A phase 2 evaluation of pembrolizumab for recurrent Lynch-like versus sporadic endometrial cancers with microsatellite instability

A tale of two pathways: Review of immune checkpoint inhibitors in DNA mismatch repair-deficient and microsatellite instability-high endometrial cancers

The DNA mismatch repair (MMR) pathway is critical for correcting DNA mismatches generated during DNA replication. MMR-deficiency (MMR-D) leads to microsatellite instability (MSI) associated with an increased mutation rate, driving cancer development. This is particularly relevant in endometrial cancer (EC) as 25%-30% of tumors are of MMR-D/MSI-high (MSI-H) phenotype. Comprehensive assessment using immunohistochemistry (IHC) and sequencing-based techniques are necessary to fully evaluate ECs given the importance of molecular subtyping in staging and prognosis. This also influences treatment selection as clinical trials have demonstrated survival benefits for immune checkpoint inhibitors (ICIs) alone and in combination with chemotherapy for MMR-D/MSI-H EC patients in various treatment settings. As a portion of MMR-D/MSI-H ECs are driven by Lynch syndrome, an inherited cancer predisposition syndrome that is also associated with colorectal cancer, this molecular subtype also prompts germline assessment that can affect at-risk family members. Additionally, heterogeneity in the tumor immune microenvironment and tumor mutation burden (TMB) have been described by MMR mechanism, meaning MLH1 promoter hypermethylation versus germline/somatic MMR gene mutation, and this may affect response to ICI therapies. Variations by ancestry in prevalence and mechanism of MMR-D/MSI-H tumors have also been reported and may influence health disparities given observed differences in tumors of Black compared to White patients which may affect ICI eligibility. These observations highlight the need for additional prospective studies to evaluate the nuances regarding MMR-D heterogeneity as well as markers of resistance to inform future trials of combination therapies to further improve outcomes for patients with EC.

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.

Nivolumab for mismatch-repair-deficient or hypermutated gynecologic cancers: a phase 2 trial with biomarker analyses

Programmed death-1 (PD-1) inhibitors are approved for therapy of gynecologic cancers with DNA mismatch repair deficiency (dMMR), although predictors of response remain elusive. We conducted a single-arm phase 2 study of nivolumab in 35 patients with dMMR uterine or ovarian cancers. Co-primary endpoints included objective response rate (ORR) and progression-free survival at 24 weeks (PFS24). Secondary endpoints included overall survival (OS), disease control rate (DCR), duration of response (DOR) and safety. Exploratory endpoints included biomarkers and molecular correlates of response. The ORR was 58.8% (97.5% confidence interval (CI): 40.7-100%), and the PFS24 rate was 64.7% (97.5% one-sided CI: 46.5-100%), meeting the pre-specified endpoints. The DCR was 73.5% (95% CI: 55.6-87.1%). At the median follow-up of 42.1 months (range, 8.9-59.8 months), median OS was not reached. One-year OS rate was 79% (95% CI: 60.9-89.4%). Thirty-two patients (91%) had a treatment-related adverse event (TRAE), including arthralgia (n = 10, 29%), fatigue (n = 10, 29%), pain (n = 10, 29%) and pruritis (n = 10, 29%); most were grade 1 or grade 2. Ten patients (29%) reported a grade 3 or grade 4 TRAE; no grade 5 events occurred. Exploratory analyses show that the presence of dysfunctional (CD8+PD-1+) or terminally dysfunctional (CD8+PD-1+TOX+) T cells and their interaction with programmed death ligand-1 (PD-L1)+ cells were independently associated with PFS24. PFS24 was associated with presence of MEGF8 or SETD1B somatic mutations. This trial met its co-primary endpoints (ORR and PFS24) early, and our findings highlight several genetic and tumor microenvironment parameters associated with response to PD-1 blockade in dMMR cancers, generating rationale for their validation in larger cohorts.ClinicalTrials.gov identifier: NCT03241745 .

Molecular features for timely cancer diagnosis and treatment - tumors of the ovary, fallopian tube and endometrium

Gynecologic pathology has moved, within only a few years, from being a diagnostic area devoid of molecular testing into a diagnostic discipline in which such analyses are becoming routine. The direct relevance of molecular characterization to the choice of treatment of patients with carcinomas originating in both the uterus and adnexae makes it likely that such testing will only expand along with our understanding of the molecular make-up of these tumors. As a consequence, gynecologic pathologists have become an integral part of patient management, rather than lab personnel providing external services.In parallel, molecular testing is expanding as a tool for diagnosing rare tumors affecting these organs, including soft tissue tumors, sex cord-stromal tumors and germ cell tumors, as well as other rare entities. Increased knowledge in this area bears directly on the ability to diagnose these tumors in a reproducible manner, as well as recognize and consult on genetic diseases. Hopefully, despite the inherent difficulty in studying rare cancers, it will also translate into new therapeutic options for the malignant ones among these rare cancers.

The function and immune role of cuproptosis associated hub gene in Barrett's esophagus and esophageal adenocarcinoma

Barrett's esophagus (BE) is a precancerous lesion of esophageal adenocarcinoma (EAC), with approximately 3-5% of patients developing EAC. Cuproptosis is a kind of programmed cell death phenomenon discovered in recent years, which is related to the occurrence and development of many diseases. However, its role in BE and EAC is not fully understood. We used single sample Gene Set Enrichment Analysis (ssGSEA) for differential analysis of BE in the database, followed by enrichment analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO) and GSEA, Protein-Protein Interaction (PPI), Weighted Gene Co-expression Network Analysis (WGCNA), Receiver Operating Characteristic Curve (ROC) and finally Quantitative Real Time Polymerase Chain Reaction (qRT-PCR) and immunohistochemistry (IHC) of clinical tissues. Two hub genes can be obtained by intersection of the results obtained from the cuproptosis signal analysis based on BE. The ROC curves of these two genes predicted EAC, and the Area Under the Curve (AUC) values could reach 0.950 and 0.946, respectively. The mRNA and protein levels of Centrosome associated protein E (CENPE) and Shc SH2 domain binding protein 1 (SHCBP1) were significantly increased in clinical EAC tissues. When they were grouped by protein expression levels, high expression of CENPE or SHCBP1 had a poor prognosis. The CENPE and SHCBP1 associated with cuproptosis may be a factor promoting the development of BE into EAC which associated with the regulation of NK cells and T cells.

Digging into phenotype change in mismatch repair deficient endometrial carcinoma and treatment with immune checkpoint inhibition, a case report

•False negative cases for mismatch repair determination by immunohistochemistry may occur.•The mismatch repair phenotype in endometrial carcinoma impacts on therapeutic decision making.•Retesting for mismatch repair at relapse of endometrial carcinoma should be considered.

Differential outcomes and immune checkpoint inhibitor response among endometrial cancer patients with MLH1 hypermethylation versus MLH1 "Lynch-like" mismatch repair gene mutation

OBJECTIVES

To identify differential survival outcomes and immune checkpoint inhibitor (ICI) response in MLH1 hypermethylated versus MLH1 mutated ("Lynch-like") endometrial tumors and determine whether their molecular profiles can elucidate the differential outcomes.

METHODS

1673 mismatch repair deficient endometrial tumors were analyzed by next-generation sequencing and whole transcriptome sequencing (Caris Life Sciences, Phoenix, AZ). PD-L1, ER, and PR were tested by immunohistochemistry and immune cell infiltrates were calculated using MCP-counter. Significance was determined using Chi-square and Mann-Whitney U tests and adjusted for multiple comparisons. Overall survival (OS) was depicted using Kaplan-Meier survival curves.

RESULTS

The endometrial cancer cohort comprised 89.2% patients with MLH1 hypermethylated tumors and 10.8% with MLH1 mutated tumors, with median ages of 67 and 60 years, respectively (p < 0.01). Patients with MLH1 hypermethylated tumors had significantly worse OS and trended toward worse OS following ICI treatment than patients with MLH1 mutated tumors. The immune microenvironment of MLH1 hypermethylated relative to MLH1 mutated was characterized by decreased PD-L1 positivity, immune checkpoint gene expression, immune cell infiltration, T cell inflamed scores, and interferon gamma (IFNγ) scores. MLH1 hypermethylation was also associated with decreased mutation rates in TP53 and DNA damage repair genes, but increased rates of JAK1, FGFR2, CCND1, and PTEN mutations, as well as increased ER and PR positivity.

CONCLUSIONS

Endometrial cancer patients with MLH1 hypermethylation display significantly decreased survival and discrepant immunotherapy responses compared to patients with MLH1 mutated tumors, which was associated with differential mutational profiles, a more immune cold phenotype, and increased ER/PR expression in MLH1 hypermethylated tumors. Providers may consider early transition from single agent ICI to a multi-agent regimen or hormonal therapy for patients with MLH1 hypermethylated tumors.

The Significance of International Federation of Gynecology and Obstetrics Grading in Microsatellite Instability-High and POLE-Mutant Endometrioid Endometrial Carcinoma

With the advancement of diagnostic molecular technology and the molecular classification of endometrial endometrioid carcinoma (EEC), it remains to be seen whether conventional International Federation of Gynecology and Obstetrics (FIGO) grading retains clinical significance in certain molecular subtypes of EECs. In this study, we explored the clinical significance of FIGO grading in microsatellite instability-high (MSI-H) and POLE-mutant EECs. A total of 162 cases of MSI-H EECs and 50 cases of POLE-mutant EECs were included in the analysis. Significant differences in tumor mutation burden (TMB), progression-free survival, and disease-specific survival were seen between the MSI-H and POLE-mutant cohorts. Within the MSI-H cohort, there were statistically significant differences in TMB and stage at presentation across FIGO grades, but not survival. Within the POLE-mutant cohort, there was significantly greater TMB with increasing FIGO grade, but there were no significant differences in stage or survival. In both the MSI-H and POLE-mutant cohorts, log-rank survival analysis showed no statistically significant difference in progression-free and disease-specific survival across FIGO grades. Similar findings were also seen when a binary grading system was utilized. Since FIGO grade was not associated with survival, we conclude that the intrinsic biology of these tumors, characterized by their molecular profile, may override the significance of FIGO grading.

Targeting DNA Damage Repair and Immune Checkpoint Proteins for Optimizing the Treatment of Endometrial Cancer

The dependence of cancer cells on the DNA damage response (DDR) pathway for the repair of endogenous- or exogenous-factor-induced DNA damage has been extensively studied in various cancer types, including endometrial cancer (EC). Targeting one or more DNA damage repair protein with small molecules has shown encouraging treatment efficacy in preclinical and clinical models. However, the genes coding for DDR factors are rarely mutated in EC, limiting the utility of DDR inhibitors in this disease. In the current review, we recapitulate the functional role of the DNA repair system in the development and progression of cancer. Importantly, we discuss strategies that target DDR proteins, including PARP, CHK1 and WEE1, as monotherapies or in combination with cytotoxic agents in the treatment of EC and highlight the compounds currently being evaluated for their efficacy in EC in clinic. Recent studies indicate that the application of DNA damage agents in cancer cells leads to the activation of innate and adaptive immune responses; targeting immune checkpoint proteins could overcome the immune suppressive environment in tumors. We further summarize recently revolutionized immunotherapies that have been completed or are now being evaluated for their efficacy in advanced EC and propose future directions for the development of DDR-based cancer therapeutics in the treatment of EC.

Immune escape and resistance to immunotherapy in mismatch repair deficient tumors

Up to 30% of colorectal, endometrial and gastric cancers have a deficiency in mismatch repair (MMR) protein expression due to either germline or epigenetic inactivation. Patients with Lynch Syndrome who inherit an inactive MMR allele have an up to 80% risk for developing a mismatch repair deficient (MMRd) cancer. Due to an inability to repair DNA, MMRd tumors present with genomic instability in microsatellite regions (MS). Tumors with high MS instability (MSI-H) are characterized by an increased frequency of insertion/deletions (indels) that can encode novel neoantigens if they occur in coding regions. The high tumor antigen burden for MMRd cancers is accompanied by an inflamed tumor microenvironment (TME) that contributes to the clinical effectiveness of anti-PD-1 therapy in this patient population. However, between 40 and 70% of MMRd cancer patients do not respond to treatment with PD-1 blockade, suggesting that tumor-intrinsic and -extrinsic resistance mechanisms may affect the success of checkpoint blockade. Immune evasion mechanisms that occur during early tumorigenesis and persist through cancer development may provide a window into resistance pathways that limit the effectiveness of anti-PD-1 therapy. Here, we review the mechanisms of immune escape in MMRd tumors during development and checkpoint blockade treatment, including T cell dysregulation and myeloid cell-mediated immunosuppression in the TME. Finally, we discuss the development of new therapeutic approaches to tackle resistance in MMRd tumors, including cancer vaccines, therapies targeting immunosuppressive myeloid programs, and immune checkpoint combination strategies.

Could Inhibiting the DNA Damage Repair Checkpoint Rescue Immune-Checkpoint-Inhibitor-Resistant Endometrial Cancer?

Endometrial cancer (EC) is increasingly undermining female health worldwide, with poor survival rates for advanced or recurrent/metastatic diseases. The application of immune checkpoint inhibitors (ICIs) has opened a window of opportunity for patients with first-line therapy failure. However, there is a subset of patients with endometrial cancer who remain insensitive to immunotherapy alone. Therefore, it is necessary to develop new therapeutic agents and further explore reliable combinational strategies to optimize the efficacy of immunotherapy. DNA damage repair (DDR) inhibitors as novel targeted drugs are able to generate genomic toxicity and induce cell death in solid tumors, including EC. Recently, growing evidence has demonstrated the DDR pathway modulates innate and adaptive immunity in tumors. In this review, we concentrate on the exploration of the intrinsic correlation between DDR pathways, especially the ATM-CHK2-P53 pathway and the ATR-CHK1-WEE1 pathway, and oncologic immune response, as well as the feasibility of adding DDR inhibitors to ICIs for the treatment of patients with advanced or recurrent/metastatic EC. We hope that this review will offer some beneficial references to the investigation of immunotherapy and provide a reasonable basis for "double-checkpoint inhibition" in EC.

Hereditary cancer syndromes

Hereditary cancer syndromes (HCSs) are arguably the most frequent category of Mendelian genetic diseases, as at least 2% of presumably healthy subjects carry highly-penetrant tumor-predisposing pathogenic variants (PVs). Hereditary breast-ovarian cancer and Lynch syndrome make the highest contribution to cancer morbidity; in addition, there are several dozen less frequent types of familial tumors. The development of the majority albeit not all hereditary malignancies involves two-hit mechanism, i.e. the somatic inactivation of the remaining copy of the affected gene. Earlier studies on cancer families suggested nearly fatal penetrance for the majority of HCS genes; however, population-based investigations and especially large-scale next-generation sequencing data sets demonstrate that the presence of some highly-penetrant PVs is often compatible with healthy status. Hereditary cancer research initially focused mainly on cancer detection and prevention. Recent studies identified multiple HCS-specific drug vulnerabilities, which translated into the development of highly efficient therapeutic options.

Lynch Syndrome and Gynecologic Tumors: Incidence, Prophylaxis, and Management of Patients with Cancer

This review provides a comprehensive update on recent evidence regarding gynecologic tumors associated with Lynch Syndrome (LS). Endometrial cancer (EC) and ovarian cancer (OC) are the first and second most common gynecologic malignancies in developed countries, respectively, and LS is estimated to be the hereditary cause in 3% of both EC and OC. Despite the increasing evidence on LS-related tumors, few studies have analyzed the outcomes of LS-related EC and OC stratified by mutational variant. This review aims to provide a comprehensive overview of the literature and comparison between updated international guidelines, to help outline a shared pathway for the diagnosis, prevention, and management of LS. Through the widespread adoption of the immunohistochemistry-based Universal Screening, LS diagnosis and identification of mutational variants could be standardized and recognized by international guidelines as a feasible, reproducible, and cost-effective method. Furthermore, the development of a better understanding of LS and its mutational variants will support our ability to better tailor EC and OC management in terms of prophylactic surgery and systemic treatment in the light of the promising results shown by immunotherapy.

Distinct Mechanisms of Mismatch-Repair Deficiency Delineate Two Modes of Response to Anti-PD-1 Immunotherapy in Endometrial Carcinoma

Mismatch repair-deficient (MMRd) cancers have varied responses to immune-checkpoint blockade (ICB). We conducted a phase II clinical trial of the PD-1 inhibitor pembrolizumab in 24 patients with MMRd endometrial cancer (NCT02899793). Patients with mutational MMRd tumors (6 patients) had higher response rates and longer survival than those with epigenetic MMRd tumors (18 patients). Mutation burden was higher in tumors with mutational MMRd compared with epigenetic MMRd; however, within each category of MMRd, mutation burden was not correlated with ICB response. Pretreatment JAK1 mutations were not associated with primary resistance to pembrolizumab. Longitudinal single-cell RNA-seq of circulating immune cells revealed contrasting modes of antitumor immunity for mutational versus epigenetic MMRd cancers. Whereas effector CD8+ T cells correlated with regression of mutational MMRd tumors, activated CD16+ NK cells were associated with ICB-responsive epigenetic MMRd tumors. These data highlight the interplay between tumor-intrinsic and tumor-extrinsic factors that influence ICB response.

SIGNIFICANCE

The molecular mechanism of MMRd is associated with response to anti-PD-1 immunotherapy in endometrial carcinoma. Tumors with epigenetic MMRd or mutational MMRd are correlated with NK cell or CD8+ T cell-driven immunity, respectively. Classifying tumors by the mechanism of MMRd may inform clinical decision-making regarding cancer immunotherapy. This article is highlighted in the In This Issue feature, p. 247.

Dynamic host immunity and PD-L1/PD-1 blockade efficacy: developments after "IFN-γ from lymphocytes induces PD-L1 expression and promotes progression of ovarian cancer"

In the article titled "IFN-γ from lymphocytes induces PD-L1 expression and promotes progression of ovarian cancer" in 2015, we showed that PD-L1 expression is induced by IFN-γ from lymphocytes in the tumour microenvironment. This article proposed that PD-L1 expression in cancer cells is not stable but varies among cases, or even within a case, which is influenced by the stromal infiltration of cytotoxic lymphocytes. Immune-checkpoint inhibitors, especially anti-PD-1/PD-L1 therapies, are now widely used to treat various types of cancer. Predictive biomarkers for the efficacy of immune-checkpoint inhibitors include PD-L1 expression, MSI/mismatch repair deficiency and high tumour mutation burden. However, clinical trials have proven that their use in ovarian cancer is still challenging. Reliable biomarkers and new treatment strategies may be sought by elucidating the complex immune microenvironment of ovarian cancer. Although the interaction between cytotoxic lymphocytes and PD-1/PD-L1 on tumour cells is at the centre of therapeutic targets, other immune checkpoints and various immunosuppressive cells also play important roles in ovarian cancer. Targeting these role players in combination with PD-1/PD-L1 blockade may be a promising therapeutic strategy.

Current Evidence-Based Systemic Therapy for Advanced and Recurrent Endometrial Cancer

Endometrial cancer (EC) is the most common gynecologic malignancy, with worldwide increasing incidence and disease-associated mortality. Although most patients with EC are diagnosed with early-stage disease, systemic treatment options for patients with advanced or recurrent EC have historically been limited. EC-focused clinical trials and the ensuing therapeutic landscape have expanded since The Cancer Genome Atlas (TCGA) identified 4 distinct EC subgroups associated with differential survival. This endeavor revolutionized our understanding of the genomic characterization of EC as well as molecular drivers of this heterogeneous malignancy, leading to precision oncology approaches to therapeutics and advancement in treatment options. This review describes the current status of and recent advancements in therapeutic options for patients with advanced and recurrent EC. The NCCN Guidelines for Uterine Neoplasms provide detailed recommendations regarding the diagnosis, workup, and management of EC.

A Hypoxia Molecular Signature-Based Prognostic Model for Endometrial Cancer Patients

Endometrial cancer has the highest incidence of uterine corpus cancer, the sixth most typical cancer in women until 2020. High recurrence rate and frequent adverse events were reported in either standard chemotherapy or combined therapy. Hence, developing precise diagnostic and prognostic approaches for endometrial cancer was on demand. Four hypoxia-related genes were screened for the EC prognostic model by the univariate, LASSO, and multivariate Cox regression analysis from the TCGA dataset. QT-PCR and functional annotation analysis were performed. Associations between predicted risk and immunotherapy and chemotherapy responses were investigated by evaluating expressions of immune checkpoint inhibitors, infiltrated immune cells, m6a regulators, and drug sensitivity. The ROC curve and calibration plot indicated a fair predictability of our prognostic nomogram model. NR3C1 amplification, along with IL-6 and SRPX suppressions, were detected in tumor. High stromal score and enriched infiltrated aDCs and B cells in the high-risk group supported the hypothesis of immune-deserted tumor. Hypoxia-related molecular subtypes of EC were then identified via the gene signature. Cluster 2 patients showed a significant sensitivity to Vinblastine. In summary, our hypoxia signature model accurately predicted the survival outcome of EC patients and assessed translational and transcriptional dysregulations to explore targets for precise medical treatment.

Evaluation of immunotherapy efficacy in gynecologic cancer

Various immunotherapies have demonstrated remarkable success over the past few decades, and have been approved for the treatment of different cancer types. However, patient responses to immunotherapy are variable, and approximately 50% of cases are refractory to these agents. Tumor biomarker-based stratification of cases may therefore help identify subpopulations that are sensitive/resistant to immunotherapy; it may also improve prediction of response in various cancers including gynecologic cancer. These biomarkers include the tumor mutational burden, microsatellite instability, mismatch repair deficiency, T cell-inflamed gene expression profile, programmed cell death protein 1 ligand 1, tumor-infiltrating lymphocytes, and numerous other genomic alterations. Future directions in the treatment of gynecologic cancer include the utilization of these biomarkers to select ideal candidates. This review focused on recent advances in the predictive ability of molecular biomarkers in patients with gynecologic cancer who undergo immunotherapy. The most recent developments in combined immunotherapy and targeted therapy strategies and novel immune interventions against gynecologic cancers have also been discussed.

A rapidly evolving landscape: immune checkpoint inhibitors in pretreated metastatic endometrial cancer

Background and objectives

Endometrial cancer is a common malignancy and recurrences can be fatal. Although platinum-pretreated endometrial tumors are commonly treated with anthracyclines and taxanes, there is no current standard of care. Both immune checkpoint inhibitors (ICIs) and tyrosine kinase inhibitors (TKIs) have been extensively assessed in this setting, including tumors selected for DNA mismatch repair (MMR)/microsatellite instability (MSI) and programmed death-ligand 1 expression status. This review will provide evidence-based guidance on use of ICIs alone or in combination with TKIs in patients with pretreated advanced, persistent, or recurrent metastatic endometrial cancer.

Data sources and methods

Randomized phase II-III trials in unselected populations pretreated, recurrent, or metastatic endometrial cancer and phase I-II trials in biomarker selected populations were identified from PubMed as well as conference proceedings using the key search terms 'immune checkpoint inhibitors', 'endometrial cancer', and 'advanced'.

Results

A total of nine eligible studies were identified assessing ICI monotherapy for biomarker-selected or ICI plus TKI combinations and a dual ICI regimen for biomarker-unselected patients with pretreated recurrent or metastatic endometrial cancer. In MMR/MSI-selected tumors, five phase I/II studies evaluated ICI monotherapy indicating benefit in these patients. Only the phase III KEYNOTE-775 trial reported a statistically significant overall survival improvement for the combination of pembrolizumab plus lenvatinib compared with docetaxel or paclitaxel regardless of MMR/MSI status.

Conclusions

Pembrolizumab plus lenvatinib is indicated for patients with unselected pretreated metastatic endometrial cancer and pembrolizumab monotherapy is a preferred option for patients with MMRd/MSI-H tumors.

Endometrial Cancer in Reproductive Age: Fertility-Sparing Approach and Reproductive Outcomes

Endometrial cancer is the most common gynecologic malignancy in developed countries and approximately 7% of the women with endometrial cancer are below the age of 45. Management of endometrial cancer in young women who desire to maintain fertility presents a unique set of challenges since the standard surgical treatment based on hysterectomy and salpingo-oophorectomy is often not compatible with the patient's goals. A fertility-preserving approach can be considered in selected patients with early stage and low-grade endometrial cancer. An increasing amount of data suggest that oncologic outcomes are not compromised if a conservative approach is utilized with close monitoring until childbearing is completed. If a fertility-preserving approach is not possible, assisted reproductive technologies can assist patients in achieving their fertility goals.

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.

Envafolimab - first PD-1/PD-L1 antibody to be administered by subcutaneous injection for microsatellite instability-high or deficient mismatch repair advanced solid tumors

INTRODUCTION

Programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) inhibitors mobilize and activate the anti-tumor activity of the immune system by blocking the inhibitory effects of the PD-1/PD-L1 signaling pathway in T cells. Several anti-PD-1 or -PD-L1 monoclonal antibodies have been approved for the treatment of advanced solid tumors. However, most of immune checkpoint inhibitors (ICIs) are administered via intravenous infusion, which is inconvenient and leads to unsatisfactory patient compliance in the treatment process. Therefore, subcutaneous envafolimab is to be a potential treatment modality for advanced solid tumors.

AREA COVERED

A phase I clinical trial showed that the safety and pharmacokinetic profiles of envafolimab were similar to those of other traditional antibodies. Additionally, clinical findings from a phase II trial revealed that envafolimab monotherapy exhibited satisfactory clinical therapeutic effects and no significant adverse events in patients with Microsatellite instability-high/deficient mismatch Repair (MSI-H/dMMR) solid tumors who failed at least one line of prior systemic therapy.

EXPERT OPINION

Subcutaneous envafolimab may serve as a more convenient and acceptable treatment modality than those approved PD-1/PD-L1 inhibitors for patients with an advanced solid tumor, which may revolutionize the modes of immunotherapy in the future.

Immune Checkpoint Inhibitors and Mismatch Repair Status in Advanced Endometrial Cancer: Elective Affinities

Since endometrial cancers (ECs) are frequently TMB-H and MSI-H/dMMR tumors, this element has provided the rationale for testing immune checkpoint inhibitors (ICIs), which have recently emerged as a potential game-changer. However, several questions remain to be addressed, including the identification of patients who may benefit from the addition of ICIs as well as those who do not need immunotherapy. In the current paper, we provide an overview of the clinical development of immunotherapy in advanced or recurrent EC, discussing the role of MMR and the "elective affinities" between ICIs and this predictive biomarker in this setting.

High Mutation Burden in ER-Positive/HER2-Negative/Luminal Breast Cancers

Background: Tumor mutation burden (TMB) is arising as a useful marker of checkpoint inhibitors’ effectiveness in cancer patients in general and has been proposed as predictive in breast cancers. Despite the initial success of checkpoint inhibitors in triple-negative breast cancer, ER-positive breast cancers are less amenable to immunotherapy treatments due to the lower immunogenicity of this subset, associated with lower TMB and less pronounced inflammatory cell infiltration. However, a minority of ER-positive breast cancers do have a higher TMB and could be targets of immune checkpoint inhibitors. Methods: This investigation uses publicly available genomic data to examine ER-positive/HER2-negative or luminal breast cancers with high mutation numbers and compare them with cancers of the same subtype and low mutation numbers. Clinical characteristics and molecular correlates according to mutation numbers are described. Results: ER-positive/HER2-negative and luminal breast cancers with high mutation numbers have a higher prevalence of PIK3CA mutations and in some of the series examined mutations in TP53 and CDH1. A significant proportion of cancers with high mutation numbers carry mutations in microsatellite instability genes and genes involved in DNA damage response. Despite these differences, the prognosis of ER-positive/HER2-negative and luminal breast cancers with high mutation numbers is not significantly different compared to counterparts with lower mutation counts. Conclusions: These data may inform the potential suitability of these cancers for immunotherapy and could guide the development of rational combination therapies based on immune checkpoint inhibitors with other targeted drugs.

Angiogenesis: A Pivotal Therapeutic Target in the Drug Development of Gynecologic Cancers

Simple Summary

Angiogenesis, defined as the abnormal development of new blood vessels in cancer, is a key component of cancer development. Clinical trials have proven that angiogenesis blockers can be effective in halting cancer growth across numerous types of gynecologic cancers. This review discusses the mechanisms of angiogenesis in gynecologic cancers, current practices and areas for development.

Abstract

Since the discovery of angiogenesis and its relevance to the tumorigenesis of gynecologic malignancies, a number of therapeutic agents have been developed over the last decade, some of which have become standard treatments in combination with other therapies. Limited clinical activity has been demonstrated with anti-angiogenic monotherapies, and ongoing trials are focused on combination strategies with cytotoxic agents, immunotherapies and other targeted treatments. This article reviews the science behind angiogenesis within the context of gynecologic cancers, the evidence supporting the targeting of these pathways and future directions in clinical trials.

Endometrial Cancer: Transitioning from Histology to Genomics

Endometrial carcinoma (EC) is traditionally treated with surgery and adjuvant treatment depending on clinicopathological risk factors. The genomic analysis of EC in 2013 and subsequent studies using immunohistochemistry have led to the current EC molecular classification into: polymerase epsilon mutated (POLEmut), p53 abnormal (p53abn), mismatch repair deficient (MMRd), and no specific molecular profile (NSMP). The four groups have prognostic value and represent a promising tool for clinical decision-making regarding adjuvant treatment. Molecular classification was integrated into the recent European Society of Gynecologic Oncology (ESGO) management guidelines. POLEmut EC has favorable outcomes and retrospective studies found that omitting adjuvant treatment is safe in this group; two prospective clinical trials, PORTEC-4 and TAPER, are ongoing to assess this. p53 abn is associated with increased recurrence, decreased survival, and benefitted from chemotherapy in the PORTEC-3 subgroup molecular analysis. The clinical trials PORTEC-4a and CANSTAMP will prospectively assess this. MMRd and NSMP groups have intermediate prognosis and will likely continue to rely closely on clinicopathological features for adjuvant treatment decisions. In addition, the molecular classification has led to exploring novel treatments such as checkpoint inhibitors. Overall, the molecular perspective on EC and associated clinical trials will likely refine EC risk stratification to optimize care and avoid overtreatment.