Clear cell carcinoma of the endometrium: an immunohistochemical and molecular analysis of 45 cases

Impact of adjuvant therapy on oncologic outcomes in uterine-confined clear cell carcinoma of the endometrium

OBJECTIVES

To determine the impact of adjuvant therapy on oncologic outcomes in patients with 2009 International Federation of Gynecology and Obstetrics (FIGO) stage IA, IB, or II endometrial clear cell carcinoma (ECCC).

METHODS

We conducted a retrospective review at 4 international institutions. Patients with newly diagnosed clinical stage I or II disease of either clear cell or mixed histology with a clear cell component treated between 01/01/2000-12/31/2015 were included. Oncologic outcomes were assessed for patients based on adjuvant treatment received, including chemotherapy, radiation, or chemotherapy with radiation.

RESULTS

Of 125 patients identified and analyzed, 77 (61.6%) had clear cell histology and 118 (94.4%) had stage I disease. Median age at diagnosis was 65 years (range, 33-91). All patients underwent hysterectomy, bilateral salpingo-oophorectomy, and lymph node assessment. Twenty-five patients (20.0%) underwent surgical management alone and 100 (80.0%) received adjuvant therapy: 20 (16.0%) received postoperative chemotherapy, 47 (37.6%) received postoperative radiation, and 33 (26.4%) received postoperative chemotherapy with radiation. Median follow-up was 88.4 months (range, <1-234). Progression-free survival (PFS) or overall survival (OS) did not significantly differ between surgery alone and type of adjuvant therapy (P = 0.18 and P = 0.56, respectively). Patients with mixed ECCC did not have a survival advantage over those with pure ECCC (5-year PFS rate, 85.0% vs 82.7%, P = 0.77; 5-year OS rate, 88.3% vs 91.2%, P = 0.94).

CONCLUSIONS

Receipt of adjuvant therapy in surgically staged I/II ECCC did not appear to offer a survival advantage over observation alone. Adjuvant therapy in early-stage ECCC with consideration of molecular classification should be evaluated.

Long non-coding RNA JPX promotes endometrial carcinoma progression via janus kinase 2/signal transducer and activator of transcription 3

Introduction

Although LncRNA JPX has been linked to a number of malignancies, it is yet unknown how it relates to endometrial carcinoma (EC). Investigating the expression, functional activities, and underlying molecular processes of lncRNA JPX in EC was the goal of this work.

Methods

RT-qPCR was used to examine the differences in lncRNA/microRNA (miRNA, miR)/mRNA expression between normal cervical and EC tissues or cells. Cell Counting Kit-8, flow cytometry, and transwell were used to evaluate the association between lncRNA JPX/miR-140-3p/phosphoinositide-3-kinase catalytic subunit α (PIK3CA) in Ishikawa and JEC cell lines. The impact of JPX on the downstream janus kinase (JAK)2/signal transducer and activator of transcription (STAT)3 signaling pathway was investigated using Western blot analysis.

Results

When comparing EC tissues to nearby normal tissues, JPX expression is markedly increased in EC tissues, with greater expression in advanced-stage EC. Furthermore, compared to normal epithelial cells, EC cell lines have higher levels of JPX expression. In Ishikawa and JEC endometrial cancer cell lines, we used siRNA-mediated suppression of JPX to find lower cell viability, increased apoptosis, cell cycle arrest, and reduced migration and invasion. We next verified that miR-140-3p binds to downstream target cells to impede the transcription and translation of PIK3CA, which in turn prevents the growth of Ishikawa and JEC cells. JPX functions as a ceRNA to adsorb miR-140-3p. This procedure required controlling JAK2/STAT3, a downstream signal.

Conclusion

JPX enhances the development of Ishikawa and JEC cells and activates downstream JAK2/STAT3 signal transduction via the miR-140-3p/PIK3CA axis, offering a possible therapeutic target for the treatment of EC.

Practical Updates and Diagnostic Challenges in Endometrial Carcinoma

CONTEXT.—

Clinical management of endometrial carcinoma largely depends on the morphologic parameters ascertained based on the pathologic evaluation of surgical resection specimens. However, there are numerous controversial and nonstandardized aspects of both the macroscopic and microscopic assessment of surgical specimens, including grossing, adequate sampling, diagnosis, staging, reporting, and ancillary testing.

OBJECTIVE.—

To provide a comprehensive practical review of standardized grossing, key morphologic findings for reporting and staging, and diagnostic and prognostic use of ancillary testing in endometrial carcinomas.

DATA SOURCES.—

The existing literature, recommendations of the International Society of Gynecological Pathologists, and specialty consensus guidelines.

CONCLUSIONS.—

This review article summarizes important aspects of the grossing and sampling of surgical resection specimens for microscopic examination, key morphologic parameters that are required for reporting and staging, and morphologic features and immunoprofiles helpful in the differential diagnosis of low-grade and high-grade endometrial carcinomas, as well as the current status of the molecular classification of endometrial carcinoma and human epidermal growth factor receptor 2 testing in serous carcinoma. The information presented herein can be helpful in overcoming diagnostic challenges and issues related to the pathology reporting of endometrial carcinoma to practicing anatomic pathologists.

Identifying clinical features and molecular characteristics of the endometrial clear cell carcinoma

Objective

The aim of this study was to verify TCGA subtypes in endometrial clear cell carcinoma (ECCC) and determine their clinical and molecular characteristics.

Methods

We summarized and compared the clinical features of 28 clear cell carcinoma and 112 endometrioid carcinoma patients. Of the 28 ECCCs, 19 underwent TCGA classification, and other markers (ER, PR, ARID1A, ARIB1B, TAF1, and HER-2) were also detected by IHC, and outcomes were assessed.

Results

Compared to endometrioid carcinoma, ECCC had an older age of onset (median age, 64.5 years, range 31-81 years), higher rate of myometrial invasion (42.8% vs. 21.5% in endometrioid carcinoma), LVSI (33% vs. 16%), and more advanced FIGO stage. Among the ECCCs, LVSI was a poor prognostic factor. TCGA classification was performed for 19 ECCCs: two POLEmut cases (10.5%), three MMRd (15.8%), 11 p53wt (57.9%), and three p53abn (15.8%). Of the 19 ECCCs, six (31.6%) showed HER-2 positive expression, and eight (42.1%) had TAF1 expression loss. ECCCs possessed HER-2 and TAF1 expression had worse outcomes.

Conclusion

Our study summarized the clinical features of ECCC. The outcomes of patients with ECCC with TCGA subtypes differed from those of patients with endometrioid carcinoma. HER-2 and TAF1 may be new prognostic factors.

Gastric (gastrointestinal)-type endometrial adenocarcinoma presenting as a solitary endometrial polyp: a case report and literature review on a novel and potentially aggressive endometrial cancer histotype

Gastric-type carcinoma of the endometrium is a rare endometrial cancer histotype, recently introduced in the 2020 WHO classification of the female genital tract tumors. Clinico-pathological features, as well as treatment strategies for this rare histotype, are not fully defined. We herein present an unusual case of endometrial carcinoma with mucinous features arising in a 58-year-old menopausal woman. Morphological features of the present case as well as immunohistochemical profile were consistent with gastrointestinal differentiation. Therefore, after clinical and imaging studies ruled out the possibility of a metastatic origin, a final diagnosis of gastric-type carcinoma of the endometrium was rendered.

p16 Immunohistochemical Expression in Nephrogenic Adenoma

Nephrogenic adenoma (NA) is a rare metaplastic entity commonly associated with a prior urothelial injury. Most are seen in the urinary bladder and a minority involve the urethra. In this study, we evaluated the expression of p16 as a surrogate marker of this entity and correlated it with clinical pathological parameters. A total of 17 cases of NA were retrospectively studied to assess the immunohistochemical expression of p16 and its value for the diagnosis of this entity.

Clinical, pathological, and comprehensive molecular analysis of the uterine clear cell carcinoma: a retrospective national study from TMRG and GINECO network

BACKGROUND

Uterine clear cell carcinomas (CCC) represent less than 5% of uterine cancers. Their biological characteristics and clinical management remain uncertain. A multicenter study to explore both clinical and molecular features of these rare tumors was conducted.

METHODS

This multicenter retrospective national study was performed within the French TMRG (Rare Gynecologic Malignant Tumors) network. Clinical data and, when available, FFPE blocks were collected. Clinical features, treatments, and outcome (progression-free survival (PFS) and overall survival (OS)) were analyzed and correlated to the protein (tissue micro-array), RNA (Nanostring nCounter® technology), and DNA (array-Comparative Genomic hybridization and target-next generation sequencing) levels using the tumor samples available.

RESULTS

Sixty-eight patients with uterine CCC were enrolled, 61 from endometrial localization and 5 with cervix localization. Median age at diagnosis was 68.9 years old (range 19-89.7). Most tumors were diagnosed at an early stage (78% FIGO stage I-II). Hysterectomy (performed in 90%) and lymph node dissection (80%) were the most frequent surgical treatment. More than 70% of patients received external beam radiotherapy and 57% received brachytherapy. Nearly half (46%) of the patients received chemotherapy. After a median follow-up of 24.7 months, median PFS was 64.8 months (95 CI [5.3-124.4]) and median OS was 79.7 (IC95 [31.0-128.4]). Low hormone receptor expression (13% estrogen-receptor positive), frequent PI3K pathway alterations (58% PTEN loss, 50% PIK3CA mutations), and P53 abnormalities (41%) were observed. Mismatch repair deficiency was identified in 20%. P16 expression was associated with shorter PFS (HR = 5.88, 95 CI [1.56-25], p = 0.009). Transcriptomic analyzes revealed a specific transcriptomic profile notably with a high expression of immune response-associated genes in uterine CCC displaying a very good overall prognosis.

CONCLUSIONS

Uterine CCC reported to be potentially MSI high, hormone receptors negative, and sometimes TP53 mutated. However, some patients with immune response-associated features and better prognosis may be candidate to treatment de-escalation and immunotherapy.

Pure and mixed clear cell carcinoma of the endometrium: A molecular and immunohistochemical analysis study

BACKGROUND

Uterine clear cell carcinoma (CCC) consists of either pure clear cell histology but can also display other histological components (mixed uterine CCCs). In this study, the molecular and immunohistochemical background of pure and mixed uterine CCC was compared. Secondly, it was evaluated whether histological classification and molecular background affected clinical outcome.

METHODS

A retrospective multicenter study was performed comparing pure uterine CCCs (n = 22) and mixed uterine CCCs (n = 21). Targeted next-generation sequencing using a 12-gene targeted panel classified cases as polymerase-ε (POLE) mutated, microsatellite instable (MSI), TP53 wildtype or TP53 mutated. Immunohistochemistry was performed for estrogen receptor, progesterone receptor, L1 cell adhesion molecule, MSH6, and PMS2.

RESULTS

The following molecular subgroups were identified for pure and mixed uterine CCCs, respectively: POLE mutated 0% (0/18) and 6% (1/18); MSI in 6% (1/18) and 50% (9/18); TP53 wildtype in 56% (10/18) and 22% (4/18); TP53 mutated in 39% (7/18) and 22% (4/18) (p = 0.013). Patients with mixed CCCs had improved outcome compared to patients with pure CCCs. Frequent TP53 mutations were found in pure CCCs and frequent MSI in mixed CCCs, associated with clinical outcome.

CONCLUSION

Pure and mixed uterine CCCs are two entities with different clinical outcomes, which could be explained by different molecular backgrounds. These results underline the relevance of both morphological and molecular evaluation, and may assist in tailoring treatment.

Molecular Landscape of Mullerian Clear Cell Carcinomas Identifies The Cancer Genome Atlas-like Prognostic Subgroups

Mullerian clear cell carcinoma (CCC) is often aggressive and chemoresistant. The prognostic significance of molecular subclassification of endometrioid carcinomas is well established. However, less is known about the molecular landscape of CCC. The aim of this study was to better characterize the genetic landscape of a large cohort of CCC and correlate these findings with clinicopathologic features. CCC of the ovary (n = 72), endometrium (n = 24), and peritoneum/abdominal wall (n = 5) were retrospectively identified. Tumors had undergone tumor-only targeted sequencing using a hybrid capture next-generation sequencing panel. Median tumor mutational burden was 6.8 mutations/megabase (range, 1.3-185, 21% were ≥10 mutations/Mb). The most frequently mutated genes were ARID1A (48%), PIK3CA (45%), TP53 (23%), and PTEN (10%). ERBB2 amplification occurred in 4%. When classified according to the Cancer Genome Atlas/the Proactive Molecular Risk Classifier for Endometrial Cancer endometrial carcinoma molecular subgroups, 3 (3%) were POLE ultramutated, 5 (5%) were microsatellite instability-high (MSI-H), 20 (20%) were TP53-mutant subgroup, and 73 (72%) were no specific molecular profile (NSMP). Immunohistochemical expression of estrogen receptor, progesterone receptor, and programmed death-ligand 1 were not associated with the molecular subgroup. POLE and MSI-H tumors were characterized by an excellent prognosis, and the TP53-mutant subgroup had a worse disease-free survival than NSMP. NSMP tumors could be further substratified as high-risk NSMP if they lacked PIK3CA, PIK3R1, and ARID1A mutations, and/or harbored a TERT-promoter mutation. The Cancer Genome Atlas and NSMP-specific stratifications were prognostic for both the entire cohort and the subset of stage I ovarian tumors. On multivariable analysis, stage, lymphovascular invasion, and tumor mutational burden were prognostic for disease-free survival, whereas advanced stage and TP53-mutant subgroup - but not a TP53 mutation in isolation - were negative prognostic factors for overall survival. These data suggest that routine molecular profiling of Mullerian CCC may be warranted for both prognosis and identification of potential targeted treatments, such as immunotherapy and anti-HER2 agents.

Type II endometrial cancer: Incidence, overall and disease-free survival in Martinique

BACKGROUND AND STUDY AIMS

In Martinique, about 33 new cases of endometrial cancer are diagnosed per year with a high mortality rate (world standardised rate of 4.9/100,000 versus 2.3/100,000 in mainland France). The present study aimed to determine the incidence and mortality of type I and type II endometrial cancers (ECs), their overall survival (OS) and disease-free survival (DFS) between 2012 and 2016.

PATIENTS AND METHODS

This retrospective observational cohort study used data from the Martinique Cancer Registry (MCR). 191 patients with corpus uterine cancer were extracted between 2012 and 2016. Patients with either endometrioid endometrial carcinoma (EEC), uterine papillary serous carcinomas (UPSC), uterine clear cell carcinomas (UCCC) or uterine carcinosarcomas (UCS) were included. All other uterine cancers were excluded.

RESULTS

Among the 163 included patients, 97 (60%) were type I and 66 (40%) were type II. The standardized incidence rate is 4.50/100,000 for type I vs. 2.66/100,000 for type II. Three years DFS for all types, type I and type II was 81.5% [74.2-86.9], 84.9% [75.4-91] and 76.7% [63.8-85.5] respectively. The five-years OS for all types, type I and type II was 47.0% [38.9-54.7] vs. 58.8% [47.3-68.5] vs. 22.8% [15.0-37.7] respectively.

CONCLUSIONS

In Martinique, we report a high proportion of type II ECs, which has a poor prognosis with few treatment options.

The Role of Immunohistochemistry Markers in Endometrial Cancer with Mismatch Repair Deficiency: A Systematic Review

The objective of this systematic review was to summarize our current knowledge of the role of immunohistochemistry (IHC) markers for identifying mismatch repair-deficient (MMRd) tumors in endometrial cancer (EC). Identification of MMRd tumors, which occur in 13% to 30% of all ECs, has become critical for patients with colorectal and endometrial cancer for therapeutic management, clinical decision making, and prognosis. This review was conducted by two authors applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using the following terms: “immunohistochemistry and microsatellite instability endometrial cancer” or “immunohistochemistry and mismatch repair endometrial cancer” or “immunohistochemistry and mismatch repair deficient endometrial cancer”. Among 596 retrieved studies, 161 fulfilled the inclusion criteria. Articles were classified and presented according to their interest for the diagnosis, prognosis, and theragnostics for patients with MMRd EC. We identified 10, 18, and 96 articles using IHC expression of two, three, or four proteins of the MMR system (MLH1, MSH2, MHS6, and PMS2), respectively. MLH1 promoter methylation was analyzed in 57 articles. Thirty-four articles classified MMRd tumors with IHC markers according to their prognosis in terms of recurrence-free survival (RFS), overall survival (OS), stage, grade, and lymph node invasion. Theragnostics were studied in eight articles underlying the important concentration of PD-L1 in MMRd EC. Even though the role of IHC has been challenged, it represents the most common, robust, and cheapest method for diagnosing MMRd tumors in EC and is a valuable tool for exploring novel biotherapies and treatment modalities.

Diagnostic accuracy of HNF1β, Napsin A and P504S/Alpha-Methylacyl-CoA Racemase (AMACR) as markers of endometrial clear cell carcinoma

Endometrial clear cell carcinoma (CCC) shows morphological overlap with endometrioid and serous carcinoma. We aimed to assess the accuracy of immunohistochemical diagnostic markers of CCC, i.e. HNF1β, Napsin A and P504S/Alpha-Methylacyl-CoA Racemase (AMACR). A systematic review and meta-analysis was conducted by searching 4 electronic databases from their inception to April 2022 for all studies assessing HNF1β, Napsin A and/or AMACR in endometrial CCC vs endometrioid/serous carcinomas. Diagnostic accuracy was assessed as sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-), diagnostic odds ratio (DOR) and area under the curve (AUC) on sROC curves. Eleven studies were included. HNF1β positivity (any expression) showed sensitivity= 0.78; specificity= 0.81; LR+ =2.46; LR-= 0.38; DOR= 5.96; AUC= 0.79. Diffuse HNF1β expression showed sensitivity= 0.53; specificity= 0.95; LR+ =9.68; LR-= 0.51; DOR= 18.02; AUC= 0.40. Napsin A positivity (any expression) showed sensitivity= 0.76; specificity= 0.97; LR+ =18.79; LR-= 0.27; DOR= 73.31; AUC= 0.81. Diffuse Napsin A expression showed sensitivity= 0.52; specificity= 0.99; LR+ =14.50; LR-= 0.55; DOR= 24.93; AUC= 0.98. AMACR positivity (any expression) showed sensitivity= 0.76; specificity= 0.86; LR+ =4.86; LR-= 0.30; DOR= 13.56; AUC was not assessable due to the presence of only 2 studies. In conclusion, HNF1β, Napsin A and AMACR show moderate accuracy in identifying endometrial CCC. Considering only a diffuse expression of these markers as positive leads to high specificity but low sensitivity. In particular, Napsin A appears as the most specific marker of endometrial CCC.

Clear Cell Carcinoma of the Endometrium: Evaluation of Prognostic Parameters in 27 Cases

OBJECTIVE

Clear cell carcinoma (CCC) of the endometrium is an uncommon yet aggressive tumor. Few cohort studies are reporting the overall survival time of CCC patients. This study aimed to retrospectively analyze the clinicopathologic features, molecular characteristics and survival data of 27 endometrial CCC patients to improve the understanding of CCC.

METHODS

The clinicopathologic features, molecular characteristics and survival data total of 27 CCC patients admitted to the BBMU affiliated hospital (Anhui, China) between January 2005 and December 2018 were retrospectively analyzed. Kaplan-Meier method was used to analyze the prognosis-related factors.

RESULTS

The median age of the patients was 60 years (range; 39 to 81 years). The average tumor size was 3.8 cm (range; 0.8 to 13.0cm). Myometrial infiltration greater than 50% was reported in 55.6% of the patients, while the Ki-67 index greater than 50% was reported in 70.4% of the patients. The patients' FIGO (2009) surgical stages were as follows: 18 I, 3 II, 4 III, and 2 IV. Besides, 7 (25.6%) patients had lymphovascular invasion, 3 (11.1%) patients with distant metastasis, including 1 patient with bone metastasis, and 2 with liver metastasis. Adjuvant treatment included 7 with chemotherapy alone, 9 with radiotherapy alone, and 9 with both radiotherapy and chemotherapy. The median overall survival time from the time of CCC diagnosis was 56 months. ER and PR showed negative expression and P16 showed patchy immunostaining. 18 (63%) cases showed Napsin A positive expression. Loss of MSH2, MSH6 and PTEN were seen in 5, 4 and 7 cases respectively. All cases showed HER-2/nue negative expression.

CONCLUSION

CCC is a rare and invasive tumor. Age of diagnosis, FIGO stage, tumor size, myometrial infiltration, lymphovascular invasion, distant metastasis, Ki-67 index and P53 expression are important indicators to evaluate patient's prognosis (P = 0.048, P < 0.001, P = 0.016, P = 0.043, P = 0.001, P < 0.001, P = 0.026, and P = 0.007, respectively). CCC has a worse prognosis than endometrioid carcinoma (P = 0.002), and there is no significant difference when compared with uterine papillary serous carcinoma (P = 0.155).

Immunohistochemistry in gynecologic carcinomas: Practical update with diagnostic and clinical considerations based on the 2020 WHO classification of tumors

This review provides an update on immunohistochemistry applications-diagnostic, prognostic, and predictive-in the pathology evaluation of gynecologic carcinomas. The 5th edition of the WHO Classification of Female Genital Tumors introduced important changes in the diagnostic classification of lower genital tract, endometrial, and ovarian carcinomas, with major influence on the routine pathology practice. Lower genital tract carcinomas and their precursor lesions are now classified based on their human papillomavirus (HPV)-associated and HPV-independent pathogenesis, reflecting the clinically significant prognostic differences and impacting the therapeutic decision-making. Immunohistochemical markers have an increasing role in the pathology evaluation of endometrial carcinomas: in addition to their traditional use in the differential diagnosis and histologic subtyping, they have also been recently advocated for prognostic classification as surrogates for the TCGA (The Cancer Genome Atlas) molecular groups. New entities - mesonephric-like adenocarcinoma and gastric (gastrointestinal)-type mucinous adenocarcinoma of the endometrium - have also been added and often require immunostains for diagnostic confirmation. Ovarian carcinomas frequently show overlapping morphologic patterns and heterogeneous appearance within the same tumor, necessitating immunohistochemical work-up. Beyond diagnostic applications, there is increasing clinical demand for screening of inherited cancer syndromes, prediction of prognosis and guiding targeted therapy. Practical issues and pitfalls related to mismatch repair protein immunohistochemistry, HER2, and PD-L1 testing are also discussed.

Clear cell endometrial carcinoma precursors: presentation of two cases and diagnostic issues

BACKGROUND

The precursors of clear cell endometrial carcinoma (CC-EC) are still undefined. Here, we deal with the diagnostic issues related to CC-EC precursors by presenting a morphological, immunophenotypical and molecular study of two representative cases and discussing the relevant literature.

CASE PRESENTATION

Our and previous cases suggest that clear cell endometrial intraepithelial carcinoma (CC-EIC) is a real entity, which may be distinguished from metaplastic/reactive changes and from its serous counterpart. CC-EIC appears associated with atrophic polyps and may be diagnosed based on morphological and immunophenotypical features of CC-EC in the absence of invasive disease. We described a p53-mutant putative precursor characterized by high-grade nuclei in the absence of other distinctive features. Two putative low-grade precursors resembled atypical tubal metaplasia and endometrial intraepithelial neoplasia, although immunohistochemistry could not support their relationship with CC-EC.

CONCLUSIONS

In conclusion, pathologists should be aware of the existence of CC-EIC, since its correct diagnosis may be crucial for a correct patient management. Although several putative earlier precursors have been described, they does not show univocal features that allow their recognition in the common practice. Further studies are necessary in this field.

Clear cell endometrial carcinomas with mismatch repair deficiency have a favorable prognosis: A systematic review and meta-analysis

INTRODUCTION

In the ESGO/ESTRO/ESP guidelines for endometrial carcinoma management, the risk category of clear cell carcinoma (CCC) is not well defined. In fact, while p53-abnormal (p53abn) CCC are known to be aggressive, the prognosis of mismatch repair-deficient (MMRd) and p53-wild-type (p53wt) CCCs is less clear.

OBJECTIVE

To assess the prognostic value of the MMRd and p53wt groups in CCC through a systematic review and meta-analysis.

METHODS

Electronic databases were searched from their inception to February 2021. All studies reporting p53 expression, MMR proteins expression and survival outcomes in endometrial CCC (either pure or mixed) were included. Kaplan-Meier and Cox regression survival analyses with hazard ratio (HR) for overall survival (OS) were performed by using the p53abn group as reference; a significant p-value<0.05 was adopted.

RESULTS

Six studies with 136 CCC (114 pure and 22 mixed) were included. Five-year OS was 95.7 ± 4.3% in the MMRd group, 48.4 ± 8.4% months in the p53wt group and 40.6 ± 10.4% in the p53abn group. The hazard of death was significantly lower in the MMRd group than in the p53abn group (HR = 0.062; p = 0.007), while it did not significantly differ between the p53wt and the p53abn group (HR = 0.673; p = 0.222). The POLEmut group could not be analyzed due to the absence of deaths. Similar results were observed in the pure CCC and mixed CCC subgroups.

CONCLUSION

MMRd CCCs seem to have a favorable prognosis and might be lumped together with MMRd endometrioid carcinoma for management purpose. On the other hand, p53wt CCCs appear prognostically more similar to p53abn CCCs.

New Pathological and Clinical Insights in Endometrial Cancer in View of the Updated ESGO/ESTRO/ESP Guidelines

Endometrial carcinoma represents the most common gynecological cancer in Europe and the USA. Histopathological classification based on tumor morphology and tumor grade has played a crucial role in the management of endometrial carcinoma, allowing a prognostic stratification into distinct risk categories, and guiding surgical and adjuvant therapy. In 2013, The Cancer Genome Atlas (TCGA) Research Network reported a large scale molecular analysis of 373 endometrial carcinomas which demonstrated four categories with distinct clinical, pathologic, and molecular features: POLE/ultramutated (7% of cases) microsatellite instability (MSI)/hypermutated (28%), copy-number low/endometrioid (39%), and copy-number high/serous-like (26%). In the present article, we report a detailed histological and molecular review of all endometrial carcinoma histotypes in light of the current ESGO/ESTRO/ESP guidelines. In particular, we focus on the distribution and prognostic value of the TCGA groups in each histotype.

Napsin A Expression in Human Tumors and Normal Tissues

Background: Novel aspartic proteinase of the pepsin family A (Napsin A, TAO1/TAO2) is a functional aspartic proteinase which is involved in the maturation of prosurfactant protein B in type II pneumocytes and the lysosomal protein catabolism in renal cells. Napsin A is highly expressed in adenocarcinomas of the lung and is thus commonly used to affirm this diagnosis. However, studies have shown that other tumors can also express Napsin A.

Methods: To comprehensively determine Napsin A expression in normal and tumor tissue, 11,957 samples from 115 different tumor types and subtypes as well as 500 samples of 76 different normal tissue types were evaluable by immunohistochemistry on tissue microarrays.

Results: Napsin A expression was present in 16 different tumor types. Adenocarcinoma of the lung (85.6%), clear cell adenocarcinoma of the ovary (71.7%), clear cell adenocarcinoma of the endometrium (42.8%), papillary renal cell carcinoma (40.2%), clear cell (tubulo) papillary renal cell carcinoma (16.7%), endometrial serous carcinoma (9.3%), papillary thyroid carcinoma (9.3%) and clear cell renal cell carcinoma (8.2%) were among the tumors with the highest prevalence of Napsin A positivity. In papillary and clear cell renal cell carcinoma, reduced Napsin A expression was linked to adverse clinic-pathological features (p ≤ 0.03).

Conclusion: This methodical approach enabled us to identify a ranking order of tumors according to their relative prevalence of Napsin A expression. The data also show that loss of Napsin A is linked to tumor dedifferentiation in renal cell carcinomas.

An Emerging Anti-p16 Antibody-BC42 Clone as an Alternative to the Current E6H4 for Use in the Female Genital Tract Pathological Diagnosis: Our Experience and a Review on p16ink4a Functional Significance, Role in Daily-Practice Diagnosis, Prognostic Potential, and Technical Pitfalls

Background: To date, useful diagnostic applications of p16 IHC have been documented in gynecological pathology both for HPV-related and non-HPV-related lesions. In the present article, we reported our experience with the novel anti-p16 INK4a antibody (clone BC42), whose expression was tested across all different gynecologic neoplasms; we also compared it to the traditional E6H4 clone. Moreover, we discussed and explored all the diagnostic applications of p16 IHC in gynecologic pathology. Methods: Consultation cases covering a 5-year period (2016–2020) regarding gynecological neoplastic and non-neoplastic lesions in which immunohistochemistry for p16, clone E6H4 was originally performed, were retrospectively retrieved from the files of our institution. Immunohistochemical staining for p16ink4a (BC42) [Biocare Medical group-Paceco USA; Bioptica Milan] and p16ink4a (E6H4) [Ventana Medical Systems-Arizona USA; Roche] was performed by using the Ventana automated immunostainer (Ventana Medical Systems, Tucson, AZ, USA). The immunostaining pattern was defined as negative, focal/patchy, or diffuse. Results: A total of 196 cases, represented by 36 high-grade SIL/CIN3 of the uterine cervix, 30 cervical adenocarcinomas, 22 cervical squamous cell carcinoma, 70 endometrial carcinomas, 25 high grade serous ovarian carcinomas, 6 uterine adenomatoid tumors, and 10 uterine leiomyosarcomas were included in this study. Results showed concordant staining quality of both clones on all tested neoplastic tissues. Conclusions: The novel anti-p16 antibody (BC42 clone) appeared as an alternative to the current E6H4 for use in gynecological neoplasms, offering similar levels of positivity and equally reliable staining results.

Clinico-pathological significance of TCGA classification and SWI/SNF proteins expression in undifferentiated/dedifferentiated endometrial carcinoma: A possible prognostic risk stratification

BACKGROUND

Undifferentiated/dedifferentiated endometrial carcinoma (UEC/DDEC) is a heterogeneous entity, which may show any of the TCGA molecular signatures and loss of the switch/sucrose nonfermentable (SWI/SNF) proteins expression.

AIM

To assess the clinico-pathological significance of the TCGA molecular groups and SWI/SNF proteins expression in UEC/DDEC, through a quantitative systematic review.

METHODS

Electronic databases were searched for all studies assessing the TCGA molecular groups, i.e. POLE-mutant, mismatch repair-deficient (MMRd), p53-abnormal (p53abn) and no specific molecular profile (NSMP), and/or the SWI/SNF proteins (SMARCA4/BRG1, SMARCB1/INI1, ARID1B) expression in UEC/DDEC. Student t-test, Fisher's exact test and Kaplan-Meier survival analysis with long-rank test were used to assess differences among groups; a p-value<0.05 was considered significant.

RESULTS

Eight studies were included in the systematic review. Among the TCGA groups, the mean patient age was significantly higher in the p53abn group than in the NSMP group (p = 0.048). The POLE-mutant group showed advanced FIGO stage (III-IV) significantly less commonly than the NSMP (p = 0.003) and MMRd (p = 0.008) groups, and a significantly better prognosis than the NSMP (p = 0.007), MMRd (p = 0.011) and p53abn (p = 0.045) groups.The SWI/SNF-deficient cases showed a significantly worse prognosis than the SWI/SNF-intact cases (p = 0.010), while no significant differences were found regarding patient age and FIGO stage.

CONCLUSIONS

Among UEC/DDEC, POLE-mutant cases show good prognosis, while SWI/SNF-deficient cases show poor prognosis. The other TCGA molecular subtypes seem to be characterized by an intermediate biological behaviour. On this account, UEC/DDEC patients might be subdivided into three risk groups based on POLE and SWI/SNF status. Further studies are necessary in this field.

DNA mismatch repair deficiency and p53 abnormality are age-related events in mixed endometrial carcinoma with a clear cell component

Mixed endometrial carcinoma (MEC) is defined as a tumor composed of two or more spatially distinct subtypes, at least one of which is serous or clear cell carcinoma. In this study, the clinicopathological features of 15 MEC cases containing a clear cell component (MEC-C) were investigated. The ages of patients ranged from 32 to 83 years (median, 61 years). The combinations of carcinoma components observed were endometrioid and clear cell in ten patients; endometrioid, clear cell and serous in three; and clear cell and serous in two. Immunohistochemically, nine had DNA mismatch repair (MMR) protein deficiency (MMR-d), nine had loss of ARID1A and three cases had aberrant p53 expression. MMR-d and loss of ARID1A showed a strong correlation. Only one case showed both MMR-d and aberrant p53 expression. The patients with MMR-d were younger than those without MMR-d (median; 58 years vs. 71 years). Loss of ARID1A also showed significant predilection for younger women than ARID1A intact cases. In conclusion, MMR-d was observed in 60 % of MEC-C, showed predilection for young women, and was associated with ARID1A loss. In contrast, non- MMR-d MEC-C occurred in elder women and some tumors may associate with TP53 mutation. These findings suggest that MEC-C develop via two different molecular mechanisms and they are age-related events.

Mismatch repair deficiency is associated with specific morphologic features and frequent loss of ARID1A expression in ovarian clear cell carcinoma

BACKGROUND

Ovarian clear cell carcinoma (OCCC) is the second subtype of ovarian epithelial carcinoma reported to be closely related to Lynch syndrome (LS). ARID1A mutation is an important pathogenetic mechanism in OCCC that leads to loss of ARID1A expression in approximately half of OCCCs. However, the correlation of MMR status and ARID1A deficiency is unclear. The current study aimed to identify the clinical and histopathological characteristics of OCCC associated with dMMR and to further explore the association between dMMR and ARID1A deficiency.

METHODS

A cohort of 176 primary OCCC patients was enrolled and review included histological characteristics (nuclear atypia, necrosis, mitosis, stromal hyalinization, and background precursors) and host inflammatory response (tumor-infiltrating lymphocytes, peritumoral lymphocytes, intratumoral stromal inflammation and plasma cell infiltration). Immunohistochemical staining of MLH1, PMS2, MSH2, MSH6 and ARID1A was performed using tissue microarrays.

RESULTS

dMMR was detected in 10/176 tumors (6 %), followed by MSH2/MSH6 (6/176), MLH1/PMS2 (3/176), and MSH6 (1/176). The average age of patients with dMMR was younger than that of patients with intact MMR (46 y vs. 53 y). Tumors with diffuse intratumoral stromal inflammation remained significantly associated after multivariate analysis. ARID1A expression was absent in 8 patients with dMMR (8/10), which is a significantly higher frequency than that observed in patients with intact MMR (80 % vs. 43.2 %).

CONCLUSIONS

Our study indicates that diffuse intratumoral stromal inflammation of OCCCs is associated with dMMR, with loss of MSH2/MSH6 expression being most frequent. dMMR is strongly associated with the loss of ARID1A expression in OCCC.

Diagnostic and Prognostic Role of WT1 Immunohistochemical Expression in Uterine Carcinoma: A Systematic Review and Meta-Analysis across All Endometrial Carcinoma Histotypes

Background: The diagnostic role of Wilms’ tumor 1 (WT1) is well known in gynaeco-pathological setting, since it is considered a specific marker of serous histotype and adnexal origin. Moreover, its oncogenic role has been recently highlighted in many cancers and it has also been regarded as a promising target antigen for cancer immunotherapy. However, the relationship between its expression and prognostic role in uterine cancer remains unclear. We analyzed the diagnostic and prognostic role of WT1 expression in patients with uterine carcinoma by completing a search using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and the PICOS (Participants, Intervention, Comparison, Outcomes, Study Design) model through PubMed, Scopus and Web of Science databases to identify studies that fit our search criteria. The objective of the current meta-analysis was to investigate the diagnostic and prognostic role of WT1 expression in patients with uterine carcinoma. Materials and Methods: A literature search was performed of the PubMed, Scopus, and Web of Science databases for English-language studies published from January 2000 to April 2020. Studies were considered eligible if they evaluated the WT1 expression in uterine carcinoma. Results: In total, 35 articles were identified that used uterine carcinoma criteria and provided data for 1616 patients. The overall rate of WT1 expression in uterine carcinoma was 25%. The subgroup analysis of uterine cancer types revealed that WT1 was expressed differently among different histotypes (endometrioid, clear cell, serous carcinoma and carcinosarcoma). Discussion and Conclusions: The WT1 immunohistochemical expression is not limited to serous histotype and/or ovarian origin. In fact, a significant proportion of endometrial adenocarcinomas can also show WT1 immunoreactivity. Moreover, our study suggests that WT1 may be a potential marker to predict the prognosis of patients with uterine cancer, but more studies are needed to confirm its role in clinical practice.

Pathological features, immunoprofile and mismatch repair protein expression status in uterine endometrioid carcinoma: focus on MELF pattern of myoinvasion

AIMS

Microcystic, elongated, and fragmented (MELF) pattern of myoinvasion has been related with increased risk of lympho-vascular space invasion (LVSI) and lymph node metastasis. We analysed a cohort of endometrioid endometrial carcinomas (EECs) to examine the relationships between the MELF pattern of invasion and the clinico-pathological and immunohistochemical features of EEC.

METHODS AND RESULTS

129 EECs were evaluated for the presence of MELF pattern and immunohistochemically tested for Mismatch repair (MMR) proteins, p16, p53 and beta-catenin. We observed 28 MELF + EECs and 101 MELF- EECs. LVSI was observed in 20 MELF + cases and in MELF- tumors. Lymph-node metastases were observed in 7 MELF + cases (2 macrometastases, 3 micrometastases and 2 ITCs). None of the MELF- cases showed micrometastases or ITCs, 18 cases had macrometastatic lymph-nodes. Statistical analysis showed that MELF + tumors carry an increased risk of developing nodal metastasis independent of tumor dimension and LVSI. Loss of MMR proteins expression was observed in 11 MELF + cases and 45 MELF- cases, respectively. Our data showed a higher frequency of immunohistochemical MLH1-PMS2 loss in MELF- pattern of invasion (32.67% of MELF- cases vs 21.43% of MELF + cases) but a higher prevalence of MSH2-MSH6 loss in MELF + pattern (7.14% in MELF + population vs 3.96% of MELF- population) CONCLUSIONS: The morphological recognition of MELF pattern is more reliable than immunohistochemical and molecular signatures of EEC in predicting the risk of nodal involvement. The observed higher prevalence of MSH2-MSH6 loss in MELF + group and MLH1-PMS2 loss in MELF- group may suggest a different molecular signature.

Molecular subtypes of clear cell carcinoma of the endometrium: Opportunities for prognostic and predictive stratification

OBJECTIVE

Our aim was to characterize the pathological, molecular and clinical outcomes of clear cell carcinoma of the endometrium (CCC).

METHODS

CCC underwent ProMisE (Proactive Molecular Risk Classifier for Endometrial Cancer) classification identifying four molecular subtypes: i) 'POLEmut' for ECs with pathogenic POLE mutations, ii) 'MMRd', if there is loss of mismatch repair proteins by immunohistochemistry (IHC), iii) 'p53wt' or iv) 'p53abn' based on p53 IHC staining. Clinicopathologic parameters, immune markers (CD3, CD8, CD79a, CD138, PD-1), ER, L1CAM, and outcomes were assessed.

RESULTS

52 CCCs were classified, including 1 (2%) POLEmut, 5 (10%) MMRd, 28 (54%) p53wt and 18 (35%) p53abn. Women with p53abn and p53wt CCCs were older than women with MMRd and POLEmut subtypes. p53wt CCC were distinct from typical p53wt endometrioid carcinomas; more likely to arise in older, thinner women, with advanced stage disease, LVSI and lymph node involvement, and a higher proportion ER negative, L1CAM overexpressing tumors with markedly worse outcomes. High levels of immune infiltrates (TIL^high) were observed in 75% of the CCC cohort. L1CAM overexpression was highest within p53abn and p53wt subtypes of CCC.

CONCLUSION

CCC is a heterogeneous disease encompassing all four molecular subtypes and a wide range of clinical outcomes. Outcomes of patients with POLEmut, MMRd and p53abn CCC are not distinguishable from those of other patients with these respective subtypes of EC; p53wt CCC, however, differ from endometrioid p53wt EC in clinical, pathological, molecular features and outcomes. Thus, p53wt CCC of endometrium appear to be a distinct clinicopathological entity within the larger group of p53wt ECs.