Risk of colorectal and endometrial cancers in EPCAM deletion-positive Lynch syndrome: a cohort study

Deficient Mismatch Repair and Microsatellite Instability in Solid Tumors

The integrity of the genome is maintained by mismatch repair (MMR) proteins that recognize and repair base mismatches and insertion/deletion errors generated during DNA replication and recombination. A defective MMR system results in genome-wide instability and the progressive accumulation of mutations. Tumors exhibiting deficient MMR (dMMR) and/or high levels of microsatellite instability (termed "microsatellite instability high", or MSI-H) have been shown to possess fundamental differences in clinical, pathological, and molecular characteristics, distinguishing them from their "microsatellite stable" (MSS) counterparts. Molecularly, they are defined by a high mutational burden, genetic instability, and a distinctive immune profile. Their distinct genetic and immunological profiles have made dMMR/MSI-H tumors particularly amenable to treatment with immune checkpoint inhibitors (ICIs). The ongoing development of biomarker-driven therapies and the evaluation of novel combinations of immune-based therapies, with or without the use of conventional cytotoxic treatment regimens, continue to refine treatment strategies with the goals of maximizing therapeutic efficacy and survival outcomes in this distinct patient population. Moreover, the resultant knowledge of the mechanisms by which these features are suspected to render these tumors more responsive, overall, to immunotherapy may provide information regarding the potential optimization of this therapeutic approach in tumors with proficient MMR (pMMR)/MSS tumors.

Mismatch Repair Proficient Colorectal Adenocarcinoma in Two Patients With Lynch Syndrome

Screening for Lynch syndrome (LS) is essential in colorectal carcinoma (CRC) diagnosis. The hallmark of CRC in LS is mismatch repair (MMR) deficiency, a vital biomarkers assessed by microsatellite instability (MSI) analysis and/or immunohistochemistry (IHC) staining of the MMR proteins in the tumor, that also predict response to immune checkpoint inhibitors. We report two LS patients who developed MMR proficient CRCs. Patient A, with a pathogenic MSH6 germline variant, presented with two MMR discordant CRCs: a rectal MMRd/MSI adenocarcinoma, and a sigmoid MMR proficient (MMRp) and microsatellite stable (MSS) adenocarcinoma, leading to metastasis. While the MMRd/MSI carcinoma was recognized early and showed complete pathologic response after pembrolizumab treatment, the MMRp/MSS adenocarcinoma was underrecognized and poorly responsive to treatment. A second patient, with a pathogenic PMS2 variant, also developed a MMRp CRC. These cases highlight the complex biological pathways in CRC development and the impact of molecular classification on treatment.

Constitutional Epimutations: From Rare Events Toward Major Cancer Risk Factors?

Constitutional epimutations are epigenetic aberrations that arise in normal cells prenatally. Two major forms exist: secondary constitutional epimutations (SCEs), associated with cis-acting genetic aberrations, and primary constitutional epimutations (PCEs), for which no associated genetic aberrations were identified. Some SCEs have been associated with risk of cancer (MLH1 and MSH2 with colon or endometrial cancers, BRCA1 with familial breast and ovarian cancers), although such epimutations are rare, with a total of <100 cases reported. This contrasts recent findings for PCE, where low-level mosaic BRCA1 epimutations are recorded in 5%-10% of healthy females across all age groups, including newborns. BRCA1 PCEs predict an elevated risk of high-grade serous ovarian cancer and triple-negative breast cancer (TNBC) and are estimated to account for about 20% of all TNBCs. A similarly high population frequency is observed for mosaic constitutional epimutations in MGMT, occurring as PCE or SCE, but not in MLH1. Contrasting BRCA1 and MLH1, a potential association with cancer risk for MGMT epimutations is yet unclear. In this review, we provide a summary of findings linking constitutional epimutations to cancer risk with emphasis on PCE. We also highlight challenges in detection of PCE exemplified by low-level mosaic epimutations in BRCA1 and indicate the need for further studies, hypothesizing that improved knowledge about PCE may add significantly to our understanding of cancer risk, carcinogenesis, and potentially development of other diseases as well.

Lynch Syndrome-Impact of the Type of Deficient Mismatch Repair Gene Mutation on Diagnosis, Clinical Presentation, Surveillance and Therapeutic Approaches

In today's world, with its continuing advancements in genetics, the identification of Lynch syndrome (LS) increasingly relies on sophisticated genetic testing techniques. Most guidelines recommend a tailored surveillance program, as well as personalized prophylactic and therapeutic approaches, according to the type of dMMR gene mutation. Carriers of path_MLH1 and path_MSH2 genes have a higher risk of developing colorectal cancer (CRC), despite intensive colonoscopic surveillance. Conversely, carriers of path_MSH6 and path_PMS2 genes have a lower risk of developing CRC, which may be due to their lower penetrance and later age of onset. Thus, carriers of path_MLH1 or path_MSH2 would theoretically derive greater benefits from total colectomy, compared to low-risk carriers (path_MSH6 and path_PMS2), in which colonoscopic surveillance might achieve an efficient prophylaxis. Furthermore, regarding the risk of endometrial/ovarian cancer development, there is a global agreement to offer both hysterectomy and bilateral salpingo-oophorectomy to path_MLH1, path_MSH2 and path_MSH6 carriers after the age of 40. In patients with CRC, preoperative knowledge of the diagnosis of LS is of tremendous importance, due to the high risk of metachronous CRC. However, this risk depends on the type of dMMR gene mutation. For carriers of the high-risk variants (MLH1, MSH2 and EPCAM) who have already developed colon cancer, it is strongly recommended a subtotal or total colectomy is performed, while partial colectomy followed by endoscopic surveillance is an appropriate management approach to treat colon cancer in carriers of the low-risk variants (MSH6 and PMS2). On the other hand, extended surgery for index rectal cancer (such as total proctocolectomy) is less effective than extended surgery for index colon cancer from the point of view of metachronous CRC risk reduction, and is associated with a decreased quality of life.

Influence of Genetic Polymorphisms on the Age at Cancer Diagnosis in a Homogenous Lynch Syndrome Cohort of Individuals Carrying the MLH1:c.1528C>T South African Founder Variant

Background: High variability in the age at cancer diagnosis in Lynch syndrome (LS) patients is widely observed, even among relatives with the same germline pathogenic variant (PV) in the mismatch repair (MMR) genes. Genetic polymorphisms and lifestyle factors are thought to contribute to this variability. We investigated the influence of previously reported genetic polymorphisms on the age at cancer diagnosis in a homogenous LS cohort with a South African founder germline PV c.1528C>T in the MLH1 gene. Methods: A total of 359 LS variant heterozygotes (LSVH) from 60 different families were genotyped for specific genetic polymorphisms in GSTM1, GSTT1, CYP1A1, CYP17, PPP2R2B, KIF20A, TGFB1, XRCC5, TNF, BCL2, CHFR, CDC25C, ATM, TTC28, CDC25C, HFE, and hTERT genes using Multiplex Polymerase Chain Reaction and MassArray methods. Kaplan-Meier survival analysis, univariate and multivariate Cox proportional hazards gamma shared frailty models adjusted for sex were used to estimate the association between age at cancer diagnosis and polymorphism genotypes. A p-value < 0.05 after correcting for multiple testing using the Benjamini-Hochberg method was considered significant at a 95% confidence interval. Results: We identified three genotypes in the cell-cycle regulation, DNA repair, and xenobiotic-metabolism genes significantly associated with age at cancer diagnosis in this cohort. The CYP1A1 rs4646903 risk (GG) and CDC25C rs3734166 polymorphic (GA+AA) genotypes were significantly associated with an increased risk of a younger age at cancer diagnosis (Adj HR: 2.03 [1.01-4.08], p = 0.034 and Adj HR: 1.53 [1.09-2.14], p = 0.015, respectively). LSVH who were heterozygous for the XRCC5 rs1051685 SNP showed significant protection against younger age at cancer diagnosis (Adj HR: 0.69 [CI, 0.48-0.99], p = 0.043). The risk of a younger age at any cancer diagnosis was significantly high in LS carriers of one to two risk genotypes (Adj HR: 1.49 [CI: 1.06-2.09], corrected p = 0.030), while having one to two protective genotypes significantly reduced the risk of developing any cancer and CRC at a younger age (Adj HR: 0.52 [CI: 0.37-0.73], and Adj HR: 0.51 [CI: 0.36-0.74], both corrected p < 0.001). Conclusions: Polymorphism genotypes in the cell-cycle regulation, DNA repair, and xenobiotic metabolizing genes may influence the age at cancer diagnosis in a homogenous LS cohort with a South African founder germline PV c.1528C>T in the MLH1 gene.

High Probability of Lynch Syndrome Among Colorectal Cancer Patients Is Associated With Higher Occurrence of KRAS and PIK3CA Mutations

Background

In Indonesia, early-onset colorectal cancer (EOCRC) rates are higher in patients < 50 years old compared to Western populations, possibly due to a higher frequency of Lynch syndrome (LS) in CRC patients. We aimed to examine the association of KRAS and PIK3CA mutations with LS.

Methods

In this retrospective cross-sectional single-center study, the PCR-HRM-based test was used for screening of microsatellite instability (MSI) mononucleotide markers (BAT25, BAT26, BCAT25, MYB, EWSR1), MLH1 promoter methylation, and oncogene mutations of BRAF (V600E), KRAS (exon 2 and 3), and PIK3CA (exon 9 and 20) in FFPE DNA samples.

Results

All the samples (n = 244) were from Dr. Sardjito General Hospital Yogyakarta, Indonesia. KRAS and PIK3CA mutations were found in 151/244 (61.88%) and 107/244 (43.85%) of samples, respectively. KRAS and PIK3CA mutations were significantly associated with MSI status in 32/42 (76.19%) and 25/42 (59.52%) of samples, respectively. KRAS mutation was significantly associated with LS status in 26/32 (81.25%) of samples. The PIK3CA mutation was present in a higher proportion in LS samples of 19/32 (59.38%), but not statistically significant. Clinicopathology showed that KRAS mutation was significantly associated with right-sided CRC and higher histology grade in 39/151 (25.83%) and 24/151 (16.44%) samples, respectively. PIK3CA mutation was significantly associated with female sex and lower levels of tumor-infiltrating lymphocytes in 62/107 (57.94%) and 26/107 (30.23%) samples, respectively. KRAS and PIK3CA mutations did not significantly affect overall survival (120 months) in LS and non-LS patients.

Conclusions

The high probability of LS in Indonesian CRC patients is associated with KRAS and PIK3CA mutations.

Biallelic EPCAM deletions induce tissue-specific DNA repair deficiency and cancer predisposition

We report a case of Mismatch Repair Deficiency (MMRD) caused by germline homozygous EPCAM deletion leading to tissue-specific loss of MSH2. Through the use of patient-derived cells and organoid technologies, we performed stepwise in vitro differentiation of colonic and brain organoids from reprogrammed EPCAMdel iPSC derived from patient fibroblasts. Differentiation of iPSC to epithelial-colonic organoids exhibited continuous increased EPCAM expression and hypermethylation of the MSH2 promoter. This was associated with loss of MSH2 expression, increased mutational burden, MMRD signatures and MS-indel accumulation, the hallmarks of MMRD. In contrast, maturation into brain organoids and examination of blood and fibroblasts failed to show similar processes, preserving MMR proficiency. The combined use of iPSC, organoid technologies and functional genomics analyses highlights the potential of cutting-edge cellular and molecular analysis techniques to define processes controlling tumorigenesis and uncovers a new paradigm of tissue-specific MMRD, which affects the clinical management of these patients.

Identification of MKI67, TPR , and TCHH Mutations as Prognostic Biomarkers for Patients With Defective Mismatch Repair Colon Cancer Stage II/III

BACKGROUND

Stage II/III disease is the most predominant form of colorectal cancer, accounting for approximately 70% of cases. Furthermore, approximately 15% to 20% of patients with stage II/III disease have deficient mismatch repair or microsatellite instability-high colorectal cancer. However, there are no identified significant prognostic biomarkers for this disease.

OBJECTIVE

To identify prognostic markers for patients with deficient mismatch repair/microsatellite instability-high colon cancer stage II/III.

DESIGN

Retrospective study design.

SETTING

The study was conducted at a high-volume colorectal center, the Cancer Hospital, Chinese Academy of Medical Sciences.

PATIENTS

Patients diagnosed with stage II/III deficient mismatch repair/microsatellite instability-high colon cancer who underwent curative surgery at the Cancer Hospital at the Chinese Academy of Medical Sciences between July 2015 and November 2018 were included.

MAIN OUTCOME MEASURES

The primary outcome measure was the influence of differentially mutated genes on progression-free survival.

RESULTS

The retrospective deficient mismatch repair/microsatellite instability-high cohort involved 32 patients and The Cancer Genome Atlas-microsatellite instability-high cohort involved 45 patients. Patients with deficient mismatch repair/microsatellite instability-high colon cancer had higher mutational frequencies of MKI67 , TPR , and TCHH than patients with microsatellite stable colon cancer. MKI67 , TPR , TCHH , and gene combination were significantly correlated with prognosis. The biomarker mutation-type colon cancer group had a higher risk of recurrence or death than did the wild-type group. Moreover, biomarker mutation-type tumors had more mutations in the DNA damage repair pathway and tumor mutational burden than did biomarker wild-type tumors.

LIMITATIONS

This study was limited by its retrospective nature.

CONCLUSIONS

MKI67 , TPR , and TCHH may serve as potential diagnostic and prognostic biomarkers for deficient mismatch repair/microsatellite instability-high colon cancer stage II/III.

IDENTIFICACIN DE MUTACIONES MKI, TPR Y TCHH COMO BIOMARCADORES PRONSTICOS PARA PACIENTES CON CNCER DE COLON EN ETAPA II/III CON DEFICIENCIA EN LA REPARACION DE ERRORES DE EMPAREJAMIENTO

ANTECEDENTES:La enfermedad en estadio II/III es la forma más predominante de cáncer colorrectal y representa aproximadamente el 70% de los casos. Además, aproximadamente entre el 15% y el 20% de los pacientes con enfermedad en estadio II/III tienen reparación deficiente de errores de emparejamiento o inestabilidad de microsatélital alta. Sin embargo, no se han identificado biomarcadores pronósticos significativos para esta enfermedad.OBJETIVO:Este estudio tuvo como objetivo identificar marcadores pronósticos para pacientes con cáncer de colon con reparación deficiente de errores de emparejamiento/inestabilidad microsatelital alta en estadio II/III.DISEÑO:Diseño de estudio retrospectivo.ESCENARIO:El estudio se realizó en un centro colorrectal de alto volumen, el Hospital del Cáncer de la Academia China de Ciencias Médicas.PACIENTES:Pacientes diagnosticados con cáncer de colon en estadio II/III con reparación deficiente de errores de emparejamiento o inestabilidad de microsatélital alta que se sometieron a cirugía curativa en el Hospital del Cáncer de la Academia China de Ciencias Médicas entre julio de 2015 y noviembre de 2018.MEDIDAS DE RESULTADO PRINCIPALES:La medida de resultado primaria fue la influencia de los genes con mutaciones diferenciales en la supervivencia libre de progresión.RESULTADOS:La cohorte retrospectiva de reparación deficiente de errores de emparejamiento o inestabilidad de microsatélital alta y la cohorte de inestabilidad microsatelital alta del Atlas del Genoma del Cáncer involucraron a 32 y 45 pacientes, respectivamente. Los pacientes con de reparación deficiente de errores de emparejamiento/inestabilidad microsatélital alta tuvieron frecuencias mutacionales más altas de MKI67 , TPR y TCHH que los pacientes estables de microsatélites. MKI67 , TPR , TCHH , y la combinación de genes se correlacionaron significativamente con el pronóstico. El grupo de cáncer de colon de tipo mutación de biomarcador tenía un mayor riesgo de recurrencia o muerte que el grupo de mutación salvaje. Además, los tumores de tipo mutación de biomarcadores tenían más mutaciones en la vía de reparación del daño del ADN y la carga mutacional del tumor que los tumores de tipo salvaje de biomarcadores.LIMITACIONES:Este estudio estuvo limitado por su naturaleza retrospectiva.CONCLUSIONES:MKI67 , TPR , y TCHH pueden servir como posibles biomarcadores de diagnóstico y pronóstico para cáncer de colon en estadio II/III con reparación deficiente de errores de emparejamiento/inestabilidad microsatélital alta. (Traducción-Dr. Jorge Silva Velazco ).

Dietary behaviours of individuals with lynch syndrome at high risk of colorectal cancer: Results from the AAS-lynch study

BACKGROUND & AIMS

Individuals with Lynch syndrome (LS) have a high lifetime risk of developing colorectal cancer (CRC) due to genetic alterations. Nutrition is one of the main modifiable risk factors for sporadic CRC, however this has not been established in LS patients. The present study aimed to give a detailed overview of dietary intakes in individuals with LS, and associated individual characteristics.

METHODS

Dietary behaviours of individuals with LS from the AAS-Lynch clinical trial (2017-2022) were obtained using a food frequency questionnaire. Dietary intakes, food group consumption and overall diet quality (dietary patterns, adherence to the Mediterranean diet) were described according to sociodemographic, anthropometric and clinical characteristics, and compared to participants without LS from the NutriNet-Santé study (matched on sex, age, BMI and region).

RESULTS

280 individuals with LS were included in this analysis and matched with 547 controls. Compared to controls, LS patients consumed less fibre, legumes, fruit and vegetables and more red and processed meat (all p < 0.01). They also had a lower Mediterranean diet score (p = 0.002). Among LS patients, men, younger patients, or those with disadvantaged situation had a diet of poorer nutritional quality with lower adherence to a "Healthy" diet (all p ≤ 0.01). LS Patients with prevalent CRC had a higher consumption of dairy products than recommended, while those with prevalent adenoma consumed more vegetables, and less sugar and sweets (all p ≤ 0.01).

CONCLUSIONS

Although patients with LS were aware of their high lifetime risk of developing cancer, their diets were not optimal and included nutritional risk factors associated to CRC.

Lynch Syndrome Biopathology and Treatment: The Potential Role of microRNAs in Clinical Practice

Lynch syndrome (LS), also known as Hereditary Non-Polyposis Colorectal Cancer (HNPCC), is an autosomal dominant cancer syndrome which causes about 2-3% of cases of colorectal carcinoma. The development of LS is due to the genetic and epigenetic inactivation of genes involved in the DNA mismatch repair (MMR) system, causing an epiphenomenon known as microsatellite instability (MSI). Despite the fact that the genetics of the vast majority of MSI-positive (MSI+) cancers can be explained, the etiology of this specific subset is still poorly understood. As a possible new mechanism, it has been recently demonstrated that the overexpression of certain microRNAs (miRNAs, miRs), such as miR-155, miR-21, miR-137, can induce MSI or modulate the expression of the genes involved in LS pathogenesis. MiRNAs are small RNA molecules that regulate gene expression at the post-transcriptional level by playing a critical role in the modulation of key oncogenic pathways. Increasing evidence of the link between MSI and miRNAs in LS prompted a deeper investigation into the miRNome involved in these diseases. In this regard, in this study, we discuss the emerging role of miRNAs as crucial players in the onset and progression of LS as well as their potential use as disease biomarkers and therapeutic targets in the current view of precision medicine.

Prevalence and Clinical Implications of Mismatch Repair-Proficient Colorectal Cancer in Patients With Lynch Syndrome

PURPOSE

Lynch syndrome (LS)-associated colorectal cancer (CRC) is characterized by mismatch repair-deficiency (MMR-D) and/or microsatellite instability (MSI). However, with increasing utilization of germline testing, MMR-proficient (MMR-P) and/or microsatellite stable (MSS) CRC has also been observed. We sought to characterize MMR-P/MSS CRC among patients with LS.

METHODS

Patients with solid tumors with germline MMR pathogenic/likely pathogenic (P/LP) variants were identified on a prospective matched tumor-normal next-generation sequencing (NGS) protocol. CRCs were evaluated for MMR-D via immunohistochemical (IHC) staining and/or MSI via NGS. Clinical variables were correlated with MMR status using nonparametric tests.

RESULTS

Among 17,617 patients with solid tumors, 1.4% (n = 242) had LS. A total of 36% (86 of 242) of patients with LS had at least one CRC that underwent NGS profiling, amounting to 99 pooled CRCs assessed. A total of 10% (10 of 99) of CRCs were MMR-P, with 100% concordance between MSS status and retained MMR protein staining. A total of 89% (8 of 9) of patients in the MMR-P group had MSH6 or PMS2 variants, compared with 30% (23 of 77) in the MMR-D group (P = .001). A total of 46% (6 of 13) of PMS2+ patients had MMR-P CRC. The median age of onset was 58 and 43 years for MMR-P and MMR-D CRC, respectively (P = .07). Despite the later median age of onset, 40% (4 of 10) of MMR-P CRCs were diagnosed <50. A total of 60% (6 of 10) of MMR-P CRCs were metastatic compared with 13% (12 of 89) of MMR-D CRCs (P = .002). A total of 33% (3 of 9) of patients with MMR-P CRC did not meet LS testing criteria.

CONCLUSION

Patients with LS remained at risk for MMR-P CRC, which was more prevalent among patients with MSH6 and PMS2 variants. MMR-P CRC was later onset and more commonly metastatic compared with MMR-D CRC. Confirmation of tumor MMR/MSI status is critical for patient management and familial risk estimation.

Microsatellite Instability: A Review of Molecular Epidemiology and Implications for Immune Checkpoint Inhibitor Therapy

Microsatellite instability (MSI) is one of the most important molecular characteristics of a tumor, which occurs among various tumor types. In this review article, we examine the molecular characteristics of MSI tumors, both sporadic and Lynch-associated. We also overview the risks of developing hereditary forms of cancer and potential mechanisms of tumor development in patients with Lynch syndrome. Additionally, we summarize the results of major clinical studies on the efficacy of immune checkpoint inhibitors for MSI tumors and discuss the predictive role of MSI in the context of chemotherapy and checkpoint inhibitors. Finally, we briefly discuss some of the underlying mechanisms causing therapy resistance in patients treated with immune checkpoint inhibitors.

The Polish Society of Gynecological Oncology Guidelines for the Diagnosis and Treatment of Endometrial Carcinoma (2023)

BACKGROUND

Due to the increasing amount of published data suggesting that endometrial carcinoma is a heterogenic entity with possible different treatment sequences and post-treatment follow-up, the Polish Society of Gynecological Oncology (PSGO) has developed new guidelines.

AIM

to summarize the current evidence for diagnosis, treatment, and follow-up of endometrial carcinoma and to provide evidence-based recommendations for clinical practice.

METHODS

The guidelines have been developed according to standards set by the guideline evaluation tool AGREE II (Appraisal of Guidelines for Research and Evaluation). The strength of scientific evidence has been defined in agreement with The Agency for Health Technology Assessment and Tariff System (AOTMiT) guidelines for scientific evidence classification. The grades of recommendation have been based on the strength of evidence and the level of consensus of the PSGO development group.

CONCLUSION

Based on current evidence, both the implementation of the molecular classification of endometrial cancer patients at the beginning of the treatment sequence and the extension of the final postoperative pathological report of additional biomarkers are needed to optimize and improve treatment results as well as to pave the route for future clinical trials on targeted therapies.

MyLynch: A Patient-Facing Clinical Decision Support Tool for Genetically-Guided Personalized Medicine in Lynch Syndrome

Lynch syndrome (LS) is a hereditary cancer susceptibility condition associated with varying cancer risks depending on which of the five causative genes harbors a pathogenic variant; however, lifestyle and medical interventions provide options to lower those risks. We developed MyLynch, a patient-facing clinical decision support (CDS) web application that applies genetically-guided personalized medicine (GPM) for individuals with LS. The tool was developed in R Shiny through a patient-focused iterative design process. The knowledge base used to estimate patient-specific risk leveraged a rigorously curated literature review. MyLynch informs LS patients of their personal cancer risks, educates patients on relevant interventions, and provides patients with adjusted risk estimates, depending on the interventions they choose to pursue. MyLynch can improve risk communication between patients and providers while also encouraging communication among relatives with the goal of increasing cascade testing. As genetic panel testing becomes more widely available, GPM will play an increasingly important role in patient care, and CDS tools offer patients and providers tailored information to inform decision-making. MyLynch provides personalized cancer risk estimates and interventions to lower these risks for patients with LS.

Challenges of chimeric antigen receptor-T/natural killer cell therapy in the treatment of solid tumors: focus on colorectal cancer and evaluation of combination therapies

Colorectal cancer (CRC) is the second most common cancer globally and one of the deadliest human malignancies. Traditional therapies, such as surgery, chemotherapy, and combination therapies have been used to treat patients with CRC. However, recently immunotherapy has been considered a practical and attractive therapeutic approach in various cancers, such as CRC. Among the immunotherapy methods, chimeric antigen receptor (CAR)-T, and CAR-natural killer cells (NK) cells therapy have been significantly successful, mainly in treating hematological malignancies. However, the effectiveness of CAR-T/NK cell therapy in the treatment of solid tumors, such as CRC has been less than blood malignancies due to various challenges, such as the selection of tumor antigens, lack of proper trafficking in tumor tissue, immunosuppressive tumor microenvironment, tumor heterogeneity and, adverse effects during and after CAR-T/NK cell therapy. This review summarized the biological structure of CAR-T/NK cells and their use in various types of human malignancies, particularly CRC, as well as the challenges of this type of treatment and the outcome of related combination therapies.

Identification of Lynch Syndrome in Patients with Endometrial Cancer Based on a Germline Next Generation Sequencing Multigene Panel Test

We aimed to investigate the prevalence and relative contributions of LS and non-LS mutations in patients with endometrial cancer in Korea. We retrospectively reviewed the medical records of 204 patients diagnosed with endometrial cancer who underwent a germline next generation sequencing multigene panel test covering MLH1, MSH2, MSH6, PMS2, and EPCAM at three tertiary centers. Thirty patients (14.7%) with pathogenic mutations (12 MLH1; 6 MSH2; 10 MSH6; 2 PMS2) and 20 patients (9.8%) with 22 unclassified variants (8 MLH1; 8 MSH2; 2 MSH6; 3 PMS2; 1 EPCAM) were identified. After excluding four close relatives of a proband, the prevalence of LS was 13.0% (26/200). Patients with LS were more likely than those with sporadic cancer to be younger at diagnosis (48 vs. 53 years, p = 0.045) and meet the Amsterdam II criteria (66.7 vs. 3.5%, p < 0.001). Non-endometrioid histology was more prevalent in patients with MSH6 or PMS2 mutations (41.7%) than those with MLH1 or MSH2 mutations (5.6%, p = 0.026). In this pre-selected cohort of endometrial cancer patients who underwent next generation sequencing, the prevalence of LS was 13%, thus supporting the use of gene panel testing for endometrial cancer patients.

Identifying patients with Lynch syndrome using a universal tumor screening program in an integrated healthcare system

INTRODUCTION

Lynch syndrome (LS) is associated with an increased risk of colorectal (CRC) and endometrial (EC) cancers. Universal tumor screening (UTS) of all individuals diagnosed with CRC and EC is recommended to increase identification of LS. Kaiser Permanente Northwest (KPNW) implemented a UTS program for LS among individuals newly diagnosed with CRC in January 2016 and EC in November 2016. UTS at KPNW begins with immunohistochemistry (IHC) of tumor tissue to determine loss of mismatch repair proteins associated with LS (MLH1, MSH2, MSH6, and PMS2)., IHC showing loss of MLH1 is followed by reflex testing (automatic testing) to detect the presence of the BRAF V600E variant (in cases of CRC) and MLH1 promoter hypermethylation to rule out likely sporadic cases.

MATERIALS AND METHODS

Individuals newly diagnosed with CRC and EC were identified between the initiation of the respective UTS programs and July 2018. Electronic medical records were reviewed to extract patient data related to UTS, including IHC and reflex testing results, date of referrals to the genetics department, and results of germline genetic testing for LS.

RESULTS

313 out of 362 individuals diagnosed with CRC and 61 out of 64 individuals diagnosed with EC who were eligible were screened by IHC for LS. Most (47/52 or 90%, including 46/49 CRC and 1/3 EC) individuals that were not screened by IHC only had a biopsy sample available. Fourteen individuals (3.7% overall, including 13/313 CRC and 1/61 EC) received an abnormal result after reflex testing and were referred for genetic counseling. Of these, 10 individuals (71% overall, including 9/13 CRC and 1/1 EC) underwent germline genetic testing for LS. Five individuals diagnosed with CRC were found to have pathogenic variants. in PMS2 (n = 3), MLH1 (n = 1), and MSH6 (n = 1). No pathogenic variants were identified in individuals diagnosed with EC.

CONCLUSIONS

UTS identified individuals at risk for LS. Most individuals who screened positive for LS had follow-up germline genetic testing for LS. The consistent use of biopsy samples is an opportunity to improve UTS.

Lynch syndrome caused by a novel deletion of the promoter and exons 1-13 of MLH1 gene

Lynch syndrome (LS) is the most common hereditary cancer syndrome involving multiple organ systems. The mutation patterns of the involved major DNA mismatch repair (MMR) genes, namely MLH1, MSH2, MSH6, and PMS2, have not been fully elucidated. Herein, we report a case of LS caused by a novel large deletion in the promoter and exons 1-13 of MLH1 gene. A 30 year-old male was admitted for dull abdominal pain for 5 months with family history significant for dominant familial colon cancer. Abdominal computed tomography (CT) revealed masses in colon, lung and liver. His-plasma CA19-9 was 1250 units/ml and CEA 133 ng/ml. Targeted liver biopsy showed metastatic adenocarcinoma. Immunocytochemically, the tumor cells were positive for CK20 and CDX2, and displayed loss of MLH1 and PMS2 expression but with intact MSH2 and MSH6 proteins. Next-generation sequencing of the liver metastasis demonstrated copy loss of MLH1 gene spanning exons 1 to 13. Further SNP array detected copy neutral loss of heterozygosity (CN-LOH) expanding the short arm of chromosome 3p21.3 to 3pter regions and a 219 kb deletion involving the promoter and first 13 exons of MLH1 gene (arr[GRCh37] 3p22.2(36,856,328_37075457)x1). Germline sequencing using a blood sample confirmed the deletion of the MLH gene including the promoter and this first 13 exons (NG_007109.2(NM_000249.3:c.(?_-198)_(1558+1_1559-1)del). In summary, we identified a novel MLH1 mutation pattern of partial deletion and CN-LOH causing LS.

Cancer Predisposition Genes in Adolescents and Young Adults (AYAs): a Review Paper from the Italian AYA Working Group

PURPOSE OF REVIEW

The present narrative systematic review summarizes current knowledge on germline gene mutations predisposing to solid tumors in adolescents and young adults (AYAs).

RECENT FINDINGS

AYAs with cancer represent a particular group of patients with specific challenging characteristics and yet unmet needs. A significant percentage of AYA patients carry pathogenic or likely pathogenic variants (PV/LPVs) in cancer predisposition genes. Nevertheless, knowledge on spectrum, frequency, and clinical implications of germline variants in AYAs with solid tumors is limited. The identification of PV/LPV in AYA is especially critical given the need for appropriate communicative strategies, risk of second primary cancers, need for personalized long-term surveillance, potential reproductive implications, and cascade testing of at-risk family members. Moreover, these gene alterations may potentially provide novel biomarkers and therapeutic targets that are lacking in AYA patients. Among young adults with early-onset phenotypes of malignancies typically presenting at later ages, the increased prevalence of germline PV/LPVs supports a role for genetic counseling and testing irrespective of tumor type.

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

Background

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

Case Presentation

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

Conclusion

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

Risk-Reducing Bilateral Salpingo-Oophorectomy for Ovarian Cancer: A Review and Clinical Guide for Hereditary Predisposition Genes

Pathogenic germline variants underlie up to 20% of ovarian cancer (OC) and are associated with varying degrees of risk for OC. For mutations in high-penetrance genes such as BRCA1/2, the role of risk-reducing bilateral salpingo-oophorectomy (RRSO) in cancer prevention is well-established and improves mortality. However, in moderate-penetrance genes where the degree of risk for OC is less precisely defined, the role of RRSO is more controversial. Although national guidelines have evolved to incorporate gene-specific recommendations, studies demonstrate significant variations in practice. Given this, our multidisciplinary group has reviewed the available literature on risk estimates for genes associated with OC, incorporated levels of evidence, and set thresholds for consideration of RRSO. We found that the benefit of RRSO is well-established for pathogenic variants in BRCA1/2 as well as BRIP1 and RAD51C/D where the risk of OC is elevated beyond our threshold for RRSO. In PALB2, RRSO is particularly controversial as newer studies consistently demonstrate an increased risk of OC that is dependent on family history, making uniform recommendations challenging. Additionally, new guidelines for Lynch syndrome provide gene-specific risks, questioning the role of RRSO, and even hysterectomy, for MSH6 and PMS2 mutation carriers. Given these uncertainties, shared decision making should be used around RRSO with discussion of individual risk factors, family history, and adverse effects of surgery and premature menopause. Herein, we provide a clinical guide and counseling points.

Chinese consensus on prevention of colorectal neoplasia (2021, Shanghai)

Most patients with colorectal cancer (CRC) were diagnosed in advanced stage and the prognosis is poor. Therefore, early detection and prevention of CRC are very important. As with other cancers, there is also the tertiary prevention for CRC. The primary prevention is etiological prevention, which is mainly the treatment of adenoma or inflammation for preventing the development into cancer. The secondary prevention is the early diagnosis and early treatment for avoiding progressing to advanced cancer. The tertiary prevention belongs to the broad category of prevention, mainly for advanced CRC, through surgical treatment and postoperative adjuvant chemotherapy, radiotherapy, targeted therapy, immunotherapy for preventing tumor recurrence or metastasis. This consensus is based on the recent domestic and international consensus guidelines and the latest progress of international researches in the past five years. This consensus opinion seminar was hosted by the Chinese Society of Gastroenterology and Cancer Collaboration Group of Chinese Society of Gastroenterology, and was organized by the Division of Gastroenterology and Hepatology & Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University. The consensus opinion contains 60 statement clauses, the standard and basis of the evidence-based medicine grade and voting grade of the statement strictly complied with the relevant international regulations and practice.

Molecular Features and Clinical Management of Hereditary Pancreatic Cancer Syndromes and Familial Pancreatic Cancer

Hereditary pancreatic cancers are caused by several inherited genes. Familial pancreatic cancer is defined as pancreatic cancer arising in a patient with at least two first-degree relatives with pancreatic cancer in the absence of an identified genetic cause. Hereditary pancreatic cancer syndromes and familial pancreatic cancers account for about 10% of pancreatic cancer cases. Germline mutations in BRCA1, BRCA2, ATM, PALB2, CDKN2A, STK11, and TP53 and mismatch repair genes (MLH1, MSH2, MSH6, PMS2, and EPCAM) are among the well-known inherited susceptibility genes. Currently available targeted medications include poly (ADP-ribose) polymerase inhibitors (PARP) for cases with mutant BRCA and immune checkpoint inhibitors for cases with mismatch repair deficiency. Loss of heterozygosity of hereditary pancreatic cancer susceptibility genes such as BRCA1/2 plays a key role in carcinogenesis and sensitivity to PARP inhibitors. Signature 3 identified by whole genome sequencing is also associated with homologous recombination deficiency and sensitivity to targeted therapies. In this review, we summarize molecular features and treatments of hereditary pancreatic cancer syndromes and surveillance procedures for unaffected high-risk cases. We also review transgenic murine models to gain a better understanding of carcinogenesis in hereditary pancreatic cancer.

Genotypic and Phenotypic Characteristics of Hereditary Colorectal Cancer

The genomic causes and clinical manifestations of hereditary colorectal cancer (HCRC) might be stratified into 2 groups, namely, familial (FCRC) and a limited sense of HCRC, respectively. Otherwise, FCRC is canonically classified into 2 major categories; Lynch syndrome (LS) or associated spectra and inherited polyposis syndrome. By contrast, despite an increasing body of genotypic and phenotypic traits, some FCRC cannot be clearly differentiated as definitively single type, and the situation has become more complex as additional causative genes have been discovered. This review provides an overview of HCRC, including 6 LS or associated spectra and 8 inherited polyposis syndromes, according to molecular pathogenesis. Variants and newly-identified FCRC are particularly emphasized, including MUTYH (or MYH)-associated polyposis, Muir-Torre syndrome, constitutional mismatch repair deficiency, EPCAM-associated LS, polymerase proofreading-associated polyposis, RNF43- or NTHL1-associated serrated polyposis syndrome, PTEN hamartoma tumor syndrome, and hereditary mixed polyposis syndrome. We also comment on the clinical utility of multigene panel tests, focusing on comprehensive cancer panels that include HCRC. Finally, HCRC surveillance strategies are recommended, based on revised or notable concepts underpinned by competent validation and clinical implications, and favoring major guidelines. As hereditary syndromes are mainly attributable to genomic constitutions of distinctive ancestral groups, an integrative national HCRC registry and guideline is an urgent priority.

Mismatch repair and clinical response to immune checkpoint inhibitors in endometrial cancer

Endometrial cancer is common, and a subset recurs and requires additional treatment.

Some of these are recognized as being susceptible to immune therapies and are said to have mismatch repair deficiency (dMMR).

However, this clinical trial highlights which cases are more likely to respond well: those containing mutations in genes known as Lynch genes and also some with mutations in POLE/POLD1 (“ultra‐hypermutation” genes).

In contrast, the majority of dMMR endometrial cancers have silencing or DNA methylation of one of these genes, MLH1, and do not seem to be as responsive to single‐agent immune therapy.

The availability of combination therapies may be important to consider for these women.

This hypothesis‐driving study highlights the need for further evaluation of the interaction between immune checkpoint inhibitor therapy responses and the mechanism of DNA mismatch repair (MMR) deficiency. Although MMR gene germline pathogenic variant carriers and Lynch‐like tumors with double somatic MMR gene mutations are highly likely to respond to a single‐agent immune checkpoint inhibitor (ICI), those with MLH1 hypermethylation may benefit from additional agents to induce an ICI response.

Whole-Genome Profiles of Malay Colorectal Cancer Patients with Intact MMR Proteins

BACKGROUND

This study aimed to identify new genes associated with CRC in patients with normal mismatch repair (MMR) protein expression.

METHOD

Whole-genome sequencing (WGS) was performed in seven early-age-onset Malay CRC patients. Potential germline genetic variants, including single-nucleotide variations and insertions and deletions (indels), were prioritized using functional and predictive algorithms.

RESULTS

An average of 3.2 million single-nucleotide variations (SNVs) and over 800 indels were identified. Three potential candidate variants in three genes-IFNE, PTCH2 and SEMA3D-which were predicted to affect protein function, were identified in three Malay CRC patients. In addition, 19 candidate genes-ANKDD1B, CENPM, CLDN5, MAGEB16, MAP3K14, MOB3C, MS4A12, MUC19, OR2L8, OR51Q1, OR51AR1, PDE4DIP, PKD1L3, PRIM2, PRM3, SEC22B, TPTE, USP29 and ZNF117-harbouring nonsense variants were prioritised. These genes are suggested to play a role in cancer predisposition and to be associated with cancer risk. Pathway enrichment analysis indicated significant enrichment in the olfactory signalling pathway.

CONCLUSION

This study provides a new spectrum of insights into the potential genes, variants and pathways associated with CRC in Malay patients.

Balanced Functional Module Detection in genomic data

Motivation

High-dimensional genomic data can be analyzed to understand the effects of variables on a target variable such as a clinical outcome. For understanding the underlying biological mechanism affecting the target, it is important to discover the complete set of relevant variables. Thus variable selection is a primary goal, which differs from a prediction criterion. Of special interest are functional modules, cooperating sets of variables affecting the target which can be characterized by a graph. In applications such as social networks, the concept of balance in undirected signed graphs characterizes the consistency of associations within the network. This property requires that the module variables have a joint effect on the target outcome with no internal conflict, an efficiency that may be applied to biological networks.

Results

In this paper, we model genomic variables in signed undirected graphs for applications where the set of predictor variables influences an outcome. Consequences of the balance property are exploited to implement a new module discovery algorithm, balanced Functional Module Detection (bFMD), which selects a subset of variables from high-dimensional data that compose a balanced functional module. Our bFMD algorithm performed favorably in simulations as compared to other module detection methods. Additionally, bFMD detected interpretable results in an application using RNA-seq data obtained from subjects with Uterine Corpus Endometrial Carcinoma using the percentage of tumor invasion as the outcome of interest. The variables selected by bFMD have improved interpretability due to the logical consistency afforded by the balance property.

Supplementary information

Supplementary data are available at Bioinformatics Advances online.

Increased risk of second primary malignancies among endometrial cancer survivors receiving surgery alone: A population-based analysis

Background

Women with endometrial cancer (EC) have favorable prognoses, leaving them vulnerable to the development of second primary cancers (SPCs). We investigated the SPC risk and survival outcomes among EC patients treated with surgery alone in order to exclude the impact of adjuvant treatment on the results.

Methods

Data from the Taiwan Cancer Registry from 1995 to 2013 were analyzed. Standardized incidence ratios (SIRs) of SPCs among EC survivors were calculated.

Results

Among 7725 women enrolled, 478 developed an SPC. The overall SIR for SPCs in EC survivors was 2.84 (95% confidence interval [CI] 2.59–3.10) compared with the general female population. Women diagnosed with EC at age <50 years had a higher SIR for an SPC than those diagnosed at age ≥50 years (SIR = 4.38 vs. 1.28). The most frequent site of an SPC was the small intestine (SIR = 8.39, 95% CI 2.72–19.58), followed by the kidney (SIR = 4.84, 95% CI 1.78–10.54), and oral cavity (SIR = 4.52, 95% CI 2.17–8.31). Women, regardless of age at EC diagnosis, had significantly higher SIRs for subsequent breast, colorectal, lung, and thyroid cancer, and lymphoma. Women with an SPC had shorter overall survival than those without (5‐year: 88.9 vs. 94.2%, 10‐year: 71.3 vs. 89.8%, 15‐year: 62.3 vs. 86.1%, and 20‐year: 47.6 vs. 81.1%, all ps<0.001).

Conclusions

Even women treated for EC with surgery alone, especially young EC survivors, had an increased risk of SPCs. Genetic counseling/testing is recommended for young EC patients, and all are recommended to receive regular surveillance and screening for breast, colorectal, and lung cancers.

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.

Educational Case: Hereditary Colorectal Cancer and Association With Endometrial Carcinoma

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040. ¹.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2020 for the Clinical Practice of Hereditary Colorectal Cancer

Hereditary colorectal cancer (HCRC) accounts for < 5% of all colorectal cancer cases. Some of the unique characteristics commonly encountered in HCRC cases include early age of onset, synchronous/metachronous cancer occurrence, and multiple cancers in other organs. These characteristics necessitate different management approaches, including diagnosis, treatment or surveillance, from sporadic colorectal cancer management. There are two representative HCRC, named familial adenomatous polyposis and Lynch syndrome. Other than these two HCRC syndromes, related disorders have also been reported. Several guidelines for hereditary disorders have already been published worldwide. In Japan, the first guideline for HCRC was prepared by the Japanese Society for Cancer of the Colon and Rectum (JSCCR), published in 2012 and revised in 2016. This revised version of the guideline was immediately translated into English and published in 2017. Since then, several new findings and novel disease concepts related to HCRC have been discovered. The currently diagnosed HCRC rate in daily clinical practice is relatively low; however, this is predicted to increase in the era of cancer genomic medicine, with the advancement of cancer multi-gene panel testing or whole genome testing, among others. Under these circumstances, the JSCCR guidelines 2020 for HCRC were prepared by consensus among members of the JSCCR HCRC Guideline Committee, based on a careful review of the evidence retrieved from literature searches, and considering the medical health insurance system and actual clinical practice settings in Japan. Herein, we present the English version of the JSCCR guidelines 2020 for HCRC.

Recent advances in Lynch syndrome

Lynch syndrome is one of the most common hereditary cancer syndromes and is characterized by the development of many cancers, such as colorectal cancer (CRC), endometrial cancer, ovarian cancer, stomach cancer and many other cancers. Lynch syndrome is caused by pathogenic germline variants in one of four DNA mismatch repair genes (MLH1, MSH2, MSH6, or PMS2) or by an EPCAM deletion. The MLH1 variant is correlated with the highest risk of CRC, while the MSH2 variant is correlated with the highest risk of other cancers. CRC is the most common cancer type that develops in individuals with Lynch syndrome, followed by endometrial cancer. Recent advances have been made to help us further understand the molecular pathogenesis of this disease and help improve diagnostic testing efficiency and surveillance strategies. Moreover, recent advances in immunotherapy provided by clinical trials also provide clinicians with more chances to better treat Lynch syndrome. This study aims to review many advances in the molecular genetics, clinical features, diagnosis, surveillance and treatment of Lynch syndrome.

Clinical activity of durvalumab for patients with advanced mismatch repair-deficient and repair-proficient endometrial cancer. A nonrandomized phase 2 clinical trial

BACKGROUND

In this study, we assessed the activity of durvalumab, an antibody to programmed death ligand-1, in two cohorts of women with advanced endometrial cancers (AEC)-mismatch repair proficient (pMMR) and mismatch repair deficient (dMMR).

METHODS

A multicenter phase two study was performed in women with AEC with pMMR tumor progressing after one to three lines of chemotherapy and women with AEC with dMMR tumor progressing after zero to three lines of chemotherapy. Mismatch repair status was based on immunohistochemistry expression. All women received durvalumab 1500 mg given every 4 weeks until progression or unacceptable toxicity. The primary endpoint was objective tumor response by RECIST V.1.1 modified for immune-based therapeutics.

RESULTS

Seventy-one women were recruited: 35 dMMR and 36 pMMR. Median follow-up was 19 vs 21 months in dMMR versus pMMR, respectively. Median age was 67 years. Histology in dMMR versus pMMR included endometrioid (94% vs 57%) and serous (0% vs 31%) and was high grade in 26% vs 74%. The objective tumor response rate (OTRR) in the dMMR cohort was 47% (17/36, 95% CI 32 to 63), including 6 complete responses and 11 partial responses (PRs)) vs 3% in the pMMR cohort (1/35, 95% CI 1 to 15, PR). In the dMMR cohort, durvalumab was the first-line therapy in 58% (OTRR 57%) and the second-line therapy in 39% (OTRR 38%). Median progression-free survival was 8.3 months in the dMMR cohort vs 1.8 months in the pMMR cohort. The 12-month overall survival (OS) rate was 71% in dMMR vs 51% in pMMR, with median OS not reached for dMMR vs 12 months for pMMR. Immune-related adverse events occurred in 14 women, mostly grades 1-2.

CONCLUSION

Durvalumab monotherapy showed promising activity and acceptable safety in AEC with dMMR regardless of prior lines of chemotherapy, but activity was limited in AEC with pMMR.

TRIAL REGISTRATION NUMBERS

ANZGOG1601, ACTRN12617000106336, and NCT03015129.

Precision medicine for hereditary tumors in gynecologic malignancies

Genomic medicine for gynecologic tumors is characterized by hereditary breast and ovarian cancer (HBOC) and Lynch syndrome (LS). Poly ADP-ribose polymerase (PARP) inhibitor, olaparib, and the immune checkpoint inhibitor, pembrolizumab, which are drugs that show sensitivity to each hereditary tumor, have begun to spread in clinical practice for gynecologic malignancies. In clinical use, platinum sensitivity is used as a clinical surrogate marker for olaparib sensitivity, and microsatellite instability is used as a biological surrogate marker for pembrolizumab sensitivity. BRCA genetic testing and microsatellite instability test have been used as companion diagnostics before starting olaparib and pembrolizumab treatment, respectively. Homologous recombination deficiency test could be used for companion diagnostic of olaparib combination with bevacizumab in first-line maintenance treatment and niraparib without re-administration of platinum agents in the treatment of recurrence. The approval of the three drugs has been changing the treatment of gynecologic malignancies. Furthermore, preventive medical care has been covered by insurance since April 2020 for breast and/or ovarian cancer patients with germline BRCA1/2 mutation in Japan. This review article outlines the current status and future prospects of precision medicine for gynecologic hereditary tumors focusing on HBOC and LS.

Germline deletion of chromosome 2p16-21 associated with Lynch syndrome

We identified a Japanese patient with Lynch syndrome with a novel large germline deletion of chromosome 2p16-21, including the EPCAM, MSH2, and KCNK12 genes. The proband was a 46-year-old man with ascending colon cancer. The clinical significance of germline KCNK12 gene deletion, which encodes one of the subfamilies of two-pore-domain potassium channels, is still unknown.

Factors Impacting the Decision of an Individual With Lynch Syndrome to Terminate a Health Care Provider Relationship

Lynch syndrome (LS) is a genetic cancer syndrome that puts affected individuals at a significantly higher risk of developing multiple cancers. Participants (n = 57) were recruited through social media. Data were collected through online surveys and phone interviews; the interview data (n = 55) were analyzed to identify provider terminations and the factors that motivated these decisions. Results indicate that individuals with LS terminated their patient-provider relationships due to lack of provider LS knowledge, poor interactions, or a combination of both factors. Findings from this study suggest a need for better interactions between LS patients and providers and increased knowledge of LS-specific care.

Is a colorectal neoplasm diagnosis a trigger to change dietary and other lifestyle habits for persons with Lynch syndrome? A prospective cohort study

A cancer diagnosis is suggested to be associated with changes in dietary and lifestyle habits. Whether this applies to persons with familial cancer, such as Lynch syndrome (LS) is unknown. We investigated whether a colorectal neoplasm (CRN) diagnosis in persons with LS is associated with changes in dietary and lifestyle habits over time. We used data of confirmed LS mutation carriers from the GEOLynch study, a prospective cohort study. Information on dietary intake and lifestyle habits was collected with a validated semi-quantitative food frequency questionnaire and a general questionnaire administered at baseline (2006-2008) and follow-up (2012-2017). Participants' medical records were used to identify CRN diagnoses. Changes in dietary and lifestyle habits in the CRN and the no-CRN group were compared using multivariable linear regression models for continuous variables and cross-tables with percentage change at follow-up compared with baseline for categorical variables. Of the 324 included participants, 146 developed a CRN (CRN group) between baseline and follow-up, while 178 did not (no-CRN group). Smoking cessation was more often reported in the CRN than in the no-CRN group (41.4% vs. 35.0%). There were no differences in changes of energy intake, alcohol, red meat, processed meat, dairy, fruit, vegetables and dietary fiber consumption, BMI, physical activity and NSAID use. Apart from a potentially higher likelihood of smoking cessation, we found little evidence that a CRN diagnosis is associated with changes in lifestyle habits in persons with LS.

Prevalence of CNV-neutral structural genomic rearrangements in MLH1, MSH2, and PMS2 not detectable in routine NGS diagnostics

Routine diagnostics for colorectal cancer patients suspected of having Lynch-Syndrome (LS) currently uses Next-Generation-Sequencing (NGS) of targeted regions within the DNA mismatch repair (MMR) genes. This analysis can reliably detect nucleotide alterations and copy-number variations (CNVs); however, CNV-neutral rearrangements comprising gene inversions or large intronic insertions remain undetected because their breakpoints are usually not covered. As several founder mutations exist for LS, we established PCR-based screening methods for five known rearrangements in MLH1, MSH2, or PMS2, and investigated their prevalence in 98 German patients with suspicion of LS without a causative germline variant or CNV detectable in the four MMR genes. We found no recurrence of CNV-neutral structural rearrangements previously described: Neither for two inversions in MLH1 (exon 1 and exon 16-19) within 33 MLH1-deficient patients, nor for two inversions in MSH2 (exon 1-7 and exon 2-6) within 48 MSH2-deficient patients. The PMS2 insertion in intron 7 was detected in one of 17 PMS2-deficient patients. None of the four genomic inversions constitutes a founder event within the German population, but we advise to test the rare cases with unsolved PMS2-deficiency upon the known insertion. As a next diagnostic step, tumour tissue of the unsolved patients should be sequenced for somatic variants, and germline analysis of additional genes with an overlapping clinical phenotype should be considered. Alternatively, full-length cDNA analyses may detect concealed MMR-defects in cases with family history.

Diagnostic criteria for constitutional mismatch repair deficiency (CMMRD): recommendations from the international consensus working group

BACKGROUND

Constitutional mismatch repair deficiency syndrome (CMMRD) is the most aggressive cancer predisposition syndrome associated with multiorgan cancers, often presenting in childhood. There is variability in age and presentation of cancers and benign manifestations mimicking neurofibromatosis type 1. Genetic testing may not be informative and is complicated by pseudogenes associated with the most commonly associated gene, PMS2. To date, no diagnostic criteria exist. Since surveillance and immune-based therapies are available, establishing a CMMRD diagnosis is key to improve survival.

METHODS

In order to establish a robust diagnostic path, a multidisciplinary international working group, with representation from the two largest consortia (International Replication Repair Deficiency (IRRD) consortium and European Consortium Care for CMMRD (C4CMMRD)), was formed to establish diagnostic criteria based on expertise, literature review and consensus.

RESULTS

The working group established seven diagnostic criteria for the diagnosis of CMMRD, including four definitive criteria (strong evidence) and three likely diagnostic criteria (moderate evidence). All criteria warrant CMMRD surveillance. The criteria incorporate germline mismatch repair results, ancillary tests and clinical manifestation to determine a diagnosis. Hallmark cancers for CMMRD were defined by the working group after extensive literature review and consultation with the IRRD and C4CMMRD consortia.

CONCLUSIONS

This position paper summarises the evidence and rationale to provide specific guidelines for CMMRD diagnosis, which necessitates appropriate surveillance and treatment.

Historical review of Lynch syndrome

Lynch syndrome was formerly known as Hereditary Nonpolyposis Colorectal Cancer. Currently, these two nomenclatures each have their unique definitions and are no longer used interchangeably. The history of hereditary nonpolyposis colorectal cancer was first recognized formally in the literature by Henry Lynch in 1967. With advances of molecular genetics, there has been a transformation from clinical phenotype to genotype diagnostics. This has led to the ability to diagnose affected patients before they manifest with cancer, and therefore allow preventative surveillance strategies. Genotype diagnostics has shown a difference in penetrance of different cancer risks dependent on the gene containing the mutation. Surgery is recommended as prevention for some cancers; for others they are reserved for once cancer is noted. Various surveillance strategies are recommended dependent on the relative risk of cancer and the ability to intervene with surgery to impact on survival. Risk reduction through aspirin has shown some recent promise, and continues to be studied.

Clinicopathological and molecular characterization of Brazilian families at risk for Lynch syndrome

Lynch syndrome (LS), is the most common hereditary colorectal cancer syndrome. However, it is poorly characterized in Brazil. Therefore, we aimed to determine the spectrum of pathogenic variants in Mismatch Repair (MMR) genes and investigate the MLH1 promotor methylation role as a second hit in LS tumors. Tumor screening through microsatellite instability and immunohistochemistry for MMR proteins was performed in 323 cases who met clinical criteria. BRAF-V600E and MLH1 promoter methylation were analyzed for all MLH1-deficient tumors. Patients with MMR deficient tumor proceeded to germline genetic testing. MMR deficient tumors were detected in 41% of patients recruited. About half of patients carried a pathogenic germline variant. Two recurrent variants in MLH1 and three novel pathogenic variants were identified. Furthermore, pathogenic germline variants with concomitant somatic MLH1 hypermethylation were found in 6% of cases. Predictive genetic testing was offered to 387 relatives. Overall, 127 tumors were diagnosed in 100 LS patients, from 62 unrelated families. Our molecular data provide new information about the spectrum of MMR mutations, which contributes to a better characterization of LS in Brazil. Furthermore, we call attention to the possibility of failure in the diagnosis of germline MLH1 mutation carriers when somatic MLH1 hypermethylation is used to rule out LS.

Associations of Height With the Risks of Colorectal and Endometrial Cancer in Persons With Lynch Syndrome

People with Lynch syndrome (LS), who carry a pathogenic mutation in a DNA mismatch repair gene, have increased risks of colorectal cancer (CRC) and endometrial cancer (EC). A high reported variability in cancer risk suggests the existence of factors that modify cancer risk for persons with LS. We aimed to investigate the associations between height and CRC and EC risk for persons with LS using data from 2 large studies. Information on 1,115 men and 1,553 women with LS from the Colon Cancer Family Registry (1998–2007) and the GEOLynch Cohort Study (2006–2017) was harmonized. We used weighted Cox proportional hazards regression models with age on the time axis to estimate adjusted hazard ratios and 95% confidence intervals for each 5-cm increment in self-reported height. CRC was diagnosed in 947 persons during 65,369 person-years of observation, and 171 women were diagnosed with EC during 39,227 person-years. Height was not associated with CRC for either men (per 5-cm increment, hazard ratio (HR) = 1.00, 95% confidence interval (CI): 0.91, 1.11) or women (per 5-cm increment, HR = 1.01, 95% CI: 0.92, 1.11), nor was height associated with EC (per 5-cm increment, HR = 1.08, 95% CI: 0.94, 1.24). Hence, we observed no evidence for an association of height with either CRC or EC among persons with LS.

Gynecological Surveillance and Surgery Outcomes in Dutch Lynch Syndrome Carriers

Simple Summary

Female Lynch syndrome (LS) carriers have an increased risk to develop endometrial and ovarian cancer. In the Netherlands, carriers are therefore advised annual gynecological surveillance and eventually, risk-reducing surgery. Global gynecological LS surveillance guidelines are scarce and based on limited evidence. These are, however, warranted to offer accurate surveillance. To provide more insight into surveillance outcomes, this study assessed outcomes of gynecological surveillance and risk-reducing surgery in 164 LS carriers diagnosed in our center, with a median follow-up of 5.6 years per carrier. Although most surveillance visits happened within an advised timeframe, we observed large variability in how gynecological surveillance visits were performed. This finding stresses the need for development of clear and evidence-based guidelines. Endometrial cancers identified at surveillance were all found in early stage, mostly symptomatic, questioning surveillance benefit. Large, prospective studies should assess to what extent current LS surveillance programs contribute to early detection of gynecological tumors.

Abstract

Lynch syndrome (LS) is caused by pathogenic germline variants in DNA mismatch repair (MMR) genes, predisposing female carriers for endometrial cancer (EC) and ovarian cancer (OC). Since gynecological LS surveillance guidelines are based on little evidence, we assessed its outcomes. Data regarding gynecological tumors, surveillance, and (risk-reducing) surgery were collected from female LS carriers diagnosed in our center since 1993. Of 505 female carriers, 104 had a gynecological malignancy prior to genetic LS diagnosis. Of 264 carriers eligible for gynecological management, 164 carriers gave informed consent and had available surveillance data: 38 MLH1, 25 MSH2, 82 MSH6, and 19 PMS2 carriers (median follow-up 5.6 years). Surveillance intervals were within advised time in >80%. Transvaginal ultrasound, endometrial sampling, and CA125 measurements were performed in 76.8%, 35.9%, and 40.6%, respectively. Four symptomatic ECs, one symptomatic OC, and one asymptomatic EC were diagnosed. Endometrial hyperplasia was found in eight carriers, of whom three were symptomatic. Risk-reducing surgery was performed in 73 (45.5%) carriers (median age 51 years), revealing two asymptomatic ECs. All ECs were diagnosed in FIGO I. Gynecological management in LS carriers varied largely, stressing the need for uniform, evidence-based guidelines. Most ECs presented early and symptomatically, questioning the surveillance benefit in its current form.

Prevalence of Lynch syndrome in women with mismatch repair-deficient ovarian cancer

BACKGROUND

There are limited data on the prevalence of Lynch syndrome (LS) in women with primary ovarian cancer with mismatch repair deficiency (MMR-D) by immunohistochemistry (IHC).

MATERIALS AND METHODS

Three hundred and eight cases of primary ovarian, fallopian, and peritoneal cancer between January 2012 and December 2019 were evaluated for MMR-D by IHC. The incidence of LS in this cohort was evaluated.

RESULTS

MMR-D by IHC was identified in 16 of 308 (5.2%) (95% CI: 3.2%-8.3%) primary ovarian-related cancers. Most cases with MMR-D were endometrioid (n = 11, 68.7%); (95% CI: 44.2%-86.1%). MSH2/MSH6 protein loss was detected in eight cases (50.0%); (95% CI: 28.0%-72.0%) and MLH1/PMS2 protein loss was detected in four cases (25.0%); (95% CI: 9.7%-50.0%). MSH6 protein loss was detected in two cases (12.5%); (95% CI: 2.2%-37.3%) and PMS2 protein loss was detected in two cases (12.5%); (95% CI: 2.2%-37.3%). All four cases with MLH1/PMS2 protein loss had MLH1 promotor hypermethylation. All 12 women with ovarian cancer suggestive of LS underwent germline testing and 8 (66.6%); (95% CI: 38.8%-86.5%) were confirmed to have LS.

CONCLUSIONS

Most ovarian cancers with somatic MMR-D were confirmed to have LS in this cohort. Germline testing for LS in addition to BRCA1/2 for all women with an epithelial ovarian cancer would be efficient and would approach 100% sensitivity for identifying Lynch syndrome. Utilization of a multigene panel should also be considered, given the additional non-Lynch germline mutation identified in this cohort.

DNA Repair Syndromes and Cancer: Insights Into Genetics and Phenotype Patterns

DNA damage response is essential to human physiology. A broad spectrum of pathologies are displayed by individuals carrying monoallelic or biallelic loss-of-function mutations in DNA damage repair genes. DNA repair syndromes with biallelic disturbance of essential DNA damage response pathways manifest early in life with multi-systemic involvement and a high propensity for hematologic and solid cancers, as well as bone marrow failure. In this review, we describe classic biallelic DNA repair cancer syndromes arising from faulty single- and double-strand DNA break repair, as well as dysfunctional DNA helicases. These clinical entities include xeroderma pigmentosum, constitutional mismatch repair deficiency, ataxia telangiectasia, Nijmegen breakage syndrome, deficiencies of DNA ligase IV, NHEJ/Cernunnos, and ERCC6L2, as well as Bloom, Werner, and Rothmund-Thompson syndromes. To give an in-depth understanding of these disorders, we provide historical overview and discuss the interplay between complex biology and heterogeneous clinical manifestations.

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.

Diet quality and colorectal tumor risk in persons with Lynch syndrome

BACKGROUND

Persons with Lynch syndrome (LS) have an increased risk of developing colorectal tumors (CRTs). Adherence to diet quality indices associated with colorectal cancer (CRC) risk in the general population has not been studied before in LS.

METHODS

Dietary habits of 490 participants with LS from a prospective cohort study was collected using a food frequency questionnaire. The Dutch Healthy Diet index 2015 (DHD15-index) and Dietary Approaches to Stop Hypertension (DASH) were used to score food-based diet quality. Diet quality scores were divided into tertiles where a higher tertile reflects a higher diet quality. Multivariable Cox proportional hazard regression models were used to estimate the association between the DHD15-index, DASH score and CRT risk.

RESULTS

During a median follow-up time of 53.4 months, 210 participants (42.9%) developed CRTs. The DHD-index and DASH score were not associated with CRT risk; hazard ratios for highest vs. lowest tertile were 1.00 (95% Confidence Interval (CI): 0.67-1.48) and 1.11 (95% CI: 0.74-1.69), respectively. No linear trends across the DHD-index and DASH score tertiles were observed (P-trend = 0.97 and 0.83 respectively).

CONCLUSION

In contrast to observations in the general population, no evidence for an association between the food-based DHD15-index or DASH score and CRT risk was observed in persons with LS. Further studies are needed investigating the association between diet quality and mechanisms leading to the development of LS-associated tumors.

Genetic Susceptibility to Endometrial Cancer: Risk Factors and Clinical Management

Endometrial cancer (EC) is the most common cancer affecting the female reproductive organs in higher-income states. Apart from reproductive factors and excess weight, genetic predisposition is increasingly recognized as a major factor in endometrial cancer risk. Endometrial cancer is genetically heterogeneous: while a subgroup of patients belongs to cancer predisposition syndromes (most notably the Lynch Syndrome) with high to intermediate lifetime risks, there are also several common genomic polymorphisms contributing to the spectrum of germline predispositions. Germline variants and somatic events may act in concert to modulate the molecular evolution of the tumor, where mismatch-repair deficiency is common in endometrioid endometrial tumors whereas homologous recombinational repair deficiency has been described for non-endometrioid endometrial tumors. In this review, we will survey the currently known genomic predispositions for endometrial cancer and discuss their relevance for clinical management in terms of counseling, screening and novel treatments.