Serous endometrial intraepithelial carcinoma: a case series and literature review

Special Considerations in Classification and Workup of Endometrial Carcinomas

CONTEXT.—

A variety of uncommon malignant endometrial tumors can be challenging to diagnose because of overlapping morphology with more common entities. In some cases, immunohistochemical stains and/or molecular testing allow for more definitive diagnosis or prognostication.

OBJECTIVE.—

To review classic morphologic features of uncommon endometrial tumors, pathologic features of these tumors and their mimics, and the evidence for use of immunohistochemistry and molecular testing in the diagnosis of these tumors.

DATA SOURCES.—

University of Michigan (Ann Arbor) cases and review of pertinent literature about each entity.

CONCLUSIONS.—

Although each of these uncommon endometrial tumors has morphologic mimics, key histologic features, immunohistochemical stains, and molecular testing allow for accurate classification.

Critical Overview of Serous Endometrial Intraepithelial Cancer Treatment: Systematic Review of Adjuvant Options

SEIC is a non-invasive lesion of the endometrial epithelium considered to be the precursor to uterine serous carcinoma (USC) and is just as aggressive as USC. Currently, there are no reliable data about the behavior and prognosis of SEIC; therefore, the therapeutic management approach is not clear. Method: A systematic search of the Pubmed, Scopus and Embase databases was conducted, following the recommendations in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Results: Of the 296 studies that matched the search criteria, only 9 met the inclusion criteria, covering a total of 81 patients. The main disease-presenting pattern was AUB (abnormal uterine bleeding). In 31 cases, SEIC was associated with extrauterine disease. All patients underwent hysterectomy and salpingo-oophorectomy, while only 15 of the 81 patients received adjuvant treatments. In the patients receiving adjuvant therapy, the RR was 42.67%, the DFS was 35.71% and the OS was 57.13%. In patients subjected to follow-up alone, the RR was only 28.78%, the DFS was 59.1% and the OS was 66.6%. Conclusions: The presence of an extrauterine disease significantly worsens outcomes, regardless of adjuvant treatment. In cases of disease confined to the uterine mucosa alone, the prognosis is good and follow-up allows a good control of the disease; however, adjuvant therapy could further increase survival rates and reduce relapse rates.

Serous endometrial intra-epithelial carcinoma: an observational study

BACKGROUND

Serous endometrial intra-epithelial carcinoma is described as a malignant, superficial spreading lesion with risk of extra-uterine spread at time of diagnosis, and poor outcome.

OBJECTIVE

To evaluate the surgical management of patients with serous endometrial intra-epithelial carcinoma and its impact on oncologic outcomes and complications.

METHODS

This Dutch observational retrospective cohort study evaluated all patients diagnosed with pure serous endometrial intra-epithelial carcinoma in the Netherlands, between January 2012 and July 2020. The pathological examination was reviewed by two pathologists with expertise in gynecological oncology. Clinical data were obtained when the diagnosis was confirmed. Primary outcome is progression-free survival, secondary outcomes are duration of follow-up, adverse events related to surgery, and overall survival.

RESULTS

A total of 23 patients from 13 medical centers were included, of whom 15 (65.2%) presented with post-menopausal blood loss. In 17 patients (73.9%) the intra-epithelial lesion was present in an endometrial polyp. All patients underwent hysterectomy, of whom 12 patients (52.2%) were surgically staged. None of the staged patients showed extra-uterine disease. Two patients received adjuvant brachytherapy. There were no recurrences of disease (median follow-up duration of 35.6 months (range 1.0-108.6) and no disease-related deaths in this cohort.

CONCLUSION

In patients with serous endometrial intra-epithelial carcinoma, median progression-free survival reached nearly 3 years and no recurrences have been reported. Our results do not endorse World Health Organization 2014 advice to treat serous endometrial intra-epithelial carcinoma as high-grade, high-risk endometrial carcinoma. Full surgical staging might possibly lead to overtreatment.

Co-existing TP53 and ARID1A mutations promote aggressive endometrial tumorigenesis

TP53 and ARID1A are frequently mutated across cancer but rarely in the same primary tumor. Endometrial cancer has the highest TP53-ARID1A mutual exclusivity rate. However, the functional relationship between TP53 and ARID1A mutations in the endometrium has not been elucidated. We used genetically engineered mice and in vivo genomic approaches to discern both unique and overlapping roles of TP53 and ARID1A in the endometrium. TP53 loss with oncogenic PIK3CA^H1047R in the endometrial epithelium results in features of endometrial hyperplasia, adenocarcinoma, and intraepithelial carcinoma. Mutant endometrial epithelial cells were transcriptome profiled and compared to control cells and ARID1A/PIK3CA mutant endometrium. In the context of either TP53 or ARID1A loss, PIK3CA mutant endometrium exhibited inflammatory pathway activation, but other gene expression programs differed based on TP53 or ARID1A status, such as epithelial-to-mesenchymal transition. Gene expression patterns observed in the genetic mouse models are reflective of human tumors with each respective genetic alteration. Consistent with TP53-ARID1A mutual exclusivity, the p53 pathway is activated following ARID1A loss in the endometrial epithelium, where ARID1A normally directly represses p53 pathway genes in vivo, including the stress-inducible transcription factor, ATF3. However, co-existing TP53-ARID1A mutations led to invasive adenocarcinoma associated with mutant ARID1A-driven ATF3 induction, reduced apoptosis, TP63+ squamous differentiation and invasion. These data suggest TP53 and ARID1A mutations drive shared and distinct tumorigenic programs in the endometrium and promote invasive endometrial cancer when existing simultaneously. Hence, TP53 and ARID1A mutations may co-occur in a subset of aggressive or metastatic endometrial cancers, with ARID1A loss promoting squamous differentiation and the acquisition of invasive properties.

Endometrial cancer is the most commonly diagnosed gynecologic malignancy in the United States, with annual incidence continuing to rise. Although the majority of endometrial cancer patients have an excellent overall prognosis if the disease is confined to the endometrium, myometrial invasion and metastasis to other sites correlate with poor survival. Here, we used genetically engineered mice, in vivo genomics, and public cancer patient data to understand the relationship between TP53 and ARID1A, two of the most commonly mutated genes in endometrial cancer, in the context of mutant PIK3CA. Mutations in TP53 and ARID1A change different aspects of endometrial cell health but also share some similarities. ARID1A mutations specifically promote cancer cells to invade nearby tissue, a hallmark of metastasis, associated with squamous differentiation. Mice with co-existing TP53 and ARID1A mutations developed more invasive disease. Our studies suggest that co-existing TP53 and ARID1A tumor mutations may promote invasion and metastasis.

Inspection for micrometastasis is essential for predicting the prognosis of serous endometrial intraepithelial carcinoma: Case report and literature review

Serous endometrial intraepithelial carcinoma is the precursor of invasive uterine serous carcinoma. Here, we present two cases of serous endometrial intraepithelial carcinoma with omental micrometastasis and discuss their clinical significance. Two menopausal patients with abnormal endometrial biopsy findings underwent hysterectomy and comprehensive surgical staging (bilateral salpingo-oophorectomy, omentectomy, and pelvic and para-aortic lymphadenectomy). Although gross examination failed to detect tumors, the pathological diagnosis was serous endometrial intraepithelial carcinoma. Both patients had omental micrometastasis; they were diagnosed with International Federation of Gynecology and Obstetrics stage IVB disease and received postoperative chemotherapy. One patient died of the carcinoma 9 months after the hysterectomy, and the other had a recurrence of carcinoma 17 months after the end of the initial therapy. The present cases and literature review highlight the importance of meticulous inspection for micrometastasis in the abdominal cavity, including the omentum and peritoneum, for predicting prognosis.

Serous endometrial intraepithelial carcinoma (SEIC): Current clinical practice in The Netherlands

INTRODUCTION

Serous endometrial intraepithelial carcinoma (SEIC) is a rare diagnosis, defined as an intraepithelial lesion with cells identical to serous type endometrial carcinoma. SEIC is considered to be potentially metastatic, however clear and robust data on prognosis are lacking, potentially leading to variability in clinical management.

OBJECTIVE

The aim is to establish the opinion of gynecologists on the optimal management of patients with SEIC.

METHODS

An online questionnaire with 15 multiple choice questions was sent to all gynecologists with expertise in gynecological oncology in 19 expert centers in The Netherlands.

RESULTS

A total of 24 gynecologists participated. The majority of respondents (n = 18/24, 75%) do not consult a guideline regarding the treatment of SEIC. In current practice, 14 of the 24 respondents perform surgical staging in women with SEIC (58.3%) while seven choose hysterectomy with bilateral salpingo-oophorectomy (29.2%), and three (12.5%) have no firm preference. Eleven of the 14 respondents who perform a surgical staging procedure believe that this is certainly the optimal treatment. The majority of respondents have no firm opinion on whether lymph node sampling or lymph node dissection is preferable during surgical staging (n = 15/23, 65.2%). Most respondents do not give adjuvant therapy (n = 15/24, 62.5%), 25.0% recommend brachytherapy (n = 6/24). Follow-up is for 5 years in almost all cases (n = 23/24).

CONCLUSION

There is no consensus on the optimal surgical treatment and the use of adjuvant therapy for patients with SEIC. Our research team is therefore conducting a nationwide cohort study in which treatment modality, morbidity and survival will be evaluated.

Endometrial carcinoma: molecular subtypes, precursors and the role of pathology in early diagnosis

Endometrial carcinoma (EC) is classified into a wide range of morphological variants; this list has expanded over the past decade with the inclusion of mesonephric-like and dedifferentiated carcinoma as EC variants in the fifth edition of the WHO Classification of Female Genital Tumours, and recognition that carcinosarcoma is a biphasic carcinoma rather than a sarcoma. Each EC variant has distinct molecular abnormalities, including TCGA-based molecular subtypes, allowing further subclassification and adding complexity. In contrast to this rapid progress in understanding EC, there are only two recognized EC precursor lesions: endometrial atypical hyperplasia/endometrioid intraepithelial neoplasia (EAH/EIN) and serous intraepithelial carcinoma, a situation that has not changed for many years. Diagnosis of EC precursors is a cornerstone of surgical pathology practice, with early diagnosis contributing to the relatively favorable prognosis of EC. In this review we relate the precursor lesions to each of the EC morphological variants and molecular subtypes, discuss how successful early diagnosis is for each variant/molecular subtype and how it might be improved, and identify knowledge gaps where there is insufficient understanding of EC histogenesis. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Notch and Endometrial Cancer

The human endometrium is a unique, highly dynamic tissue that undergoes cyclic changes of cell proliferation, differentiation, and death. Endometrial cancer is the most common malignancy among women in developed countries. Importantly, the incidence of endometrial cancer is rising in high-income countries. Currently histological classification is used for subtyping of endometrial cancer, while ongoing research is evaluating markers for more accurate molecular classification. Evolutionary conserved Notch signaling pathway regulates diverse cellular processes such as proliferation, differentiation, and cell invasion. Accumulating evidence links aberrant Notch signaling with diseases such as hyperplasia and endometrial cancer. This chapter summarizes the current state of Notch signaling investigations in the endometrium, endometriosis, and endometrial cancer.

Evaluation of HER2/neu Expression in High-Grade Endometrial Carcinoma and Its Clinicopathological Correlation

Background & Objective:

Endometrial carcinoma (EC) has been traditionally classified into two distinct categories of low-grade and high-grade. Type I (low grade) EC, which constitutes the majority of cases, is linked to estrogen-related molecular pathways. But type II (high-grade) EC accounts for 10-20% of cases and behaves in an aggressive way. Pathologic and biological features of type II EC have not been fully elucidated yet. Several investigations have demonstrated HER2/neu expression and amplification in type II EC, especially papillary serous carcinoma (PSC). This study assessed HER2/neu expression in high-grade EC as well as its association with other clinical and histopathological prognostic factors.

Methods:

In this cross-sectional study, we performed HER2/neu immunohistochemical (IHC) staining in 37 high-grade EC cases with histological diagnostic categories of PSC (n=23), clear cell carcinoma (CCC) (n=9), and carcinosarcoma with high-grade carcinomatous component (PSC, CCC, grade 3 endometrioid carcinoma, or unclassified high-grade adenocarcinoma) (n=5). All patients were followed for 2-9 years in order to evaluate their disease-free survival (DFS) and overall survival (OS) during study period (2005-2014).

Results:

HER2/neu IHC staining was positive in 12 patients (32.4%) including 8/23 (34.8%) PSC, 2/9 (22.2%) CCC, and 2/5 (40%) carcinosarcoma cases. There was no statistically significant difference between HER2/neu expression and DFS or OS of the patients (P>0.05).

Conclusion:

We observed that HER2/neu is expressed in one-third of high-grade ECs. This ancillary test is supportive in follow-up of patients with high-grade ECs.

Classification of Endometrial Carcinoma: New Perspectives Beyond Morphology

Endometrial carcinoma has been traditionally divided into type 1 or endometrioid type that is usually moderate to well differentiated and type 2 that is usually poorly differentiated with high histologic grade and aggressive clinical behavior. However, interobserver diagnostic agreement is suboptimal, particularly among the high-grade histotypes. Furthermore, recent data indicate that this histotype assignment does not independently correlate with survival. In recent years, there has been remarkable progress in our understanding of the molecular basis of endometrial carcinoma and extensive molecular studies have been performed under The Cancer Genome Atlas Program (TCGA) leading to molecular classification of endometrial carcinoma that has been shown to be significantly prognostic. This classification system divides the tumors into 4 subgroups namely, polymerase ε exonuclease (POLE) ultramutated, hypermutated microsatellite instability, copy number low, and copy number high (serous-like). Carcinomas with POLE domain hotspot mutations are highly prognostically favorable; those with copy number alterations and TP53 mutations are highly aggressive; and microsatellite unstable and "copy number low" endometrioid are associated with intermediate prognoses. The TCGA applied methods that are too costly and cumbersome for widespread implementation into routine clinical practice. Several other groups have attempted to identify these categories by using immunohistochemical biomarkers rather than molecular studies. Immunohistochemical biomarkers have been used successfully to identify all the subgroups except for POLE ultramutated, which requires sequencing for proper categorization. It is hoped that future studies will identify a suitable biomarker for POLE mutation so that this classification can be routinely used in all medical centers.

An update on the use of immunohistochemistry and molecular pathology in the diagnosis of pre-invasive and malignant lesions in gynecological oncology

OBJECTIVE

One of the most common challenges in everyday clinical practice of gynecological oncology is to identify the type and the primary origin of a tumor. This is a crucial step in the management, treatment, prognosis, and survival of patients suffering from a gynecological malignancy. Immunohistochemistry has been widely adopted over the last three decades in pathology laboratories all over the world. Recent advances in our understanding of the differentiation of gynecological tumors based on immunohistochemical expression have resulted in use of immunohistochemistry as a major diagnostic tool in gynecology, for precise tumor classification. More recently, advances in molecular pathology, have taken this disease sub-classification further resulting in more effective personalised treatment regimens. The aim of this review is to provide clinicians with up to date information on the various immunohistochemical and molecular tests used in the diagnosis of gynecological malignancies of the female genital tract and an understanding of how to interpret them.

METHODS

We performed a review of the current literature including review articles, original research articles, and guidelines on various immunohistochemical markers and molecular techniques which are used for the differential diagnosis of gynecologic malignancies.

CONCLUSIONS

Immunohistochemistry is useful as an objective means for improved diagnostic reproducibility, accuracy, and precise classification in cases where the diagnosis with histochemical stains is inconclusive, providing a more reliable estimate of clinical outcomes. The diagnosis, in some cases, can be further refined by the use of molecular techniques leading to personalised medical treatments.

Tubal Ligation and Risk of Endometrial Cancer: Findings From the Women's Health Initiative

OBJECTIVE

Bilateral tubal ligation (BTL) is a common form of birth control in the United States. There are limited, contradictory data examining BTL and the risk of endometrial cancer and none examining type I and type II cancers separately. We investigated the association between BTL and endometrial cancer risk using the Women's Health Initiative (WHI) Observational and Dietary Modification Studies.

METHODS

Demographic information and history of BTL were obtained from the baseline questionnaires from 76,483 WHI participants in the Observational and Dietary Modification Studies. Univariable and multivariable models were used to examine the association of BTL with type I and type II endometrial cancers.

RESULTS

A total of 1137 women were diagnosed with incident endometrial cancer (972 type I and 128 type II) during a mean follow-up of 11.3 years. Overall, 14,499 (19%) women had undergone BTL. There were no statistically significant associations noted between BTL and age at BTL for type I or type II cancers.

CONCLUSIONS

We examined the largest patient cohort to date in an effort to determine the impact of BTL on endometrial cancer risk. In the WHI trial, we observed no overall effect of BTL on the risk of type I or type II endometrial cancer, suggesting that patients undergoing this popular birth control method likely do not have an associated change in their baseline risk for endometrial cancer.

Similar protein expression profiles of ovarian and endometrial high-grade serous carcinomas

Background:

Ovarian and endometrial high-grade serous carcinomas (HGSCs) have similar clinical and pathological characteristics; however, exhaustive protein expression profiling of these cancers has yet to be reported.

Methods:

We performed protein expression profiling on 14 cases of HGSCs (7 ovarian and 7 endometrial) and 18 endometrioid carcinomas (9 ovarian and 9 endometrial) using iTRAQ-based exhaustive and quantitative protein analysis.

Results:

We identified 828 tumour-expressed proteins and evaluated the statistical similarity of protein expression profiles between ovarian and endometrial HGSCs using unsupervised hierarchical cluster analysis (P<0.01). Using 45 statistically highly expressed proteins in HGSCs, protein ontology analysis detected two enriched terms and proteins composing each term: IMP2 and MCM2. Immunohistochemical analyses confirmed the higher expression of IMP2 and MCM2 in ovarian and endometrial HGSCs as well as in tubal and peritoneal HGSCs than in endometrioid carcinomas (P<0.01). The knockdown of either IMP2 or MCM2 by siRNA interference significantly decreased the proliferation rate of ovarian HGSC cell line (P<0.01).

Conclusions:

We demonstrated the statistical similarity of the protein expression profiles of ovarian and endometrial HGSC beyond the organs. We suggest that increased IMP2 and MCM2 expression may underlie some of the rapid HGSC growth observed clinically.