Universal endometrial cancer tumor typing: How much has immunohistochemistry, microsatellite instability, and MLH1 methylation improved the diagnosis of Lynch syndrome across the population?

Insights into MLH1 Methylation in Endometrial Adenocarcinoma through Pyrosequencing Analysis: A Retrospective Observational Study

Background: In cancer care, the MLH1 gene is crucial for DNA mismatch repair (MMR), serving as a vital tumor suppressor. Evaluating MLH1 protein expression status, followed by analysis of MLH1 promoter methylation, has become a key diagnostic and prognostic approach. Our study investigates the complex link between MLH1 methylation and prognosis in endometrial adenocarcinoma (EA) patients. Methodology: MLH1 methylation status was accessed by a Pyrosequencing (PSQ) assay. Qualitative positivity for methylation was established if it exceeded the 11% cut-off; as well, a quantitative methylation analysis was conducted to establish correlations with clinicopathological data, relapse-free survival, and disease-free survival. Results: Our study revealed that 33.3% of patients without MLH1 methylation experienced relapses, surpassing the 23.3% in patients with methylation. Furthermore, 16.7% of patients without methylation succumbed to death, with a slightly higher rate of 17.6% in methylated patients. Qualitative comparisons highlighted that the mean methylation rate in patients experiencing relapse was 35.8%, whereas in those without relapse, it was 42.2%. This pattern persisted in disease-specific survival (DSS), where deceased patients exhibited a higher mean methylation level of 49.1% compared to living patients with 38.8%. Conclusions: Our findings emphasize the efficacy of PSQ for evaluating MLH1 methylation. While unmethylation appears to be associated with a higher relapse rate, the survival rate does not seem to be influenced by methylation. Quantitative percentages suggest that elevated MLH1 methylation is linked to relapse and mortality, though a study with a larger sample size would be essential for statistically significant results.

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.

Participation of Long Noncoding RNA FOXP4-AS1 in the Development and Progression of Endometrioid Carcinoma with Epigenetically Silencing DUSP5

Background: Long noncoding RNAs (lncRNAs), as emerging regulators of a wide variety of biological processes via diverse mechanisms, have been demonstrated to be of increasing importance in biology. Genome-wide association studies of tumor samples have identified several lncRNAs as either oncogenes or tumor suppressors in various types of cancers. In recent years, the importance of lncRNAs, especially in endometrioid cancer (EEC), has become increasingly well understood. The lncRNA Forkhead box P4 antisense RNA 1 (FOXP4-AS1) has been reported to fulfill roles in several types of cancers; however, the main biological function and associated underlying molecular mechanism of FOXP4-AS1 in EEC have yet to be fully elucidated. Materials and Methods: The present study therefore aimed to investigate how RNA FOXP4-AS1 may participate in the development and progression of endometrioid carcinoma tissues. To meet this aim, in the present study, the expression level of FOXP4-AS1 was investigated in endometrioid carcinoma tissues and matching nearby normal endometrial tissues collected from patients receiving surgery at the hospital, and a series of molecular biological assays were performed to investigate the effect of FOXP4-AS1 on cell proliferation, cell migration, and cell invasion, and so on. Results: An increased concentration of FOXP4-AS1 was identified in endometrioid carcinoma samples and cell lines compared with the corresponding controls, and this lncRNA was found to be positively correlated with advanced FIGO stages in patients with endometrial cancer. Furthermore, knocking down endogenous FOXP4-AS1 led to a significant reduction in the colony formation number and a significant inhibition of cell proliferation, cell migration, and cell invasion in endometrioid carcinoma cells. Moreover, dual-specificity phosphatase 5 (DUSP5), which is lowly expressed in endometrioid carcinoma tissues cells and negatively modulated by FOXP4-AS1, was identified as the downstream target molecule of FOXP4-AS1. Subsequently, the mechanistic experiments confirmed that, through binding to enhancer of zeste homolog 2 (EZH2; one of the catalytic subunits of polycomb repressive complex 2 [PRC2]), FOXP4-AS1 could epigenetically suppress the expression of DUSP5. Finally, the oncogenic function of the FOXP4-AS1/EZH2/DUSP5 axis in endometrioid carcinoma was confirmed via rescue assays. Conclusions: The findings of the present study have highlighted how FOXP4-AS1 fulfills an oncogenic role in endometrioid carcinoma, and targeting FOXP4-AS1 and its pathway may provide new biomarkers for patients with endometrioid carcinoma.

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.

Molecular pathology as basis for timely cancer diagnosis and therapy

Precision and personalized therapeutics have witnessed significant advancements in technology, revolutionizing the capabilities of laboratories to generate vast amounts of genetic data. Coupled with computational resources for analysis and interpretation, and integrated with various other types of data, including genomic data, electronic medical health (EMH) data, and clinical knowledge, these advancements support optimized health decisions. Among these technologies, next-generation sequencing (NGS) stands out as a transformative tool in the field of cancer treatment, playing a crucial role in precision oncology. NGS-based workflows are employed across a range of applications, including gene panels, exome sequencing, and whole-genome sequencing, supporting comprehensive analysis of the entire cancer genome, including mutations, copy number variations, gene expression profiles, and epigenetic modifications. By utilizing the power of NGS, these workflows contribute to enhancing our understanding of disease mechanisms, diagnosis confirmation, identifying therapeutic targets, and guiding personalized treatment decisions. This manuscript explores the diverse applications of NGS in cancer treatment, highlighting its significance in guiding diagnosis and treatment decisions, identifying therapeutic targets, monitoring disease progression, and improving patient outcomes.

Diffusion kurtosis imaging with multiple quantitative parameters for predicting microsatellite instability status of endometrial carcinoma

PURPOSE

To explore the value of Diffusion kurtosis imaging (DKI) with multiple quantitative parameters in predicting microsatellite instability (MSI) status in endometrial carcinoma (EC).

METHODS

Data of 38 patients with EC were retrospectively analyzed, including 12 MSI and 26 microsatellite stability (MSS). All patients underwent preoperative 1.5T MR examination. The quantitative values of the DKI sequence in the tumor parenchyma of the two groups, including mean kurtosis (MK), axial kurtosis (Ka), radial kurtosis (Kr), fractional anisotropy (FA), fractional anisotropy of kurtosis (FAk), mean diffusivity (MD), axial diffusivity (Da), and radial diffusivity (Dr) were measured by two observers, respectively.

RESULTS

The MK, Ka, Kr, FA, FAk, MD, Da, and Dr values of the MSI group were 1.074 ± 0.162, 1.253 ± 0.229, 0.886 ± 0.205, 0.207 ± 0.041, 0.397 ± 0.129, 0.890 ± 0.158 μm2/ms, 1.083 ± 0.218 μm2/ms, and 0.793 ± 0.133 μm2/ms, and 0.956 (0.889,1.002), 1.048 ± 0.211, 0.831 ± 0.099, 0.188 ± 0.061, 0.334 (0.241,0.410), 1.043 ± 0.217 μm2/ms, 1.235 ± 0.229 μm2/ms, and 0.946 ± 0.215 μm2/ms in the MSS group. The MK and Ka values of the MSI group were higher than those of the MSS group (P<0.05), while the MD and Dr values were lower than those of the MSS group (P<0.05). The AUC of MK, Ka, MD, and Dr values in predicting MSI status of EC was 0.763, 0.729, 0.731, 0.748, respectively. The sensitivity was 58.3%, 50.0%, 65.4%, 61.5%, and the specificity was 96.2%, 92.3%, 75.0%, 83.3%, respectively.

CONCLUSION

DKI can provide multiple quantitative parameters for predicting the MSI status of EC, and assist gynecologist to optimize the treatment plan for the patients.

Landscape of somatic mutated genes and inherited susceptibility genes in gynecological cancer

Traditionally, gynecological cancers have been classified based on histology. Since remarkable advancements in next-generation sequencing technology have enabled the exploration of somatic mutations in various cancer types, comprehensive sequencing efforts have revealed the genomic landscapes of some common forms of human cancer. The genomic features of various gynecological malignancies have been reported by several studies of large-scale genomic cohorts, including The Cancer Genome Atlas. Although recent comprehensive genomic profiling tests, which can detect hundreds of genetic mutations at a time from cancer tissues or blood samples, have been increasingly used as diagnostic clinical biomarkers and in therapeutic management decisions, germline pathogenic variants associated with hereditary cancers can also be detected using this test. Gynecological cancers are closely related to genetic factors, with approximately 5% of endometrial cancer cases and 20% of ovarian cancer cases being caused by germline pathogenic variants. Hereditary breast and ovarian cancer syndrome and Lynch syndrome are the two major cancer susceptibility syndromes among gynecological cancers. In addition, several other hereditary syndromes have been reported to be associated with gynecological cancers. In this review, we highlight the genes for somatic mutation and germline pathogenic variants commonly seen in gynecological cancers. We first describe the relationship between clinicopathological attributes and somatic mutated genes. Subsequently, we discuss the characteristics and clinical management of inherited cancer syndromes resulting from pathogenic germline variants in gynecological malignancies.

Diagnosis of patients with Lynch syndrome lacking the Amsterdam II or Bethesda criteria

BACKGROUND

Lynch Syndrome (LS) is an autosomal dominant inheritance disorder characterized by genetic predisposition to develop cancer, caused by pathogenic variants in the genes of the mismatch repair system. Cases are detected by implementing the Amsterdam II and the revised Bethesda criteria, which are based on family history.

MAIN BODY

Patients who meet the criteria undergo posterior tests, such as germline DNA sequencing, to confirm the diagnosis. However, these criteria have poor sensitivity, as more than one-quarter of patients with LS do not meet the criteria. It is very likely that the lack of sensitivity of the criteria is due to the incomplete penetrance of this syndrome. The penetrance and risk of developing a particular type of cancer are highly dependent on the affected gene and probably of the variant. Patients with variants in low-penetrance genes have a lower risk of developing a cancer associated with LS, leading to families with unaffected generations and showing fewer clear patterns. This study focuses on describing genetic aspects of LS cases that underlie the lack of sensitivity of the clinical criteria used for its diagnosis.

CONCLUSION

Universal screening could be an option to address the problem of underdiagnosis.

Screening and testing practices for Lynch syndrome in Nova Scotians with endometrial cancer: a descriptive study

BACKGROUND

Identifying people with Lynch syndrome, a genetic condition predisposing those affected to colorectal, endometrial and other cancers, allows for implementation of risk-reducing strategies for patients and their families. The goal of this study was to describe screening and testing practices for this condition among people with endometrial cancer in Nova Scotia, Canada, and to determine the prevalence of Lynch syndrome in this population.

METHODS

All patients diagnosed with endometrial cancer in Nova Scotia between May 1, 2017, and Apr. 30, 2020 were identified through a provincial gynecologic oncology database. Patients from out of province were excluded. We collected age, body mass index, tumour mismatch repair protein immunohistochemistry results, personal and family histories, and germline testing information for all patients.

RESULTS

We identified 465 people diagosed with endometrial cancer during the study period. Most were aged 51 years or older, and had obesity and low-grade early-stage endometrioid tumours. Tumour immunohistochemistry testing was performed in 444 cases (95.5%). Based on local criteria, 189 patients were eligible for genetic counselling, of whom 156 (82.5%) were referred to medical genetics. Of the 98 patients who underwent germline testing, 9 (9.2%) were diagnosed with Lynch syndrome.

INTERPRETATION

The prevalence of Lynch syndrome was at least 1.9% (9/465) in this population. Our results illustrate successful implementation of universal tumour testing; however, there remains a gap in access to genetic counselling.

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.

Germline drivers of gynecologic carcinosarcomas

OBJECTIVES

To describe the prevalence of germline pathogenic variants (gPVs) in endometrial and ovarian carcinosarcomas and determine if gPVs are drivers of carcinosarcoma.

METHODS

Patients with endometrial or ovarian carcinosarcomas who underwent clinical tumor-normal sequencing from 1/1/2015 to 6/1/2021 and consented to germline assessment of ≥76 cancer predisposition genes were included. In patients with gPVs, biallelic inactivation was identified through analysis of loss of heterozygosity and somatic pathogenic alterations.

RESULTS

Of 216 patients identified, 167 (77%) were diagnosed with endometrial carcinosarcoma and 49 (23%) with ovarian carcinosarcoma. Overall, 33 gPVs were observed in 29 patients (13%); 20 gPVs (61%) had biallelic loss in tumors. The rate of high-penetrance gPVs overall was 7% (16 of 216); 88% of high-penetrance gPVs had biallelic loss. In the endometrial carcinosarcoma cohort, 22 gPVs were found in 19 (11%) of 167 patients; 12 gPVs (55%) had biallelic loss in tumors, including 8 (89%) of 9 in high-penetrance gPVs. Among the ovarian carcinosarcoma cohort, 11 gPVs were found in 10 (20%) of 49 patients; 8 gPVs (73%) had biallelic loss in tumors, and all evaluable high-penetrance gPVs (n = 6) had biallelic loss. All gPVs in homologous recombination (BRCA1, BRCA2, RAD51C) and Lynch syndrome (MSH2, MSH6) genes had biallelic loss in tumors (n = 15).

CONCLUSIONS

gPVs in genes affecting homologous recombination- or Lynch-associated mismatch repair exhibited biallelic inactivation within tumors, suggesting likely drivers of gynecologic carcinosarcoma. Our data support germline testing for patients with gynecologic carcinosarcomas, given implications for treatment and risk-reduction in patients and at-risk family members.

Comprehensive analysis of germline drivers in endometrial cancer

BACKGROUND

We sought to determine the prevalence of germline pathogenic variants (gPVs) in unselected patients with endometrial cancer (EC), define biallelic gPVs within tumors, and describe their associations with clinicopathologic features.

METHODS

Germline assessment of at least 76 cancer predisposition genes was performed in patients with EC undergoing clinical tumor-normal Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) sequencing from January 1, 2015, to June 30, 2021. In patients with gPVs, biallelic alterations in ECs were identified through analysis of loss of heterozygosity and somatic PVs. Clinicopathologic variables were compared using nonparametric tests.

RESULTS

Of 1625 patients with EC, 216 (13%) had gPVs, and 15 patients had 2 gPVs. There were 231 gPVs in 35 genes (75 [32%] high penetrance; 39 [17%] moderate penetrance; and 117 [51%] low, recessive, or uncertain penetrance). Compared with those without gPVs, patients with gPVs were younger (P = .002), more often White (P = .009), and less obese (P = .025) and had differences in distribution of tumor histology (P = .017) and molecular subtype (P < .001). Among 231 gPVs, 74 (32%) exhibited biallelic inactivation within tumors. For high-penetrance gPVs, 63% (47 of 75) of ECs had biallelic alterations, primarily affecting mismatch repair (MMR) and homologous recombination related genes, including BRCA1,BRCA2, RAD51D, and PALB2. Biallelic inactivation varied across molecular subtypes with highest rates in microsatellite instability-high (MSI-H) or copy-number (CN)-high subtypes (3 of 12 [25%] POLE, 30 of 77 [39%] MSI-H, 27 of 60 [45%] CN-high, 9 of 57 [16%] CN-low; P < .001).

CONCLUSIONS

Of unselected patients with EC, 13% had gPVs, with 63% of gPVs in high-penetrance genes (MMR and homologous recombination) exhibiting biallelic inactivation, potentially driving cancer development. This supports germline assessment in EC given implications for treatment and cancer prevention.

Amplicon-based NGS test for assessing MLH1 promoter methylation and its correlation with BRAF mutation in colorectal cancer patients

Detecting MLH1 promoter methylation is highly relevant to differentiate between possible Lynch syndrome patients or patients with sporadic causes of MLH1/PMS2 deficiency in colorectal (CRC) and endometrial cancers. Here, we aimed to develop a test for assessing MLH1 promoter methylation based in next generation sequencing (NGS), and to evaluate the concordance of MLH1 methylation and BRAF-V600 mutation status in CRC. For that, we performed a series of experiments with DNA from tumor, saliva and commercial control samples and our in house developed amplicon-based NGS test. In patients' samples, MLH1 methylation above 10% was only observed in tumors with MLH1/PMS2 loss. We confirmed the reproducibility and accuracy of MLH1 promoter analysis performing a serial dilution experiment with completely methylated and unmethylated control DNAs and a comparison between two NGS platforms (Ion Proton and Illumina). In MLH1/PMS2 deficient tumors, the MLH1 methylation status was concordant with the BRAF mutation status in 90% (18/20) of the cases. Our amplicon-based NGS test showed a great sensitivity and specificity for detecting MLH1 methylation in CRC samples, with a high agreement with the evaluation of BRAF mutation. This simple and affordable test could be used as a reflex test to identify patients with sporadic causes of MLH1/PMS2 deficiency in CRC, aiding to genetic test referral and identification of Lynch syndrome patients.

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.

Clinicopathologic Evaluation of CTNNB1 Mutations in High-Intermediate Risk Endometrial Endometrioid Carcinoma

CTNNB1 mutations convey increased risk of recurrence in low-risk endometrial endometrioid carcinoma (EEC). Results from previous high-intermediate risk (HIR) cohorts are mixed. The aims of this study were to correlate CTNNB1 mutational status with clinical outcomes and to evaluate the relationship between CTNNB1 mutations and the 4 prognostic subgroups defined by The Cancer Genome Atlas in HIR EEC. CTNNB1 mutational status was determined by Sanger sequencing of exon 3 of the CTNNB1 gene. Mismatch repair, POLE , p53, and L1 cell-adhesion molecule (L1CAM) status were also evaluated. Descriptive statistics and survival analyses were performed. Eighty-eight cases of HIR EEC were identified, of which 22 (25%) were CTNNB1 mutant ( CTNNB1 -mut) and 66 (75%) were wild-type ( CTNNB1 -WT). Median follow-up was 60 mo. Recurrence occurred in 13/88 (15%) patients. Recurrence rates were not significantly different between patients with CTNNB1- mut and CTNNB1- WT tumors (14% vs. 15%, P =0.86). Recurrence-free survival and overall survival were not significantly different (recurrence-free survival hazard ratio: 0.97, 95% confidence interval: 0.27-3.52, P =0.96; overall survival hazard ratio: 0.23, 95% confidence interval: 0.03-1.71, P =0.15). Mismatch repair deficiency was more prevalent in CTNNB1 -WT compared with CTNNB1 -mut tumors (46% vs. 14%, P =0.01); prevalence of POLE mutations and aberrant p53 were not significantly different. In contrast to patients with low-risk EEC, no differences in recurrence or survival were found in patients with HIR EEC with CTNNB1- mut compared with CTNNB1 -WT tumors.

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

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

From the patient to the population: Use of genomics for population screening

Genomic medicine is expanding from a focus on diagnosis at the patient level to prevention at the population level given the ongoing under-ascertainment of high-risk and actionable genetic conditions using current strategies, particularly hereditary breast and ovarian cancer (HBOC), Lynch Syndrome (LS) and familial hypercholesterolemia (FH). The availability of large-scale next-generation sequencing strategies and preventive options for these conditions makes it increasingly feasible to screen pre-symptomatic individuals through public health-based approaches, rather than restricting testing to high-risk groups. This raises anew, and with urgency, questions about the limits of screening as well as the moral authority and capacity to screen for genetic conditions at a population level. We aimed to answer some of these critical questions by using the WHO Wilson and Jungner criteria to guide a synthesis of current evidence on population genomic screening for HBOC, LS, and FH.

Fertility-sparing treatment for endometrial cancer and atypical endometrial hyperplasia in patients with Lynch Syndrome: Molecular diagnosis after immunohistochemistry of MMR proteins

Introduction

Lynch Syndrome (LS) represents the hereditary condition that is most frequently associated with endometrial cancer (EC). The aim of this study is to assess the presence of Lynch Syndrome (LS) in young women with mismatch repair (MMR)-deficient atypical endometrial hyperplasia (AEH) and non-myoinvasive FIGO G1 endometrioid EC and its possible impact on the outcome of conservative treatment.

Methods

Six MMR-deficient cases identified from a previous cohort of 69 conservatively treated patients were selected to be screened for germline mutations in MMR genes. In each patient, the outcomes of conservative treatment for AEH and EEC, including response, relapse, progression, and pregnancy, were assessed.

Results

Five out of 6 patients underwent genetic test for LS. Three out of these 5 patients showed a positive genetic test. Patient 1 showed the c.942 + 2 T>A heterozygous variant of MSH2 mutation; after 12 months of complete response, she had relapse and progression of disease. Patient 4 showed the c.2459-1G>C variant of MSH2 mutation; after complete response, she failed to achieve pregnancy; she had relapse after 24 months and underwent hysterectomy. Patient 6 showed the c.803 + 1 heterozygous variant of PMS2 mutation; she had relapse of disease after 18 months from the first complete response and then underwent hysterectomy.

Conclusions

In this series, 3 out of 6 women with MMR-deficiency had LS. None of the patients achieved pregnancy, and those who responded to treatment had subsequent relapse of disease. Patients undergoing fertility-sparing treatment for atypical endometrial hyperplasia and endometrial cancer should perform MMR immunohistochemical analysis in order to screen LS.

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

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

Treatment patterns and real-world clinical outcomes in patients with advanced endometrial cancer that are non-microsatellite instability high (non-MSI-high) or mismatch repair proficient (pMMR) in the United States

•

First study to describe real-world outcomes in non-MSI-H/pMMR aEC patients who progressed following prior systemic therapy.

•

MSI/MMR testing was near universal in aEC patients in the US, reflecting the increased awareness of biomarker status.

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Patients on second-line chemo or hormonal therapy had poor clinical outcomes: median OS of 10 months and rwPFS of 5 months.

•

Data suggest an unmet medical need in this population between 2016 and 2019.

Objective

Microsatellite instability (MSI) due to defective DNA mismatch repair has emerged as an actionable biomarker in advanced endometrial cancer (aEC). Currently, there are no treatment patterns and outcomes data in non-MSI-high (non-MSI-H) or mismatch repair proficient (pMMR) aEC patients following prior systemic therapy (FPST). Our goal was to describe real-world data in this population in the US in 2019 and prior years.

Methods

Endometrial Cancer Health Outcomes (ECHO) is a retrospective patient chart review study conducted in the US. Patients with non-MSI-H/pMMR aEC and progression between 06/01/2016–06/30/2019 FPST were eligible. Data collected included patient demographics, clinical and treatment characteristics, and clinical outcomes. Kaplan-Meier analyses were performed to estimate time to treatment discontinuation, real-world progression-free survival (rwPFS), and overall survival (OS), separately by treatment category.

Results

A total of 165 eligible patients initiated second-line therapy with chemotherapy ± bevacizumab (n = 140) or hormonal therapy (n = 25). Median age was 66.0 years at aEC diagnosis, 70.2% were Stage IIIB-IV, 40.0% had ECOG ≥ 2 at second-line therapy initiation. Median rwPFS was 5.0 months (95% CI: 4.0–6.0) for patients receiving chemotherapy ± bevacizumab and 5.5 months (95% CI: 3.0–29.0) for those receiving hormonal therapy. Median OS was 10.0 months (95% CI: 8.0–13.0) and 9.0 months (95% CI: 6.0-NA) in these groups, respectively.

Conclusions

Non-MSI-H/pMMR patients who initiated second-line therapy with chemotherapy ± bevacizumab or hormonal therapy had poor clinical outcomes with a median survival less than 1 year and rwPFS less than 6 months. This was the first study to define the clinical unmet need in patients with non-MSI-H/pMMR aEC with conventional therapy.

Implementing universal upfront multi-gene panel testing in endometrial cancer: From cost to practical considerations

OBJECTIVES

The routine use of upfront universal germline genetic testing among patients with newly diagnosed endometrial cancer (EC) has been proposed to improve diagnosis of Lynch syndrome (LS) and discover pathogenic variants (PVs) in other cancer susceptibility genes. We propose an algorithm prioritizing upfront multi-gene panel testing (MGPT) for newly diagnosed EC patients.

METHODS

A decision analysis compared the cost of the current algorithm of universal mismatch repair (MMR) immunohistochemistry (IHC) for all EC cases to a new MGPT algorithm that employs upfront MGPT for all EC cases and reserves MMR IHC for the recurrent setting. The increase in the number of LS diagnoses using upfront MGPT, and the number of patients with PVs in BRCA1 and BRCA2 are also estimated.

RESULTS

The MGPT algorithm demonstrated a cost savings of $259 per patient. Assuming 66,950 new cases of EC per year, this would represent $17.1 M of cost savings per year. When applied to all new diagnoses of EC in one year, the MGPT algorithm identified 660 (1%) additional cases of LS that would have been missed with the current algorithm. An additional 660 (1%) EC patients with BRCA1 or BRCA2 PVs would be diagnosed only through implementation of universal MGPT.

CONCLUSIONS

The use of universal upfront MGPT is a practical consideration for patients with newly diagnosed EC for cost savings and improved diagnosis of highly penetrant cancer syndromes. Incorporation of germline genetic testing in the upfront setting represents an opportunity to improve access to genetic counseling and testing, and ultimately an avenue to achieve equity and improve the lives of our patients with EC and their families.

MutL homolog 1 germline mutation c.(453+1_454-1)_(545+1_546-1)del identified in lynch syndrome: A case report and review of literature

BACKGROUND

Lynch syndrome (LS) is an autosomal dominant hereditary disorder because of germline mutations in DNA mismatch repair genes, such as MutL homolog 1 (MLH1), PMS1 homolog 2, MutS homolog 2, and MutS homolog 6. Gene mutations could make individuals and their families more susceptible to experiencing various malignant tumors. In Chinese, MLH1 germline mutation c.(453+1_454-1)_(545+1_546-1)del-related LS has been infrequently reported. Therefore, we report a rare LS patient with colorectal and endometrioid adenocarcinoma and describe her pedigree characteristics.

CASE SUMMARY

A 57-year-old female patient complained of irregular postmenopausal vaginal bleeding for 6 mo. She was diagnosed with LS, colonic malignancy, endometrioid adenocarcinoma, secondary fallopian tube malignancy, and intermyometrial leiomyomas. Then, she was treated by abdominal hysterectomy, bilateral oviduct oophorectomy, and sentinel lymph node resection. Genetic testing was performed using next-generation sequencing technology to detect the causative genetic mutations. Moreover, all her family members were offered a free genetic test, but no one accepted it.

CONCLUSION

No tumor relapse or metastasis was found in the patient during the 30-mo follow-up period. The genetic panel sequencing showed a novel pathogenic germline mutation in MLH1, c.(453+1_454-1)_(545+1_546-1)del, for LS. Moreover, cancer genetic counseling and testing are still in the initial development state in China, and maybe face numerous challenges in the further.

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.

Endometrial Cancer Management in Young Women

Endometrial cancer (EC) rarely develops in young women. Most cases are associated with known risk factors: BMI > 30, history of Polycystic Ovary Syndrome (PCOs), and race differentiation. The molecular EC classification based on The Cancer Genome Atlas Research Network divides these heterogeneous cancers into four types: Polymerase Epsilon Mutation (POLE), Microsatellite Instability (MSI), Copy Number Low (CNL), and Copy Number High (CNH). This division was introduced to allow for early assessment of neoplastic changes and clinical management, including targeted therapies. The basic technique for imaging endometrium changes is transvaginal sonography. Hysteroscopy is the standard for obtaining endometrial material for histological evaluation. The MRI result permits assessment of the extent of EC cancer infiltration. In young women who want to preserve fertility, apart from surgery, conservative management is often implemented after strict selection based on clinical and pathological data. This pharmacological treatment involves the administration of progestogens MPA (medroxyprogesterone acetate) and MA (megestrol acetate). The use of metformin may increase the effectiveness of such treatment. An alternative option is to apply progestogens locally—via the levonorgestrel-releasing intrauterine device. In addition to pharmacological treatment, hysteroscopic resection may be used—part of the uterine muscle adjacent to the pathologically changed endometrium may also undergo resection. An alternative is the administration of estrogen receptor modulators (e.g., SERMs) or aromatase inhibitors, or GnRH agonists.

Testing for Lynch Syndrome in Endometrial Carcinoma: From Universal to Age-Selective MLH1 Methylation Analysis

International guidelines recommend universal screening of endometrial carcinoma (EC) patients for Lynch syndrome (LS). This screening is generally based on mismatch repair (MMR) protein immunohistochemistry followed by MLH1 methylation analysis of MLH1-negative cases to exclude the likely sporadic cases from germline testing. As LS-associated EC is uncommon in the elderly, age-selective methylation testing could improve cost-efficiency. We performed MMR immunohistochemistry on 821 unselected ECs (clinic-based cohort) followed by a MLH1 promoter methylation test of all MLH1/PMS2-negative tumors. Non-methylated MLH1-deficient cases underwent NGS and MLPA-based germline analyses to identify MLH1 mutation carriers. A reduction in the test burden and corresponding false negative rates for LS screening were investigated for various age cut-offs. In addition, the age distribution of 132 MLH1 mutation carriers diagnosed with EC (registry-based cohort) was examined. A germline MLH1 mutation was found in 2/14 patients with non-methylated MLH1-deficient EC. When compared to a universal methylation analysis, selective testing with a cut-off age of 65 years, would have reduced the testing effort by 70.7% with a false negative rate for LS detection of 0% and 3% in the clinic and registry-based cohorts, respectively. The use of age-selective methylation analysis is a feasible way of reducing the costs and laboratory burden in LS screening for EC patients.

Patient-derived xenograft models capture genomic heterogeneity in endometrial cancer

Background

Endometrial cancer (EC) is a major gynecological cancer with increasing incidence. It comprises four molecular subtypes with differing etiology, prognoses, and responses to chemotherapy. In the future, clinical trials testing new single agents or combination therapies will be targeted to the molecular subtype most likely to respond. As pre-clinical models that faithfully represent the molecular subtypes of EC are urgently needed, we sought to develop and characterize a panel of novel EC patient-derived xenograft (PDX) models.

Methods

Here, we report whole exome or whole genome sequencing of 11 PDX models and their matched primary tumor. Analysis of multiple PDX lineages and passages was performed to study tumor heterogeneity across lineages and/or passages. Based on recent reports of frequent defects in the homologous recombination (HR) pathway in EC, we assessed mutational signatures and HR deficiency scores and correlated these with in vivo responses to the PARP inhibitor (PARPi) talazoparib in six PDXs representing the copy number high/p53-mutant and mismatch-repair deficient molecular subtypes of EC.

Results

PDX models were successfully generated from grade 2/3 tumors, including three uterine carcinosarcomas. The models showed similar histomorphology to the primary tumors and represented all four molecular subtypes of EC, including five mismatch-repair deficient models. The different PDX lineages showed a wide range of inter-tumor and intra-tumor heterogeneity. However, for most PDX models, one arm recapitulated the molecular landscape of the primary tumor without major genomic drift. An in vivo response to talazoparib was detected in four copy number high models. Two models (carcinosarcomas) showed a response consistent with stable disease and two models (one copy number high serous EC and another carcinosarcoma) showed significant tumor growth inhibition, albeit one consistent with progressive disease; however, all lacked the HR deficiency genomic signature.

Conclusions

EC PDX models represent the four molecular subtypes of disease and can capture intra-tumor heterogeneity of the original primary tumor. PDXs of the copy number high molecular subtype showed sensitivity to PARPi; however, deeper and more durable responses will likely require combination of PARPi with other agents.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-021-00990-z.

Identification of Lynch Syndrome

Lynch syndrome (LS) is an autosomal dominant hereditary cancer syndrome caused by pathogenic germline variants (PGV) in any of the 4 DNA mismatch repair (MMR) genes, MLH1, MSH2, MSH6, and PMS2, or deletions in EPCAM. LS leads to an increased risk of intestinal and extraintestinal cancers, of which colorectal and endometrial cancers are the most common. Individuals at risk for LS can be identified by using clinical criteria, prediction models, and universal tumor testing. Understanding each of these tools, including limitations and mimics of LS, is essential to the early identification of at-risk individuals.

Detection of MSH2 Gene Methylation in Extramammary Paget's Disease by Methylation-Sensitive High-Resolution Melting Analysis

Background

Extramammary Paget's disease (EMPD) is a rare skin tumor. Hypermethylation in the MSH2 promoter resulting in the downregulation of its protein expression shows a high detection rate in EMPD tumor tissue, which indicates that the methylation of MSH2 may play an important role in the pathogenesis of EMPD.

Objective

This study aims to establish a rapid analysis strategy based on the methylation-sensitive high-resolution melting curve (MS-HRM) to detect the methylation level of the MSH2 promoter.

Methods

With the use of universal methylated human DNA products, we established the MS-HRM standard curve to quantitatively detect the methylation level of the MSH2 promoter. Then, all 57 EMPD tumor DNA samples were analyzed. Pyrosequencing assay was also carried out to test the accuracy and efficacy of MS-HRM. Besides, a total of 54 human normal and other cancerous tissues were included in this study to test the reliability and versatility of the MS-HRM standard curve.

Results

In this study, by using the established MS-HRM, we found that 96.5% (55/57) EMPD tumor samples had varying methylation levels in the MSH2 promoter ranging from 0% to 30%. Then, the methylation data were compared to the results obtained from pyrosequencing, which showed a high correlation between these two techniques by Pearson's correlation (r = 0.9425) and Bland–Altman plots (mean difference = −0.1069) indicating that the methylation levels analyzed by MS-HRM were consistent with DNA pyrosequencing. Furthermore, in 23 normal and 31 other cancerous tissue samples, there were two colorectal cancer (CRC) tissues that tested MSH2 methylation positive (1% and 5%) which confirmed that our established MS-HRM can be widely applied to various types of samples.

Conclusion

MS-HRM standard curve can be used for the detection of the methylation level of MSH2 in EMPD tumor samples and other cancerous tissues potentially, which presents a promising candidate as a quantitative assay to analyze MSH2 promoter methylation in routine pathological procedure.

Clinical and pathological analysis of companion diagnostic testing of microsatellite instability-high for pembrolizumab in gynaecologic malignancy

BACKGROUND

Microsatellite instability-high is a known biomarker for anti-PD-1/PD-L1 immune checkpoint therapy. It is also a known tumour feature of Lynch syndrome, detected most frequently in endometrial cancer. However, it remains unclear how microsatellite instability testing is carried out in the clinical field.

METHODS

Ninety-nine patients with gynaecological malignant tumours who underwent microsatellite instability testing as a companion diagnosis for pembrolizumab and 16 patients who previously underwent microsatellite instability testing as a screening for Lynch syndrome were recruited. Clinical information, microsatellite instability status, outcomes, genetic assessments and information about cancer tissue were retrospectively analysed.

RESULTS

Ninety-nine patients had 101 gynaecologic malignant tumours including 26 endometrial, 38 ovarian and 28 cervical cancers, 9 with other tumours including 2 synchronous endometrial and ovarian cancers. All tissue samples were successfully tested, even though some were ≥10-year-old samples. Three cases (3.0%, 3/99) showed microsatellite instability-high; all cases were endometrial cancers with one case of synchronous endometrial and ovarian cancer [11.5% (3/26) in endometrial cancer, 2.6% (1/38) in ovarian cancer], and there was no microsatellite instability-high in cervical and other cancers. One of the endometrial cancer patients received pembrolizumab treatment, but finally died of cancer. Two other cases underwent genetic testing; both were diagnosed as Lynch syndrome. Six cases (37.5%) showed microsatellite instability-high in screening for Lynch syndrome.

CONCLUSIONS

Microsatellite instability-high was less commonly detected as a companion diagnosis for pembrolizumab in unselected gynaecologic patients. Genetic counselling should be always provided along with treatment selection.

CDKN2B-AS1 Promotes Malignancy as a Novel Prognosis-Related Molecular Marker in the Endometrial Cancer Immune Microenvironment

The prognosis of patients with endometrial cancer (EC) is closely associated with immune cell infiltration. Although abnormal long non-coding RNA (lncRNA) expression is also linked to poor prognosis in patients with EC, the function and action mechanism of immune infiltration-related lncRNAs underlying the occurrence and development of EC remains unclear. In this study, we analyzed lncRNA expression using The Cancer Genome Atlas and clinical data and identified six lncRNAs as prognostic markers for EC, all of which are associated with the infiltration of immune cell subtypes, as illustrated by ImmLnc database and ssGSEA analysis. Real-time quantitative polymerase chain reaction showed that CDKN2B-AS1 was significantly overexpressed in EC, whereas its knockdown inhibited the proliferation and invasion of EC cells and the in vivo growth of transplanted tumors in nude mice. Finally, we constructed a competing endogenous RNA regulatory network and conducted Gene Ontology enrichment analysis to elucidate the potential molecular mechanism underlying CDKN2B-AS1 function. Overall, we identified molecular targets associated with immune infiltration and prognosis and provide new insights into the development of molecular therapies and treatment strategies against EC.

Up-Front Multigene Panel Testing for Cancer Susceptibility in Patients With Newly Diagnosed Endometrial Cancer: A Multicenter Prospective Study

PURPOSE

Clinical utility of up-front multigene panel testing (MGPT) is directly related to the frequency of pathogenic variants (PVs) in the population screened and how genetic findings can be used to guide treatment decision making and cancer prevention efforts. The benefit of MGPT for many common malignancies remains to be determined. In this study, we evaluated up-front MGPT in unselected patients with endometrial cancer (EC) to determine the frequency of PVs in cancer susceptibility genes.

METHODS

Patients with EC were prospectively enrolled at nine Ohio institutions from October 1, 2017, to December 31, 2020. Nine hundred and sixty-one patients with newly diagnosed EC underwent clinical germline MGPT for 47 cancer susceptibility genes. In addition to estimating the prevalence of germline PVs, the number of individuals identified with Lynch syndrome (LS) was compared between MGPT and tumor-based screening.

RESULTS

Likely pathogenic variants or PVs were identified in 97 of 961 women (10.1%). LS was diagnosed in 29 of 961 patients (3%; 95% CI, 2.1 to 4.3), with PVs in PMS2 most frequent. MGPT revealed nine patients with LS in addition to the 20 identified through routine tumor-based screening. BRCA1 and BRCA2 PVs were found in 1% (10 of 961; 95% CI, 0.6 to 1.9) of patients and that group was significantly enriched for type II ECs.

CONCLUSION

This prospective, multicenter study revealed potentially actionable germline variants in 10% of unselected women with newly diagnosed EC, supporting the use of up-front MGPT for all EC patients. The discovery that BRCA1 or BRCA2 heterozygotes frequently had type II cancers points to therapeutic opportunities for women with aggressive histologic EC subtypes.

MiR-137 Targets the 3' Untranslated Region of MSH2: Potential Implications in Lynch Syndrome-Related Colorectal Cancer

Mismatch Repair (MMR) gene dysregulation plays a fundamental role in Lynch Syndrome (LS) pathogenesis, a form of hereditary colorectal cancer. Loss or overexpression of key MMR genes leads to genome instability and tumorigenesis; however, the mechanisms controlling MMR gene expression are unknown. One such gene, MSH2, exerts an important role, not only in MMR, but also in cell proliferation, apoptosis, and cell cycle control. In this study, we explored the functions and underlying molecular mechanisms of increased MSH2 expression related to a c.*226A>G variant in the 3'untranslated (UTR) region of MSH2 that had been previously identified in a subject clinically suspected of LS. Bioinformatics identified a putative binding site for miR-137 in this region. To verify miRNA targeting specificity, we performed luciferase gene reporter assays using a MSH2 3'UTR psiCHECK-2 vector in human SW480 cells over-expressing miR-137, which showed a drastic reduction in luciferase activity (p > 0.0001). This effect was abolished by site-directed mutagenesis of the putative miR-137 seed site. Moreover, in these cells we observed that miR-137 levels were inversely correlated with MSH2 expression levels. These results were confirmed by results in normal and tumoral tissues from the patient carrying the 3'UTR c.*226A>G variant in MSH2. Finally, miR-137 overexpression in SW480 cells significantly suppressed cell proliferation in a time- and dose-dependent manner (p < 0.0001), supporting a role for MSH2 in apoptosis and cell proliferation processes. Our findings suggest miR-137 helps control MSH2 expression via its 3'UTR and that dysregulation of this mechanism appears to promote tumorigenesis in colon cells.

Endometrial cancer in Lynch syndrome

Lynch syndrome (LS) is an autosomal dominant inherited disease caused by germline pathogenic variants (PVs) in mismatch repair (MMR) genes. LS-associated endometrial cancer (LS-EC) is the most common extraintestinal sentinel cancer caused by germline PVs in MMR genes, including MLH1, MSH2, MSH6 and PMS2. The clinicopathologic features of LS-EC include early age of onset, lower body mass index (BMI), endometrioid carcinoma and lower uterine segment involvement. There has been significant progress in screening, diagnosis, surveillance, prevention and treatment of LS-EC. Many studies support universal screening for LS among patients with EC. Screening mainly involves a combination of traditional clinical criteria and molecular techniques, including MMR-immunohistochemistry (MMR-IHC), microsatellite instability (MSI) testing, MLH1 promoter methylation testing and gene sequencing. The effectiveness of endometrial biopsy and transvaginal ultrasound (TVS) for clinical monitoring of asymptomatic women with LS are uncertain yet. Preventive strategies include hysterectomy and bilateral salpingo-oophorectomy (BSO) as well as chemoprophylaxis using exogenous progestin or aspirin. Recent research has revealed the benefits of immunotherapy for LS-EC. The NCCN guidelines recommend pembrolizumab and nivolumab for treating patients with advanced or recurrent microsatellite instability-high (MSI-H)/mismatch repair-deficient (dMMR) EC.

Genomic alterations in gynecological malignancies: histotype-associated driver mutations, molecular subtyping schemes, and tumorigenic mechanisms

There are numerous histological subtypes (histotypes) of gynecological malignancies, with each histotype considered to largely reflect a feature of the "cell of origin," and to be tightly linked with the clinical behavior and biological phenotype of the tumor. The recent advances in massive parallel sequencing technologies have provided a more complete picture of the range of the genomic alterations that can persist within individual tumors, and have highlighted the types and frequencies of driver-gene mutations and molecular subtypes often associated with these histotypes. Several large-scale genomic cohorts, including the Cancer Genome Atlas (TCGA), have been used to characterize the genomic features of a range of gynecological malignancies, including high-grade serous ovarian carcinoma, uterine corpus endometrial carcinoma, uterine cervical carcinoma, and uterine carcinosarcoma. These datasets have also been pivotal in identifying clinically relevant molecular targets and biomarkers, and in the construction of molecular subtyping schemes. In addition, the recent widespread use of clinical sequencing for the more ubiquitous types of gynecological cancer has manifested in a series of large genomic datasets that have allowed the characterization of the genomes, driver mutations, and histotypes of even rare cancer types, with sufficient statistical power. Here, we review the field of gynecological cancer, and seek to describe the genomic features by histotype. We also will demonstrate how these are linked with clinicopathological attributes and highlight the potential tumorigenic mechanisms.

A Durable Response to Pembrolizumab in a Patient with Uterine Serous Carcinoma and Lynch Syndrome due to the MSH6 Germline Mutation

Pembrolizumab, a programmed death 1 ligand (PD-1) checkpoint inhibitor, has elicited responses in mismatch repair (MMR)-deficient advanced solid tumors, leading to its agnostic approval by the US Food and Drug Administration in 2017 when no other therapeutic options are available. However, there are still insufficient data on the response to checkpoint inhibitors in advanced endometrial cancer related to Lynch syndrome (LS) and, specifically, in uterine serous carcinoma, which is uncommon in LS. Here we report a case of metastatic uterine serous carcinoma due to a germline MSH6 mutation (Lynch syndrome) that was discovered because of a patient's tumor MMR deficiency. The patient was started on first-line pembrolizumab in 2018 and sustained a partial response. She remains asymptomatic and progression free for more than 2 years. Tumor sequencing showed a high mutational burden and an upstream somatic mutation in the same gene, p.F1088fs. Immunohistochemical staining was negative for PD-L1 expression. We discuss clinical characteristics of the patient, molecular features of her tumor, and the mechanism of her tumor response. We also discuss the duration of immunotherapy in her case. Our case demonstrated a partial response and a long-term remission from the frontline single-agent pembrolizumab in a woman with metastatic uterine serous carcinoma and Lynch syndrome due to a germline MSH6 gene mutation. Our experience suggests a potential significant clinical benefit of checkpoint inhibitors used as single agents early on in the treatment of MMR-deficient/high microsatellite instability/hypermutated uterine cancers in women with Lynch syndrome. KEY POINTS: Even though checkpoint inhibitors are effective in mismatch repair-deficient endometrial cancer, it is unknown whether the response to them differs between women with endometrial cancer due to germline mutations in a mismatch repair gene (Lynch syndrome) and women with sporadic endometrial cancer. In our case, a patient with Lynch syndrome and recurrent mismatch repair-deficient serous endometrial cancer achieved a durable remission on the first-line therapy with the checkpoint inhibitor pembrolizumab and remains progression free after more than 2 years. Based on our observation and the data, suggesting the stronger immune activation in women with Lynch syndrome-associated endometrial cancer, we propose to use checkpoint inhibitor monotherapy early in the course of their treatment and stratify patients for the presence of Lynch syndrome in clinical trials.

Practice patterns and results of tumor and germline genetic evaluation of women with endometrial cancer in south Louisiana

The objectives were to describe rates of MMRd or MSI-H EC tumors, the prevalence of LS, the practice patterns of EC genetic evaluation and adherence to NCCN guidelines, and to identify disparities in the genetic evaluation of women with EC. A retrospective cohort study was performed on women with EC from 1/2013 to 12/2019, and information collected included demographics, personal and family history, EC diagnosis and treatment, and details of genetic evaluation. Statistical analysis included a multivariable logistic regression to adjust for all covariate effects simultaneously and Fisher exact tests of independence and Wilcoxon rank-sum tests to compare categorical and continuous covariates, respectively. Of the 286 women with EC, 80 EC tumors were tested, and 27.5% were MMRd or MSI-H. Of the 21 women who had germline testing, no cases of LS were identified. Before the NCCN recommended universal tumor testing, 17.6% of women had tumor testing performed compared to 60.0% after February of 2017 (OR = 2.51, 95% CI 1.89-3.32). Advanced cancer stage was nearly associated with an increased likelihood of tumor testing (OR = 1.40, 95% CI 1.00-1.97). No disparities were identified. We described patterns of genetic evaluation and tumor testing results for women with EC in south Louisiana and found similar rates of MMRd or MSI-H EC tumors as previously reported in other populations. Rates of tumor testing increased after the NCCN recommendation for universal tumor testing, but it is critical to identify weaknesses in this process and develop an algorithm to improve care for women with EC.

Lynch syndrome associated endometrial carcinomas in Western Australia: an analysis of universal screening by mismatch repair protein immunohistochemistry

BACKGROUND

In 2016 universal screening with mismatch repair protein immunohistochemistry in all newly diagnosed endometrial carcinomas was introduced in Western Australia.

OBJECTIVE

To compare the prevalence of Lynch syndrome associated endometrial carcinomas between 2016 and 2019 with a historical control (2015). Additionally, to compare the number of cases appropriately referred for genetic assessment.

METHODS

A cross-sectional study of cases presented at the Western Australia gynecologic oncology tumor board was carried out. The primary outcome was the prevalence of Lynch syndrome associated endometrial carcinomas. A secondary outcome was the number of cases appropriately referred for genetic assessment. The following variables were extracted: date of birth; age at diagnosis; vital status; tumor mismatch repair protein expression status (retained or lost) and if lost, the specific mismatch repair protein deficiency; patients who were referred to a genetic clinic; and family history, if recorded. Data were collected from the clinical databases of the Familial Cancer Program at Genetic Services of Western Australia and WOMEN Center, to determine whether patients were appropriately referred for genetic evaluation and to ascertain the results of genetic testing.

RESULTS

Between 2016 and 2019, there were 1040 new endometrial carcinomas. Tumors of 883 (85%) patients underwent mismatch repair protein immunohistochemistry compared with 117 of 199 patients (59%) in 2015 (χ² 73.14, p<0.001). Of 883 tumors tested, 242 (27%) showed loss of mismatch repair protein expression. In 2015, 30 (26%) tumors of 117 tested showed loss of mismatch repair protein expression. During the 4 years of universal screening, 13 (1.5%) of 883 patients screened were diagnosed with Lynch syndrome compared with 2 (1.7%) of 117 in 2015 (Fisher's exact test 0.04, p=0.69). In 2015, 11 (37%) of 30 patients with loss of mismatch repair protein expression were not referred for genetic assessment compared with 36 (17%) of 209 patients in the universal screening group (χ² 6.28, p=0.02). No cases of Lynch syndrome were diagnosed in patients aged over 70 years.

CONCLUSIONS

Universal immunohistochemical screening did not increase the proportion of Lynch syndrome associated endometrial carcinomas identified, although the study was underpowered to detect small differences. There was an improvement in appropriate referrals for genetic assessment.

Modern day screening for Lynch syndrome in endometrial cancer: the KEM experience

PURPOSE

Current guidelines for Lynch syndrome detection in endometrial cancer (EC) patients rely either on risk evaluation, based on personal/family history, or detection of mismatch repair (MMR) deficiency on tumor tissue. We present a combined screening algorithm for Lynch syndrome.

METHODS

In this study, 213 consecutive patients treated for EC at Kliniken Essen-Mitte between 2014 and 2018 were included. Personal/family history was evaluated by the Amsterdam II, revised Bethesda/German-DKG criteria and prediction model PREMM₅. MMR testing was performed by immunohistochemistry (IHC) and/or polymerase chain reaction (PCR) based microsatellite analysis on tumor tissue. MLH1 promoter methylation analysis was performed in case of MLH1 loss or microsatellite instability.

RESULTS

Based on personal/family history 2/213 (Amsterdam II), 31/213 (revised Bethesda/German-DKG) and 149/213 (PREMM₅) patients were identified as at risk for Lynch syndrome. MMR analysis was performed by IHC in 51.2%, by PCR in 32.4%, and in 16.4% of patients both methods were used. MMR deficiency was detected in 20.6% (44/213). Methylation analysis was performed in 27 patients of whom, 22 (81.4%) showed MLH1 promoter hypermethylation. Only 9% of MMR deficient patients were identified as at risk for Lynch syndrome by the revised Bethesda/German-DKG criteria. A pathogenic germline mutation was discovered in 3 out of 20 patients that underwent genetic testing. None of these patients were younger than 50 years or had a family history of Lynch syndrome-associated malignancies.

CONCLUSION

General MMR assessment is a feasible strategy to improve the detection of Lynch Syndrome in patients with EC.

Diagnosis of Lynch Syndrome and Strategies to Distinguish Lynch-Related Tumors from Sporadic MSI/dMMR Tumors

Simple Summary

Microsatellite instability (MSI) is a hallmark of Lynch syndrome (LS)-related tumors but is not specific, as most of MSI/mismatch repair-deficient (dMMR) tumors are sporadic. Therefore, the identification of MSI/dMMR requires additional diagnostic tools to identify LS. In this review, we address the hallmarks of LS and present recent advances in diagnostic and screening strategies to identify LS patients. We also discuss the pitfalls associated with current strategies, which should be taken into account in order to improve the diagnosis of LS.

Abstract

Microsatellite instability (MSI) is a hallmark of Lynch syndrome (LS)-related tumors but is not specific to it, as approximately 80% of MSI/mismatch repair-deficient (dMMR) tumors are sporadic. Methods leading to the diagnosis of LS have considerably evolved in recent years and so have tumoral tests for LS screening and for the discrimination of LS-related to MSI-sporadic tumors. In this review, we address the hallmarks of LS, including the clinical, histopathological, and molecular features. We present recent advances in diagnostic and screening strategies to identify LS patients. We also discuss the pitfalls associated with the current strategies, which should be taken into account to improve the diagnosis of LS and avoid inappropriate clinical management.

How Should We Test for Lynch Syndrome? A Review of Current Guidelines and Future Strategies

International guidelines for the diagnosis of Lynch syndrome (LS) recommend molecular screening of colorectal cancers (CRCs) to identify patients for germline mismatch repair (MMR) gene testing. As our understanding of the LS phenotype and diagnostic technologies have advanced, there is a need to review these guidelines and new screening opportunities. We discuss the barriers to implementation of current guidelines, as well as guideline limitations, and highlight new technologies and knowledge that may address these. We also discuss alternative screening strategies to increase the rate of LS diagnoses. In particular, the focus of current guidance on CRCs means that approximately half of Lynch-spectrum tumours occurring in unknown male LS carriers, and only one-third in female LS carriers, will trigger testing for LS. There is increasing pressure to expand guidelines to include molecular screening of endometrial cancers, the most frequent cancer in female LS carriers. Furthermore, we collate the evidence to support MMR deficiency testing of other Lynch-spectrum tumours to screen for LS. However, a reliance on tumour tissue limits preoperative testing and, therefore, diagnosis prior to malignancy. The recent successes of functional assays to detect microsatellite instability or MMR deficiency in non-neoplastic tissues suggest that future diagnostic pipelines could become independent of tumour tissue.

Advances in genetic technologies result in improved diagnosis of mismatch repair deficiency in colorectal and endometrial cancers

Background

Testing cancers for mismatch repair deficiency (dMMR) by immunohistochemistry (IHC) is a quick and inexpensive means of triaging individuals for germline Lynch syndrome testing. The aim of this study was to evaluate tumour dMMR and the prevalence of Lynch syndrome in patients referred to the Manchester Centre for Genomic Medicine, which serves a population of 5.6 million.

Methods

Tumour testing used IHC for MMR proteins with targeted BRAF and MLH1 promotor methylation testing followed by germline mutation and somatic testing as appropriate.

Results

In total, 3694 index tumours were tested by IHC (2204 colorectal cancers (CRCs), 739 endometrial cancers (ECs) and 761 other), of which 672/3694 (18.2%) had protein loss, including 348 (9.4%) with MLH1 loss. MLH1 loss was significantly higher for 739 ECs (15%) vs 2204 CRCs (10%) (p=0.0003) and was explained entirely by higher rates of somatic MLH1 promoter hypermethylation (87% vs 41%, p<0.0001). Overall, 65/134 (48.5%) patients with MLH1 loss and no MLH1 hypermethylation or BRAF c.1799T>A had constitutional MLH1 pathogenic variants. Of 456 patients with tumours showing loss of MSH2/MSH6, 216 (47.3%) had germline pathogenic variants in either gene. Isolated PMS2 loss was most suggestive of a germline MMR variant in 19/26 (73%). Of those with no germline pathogenic variant, somatic testing identified likely causal variants in 34/48 (71%) with MLH1 loss and in MSH2/MSH6 in 40/47 (85%) with MSH2/MSH6 loss.

Conclusions

Reflex testing of EC/CRC leads to uncertain diagnoses in many individuals with dMMR following IHC but without germline pathogenic variants or MLH1 hypermethylation. Tumour mutation testing is effective at decreasing this by identifying somatic dMMR in >75% of cases.

Complete Loss of EPCAM Immunoexpression Identifies EPCAM Deletion Carriers in MSH2-Negative Colorectal Neoplasia

Simple Summary

Colorectal carcinomas from patients with Lynch syndrome (LS) due to EPCAM deletions show loss of MSH2 expression. The aim of our study was to evaluate the usefulness of EPCAM expression in identifying carriers of EPCAM deletion among patients with MSH2-negative lesions. MSH2 and EPCAM immunohistochemistry was performed in a large series of lesions (190) composed of malignant and benign neoplasms as well as precursor lesions of different organs from 71 patients with suspected LS due to MSH2 alterations. Germ-line analysis confirmed LS in 68 patients due to MSH2 mutations (53) and EPCAM deletions (15). Among colorectal lesions with lack of MSH2 expression, only 17 were EPCAM-negative and belonged to patients with EPCAM deletions. We confirm that loss of EPCAM expression identifies EPCAM deletion carriers with 100% specificity and we recommend adding EPCAM IHC to the algorithm of MSH2-negative colorectal neoplasia.

Abstract

The use of epithelial cell adhesion molecule (EPCAM) immunohistochemistry (IHC) is not included in the colorectal cancer (CRC) screening algorithm to detect Lynch syndrome (LS) patients. The aim of the present study was to demonstrate that EPCAM IHC is a useful tool to guide the LS germ-line analysis when a loss of MSH2 expression was present. We retrospectively studied MSH2 and EPCAM IHC in a large series of 190 lesions composed of malignant neoplasms (102), precursor lesions of gastrointestinal (71) and extra-gastrointestinal origin (9), and benign neoplasms (8) from different organs of 71 patients suspicious of being LS due to MSH2 alterations. LS was confirmed in 68 patients, 53 with MSH2 mutations and 15 with EPCAM 3′-end deletions. Tissue microarrays were constructed with human normal tissues and their malignant counterparts to assist in the evaluation of EPCAM staining. Among 154 MSH2-negative lesions, 17 were EPCAM-negative, including 10 CRC and 7 colorectal polyps, and 5 of them showed only isolated negative glands. All lesions showing a lack of EPCAM expression belonged to patients with EPCAM 3′-end deletions. EPCAM IHC is a useful screening tool, with 100% specificity to identify LS patients due to EPCAM 3′-end deletions in MSH2-negative CRC and MSH2-negative colorectal polyps.

Variation in physician-directed immunohistochemistry screening among women with endometrial cancer

Objective

Immunohistochemistry screening is a reliable method for identifying women with endometrial cancer who are at risk for Lynch syndrome, but clinical workflows used to implement immunohistochemistry screening protocols can vary by institution. The goal of this study was to investigate variation in performance of immunohistochemistry screening when a physician order is required.

Methods

Retrospective study from an integrated healthcare system with a risk-based immunohistochemistry screening policy for Lynch syndrome from January 2015 to December 2016. Immunohistochemistry screening was indicated for all women with endometrial cancer aged <60 years and women with endometrial cancer aged ≥60 years who had a personal/family history suggestive of Lynch syndrome. However, a physician order was needed to have immunohistochemistry screening performed on the tumor specimen as our health system did not have reflex screening in the clinical workflow. Demographics and tumor characteristics were reviewed, and patients were stratified by immunohistochemistry screening status. Multivariable regression was performed to identify factors associated with immunohistochemistry performance and reported as odds ratios (ORs) with 95% confidence intervals (CIs).

Results

There were 1399 eligible patients in the study. With a required physician order, immunohistochemistry screening rates (20% overall, 34% aged <60 years) were significantly lower than previous reports (36% overall, 90% aged <60 years, p≤0.0001 for both comparisons). Significant factors associated with immunohistochemistry screening performance identified by multivariable analysis included age, race, body mass index, personal/family cancer history, diabetes, endometrioid histology, and tumor grade. Asian women were most likely to have immunohistochemistry screening (OR 1.58, 95% CI 1.07 to 2.34) whereas black women were least likely (OR 0.43, 95% CI 0.22 to 0.91).

Conclusions

Immunohistochemistry screening rates in women with endometrial cancer were lower in our health system compared with prior reports in the literature, and there were variations in screening performance according to patient age, race, and body mass index. Requiring a physician order for immunohistochemistry screening likely creates a barrier in screening uptake, therefore automated immunohistochemistry screening is recommended.

Clinicopathological significance of deficient DNA mismatch repair and MLH1 promoter methylation in endometrioid endometrial carcinoma

The pathogenesis of DNA mismatch repair (MMR)-deficient endometrial carcinoma (EC) is driven by inactivating methylation or less frequently mutation of an MMR gene (MLH1, PMS2, MSH2, or MSH6). This study evaluated the prognostic and clinicopathologic differences between methylation-linked and nonmethylated MMR-deficient endometrioid ECs. We performed MMR immunohistochemistry and methylation-specific multiplex ligation-dependent probe amplification, and classified 682 unselected endometrioid ECs as MMR proficient (MMRp, n = 438) and MMR deficient (MMRd, n = 244), with the latter subcategorized as methylated (MMRd Met) and nonmethylated tumors. Loss of MMR protein expression was detected in 35.8% of the tumors as follows: MLH1 + PMS2 in 29.8%, PMS2 in 0.9%, MSH2 + MSH6 in 1.3%, MSH6 in 2.8%, and multiple abnormalities in 0.9%. Of the 244 MMRd cases, 76% were methylation-linked. MMR deficiency was associated with older age, high grade of differentiation (G3), advanced stage (II-IV), larger tumor size, abundant tumor-infiltrating lymphocytes, PD-L1 positivity in immune cells and combined positive score, wild-type p53, negative L1CAM, ARID1A loss, and type of adjuvant therapy. MMRd-Met phenotype correlated with older age and larger tumor size, and predicted diminished disease-specific survival in the whole cohort. In the MMRd subgroup, univariate analysis demonstrated an association between disease-specific survival and disease stage II-IV, high grade (G3), deep myometrial invasion, lymphovascular invasion, ER negativity, and L1CAM positivity. In conclusion, MMR methylation profile correlates with clinicopathologic characteristics of endometrioid EC, and MMRd-Met phenotype predicts lower disease-specific survival. MMR deficiency, but not MLH1 methylation status, correlates with T-cell inflammation and PD-L1 expression.

Clinicopathologic features of endometrial cancer with mismatch repair deficiency

The inclusion of DNA mismatch repair (MMR) evaluation as a standard of care for endometrial cancer management will result in a growing population of patients with MMR deficiency and negative germline Lynch syndrome testing (MMR-deficient). In this systematic review and study, the clinicopathologic features of endometrial cancer in patients with MMR-intact, MLH1 methylation positive, MMR-deficient or Lynch syndrome are evaluated. A systematic search of online databases between 1990 and 2018 identified studies of endometrial cancer patients with tumour testing (MMR protein immunohistochemistry or microsatellite instability) and germline assessment for Lynch syndrome. Extracted data included tumour testing, germline genetic testing, age, body mass index (BMI), family history, tumour stage, grade and histologic type. Associations between MMR-intact, MLH1 methylation positive, MMR-deficient and Lynch syndrome groups were analysed using descriptive statistics. The comprehensive search produced 4,400 publications, 29 met inclusion criteria. A total of 7,057 endometrial cancer cases were identified, 1,612 with abnormal immunohistochemistry, 977 with microsatellite instability. Nine-hundred patients underwent germline genetic testing, identifying 212 patients with Lynch syndrome. Patients in the Lynch syndrome and MMR-deficient groups were significantly younger than patients in the MMR-intact and MLH1 methylation positive groups. Patients with MMR-intact tumours had the highest BMI, followed by MMR-deficient, then Lynch syndrome. MMR-intact tumours were more likely to be grade I at diagnosis than other groups. Patients with Lynch syndrome and MMR-deficient tumours were less likely to have stage I disease as compared to patients with MMR-intact tumours. Endometrial cancer patients with MMR-deficient tumours have similar features to those with germline Lynch syndrome mutations, including age, grade, histology and stage. Even in the absence of a germline mutation, tumour evaluation for MMR status may have important clinical implications.

Understanding implementation success: protocol for an in-depth, mixed-methods process evaluation of a cluster randomised controlled trial testing methods to improve detection of Lynch syndrome in Australian hospitals

INTRODUCTION

In multisite intervention trials, implementation success often varies widely across settings. Process evaluations are crucial to interpreting trial outcomes and understanding contextual factors and causal chains necessary for successful implementation. Lynch syndrome is a hereditary cancer predisposition conferring an increased risk of colorectal, endometrial and other cancer types. Despite systematic screening protocols to identify Lynch syndrome, the condition remains largely underdiagnosed. The Hide and Seek Project ('HaSP') is a cluster randomised controlled trial determining the effectiveness of two approaches to improving Lynch syndrome detection at eight Australian hospital networks. To enhance widespread implementation of optimal Lynch syndrome identification, there is a need to understand not only what works, but also why, in what contexts, and at what costs. Here we describe an in-depth investigation of factors influencing successful implementation of procedures evaluated in the HaSP trial.

METHODS AND ANALYSIS

A mixed-methods, theory-driven process evaluation will be undertaken in parallel to the HaSP trial. Data will include: interviews of Implementation Leads and Lynch syndrome stakeholders, pre-post implementation questionnaires, audio analysis of meetings and focus groups, observation of multidisciplinary team meetings, fidelity checklists and project log analysis. Results will be triangulated and coded, drawing on the Theoretical Domains Framework, Consolidated Framework for Implementation Research and Proctor's implementation outcomes.

ETHICS AND DISSEMINATION

Use of a theory-based process evaluation will enhance interpretation and generalisability of HaSP trial findings, and contribute to the implementation research field by furthering understanding of the conditions necessary for implementation success. Ethical approval has been granted and results will be disseminated via publications in peer-reviewed journals and conference presentations. At trial completion, key findings will be fed back to sites to enable refinement of intervention strategies, both in the context of Lynch syndrome and for the possible generalisability of intervention components in other genetic and broader clinical specialties.

HASP TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (Identifier: ACTRN12618001072202). Registered 27 June 2018. http://www.ANZCTR.org.au/ACTRN12618001072202.aspx.

PMS2 germline mutation c.1577delA (p.Asp526Alafs*69)-induced Lynch syndrome-associated endometrial cancer: A case report

RATIONALE

Lynch syndrome (LS) is an autosomal dominant cancer predisposition condition caused by germline heterozygous mutations in mismatch repair (MMR) genes. However, as one of the MMR genes, PMS2 mutation-induced LS-associated endometrial cancer (LSAEC) was rarely reported.

PATIENT CONCERNS

A 26-year-old female patient suffered from prolonged menstrual period and increased menstrual flow for 2 months.

DIAGNOSES

The patient was diagnosed with cervix CIN III, endometrial cancer (EC), anemia, and LS.

INTERVENTIONS

Total hysterectomy, bilateral salpingectomy, pelvic lymphadenectomy were performed for treating EC, while ovariectomy was refused by the patient. The patient underwent postoperative chemotherapy with paclitaxel combined with carboplatin for 6 courses of treatment. Laparoscopic partial enterectomy was applied for treating colon cancer 5 years later after the surgery treatment for EC. Besides, Sanger sequencing and high-throughput genome sequencing were employed to detect the genetic status of the family that included two generations with four members. Immunohistochemistry (IHC) staining was used to identify the function of PMS2 mutation.

OUTCOMES

The 26-year-old Chinese patient suffered from LSAEC and recovered well after surgery. A PMS2 germline heterozygous mutation (c.1577delA) was confirmed by gene sequencing 5 years later. In addition, PMS2 mutation was verified by IHC. The patient was followed up for 7 years.

LESSONS

Carrying PMS2 germline mutation (c.1577delA) confers an extremely high susceptibility of suffering from LS-associated cancers. Thus, close clinical monitoring and prophylactic surgery are highly recommended to reduce the morbidity and mortality of LS-associated cancers.