High-grade Endometrioid Carcinoma Research Articles

Ovarian carcinoma: pathology review with an emphasis in their molecular characteristics.

Ovarian carcinoma is highly aggressive and difficult to treat neoplasm, which is usually detected in advanced stages where most patients recur. Extensive investigation about several treatment modalities has been performed but this neoplasm has poor benefits from such treatments including targeted therapy. Recent data have begun to highlight the histological and molecular heterogeneity of these tumors defining this neoplasm, not as a single disease but a group of heterogeneous histological subtypes with important differences in terms of genetics, morphology, oncogenesis, prognosis, chemosensitivity and especially molecular characteristics that are likely to be targets of new molecules. In general, high-grade serous carcinomas are characterized by great genomic instability and frequent amplifications and deletions; lowgrade ovarian neoplasms are genomically stable. On this phytopathogenic basis, recent findings suggest a dual model of carcinogenesis consisting of two large groups named types I and II. Type I cancers (serous, mucinous, and low-grade endometrioid) commonly arise from well-described, genetically stable precursor lesions (usually borderline tumors); manifests as large adnexal masses with the early-stage disease, and they have a good overall prognosis. In contrast, type II carcinomas (serous, high-grade endometrioid, mixed, and undifferentiated carcinomas) originate de novo from the adnexal epithelium, often demonstrate chromosomal instability, and have aggressive biological behavior. Surprisingly, most of the genomic abnormalities detected encode known oncogenic proteins for which there is targeted therapy. Then, there is a real potential for personalized medicine adapted to the molecular portrait of tumors. In this review, I synthesize the histology and molecular pathology of ovarian carcinomas and possible strategies to reach targeted therapy.

Current and future strategies for treatment of ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (OCCC) is one of the five histological types of epithelial ovarian cancer (EOC). OCCC comprises 23% of all EOC cases in Japan, whereas the rate of OCCC in North America and Europe is much lower. OCCC is generally categorized as a rare gynecologic malignancy, and there is limited evidence for specific treatment. The clinical basis for treatment of OCCC is mostly based on retrospective studies, many of which were performed in Japan. Until recently, most randomized clinical trials for EOC have included OCCC; therefore, current treatment for OCCC is basically the same as that for other histologic types of EOC. However, the clinical characteristics of OCCC differ from those of high-grade serous carcinoma, particularly for chemosensitivity, and there is a need to develop new treatment for OCCC. The molecular background of OCCC has unique features: tumors are usually negative for p53 mutations and positive for ARID1A and/or PIK3CA mutations, whereas p53 mutations are common in high-grade serous or endometrioid carcinomas. These features may help in development of new treatment for OCCC. In this review, we described the current evidence for treatment of OCCC, including surgery, radiotherapy, chemotherapy, molecular targeted therapy and immunotherapy, and we discuss ongoing clinical trials and preclinical studies of new treatment approaches for OCCC.

Endometrial Carcinomas with a "Serous" Component in Young Women Are Enriched for DNA Mismatch Repair Deficiency, Lynch Syndrome, and POLE Exonuclease Domain Mutations.

Endometrial carcinoma (EC), as described by Bokhman, has historically been classified as Type I (low-grade, hormone-dependant, young patients, good prognosis) or Type II (high-grade, hormone-independent, older patients, poor prognosis). This classification is no longer pragmatic, however, as EC is a much more heterogeneous disease. Four molecular subtypes of EC were identified by The Cancer Genome Atlas (TCGA), and subsequent studies have demonstrated its utility in predicting prognosis. While endometrial serous carcinoma (ESC), the prototypical Type II EC, largely occurs in older women, younger women with ESC were not accounted for in the Bokhman model and were underrepresented in the TCGA study. We hypothesized that a subset of ESCs in young patients do not represent bona fide serous carcinomas but rather high-grade endometrioid carcinomas mimicking a serous phenotype. We identified ESCs and mixed endometrioid/serous carcinomas in women <60 years (n=37), and analyzed their clinical, morphologic, immunohistochemical, and molecular characteristics. Sixteen percent showed mismatch repair deficiency (MMR-D) and 11% were diagnosed with Lynch syndrome. Additionally, 16% of cases tested harbored a hotspot POLE exonuclease domain mutation (POLE-EDM). Morphologically, 47% of tumors showed confirmatory endometrioid features, including atypical hyperplasia, a low-grade endometrioid carcinoma component, or squamous differentiation. Clinically, the overall survival in patients with MMR-D and POLE-EDM was significantly better than that of patients without these features (P=0.0329). In conclusion, ESCs in young patients comprise a heterogeneous group of tumors, demonstrating diverse clinical, immunohistochemical, morphologic, and molecular features which have implications for prognosis and adjuvant therapy.

High-grade endometrial cancer survival (endometrioid to non-endometrioid histology comparison)

Purpose of Investigation: To analyze overall survival (OS) and disease-free survival (DFS) in a retrospective series of 125 patients with serous, clear cell, and high-grade endometrioid carcinoma having undergone complete treatment (primary surgery, oncology treatments, and follow up) at the present institution. Materials and Methods: All women with high-grade endometrial cancer having undergone surgery (1998-2012) and postoperatively treated and monitored at Split University Hospital Center, whose tissue samples were stored at Department of Pathology, Split University Hospital Center, were included in the study. Survival time was analyzed with Kaplan-Meier method and the log-rank test was used to assess between-group differences. Cox proportional hazard regression model was used on multivariate survival analysis. Patients were followed from the time of primary surgery until death or last follow up in December 2015. Results: Women with serous and clear cell endometrial cancer had similar survival compared to those with high-grade endometrioid endometrial cancer. On multivariate analysis, only earlier stage was an independent predictor of improved survival. Conclusions: The present findings suggest that serous and clear cell endometrial carcinomas have a similar prognosis compared to high-grade endometrioid carcinoma of the uterus.

Unique Molecular Features in High-Risk Histology Endometrial Cancers.

Endometrial cancer is the most common gynecologic malignancy in the United States and the sixth most common cancer in women worldwide. Fortunately, most women who develop endometrial cancer have low-grade early-stage endometrioid carcinomas, and simple hysterectomy is curative. Unfortunately, 15% of women with endometrial cancer will develop high-risk histologic tumors including uterine carcinosarcoma or high-grade endometrioid, clear cell, or serous carcinomas. These high-risk histologic tumors account for more than 50% of deaths from this disease. In this review, we will highlight the biologic differences between low- and high-risk carcinomas with a focus on the cell of origin, early precursor lesions including atrophic and proliferative endometrium, and the potential role of stem cells. We will discuss treatment, including standard of care therapy, hormonal therapy, and precision medicine-based or targeted molecular therapies. We will also discuss the impact and need for model systems. The molecular underpinnings behind this high death to incidence ratio are important to understand and improve outcomes.

Relationship between Microsatellite Instability, Immune Cells Infiltration, and Expression of Immune Checkpoint Molecules in Ovarian Carcinoma: Immunotherapeutic Strategies for the Future.

Ovarian cancer has the worst prognosis among gynecological cancers. Thus, new ovarian cancer treatment strategies are needed. Currently, immune checkpoint inhibitors such as anti-PD-1/PD-L1 antibody are attracting attention worldwide. The Food and Drug Administration approved the use of the PD-1 antibody pembrolizumab for solid cancers with microsatellite instability (MSI)-H or mismatch repair (MMR) deficiency in 2017. However, few studies on ovarian carcinoma have evaluated the relationship among MSI status, lymphocyte infiltration into the tumor, and the expression of immune checkpoint molecules by histologic type. We evaluated the expression of MMR proteins, tumor-infiltrating lymphocytes (CD8+), and immune checkpoint molecules (PD-L1/PD-1) by immunohistochemistry in 136 ovarian cancer patients (76, 13, 23, and 24 cases were high-grade serous, mucinous, endometrioid, and clear cell carcinoma, respectively) to investigate the effectiveness of immune checkpoint inhibitors. Only six cases (4.4%) had loss of MMR protein expression. There was no significant relationship between MSI status and age (p = 0.496), FIGO stage (p = 0.357), initial treatment (primary debulking surgery [PDS] or neoadjuvant chemotherapy) (p = 0.419), residual tumor after PDS or interval debulking surgery (p = 0.202), and expression of CD8 (p = 0.126), PD-L1 (p = 0.432), and PD-1 (p = 0.653). These results suggest that only a small number of MSI cases in ovarian cancer can be effectively treated with immune checkpoint inhibitor monotherapy. Therefore, to improve the prognosis of ovarian carcinoma, a combination therapy of immune checkpoint inhibitors and other anticancer drugs is necessary.

1009P - Incidence of tumour BRCA1/2 variants in relapsed, platinum-sensitive ovarian, fallopian tube and primary peritoneal cancer

BackgroundRandomised phase 3 trials have demonstrated that poly (ADP-ribose) polymerase (PARP) inhibitors significantly improve progression-free survival in BRCA-mutant high-grade serous and endometrioid ovarian carcinoma. Consequently, the demand for germline and tumour BRCA1/2testing has increased significantly throughout the UK. We report results from a tumour BRCA1/2testing service available to cancer centres across England, Wales and Northern Ireland from July 2017 to February 2019. MethodsDNA extracted from formalin fixed, paraffin-embedded tumour samples underwent next generation sequencing for BRCA1/2 variants. Eligibility criteria included relapsed, platinum-sensitive ovarian, fallopian tube or primary peritoneal cancer with germline BRCA1/2wild-type or unknown germline. Patients also had to have received ≥2 prior lines of platinum-based chemotherapy. A confirmatory histopathology report was requested as part of the tumour BRCA1/2testing service. ResultsTwo hundred and ninety-three histologically-confirmed high-grade serous and/or endometrioid ovarian cancer tumour samples underwent tumour BRCA1/2testing. The prevalence of pathogenic (class 5) or likely pathogenic (class 4) variants was 17.7% (52/293). The germline BRCA1/2was wild-type for 185/293 (63.1%) of patients, with the remaining 36.9% (108/293) with germline BRCA1/2unknown. There were at least 36 (12.3%) pathogenic/likely pathogenic somatic BRCA1/2variants detected. The allele fraction for somatic BRCA1/2pathogenic variants ranged from 0.06 to 0.98, with 50% (18/36) reported with an allele fraction of≥0.5 (50%), in keeping with putative biallelic loss-of-function. ConclusionsProspective evaluation of paired germline and tumour BRCA1/2testing in all women who are diagnosed with platinum-sensitive high-grade serous and/or endometrioid ovarian cancer in the UK is now required to validate these findings. Legal entity responsible for the studyAstraZeneca. FundingAstraZeneca. DisclosureAll authors have declared no conflicts of interest.

Detection of POLE Subtypes in High-Grade Endometrioid Carcinoma by BaseScope-ISH Assay.

Objective: The identification of DNA polymerase epsilon (POLE) mutation subtypes in endometrial cancer is critical for molecular classification. The mutation of the POLE gene could only be detected by sequencing until now. We propose to validate and develop the feasibility of using BaseScope, an in situ hybridization (ISH) assay, for the detection of POLE mutations in high-grade endometrioid carcinomas (EC).Methods: Among 51 paraffin-embedded samples of high-grade EC, BaseScope-ISH assays were used to detect the RNA mutation status of the POLE gene, mainly focusing on two hotspot mutations of P286R and V411L. The number of positive signals in the cytoplasm was counted, setting the positive threshold and determining the in situ hybridization results. The sensitivity and specificity of BaseScope-ISH assay were compared with that of the Sanger sequencing results.Results: Based on the BaseScope assay, there were 19 positive samples and 32 negative samples in a total of 51 samples. Of the 19 positive samples, 10 samples showed P286R site mutations in the POLE gene, while the other nine samples were V411L site mutations. Only one sample with the V411L site mutation identified by Sanger sequencing showed negative signal value. The remaining 31 cases without the P286R site mutation or V411L site mutations all showed negative signal. This analysis result showed the sensitivity was 95% and the specificity was 100% for the BaseScope assay detecting POLE mutants in high-grade EC.Conclusion: In the case of high-grade EC, combined with morphological characteristics, the BaseScope assay can effectively and specifically identify POLE mutation cases, providing a reliable foundation for the application of clinical diagnosis and molecular classification.

Use of adjuvant therapy and overall survival in stage II low-grade versus high-grade endometrioid endometrial carcinomas: A National Cancer Database study

Objective: With the recent data demonstrating molecular similarities between some high-grade endometrioid EC (EEC) and serous carcinomas, some practitioners are favoring the use of more aggressive adjuvant therapy than what has historically been used in the treatment of low-grade EEC. The purpose of this study was to ascertain the differences in treatment patterns and outcomes in patients with low-grade and high-grade EEC.

Prevalence of germline pathogenic BRCA1/2 variants in sequential epithelial ovarian cancer cases

IntroductionPoly(ADP-ribose) polymerase inhibitors significantly improve progression-free survival in platinum-sensitive high-grade serous and endometrioid ovarian carcinoma, with greatest benefits observed in women with a pathogenic BRCA1/2 variant. Consequently, the demand for...

High-grade Endometrial Carcinomas: Morphologic and Immunohistochemical Features, Diagnostic Challenges and Recommendations.

This review of challenging diagnostic issues concerning high-grade endometrial carcinomas is derived from the authors’ review of the literature followed by discussions at the Endometrial Cancer Workshop sponsored by the International Society of Gynecological Pathologists in 2016. Recommendations presented are evidence-based, insofar as this is possible, given that the levels of evidence are weak or moderate due to small sample sizes and nonuniform diagnostic criteria used in many studies. High-grade endometrioid carcinomas include FIGO grade 3 endometrioid carcinomas, serous carcinomas, clear cell carcinomas, undifferentiated carcinomas, and carcinosarcomas. FIGO grade 3 endometrioid carcinoma is diagnosed when an endometrioid carcinoma exhibits >50% solid architecture (excluding squamous areas), or when an architecturally FIGO grade 2 endometrioid carcinoma exhibits marked cytologic atypia, provided that a glandular variant of serous carcinoma has been excluded. The most useful immunohistochemical studies to make the distinction between these 2 histotypes are p53, p16, DNA mismatch repair proteins, PTEN, and ARID1A. Endometrial clear cell carcinomas must display prototypical architectural and cytologic features for diagnosis. Immunohistochemical stains, including, Napsin A and p504s can be used as ancillary diagnostic tools; p53 expression is aberrant in a minority of clear cell carcinomas. Of note, clear cells are found in all types of high-grade endometrial carcinomas, leading to a tendency to overdiagnose clear cell carcinoma. Undifferentiated carcinoma (which when associated with a component of low-grade endometrioid carcinoma is termed “dedifferentiated carcinoma”) is composed of sheets of monotonous, typically dyscohesive cells, which can have a rhabdoid appearance; they often exhibit limited expression of cytokeratins and epithelial membrane antigen, are usually negative for PAX8 and hormone receptors, lack membranous e-cadherin and commonly demonstrate loss of expression of DNA mismatch repair proteins and SWI-SNF chromatin remodeling proteins. Carcinosarcomas must show unequivocal morphologic evidence of malignant epithelial and mesenchymal differentiation.

The Effect of Histological Subtypes on Outcomes of Stage IV Epithelial Ovarian Cancer.

Introduction: To examined survival outcome by histological subtypes in de novo stage IV epithelial ovarian cancer (EOC).Methods: Between 2004 and 2015, patients with stage IV EOC were included using the Surveillance, Epidemiology, and End Results program. The effects of histological subtypes on overall survival (OS) were assessed using Kaplan–Meier and multivariable Cox regression analyses.Results: We identified 5,953 patients including 5,351 (89.9%), 249 (4.2%), 145 (2.4%), and 208 (3.4%) patients with high-grade serous, endometrioid, mucinous, and clear cell subtypes, respectively. The 5-year OS rates were 28.1, 38.6, 14.2, and 18.8% in patients with high-grade serous, endometrioid, mucinous, and 18.8% clear cell subtypes, respectively, (p < 0.001). Multivariate analyses indicated that histological subtype was an independent predictor of OS. Using the high-grade serous subtype as a reference, OS was comparable for the endometrioid subtype (hazard ratio (HR) 0.915, 95% confidence interval) (CI 0.772–1.085, p = 0.305), but significantly lower for mucinous (HR 3.292, 95% CI 2.701–4.011, p < 0.001) and clear cell subtypes (HR 1.820, 95% CI 1.546–2.141, p < 0.001). Patients with no residual tumor had better OS in the high-grade serous and endometrioid subtypes compared to patients with residual tumors. However, the residual tumor size was not a prognostic factor for OS in mucinous and clear cell carcinoma.Conclusions: Our study suggest a markedly mortality rate in patients with stage IV mucinous and clear cell carcinoma, but better survival in patients with high-grade serous and endometrioid subtypes. Aggressive radical surgery to leave no residual disease would improve survival for high-grade serous and endometrioid carcinoma. More studies are needed to assess the value of aggressive radical surgery in patients with mucinous and clear cell subtypes.

Molecular Genetics of Endometrial Carcinoma.

Endometrial cancer is the most commonly diagnosed gynecologic malignancy in the United States. Endometrioid endometrial carcinomas constitute approximately 85% of newly diagnosed cases; serous carcinomas represent approximately 3-10% of diagnoses; clear cell carcinoma accounts for <5% of diagnoses; and uterine carcinosarcomas are rare, biphasic tumors. Longstanding molecular observations implicate PTEN inactivation as a major driver of endometrioid carcinomas; TP53 inactivation as a major driver of most serous carcinomas, some high-grade endometrioid carcinomas, and many uterine carcinosarcomas; and inactivation of either gene as drivers of some clear cell carcinomas. In the past decade, targeted gene and exome sequencing have uncovered additional pathogenic aberrations in each histotype. Moreover, an integrated genomic analysis by The Cancer Genome Atlas (TCGA) resulted in the molecular classification of endometrioid and serous carcinomas into four distinct subgroups, POLE (ultramutated), microsatellite instability (hypermutated), copy number low (endometrioid), and copy number high (serous-like). In this review, we provide an overview of the major molecular features of the aforementioned histopathological subtypes and TCGA subgroups and discuss potential prognostic and therapeutic implications for endometrial carcinoma.

Histotype classification of ovarian carcinoma: A comparison of approaches

ObjectiveMajor changes in the classification of ovarian carcinoma histotypes occurred over the last two decades, resulting in the current 2014 World Health Organization (WHO) diagnostic criteria that recognize five principal histotypes: high-grade serous, low-grade serous, endometrioid, clear cell, and mucinous carcinoma. We assessed the impact of these guidelines and use of immunohistochemical (IHC) markers on classification of ovarian carcinomas in existing population-based studies. MethodsWe evaluated histotype classification for 2361 ovarian carcinomas diagnosed between 1999 and 2009 from two case-control studies using three approaches: 1. pre-2014 WHO (“historic”) histotype; 2. Standardized review of pathology slides using the 2014 WHO criteria alone; and 3. An integrated IHC assessment along with the 2014 WHO criteria. We used Kappa statistics to assess agreement between approaches, and Kaplan-Meier survival curves and Cox proportional hazards models to evaluate mortality. ResultsCompared to the standardized pathologic review histotype, agreement across approaches was high (kappa = 0.892 for historic, and 0.849 for IHC integrated histotype), but the IHC integrated histotype identified more low-grade serous carcinomas and a subset of endometrioid carcinomas that were assigned as high-grade serous (n = 25). No substantial differences in histotype-specific mortality were observed across approaches. ConclusionsOur findings suggest that histotype assignment is fairly consistent regardless of classification approach, but that progressive improvements in classification accuracy for some less common histotypes are achieved with pathologic review using the 2014 WHO criteria and with IHC integration. We additionally recommend a classification scheme to fit historic data into the 2014 WHO categories to answer histotype-specific research questions.

Sexual steroid hormone receptors profiles of ovarian carcinoma in Mexican women.

The significance of the presence of androgen receptor (AR), estrogen receptor alpha (ER) and progesterone receptor (PR) in ovarian cancer patient survival has been a matter of numerous studies. This study was aimed to describe the expression profile of the three sexual steroid receptors in high-grade serous, endometrioid, mucinous and low-grade serous ovarian carcinoma and its association to the proliferation index in patients with primary ovarian carcinoma diagnosis, before any treatment. Eighty-one samples were obtained from the National Institute of Cancerology in Mexico City and were evaluated for the presence of AR, ER, PR and Ki67 by immunohistochemistry. The four subtypes of ovarian carcinoma displays a specific profile of the eight possible combinations of the steroid receptors with significant differences within the profile and the histological subtypes. High-grade serous carcinoma was characterized by a high frequency of both, triple-negative and AR+ ER− PR+ profiles. Endometrioid carcinoma presented a higher frequency of triple-positive profile. The presence of only AR+ profile was not observed in the endometrioid tumors. The relationship of the receptor profile with the proliferation index in the tumor epithelium shows that the expression of only ER is associated to a reduced proliferation index in endometrioid carcinoma. Steroid hormone receptor expression and co-expression could help characterize ovarian carcinoma.

Ovarian carcinomas: at least five different diseases with distinct histological features and molecular genetics

Based on histopathology and molecular genetics, ovarian carcinomas are divided into five main types: high-grade serous (70%), endometrioid (10%), clear cell (10%), mucinous (3%), and low-grade serous (<5%) carcinomas. These tumors, which account for over 95% of cases, represent distinct diseases with different prognoses and treatments. TP53 mutations are identified in almost all (96%) high-grade serous carcinomas (HGSCs). Early p53 loss followed by BRCA loss leads to deficiency in homologous recombination (DHR) repair, which in turn triggers chromosomal instability and widespread somatic copy number changes. An undetermined number of cases of HGSCs originate in the tubal fimbria; however, an origin from the ovarian surface epithelium cannot be totally excluded. Low-grade serous carcinomas (LGSCs) most likely represent progression of SBTs. BRAF or KRAS mutations occur in one-third to one-half of cases. Mucinous carcinomas (MCs) typically show benign-appearing, borderline, non-invasive and invasive components indicating tumor progression. KRAS mutations occur in 43.6% of cases and overexpression/amplification of HER2 in 18.8%. Endometrioid and clear cell carcinomas (EC and CCC) originate from ovarian endometriosis. Compared with their uterine counterparts, ECs have a similar frequency of β-catenin abnormalities but lower rate of microsatellite instability (MI) and PTEN alterations. ARID1A mutations occur in both ECs (30%) and CCCs (50%) and may be encountered in adjacent endometriosis. CCCs carry inactivating PTEN mutations and activating mutations in PIK3CA in 8% and 33% of cases, respectively. This review summarizes recent advances in the molecular pathology, which have greatly improved our understanding of the biology of ovarian carcinomas and are also relevant to patient management.

Myoferlin Expression and Its Correlation with FIGO Histologic Grading in Early-Stage Endometrioid Carcinoma.

BackgroundFor endometrioid carcinoma patients, International Federation of Gynecologists and Obstetricians (FIGO) histologic grading is very important for identifying the appropriate treatment method. However, the interobserver discrepancy with this three-tiered grading system is a serious potential problem. In this study, we used immunohistochemistry to analyze the relationship between FIGO histologic grading score and myoferlin expression. MethodsWe studied the endometrioid carcinoma tissues of 60 patients from Gyeongsang National University Hospital between January 2002 and December 2009. Immunohistochemical analysis of myoferlin was performed on tissue microarray blocks from surgical specimens. ResultsMyoferlin expression was observed in 58 of 60 patients. Moderate and strong myoferlin expression was observed in low-grade endometrioid carcinoma, while there was a tendency toward loss of myoferlin expression in high-grade endometrioid carcinoma (p<.001). ConclusionsOur study revealed that myoferlin loss is significantly correlated with high FIGO grade of endometrioid carcinoma.

Androgen Receptor Expression in Endometrial Carcinoma.

Endometrial carcinoma (ECA) is frequently hormonally driven and can be treated with endocrine-based therapy, yet hormone receptor status is not routinely assessed. In particular, little is known about the significance of androgen receptor (AR) in ECA. Androgen has antiproliferative effects in the healthy endometrium and could serve a similar role to progesterone in curbing the progression of estrogen-dependent neoplasia. There may also be a subset of ECA that benefits from androgen antagonistic therapy. We herein investigate AR expression across ECA subtypes and compare its expression to estrogen receptor (ER) and progesterone receptor (PR). Immunohistochemical staining for AR, ER, and PR was performed on an endometrial tissue microarray containing 50 ECA with a variety of morphologic subtypes as well as 20 benign and 9 atypical hyperplastic endometria. AR was expressed by 54% (27/50) of ECA including 60% of low grade endometrioid carcinomas, 70% high grade endometrioid carcinomas, 70% serous carcinomas, 50% carcinosarcomas, and 20% clear cell carcinomas. High AR expression was chiefly restricted to a subset of serous carcinomas (50%). AR expression occurred most often in concert with ER staining, although 5 high grade cancers (1 serous carcinoma, 4 carcinosarcomas) showed AR expression in the absence of ER. In summary, AR positivity is seen in over half of ECA in our study, including the majority of low grade endometrioid carcinomas, high grade endometrioid carcinomas, and serous carcinomas. High level expression is seen in half of serous carcinomas and a subset of serous carcinomas and carcinosarcomas show some degree of AR staining in the absence of ER, suggesting a possible role for androgen inhibition in treatment of these cases.

Are the uterine serous carcinomas underdiagnosed? Histomorphologic and immunohistochemical correlates and clinical follow up in high-grade endometrial carcinomas initially diagnosed as high-grade endometrioid carcinoma

Histologic subclassification of high-grade endometrial carcinomas can sometimes be a diagnostic challenge when based on histomorphology alone. Here we utilized immunohistochemical markers to determine the immunophenotype in histologically ambiguous high-grade endometrial carcinomas that were initially diagnosed as pure or mixed high-grade endometrioid carcinoma, aiming to determine the utility of selected immunohistochemical panel in accurate classification of these distinct tumor types, while correlating these findings with the clinical outcome. A total of 43 high-grade endometrial carcinoma cases initially classified as pure high-grade endometrioid carcinoma (n=32), mixed high-grade endometrioid carcinoma/serous carcinoma (n=9) and mixed high-grade endometrioid carcinoma/clear cell carcinoma (n=2) were retrospectively stained with a panel of immunostains, including antibodies for p53, p16, estrogen receptor, and mammaglobin. Clinical follow-up data were obtained, and stage-to-stage disease outcomes were compared for different tumor types. Based on aberrant staining for p53 and p16, 17/43 (40%) of the high-grade endometrial carcinoma cases initially diagnosed as high-grade endometrioid carcinoma were re-classified as serous carcinoma. All 17 cases showed negative staining for mammaglobin, while estrogen receptor was positive in only 6 (35%) cases. The remaining 26 cases of high-grade endometrioid carcinoma showed wild-type staining for p53 in 25 (96%) cases, patchy staining for p16 in 20 (77%) cases, and were positive for mammaglobin and estrogen receptor in 8 (31%) and 19 (73%) cases, respectively, thus the initial diagnosis of high-grade endometrioid carcinoma was confirmed in these cases. In addition, the patients with re-classified serous carcinoma had advanced clinical stages at diagnosis and poorer overall survival on clinical follow-up compared to that of the remaining 26 high-grade endometrioid carcinoma cases. These results indicate that selected immunohistochemical panel, including p53, p16, and mammaglobin can be helpful in reaching accurate diagnosis in cases of histomorphologically ambiguous endometrial carcinomas, and can assist in providing guidance for appropriate therapeutic options for the patients.

Prexasertib, a cell cycle checkpoint kinase 1 and 2 inhibitor, in BRCA wild-type recurrent high-grade serous ovarian cancer: a first-in-class proof-of-concept phase 2 study

BackgroundHigh-grade serous ovarian carcinoma (HGSOC) is characterized by TP53 mutations, DNA repair defects, and genomic instability. We hypothesized that prexasertib, a cell cycle checkpoint kinase 1 and 2 inhibitor, would be active in BRCA wild-type HGSOC.MethodsIn this open label, single centre, two-stage proof-of-concept phase 2 study, women aged 18 years or older with measurable, recurrent high-grade serous or high-grade endometrioid ovarian carcinoma were enrolled. All patients must have had either a negative family history of hereditary breast and ovarian cancer or known BRCA wild-type for BRCA wild-type cohort. Other key eligibility criteria were an Eastern Cooperative Oncology Group performance status of 0 or 1 or 2, and adequate haematological, renal, and hepatic function. Patients received intravenous prexasertib 105mg/m2 once every 2 weeks until disease progression, unacceptable toxicity or patient withdrawal of consent. The primary endpoint was investigator-assessed tumour response per protocol based on Response Evaluation Criteria in Solid Tumors, version 1·1 in evaluable patients. The final analysis of this cohort is reported here. This ongoing trial is registered with ClinicalTrials.gov (NCT02203513) and enrolling the patients of BRCA mutation cohort.FindingsBetween January 2015 and November 2016, 28 women (median age 64-year-old [IQR 58–69·5], with median 5 prior systemic therapies [IQR 2·5–5]) were enrolled and received at least one dose of prexasertib. Eight of 24 evaluable patients had a partial response (PR; 33%, 95% CI: 16–55) and 50% had a GCIG CA125 response. The RR in the intention-to-treat population was 29% (8/28, 95% CI: 13–49). The common (>10%) grade 3 or 4 treatment-emergent adverse events were neutropenia (26 [93%] patients), thrombocytopenia (seven [25%] patients), and anaemia (three [11%] patients). Grade 4 neutropenia occurred in 22 (79%) patients after the first dose and was transient ≤ 7 days (median 6 days [IQR 4–8]) without growth factor support; the incidence of febrile neutropenia was 7% (2/28).InterpretationWe demonstrate clinical activity of prexasertib in BRCA wild-type HGSOC, especially patients with platinum-resistant or refractory ovarian cancer. These results warrant further development for this unmet patient need.FundingIntramural Research Program of the National Institutes of Health, National Cancer Institute, Center for Cancer Research, USA.