harbouring driver gene mutations occurs in physiologically normal epithelium. Molecular analysis of tubal epithelium has been almost exclusively confined to the TP53 pathway, which is involved in serous carcinogenesis. Other oncogenic events have not been explored in detail. Here, we report the linear expansion of fallopian tubal epithelial cells exhibiting an altered β-catenin profile (β-catenin signature). Through molecular analyses, we determined the incidence and clinicopathological significance of β-catenin signatures.

METHODS AND RESULTS

We evaluated 64 specimens of surgically removed bilateral fallopian tubes. Thirty-three β-catenin signatures were identified in 13 cases (20.3%); these patients were significantly younger than those without β-catenin signatures (median ages of 44 and 57 years, respectively, P = 0.0317). No correlation between β-catenin signature and any clinical factor was observed. CTNNB1 mutations were detected in three of eight β-catenin signatures when tissues were microdissected and subjected to Sanger sequencing in two representative cases.

CONCLUSIONS

This is the first report of the CTNNB1 mutation in clusters of morphologically bland tubal epithelial cells. The results of this study indicate that β-catenin signatures are common, and they may be a part of diverse molecular alterations occurring in normal tubal epithelium.

Molecular stratification of endometrioid ovarian carcinoma predicts clinical outcome

Endometrioid ovarian carcinoma (EnOC) demonstrates substantial clinical and molecular heterogeneity. Here, we report whole exome sequencing of 112 EnOC cases following rigorous pathological assessment. We detect a high frequency of mutation in CTNNB1 (43%), PIK3CA (43%), ARID1A (36%), PTEN (29%), KRAS (26%), TP53 (26%) and SOX8 (19%), a recurrently-mutated gene previously unreported in EnOC. POLE and mismatch repair protein-encoding genes were mutated at lower frequency (6%, 18%) with significant co-occurrence. A molecular taxonomy is constructed, identifying clinically distinct EnOC subtypes: cases with TP53 mutation demonstrate greater genomic complexity, are commonly FIGO stage III/IV at diagnosis (48%), are frequently incompletely debulked (44%) and demonstrate inferior survival; conversely, cases with CTNNB1 mutation, which is mutually exclusive with TP53 mutation, demonstrate low genomic complexity and excellent clinical outcome, and are predominantly stage I/II at diagnosis (89%) and completely resected (87%). Moreover, we identify the WNT, MAPK/RAS and PI3K pathways as good candidate targets for molecular therapeutics in EnOC.

Atypical endometriosis is related to a higher recurrence rate

OBJECTIVES

The aims of this study were to evaluate the clinical characteristics and recurrence rate of atypical endometriosis (AE)¹ compared to typical endometriosis (TE) in addition to the malignant transformation rate among a large cohort.

STUDY DESIGN

The medical records of 2681 patients who had undergone surgical treatment of ovarian endometrioma between January 2008 and September 2019 were retrospectively reviewed. The patients were divided into AE (n = 86) and TE (n = 2595) groups. Patients' characteristics and recurrence rates were evaluated and compared between the two groups.

RESULTS

The mean size of ovarian cysts was significantly larger in the AE group (7.6 ± 3.5 cm vs 6.7 ± 3.3 cm, p = 0.01) and the proportion of nulliparous women was significantly lower in AE group (65.1 % vs 77.8 %, p = 0.008). Otherwise, there were no statistically significant differences in patient characteristics between the two groups. After Cox regression analyses with IPTW was adjusted, the risk factors for recurrent endometrioma were higher preoperative CA125 level >48 U/mL (hazard ratio [HR] = 2.741; 95 % confidence interval [CI] = 1.517-4.952; p < 0.001), multilocular cyst (HR = 1.909; 95 % CI = 1.128-3.230; p = 0.016), and atypical endometriosis (HR = 2.666; 95 % CI = 1.659-4.284; p < 0.001). The AE group displayed a significantly higher cumulative recurrence rate than the TE group (p = 0.0057, log-rank test). No patients were diagnosed with atypical endometriosis to malignant transformation during the follow-up periods. However, two typical endometriosis patients experienced borderline malignancy and serous carcinoma, respectively.

CONCLUSION

Recurrence rates for AE were higher than for TE. Although the AE group included no patient with malignant transformation in this study, considering the higher recurrence as well as the possibility of malignant transformation, long-term close surveillance is warranted.

Clinical and pathological associations of PTEN expression in ovarian cancer: a multicentre study from the Ovarian Tumour Tissue Analysis Consortium

BACKGROUND

PTEN loss is a putative driver in histotypes of ovarian cancer (high-grade serous (HGSOC), endometrioid (ENOC), clear cell (CCOC), mucinous (MOC), low-grade serous (LGSOC)). We aimed to characterise PTEN expression as a biomarker in epithelial ovarian cancer in a large population-based study.

METHODS

Tumours from 5400 patients from a multicentre observational, prospective cohort study of the Ovarian Tumour Tissue Analysis Consortium were used to evaluate associations between immunohistochemical PTEN patterns and overall survival time, age, stage, grade, residual tumour, CD8+ tumour-infiltrating lymphocytes (TIL) counts, expression of oestrogen receptor (ER), progesterone receptor (PR) and androgen receptor (AR) by means of Cox proportional hazard models and generalised Cochran-Mantel-Haenszel tests.

RESULTS

Downregulation of cytoplasmic PTEN expression was most frequent in ENOC (most frequently in younger patients; p value = 0.0001) and CCOC and was associated with longer overall survival in HGSOC (hazard ratio: 0.78, 95% CI: 0.65-0.94, p value = 0.022). PTEN expression was associated with ER, PR and AR expression (p values: 0.0008, 0.062 and 0.0002, respectively) in HGSOC and with lower CD8 counts in CCOC (p value < 0.0001). Heterogeneous expression of PTEN was more prevalent in advanced HGSOC (p value = 0.019) and associated with higher CD8 counts (p value = 0.0016).

CONCLUSIONS

PTEN loss is a frequent driver in ovarian carcinoma associating distinctly with expression of hormonal receptors and CD8+ TIL counts in HGSOC and CCOC histotypes.

Morphological and molecular heterogeneity of epithelial ovarian cancer: Therapeutic implications

Ovarian epithelial cancer (OEC) is the most lethal gynecologic malignancy. Despite current chemotherapeutic and surgical options, this high lethality can be attributed to multiple factors, including late-stage presentation. In order to optimize OEC treatment, it is important to highlight that it is composed of five main subtypes: high-grade serous ovarian carcinoma (HGSOC), low-grade serous ovarian carcinoma (LGSOC), endometrioid ovarian carcinoma (EOC), ovarian clear cell carcinoma (CCOC), and mucinous ovarian carcinoma (MOC). These subtypes differ in their precursor lesions, as well as in epidemiological, morphological, molecular and clinical features. OEC is one of the tumours in which most pathogenic germline mutations have been identified. Accordingly, up to 20% OC show alterations in BRCA1/2 genes, and also, although with a lower frequency, in other low penetrance genes associated with homologous recombination deficiency (HRD), mismatch repair genes (Lynch syndrome) and TP53. The most important prognostic factor is the 2014 FIGO staging, while older age is also associated with worse survival. HGSOC in all stages and CCC and MOC in advanced stages have the worse prognosis among histological types. Molecular markers have emerged as prognostic factors, particularly mutations in BRCA1/2, which are associated with a better outcome. Regarding treatment, whereas a proportion of HGSOC is sensible to platinum-based treatment and PARP inhibitors due to HRD, the rest of the histological types are relatively chemoresistant. New treatments based in specific molecular alterations are being tested in different histological types. In addition, immunotherapy could be an option, especially for EOC carrying mismatch repair deficiency or POLE mutations.

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The five different histological types have different precursor lesions and epidemiological, morphological, genetic, epigenetic and clinical features.

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Histological type is an important prognostic factor.

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Drugs targeting homologous recombination deficiency have been approved for treatment.

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The use of immunotherapy is limited due to lack of predictive biomarkers

Endometrial Cancer Molecular Risk Stratification is Equally Prognostic for Endometrioid Ovarian Carcinoma

PURPOSE

Endometrioid ovarian carcinoma (ENOC) is generally associated with a more favorable prognosis compared with other ovarian carcinomas. Nonetheless, current patient treatment continues to follow a "one-size-fits-all" approach. Even though tumor staging offers stratification, personalized treatments remain elusive. As ENOC shares many clinical and molecular features with its endometrial counterpart, we sought to investigate The Cancer Genome Atlas-inspired endometrial carcinoma (EC) molecular subtyping in a cohort of ENOC.

EXPERIMENTAL DESIGN

IHC and mutation biomarkers were used to segregate 511 ENOC tumors into four EC-inspired molecular subtypes: low-risk POLE mutant (POLEmut), moderate-risk mismatch repair deficient (MMRd), high-risk p53 abnormal (p53abn), and moderate-risk with no specific molecular profile (NSMP). Survival analysis with established clinicopathologic and subtype-specific features was performed.

RESULTS

A total of 3.5% of cases were POLEmut, 13.7% MMRd, 9.6% p53abn, and 73.2% NSMP, each showing distinct outcomes (P < 0.001) and survival similar to observations in EC. Median OS was 18.1 years in NSMP, 12.3 years in MMRd, 4.7 years in p53abn, and not reached for POLEmut cases. Subtypes were independent of stage, grade, and residual disease in multivariate analysis.

CONCLUSIONS

EC-inspired molecular classification provides independent prognostic information in ENOC. Our findings support investigating molecular subtype-specific management recommendations for patients with ENOC; for example, subtypes may provide guidance when fertility-sparing treatment is desired. Similarities between ENOC and EC suggest that patients with ENOC may benefit from management strategies applied to EC and the opportunity to study those in umbrella trials.

Signaling Modulations of miR-206-3p in Tooth Morphogenesis

MicroRNAs (miRNAs) are a class of naturally occurring small non-coding RNAs that post-transcriptionally regulate gene expression in organisms. Most mammalian miRNAs influence biological processes, including developmental changes, tissue morphogenesis and the maintenance of tissue identity, cell growth, differentiation, apoptosis, and metabolism. The miR-206-3p has been correlated with cancer; however, developmental roles of this miRNA are unclear. In this study, we examined the expression pattern and evaluated the developmental regulation of miR-206-3p during tooth morphogenesis using ex-vivo culture method. The expression pattern of miR-206-3p was examined in the epithelium and mesenchyme of developing tooth germ with stage-specific manners. Perturbation of the expression of miR-206-3p clearly altered expression patterns of dental-development-related signaling molecules, including Axin2, Bmp2, Fgf4, Lef1 and Shh. The gene expression complemented with change in cellular events including, apoptosis and proliferation which caused altered crown and pulp morphogenesis in renal-capsule-calcified teeth. Especially, mislocalization of β-Catenin and SMAD1/5/8 were observed alongside dramatic alterations in the expression patterns of Fgf4 and Shh. Overall, our data suggest that the miR-206-3p regulate the cellular physiology during tooth morphogenesis through modulation of the Wnt, Bmp, Fgf, and Shh signaling pathways to form proper tooth pulp and crown.

The Landscape and Therapeutic Implications of Molecular Profiles in Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) affects 43,000 women worldwide every year and has a five-year survival rate of 30%. Mainstay treatment is extensive surgery and chemotherapy. Outcomes could be improved by molecular profiling. We conducted a review of the literature to identify relevant publications on molecular and genetic alterations in EOC. Approximately 15% of all EOCs are due to BRCA1 or BRCA2 mutations. Four histologic subtypes characterized by different mutations have been described: serous, endometrioid, mucinous, and clear-cell. Between 20–30% of high-grade serous EOCs have a BRCA mutation. Tumors with BRCA mutations are unable to repair double-strand DNA breaks, making them more sensitive to platinum-based chemotherapy and to PolyAdenosine Diphosphate-Ribose Polymerase (PARP) inhibitors. Olaparib is a PARP inhibitor with proven efficacy in BRCA-mutated ovarian cancer, but its effectiveness remains to be demonstrated in tumors with a BRCAness (breast cancer) profile (i.e., also including sporadic tumors in patients with deficient DNA repair genes). A universally accepted molecular definition of BRCAness is required to identify optimal theranostic strategies involving PARP inhibitors. Gene expression analyses have led to the identification of four subgroups of high-grade serous EOC: mesenchymal, proliferative, differentiated, and immunoreactive. These subtypes are not mutually exclusive but are correlated with prognosis. They are not yet used in routine clinical practice. A greater understanding of EOC subtypes could improve patient management.

Inactivation of Arid1a in the endometrium is associated with endometrioid tumorigenesis through transcriptional reprogramming

Somatic inactivating mutations of ARID1A, a SWI/SNF chromatin remodeling gene, are prevalent in human endometrium-related malignancies. To elucidate the mechanisms underlying how ARID1A deleterious mutation contributes to tumorigenesis, we establish genetically engineered murine models with Arid1a and/or Pten conditional deletion in the endometrium. Transcriptomic analyses on endometrial cancers and precursors derived from these mouse models show a close resemblance to human uterine endometrioid carcinomas. We identify transcriptional networks that are controlled by Arid1a and have an impact on endometrial tumor development. To verify findings from the murine models, we analyze ARID1A^WT and ARID1A^KO human endometrial epithelial cells. Using a system biology approach and functional studies, we demonstrate that ARID1A-deficiency lead to loss of TGF-β tumor suppressive function and that inactivation of ARID1A/TGF-β axis promotes migration and invasion of PTEN-deleted endometrial tumor cells. These findings provide molecular insights into how ARID1A inactivation accelerates endometrial tumor progression and dissemination, the major causes of cancer mortality.

ARID1A, which is often mutated in human endometrial cancer, is a component of the SWI/SNF chromatin remodelling complex. Here, the authors show that Arid1a mutations in the mouse endometrium and primary human endometrial epithelial cells cause widespread reprogramming of gene transcription and result in a loss of response to TGFβ.

TOOme: A Novel Computational Framework to Infer Cancer Tissue-of-Origin by Integrating Both Gene Mutation and Expression

Metastatic cancers require further diagnosis to determine their primary tumor sites. However, the tissue-of-origin for around 5% tumors could not be identified by routine medical diagnosis according to a statistics in the United States. With the development of machine learning techniques and the accumulation of big cancer data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), it is now feasible to predict cancer tissue-of-origin by computational tools. Metastatic tumor inherits characteristics from its tissue-of-origin, and both gene expression profile and somatic mutation have tissue specificity. Thus, we developed a computational framework to infer tumor tissue-of-origin by integrating both gene mutation and expression (TOOme). Specifically, we first perform feature selection on both gene expressions and mutations by a random forest method. The selected features are then used to build up a multi-label classification model to infer cancer tissue-of-origin. We adopt a few popular multiple-label classification methods, which are compared by the 10-fold cross validation process. We applied TOOme to the TCGA data containing 7,008 non-metastatic samples across 20 solid tumors. Seventy four genes by gene expression profile and six genes by gene mutation are selected by the random forest process, which can be divided into two categories: (1) cancer type specific genes and (2) those expressed or mutated in several cancers with different levels of expression or mutation rates. Function analysis indicates that the selected genes are significantly enriched in gland development, urogenital system development, hormone metabolic process, thyroid hormone generation prostate hormone generation and so on. According to the multiple-label classification method, random forest performs the best with a 10-fold cross-validation prediction accuracy of 96%. We also use the 19 metastatic samples from TCGA and 256 cancer samples downloaded from GEO as independent testing data, for which TOOme achieves a prediction accuracy of 89%. The cross-validation validation accuracy is better than those using gene expression (i.e., 95%) and gene mutation (53%) alone. In conclusion, TOOme provides a quick yet accurate alternative to traditional medical methods in inferring cancer tissue-of-origin. In addition, the methods combining somatic mutation and gene expressions outperform those using gene expression or mutation alone.

ASPM is a predictor of overall survival and has therapeutic potential in endometrial cancer

BACKGROUND

Endometrial carcinoma (EC) is one of the most common cancers in women, and its pathogenesis is complex. Abnormal spindle microtubule assembly (ASPM) is highly expressed in a variety of cancers and is related to poor clinical prognosis and recurrence. However, the role of ASPM in EC is still unclear. Our study was conducted to investigate the association of ASPM with tumour progression and prognosis in EC.

METHODS

The expression level of ASPM in EC patients was analysed by using the TCGA database and by using immunohistochemistry (IHC) to analyse EC patient samples. The relationship between ASPM expression and clinicopathological variables was analysed by the chi-square test. Survival curves were analysed by Kaplan-Meier survival analysis and log-rank test. Univariate and multivariate Cox regression analyses were performed to measure the prognosis of EC. The effects of ASPM on the proliferation, invasion and metastasis of EC cells (HEC-1A and Ishikawa) were analysed by MTT and Transwell assays. The effect of ASPM on the Wnt/β-catenin signalling pathway was detected by Western blotting.

RESULTS

ASPM was highly overexpressed in EC. Overexpression of ASPM was related to significantly worse overall survival (P<0.05) in EC patients. Univariate and multivariate Cox regression analyses suggested that upregulation of ASPM was related to poor prognosis in EC. Knockdown of ASPM inhibited the proliferation, migration and invasion of EC cells. ASPM knockdown suppressed the Wnt/β-catenin signalling pathway, while β-catenin overexpression reversed the effect of shASPM on cell activity.

CONCLUSIONS

ASPM acts as an independent predictor of clinical prognosis and serves as a potential target gene for EC therapy.

Arginine Depletion Therapy with ADI-PEG20 Limits Tumor Growth in Argininosuccinate Synthase-Deficient Ovarian Cancer, Including Small-Cell Carcinoma of the Ovary, Hypercalcemic Type

PURPOSE

Many rare ovarian cancer subtypes, such as small-cell carcinoma of the ovary, hypercalcemic type (SCCOHT), have poor prognosis due to their aggressive nature and resistance to standard platinum- and taxane-based chemotherapy. The development of effective therapeutics has been hindered by the rarity of such tumors. We sought to identify targetable vulnerabilities in rare ovarian cancer subtypes.

EXPERIMENTAL DESIGN

We compared the global proteomic landscape of six cases each of endometrioid ovarian cancer (ENOC), clear cell ovarian cancer (CCOC), and SCCOHT to the most common subtype, high-grade serous ovarian cancer (HGSC), to identify potential therapeutic targets. IHC of tissue microarrays was used as validation of arginosuccinate synthase (ASS1) deficiency. The efficacy of arginine-depriving therapeutic ADI-PEG20 was assessed in vitro using cell lines and patient-derived xenograft mouse models representing SCCOHT.

RESULTS

Global proteomic analysis identified low ASS1 expression in ENOC, CCOC, and SCCOHT compared with HGSC. Low ASS1 levels were validated through IHC in large patient cohorts. The lowest levels of ASS1 were observed in SCCOHT, where ASS1 was absent in 12 of 31 cases, and expressed in less than 5% of the tumor cells in 9 of 31 cases. ASS1-deficient ovarian cancer cells were sensitive to ADI-PEG20 treatment regardless of subtype in vitro. Furthermore, in two cell line mouse xenograft models and one patient-derived mouse xenograft model of SCCOHT, once-a-week treatment with ADI-PEG20 (30 mg/kg and 15 mg/kg) inhibited tumor growth in vivo.

CONCLUSIONS

Preclinical in vitro and in vivo studies identified ADI-PEG20 as a potential therapy for patients with rare ovarian cancers, including SCCOHT.

Female adnexal tumors of probable Wolffian origin: morphological, immunohistochemical, and molecular analysis of 15 cases

Female adnexal tumors of probable Wolffian origin are rare and present a diagnostic challenge due to their morphological and immunohistochemical overlap with more common ovarian and broad ligament entities. We evaluated the morphological, immunohistochemical, and molecular features of 15 tumors of probable Wolffian origin. Patients ranged from 32 to 69 (mean 47) years and tumors from 1.8 to 30 (mean 10) cm. All except one arose in para-adnexal soft tissues. Follow-up was available for six patients, five of whom were alive and well, while the sixth, who had extra-adnexal disease at diagnosis, died from unrelated causes. The following patterns were noted: tubular (all tumors), solid 11/15 (73%), sieve-like 7/15 (47%), and reticular 1/15 (7%). A myxoid background was present in 3/15 (20%) of tumors and eosinophilic luminal secretions in 11/15 (73%). Most tumors (12/15, 80%) had low-grade nuclear atypia, while three showed foci with scattered high-grade atypia. Mitotic index ranged from 0 to 17 (mean 4) per ten high-power fields. Tumors were positive for pankeratin and negative for TTF-1. EMA, GATA3, and PAX8 were positive in 2/10 (20%; focal), 3/15 (20%; focal), and 1/15 (7%; focal) of tumors, respectively. CD10, SF-1, calretinin, inhibin, ER, PR, cytokeratin 7, and WT1 were variably expressed. Pathogenic mutations were rare and included STK11 (n = 3), APC (n = 1), and MBD4 (n = 1). Copy number variations were detected in the three tumors with STK11 mutations and a myxoid background. These data demonstrate that female adnexal tumors of probable Wolffian origin are morphologically and immunohistochemically diverse, but infrequently harbor pathogenic mutations. However, their lack of mutations in contrast to their mimickers may be a valuable tool in diagnostically difficult cases.

Ovarian Endometrioid Carcinoma Misdiagnosed as Mucinous Carcinoma: An Underrecognized Problem

Primary mucinous carcinoma of the ovary is uncommon, and while numerous studies have focused on improving our ability to distinguish these tumors from gastrointestinal metastases, recent data suggest that up to one fifth are still misdiagnosed with a previously underrecognized culprit: endometrioid carcinoma. Using an index case of an ovarian endometrioid carcinoma with mucinous differentiation masquerading as a mucinous carcinoma, we sought to identify the most efficient biomarker combination that could distinguish these 2 histotypes. Eight immunohistochemical markers were assessed on tissue microarrays from 183 endometrioid carcinomas, 77 mucinous carcinomas, and 72 mucinous borderline tumors. Recursive partitioning revealed a simple 2-marker panel consisting of PR and vimentin. The combination of PR absence and vimentin absence could predict mucinous tumors with a sensitivity of 95.1%, a specificity of 96.7%, and an overall accuracy of 96.0%. Additional marker combinations did not improve accuracy. The 5-yr ovarian cancer-specific survival for mucinous carcinoma was significantly worse than endometrioid carcinoma (70% vs. 86%, respectively, P=0.02). Our proposed 2-marker algorithm allows diagnostic distinction between mucinous and endometrioid ovarian carcinomas when morphology is not straightforward. Given key differences in the underlying biology and clinical behavior of these 2 histotypes, improved diagnostic precision is essential for guiding appropriate management and treatment.

An integrated molecular profile of endometrioid ovarian cancer

OBJECTIVE

Endometrioid ovarian carcinoma (EOVC) is an uncommon subtype of epithelial ovarian carcinoma and its molecular characteristics have been incompletely described. Prior sequencing investigations have been limited to targeted gene panels. We performed whole-exome sequencing to build an unbiased genetic profile of molecular alterations in endometrioid ovarian tumors with a goal to better understand this disease in the context of epithelial ovarian cancer and endometrioid uterine cancers.

METHODS

Whole-exome sequencing was performed on EOVC samples (n = 26) and matched normals (n = 15). Gene mutations, mutational signatures and copy number variations (CNVs) informed a multi-dimensional regression classifier allowing for comparison to endometrial carcinoma (UCEC) and high grade serous ovarian carcinoma (HGSC).

RESULTS

EOVC has a distinct and heterogeneous genomic profile. Identified significantly mutated genes in EOVC (PTEN, CTNNB1, PIK3CA, KMT2D, KMT2B, PIK3R1, ARID1A and TP53) occurred at similar frequencies in UCEC. Hypermutation, resulting from both mismatch repair deficiency (MMRd) and POLE mutation, was observed in EOVC at a frequency similar to UCEC. Like UCEC, a subset of EOVC cases closely resembled HGSC, harboring TP53 mutations, homologous recombination deficiency (HRd) mutation signatures and widespread CNVs. A machine-learning classifier confirmed the heterogeneous composition of EOVC. Potential therapeutic targets were identified in 62% of EOVC cases. We validated our findings in an orthogonal clinical sequencing registry of EOVC cases.

CONCLUSIONS

We identified that EOVC are a molecularly heterogeneous group of epithelial ovarian cancers with distinct mutational signatures. In an age of precision oncology, there is a pressing need to understand the unique molecular drivers in uncommon histologic subtypes to facilitate genomically driven oncologic treatments.

Cyclooxygenase-2 and β-Catenin as Potential Diagnostic and Prognostic Markers in Endometrial Cancer

Objectives: Explore the diagnostic and prognostic value of cyclooxygenase-2 and wnt3a/β-catenin pathway in endometrial cancer.

Methods: A prospective cohort study of 93 women underwent hysterectomy at the China-Japan Friendship Hospital (61 patients with primary endometrial carcinoma, and 32 control patients with uterine prolapse or leiomyoma of uterus). Cox2 and β-catenin expression were determined by immunohistochemistry. The serum levels of cox2 and wnt3a were detected via ELISA assays.

Results: Patients with endometrial cancer showed overexpression of cox2 and β-catenin, as well as significantly higher serum levels of cox2 and wnt3a. The serum cox2 level, which is highly significant in predicting the risk of disease progression (RR, 9.617, 95% confidence interval, 1.162–79.622, P = 0.036), showed good diagnostic and prognostic potential, with cut-off of 55 U/L, but alongside β-catenin expression in tissues, were related to poor prognosis (RR, 12.426; 95% confidence interval, 1.618–95.450; P = 0.015).

Conclusion: Serum levels of cox2 and wnt3a exhibited diagnostic value for endometrial cancer. Cox2 serum levels and β-catenin expression also showed potential value of prognostic prediction. Cox2 serum levels might be a potential marker for early diagnosis and prognosis prediction in endometrial cancer.

Molecular profiling identifies synchronous endometrial and ovarian cancers as metastatic endometrial cancer with favorable clinical outcome

Synchronous primary endometrial and ovarian cancers (SEOs) represent 10% of all endometrial and ovarian cancers and are assumed to develop as independent entities. We investigated the clonal relationship between endometrial and ovarian carcinomas in a large cohort classified as SEOs or metastatic disease (MD). The molecular profiles were compared to The Cancer Genome Atlas (TCGA) data to explore primary origin. Subsequently, the molecular profiles were correlated with clinical outcome. To this extent, a retrospective multicenter study was performed comparing patients with SEOs (n = 50), endometrial cancer with synchronous ovarian metastasis (n = 19) and ovarian cancer with synchronous endometrial metastasis (n = 20). Targeted next‐generation sequencing was used, and a clonality index was calculated. Subsequently, cases were classified as POLE mutated, mismatch repair deficient (MMR‐D), TP53‐wild‐type or TP53‐mutated. In 92% of SEOs (46/50), the endometrial and concurrent ovarian carcinoma shared at least one somatic mutation, with a clonality index above 0.95, supporting a clonal origin. The SEO molecular profiles showed striking similarities with the TCGA endometrial carcinoma set. SEOs behaved distinctly different from metastatic disease, with a superior outcome compared to endometrial MD cases (p < 0.001) and ovarian MD cases (p < 0.001). Classification according to the TCGA identified four groups with different clinical outcomes. TP53 mutations and extra‐utero‐ovarian disease were independent predictors for poor clinical outcome. Concluding, SEOs were clonally related in an overwhelming majority of cases and showed a favorable prognosis. Their molecular profile implied a primary endometrial origin. TP53 mutation and extra‐utero‐ovarian disease were independent predictors for outcome, and may impact adjuvant systemic treatment planning.

What's new?

When primary endometrial and ovarian tumors are found simultaneously in the same patient, it has been assumed that they are separate cancers that developed independently. However, in this study, the authors found that these tumors share a clonal origin 92% of the time. They also found that these “synchronous” cancers tend to have a favorable prognosis, with far better outcomes than metastatic disease. Some subgroups, including TP53 mutations and extra‐utero‐ovarian disease, were independent predictors for poor clinical outcome, which may impact adjuvant treatment planning.

Ovarian Cancer Dissemination-A Cell Biologist's Perspective

Epithelial ovarian cancer (EOC) comprises multiple disease states representing a variety of distinct tumors that, irrespective of tissue of origin, genetic aberrations and pathological features, share common patterns of dissemination to the peritoneal cavity. EOC peritoneal dissemination is a stepwise process that includes the formation of malignant outgrowths that detach and establish widespread peritoneal metastases through adhesion to serosal membranes. The cell biology associated with outgrowth formation, detachment, and de novo adhesion is at the nexus of diverse genetic backgrounds that characterize the disease. Development of treatment for metastatic disease will require detailed characterization of cellular processes involved in each step of EOC peritoneal dissemination. This article offers a review of the literature that relates to the current stage of knowledge about distinct steps of EOC peritoneal dissemination, with emphasis on the cell biology aspects of the process.

Pathology of Endometrioid and Clear Cell Carcinoma of the Ovary

This review is an appraisal of the current state of knowledge of 2 enigmatic histotypes of ovarian carcinoma: endometrioid and clear cell carcinoma. Both show an association endometriosis and the hereditary nonpolyposis colorectal cancer (Lynch) syndrome, and both typically present at an early stage. Pathologic and immunohistochemical features that distinguish these tumors from high-grade serous carcinomas, each other, and other potential mimics are discussed, as are staging, grading, and molecular pathogenesis.

Endometriosis-associated ovarian cancer is not a distinct clinical entity among young patients: A 12-year cohort study

OBJECTIVES

To investigate the clinicopathological features and prognostic value of endometriosis in young patients with ovarian endometrioid carcinoma (OEC) and ovarian clear cell carcinoma (OCCC).

METHODS

The medical files and clinical follow-up data of patients aged 40 years or younger with OEC or OCCC between January 2006 and December 2017 who had undergone complete surgical staging followed by systemic chemotherapy were retrospectively reviewed.

RESULTS

A total of 94 women were included in this study. Univariate analysis revealed that the progression-free survival (PFS) and overall survival (OS) rates of patients with endometriosis-associated ovarian carcinoma (EAOC) did not improve compared with those of patients without EAOC (5-year PFS: 80.0% vs. 75.9% and 5-year OS: 85.0% vs. 86.0%, respectively). Multivariate analyses confirmed that FIGO stage (II-IV), cytology-positive ascites or peritoneal washes and residual disease > 1 cm were independent predictors of PFS and that residual disease > 1 cm was the only predictor of OS.

CONCLUSIONS

Endometriosis is not independently associated with the prognosis of OEC and OCCC among young patients. The intrinsic relationship between endometriosis and ovarian cancer warrants further investigation.

Clonal Expansion and Diversification of Cancer-Associated Mutations in Endometriosis and Normal Endometrium

Endometriosis is characterized by ectopic endometrial-like epithelium and stroma, of which molecular characteristics remain to be fully elucidated. We sequenced 107 ovarian endometriotic and 82 normal uterine endometrial epithelium samples isolated by laser microdissection. In both endometriotic and normal epithelium samples, numerous somatic mutations were identified within genes frequently mutated in endometriosis-associated ovarian cancers. KRAS is frequently mutated in endometriotic epithelium, with a higher mutant allele frequency (MAF) accompanied by arm-level allelic imbalances. Analyses of MAF, combined with multiregional sequencing, illuminated spatiotemporal evolution of the endometriosis and uterine endometrium genomes. We sequenced 109 single endometrial glands and found that each gland carried distinct cancer-associated mutations, demonstrating the heterogeneity of the genomic architecture of endometrial epithelium. Remarkable increases in MAF of mutations in cancer-associated genes in endometriotic epithelium suggest retrograde flow of endometrial cells already harboring cancer-associated mutations, with selective advantages at ectopic sites, leading to the development of endometriosis.

Protein tyrosine phosphatase receptor type R (PTPRR) antagonizes the Wnt signaling pathway in ovarian cancer by dephosphorylating and inactivating β-catenin

Despite a lack of mutations, accumulating evidence supports an important role for the Wnt/β-catenin pathway in ovarian tumorigenesis. However, the molecular mechanism that contributes to the aberrant activation of the Wnt signaling cascade in ovarian cancer has not been fully elucidated. Here, we found that protein tyrosine phosphatase receptor type R (PTPRR) suppressed the activation of the Wnt/β-catenin pathway in ovarian cancer. We performed an shRNA-based biochemical screen, which identified PTPRR as being responsible for tyrosine dephosphorylation of β-catenin on Tyr-142, a key site controlling the transcriptional activity of β-catenin. Of note, PTPRR was down-regulated in ovarian cancers, and ectopic PTPRR re-expression delayed ovarian cancer cell growth both in vitro and in vivo Using a proximity-based tagging system and RNA-Seq analysis, we identified a signaling nexus that includes PTPRR, α-catenin, β-catenin, E-cadherin, and AT-rich interaction domain 3C (ARID3C) in ovarian cancer. Immunohistochemistry staining of human samples further suggested that PTPRR expression is inversely correlated with disease prognosis. Collectively, our findings indicate that PTPRR functions as a tumor suppressor in ovarian cancer by dephosphorylating and inactivating β-catenin. These results suggest that PTPRR expression might have utility as a prognostic marker for predicting overall survival.

Clinical actionability of molecular targets in endometrial cancer

Endometrial cancer accounts for ~76,000 deaths among women each year worldwide. Disease mortality and the increasing number of new diagnoses make endometrial cancer an important consideration in women's health, particularly in industrialized countries, where the incidence of this tumour type is highest. Most endometrial cancers are carcinomas, with the remainder being sarcomas. Endometrial carcinomas can be classified into several histological subtypes, including endometrioid, serous and clear cell carcinomas. Histological subtyping is currently used routinely to guide prognosis and treatment decisions for endometrial cancer patients, while ongoing studies are evaluating the potential clinical utility of molecular subtyping. In this Review, we summarize the overarching molecular features of endometrial cancers and highlight recent studies assessing the potential clinical utility of specific molecular features for early detection, disease risk stratification and directing targeted therapies.

Molecular profiling and molecular classification of endometrioid ovarian carcinomas

OBJECTIVE

Endometrioid ovarian carcinomas (EOCs) comprise 5-10% of all ovarian cancers and commonly co-occur with synchronous endometrioid endometrial cancer (EEC). We sought to examine the molecular characteristics of pure EOCs in patients without concomitant EEC.

METHODS

EOCs and matched normal samples were subjected to massively parallel sequencing targeting 341-468 cancer-related genes (n = 8) or whole-genome sequencing (n = 28). Mutational frequencies of EOCs were compared to those of high-grade serous ovarian cancers (HGSOCs; n = 224) and EECs (n = 186) from The Cancer Genome Atlas, and synchronous EOCs (n = 23).

RESULTS

EOCs were heterogeneous, frequently harboring KRAS, PIK3CA, PTEN, CTNNB1, ARID1A and TP53 mutations. EOCs were distinct from HGSOCs at the mutational level, less frequently harboring TP53 but more frequently displaying KRAS, PIK3CA, PIK3R1, PTEN and CTNNB1 mutations. Compared to synchronous EOCs and pure EECs, pure EOCs less frequently harbored PTEN, PIK3R1 and ARID1A mutations. Akin to EECs, EOCs could be stratified into the four molecular subtypes: 3% POLE (ultramutated), 19% MSI (hypermutated), 17% copy-number high (serous-like) and 61% copy-number low (endometrioid). In addition to microsatellite instability, a subset of EOCs harbored potentially targetable mutations, including AKT1 and ERBB2 hotspot mutations. EOCs of MSI (hypermutated) subtype uniformly displayed a good outcome.

CONCLUSIONS

EOCs are heterogeneous at the genomic level and harbor targetable genetic alterations. Despite the similarities in the repertoire of somatic mutations between pure EOCs, synchronous EOCs and EECs, the frequencies of mutations affecting known driver genes differ. Further studies are required to define the impact of the molecular subtypes on the outcome and treatment of EOC patients.

Epithelial ovarian cancer: Evolution of management in the era of precision medicine

Ovarian cancer is the second most common cause of gynecologic cancer death in women around the world. The outcomes are complicated, because the disease is often diagnosed late and composed of several subtypes with distinct biological and molecular properties (even within the same histological subtype), and there is inconsistency in availability of and access to treatment. Upfront treatment largely relies on debulking surgery to no residual disease and platinum-based chemotherapy, with the addition of antiangiogenic agents in patients who have suboptimally debulked and stage IV disease. Major improvement in maintenance therapy has been seen by incorporating inhibitors against poly (ADP-ribose) polymerase (PARP) molecules involved in the DNA damage-repair process, which have been approved in a recurrent setting and recently in a first-line setting among women with BRCA1/BRCA2 mutations. In recognizing the challenges facing the treatment of ovarian cancer, current investigations are enlaced with deep molecular and cellular profiling. To improve survival in this aggressive disease, access to appropriate evidence-based care is requisite. In concert, realizing individualized precision medicine will require prioritizing clinical trials of innovative treatments and refining predictive biomarkers that will enable selection of patients who would benefit from chemotherapy, targeted agents, or immunotherapy. Together, a coordinated and structured approach will accelerate significant clinical and academic advancements in ovarian cancer and meaningfully change the paradigm of care.

Dickkopf1: An immunomodulatory ligand and Wnt antagonist in pathological inflammation

The Wnt signaling pathway plays essential roles in tissue or organ homeostasis by regulating cell proliferation and differentiation. Upon tissue or organ injury, inflammation is coupled with tissue repair and regeneration process. The canonical Wnt signaling transduction pathway is crucial for cell proliferation, cell differentiation, and tissue regeneration. Dickkopf1 (DKK1) is a quintessential Wnt antagonist that inhibits the Wnt-mediated tissue repair process. Recent studies reported increased levels of DKK1 in many diseases such as cancer, infection, and musculoskeletal diseases. In many cases, the role of DKK1 has been identified as a pro-inflammatory ligand and the expression levels are associated with poor disease outcomes. A variety of cell types including platelets, endothelial cells, and cancer cells secrete DKK1 upon stimuli. This puts DKK1 in a unique place to view immune responses from multicellular interactions in tissue injury and repair process. In this review, we discuss recent efforts to address the underlying mechanism regarding the pro-inflammatory role of DKK1 in cancer, bone diseases, and other inflammatory diseases.

Aberrant expression of genes associated with stemness and cancer in endometria and endometrioma in a subset of women with endometriosis

STUDY QUESTION

Is there molecular evidence for a link between endometriosis and endometriosis-associated ovarian cancers (EAOC)?

STUDY ANSWER

We identified aberrant gene expression signatures associated with malignant transformation in a small subgroup of women with ovarian endometriosis.

WHAT IS KNOWN ALREADY

Epidemiological studies have shown an increased risk of EAOC in women with ovarian endometriosis. However, the cellular and molecular changes leading to EAOC are largely unexplored.

STUDY DESIGN, SIZE, DURATION

CD73+CD90+CD105+ multipotent stem cells/progenitors (SC cohort) were isolated from endometrium (n = 18) and endometrioma (n = 11) of endometriosis patients as well as from the endometrium of healthy women (n = 14). Extensive phenotypic and functional analyses were performed in vitro on expanded multipotent stem cells/progenitors to confirm their altered characteristics. Aberrant gene signatures were also validated in paired-endometrium and -endometrioma tissue samples from another cohort (Tissue cohort, n = 19) of endometriosis patients.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Paired-endometrial and -endometriotic biopsies were obtained from women with endometriosis (ASRM stage III-IV) undergoing laparoscopic surgery. Control endometria were obtained from healthy volunteers. Isolated CD73+CD90+CD105+ SC were evaluated for the presence of known endometrial surface markers, colony forming efficiency, multi-lineage differentiation, cell cycle distribution and 3D-spheroid formation capacity. Targeted RT-PCR arrays, along with hierarchical and multivariate clustering tools, were used to determine both intergroup and intragroup gene expression variability for stem cell and cancer-associated markers, in both SC+ and tissue cohorts.

MAIN RESULTS AND THE ROLE OF CHANCE

Isolated and expanded SC+ from both control and patient groups showed significantly higher surface expression of W5C5+, clonal expansion and 3D-spheroid formation capacity (P < 0.05) compared with SC-. The SC+ cells also undergo mesenchymal lineage differentiation, unlike SC-. Gene expression from paired-endometriosis samples showed significant downregulation of PTEN, ARID1A and TNFα (P < 0.05) in endometrioma compared with paired-endometrium SC+ samples. Hierarchical and multivariate clustering from both SC+ and tissue cohorts together identified 4 out of 30 endometrioma samples with aberrant expression of stem cell and cancer-associated genes, such as KIT, HIF2α and E-cadherin, altered expression ratio of ER-β/ER-α and downregulation of tumour suppressor genes (PTEN and ARID1A). Thus, we speculate that above changes may be potentially relevant to the development of EAOC.

LARGE-SCALE DATA

N/A.

LIMITATIONS, REASON FOR CAUTION

As the reported frequency of EAOC is very low, we did not have access to those samples in our study. Moreover, by adopting a targeted gene array approach, we might have missed several other potentially-relevant genes associated with EAOC pathogenesis. The above panel of markers should be further validated in archived tissue samples from women with endometriosis who later in life developed EAOC.

WIDER IMPLICATIONS OF THE FINDINGS

Knowledge gained from this study, with further confirmation on EAOC cases, may help in developing screening methods to identify women with increased risk of EAOC.

STUDY FUNDING/COMPETING INTEREST(S)

The study is funded by the Swedish Research Council (2012-2844), a joint grant from Stockholm County and Karolinska Institutet (ALF), RGD network at Karolinska Institutet, Karolinska Institutet for doctoral education (KID), Estonian Ministry of Education and Research (IUT34-16), Enterprise Estonia (EU48695), Horizon 2020 innovation program (WIDENLIFE, 692065), European Union's FP7 Marie Curie Industry-Academia Partnerships and Pathways funding (IAPP, SARM, EU324509) and MSCA-RISE-2015 project MOMENDO (691058). All authors have no competing interest.

Current Status of Patient-Derived Ovarian Cancer Models

Ovarian cancer (OC) is one of the leading causes of female cancer death. Recent studies have documented its extensive variations as a disease entity, in terms of cell or tissue of origin, pre-cancerous lesions, common mutations, and therapeutic responses, leading to the notion that OC is a generic term referring to a whole range of different cancer subtypes. Despite such heterogeneity, OC treatment is stereotypic; aggressive surgery followed by conventional chemotherapy could result in chemo-resistant diseases. Whereas molecular-targeted therapies will become shortly available for a subset of OC, there still remain many patients without effective drugs, requiring development of groundbreaking therapeutic agents. In preclinical studies for drug discovery, cancer cell lines used to be the gold standard, but now this has declined due to frequent failure in predicting therapeutic responses in patients. In this regard, patient-derived cells and tumors are gaining more attention in precise and physiological modeling of in situ tumors, which could also pave the way to implementation of precision medicine. In this article, we comprehensively overviewed the current status of various platforms for patient-derived OC models. We highly appreciate the potentials of organoid culture in achieving high success rate and retaining tumor heterogeneity.

Combination of Scoring Criteria and Whole Exome Sequencing Analysis of Synchronous Endometrial and Ovarian Carcinomas

OBJECTIVES

The purpose of this study was to distinguish synchronous primary endometrial and ovarian carcinomas from single primary tumor with metastasis by clinical pathologic criteria and whole exome sequencing (WES).

MATERIAL AND METHODS

Fifty-two patients with synchronous endometrial and ovarian carcinomas (SEOCs) between 2010 and 2017 were reviewed and subjected to WES.

RESULTS

On the basis of the Scully criteria, 11 cases were supposed as synchronous primary endometrial and ovarian carcinomas, 38 cases as single primary tumor with metastasis, and the remaining 3 cases (S50-S52) cannot be defined. Through a quantization scoring analysis, 9 cases that were scored 0-1 point were defined as synchronous primary endometrial and ovarian carcinomas, and 42 cases that were scored 3-8 points were defined as single primary tumor with metastasis. Two of the undefined cases were classified into metastatic disease, and another one that scored 2 points (S52) was subjected to WES. S52 was deemed synchronous primary endometrial and ovarian carcinomas, with few shared somatic mutations and overlapping copy number varieties. The finding of a serous component examined from the uterine endometrium samples further illustrated that the case was synchronous primary endometrial and ovarian carcinomas.

CONCLUSION

By scoring criterion, SEOCs were divided into 2 groups: synchronous primary endometrial and ovarian carcinoma group and single primary tumor with metastasis group. The analysis of clonality indicated that the case that scored 2 (S52) can be considered as synchronous primary endometrial and ovarian carcinomas. Scoring criteria of clinical pathology, along with the study of the WES, may further identify the classification of SEOCs.

Epithelial to Mesenchymal Transition and Cell Biology of Molecular Regulation in Endometrial Carcinogenesis

Endometrial carcinogenesis is involved in several signaling pathways and it comprises multiple steps. The four major signaling pathways-PI3K/AKT, Ras/Raf/MEK/ERK, WNT/β-catenin, and vascular endothelial growth factor (VEGF)-are involved in tumor cell metabolism, growth, proliferation, survival, and angiogenesis. The genetic mutation and germline mitochondrial DNA mutations also impair cell proliferation, anti-apoptosis signaling, and epithelial⁻mesenchymal transition by several transcription factors, leading to endometrial carcinogenesis and distant metastasis. The PI3K/AKT pathway activates the ransforming growth factor beta (TGF-β)-mediated endothelial-to-mesenchymal transition (EMT) and it interacts with downstream signals to upregulate EMT-associated factors. Estrogen and progesterone signaling in EMT also play key roles in the prognosis of endometrial carcinogenesis. In this review article, we summarize the current clinical and basic research efforts regarding the detailed molecular regulation in endometrial carcinogenesis, especially in EMT, to provide novel targets for further anti-carcinogenesis treatment.

High-grade Endometrioid Carcinoma of the Ovary: A Clinicopathologic Study of 30 Cases

Although infrequently encountered, the diagnosis of ovarian high-grade endometrioid carcinoma remains a diagnostic challenge with potential consequences for targeted therapies and genetic counselling. We studied the clinical, morphologic, and immunohistochemical features of ovarian high-grade endometrioid carcinomas and their diagnostic reproducibility compared with tuboovarian high-grade serous carcinomas. Thirty cases confirmed as International Federation of Gynecology and Obstetrics grade 3 endometrioid carcinomas were identified from 182 ovarian endometrioid carcinomas diagnosed in Alberta, Canada, between 1978 and 2010, from the population-based Alberta Ovarian Tumor Types cohort. Cases of lower grade endometrioid and high-grade serous carcinoma served for comparison. Ten immunohistochemical markers were assessed on tissue microarrays. Clinical data were abstracted and survival analyses performed using Cox regression. Interobserver reproducibility for histologic type was assessed using 1 representative hematoxylin and eosin-stained slide from 25 randomly selected grade 3 endometrioid carcinomas and 25 high-grade serous carcinomas. Histotype was independently assigned by 5 pathologists initially blinded to immunohistochemical WT1/p53 status, with subsequent reassessment unblinded to WT1/p53 status. Patients diagnosed with grade 3 endometrioid carcinoma had a significantly longer survival compared with high-grade serous carcinoma in univariate analysis (hazard ratio [HR]=0.34, 95% confidence interval [CI]=0.16-0.67, P=0.0012) but not after adjusting for age, stage, treatment center, and residual tumor (HR=1.01, 95% CI=0.43-2.16, P=0.98). Grade 3 endometrioid carcinoma cases (N=30) were identical to grade 2 endometrioid carcinoma cases (N=23) with respect to survival in univariate analysis (HR=1.07, 95% CI=0.39-3.21, P=0.89) and immunohistochemical profile. Using histomorphology alone, interobserver agreement for the diagnosis of grade 3 endometrioid or high-grade serous carcinoma was 69%, which significantly increased (P<0.0001) to 96% agreement with the knowledge of WT1/p53 status. Our data support the diagnostic value of WT1/p53 status in differentiating between grade 3 endometrioid carcinoma and high-grade serous carcinoma. However, grade 3 and grade 2 endometrioid carcinomas showed no differences in immunophenotype or clinical parameters, suggesting that they could be combined into a single group.

Mechanisms of PTEN loss in cancer: It's all about diversity

PTEN is a phosphatase which metabolises PIP₃, the lipid product of PI 3-Kinase, directly opposing the activation of the oncogenic PI3K/AKT/mTOR signalling network. Accordingly, loss of function of the PTEN tumour suppressor is one of the most common events observed in many types of cancer. Although the mechanisms by which PTEN function is disrupted are diverse, the most frequently observed events are deletion of a single gene copy of PTEN and gene silencing, usually observed in tumours with little or no PTEN protein detectable by immunohistochemistry. Accordingly, with the exceptions of glioblastoma and endometrial cancer, mutations of the PTEN coding sequence are uncommon (<10%) in most types of cancer. Here we review the data relating to PTEN loss in seven common tumour types and discuss mechanisms of PTEN regulation, some of which appear to contribute to reduced PTEN protein levels in cancers.

Molecular association of functioning stroma with carcinoma cells in the ovary: A preliminary study

The cancer stroma serves an important role in tumour behaviours, including invasion, metastasis, and response to chemotherapy. The stroma of ovarian carcinoma is sometimes specialized, with luteinisation and/or hyperthecosis, and is designated as the 'functioning stroma' because it exerts endocrine function and produces sex steroid hormones. In the present study, 14 ovarian cancers with functioning stroma, comprising 7 endometrioid carcinomas and 7 clear cell carcinomas, were analysed to evaluate the molecular association of the functioning stroma with carcinoma cells. The median age of the patients was 67 years (range, 52-85 years); 13 patients were postmenopausal, and one was in perimenopause. Serum oestrogen values ranged from 10 to 129 ng/ml, with a median of 51 ng/ml. Sequence abnormalities in AT-rich interaction domain 1A (ARID1A), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA), Kirsten rat sarcoma viral proto-oncogene (KRAS) and phosphatase and tensin homolog (PTEN) were examined in whole tumours. For cancers positive for sequence abnormalities, their localization in carcinoma cells and/or stromal cells was examined. A total of 8 mutations - ARID1A (L2155L), PIK3CA (H1047R), KRAS (Q12V, E31K, Q61L), and PTEN (C105fs*8) - were identified in the whole tumours of 5 patients. Seven of these eight mutations were detected only in carcinoma cells. However, one case of endometrioid carcinoma had a KRAS (E31K) mutation in both carcinoma and stromal cells. In conclusion, although functioning stromal cells of ovarian cancer are usually thought to be non-neoplastic, some may share an origin with carcinoma cells.