Dedifferentiated Carcinomas Research Articles

Endometrial Carcinosarcomas are Almost Exclusively of p53abn Molecular Subtype After Exclusion of Mimics.

Our aim was to assess the molecular subtype(s) and perform a detailed morphologic review of tumors diagnosed as carcinosarcoma in a population-based cohort. Forty-one carcinosarcomas were identified from a cohort of 973 endometrial carcinomas diagnosed in 2016. We assessed immunostaining and sequencing data and undertook expert pathology reviews of these cases as well as all subsequently diagnosed (post-2016) carcinosarcomas of no specific molecular profile (NSMP) molecular subtype (n=3) from our institutions. In the 2016 cohort, 37 of the 41 carcinosarcomas (91.2%) were p53abn, 2 (4.9%) were NSMP, and 1 each (2.4%) were POLE mut and mismatch repair deficiency molecular subtypes, respectively. Of the 4 non-p53abn tumors on review, both NSMP tumors were corded and hyalinized (CHEC) pattern endometrioid carcinoma, the mismatch repair deficiency tumor was a grade 1 endometrioid carcinoma with reactive stromal proliferation, and the POLE mut tumor was grade 3 endometrioid carcinoma with spindle cell growth, that is, none were confirmed to be carcinosarcoma on review. We found 11 additional cases among the 37 p53abn tumors that were not confirmed to be carcinosarcoma on the review (3 undifferentiated or dedifferentiated carcinomas, 5 carcinomas with CHEC features, 2 carcinomas showing prominent reactive spindle cell stroma, and 1 adenosarcoma). In the review of institutional cases reported as NSMP carcinosarcoma after 2016, 3 were identified (1 adenosarcoma and 2 mesonephric-like adenocarcinoma on review). In this series, all confirmed endometrial carcinosarcomas were p53abn. The finding of any other molecular subtype in a carcinosarcoma warrants pathology review to exclude mimics.

MicroRNA Landscape in Endometrial Carcinomas in an Asian population: Unraveling Subtype-Specific Signatures.

MicroRNAs (MiRNAs) are small, non-coding RNA molecules that function in RNA silencing and post-transcriptional regulation of gene expression. We analyzed the differential expression of miRNAs in 119 endometrial carcinomas, measuring their expression in histological subtypes, molecular subtypes, and tumors with CTNNB1 mutations. Tumors were subdivided into histological and molecular subtypes as defined by The Cancer Genome Atlas. The expression levels of 352 miRNAs were quantified using the PanoramiR panel. Mir-449a, mir-449b-5p, and mir-449c-5p were the top three miRNAs showing increased expression in both endometrioid and de-differentiated carcinomas but were not significantly increased in serous and clear cell carcinomas. The miRNAs with the most increased expression in serous and clear cell carcinomas were miR-9-3p and miR-375, respectively. We also identified 62 differentially expressed miRNAs among different molecular subtypes. Using sequential forward selection, we built subtype classification models for some molecular subtypes of endometrial carcinoma, comprising 5 miRNAs for MMR-deficient tumors, 10 miRNAs for p53-mutated tumors, and 3 miRNAs for CTNNB1-mutated tumors, with areas under curves of 0.75, 0.85, and 0.78, respectively. Our findings confirm the differential expression of miRNAs between various endometrial carcinoma subtypes and may have implications for the development of diagnostic and prognostic tools.

Clinicopathological and molecular characterization of high-grade endometrial carcinoma with POLE mutation: a single center study.

ObjectiveThe molecular classification system of endometrial carcinoma (EC) in ‘The Cancer Genome Atlas’ is widely acknowledged for its prognostic utility. Subsequently, more simplified classification system that incorporate DNA polymerase epsilon (POLE) exonuclease domain mutations, mismatch repair deficiencies (MMRd), and abnormal p53 (P53abn) has also demonstrated its clinical utility. These classifications helped identifying a ‘POLE ultramutated’ (POLEmut) category of patients, most of whom show excellent prognoses despite having high-grade ECs. We aimed to investigate the clinicopathological and molecular characteristics of high-grade ECs with POLEmut.MethodsWe investigated 414 patients with high-grade ECs (including endometrioid carcinomas grade 3, serous carcinomas, clear cell carcinomas, mixed carcinomas, undifferentiated and dedifferentiated carcinomas, and carcinosarcomas) by sequencing and immunohistochemical staining.ResultsForty-three tumors (10.4%) were classified as POLEmut, including 2 with new, possibly pathogenic POLE mutations at P286C and L424V. These patients had very good prognoses except for 1 with stage IV disease and residual tumor. Eleven patients in this group also had P53abn and 4 had MMRd; molecular analysis revealed that patients with synchronous POLE pathogenic mutation and other mutations had a POLEmut or MMRd phenotype; survival analysis found no difference in prognosis between these patient categories. The prognoses of patients in the POLEmut EC group were not significantly influenced by treatment or risk category.ConclusionsPatients with high-grade EC exhibiting POLEmut have very good clinical outcomes, and should be identified urgently in daily work owing to their conflicting morphology. Our findings also provide guidance on subclassifying ECs with poor histological appearance.

Undifferentiated and dedifferentiated urological carcinomas: lessons learned from the recent developments

Loss of the morphological and immunophenotypic characteristics of a neoplasm is a well-known phenomenon in surgical pathology and occurs across different tumor types in almost all organs. This process may be either partial, characterized by transition from well differentiated to undifferentiated tumor component (=dedifferentiated carcinomas) or complete (=undifferentiated carcinomas). Diagnosis of undifferentiated carcinoma is significantly influenced by the extent of sampling. Although the concept of undifferentiated and dedifferentiated carcinoma has been well established for other organs (e.g. endometrium), it still has not been fully defined for urological carcinomas. Accordingly, undifferentiated/ dedifferentiated genitourinary carcinomas are typically lumped into the spectrum of poorly differentiated, sarcomatoid, or unclassified (NOS) carcinomas. In the kidney, dedifferentiation occurs across all subtypes of renal cell carcinoma (RCC), but certain genetically defined RCC types (SDH-, FH- and PBRM1- deficient RCC) seem to have inherent tendency to dedifferentiate. Histologically, the undifferentiated component displays variable combination of four patterns: spindle cells, pleomorphic giant cells, rhabdoid cells, and undifferentiated monomorphic cells with/without prominent osteoclastic giant cells. Any of these may occasionally be associated with heterologous mesenchymal component/s. Their immunophenotype is often simple with expression of vimentin and variably pankeratin or EMA. Precise subtyping of undifferentiated (urothelial versus RCC and the exact underlying RCC subtype) is best done by thorough sampling supplemented as necessary by immunohistochemistry (e.g. FH, SDHB, ALK) and/ or molecular studies. This review discusses the morphological and molecular genetic spectrum and the recent develoments on the topic of dedifferentiated and undifferentiated genitourinary carcinomas.

Cytologic features of undifferentiated and dedifferentiated carcinomas of the endometrium.

Undifferentiated carcinoma (UC) is a rare, aggressive subtype of endometrial carcinoma. Dedifferentiated carcinomas (DCs) are UCs associated with a component of well differentiated endometrioid carcinoma. The authors sought to describe the morphologic features of UCs and DCs in cytologic specimens. Cytologic specimens from 23 women (aged 46-86years; median age, 59years) were reviewed, including cervicovaginal specimens (n=7), peritoneal washings (n=5), touch preparations of core biopsies from various sites (n=5), fine-needle biopsies of lymph nodes (n=3), ascitic fluid (n=1), pleural fluid (n=1), and intrauterine fluid (n=1). There were 10 UCs (43%) and 13 DCs (57%). Tumor cells were arranged as single cells (9 UCs, 90%; 12 DCs, 92%) and 3-dimensional groups (8 UCs, 80%; 11 DCs, 85%). Most cases showed high nuclear-to-cytoplasmic ratios. Nuclear molding was observed in 3 UCs (30%) and in 5 DCs (38%). Nuclear chromatin was often coarsely granular 6 UCs, 60%; 9 DCs, 69%). Nucleoli were inconspicuous in some cases (6 UCs, 60%; 8 DCs, 62%) but were appreciable in others. Necrosis was observed in 5 UCs (50%) and in 5 DCs (38%). Most cases exhibited clean backgrounds, and a few showed acute inflammation. Comparison of the cytologic features of UCs and DCs did not reveal any statistically significant differences. UCs and DCs have a spectrum of cytomorphologic appearances that are not pathognomonic, but the presence of some of these (relatively uniform population of predominantly singly dispersed cells with high nuclear-to-cytoplasmic ratios and variably conspicuous nucleoli) should prompt consideration of UC and DC in the differential diagnosis.

Role of epithelial-mesenchymal transition factors in the histogenesis of uterine carcinomas.

Several subtypes of high-grade endometrial carcinomas (ECs) contain an undifferentiated component of non-epithelial morphology, including undifferentiated and dedifferentiated carcinomas and carcinosarcomas (CSs). The mechanism by which an EC undergoes dedifferentiation has been the subject of much debate. The epithelial-mesenchymal transition (EMT) is one of the mechanisms implicated in the transdifferentiation of high-grade carcinomas. To improve our understanding of the role of EMT in these tumors, we studied a series of 89 carcinomas including 14 undifferentiated/dedifferentiated endometrial carcinomas (UECs/DECs), 49 CSs (21 endometrial, 29 tubo-ovarian and peritoneal), 17 endometrioid carcinomas (grade 1-3), and 9 high-grade serous carcinomas of the uterus, using a panel of antibodies targeting known epithelial markers (Pan-Keratin AE1/AE3 and E-cadherin), mesenchymal markers (N-cadherin), EMT transcription factors (TFs) (ZEB1, ZEB2, TWIST1), PAX8, estrogen receptors (ER), progesterone receptors (PR), and the p53 protein. At least one of the three EMT markers (more frequently ZEB1) was positive in the sarcomatous component of 98% (n = 48/49) of CSs and 98% (n = 13/14) of the undifferentiated component of UEC/DEC. In addition, 86% of sarcomatous areas of CSs and 79% of the undifferentiated component of UEC/DEC expressed all three EMT-TFs. The expression of these markers was associated with the loss of or reduction in epithelial markers (Pan-keratin, E-cadherin), PAX8, and hormone receptors. In contrast, none of the endometrioid and serous endometrial carcinomas expressed ZEB1, while 6% and 36% of endometrioid and 11% and 25% of serous carcinomas focally expressed ZEB2 and TWIST1, respectively. Although morphologically different, EMT appears to be implicated in the dedifferentiation in both CSs and UEC/DEC. Indeed, we speculate that the occurrence of EMT in a well differentiated endometrioid carcinoma may consecutively lead to a dedifferentiated and undifferentiated carcinoma, while in a type II carcinoma, it may result in a CS.

Concurrent ARID1A and ARID1B inactivation in endometrial and ovarian dedifferentiated carcinomas

Dedifferentiated carcinoma of the endometrium or the ovary is an aggressive epithelial malignancy that comprises an endometrioid carcinoma together with an undifferentiated carcinoma. We recently reported that inactivation of BRG1 or INI1, core subunits of the switch/sucrose non-fermenting (SWI/SNF) complex, was the likely molecular event underlying dedifferentiation in about half of dedifferentiated carcinomas. In this study, we performed a genomic screen that included other members of the SWI/SNF complex to better delineate the molecular basis in the remainder of these tumours. We identified concurrent inactivating mutations involving ARID1A and ARID1B in 12 of 24 BRG1/INI1-intact, 0 of 3 INI1-deficient and 0 of 16 BRG1-deficient dedifferentiated carcinomas. All ARID1A and ARID1B co-mutated tumours displayed loss of ARID1A expression in the undifferentiated component with 11 of 12 tumours also displaying absent staining in the endometrioid component. ARID1B expression was absent in the undifferentiated component in all 12 tumours, whereas the corresponding endometrioid component showed intact expression. Clinically, ARID1A/ARID1B co-inactivated tumours showed similar aggressive behaviour to BRG1 or INI1-inactivated tumours. Given that ARID1A and ARID1B are the only known DNA-binding subunits of the SWI/SNF-A complex, additional inactivation of ARID1B in an ARID1A-deficient background appears to represent an alternative mechanism of disruption of SWI/SNF-mediated transcriptional regulation, resulting in arrested cellular differentiation in endometrial and ovarian endometrioid cancer.

Loss of switch/sucrose non-fermenting complex protein expression is associated with dedifferentiation in endometrial carcinomas

Dedifferentiated endometrial carcinoma is an aggressive type of endometrial cancer that contains a mix of low-grade endometrioid and undifferentiated carcinoma components. We performed targeted sequencing of eight dedifferentiated carcinomas and identified somatic frameshift/nonsense mutations in SMARCA4, a core ATPase of the switch/sucrose non-fermenting (SWI/SNF) complex, in the undifferentiated components of four tumors. Immunohistochemical analysis confirmed the loss of SMARCA4 in the undifferentiated component of these four SMARCA4-mutated cases, whereas the corresponding low-grade endometrioid component showed retained SMARCA4 expression. An expanded survey of other members of the SWI/SNF complex showed SMARCB1 loss in the undifferentiated component of two SMARCA4-intact tumors, and all SMARCA4- or SMARCB1-deficient tumors showed concomitant loss of expression of SMARCA2. We subsequently examined the expression of SMARCA2, SMARCA4, and SMARCB1 in an additional set of 22 centrally reviewed dedifferentiated carcinomas and 31 grade 3 endometrioid carcinomas. Combining the results from the index and the expansion set, 15 of 30 (50%) of the dedifferentiated carcinomas examined showed either concurrent SMARCA4 and SMARCA2 loss (37%) or concurrent SMARCB1 and SMARCA2 loss (13%) in the undifferentiated component. The loss of SMARCA4 or SMARCB1 was mutually exclusive. All 31 grade 3 endometrioid carcinomas showed intact expression of these core SWI/SNF proteins. The majority (73%) of the SMARCA4/SMARCA2-deficient and half of SMARCB1/SMARCA2-deficient undifferentiated component developed in a mismatch repair-deficient molecular context. The observed spatial association between SWI/SNF protein loss and histologic dedifferentiation suggests that inactivation of these core SWI/SNF proteins may contribute to the development of dedifferentiated endometrial carcinoma.

SWI/SNF complex deficiency and mismatch repair protein expression in undifferentiated and dedifferentiated endometrial carcinoma

Undifferentiated endometrial carcinoma (UEC) is a relatively uncommon but clinically aggressive uterine malignancy. In common with a subset of poorly differentiated carcinomas arising in other sites, UEC may exhibit rhabdoid morphology and be associated with a low-grade tumour component (dedifferentiated carcinoma). Recent studies have implicated inactivation of the SWI/SNF complex subunits in the aforementioned extrauterine tumours. Therefore we have examined INI1 (SMARCB1), BRG1 (SMARCA4), and BAF250a (ARID1A) immunostaining, and also expression of the DNA mismatch repair (MMR) proteins MLH1, PMS2, MSH2 and MSH6 in 22 UEC, seventeen of which were dedifferentiated. Abnormal SWI/SNF subunit expression was detected in four dedifferentiated carcinomas including three with loss of BRG1 staining limited to the undifferentiated tumour component and one case with loss of INI1 expression in both low- and high-grade elements; the latter case also showed BAF250a deficiency in the undifferentiated tumour cells. Abnormal MMR protein expression was identified in 13 tumours (59%) including nine with concurrent loss of MLH1 and PMS2. These findings suggest that SWI/SNF subunit alterations may play a role in the progression/ dedifferentiation of endometrial carcinoma, and that SWI/SNF and MMR protein deficiencies may act synergistically in deregulating DNA repair mechanisms in these tumours.

Fascin expression in undifferentiated and dedifferentiated endometrial carcinoma.

The actin-binding protein fascin promotes cellular invasion, and increased fascin expression correlates with adverse prognostic factors in a variety of tumors. Fascin up-regulation may also be associated with epithelial-mesenchymal transition in neoplastic epithelial cells. This study investigated fascin expression in undifferentiated and dedifferentiated endometrial carcinoma (UEC), a clinically aggressive variant of endometrial neoplasia. Twenty-two UECs, 5 of which were entirely undifferentiated and 17 dedifferentiated, were examined. In the dedifferentiated group, staining was compared between the differentiated and undifferentiated tumor components. Where applicable, fascin expression was noted in foci of lymphovascular space invasion. The mean age was 67.6 years, and 11 patients (50%) presented with stage III or IV disease. The undifferentiated tumor component showed diffuse fascin expression in 20 cases (91%) including 4 of 5 pure undifferentiated carcinomas and 16 of 17 dedifferentiated carcinomas. In contrast, the low-grade endometrioid carcinoma component of 13 (77%) of 17 dedifferentiated carcinomas was fascin negative or showed only focal staining. Intravascular undifferentiated tumor cells were identified in 16 cases, and these were consistently fascin positive, whereas low-grade intravascular tumor cells, present in 2 cases, were not stained. Fascin up-regulation may be a contributory factor toward the highly invasive character of UEC and could represent an epithelial-mesenchymal transition-like process in these tumors. Fascin expression in intravascular tumor cells may be permissive toward intravascular survival and metastatic risk.

MicroRNAs Regulate Endometrial and Ovarian Cancer Sensitivity to Anoikis and Chemotherapy.

Background and objective: MicroRNA-200c directly targets and represses ZEB1 and ZEB2. These transcription factors cause epithelial to mesenchymal transition (EMT) by repressing E-cadherin and other key determinates of apical-basal polarity. We find that miR-200c is high in well-differentiated breast, endometrial and ovarian cancer cells and low grade tumors, but is extremely low in de-differentiated carcinomas that have undergone EMT. We postulated that miR-200c maintains the well-differentiated epithelial phenotype by directly inhibiting translation of additional targets that play a role in multiple steps in the metastatic cascade including loss of polarity, migration/invasion, resistance to anoikis and drug resistance. Using luciferase 3'UTR reporter assays with mutational analysis, we have identified many direct targets of miR-200c. These targets, including fibronectin 1 (FN1), moesin (MSN), class III beta-tubulin (TUBB3), and neurotrophic tyrosine receptor kinase type 2 (NTRK2 or TrkB), are all typically expressed in non-epithelial cells, such as fibroblasts or neurons, but can become expressed in highly de-differentiated endometrial, ovarian and breast cancer cells that have undergone EMT. Restoration of miR-200c to TNBC cells leads to a decrease in the mRNA and protein levels of these targets. We have made the novel discovery that breast and gynecological cancers that have undergone EMT are resistant to anoikis (death by detachment) and that restoration of miR-200c restores anoikis sensitivity to these cells. Anoikis resistance is a relatively understudied step in the metastatic cascade. Interestingly, both TrkB and its ligand NTF3 (as measured by western blot and ELISA) increase when TNBC cells are forced to grow in suspension thereby setting up an inappropriate autocrine loop that enables anoikis resistance. Both the TrkB receptor and the ligand, NTF3, are repressed when miR-200c is restored to tumor cells, leading to anoikis sensitivity. When exogenous TrkB lacking its 3'UTR (such that it cannot be targeted by miR-200c) is added, miR-200c no longer reverses anoikis resistance. Thus we conclude that the inappropriate expression of TrkB and NTF3 (which are normally expressed in neurons) in tumor cells sets up an autocrine loop resulting in anoikis resistance, but this process can be reversed by restoration of miR-200c. We will also discuss how miR-200c enhance chemosensitivity via targeting of class III beta-tubulin and demonstrate that miR-200c reduces tumor burden in an in vivo model of ovarian cancer. Funding source: DOD Breast Cancer Program Idea Award BC084162 and Susan G. Komen Foundation Award KG090415 and the Colorado Cancer League to JKR. (poster)

Les adénocarcinomes nasosinusiens revisités. Intérêt pronostique de la classification histologique OMS 2005

Objectives The WHO 2005 histological classification separates sinonasal adenocarcinoma (ADC) into three classes: intestinal-type adenocarcinoma (ITAC), low-grade sinonasal ADC and high-grade sinonasal ADC. The goal of this study was to check the relevance of this classification on the prognosis of patients treated for ADC. Patients and methods All the files of patients treated consecutively in the ENT department of the Montpellier University Hospital for ADC between 1980 and 2003 were retrospectively re-examined. Each case was reviewed for anatomical and pathological data based on the immunohistochemistry results according to the WHO 2005 classification, with a study of a panel of markers: cytokeratin 7 (CK7), cytokeratin 20 (CK20), Villin, CDX2 and EGFR. The epidemiologic data, the methods of treatment and the follow-up were studied. The survival probabilities were calculated using the Kaplan-Meier method and the survival graphs were compared using a log-rank test. Results Sixty-two files were reviewed. Twelve patients were reclassified into the adenoid cystic carcinoma category and excluded from the study. In the 50 remaining cases, there were 36 ITAC cases, four low-grade ADC cases and 10 high-grade dedifferentiated carcinomas. For all of the ADC cases, the total survival at 5 years and without recurrence was 64 and 52%, respectively. The analysis of the three subgroups showed a total survival of 72.2% for ITAC, 100% for low-grade and 20% for high-grade ADC with a significant difference ( p = 0.044). This immunohistochemical distinction was mainly based on the expression of CK20 found in 98% of the ITAC cases and absent in low- and high-grade ADC patients. Conclusion The WHO 2005 classification for sinonasal ADC provides a valuable prognosis by showing a difference in the progression profile between ITAC, low-grade ADC and high-grade ADC. Moreover, broader studies should be conducted to investigate the different subtypes of ITAC.

Linking altered cell motility and proteolytic activity to tumor invasion—An active role of CD97 in tumor progression

10103 Background: Tumor cells at the invasion front of several carcinomas differ in their molecule pattern from cells in central tumor regions. As recently shown by us, this includes the cell surface receptor CD97 (Am J Pathol 2002,161:1657–67). Here, we link related differences in cell biological and biomechanical properties to the characteristics of tumor invasion. We combine in vitro and in vivo experiments with computer simulations of tumor progression and analyze the particular role of CD97 in this process. Methods: We compared the cDNA pattern of clones with adjustable expression of normal or C- terminal truncated CD97 using microarrays and confirmed the results at the protein level. Clonal cell motility was analyzed by time-lapse video microscopy. The scid mouse model was used to monitor tumor growth in vivo. Additionally, we introduce a novel class of individual cell-based computer models of tumor invasion into stroma. The approach enables us to analyze the impact of different cellular alterations on the organization and dynamics of the tumor invasion front and we can study several assumptions about the origin of these alterations. Results: CD97 overexpression stimulates single cell motility and increases proteolytic activity and IL-8 secretion in vitro and promotes growth of tumors in scid mice. In contrast, tumor cells overexpressing truncated CD97 show lower proteolytic activity, impaired in vitro motility and in vivo tumor growth. By computer simulation studies we demonstrate that the observed effects induced by CD97 can strongly increase the invasion capacity of tumors. Furthermore, they can cause a specific morphology of the invasion front which is known to correlate with poor prognosis. Thus, as a consequence of our computer simulations and findings in vitro and in vivo, we suggest that CD97 plays an active role in the propagation of de-differentiated carcinomas. Conclusions: Our combined experimental and theoretical computer analysis provides a novel insight in how variations of individual cell properties can be linked to different patterns of tumor cell invasion. Our results suggest that proteolytic activity at the tumor front in conjunction with elevated and directed cell motility are key steps to aggressive tumor invasion. No significant financial relationships to disclose.