POLE mutation combined with microcystic, elongated and fragmented (MELF) pattern invasion in endometrial carcinomas might be associated with poor survival in Chinese women

Enhancing prognostic insights: myometrial invasion patterns in endometrial carcinoma, with emphasis on MELF pattern-a comprehensive review and meta-analysis

PURPOSE

The microcystic, elongated, and fragmented (MELF) pattern, characterized by myxoid and inflamed stroma, is readily identifiable as a form of myometrial infiltration. This meta-analysis endeavors to assess the prognostic significance of MELF infiltration patterns in patients diagnosed with endometrial cancer.

METHODS

A comprehensive literature search, spanning until 11 October 2023, across PubMed, Embase, Cochrane, and Web of Science databases, identified 23 relevant studies involving 5199 patients. Data analysis was performed using Stata 16.0.

RESULTS

Analysis indicates that MELF infiltration predicts a higher risk of lymph node metastasis in endometrial cancer patients [hazard ratios (HR) = 5.05; 95% confidence interval (CI), 3.62-7.05; P < 0.05]. Notably, this association remains consistent across various patient demographics, analytical approaches, study designs, and treatment modalities. However, MELF infiltration does not significantly correlate with recurrence (HR = 1.05; 95% CI, 0.73-1.52; P > 0.05), overall survival (HR = 1.24; 95% CI, 0.91-1.68; P > 0.05), or disease-free survival (HR = 1.40; 95% CI, 0.85-2.28; P > 0.05).

CONCLUSION

While MELF infiltration heightens the risk of lymph node metastasis in endometrial cancer, its impact on recurrence, overall survival, and disease-free survival remains statistically insignificant.

Molecular Classification of Endometrial Endometrioid Carcinoma With Microcystic Elongated and Fragmented Pattern

The studies on the molecular classification of endometrioid carcinoma (EC) with microcystic, elongated, and fragmented (MELF) pattern invasion are limited. In this study, 77 cases of ECs with MELF patterns in Chinese women were collected. The molecular classification of the fifth edition of the World Health Organization was used to classify the molecular subtypes using immunohistochemistry staining (mismatch repair [MMR]-immunohistochemistry: MSH2, MSH6, MLH1, and PMS2; p53) and Sanger sequencing targeted POLE . The results showed that the prevalence of the 4 molecular subtypes in EC with MELF pattern was 6.5% (5/77) for POLE mutation, 20.8% (16/77) for MMR deficient, 11.7% (9/77) for p53-mutant, and 61.0% (47/77) for no specific molecular profile. The clinicopathological characteristics of each subtype were compared. The p53-mutant and no specific molecular profile subgroups were associated with higher International Federation of Gynecology and Obstetrics stage and International Federation of Gynecology and Obstetrics grade, deeper myometrial invasion, lymphovascular space invasion, lymph node metastasis, and absence of tumor-infiltrating lymphocytes, whereas the POLE mutation and MMR deficient subgroups were associated with lower aggressive features and prominent tumor-infiltrating lymphocytes. Progression-free survival showed that the p53-mutant and no specific molecular profile subgroups had a poorer prognosis than the POLE mutation and MMR deficient subgroups. However, lymph node metastasis was an independent factor associated with a higher risk of disease recurrence in multivariate analysis. In conclusion, ECs with MELF patterns can be divided into 4 molecular subtypes with discrepancies in aggressive clinicopathological characteristics and tumor-infiltrating lymphocytes. Molecular classification has clinical significance in a morpho-molecular approach for ECs with MELF patterns.

High prevalence of "non-pathogenic" POLE mutation with poor prognosis in a cohort of endometrial cancer from South India

OBJECTIVE

The Cancer Genome Atlas (TCGA) project identified favorable prognosis regarding the ultra-mutated endometrial cancer (EC) subtype linked to polymerase epsilon gene (POLE) mutations. This study investigated POLE mutations in EC of Indian patients.

METHODS

This retrospective analytical study was conducted between January 2016 and January 2023 at the Government Medical College, Kozhikode, and the MVR Cancer Center, Kozhikode, Kerala. Sanger sequencing of POLE gene exons 9 and 13 in 151 EC patients was carried out to analyze the relationship between mutations and epidemiological factors, clinicopathologic features, and treatment outcomes.

RESULTS

Among 151 cases enrolled, 39 were unique POLE-mutated cases. Significant associations were high-grade tumors, myometrial invasion >50%, and Lymph-vascular space invasion (LVSI). The median follow-up was 40 months (95% confidence interval [CI], 34-46). A lower mean disease-specific survival (DSS) of 51.7 months (95% CI, 43.7-59.6) was noted in the POLE-mutated group compared with 72.11 months (95% CI, 67.60-76.62) for the POLE wild-type. A statistically significant hazard ratio (HR) of 2.683 for DSS in the POLE-mutated group was noted. In advanced stages (FIGO stages II-IV), a nine-fold HR for DSS and overall survival (OS) compared with POLE wild-type was identified. After controlling for treatment effects using Cox proportional HR, advanced-stage POLE-mutated tumors had a significantly higher HR of 8.67 for DSS compared with POLE-wild-type tumors of the same stage.

CONCLUSION

This study identified a unique set of POLE mutations in Indian EC patients associated with poor prognosis, which were particularly pronounced in advanced stages. Advanced stage of presentation, type of POLE mutations, and possibly ethnicity are predictors of adverse outcomes in POLE-mutated EC. The present study highlights ethnicity as a determinant of phenotypic expression of genetic change.

Prognosis of polymerase epsilon (POLE) mutation in high-grade endometrioid endometrial cancer: Systematic review and meta-analysis

BACKGROUND

POLE mutated endometrial carcinomas may represent a subspecific type of tumors harboring a more favorable prognosis. Grade 3 (G3 or high-grade) endometrioid endometrial carcinomas remain a clinical dilemma, with some tumors behaving as the low-grade counterparts and others presenting a more aggressive behavior.

OBJECTIVES

To determine the association between POLE mutational status and the overall-survival (OS) and progression-free-survival (PFS) of patients with G3 endometrioid endometrial cancer (EC). We also aimed to determine the prevalence of POLE mutations in G3 endometrioid EC.

METHODS

We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO No: CRD4202340008). We searched the following electronic databases: PubMed/Medline, EMBASE, Cochrane Library, Scopus, and Web of Science. For time-to-event data, the effect of POLE mutation in G3 EC was described using hazard ratios (HRs) and corresponding 95% confidence intervals (CIs). Individual patient data for each study was investigated if available from the study authors. If individual patient data were not available, information regarding time-to-event outcomes was extracted using an appropriate methodology. OS and PFS were analyzed using both one-stage and two-stage approaches, the Kaplan-Meier method, and Cox-proportional hazards models.

RESULTS

This systematic review and meta-analysis included 19 studies with 3092 patients who had high-grade endometrioid EC. Patients with POLE mutations had lower risks of death (HR = 0.36, 95% CI 0.26 to 0.50, I2 = 0%, 10 trials) and disease progression (HR = 0.31, 95% CI 0.17 to 0.57, I2 = 33%, 10 trials). The pooled prevalence of POLE mutation was 11% (95% CI 9 to 13, I2 = 68%, 18 studies).

CONCLUSION

POLE mutations in high-grade endometrioid EC are associated with a more favorable prognosis with increased OS and PFS.

Predictive and prognostic biomarkers in female genital tract tumours: an update highlighting their clinical relevance and practical issues

The evaluation of biomarkers by molecular techniques and immunohistochemistry has become increasingly relevant to the treatment of female genital tract tumours as a consequence of the greater availability of therapeutic options and updated disease classifications. For ovarian cancer, mutation testing for BRCA1/2 is the standard predictive biomarker for poly(ADP-ribose) polymerase inhibitor therapy, while homologous recombination deficiency testing may allow the identification of eligible patients among cases without demonstrable BRCA1/2 mutations. Clinical recommendations are available which specify how these predictive biomarkers should be applied. Mismatch repair (MMR) protein and folate receptor alpha immunohistochemistry may also be used to guide treatment in ovarian cancer. In endometrial cancer, MMR immunohistochemistry is the preferred test for predicting benefit from immune checkpoint inhibitor (ICI) therapy, but molecular testing for microsatellite instability may have a supplementary role. HER2 testing by immunohistochemistry and in situ hybridisation is applicable to endometrial serous carcinomas to assess trastuzumab eligibility. Immunohistochemistry for oestrogen receptor and progesterone receptor expression may be used for prognostication in endometrial cancer, but its predictive value for hormonal therapy is not yet proven. POLE mutation testing and p53 immunohistochemistry (as a surrogate for TP53 mutation status) serve as prognostic markers for favourable and adverse outcomes, respectively, in endometrial cancer, especially when combined with MMR testing for molecular subtype designation. For cervical cancer, programmed death ligand 1 immunohistochemistry may be used to predict benefit from ICI therapy although its predictive value is under debate. In vulvar cancer, p16 and p53 immunohistochemistry has established prognostic value, stratifying patients into three groups based on the human papillomavirus and TP53 mutation status of the tumour. Awareness of the variety and pitfalls of expression patterns for p16 and p53 in vulvar carcinomas is crucial for accurate designation. It is hoped that collaborative efforts in standardising and optimising biomarker testing for gynaecological tumours will contribute to evidence-based therapeutic decisions.

Prognostic value of lymphovascular space invasion according to the molecular subgroups in endometrial cancer

OBJECTIVE

Lymphovascular space invasion (LVSI) is a known prognostic factor for oncological outcome in endometrial cancer patients. However, little is known about the prognostic value of LVSI among the different molecular subgroups. The aim of this study was to determine the prognostic dependence of LVSI from the molecular signature.

METHODS

This study included endometrial cancer patients who underwent primary surgical treatment between February 2004 and February 2016 at the Karolinska University Hospital, Sweden and the Bern University Hospital, Switzerland (KImBer cohort). All cases had complete molecular analysis performed on the primary tumor according to the WHO Classification of Tumors, 5th edition. LVSI was reviewed by reference pathologists for all pathology slides.

RESULTS

A total of 589 endometrial cancer patients were included in this study, consisting of 40 POLEmut (polymerase epsilon ultramutated), 198 MMRd (mismatch repair deficient), 83 p53abn (p53 abnormal), and 268 NSMP (non-specific molecular profile) cases. Altogether, 17% of tumors showed LVSI: 25% of the POLEmut, 19% of the MMRd, 30% of the p53abn, and 10% of the NSMP cases. There was a significant correlation of LVSI with lymph node metastasis in the entire study cohort (p<0.001), remaining significant in the MMRd (p=0.020), p53abn (p<0.001), and NSMP (p<0.001) subgroups. Mean follow-up was 89 months (95% CI 86 to 93). The presence of LVSI significantly decreased recurrence-free survival among patients with MMRd, p53abn, and NSMP endometrial cancer, and overall survival in patients with p53abn and NSMP tumors. In patients with NSMP endometrial cancer, evidence of substantial LVSI remained a significant independent predictor of recurrence in multivariable Cox regression analysis including tumor stage and grade (HR 7.5, 95% CI 2.2 to 25.5, p=o.001).

CONCLUSION

The presence of LVSI was associated with recurrence in each subgroup of patients with MMRd, p53abn, and NSMP endometrial cancer, and LVSI remained an independent predictor of recurrence in NSMP endometrial cancer patients.

Can the microcystic, elongated and fragmented pattern of invasion influence the evaluation of the depth of myometrial invasion in low-grade endometrioid endometrial cancer using imaging techniques?

Objectives

The microcystic, elongated and fragmented pattern of invasion can be associated with an underestimation of the depth of myometrial invasion by imaging techniques. We aimed to evaluate the influence of microcystic, elongated and fragmented pattern of invasion in the diagnostic performance of transvaginal ultrasound scan and magnetic resonance imaging for the prediction of the depth of myometrial invasion in low-grade endometrioid endometrial carcinomas.

Methods

Prospective and consecutive study including all low-grade (G1-G2) endometrioid endometrial carcinomas diagnosed between October 2013 and July 2018 in a tertiary hospital. Preoperative staging was performed with transvaginal ultrasound scan and/or magnetic resonance imaging followed by surgical staging. Final histology was considered as the reference standard. Sensitivity, specificity and diagnostic accuracy for the prediction of depth of myometrial invasion was calculated for both imaging techniques. The STARD 2015 guidelines were used.

Results

A total of 136 patients were consecutively included. Transvaginal ultrasound scan was performed in 132 patients and magnetic resonance imaging in 119 patients. The diagnostic accuracy of transvaginal ultrasound scan for the prediction of depth of myometrial invasion in the microcystic, elongated and fragmented negative group (82% (95% confidence interval = 73-88)) was higher compared to the microcystic, elongated and fragmented positive group (61% (95% confidence interval = 36-83)). The diagnostic accuracy of magnetic resonance imaging was also higher in the microcystic, elongated and fragmented negative group (80% (95% confidence interval = 71-87)) compared to the microcystic, elongated and fragmented positive (47% (95% confidence interval = 21-73)).

Conclusions

In low-grade endometrioid endometrial carcinomas with a positive microcystic, elongated and fragmented pattern of invasion, the evaluation of the depth of myometrial invasion using transvaginal ultrasound scan and magnetic resonance imaging may be underestimated.

Re-stratification of patients with copy-number low endometrial cancer by clinicopathological characteristics

OBJECTIVE

To stratify patients with copy-number low (CNL) endometrial cancer (EC) by clinicopathological characteristics.

METHODS

EC patients who underwent surgery between June 2018 and June 2022 at Peking University People's Hospital were included and further classified according to TCGA molecular subtyping: POLE ultramutated, microsatellite instability high (MSI-H), CNL, and copy-number high (CNH). Clinicopathological characteristics and prognosis of CNL patients were retrospectively reviewed. The Cox proportional hazards regression model was applied to perform univariate and multivariate analysis, and independent risk factors were identified. Differentially expressed genes (DEGs) according to overall survival (OS) were screened based on the transcriptome of CNL cases from the TCGA program. Finally, a nomogram was established, with an accuracy analysis performed.

RESULTS

(1) A total of 279 EC patients were included, of whom 168 (60.2%) were in the CNL group. A total of 21 patients had recurrence and 6 patients deceased, and no significant difference in recurrence-free survival (RFS) was exhibited among the four molecular subtypes (P = 0.104), but that in overall survival (OS) was statistically significant (P = 0.036). (2) CNL patients were divided into recurrence and non-recurrence groups, and significant differences (P < 0.05) were found between the two groups in terms of pathological subtype, FIGO stage, ER, PR, glycated hemoglobin (HbA1c), and high-density lipoprotein cholesterol (HDL-C). All the above factors were included in univariate and multivariate Cox regression models, among which pathological subtype, PR, and HDL-C were statistically different (P < 0.05), resulting in three independent risk factors for the prognosis of patients in the CNL group. (3) By comparing the transcriptome of tumor tissues between living and deceased CNL patients from the TCGA database, 903 (4.4%) DEGs were screened, with four lipid metabolism pathways significantly enriched. Finally, a nomogram was established, and internal cross-validation was performed, showing good discrimination accuracy with an AUC of 0.831 and a C-index of 0.748 (95% CI 0.444-1.052). (4) According to the established nomogram and the median total score (85.89), patients were divided into the high score group (n = 85) and low score group (n = 83), and the 8 patients with recurrence were all in the high score group. Survival analysis was performed between the two groups, and the difference in RFS was statistically significant (P = 0.010).

CONCLUSION

In the CNL group of EC patients, pathological subtype, PR, and HDL-C were independent prognostic risk factors, the nomogram established based upon which had a good predictive ability for the recurrence risk of patients with CNL EC.

The role of TCGA molecular classification in clear cell endometrial carcinoma

Clear cell endometrial carcinoma (CCEC) represents a relatively rare and heterogeneous entity. Based on The Cancer Genome Atlas (TCGA) molecular classification, the risk stratification and management of endometrial cancer (EC) have been improved. Although the relationship of CCEC with the TCGA classification is less well understood, data has emerged to suggest that molecular classification plays an important role in the prognosis and management of CCEC. Most of patients with CCEC are characterized by p53abn or NSMP type and the prognosis of these patients is poor, whereas those with MMRd or POLEmut seem to have a favorable prognosis. Adjuvant therapy is recommended in CCEC with p53abn and NSMP. Advanced/recurrent CCEC with MMRd benefit much more from immune checkpoint inhibitors after the failure of platinum-based chemotherapy. In addition, bevacizumab plus chemotherapy upfront seems to improve outcomes of advanced/recurrent patients whose tumors harbored mutated TP53, including CCECs with p53abn. Further studies which exclusively recruit CCEC are urgently needed to better understand the role of molecular classification in CCEC. This review will provide an overview of our current understanding of TCGA classification in CCEC.

Endometrial carcinomas with dyshesive, eosinophilic, and vacuolated (histiocyte-like) tumor cells: a reactive-like phenotype associated with aggressive behavior

Herein, we present a clinicopathological and molecular analysis of four cases of endometrial carcinoma (EC) diffusely exhibiting dyshesive cells with wide eosinophilic and vacuolated cytoplasm (histiocyte-like tumor cells, HLTCs). We compared these HLTCs to similar cells found in microcystic, elongated and fragmented (MELF) pattern (n = 20) or after neoadjuvant chemotherapy (NAC) (n = 5). The four cases were endometrioid, serous, clear cell, and gastric-type; all were at FIGO stage ≥ III. HLTCs showed an epithelial Müllerian phenotype and at least focal CK20, HNF1β, and CK5/6 expression, with aberrant e-cadherin and β-catenin expression; two cases were MMR-deficient, and one was p53-abnormal; all were POLE wild type. MELF-associated and NAC-associated HLTCs showed similar morphological/immunophenotypical features. However, MELF-associated HLTCs were mainly intraglandular and inflammation-associated, did not form a distinct tumor component, and showed no relationship with lymph node metastases. In conclusion, different histotypes of EC may show a prominent HLTC component, which shows peculiar morphological/immunophenotypical features and appears associated with aggressive behavior.

Integration of Molecular Data in the Prognostic Stratification and Management of Endometrial Carcinoma

In the last years, the TCGA-based molecular classifier have been progressively integrated in the management of endometrial carcinoma. While molecular assays are increasingly available across pathology laboratories, the additional costs will expectedly be compensated by a reduction in overtreatments and a prevention of recurrences. The additional time might be shortened by assessing molecular markers on biopsy specimens. Retrospective data suggest that the molecular classifier will have a major impact of on the risk stratification, with many patients having their risk class down- or upstaged based on POLE mutations or p53 abnormalities, respectively. However, there are still several issues to be resolved, such as the prognostic value of the TCGA classifier in each FIGO stage, or the type of adjuvant treatment most suitable for each molecular group. Other issues regard the prognostic stratification of the mismatch repair-deficient and "no specific molecular profile" groups, which currently follows the same criteria; however, the former seems to be prognostically consistent regardless of FIGO grade and histotype, whereas the latter appears highly heterogeneous. Numerous clinical, histological, immunohistochemical and molecular markers have been proposed to refine the TCGA classification, but their prognostic value is still undefined. Hopefully, prospective data collected in the next years will help resolving these issues.

The clinicopathological characteristics of POLE-mutated/ultramutated endometrial carcinoma and prognostic value of POLE status: a meta-analysis based on 49 articles incorporating 12,120 patients

Objective

This study was designed to investigate the frequency and clinicopathological characteristics of POLE-mutated/ultramutated (POLEmut) in endometrial carcinoma (EC) and assess the prognostic values of POLE status.

Methods

Electronic databases were screened to identify relevant studies. Meta-analysis was used to yield the pooled frequency of POLEmut and prognostic parameters by 95% confidence interval (CI), odd ratio (OR), and hazard ratio (HR).

Results

Totally, 12,120 EC patients from 49 studies were included. The pooled frequency of POLEmut was 7.95% (95% CI: 6.52–9.51%) in EC, 7.95% (95% CI: 6.55–9.46%) in endometrioid endometrial carcinoma, and 4.45% (95% CI: 2.63–6.61%) in nonendometrioid endometrial carcinoma. A higher expression occurred in grade 3 (OR = 0.51, 95% CI: 0.36–0.73, P = 0.0002), FIGO stage I-II (OR = 1.91, 95% CI: 1.29–2.83, P = 0.0013), and myometrial invasion< 50% (OR = 0.66, 95% CI: 0.50–0.86, P = 0.0025). Survival analyses revealed favorable OS (HR = 0.68, 95% CI: 0.55–0.85, P = 0.0008), PFS (HR = 0.74, 95% CI: 0.59–0.93, P = 0.0085), DSS (HR = 0.61, 95% CI: 0.44–0.83, P = 0.0016), and RFS (HR = 0.47, 95% CI: 0.35–0.61, P <  0.0001) for POLEmut ECs. Additionally, the clinical outcomes of POLEmut group were the best, but those of p53-abnormal/mutated (p53abn) group were the worst, while those of microsatellite-instable (MSI)/hypermutated group and p53-wild-type (p53wt) group were medium.

Conclusions

The POLEmut emergered higher expression in ECs with grade 3, FIGO stage I-II, and myometrial invasion< 50%; it might serve as a highly favorable prognostic marker in EC; the clinical outcomes of POLEmut group were the best one among the four molecular subtypes.

Microcystic, elongated and fragmented (MELF) pattern in endometrial carcinoma: clinicopathologic analysis and prognostic implications

To assess the clinical value of microcystic, elongated, and fragmented (MELF) pattern in Chinese patients with endometrial endometrioid carcinoma. A total of 189 patients with endometrial endometrioid carcinoma were retrospectively analyzed in Peking University Third Hospital from January 2017 to December 2019. We analyzed the association of MELF pattern with the histopathologic data and prognosis of the patients, while immunohistochemistry was performed. The frequency of MELF pattern was 17.99% (34/189). MELF pattern was associated significantly with tumor size, myometrial invasion, histological grade, International Federation of Gynecology and Obstetrics stages, lymphovascular space invasion, and lymph node metastasis. According to multivariate logistic regression analysis, lymphovascular space invasion [95% confidence interval 1.021-48.485, P = .048] was a significant predictor of lymph node involvement. However, MELF pattern was not a significant predictor (95% confidence interval 0.054-2.279, P = .400). Loss of expression for mismatch repair proteins was observed in 10 MELF + cases (29.41%) and 54 MELF- cases (34.84%), respectively. All patients were followed up for 36.8 ± 8.9 months (18-54 months). Only 1 patient with MELF pattern was diagnosed with vaginal recurrence 28 months after the surgery. MELF pattern was associated with adverse histologic findings in endometrial endometrioid carcinomas. However, MELF pattern was statistically not a valuable predictor of lymph node metastasis and it needs more studies to show whether MELF pattern has an impact on the prognosis of patients with endometrial endometrioid carcinoma. MELF pattern may be important for identifying those patients who need comprehensive staging surgery.

The evolving role of morphology in endometrial cancer diagnostics: From histopathology and molecular testing towards integrative data analysis by deep learning

Endometrial cancer (EC) diagnostics is evolving into a system in which molecular aspects are increasingly important. The traditional histological subtype-driven classification has shifted to a molecular-based classification that stratifies EC into DNA polymerase epsilon mutated (POLEmut), mismatch repair deficient (MMRd), and p53 abnormal (p53abn), and the remaining EC as no specific molecular profile (NSMP). The molecular EC classification has been implemented in the World Health Organization 2020 classification and the 2021 European treatment guidelines, as it serves as a better basis for patient management. As a result, the integration of the molecular class with histopathological variables has become a critical focus of recent EC research. Pathologists have observed and described several morphological characteristics in association with specific genomic alterations, but these appear insufficient to accurately classify patients according to molecular subgroups. This requires pathologists to rely on molecular ancillary tests in routine workup. In this new era, it has become increasingly challenging to assign clinically relevant weights to histological and molecular features on an individual patient basis. Deep learning (DL) technology opens new options for the integrative analysis of multi-modal image and molecular datasets with clinical outcomes. Proof-of-concept studies in other cancers showed promising accuracy in predicting molecular alterations from H&E-stained tumor slide images. This suggests that some morphological characteristics that are associated with molecular alterations could be identified in EC, too, expanding the current understanding of the molecular-driven EC classification. Here in this review, we report the morphological characteristics of the molecular EC classification currently identified in the literature. Given the new challenges in EC diagnostics, this review discusses, therefore, the potential supportive role that DL could have, by providing an outlook on all relevant studies using DL on histopathology images in various cancer types with a focus on EC. Finally, we touch upon how DL might shape the management of future EC patients.

L1CAM Expression in Microcystic, Elongated, and Fragmented (MELF) Glands Predicts Lymph Node Involvement in Endometrial Carcinoma

In endometrial carcinoma, both L1CAM overexpression and microcystic, elongated and fragmented (MELF) patterns of invasion have been related to epithelial-to-mesenchymal transition and metastatic spread. We aimed to assess the association between L1CAM expression, the MELF pattern, and lymph node status in endometrial carcinoma. Consecutive cases of endometrial carcinoma with MELF pattern were immunohistochemically assessed for L1CAM. Inclusion criteria were endometrioid-type, low-grade, stage T1, and known lymph node status. Uni- and multivariate logistic regression were used to assess the association of L1CAM expression with lymph node status. Fifty-eight cases were included. Most cases showed deep myometrial invasion (n = 42, 72.4%) and substantial lymphovascular space invasion (n = 34, 58.6%). All cases were p53-wild-type; 17 (29.3%) were mismatch repair-deficient. Twenty cases (34.5%) had positive nodes. No cases showed L1CAM positivity in ≥10% of the whole tumor. MELF glands expressed L1CAM at least focally in 38 cases (65.5%). L1CAM positivity in ≥10% of the MELF component was found in 24 cases (41.4%) and was the only significant predictor of lymph node involvement in both univariate (p < 0.001) and multivariate analysis (p < 0.001). In conclusion, L1CAM might be involved in the development of the MELF pattern. In uterine-confined, low-grade endometrioid carcinomas, L1CAM overexpression in MELF glands may predict lymph node involvement.

Microcystic elongated and fragmented (MELF) pattern of invasion: Molecular features and prognostic significance in the PORTEC-1 and -2 trials

OBJECTIVE

Microcystic, elongated fragmented (MELF) pattern of myometrial invasion is a distinct histologic feature occasionally seen in low-grade endometrial carcinomas (EC). The prognostic relevance of MELF invasion was uncertain due to conflicting data, and it had not yet appropriately been studied in the context of the molecular EC classification. We aimed to determine the relation of MELF invasion with clinicopathological and molecular characteristics, and define its prognostic relevance in early-stage low/intermediate risk EC.

METHODS

Single whole tumor slides of 979 (85.8%) out of 1141 (high)intermediate-risk EC of women who participated in the PORTEC-1/-2 trials were available for review. Clinicopathological and molecular features were compared between MELF invasion positive and negative cases. Time-to-event analyses were done by Kaplan-Meier method, log-rank tests and Cox' proportional hazards models.

RESULTS

MELF invasion was found in 128 (13.1%) cases, and associated with grade 1-2 histology, deep myometrial invasion and substantial lymph-vascular space invasion (LVSI). 85.6% of MELF invasion positive tumors were no-specific-molecular-profile (NSMP) EC. NSMP EC with MELF invasion were CTNNB1 wild type in 92.2% and KRAS mutated in 24.4% of cases. Risk of recurrence was lower for MELF invasion positive as compared to MELF invasion negative cases (4.9% vs. 12.7%, p = 0.026). However, MELF invasion had no independent impact on risk of recurrence (HR 0.65, p = 0.30) after correction for clinicopathological and molecular factors.

CONCLUSIONS

MELF invasion has no independent impact on risk of recurrence in early-stage EC, and is frequently observed in low-grade NSMP tumors. Routine assessment of MELF invasion has no clinical implications and is not recommended.

Bone Metastases of Endometrial Carcinoma Treated by Surgery: A Report on 13 Patients and a Review of the Medical Literature

BACKGROUND

The aim of this study was to describe the clinicopathological features of endometrial cancer (EC) patients with bone metastases treated with surgery and to systematically review the literature.

METHODS

We performed a retrospective study to include patients with bone metastases of EC at Peking University People's Hospital from 2000 to 2019. Clinicopathological features and survival outcomes were collected.

RESULTS

Among the 1662 patients with EC, 14 (0.84%) were identified with bone metastases, and all were treated surgically. Thirteen cases were analyzed. Four had bone metastases when diagnosed, and the remaining nine cases had bone metastases when first relapsed, with a median time to recurrence of 13 months (range, 5-144). The median age of the 13 patients was 58 years old (range, 45-76). Twelve were endometrioid carcinoma. The majority of sites of bone metastases were the pelvis, followed by the spine. The median overall survival (OS) was 57 months. We further combined the 13 patients with another 24 cases identified from literature research. There was no significant difference in clinicopathological characteristics between the patients with bone metastases when diagnosed and when they first relapsed. The median OS was numerically longer for patients with bone metastases when diagnosed than when they first relapsed (57 vs. 36 months, p = 0.084).

CONCLUSIONS

Patients with bone metastases of EC might benefit from comprehensive treatment based on surgery, as symptoms can be palliated and survival can probably be extended.

Protumorigenic Role of Elevated Levels of DNA Polymerase Epsilon Predicts an Immune-Suppressive Microenvironment in Clear Cell Renal Cell Carcinoma

Increasing evidence indicates that DNA polymerase epsilon (POLE), which mediates DNA damage repair, is significantly associated with tumor prognosis. This study aimed to analyze POLE expression in tumor samples and its prognostic value for patients with clear cell renal cell carcinoma (ccRCC). We found significantly elevated POLE expression in ccRCC tissues compared with normal tissues of multiple independent cohorts. The POLE expression levels of 523 patients with ccRCC (The Cancer Genome Atlas RNA-seq data) and 179 patients with ccRCC with immunohistochemical data (Fudan University Shanghai Cancer Center) were analyzed to investigate the prognostic implications of POLE expression. Cox regression analyses were implemented to explore the effect of POLE expression on the prognosis of pan-cancer. These findings revealed that elevated POLE expression levels significantly correlated with shorter overall survival (p < 0.001, n = 701) of patients with ccRCC. These data indicate that POLE expression may serve as a prognostic biomarker for cancers. Although POLE mutations were not significantly associated with survival benefits conferred upon patients with ccRCC, a CD4⁺ T cell-regulated immune microenvironment was significantly activated. Moreover, we found that POLE expression in cancers significantly correlated with an immunosuppressive tumor microenvironment, higher intratumoral heterogeneity, and expression of immune checkpoint genes PDCD1, CTLA4, and CD86, possibly mediated via the JAK/STAT and Notch signaling pathways. In conclusion, the present study is the first to our knowledge to indicate that elevated POLE expression is significantly associated with poor survival and an immune-suppressive tumor microenvironment in ccRCC. These findings suggest that POLE can serve as a biomarker for guiding molecular diagnosis and facilitating the development of novel individual therapeutic strategies for patients with advanced ccRCC.

Classification Systems of Endometrial Cancer: A Comparative Study about Old and New

Endometrial cancer is the most common gynecological malignancy of the female reproductive organs. Historically it was divided into type I and type II, until 2013 when the Cancer Genome Atlas molecular classification was proposed. Here, we applied the different classification types on our endometrial cancer patient cohort in order to identify the most predictive one. We enrolled 117 endometrial cancer patients available for the study and collected the following parameters: age, body mass index, stage, menopause, Lynch syndrome status, parity, hypertension, type of localization of the lesion at hysteroscopy, type of surgery and complications, and presence of metachronous or synchronous tumors. The tumors were classified according to the European Society for Medical Oncology, Proactive Molecular Risk Classifier for Endometrial Cancer, Post-Operative Radiation Therapy in Endometrial Carcinoma, and Cancer Genome Atlas classification schemes. Our data confirmed that European Society for Medical Oncology risk was the strongest predictor of prognosis in our cohort. The parameters correlated with poor prognosis were the histotype, FIGO stage, and grade. Our study cohort shows that risk stratification should be based on the integration of histologic, clinical, and molecular parameters.

Uterine carcinosarcoma vs endometrial serous and clear cell carcinoma: A systematic review and meta-analysis of survival

Background

It is unclear whether uterine carcinosarcoma (UCS) is more aggressive than endometrial serous carcinoma (SC) and clear cell carcinoma (CCC).

Objectives

To compare the prognosis of UCS to that of endometrial SC and CCC, through a systematic review and meta‐analysis.

Methods

Four electronic databases were searched from January 2000 to October 2020. All studies assessing hazard ratio (HR) for death in UCS vs SC and/or CCC. HRs for death with 95% confidence interval were extracted and pooled by using a random‐effect model. A significant P‐value <0.05 was adopted.

Results

Six studies with 11 029 patients (4995 with UCS, 4634 with SC, 1346 with CCC and 54 with either SC or CCC) were included. UCS showed a significantly worse prognosis than SC/CCC both overall (HR = 1.51; P = 0.008) and at early stage (HR = 1.58; P < 0.001). Similar results were found for UCS vs SC (HR = 1.53; P < 0.001) and UCS vs CCC (HR = 1.60; P < 0.001).

Conclusions

Compared to SC and CCC, UCS has a significantly worse prognosis, with a 1.5–1.6‐fold increased risk of death. This might justify a more aggressive treatment for UCS compared to SC and CCC. Further studies are necessary to define the prognostic impact of different molecular subgroups.

Uterine carcinosarcoma shows worse prognosis than serous and clear cell carcinoma; this could impact patient management.

Patterns of Myometrial Invasion in Endometrial Adenocarcinoma with Emphasizing on Microcystic, Elongated and Fragmented (MELF) Glands Pattern: A Narrative Review of the Literature

Endometrioid endometrial adenocarcinoma (EEC) is the most common malignancy of the female genital tract. According to the 2009 FIGO staging system, the depth of myometrial invasion (MI), and tumor spread to adjacent organs or tissues are the staging criteria for endometrial carcinoma (EC). Therefore, assessment of the depth of MI is of great importance. There is a spectrum of morphological patterns of MI. Still, their number and features vary according to the scientific literature, with a certain overlap that creates difficulties and controversies in the precise assessment of MI depth. The purpose of this review is to present and discuss the most important and recent information about patterns of MI, focusing on the more aggressive and the elongated and fragmented glands (MELF) pattern in particular. Assessment of MI depth and correct staging of EC is possible only after the precise recognition of each MI pattern.

Evaluation of treatment effects in patients with endometrial cancer and POLE mutations: An individual patient data meta-analysis

BACKGROUND

Endometrial cancers (ECs) with somatic mutations in DNA polymerase epsilon (POLE) are characterized by unfavorable pathological features, which prompt adjuvant treatment. Paradoxically, women with POLE-mutated EC have outstanding clinical outcomes, and this raises concerns of overtreatment. The authors investigated whether favorable outcomes were independent of treatment.

METHODS

A PubMed search for POLE and endometrial was restricted to articles published between March 1, 2012, and March 1, 2018, that provided individual patient data (IPD), adjuvant treatment, and survival. Following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) reporting guidelines for IPD, the authors used univariate and multivariate one-stage meta-analyses with mixed effects Cox models (random effects for study cohorts) to infer the associations of treatment, traditional prognostic factors, and outcome, which was defined as the time from first diagnosis to any adverse event (progression/recurrence or death from EC).

RESULTS

Three hundred fifty-nine women with POLE-mutated EC were identified; 294 (82%) had pathogenic mutations. Worse outcomes were demonstrated in patients with nonpathogenic POLE mutations (hazard ratio, 3.42; 95% confidence interval, 1.47-7.58; log-rank P < .01). Except for stage (P < .01), traditional prognosticators were not associated with progression/recurrence or death from disease. Adverse events were rare (11 progressions/recurrences and 3 disease-specific deaths). Salvage rates in patients who experienced recurrence were high and sustained, with 8 of 11 alive without evidence of disease (range, 5.5-14.2 years). Adjuvant treatment was not associated with outcome.

CONCLUSIONS

Clinical outcomes for ECs with pathogenic POLE mutations are not associated with most traditional risk parameters, and patients do not appear to benefit from adjuvant therapy. The observed low rates of recurrence/progression and the high and sustained salvage rates raise the possibility of safely de-escalating treatment for these patients.

LAY SUMMARY

Ten percent of all endometrial cancers have mutations in the DNA repair gene DNA polymerase epsilon (POLE). Women who have endometrial cancers with true POLE mutations experience almost no recurrences or deaths from their cancer even when their tumors appear to have very unfavorable characteristics. Additional therapy (radiation and chemotherapy) does not appear to improve outcomes for women with POLE-mutated endometrial cancer, and this supports the move to less therapy and less associated toxicity. Diligent classification of endometrial cancers by molecular features provides valuable information to inform prognosis and to direct treatment/no treatment.

Prognostic value of myometrial invasion and TCGA groups of endometrial carcinoma

BACKGROUND

2021 ESGO/ESTRO/ESP guidelines for the management of patients with endometrial carcinoma (EC) encourage molecular classification and propose a new prognostic risk stratification based on both pathologic and molecular features. Although deep myometrial invasion (DMI) has been considered as a crucial risk factor in EC, it is unclear if its prognostic value is independent from The Cancer Genome ATLAS (TCGA) groups.

AIM

To assess if the prognostic value of DMI is independent from the TCGA groups in EC patients.

MATERIALS AND METHODS

A systematic review and meta-analysis was performed by searching through 5 electronic databases, from their inception to March 2021, for all studies that allowed to assess DMI as a prognostic factor independent of the TCGA groups in EC patients. Pooled hazard ratio (HR) of DMI for overall survival (OS) and disease-free survival (DFS) was calculated at multivariable analyses including TCGA groups as a variable. Superficial myometrial invasion (<50% of myometrial thickness) was considered as a reference. In DFS analyses, locoregional and distant recurrence were separately considered for one study.

RESULTS

Five studies with 2469 patients were included in the systematic review and 3 studies with 1549 patients in the meta-analysis. Pooled HR of DMI was 1.082 (CI 95% 0.85-1.377; p = 0.524) for OS, 1.709 (CI 95% 1.173-2.491; p = 0.005) for DFS, 1.585 (CI 95% 1.154-2.178; p = 0.004) for DFS additionally considering locoregional recurrence for one study, and 1.701 (CI 95% 1.235-2.344, p = 0.001) for DFS additionally considering distant recurrence for the same study.

CONCLUSIONS

DMI does not appear as an independent prognostic factor for OS in EC patients; instead, it seems to affect the risk of recurrence independently from the TCGA groups. Further studies are necessary to confirm these findings and to assess the prognostic impact of DMI separately in each TCGA group.