Clinicopathologic Significance of Mismatch Repair Defects in Endometrial Cancer: An NRG Oncology/Gynecologic Oncology Group Study

Prognostic Effect of Mismatch Repair Status in Early-Stage Endometrial Cancer Treated With Adjuvant Radiation: A Multi-institutional Analysis

PURPOSE

The aim of this work was to report the effect of mismatch repair (MMR) status on outcomes of patients with stage I-II endometrioid endometrial adenocarcinoma (EEC) who receive adjuvant radiation therapy.

METHODS AND MATERIALS

This is a multi-institutional retrospective cohort study across 11 institutions in North America. Patients with known MMR status and stage I-II EEC status postsurgical staging were included. Overall survival (OS) and recurrence-free survival (RFS) rates were estimated via the Kaplan-Meier method. Univariable and multivariable analyses were performed via Cox proportional hazard models for RFS and OS. Statistical analyses were conducted using SPSS version 27.

RESULTS

In total, 744 patients with a median age at diagnosis of 65 years (IQR, 58-71) were included. Most patients were White (69.4%) and had Federation of Obstetrics and Gynecology 2009 stage I (84%) and Federation of Obstetrics and Gynecology grade 1 to 2 (73%). MMR deficiency was reported in 234 patients (31.5%), whereas 510 patients (68.5%) had preserved MMR. External beam radiation therapy with or without vaginal brachytherapy was delivered to 186 patients (25%), whereas 558 patients (75%) received vaginal brachytherapy alone. At a median follow-up of 43.5 months, the estimated crude OS and RFS rates for the entire cohort were 92.5% and 84%, respectively. MMR status was significantly correlated with RFS. RFS was inferior for MMR deficiency compared with preserved MMR (74.3% vs 88.6%, P < .001). However, no difference in OS was seen (90.8% vs 93.2%, P = .5). On multivariable analysis, MMR deficiency status was associated with worse RFS (hazard ratio, 1.86; P = .001) but not OS.

CONCLUSIONS

MMR status was independently associated with RFS but not OS in patients with early-stage EEC who were treated with adjuvant radiation therapy. These findings suggest that differential approaches to surveillance and/or treatment based on MMR status could be warranted.

Unsolved Issues in the Integrated Histo-Molecular Classification of Endometrial Carcinoma and Therapeutic Implications

Endometrial carcinoma (EC) is the most frequent gynecological cancer, with an increasing incidence and mortality in recent times. The last decade has represented a true revolution with the development of the integrated histo-molecular classification of EC, which allows for the stratification of patients with morphologically indistinguishable disease into groups with different prognoses. Particularly, the POLE-mutated subgroup exhibits outstanding survival. Nevertheless, the indiscriminate application of molecular classification appears premature. Its prognostic significance has been proven mainly in endometrioid EC, the most common histotype, but it has yet to be convincingly confirmed in the other minor histotypes, which indeed account for a relevant proportion of EC mortality. Moreover, its daily use both requires a mindful pathologist who is able to correctly evaluate and unambiguously report immunohistochemical staining used as a surrogated diagnostic tool and is hampered by the unavailability of POLE mutation analysis. Further molecular characterization of ECs is needed to allow for the identification of better-tailored therapies in different settings, as well as the safe avoidance of surgery for fertility preservation. Hopefully, the numerous ongoing clinical trials in the adjuvant and metastatic settings of EC will likely produce evidence to refine the histo-molecular classification and therapeutic guidelines. Our review aims to retrace the origin and evolution of the molecular classification for EC, reveal its strengths and limitations, show clinical relevance, and uncover the desired future developments.

Mismatch repair deficiency and abnormal p53 expression has significant predictive value for progesterone resistance and endometrial tumorigenesis in patients with endometrial atypical hyperplasia receiving fertility-preserving treatment

OBJECTIVE

This study aimed to evaluate the prognostic ability of mismatch repair deficiency (MMR-d) and abnormal p53 expression (p53abn) in patients with endometrial atypical hyperplasia (EAH) who underwent fertility-preserving treatment.

METHODS

This retrospective study evaluated 51 patients with EAH who underwent fertility-sparing treatment. Endometrial biopsy specimens obtained before hormone therapy were collected and used for immunohistochemical staining for MMR and p53 proteins. Response, relapse, and progression rates were assessed based on age, body mass index, diabetes, polycystic ovary syndrome, reproductive history, MMR status, and p53 status.

RESULTS

Overall, 11/51 (21.6%) patients had loss of MMR proteins and 6/51 (11.8%) had p53abn. Patients with MMR-d had lower complete response (CR) rates than those with normal staining patients at 12 months after initial treatment (p = 0.049). Patients with MMR-d had significantly higher relapse rates than those with MMR-p at the 1-year follow-ups after achieving CR (p = 0.035). Moreover, patients with MMR-d had a higher incidence of disease progression at 2, 3, and 4 years after fertility-sparing treatment (p = 0.001, p = 0.01 and p = 0.035, respectively). Patients with p53abn had higher relapse rates than those with p53wt at the 1- and 2-year follow-ups after achieving CR (p = 0.047 and p = 0.036, respectively). Moreover, patients with p53abn had a higher incidence of disease progression at 3 and 4 years after fertility-sparing treatment (p = 0.02 and p = 0.049, respectively).

CONCLUSIONS

EAH patients with MMR-d and p53abn have a significantly higher risk of disease relapse and progression. Thus, MMR-d and p53abn may be used as predictive biomarkers of progestin resistance and endometrial tumorigenesis in EAH.

Antitumor activity and safety of the PD-1 inhibitor retifanlimab in patients with recurrent microsatellite instability-high or deficient mismatch repair endometrial cancer: Final safety and efficacy results from cohort H of the POD1UM-101 phase I study

OBJECTIVE

Retifanlimab is a humanized immunoglobulin G4 monoclonal antibody against programmed death 1 being investigated in several solid tumor types. We report final results from patients with recurrent microsatellite instability-high (MSI-H)/mismatch repair deficient (dMMR) endometrial cancer treated with retifanlimab in a POD1UM-101 expansion cohort.

METHODS

Eligible patients (≥18 years; histologically proven/unresectable/recurrent, MSI-H/dMMR endometrial cancer; checkpoint inhibitor naive) received retifanlimab 500 mg intravenously every 4 weeks for ≤2 years. Primary endpoint was safety/tolerability.

RESULTS

At data cutoff (May 17, 2023), 76 patients had received at least one retifanlimab dose. Median (range) age was 67 (49-88) years; 88.2% of patients had recurrent metastatic disease and 80.3% had visceral metastases. Seventy-five patients (98.7%) had received at least one prior systemic therapy. Median retifanlimab exposure was 10.0 (0.03-25.9) months; 23 patients completed treatment. 38 patients (50.0%) had grade ≥3 treatment-emergent adverse events (TEAEs), most commonly anemia (n = 10 [13.2%]). 63 patients (82.9%) had treatment-related AEs (TRAEs; grade ≥3, n = 14 [18.4%]); most common was fatigue (n = 14 [18.4%]). Two patients had TEAEs that led to death; no TRAEs were fatal. 39 patients had objective responses (51.3%; 95% CI, 39.6-63.0%); 19 patients (25.0%) had complete response and 20 (26.3%) had partial response. Median progression-free survival was 12.2 months; 30 patients (76.9%) had duration of response (DOR) ≥12 months. Median DOR was not reached after median follow-up time of 26.0 months.

CONCLUSIONS

Retifanlimab was generally well tolerated and demonstrated encouraging anti-tumor activity in patients with pre-treated recurrent MSI-H/dMMR endometrial cancer.

Molecular characterization as new driver in prognostic signatures and therapeutic strategies for endometrial cancer

Endometrial cancer (EC) incidence and mortality rates have been increasing, particularly among young females. Although more than 90% of ECs are sporadic, 5-10% are hereditary, a majority of which occurs within Hereditary Non-Polyposis Colorectal Cancer syndrome (HNPCC) or Lynch syndrome. The traditional histopathological classification differentiates EC between two main groups: type I (or endometrioid) and type II (including all other histopathological subtypes). However, this classification lacks reproducibility and does not account for the emerging molecular heterogeneity. In 2013, The Cancer Genome Atlas (TCGA) project proposed EC molecular classification defining four groups with different prognostic and predictive values and the current international guidelines are progressively establishing EC risk stratification and treatment based on both histopathological and molecular criteria. Our manuscript aims to summarize the current state of EC molecular characterizations, including germline alterations at the basis of hereditary EC predisposition, to discuss their clinical utility as prognostic and predictive markers.

RETRACTED: Cost-effectiveness of chemotherapy and dostarlimab for advanced or recurrent endometrial cancer

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been retracted at the request of the Authors. The authors have independently identified an error in the formula that was utilized to calculate the Quality Adjusted Life Years which invalidates the data and the conclusion of the paper. The authors have contacted the journal requesting to retract the article. Apologies are offered to the readers of the journal for any confusion or inconvenience that may have resulted from the publication of this article.

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.

Post-surgical ctDNA-based molecular residual disease detection in patients with stage I uterine malignancies

INTRODUCTION

Among uterine malignancies, endometrial cancer (EC) is the most common cancer of the female reproductive tract. Traditionally, risk stratification in EC is determined by standard clinicopathological risk factors. Although circulating tumor DNA (ctDNA) has emerged as a prognostic biomarker in various malignancies, its clinical validity in EC remains to be established.

METHODS

In this analysis of real-world data, 267 plasma samples from 101 patients with stage I EC were analyzed using a tumor-informed ctDNA assay (Signatera™ bespoke mPCR-NGS). Patients were followed post-surgically and monitored with ctDNA testing for a median of 6.8 months (range: 0.37-19.1).

RESULTS

Patients who tested ctDNA-positive at both their first time point and longitudinally experienced inferior recurrence-free survival (RFS) (HR = 6.2; p = 0.0006 and HR = 15.5; p < 0.0001, respectively), and showed a recurrence rate of 58% and 52%, vs. 6% and 0%, respectively for the ctDNA-negative patients. Most ctDNA-positive patients had high-risk histologies or sarcoma, versus low-risk and high-intermediate risk (H-IR) EC. Furthermore, patients with high-risk histologies who were ctDNA-positive showed shorter RFS compared to those who tested negative (HR = 9.5; p = 0.007), and those who tested positive in the low/H-IR cohort (HR = 0.25; p = 0.04). Post-surgically, detectable ctDNA was highly prognostic of clinical outcome and remained the only significant risk factor for recurrence when adjusted for clinicopathological risk factors, such as histologic risk group, mismatch repair (MMR), and p53 status.

CONCLUSION

Incorporating ctDNA monitoring along with traditional known risk factors may aid in identifying patients with stage I EC who are at highest risk of recurrence, and possibly aid in treatment stratification.

Characterization of mismatch-repair/microsatellite instability-discordant endometrial cancers

BACKGROUND

Mismatch-repair (MMR)/microsatellite instability (MSI) status has therapeutic implications in endometrial cancer (EC). The authors evaluated the concordance of testing and factors contributing to MMR expression heterogeneity.

METHODS

Six hundred sixty-six ECs were characterized using immunohistochemistry (IHC), MSI testing, and mut-L homolog 1 (MLH1) methylation. Select samples underwent whole-transcriptome analysis and next-generation sequencing. MMR expression of metastatic/recurrent sites was evaluated.

RESULTS

MSI testing identified 27.3% of cases as MSI-high (n = 182), MMR IHC identified 25.1% cases as MMR-deficient (n = 167), and 3.8% of cases (n = 25) demonstrated discordant results. A review of IHC staining explained discordant results in 18 cases, revealing subclonal loss of MLH1/Pms 1 homolog 2 (PMS2) (n = 10) and heterogeneous MMR IHC (mut-S homolog 6 [MSH6], n = 7; MLH1/PMS2, n = 1). MSH6-associated Lynch syndrome was diagnosed in three of six cases with heterogeneous expression. Subclonal or heterogeneous cases had a 38.9% recurrence rate (compared with 16.7% in complete MMR-deficient cases and 9% in MMR-proficient cases) and had abnormal MMR IHC results in all metastatic recurrent sites (n = 7). Tumors with subclonal MLH1/PMS2 demonstrated 74 differentially expressed genes (determined using digital spatial transcriptomics) when stratified by MLH1 expression, including many associated with epithelial-mesenchymal transition.

CONCLUSIONS

Subclonal/heterogeneous MMR IHC cases showed epigenetic loss in 66.7%, germline mutations in 16.7%, and somatic mutations in 16.7%. MMR IHC reported as intact/deficient missed 21% of cases of Lynch syndrome. EC with subclonal/heterogeneous MMR expression demonstrated a high recurrence rate, and metastatic/recurrent sites were MMR-deficient. Transcriptional analysis indicated an increased risk for migration/metastasis, suggesting that clonal MMR deficiency may be a driver for tumor aggressiveness. Reporting MMR IHC only as intact/deficient, without reporting subclonal and heterogeneous staining, misses opportunities for biomarker-directed therapy.

PLAIN LANGUAGE SUMMARY

Endometrial cancer is the most common gynecologic cancer, and 20%-40% of tumors have a defect in DNA proofreading known as mismatch-repair (MMR) deficiency. These results can be used to guide therapy. Tests for this defect can yield differing results, revealing heterogeneous (mixed) proofreading capabilities. Tumors with discordant testing results and mixed MMR findings can have germline or somatic defects in MMR genes. Cells with deficient DNA proofreading in tumors with mixed MMR findings have DNA expression profiles linked to more aggressive characteristics and cancer spread. These MMR-deficient cells may drive tumor behavior and the risk of spreading cancer.

Molecular subtypes of endometrial cancer: Implications for adjuvant treatment strategies

BACKGROUND

When determining adjuvant treatment for endometrial cancer, the decision typically relies on factors such as cancer stage, histologic grade, subtype, and a few histopathologic markers. The Cancer Genome Atlas revealed molecular subtyping of endometrial cancer, which can provide more accurate prognostic information and guide personalized treatment plans.

OBJECTIVE

To summarize the expression and molecular basis of the main biomarkers of endometrial cancer.

SEARCH STRATEGY

PubMed was searched from January 2000 to March 2023.

SELECTION CRITERIA

Studies evaluating molecular subtypes of endometrial cancer and implications for adjuvant treatment strategies.

DATA COLLECTION AND ANALYSIS

Three authors independently performed a comprehensive literature search, collected and extracted data, and assessed the methodological quality of the included studies.

MAIN RESULTS

We summarized the molecular subtyping of endometrial cancer, including mismatch repair deficient, high microsatellite instability, polymerase epsilon (POLE) exonuclease domain mutated, TP53 gene mutation, and non-specific molecular spectrum. We also summarized planned and ongoing clinical trials and common therapy methods in endometrial cancer. POLE mutated endometrial cancer consistently exhibits favorable patient outcomes, regardless of adjuvant therapy. Genomic similarities between p53 abnormality endometrial cancer and high-grade serous ovarian cancer suggested possible overlapping treatment strategies. High levels of immune checkpoint molecules, such as programmed cell death 1 and programmed cell death 1 ligand 1 can counterbalance mismatch repair deficient endometrial cancer immune phenotype. Hormonal treatment is an appealing option for high-risk non-specific molecular spectrum endometrial cancers, which are typically endometrioid and hormone receptor positive. Combining clinical and pathologic characteristics to guide treatment decisions for patients, including concurrent radiochemotherapy, chemotherapy, inhibitor therapy, endocrine therapy, and immunotherapy, might improve the management of endometrial cancer and provide more effective treatment options for patients.

CONCLUSIONS

We have characterized the molecular subtypes of endometrial cancer and discuss their value in terms of a patient-tailored therapy in order to prevent significant under- or overtreatment.

A comprehensive analysis of immunotherapy in advanced endometrial cancer (Review)

The morbidity and mortality rates of endometrial cancer (EC) are increasing yearly. Early-stage EC can be effectively treated through surgery or surgery combined with radiotherapy and chemotherapy. Advanced and recurrent EC is treated with chemotherapy and comprehensive treatment; however, the prognosis for patients at this disease stage is poor. Consequently, novel and effective treatment strategies are urgently required for these patients. Breakthrough progress has been made with the use of immunosuppressants in the treatment of EC, which have been included in treatment guidelines. In the present review, the etiology and classification of EC was outlined and the relevant scientific basis for the application of immunosuppressants in advanced and recurrent EC was discussed. The relevant published and ongoing clinical trials are also summarized. As such, the present review aimed to provide a scientific summary of immunotherapy of EC.

Attack of the clones: Unveiling subclonal/heterogenous mismatch repair/microsatellite instability status in endometrial cancer

Any time there are two or more tests for a given analyte, there will be some degree of disagreement between them. This editorial contextualizes the recent findings by Riedinger and colleagues regarding discordant mismatch repair and microsatellite instability testing in endometrial cancer.

Radiomics analysis of multiparametric MRI for preoperative prediction of microsatellite instability status in endometrial cancer: a dual-center study

Objective

To develop and validate a multiparametric MRI-based radiomics model for prediction of microsatellite instability (MSI) status in patients with endometrial cancer (EC).

Methods

A total of 225 patients from Center I including 158 in the training cohort and 67 in the internal testing cohort, and 132 patients from Center II were included as an external validation cohort. All the patients were pathologically confirmed EC who underwent pelvic MRI before treatment. The MSI status was confirmed by immunohistochemistry (IHC) staining. A total of 4245 features were extracted from T2-weighted imaging (T2WI), contrast enhanced T1-weighted imaging (CE-T1WI) and apparent diffusion coefficient (ADC) maps for each patient. Four feature selection steps were used, and then five machine learning models, including Logistic Regression (LR), k-Nearest Neighbors (KNN), Naive Bayes (NB), Support Vector Machine (SVM), and Random Forest (RF), were built for MSI status prediction in the training cohort. Receiver operating characteristics (ROC) curve and decision curve analysis (DCA) were used to evaluate the performance of these models.

Results

The SVM model showed the best performance with an AUC of 0.905 (95%CI, 0.848-0.961) in the training cohort, and was subsequently validated in the internal testing cohort and external validation cohort, with the corresponding AUCs of 0.875 (95%CI, 0.762-0.988) and 0.862 (95%CI, 0.781-0.942), respectively. The DCA curve demonstrated favorable clinical utility.

Conclusion

We developed and validated a multiparametric MRI-based radiomics model with gratifying performance in predicting MSI status, and could potentially be used to facilitate the decision-making on clinical treatment options in patients with EC.

Association of mismatch repair deficiency in endometrial cancer with 18F-FDG PET/CT and clinicopathological features and their prognostic value

PURPOSE

Identification of the mismatch repair (MMR) deficiency in endometrial cancer (EC) may aid in the screening of patients who may benefit from immunotherapy. Our goal was to investigate the relationship between MMR status and 18F-FDG PET/CT metabolic parameters and clinicopathological features in patients with EC, as well as to explore their prognostic value.

METHODS

This retrospective study included 106 EC patients who were classified as MMR deficient (dMMR) or MMR proficient (pMMR) group based on MMR protein expression status evaluated by immunohistochemistry. Clinicopathological characteristics and PET metabolic parameters were compared between the dMMR and pMMR groups, and their relationships with MMR status and prognosis were evaluated.

RESULTS

Of 106 EC patients, 30 patients (28.1%) had dMMR, while 76 (71.7%) had pMMR. Compared with the pMMR group, the dMMR group showed a lower prevalence of overweight (BMI ≥ 25) (17.2% vs. 43.9%, P = 0.019) and more lymph vascular space invasion (43.3% vs. 21.1%, P = 0.029). Although no relationship between glucometabolism parameters and MMR status was observed in all enrolled patients, higher SUVmax was observed in the endometrioid type of EC with MMR deficiency (P = 0.047). Additionally, SUVmax related to MMR status was found in EC patients with advanced FIGO stage (P = 0.026) or deep myometrial invasion (P = 0.026). Multivariate Cox regression analysis revealed that lymph node metastasis was independently predictive of PFS, while advanced FIGO stage was an independent predictor of OS. No significant association between MMR status and prognosis was found in EC.

CONCLUSION

Higher SUVmax was associated with MMR deficiency in EC patients with endometrioid type, advanced stage, or deep myometrial invasion, which may be useful for predicting the MMR status and thus aiding in determination of immunotherapy for patients with EC.

Colorectal Cancer Immunotherapy: State of the Art and Future Directions

Cancer immunotherapy has become an indispensable mode of treatment for a multitude of solid tumor cancers. Colorectal cancer (CRC) has been one of the many cancer types to benefit from immunotherapy, especially in advanced disease where standard treatment fails to prevent recurrence or results in poor survival. The efficacy of immunotherapy in CRC has not been without challenge, as early clinical trials observed dismal responses in unselected CRC patients treated with checkpoint inhibitors. Many studies and clinical trials have since refined immunotherapies available for CRC, solidifying immunotherapy as a powerful asset for CRC treatment. This review article examines CRC immunotherapies, from their foundation, through emerging avenues for improvement, to future directions.

Pathologic, immunologic, and clinical analysis of the microsatellite instability phenotype in endometrial carcinoma

The objective of this study was to determine if quantifying the microsatellite instability (MSI) phenotype could serve as a biomarker for clinical and immunologic features of deficient mismatch repair (dMMR) endometrial cancer (EC). Patients with EC undergoing hysterectomy whose tumors demonstrated dMMR were included. Immunohistochemistry (IHC) of mismatch repair proteins and polymerase chain reaction analysis of NR27, BAT25, BAT26, NR24, and NR21 microsatellite loci were performed on each case. The MSI phenotype was quantified by subtracting the number of nucleotides of each microsatellite in tumor tissue from the corresponding microsatellite in paired normal tissue and summing the absolute differences. This was termed marker sum (MS) and is a novel quantification. Tumor-infiltrating lymphocytes (TILs) were identified by IHC for CD3, CD4, and CD8 and quantified with digital image analysis. Tumor infiltration of lymphocytes and clinical characteristics were stratified by MS. Four hundred fifty-nine consecutive patients with dMMR EC were analyzed. MS ranged from 1 to 32. Post hoc, 2 cohorts were defined using receiver operating characteristic curves (MS less than 13 and MS greater than 12). With the exception of tumor grade, all clinical and pathologic features, all tumor characteristics, and the numbers of TILs were similar between cohorts. The MSI phenotype is highly variable in dMMR EC, and no correlation between the immune profile and the severity of the MSI phenotype was observed.

Clinicopathologic significance of mismatch repair protein expression in endometrioid endometrial cancer

OBJECTIVE

To evaluate the association between mismatch repair (MMR) protein expression and clinico-pathologic outcomes in patients with endometrioid endometrial cancer (EC).

MATERIALS AND METHODS

A retrospective review of the clinico-pathologic outcomes was performed on patients who were diagnosed with EC and had results of MMR protein immunohistochemistry. MMR-deficient (MMR-d) was defined as absence of expression in any of the 4 MMR proteins (MLH1, MSH2, MSH6, and PMS2). Demographics, pathologic variables, and survival outcomes were compared according to the MMR status.

RESULTS

A total of 193 EC patients with available MMR expression data were included, of whom 163 patients had endometrioid type EC. Overall, 44 patients (27.0%) were classified as MMR-d. Compared with MMR-proficient (MMR-p) group, MMR-d group was associated with more frequent lymphovascular space invasion (LVSI, p = 0.001). MMR-d was also related with higher risk of lymph node (LN) metastasis in endometrioid type EC (p = 0.008), especially para-aortic LN metastasis. During the median follow-up period of 19.1 months (1-44.5), MMR-d group, especially MLH1/PMS2 subgroup, showed a tendency of reduced PFS (p = 0.036 and p = 0.008, respectively). On Cox regression analysis, however, LN metastasis remained as the only independent risk factor for PFS (p = 0.004) in endometrioid EC, and MLH1/PMS2 loss showed a marginally significant association (p = 0.054).

CONCLUSION

Our findings of the associations between MMR deficiency and poor prognostic factors, such as LVSI and LN metastasis, may suggest the prognostic value of MMR status in EC and need further prospective validation studies.

Adoption of Universal Testing in Endometrial Cancers for Microsatellite Instability Using Next-Generation Sequencing

PURPOSE

To assess implementation of a next-generation sequencing (NGS) assay to detect microsatellite instability (MSI) as a screen for Lynch syndrome (LS) in endometrial cancer (EC), while determining and comparing characteristics of the four molecular subtypes.

METHODS

A retrospective review was performed of 408 total patients with newly diagnosed EC: 140 patients who underwent universal screening with NGS and 268 patients who underwent screening via mismatch repair immunohistochemistry (MMR IHC) as part of a historical screening paradigm. In the NGS cohort, incidental POLE and TP53 mutations along with MSI were identified and used to characterize EC into molecular subtypes: POLE-ultramutated, MSI high (MSI-H), TP53-mutated, and no specific molecular profile (NSMP). In historical cohorts, age- and/or family history-directed screening was performed with MMR IHC. Statistical analysis was performed using a t-test for continuous variables and chi-square or Fisher's exact test for categorical variables.

RESULTS

In the NGS cohort, 38 subjects (27%) had MSI-H EC, 100 (71%) had microsatellite stable EC, and two (1%) had an indeterminate result. LS was diagnosed in two subjects (1%), and all but five patients completed genetic screening (96%). Molecular subtypes were ascertained: eight had POLE-ultramutated EC, 28 had TP53-mutated EC (20%), and 66 (47%) had NSMP. MSI-H and TP53-mutated EC had worse prognostic features compared with NSMP EC. Comparison with historical cohorts demonstrated a significant increase in follow-up testing after an initial positive genetic screen in the MSI NGS cohort (56% v 89%; P = .001).

CONCLUSION

MSI by NGS allowed for simultaneous screening for LS and categorization of EC into molecular subtypes with prognostic and therapeutic implications.

Lynch syndrome-associated endometrial cancer patient with a rare novel germline likely pathogenic variant of MSH2 gene: A case report

The Lynch syndrome (LS) is an autosomal dominant condition usually characterized by germline pathogenic variants in DNA mismatch repair (MMR) genes. Despite the guidelines now available, determining the pathogenicity of rare variants remains challenging, as the clinical significance of a genetic variant could be uncertain, but it may represent a disease-associated variation in the aforementioned genes. In this case report we will describe the case of a 47 years-old female affected by endometrial cancer (EC) with an extremely rare germline heterozygous variant in the MSH2 gene (c.562G > T p. (Glu188Ter), exon 3) that is likely pathogenic, and a family history consistent with LS.

Nectin-4 as a Predictive Marker for Poor Prognosis of Endometrial Cancer with Mismatch Repair Impairment

The adhesion molecule Nectin-4 is a new potential therapeutic target for different types of cancer; however, little is known about its diagnosis significance in endometrial cancer (EC). We found that Nectin-4 expression was significantly higher in EC tissues than in nonadjacent normal tissue. The area under the receiver operating characteristic curve value of 0.922 indicated good diagnostic accuracy for Nectin-4 expression in EC. Furthermore, Nectin-4 expression was associated with DNA mismatch repair (MMR) protein deficiency. Notably, the high Nectin-4 expression group of patients with MSH2/6-deficient EC had shorter progression-free survival than that of the low Nectin-4 expression group. The number of lymphovascular space invasion-positive patients in groups with MMR deficiency and high Nectin-4 expression was also increased compared with that in the low Nectin-4 expression group. Bioinformatics analysis revealed that alteration in Nectin-4 and MMR genes is associated with Nectin-4 expression in EC. To the best of our knowledge, this is the first study to show that Nectin-4 expression may be a potential biomarker for EC diagnosis and that high Nectin-4 expression in MMR-deficient patients with EC can predict short progression-free survival, thus providing clues to identify patients for adjuvant therapy.

Tyrosine kinase inhibitor toxicities: A society of gynecologic oncology review and recommendations

OBJECTIVE

Oral tyrosine kinase inhibitors (TKIs) have new indications for treatment in gynecologic malignancies. These targeted drugs have both unique and overlapping toxicities, which require careful attention and management. New combination therapies with immune-oncology agents have demonstrated promise in endometrial cancer. This review examines common adverse events associated with TKIs and provides readers with an evidence-based review on current uses and strategies for the management of these medications.

METHODS

A comprehensive review of the medical literature on TKI use in gynecologic cancer was undertaken by a committee approach. Details of each drug, its molecular target, and relevant data on both clinical efficacy and side effects were compiled and organized for clinical use. Information on drug-related secondary effects and management strategies for specific toxicities, including dose reduction and concomitant medications, were gathered.

RESULTS

TKIs can potentially offer improved response rates and durable responses for a group of patients who were previously without an effective standard second-line therapy. The combination of lenvatinib and pembrolizumab represents a more targeted approach to the drivers of endometrial cancer; however, there remains significant drug-related toxicity, and thus dose reduction and dose delay are frequently required. Toxicity management requires frequent check-ins and management strategies to help patients find the highest tolerable dose. TKIs are expensive and patient financial toxicity is as critical a measure of a drug's utility as any drug side effect. Many of these drugs have patient assistance programs, which should be fully utilized to minimize cost.

CONCLUSIONS

Future studies are needed to expand the role of TKIs into new molecularly driven groups. Attention to cost, durability of response, and long-term toxicity management is needed to ensure all eligible patients have access to treatment.

Promising Therapeutic Impact of Immune Checkpoint Inhibitors in Type II Endometrial Cancer Patients with Deficient Mismatch Repair Status

Type II endometrial cancer (EC) is responsible for most endometrial cancer-related deaths due to its aggressive nature, late-stage detection, and high tolerance to standard therapies. Thus, novel treatment strategies for type II EC are imperative. For patients with mismatch repair-deficient (dMMR) tumors, immunotherapy with immune checkpoint inhibitors represents a promising therapeutic strategy. However, the prevalence of dMMR tumors in type II EC patients remains unclear. In this study, using immunohistochemistry, we evaluated the expression of mismatch repair (MMR) proteins, tumor-infiltrating lymphocytes (CD8+), and immune checkpoint molecules (PD-L1) in 60 patients with type II EC (16, 5, 17, and 22 were endometrioid G3, serous, de-differentiated, and carcinosarcoma cases, respectively) to investigate the therapeutic effect of immune checkpoint inhibitors. Approximately 24 cases (40%) had a loss of MMR protein expression. The positivity rate of CD8+ (p = 0.0072) and PD-L1 (p = 0.0061) expression was significantly associated with the dMMR group. These results suggest immune checkpoint inhibitors (anti-PD-L1/PD-1 antibodies) could effectively treat type II EC with dMMR. The presence of dMMR might be a biomarker for a positive response to PD-1/PD-L1 immunotherapy in type II EC.

Back to the future: The impact of oestrogen receptor profile in the era of molecular endometrial cancer classification

PURPOSE

The aim of this study is to evaluate the impact of the oestrogen receptor (ER) profile on oncologic outcomes in the new endometrial cancer (EC) risk classification.

METHODS

Immunohistochemistry (IHC) analyses were performed in a retrospectively reviewed large series of ECs to assess the presence/absence of oestrogen receptors (ER0\1+ or ER2+\3+) and other molecular factors (i.e. p53 mutation, p53mut; and mismatch repair mutational status, MMRd (mismatch repair deficient) versus MMRp (mismatch repair proficient)), histopathologic and clinical outcomes. ER status was correlated with molecular, histologic, clinical and prognostic data.

RESULTS

891 EC patients were included in the study (211 ER0\1+ and 680 ER2+\3+). The ER0\1+ phenotype was associated with an unfavourable clinicopathological profile (i.e. grading, histotype, lymphovascular space invasion (LVSI), stages, etc.). Simple regression showed that risk class, p53mut, and ER0/1+ impacted on both disease-free survival (DFS) and overall survival (OS) (p < 0.05). In the ER0/1+ population, p53mut no longer influenced DFS and OS (p > 0.05). In multiple regression, age, high and advanced/metastatic risk classes influenced survival outcomes (p < 0.05), but lost significance in the ER0/1+ population (p > 0.05). ER-positivity retained a remarkable prognostic impact even after stratification of the population according to the European Society of Gynaecological Oncology, the European Society for Radiotherapy and Oncology, and the European Society of Pathology (ESGO/ESTRO/ESP) 2021 risk classes and molecular classification. ER0/1+ intermediate, high-intermediate, high and advanced risk versus ER2+/3+ intermediate, high-intermediate, high and advanced risk classes showed statistically different OS and DFS (p< 0.001). ER0/1+ status was associated with a worse prognosis when associated with MMRp, MMRd and p53mut compared to the same molecular classes associated with ER2+/3 (p < 0.001).

CONCLUSIONS

We demonstrated that ER status has a significant impact on oncologic outcomes, regardless of risk class and p53/MMR status. Based on our results, we recommend the inclusion of ER assessment in featured EC risk classification system.

Immunotherapy in endometrial cancer

The Cancer Genome Atlas (TCGA) endometrial cancer data expanded our knowledge about the role of different immunotherapeutic approaches based on molecular subtypes. Immune checkpoint inhibitors demonstrated distinct antitumor activities as monotherapy or in combination. In microsatellite unstable (microsatellite instability-high) endometrial cancer, immunotherapy with immune checkpoint inhibitors showed promising single agent activity in recurrent settings. Different strategies are needed to enhance the response or reverse resistance to immune checkpoint inhibitors, or both, in microsatellite instability-high endometrial cancer. On the other hand, single immune checkpoint inhibitors showed underwhelming efficacy in microsatellite stable endometrial cancer but this was significantly improved using a combination approach. Furthermore, studies are also needed to improve response along with ensuring safety and tolerability in microsatellite stable endometrial cancer. This review summarizes the current indications of immunotherapy for the treatment of advanced and recurrent endometrial cancer. We also outline potential future strategies for an immunotherapy based combination approach in endometrial cancer to combat resistance or enhance response to immune checkpoint inhibitors, or both.

Microsatellite instability as a marker of prognosis: a systematic review and meta-analysis of endometrioid endometrial cancer survival data

INTRODUCTION

To investigate whether microsatellite instability (MSI) is an important prognostic biomarker for endometrioid endometrial cancer (EEC).

METHODS

The PubMed, EMBASE, and the Cochrane Cooperative Library databases were searched from inception to July 2021. Overall survival, disease-free survival, progression-free survival, EEC-specific survival, recurrence-free survival, and the recurrence rate were pooled to analyze the correlation between MSI and EEC. In addition, Egger's regression analysis and Begg's test were used to detect publication bias.

RESULTS

17 studies met the inclusion criteria and were included in our meta-analysis with a sample size of 4723, and the included patients with endometrioid cancer (EC) all were EEC. The pooled hazard ratios (HR) in patients with EEC showed that MSI was significantly associated with shorter overall survival [HR = 1.37, 95% confidence interval (CI) (1.00-1.86), p = 0.048, I2 = 60.6%], shorter disease-free survival [HR = 1.99, 95% CI (1.31-3.01), p = 0.000, I2 = 67.2%], shorter EEC-specific survival [HR = 2.07, 95% CI (1.35-3.18), p = 0.001, I2 = 31.6%] and a higher recurrence rate [Odds ratios (OR) = 2.72, 95% CI (1.56-4.76), p = 0.000, I2 = 0.0%]. In the early-stage EEC subgroup, MSI was significantly associated with shorter overall survival [HR = 1.47, 95% CI (1.11-1.95), p = 0.07], shorter disease-free survival [HR = 4.17, 95% CI (2.37-7.41), p = 0.000], and shorter progression-free survival [HR = 2.41, 95% CI (1.05-5.54), p = 0.039]. No significant heterogeneity was observed in overall survival (I2 = 20.9%), disease-free survival (I2 = 0.0%), or progression-free survival (I2 = 0.0%) in patients with early-stage EEC. Meanwhile, publication bias was not observed, and the p-value for Egger's test of overall survival, disease-free survival, and EEC-specific survival were p = 0.131, p = 0.068, and p = 0.987, respectively.

CONCLUSION

MSI is likely an important biomarker for poor prognosis in patients with EEC, and this correlation is even more certain in patients with early-stage EEC.

Can mismatch repair status be added to sentinel lymph node mapping algorithm in endometrioid endometrial cancer?

OBJECTIVE

To evaluate the relation between mismatch repair (MMR) status and the risk of lymph node metastasis in endometrial cancer, and whether this additional data can be incorporated to current SLN (sentinel lymph node) algorithm.

METHODS

We included a series of 332 women that underwent SLN mapping ± systematic lymphadenectomy from January 2013 to December 2021. Protein expressions of MLH1, MSH2, MSH6, PMS2 were examined by immuno-histochemistry and considered MMRd (deficient) when at least one protein was not expressed.

RESULTS

MMRd was noted in 20.8% of cases and correlated to grade 3 (p = 0.018) and presence of lymphovascular space invasion (p = 0.032). Moreover, MMRd was an independent risk factor for lymph node metastasis (OR 2.76, 95% CI 1.36-5.62). Notably, 21.7% (15/69) cases with MMRd had lymph node metastasis compared to 9.5% (25/263) of cases with MMRp (proficient) (p = 0.005). The overall and bilateral SLN detection rates were 91.9% and 75.9%, respectively. Of the 80 (24%) cases of non-bilateral SLN detection, 66.2% had low-grade tumors (G1/G2) and myometrial invasion <50%. Considering MMR status an independent prognostic factor for lymph node metastasis, a systematic lymphadenectomy (side specific or bilateral) would forgo in 53.7% (43/80) of cases with non-bilateral detection, representing 13% (43/332) of all endometroid tumors.

CONCLUSION

MMR status was independently related to lymph node metastasis in endometrioid EC. Moreover, MMR status may help to select patients that can forgo systematic lymphadenectomy in case of undetected SLN.

Epigenetic MMR defect identifies a risk group not accounted for through traditional risk stratification algorithms in endometrial cancer

Purpose

We sought to evaluate the contribution of mismatch repair (MMR) status to traditional risk stratification algorithms used to predict nodal involvement and recurrence in a large single-institution cohort.

Methods

Endometrioid endometrial cancer (EC) cases from 2014-2020 were evaluated. MMR immunohistochemistry (IHC) was performed universally. Uterine factors assessed in the Mayo criteria were used to retrospectively classify patients as low or high risk for lymphatic spread. Patients were classified according to risk for recurrence using GOG 99 and PORTEC criteria. Associations were evaluated using chi-square and t-tests and contributing factors assessed using logistic regression models.

Results

1,514 endometrioid EC were evaluated; 392 (25.9%) were MMR (MMR) deficient of which 80.4% of MMR defects were associated with epigenetic silencing of MLH1. Epigenetic MMR defects were significantly more likely to be high risk for lymph node (LN) metastasis based on Mayo criteria (74.9% vs 60.6%, p=<0.001) and with the presence of LN metastasis (20.3 vs 10.5%, p=0.003) compared to MMR proficient tumors. Tumors with epigenetic MMR defects were significantly more likely to be classified as high or high intermediate risk using GOG99 and PORTEC criteria. Furthermore, cases with epigenetic MMR defects classified as low or low intermediate risk were significantly more likely to recur (GOG99 p=0.013; PORTEC p=0.008) and independently associated with worse disease-free survival (DFS). MMR status was found to be independently associated with worse DFS (HR 1.90; 95% CI 1.34-2.70; p=0.003) but not overall survival.

Conclusion

While MMR deficient EC has been associated with poor prognostic features in prior reports; we demonstrate that only epigenetic MMR defects have poorer outcomes. Epigenetic MMR defect were independently associated with lymph node metastasis after controlling for risk criteria. Epigenetic MMR deficiency was found to be an independent predictor of recurrence beyond the factors considered in traditional risk stratification algorithms. Traditional uterine-based risk stratification algorithms may not fully reflect the risk for recurrence in MMR deficient tumors. Consideration should be given to implementing MMR status and MLH1 hypermethylation alongside traditional risk stratification algorithms. Performing MMR IHC on preoperative pathologic specimens may aid in risk stratification and patient counseling.

Exploring biomarkers and prognostic factors in uterine carcinosarcoma: An insight into L1CAM, CDX2, p53, and MSI status

BACKGROUND

Uterine Carcinosarcomas (UCS) are a rare type of cancer composed of an admixture of high-grade carcinomatous and sarcomatous elements. Clinicopathological prognostic factors in UCS are well established, but studies that approach the impact of biomarkers in this unusual disease are scarce. The study objective was to evaluate the prevalence and prognostic impact of a panel of prominent biomarkers in uterine carcinosarcoma (UCS) using an immunohistochemical characterization with four biomarkers.

METHODS AND FINDINGS

The internal database of a single Brazilian institution was carefully explored to select women diagnosed with UCS who were submitted to surgery and postoperative chemotherapy with carboplatin and paclitaxel between January 2012 and December 2017. Tissue microarrays containing UCS samples were evaluated by immunohistochemistry for L1CAM, CDX2, p53 and microsatellite instability markers. A total of 57 cases were included. The mean age was 65.3 years (standard deviation, SD 7.0). L1CAM was negative (score 0, no staining) in 27 (47.4%) patients. Of L1CAM-positive, 10 (17.5%) showed weak (score 1, <10%), 6 (10.5%) showed moderate (score 2, between 10-50%), and 14 (24.6%) showed strong L1CAM staining (score 3, ≧50%). dMMR occurred in 3 (5.3%) cases. The p53 was aberrantly expressed in 15 (26.3%) tumors. CDX2 was positive in 3 (5.3%) patients. The three-year progression-free survival (PFS) rate in the general population of the study was 21.2% (95% CI: 11.7-38.1) and the three-year overall survival (OS) rate was 29.4% (95% CI: 18.1-47.6). By multivariate analysis, the presence of metastases and CDX2-positive were significantly associated with poorer PFS (p < 0.001 and p = 0.002, respectively) and OS (p < 0.001 and p = 0.009, respectively).

CONCLUSION

The strong influence of CDX2 on prognosis requires further investigation. Biological or molecular variability may have impaired the assessment of the impact of the other markers on survival.

Magnetic resonance-based radiomics nomogram for predicting microsatellite instability status in endometrial cancer

Background

Microsatellite instability (MSI) status is an important indicator for screening patients with endometrial cancer (EC) who have potential Lynch syndrome (LS) and may benefit from immunotherapy. This study aimed to develop a magnetic resonance imaging (MRI)-based radiomics nomogram for the prediction of MSI status in EC.

Methods

A total of 296 patients with histopathologically diagnosed EC were enrolled, and their MSI status was determined using immunohistochemical (IHC) analysis. Patients were randomly divided into the training cohort (n=236) and the validation cohort (n=60) at a ratio of 8:2. To predict the MSI status in EC, the tumor radiomics features were extracted from T2-weighted images and contrast-enhanced T1-weighted images, which in turn were selected using one-way analysis of variance (ANOVA) and the least absolute shrinkage and selection operator (LASSO) algorithm to build the radiomics signature (radiomics score; radscore) model. Five clinicopathologic characteristics were used to construct a clinicopathologic model. Finally, the nomogram model combining radscore and clinicopathologic characteristics was constructed. The performance of the three models was evaluated using receiver operating characteristic (ROC), calibration, and decision curve analyses (DCA).

Results

Totals of 21 radiomics features and five clinicopathologic characteristics were selected to develop the radscore and clinicopathological models. The radscore and clinicopathologic models achieved an area under the curve (AUC) of 0.752 and 0.600, respectively, in the training cohort; and of 0.723 and 0.615, respectively, in the validation cohort. The radiomics nomogram model showed improved discrimination efficiency compared with the radscore and clinicopathologic models, with an AUC of 0.773 and 0.740 in the training and validation cohorts, respectively. The calibration curve analysis and DCA showed favorable calibration and clinical utility of the nomogram model.

Conclusions

The nomogram incorporating MRI-based radiomics features and clinicopathologic characteristics could be a potential tool for the prediction of MSI status in EC.

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.

Microsatellite Instability-High Endometrial Cancers with MLH1 Promoter Hypermethylation Have Distinct Molecular and Clinical Profiles

PURPOSE

Microsatellite instability-high (MSI-H) endometrial carcinomas are underpinned by distinct mechanisms of DNA mismatch repair deficiency (MMR-D). We sought to characterize the clinical and genetic features of MSI-H endometrial cancers harboring germline or somatic mutations in MMR genes or MLH1 promoter hypermethylation (MLH1ph).

EXPERIMENTAL DESIGN

Of > 1,100 patients with endometrial cancer that underwent clinical tumor-normal sequencing, 184 had MSI-H endometrial cancers due to somatic MMR mutations or MLH1ph, or harbored pathogenic germline MMR mutations. Clinicopathologic features, mutational landscape, and tumor-infiltrating lymphocyte (TIL) scores were compared among MMR-D groups using nonparametric tests. Log-rank tests were used for categorical associations; Kaplan-Meier method and Wald test based on Cox proportional hazards models were employed for continuous variables and survival analyses.

RESULTS

Compared with patients with germline (n = 25) and somatic (n = 39) mutations, patients with MLH1ph endometrial cancers (n = 120) were older (P < 0.001), more obese (P = 0.001) and had more advanced disease at diagnosis (P = 0.025). MLH1ph endometrial cancers were enriched for JAK1 somatic mutations as opposed to germline MMR-D endometrial cancers which showed enrichment for pathogenic ERBB2 mutations. MLH1ph endometrial cancers exhibited lower tumor mutational burden and TIL scores compared with endometrial cancers harboring germline or somatic MMR mutations (P < 0.01). MLH1ph endometrial cancer patients had shorter progression-free survival (PFS) on univariate analysis, but in multivariable models, stage at diagnosis remained the only predictor of survival. For stage I/II endometrial cancer, two-year PFS was inferior for patients with MLH1ph endometrial cancers compared with germline and somatic MMR groups (70% vs. 100%, respectively).

CONCLUSIONS

MLH1ph endometrial cancers likely constitute a distinct clinicopathologic entity compared with germline and somatic MMR-D ECs with potential treatment implications.

Association of immunohistochemical profiles with histotypes in endometrial carcinomas

OBJECTIVE

Although a large number of endometrial cancer patients are cured with surgery alone, there are significant numbers of patients with more aggressive variants of endometrial carcinoma for whom the prognosis remains poor. We investigated the effects of prevalence, histotypes, and immunohistochemical profiles on prognostic value in a hospital-based population.

MATERIALS AND METHODS

A retrospective study of surgically resected primary endometrial carcinoma was included. Immunohistochemical stains were performed on formalin-fixed paraffin-embedded tissue microarray sections for β-Catenin, estrogen receptor (ER), progesterone receptor (PR), HER-2, MLH1, MSH2, MSH6, PMS2, and p53.

RESULTS

Loss of mismatch repair expression was detected in 25.4% of samples (29/114, mean age 57 years) of the tumors. The following loss of expression was observed in patients: MLH1/PMS2 in 16.6% of patients, MSH6 in 7.0% of patients, MLH1 in 0.9% of patients, and MSH6/PMS2/MLH1 in 0.9% of patients. Immunohistochemistry of p53 was analyzed for 111 patients. A total of 13 patients (11.7%, mean age 64 years) had p53-abnormal expression (absent, cytoplasmic or diffuse strong positive patterns), and more than half (9/13, 69.2%) had endometrioid histotype. Abnormalities in p53 were significantly associated with histotype (p = 0.001), advanced tumor stage (p = 0.038), death of disease (p = 0.002), PR percentage (p = 0.002), and HER-2 expression (p = 0.018). Immunohistochemical nuclear localization of β-Catenin was detected in 7.1% of the cohort. The combination of p53 and nuclear β-Catenin expressions was not significantly predictive of disease-free or overall survival.

CONCLUSION

The results of this study are useful for management of endometrial cancer in patients with DNA mismatch repair, abnormal p53 expression, or nuclear localization of β-Catenin.

Endometrial Carcinoma: Molecular Cytogenetics and Transcriptomic Profile

Endometrial carcinomas (ECs) are histologically classified as endometrioid and nonendometrioid tumors, with each subgroup displaying different molecular profiles and clinical outcomes. Considerable biological and clinical heterogeneity exists within this scheme, however, reflecting its imperfection. We aimed to gather additional data that might help clarify the tumors’ pathogenesis and contribute toward a more meaningful classification scheme. In total, 33 ECs were examined for the presence of chromosomal aberrations, genomic imbalances, pathogenic variants, microsatellite instability, and expression profiles at both gene and miRNA levels. Chromosome 1 was the most frequently rearranged chromosome, showing a gain of all or part of the long arm. Pathogenic variants were found for PTEN (53%), PDGFRA (37%), PIK3CA (34%), and KIT (31%). High microsatellite instability was identified in 15 ECs. Comparing tumors and controls, we identified 23 differentially expressed genes of known importance in carcinogenesis, 15 genes involved in innate and adaptative immune responses, and altered expression of 7 miRNAs. miR-32-5p was the most upregulated. Our series showed a high degree of heterogeneity. Tumors were well-separated from controls, but there was no clear-cut separation between endometrioid and nonendometrioid ECs. Whether this means that the current phenotypic classification is of little relevance or if one still has not detected which genomic parameters to enter into correlation analyses remains unknown.

Comprehensive Clinicopathologic Analysis for Mismatch Repair Protein Expression in Unselected Endometrial Carcinoma Patients With an Emphasis on the Role of MLH1 Deficiency

Screening for mismatch repair (MMR) deficiency in unselected patients with endometrial carcinoma (EC) and the clinicopathologic descriptions of ECs with MMR deficiency have been well demonstrated in Western populations, but studies on Asian populations are relatively scarce. In this study, we described the clinicopathologic features of ECs according to MMR status in unselected Taiwanese patients. We also conducted subgroup analysis of MMR-deficient (dMMR) cases according to the presence or absence of MLH1. Patients diagnosed with ECs between January 2017 and February 2020 at our institution were included. Immunohistochemistry analysis of MLH1, PMS2, MSH2, and MSH6 proteins on endometrial primary tumors and clinicopathologic variables were assessed retrospectively. A total of 231 EC patients were enrolled, of whom 50 (21.6%) had dMMR tumors. Of these 50 cases, 39 had tumors that lacked MLH1 expression and 11 were positive for MLH1. The overall dMMR group was significantly related to older age, parity, and high histologic grade compared with the MMR-proficient (pMMR) group. ECs with MLH1 deficiency were obviously associated with several poor pathologic features, including high histologic grade, lymph node metastasis, and lymphovascular space invasion. Moreover, we first reported that parity and the late age at menopause are strongly correlated with MLH1-related dMMR EC group compared with pMMR group. In conclusion, triaging EC patients into pMMR, MLH1-related dMMR and non-MLH1-related dMMR groups by immunohistochemistry analysis may help clinicians to predict disease behavior and guide further management. The strong association between parity and MLH1-related dMMR ECs warrants further investigation on the underlying mechanism.

Clinicopathologic association and prognostic impact of microcystic, elongated and fragmented pattern invasion, combined with tumor budding in endometrioid endometrial cancer

AIM

As a special invasive pattern seen in low-grade endometrial carcinoma, microcystic, elongated and fragmented (MELF) pattern is related to lymph node metastasis. Tumor budding (TB) is another histological marker in many cancers associated with tumor aggressiveness. Herein, we evaluated the impact of MELF pattern combined with TB about clinicopathological features and prognosis in endometrioid endometrial cancer (EEC). To verify the relationship between the two morphological markers and microsatellite status in EEC, the primary mismatch repair (MMR) proteins were detected by immunohistochemistry.

METHODS

One hundred and seventy-two cases of ECC diagnosed between 2011 and 2016 were reviewed with a median follow up of 47.5 months. MELF pattern and TB were examined on all H&E-stained slides. Primary MMR proteins (MLH1, MSH2, MSH6, and PMS2) were also detected.

RESULTS

Based on MELF pattern and TB, 172 patients were divided into the following four groups: MELF(-)/TB(+) (n = 41), MELF(+)/TB(-) (n = 15), MELF(+)/TB(+) (n = 20), and MELF(-)/TB(-) (n = 96). Adverse pathological features were observed in the MELF(+)/TB(+) group: 70% presented deep muscular infiltration, 65% were lymphovascular space invasion, and 25% suffered lymph node metastasis. The proportion of MMR deficient in MELF(+)/TB(-) group was the highest (66.7%). The progression-free survival (PFS) and overall survival (OS) among the four groups were significantly different. MELF(+)/TB(+) group showed the worst PFS and OS. As univariate and multivariate survival analyses revealed, the combination of MELF pattern and TB was confirmed as an independent predictor of poor prognosis.

CONCLUSIONS

Our research demonstrates that MELF pattern combined with TB, as an independent predictor of adverse outcome, is associated with adverse pathological features, which facilitates better understanding of EEC tumor behavior and more precise prognosis without additional medical expense.

Endometrial Cancer: An Update on Prognostic Pathologic Features and Clinically Relevant Biomarkers

The prognosis of endometrial cancers has historically been determined by the evaluation of histologic typing, grading, and staging. Recently, molecular classification, pioneered by the 4 prognostic categories from The Cancer Genome Atlas Research Network, has been shown to independently predict the outcome, correlate with biomarker expression, and predict response to adjuvant chemotherapy. In modern-day pathology practice, it has become necessary to integrate the time-honored prognostic pathologic features with molecular classification to optimize patient management. In this review, the significance of the molecular classification of endometrioid carcinomas, the application of practical diagnostic surrogate algorithms, and interpretation of test results will be addressed. Histologic features and theragnostic biomarkers will also be discussed in relation to the molecular subtypes of endometrial cancers.

Endometrial Cancer Following Levonorgestrel-Releasing Intrauterine System Insertion in Young Women with Atypical Hyperplasia: Two Case Reports and Literature Review

Levonorgestrel-releasing intrauterine system (LNG-IUS) insertion is the first-line treatment for atypical hyperplasia (AH) in young women who wish to retain their fertility. However, the procedure is not always effective, and may allow AH to progress to endometrioid endometrial cancer (EEC). Two young women with AH who wished to preserve their fertility developed EEC following 52-mg LNG-IUS in insertion at our institution. One was a 34-year-old woman diagnosed with endometrial cancer 2 years after LNG-IUS insertion. The second was a 30-year-old woman diagnosed 17 months after LNG-IUS insertion. Proactive molecular risk classification for endometrial cancer (ProMisE) classification revealed that the first and second patients had p53-abnormal (p53abn) EEC and mismatch repair deficient (MMR-d) EEC, respectively. MMR-d and p 53abn were frequently observed in both AH and EEC specimens. Studies suggest that MMR-d and p53abn are predictors of the occurrence adverse effects after fertility-preserving treatment for EEC. AH is a precursor of EEC. Therefore, p53 and mismatch repair (MMR) mutation may be used to identify women with AH who will not likely benefit from progestin therapy. Molecular assays in women with AH will likely be useful for identifying novel predictive biomarkers of progestin resistance and to improve the safety of conservative treatment. Combined assessment of progesterone receptor (PR) with these predictive molecular markers may improve the predictive ability.

Clinicopathologic significance of DNA mismatch repair protein status in endometrial cancer

OBJECTIVE

The prognostic implications of DNA mismatch repair protein (MMRP) have not been determined in endometrial cancer. Therefore, in this study, we aimed to evaluate the clinicopathologic characteristics of DNA MMRP deficiency in endometrial cancer.

MATERIALS AND METHODS

We examined the MMRP status of 206 patients with endometrial carcinomas, using immunohistochemistry, and analyzed their clinicopathologic factors and survival outcomes stratified by MMRP status using the Kaplan-Meier method and Cox regression analysis.

RESULTS

Forty-three cases were deficient for at least one MMRP (20.9%). Loss of MLH1 was the most common (13.1%), followed by MSH6 (7.8%). MMRP deficiency was significantly associated with lympho-vascular space invasion, deep myometrial invasion, and adjuvant treatment (P = 0.032, 0.041, and 0.047, respectively). MMRP-deficient patients had a better overall survival (OS), particularly at advanced cancer stages (III/IV) (100% vs. 73.7%, P = 0.170) or if they had received adjuvant treatment (100% vs. 86.7%, P = 0.087).

CONCLUSION

Although MMRP deficiency was associated with unfavorable prognostic risk factors in endometrial cancer, we found a trend in favor of OS in MMRP-deficient patients. More studies are needed to confirm its prognostic implication.

Utility of germline multi-gene panel testing in patients with endometrial cancer

OBJECTIVES

Patients with germline mutations in mismatch repair genes (MLH1, MSH2, MSH6, PMS2) associated with Lynch syndrome (LS) have an increased lifetime risk of endometrial cancer (EC). Multi-gene panel testing (MGPT) is a recent hereditary cancer risk tool enabling next-generation sequencing of numerous genes in parallel. We determined the prevalence of actionable cancer predisposition gene mutations identified through MGPT in an EC patient cohort.

METHODS

A single center retrospective cohort study was conducted of patients with EC who had a clinical indication for genetic testing and who underwent MGPT as part of standard of care treatment between 2012 and 2021. Pathogenic mutations were identified and actionable mutations were defined as those with clinical management implications. Additionally, the number of individuals identified with LS was compared between MGPT and tumor-based screening.

RESULTS

The study included a total of 224 patients. Thirty-three patients [14.7%, 95% confidence interval (CI) = 10.4-20.1] had actionable mutations. Twenty-one patients (9.4%, 95% CI = 5.9-14.0) had mutations in LS genes (4 MLH1, 5 MSH2, 7 MSH6, 4 PMS2, 1 Epcam-MSH2). MGPT revealed two patients with LS (9.5% of LS cases) not identified through routine tumor-based screening. Thirteen patients (5.8%, 95% CI = 3.1-9.7) had at least one actionable mutation in a non-Lynch syndrome gene (6 CHEK2, 2 BRCA2, 2 ATM, 2 APC, 1 RAD51C, 1 BRCA1).

CONCLUSIONS

Germline MGPT is both feasible and informative as it identifies LS cases not found on tumor testing as well as additional actionable mutations in patients with EC.

Rare Subtype of Endometrial Cancer: Undifferentiated/Dedifferentiated Endometrial Carcinoma, from Genetic Aspects to Clinical Practice

Endometrial cancer (EC) is one of the most common gynecologic cancers worldwide. There were 417,367 newly diagnosed cases and 97,370 deaths due to this disease worldwide in 2020. The incidence rates have increased over time, especially in countries with rapid socioeconomic transitions, and EC has been the most prevalent gynecologic malignancy in Taiwan since 2012. The new EC molecular classifications of The Cancer Genome Atlas (TCGA) Research Network include clear-cell carcinoma, serous carcinoma, and carcinosarcoma, while undifferentiated/dedifferentiated EC (UDEC) is not mentioned, and most previous clinical trials for EC have not included UDEC. UDEC is rare, has an aggressive growth pattern, tends to be diagnosed at an advanced stage, and is resistant to conventional chemotherapy. In this review, case series or case reports on the clinical features and genomic/epigenetic and expression profiles on UDEC data are summarized in order to identify potential molecular targets for current and future research.

The immunohistochemical molecular risk classification in endometrial cancer: A pragmatic and high-reproducibility method

INTRODUCTION

The aim of this study is to assess the clinical reproducibility and the potential oncological validity of the molecular information provided by the immunohistochemistry (IHC) to properly stratify the endometrial cancer patients.

METHODS

Retrospective IHC analyses were conducted in a large series of 778 pre-operative uterine-confined ECs, studying the presence/absence of MLH1, MSH2, MSH6 and PMS2 to define the mismatch repair (MMR) stable or instable phenotype; the presence of p53 mutations and other molecular features. The molecular profile was correlated with histological, clinical and prognostic data.

RESULTS

Based on IHC assessment, we defined 3 EC populations: stable MMR patients (MMRs), instable patients (MMRi) and p53 mutated patients (p53+). Our result demonstrated that the IHC stratification statistically correlated with the most relevant pathologic-clinical features: FIGO stage (p < 0.001), grading (p < 0.001), histotype (p < 0.001), presence of LVSI (p < 0.001), myometrial invasion and tumor dimension (p = 0.003 for both). These 3 IHC populations statistically reflected the EC risk class ESGO-ESMO-ESP classification 2021 (p < 0.001). These results were also confirmed in the Kaplan-Meier curves in terms of overall survival (OS) and disease-free survival (DFS) (p < 0.0001). The multivariate analyses demonstrated that absence of estrogen receptor (ER) impacted the OS (p = 0.011) and, the Age > 60 years and the ER-status the DFS (p = 0.041 and p = 0.004).

CONCLUSION

In this large series, we demonstrated that the pragmatic and systematic use of IHC may have an important role to properly stratify, in terms of histological features and clinical outcomes, the EC patients.

Lynch Syndrome-Associated Endometrial Cancer With Combined EPCAM-MSH2 Deletion: A Case Report

Background

Lynch syndrome (LS), an autosomal dominant disorder, is characterized by germline pathogenic variants in DNA mismatch repair (MMR) genes like MSH2. EPCAM deletions cause a minority (3%) of LS cases. However, there are only a few reports of LS-associated endometrial cancer (LS-EC) induced by the inactivation of the MSH2 gene due to EPCAM deletions.

Case Presentation

We present the case of a 45-years old woman diagnosed with endometrial cancer (EC). Definitive surgery revealed meso-differentiated endometrioid adenocarcinoma, stage IA without lymph-vascular space invasion. Four months later, she received radiation therapy (125I radioactive seeds implantation), and platinum-containing regimen combined chemotherapy because of vaginal stump metastasis of EC. After five years, we performed immunohistochemistry (IHC) on pelvic mass because of presacral metastatic lymph node. IHC showed the absence of MSH2 and MSH6 protein expression in the pelvic mass tissue. Peripheral blood was used for genetic testing based on her cancer diagnosis and family history of cancer in close relatives. Genetic testing revealed deletions of exon 8 and 9 in EPCAM and deletions of exon 1 and 8 in MSH2; thus, we diagnosed the presence of LS. The patient underwent interstitial brachytherapy (BT) of the presacral metastatic lymph node.

Conclusion

This case highlights that patients with LS-EC who are carriers of combined EPCAM-MSH2 deletion might experience better oncologic outcomes even with early recurrence.

The clinicopathology and survival characteristics of patients with POLE proofreading mutations in endometrial carcinoma: A systematic review and meta-analysis

Background

Endometrial carcinoma (EC) is classified into four distinct molecular subgroups. Patients with polymerase epsilon exonuclease domain mutated (POLE-EDM) tumors have the best prognosis of all. This meta-analysis consolidated the clinicopathology variations reported in the POLE-mutant subtype and survival parameters in patients with EC.

Methods

The following internet data bases were searched: PubMed, Web of science, Embase and Scimage directory. Data was extracted from eligible studies including sample size, number of positive POLE-mutant cases, EDM sequencing information, clinicopathologic, and survival data. Meta-analysis and a random-effects model produced pooled estimates of POLE prognostic parameters using 95% confidence intervals (CI), hazard ratios (HR), and odds ratios (OR).

Results

The meta-analysis included 11 cohort studies comprising 5508 EC patients (442 POLE EDM tumors). Patients with POLE mutant EC were associated with improved disease specific survival (HR = 0.408, 95% CI: 0.306 to 0.543) and progression-free survival (HR = 0.231, 95% CI: 0.117 to 0.456). POLE-mutated tumors were mostly endometrioid histology (84.480%; 95% CI: 77.237 to 90.548), although not significantly more than wild type tumors (OR = 1.386; p = 0.073). The POLE mutant tumors significantly present (p<0.001) at Federation of International of Gynecologists and Obstetricians (FIGO) lower stages I-II (OR = 2.955, p<0.001) and highest grade III (OR = 1.717, P = 0.003). The tumors are significantly associated with invasion less than half (<50%) of the myometrium (OR = 1.765, p = 0.001), but not deeply invasive EC (MI>50%, OR = 0.83, p = 0.34). POLE mutations significantly protected against lymph node metastases (OR = 0.202, p = 0.001), and have no clear association with lymph-vascular space invasion (OR = 0.967, 95% 0.713–1.310, p = 0.826). The tumors are predominantly of low ESMO risk stratification distribution (40.356%; 95% CI: 27.577 to 53.838).

Conclusions

POLE mutations serve as an important biomarker of favorable prognosis in EC. The tumors are characteristically high grade, early stage, and remain localized in the endometrium with reduced likelihood of lymph node metastasis for improved survival prospects and the lowest risk classification. These findings have implications for medical management of EC.

Changing treatments paradigms and role of immunotherapy in recurrent endometrial cancer

PURPOSE OF REVIEW

Over the past decade, the treatment of patients diagnosed with endometrial cancer (EC) shifted away from the use of chemotherapy to more novel targeted therapy and immunotherapy approaches.

RECENT FINDINGS

The Cancer Genome Atlas data demonstrated different subgroups within ECs, more specifically, it facilitated the identification of predictive biomarkers. In particular, immunotherapies (immuno-oncology (IO)) are active either as monotherapy or in combination with other agents, depending on the biomarker profile of the tumor.

SUMMARY

In May 2017, pembrolizumab was approved for patients with microsatellite instability high (MSI-H) EC. More recently, this approval was extended for patients harvesting tumors with a high tumor mutational burden status. Furthermore, in July 2021, the combination of pembrolizumab and lenvatinib was approved for patients who do not exhibit MSI-H disease. Given the wealth of targets in EC and different targetable mutations, the challenge will be to choose the proper treatment and the proper sequencing to derive the best outcome in the first-line setting and improve outcomes in subsequent settings. This review summarizes the current indications of immunotherapy for the treatment of advanced and recurrent EC. We outline the role of testing for uterine cancer and its implication in therapy management. Finally, we address new concepts for immunotherapy combinations with other therapies.

KLF3 and PAX6 are candidate driver genes in late-stage, MSI-hypermutated endometrioid endometrial carcinomas

Endometrioid endometrial carcinomas (EECs) are the most common histological subtype of uterine cancer. Late-stage disease is an adverse prognosticator for EEC. The purpose of this study was to analyze EEC exome mutation data to identify late-stage-specific statistically significantly mutated genes (SMGs), which represent candidate driver genes potentially associated with disease progression. We exome sequenced 15 late-stage (stage III or IV) non-ultramutated EECs and paired non-tumor DNAs; somatic variants were called using Strelka, Shimmer, SomaticSniper and MuTect. Additionally, somatic mutation calls were extracted from The Cancer Genome Atlas (TCGA) data for 66 late-stage and 270 early-stage (stage I or II) non-ultramutated EECs. MutSigCV (v1.4) was used to annotate SMGs in the two late-stage cohorts and to derive p-values for all mutated genes in the early-stage cohort. To test whether late-stage SMGs are statistically significantly mutated in early-stage tumors, q-values for late-stage SMGs were re-calculated from the MutSigCV (v1.4) early-stage p-values, adjusting for the number of late-stage SMGs tested. We identified 14 SMGs in the combined late-stage EEC cohorts. When the 14 late-stage SMGs were examined in the TCGA early-stage data, only Krüppel-like factor 3 (KLF3) and Paired box 6 (PAX6) failed to reach significance as early-stage SMGs, despite the inclusion of enough early-stage cases to ensure adequate statistical power. Within TCGA, nonsynonymous mutations in KLF3 and PAX6 were, respectively, exclusive or nearly exclusive to the microsatellite instability (MSI)-hypermutated molecular subgroup and were dominated by insertions-deletions at homopolymer tracts. In conclusion, our findings are hypothesis-generating and suggest that KLF3 and PAX6, which encode transcription factors, are MSI target genes and late-stage-specific SMGs in EEC.

Endometrial Cancer Characteristics and Risk of Recurrence

OBJECTIVES

To describe clinicopathologic characteristics and survival outcomes of endometrial adenocarcinomas stratified by mismatch repair (MMR) status.

METHODS

Single-institution, retrospective study of all women with endometrioid adenocarcinomas treated from January 2012 through December 2017. Patients were categorized into one of three groups based on MMR testing: intact MMR expression (MMR+), probable MMR mutation (MMR-), or MLH1 hypermethylation (hMLH1+). Demographics, pathologic characteristics, recurrence rates, and survival differences were analyzed.

RESULTS

In total, 316 women were included in the analysis: 235 (74.4%) patients in the MMR+ group, 10 (3.1%) in the MMR- group, and 71 (22.5%) in the hMLH1+ group. Patients with hMLH1+ were significantly older, exhibited higher-grade histology and presence of lymphovascular space invasion, and were more likely to have received adjuvant treatment. The early stage hMLH1+ patients were more likely to recur (15.3% hMLH1+ vs 2.3% MMR+ vs 12.5% MMR-, P < .001). Hypermethylation remained a significant predictor of recurrence in multivariable analysis (odds ratio, 5.09; 95% confidence interval [CI], 1.54-16.86; P = .008). Recurrence-free survival was significantly reduced in early stage hMLH1+ (hazard ratio, 7.40; 95% CI, 2.80-21.62; P < .001).

CONCLUSIONS

Women with hMLH1+ endometrial cancer have worse prognostic features and recur more frequently, even in patients traditionally considered low risk for recurrence.

Effect of Mismatch Repair Status on Outcome of Early-Stage Grade 1 to 2 Endometrial Cancer Treated With Vaginal Brachytherapy

OBJECTIVES

The objective of this study was to determine if deficiency of mismatch repair (dMMR) proteins in patients with early-stage favorable endometrial cancer treated with vaginal brachytherapy (VB) is associated with increased recurrence.

MATERIALS AND METHODS

A multi-institutional retrospective cohort study of 141 patients with stage I to II grade 1 and 2 endometrioid adenocarcinoma treated with surgery and adjuvant VB was performed to compare recurrence risk in dMMR (n=41) versus MMR-preserved (pMMR) (n=100). Additional clinical and pathologic risk factors were also collected. Univariate analysis and multivariable analysis Cox regression analysis was performed to identify factors associated with any recurrence. Kaplan-Meier method and log rank test were used to compare recurrence free survival and overall survival (OS).

RESULTS

Median follow up was 42 months. Forty-one patients (29%) were dMMR. There were 7 recurrences (17%) in dMMR versus 4 recurrences (4%) in pMMR (P=0.009). On univariate analysis of any recurrence, both dMMR (hazard ratio: 5.3, P=0.008) and stage (hazard ratio: 3.8, P=0.05) were statistically significantly associated with time to first recurrence. The 5-year recurrence free survival was 90% (95% CI: 73%-96%) in pMMR versus 61.0% (95% CI: 19%-86%) in dMMR (P=0.003). Five-year OS was 96% (95% CI: 76%-99%) in pMMR versus 86% (95% CI: 62%-95%) in dMMR (P=0.03).

CONCLUSIONS

MMR deficiency in stage I to II grade 1 to 2 endometrial cancer patients treated with adjuvant VB alone was associated with statistically significant increased risk for any recurrence and worse OS. MMR status may be an important prognosticator in this cohort of patients warranting adjuvant treatment intensification in the clinical trial setting.

Postoperative Adjuvant Chemoradiotherapy Versus Chemotherapy Alone for Stage III Endometrial Cancer: A Multicenter Retrospective Study

Introduction

We aimed to evaluate the efficacy and toxicity of the combination of 6 cycles of chemotherapy and radiation therapy compared with chemotherapy alone as postoperative adjuvant therapy for patients with stage III endometrial cancer.

Methods

This retrospective cohort study included patients with stage III endometrial cancer who received postoperative chemoradiotherapy or chemotherapy alone at 6 hospitals between January 2009 and December 2019. The progression-free survival (PFS) and overall survival (OS) for each treatment group were analyzed using the Kaplan–Meier method. We also assessed differences in toxicity profiles between the treatment groups.

Results

A total of 133 patients met the inclusion criteria. Of these, 80 patients (60.2%) received adjuvant chemoradiotherapy and 53 (39.8%) received chemotherapy alone. The PFS and OS did not differ significantly between the groups. For patients with stage IIIC endometrioid subtype, the chemoradiotherapy group had significantly longer PFS rate than did the chemotherapy alone group (log-rank test, P = .019), although there was no significant difference in the OS (log-rank test, P = .100). CRT was identified as a favorable prognostic factor for PFS in multivariate analysis (adjusted HR, .37; 95% CI, .16-.87; P = .022). Patients treated with chemoradiotherapy more frequently suffered from grade 4 neutropenia (73.8% vs 52.8%; P = .018) and grade 3 or worse thrombocytopenia (36.3% vs 9.4%; P = .001) compared with the chemotherapy alone group. There were no differences between the 2 treatment groups in the frequency of toxicity-related treatment discontinuation or dose reduction.

Conclusion

We confirmed that chemoradiotherapy yields longer progression-free survival than does chemotherapy alone for patients with stage IIIC endometrioid endometrial cancer, with an acceptable toxicity profile.

Risk Stratification of Endometrial Cancer Patients: FIGO Stage, Biomarkers and Molecular Classification

Endometrial cancer (EC) is the most common gynaecologic malignancy in developed countries. The main challenge in EC management is to correctly estimate the risk of metastases at diagnosis and the risk to develop recurrences in the future. Risk stratification determines the need for surgical staging and adjuvant treatment. Detection of occult, microscopic metastases upstages patients, provides important prognostic information and guides adjuvant treatment. The molecular classification subdivides EC into four prognostic subgroups: POLE ultramutated; mismatch repair deficient (MMRd); nonspecific molecular profile (NSMP); and TP53 mutated (p53abn). How surgical staging should be adjusted based on preoperative molecular profiling is currently unknown. Moreover, little is known whether and how other known prognostic biomarkers affect prognosis prediction independent of or in addition to these molecular subgroups. This review summarizes the factors incorporated in surgical staging (i.e., peritoneal washing, lymph node dissection, omentectomy and peritoneal biopsies), and its impact on prognosis and adjuvant treatment decisions in an era of molecular classification of EC. Moreover, the relation between FIGO stage and molecular classification is evaluated including the current gaps in knowledge and future perspectives.

Prognostic impact of mismatch repair deficiency in high- and low-intermediate-risk, early-stage endometrial cancer following vaginal brachytherapy

OBJECTIVES

To examine the impact of mismatch repair (MMR) status on prognosis among patients with high- and low-intermediate-risk endometrioid endometrial cancer (EEC) treated with vaginal brachytherapy (VBT).

MATERIALS/METHODS

198 stage I-II EEC patients with known MMR status treated with adjuvant VBT were identified. Both low-intermediate (LIR) and high-intermediate-risk (HIR) patients were included. Clinical characteristics were compared between patients with proficient and deficient mismatch repair (pMMR and dMMR) using Fisher's exact tests for categorical variables and t-tests for continuous variables. Recurrence-free survival (RFS) and overall survival (OS) were analyzed with Kaplan-Meier estimates, the log-rank test, and Cox proportional hazards regression.

RESULTS

Patients with dMMR compared to pMMR were more likely to have grade 2-3 tumors (75% vs. 57%, p = 0.006), lympho-vascular invasion (40% vs. 25%, p = 0.034), and HIR classification (65% vs. 49%, p = 0.011). Three-year RFS was inferior for dMMR compared to pMMR patients (75% vs. 96%, p = 0.001). dMMR patients compared to pMMR had similarly reduced 3-year RFS within the LIR (74% vs. 100%, p = 0.026) and HIR (75% vs. 91%, p = 0.038) subgroups. Three-year OS was not different between dMMR/pMMR patients (98% vs. 97%, p = 0.653) or HIR/LIR patients (97% vs. 97%, p = 0.999). On multivariable Cox regression, dMMR status was a significant prognostic variable for RFS (HR 3.774, CI 1.495-9.526, p = 0.005), though it was not significant for OS.

CONCLUSION

Following VBT, patients with dMMR have poorer RFS compared to pMMR patients regardless of HIR/LIR risk classification. The prognosis of intermediate-risk EEC patients may lie more on a continuum dependent on molecular features rather than distinct clinicopathologic risk categories.