Dysphagia in Lynch syndrome

Microsatellite instability in noncolorectal and nonendometrial malignancies in patients with Lynch syndrome

BACKGROUND

Individuals with Lynch syndrome are at increased hereditary risk of colorectal and endometrial carcinomas with microsatellite instability (MSI-H) and mismatch repair-deficiency (dMMR), which make these tumors vulnerable to therapy with immune checkpoint inhibitors. Our aim is to assess how often other tumor types in these individuals share these characteristics.

METHODS

We retrieved the full tumor history of a historical clinic-based cohort of 1745 individuals with Lynch syndrome and calculated the standardized incidence ratio for all tumor types. MSI status, somatic second hit alterations, and immunohistochemistry-based MMR status were analyzed in 236 noncolorectal and nonendometrial malignant tumors.

RESULTS

In individuals with Lynch syndrome MSI-H/dMMR occurred both in Lynch-spectrum and in non-Lynch-spectrum malignancies (85% vs 37%, P < .01). MSI-H/dMMR malignancies were found in nearly all non-Lynch-spectrum tumor types. Almost all breast carcinomas had medullary features, and most of them were MSI-H/dMMR. Breast carcinoma with medullary features were shown to be associated with Lynch syndrome (standardized incidence ratio = 38.8, 95% confidence interval = 16.7 to 76.5).

CONCLUSIONS

In individuals with Lynch syndrome, MSI-H/dMMR occurs in more than one-half of the malignancies other than colorectal and endometrial carcinomas, including tumor types without increased incidence. The Lynch-spectrum tumors should be expanded to breast carcinomas with medullary features. All malignancies in patients with Lynch syndrome, independent of subtype, should be tested for MSI-H/dMMR in case therapy with immune checkpoint inhibitors is considered. Moreover, Lynch syndrome should be considered an underlying cause of all MSI-H/dMMR malignancies other than colorectal and endometrial carcinomas.

Prevalence and risk factors of barrett's esophagus in lynch syndrome

Lynch syndrome (LS), the most common hereditary cause of colorectal cancer, predisposes to upper gastrointestinal neoplasia. The prevalence of Barrett's esophagus (BE) is elevated in some hereditary gastrointestinal cancer syndromes but has not been systematically evaluated in LS. We assessed the prevalence of BE, BE-related dysplasia, esophageal adenocarcinoma (EAC), and factors associated with BE in LS. Asymptomatic patients with a germline pathogenic variant (PV) in the DNA mismatch repair (MMR) genes undergoing EGD for LS surveillance were identified from a hereditary colorectal cancer registry. We assessed the prevalence of BE and compared demographic, clinical, and endoscopic factors in LS patients with and without BE by logistic regression analysis. 323 patients were included. 21 patients (6.5%) were diagnosed with BE including 38% of females and 33% without gastroesophageal reflux disease (GERD). Dysplasia was diagnosed in two patients (9.5%) and EAC in one (4.8%) patient. Factors associated with BE included male gender (OR 3.00, 1.21-7.46), age at last LS EGD (OR 1.04, 1.01-1.08), presence of hiatal hernia (OR 20.09, 4.57-88.23), hiatal hernia > 3 cm (OR 11.25, 2.41-51.94), and GERD (OR 3.39, 1.32-8.67). No MMR PV was associated with BE. BE was diagnosed in 1 of 15 patients undergoing EGD surveillance for LS and nearly 10% had dysplasia including one EAC. Risk factors associated with BE in LS are similar to those established for BE in the general population. More studies are needed to evaluate if an association between BE and LS exists.

The Approach to Performance of Quality Upper Endoscopy in Lynch Syndrome (QUELS): An International Expert Statement

Strong evidence demonstrates the protective benefit of frequent colonoscopy surveillance for colorectal cancer prevention in Lynch Syndrome (LS) and is endorsed by many guidelines. Until recently, the evidence supporting the utility of upper endoscopy [esophagogastroduodenoscopy (EGD)] for upper gastrointestinal (UGI) cancer surveillance was limited. Over the last 3 years, multiple studies have demonstrated that EGD surveillance in LS is associated with the detection of both precancerous lesions and early-stage UGI cancers. On the basis of the emerging favorable evidence derived from EGD surveillance programs, the 2022 National Comprehensive Cancer Network (NCCN) Guidelines for LS recommend UGI surveillance with EGD starting between age 30 and 40 years with repeat EGDs every 2 to 4 years, preferably in conjunction with colonoscopy, in all patients with a germline pathogenic variant (PV) in MLH1, MSH2, EPCAM, and MSH6 and, because of the lack of data, consideration in PMS2. Standardization of the approach to performing EGD surveillance in LS and reporting clinically actionable findings is requisite for both improving quality and understanding the cost efficiency and outcomes of patients undergoing EGD as a surveillance tool. Accordingly, the primary objective of this Quality of Upper Endoscopy in Lynch Syndrome (QUELS) statement is to articulate a framework for standardizing the approach to performing and reporting EGD findings in patients with LS by introducing emerging quality metrics. The recommendations presented herein were developed from available evidence and consensus-based expert opinion and provide a practical approach for clinicians applying EGD surveillance in accordance with the most recent and existing LS guidelines.

Upper Gastrointestinal Cancer Surveillance in Lynch Syndrome

Simple Summary

Lynch syndrome is the most common cause of hereditary colorectal cancer, but is also associated with increased extracolonic cancer risk, including upper gastrointestinal cancers. While there is agreement regarding the benefit of frequent colonoscopic surveillance in Lynch syndrome, there remains a lack of consensus on the use of upper gastrointestinal cancer surveillance. Here, we review the upper gastrointestinal cancer risks in Lynch syndrome, the varying guideline recommendations in this area, and the published outcomes of upper gastrointestinal cancer surveillance in this high-risk population. Finally, we highlight ongoing controversies in upper gastrointestinal cancer surveillance and opine on how upper gastrointestinal cancer surveillance can be incorporated into a Lynch syndrome risk management program. Upper gastrointestinal cancer surveillance is an increasingly studied area of risk management in Lynch syndrome, and continued research will be vital in determining how to best incorporate this surveillance in these high-risk patients.

Abstract

Lynch syndrome is a common hereditary cancer predisposition syndrome associated with increased digestive cancer risk including colorectal, gastric, and duodenal cancers. While colorectal cancer surveillance is widely accepted to be an important part of a comprehensive Lynch syndrome risk management plan, the use of upper gastrointestinal cancer surveillance in Lynch syndrome remains more controversial. Currently, upper gastrointestinal cancer surveillance guidelines for Lynch syndrome vary widely, and there is no consensus on who should undergo upper gastrointestinal cancer surveillance, how surveillance should be performed, the age at which to initiate surveillance, or how often individuals with Lynch syndrome should undergo upper gastrointestinal cancer surveillance. Fortunately, research groups around the world have been focusing on upper gastrointestinal cancer surveillance in Lynch syndrome, and recent evidence in this field has demonstrated that upper gastrointestinal cancer surveillance can be performed with identification of precancerous lesions as well as early-stage upper gastrointestinal cancers. In this manuscript, we review the upper gastrointestinal cancer risks in Lynch syndrome, differing guideline recommendations for surveillance, outcomes of upper gastrointestinal cancer surveillance, and controversies in the field, and we provide a framework based on our collective experience with which to incorporate upper gastrointestinal cancer surveillance into a risk management program for individuals with Lynch syndrome.

Using Immunohistochemistry to Expand the Spectrum of Lynch Syndrome-Related Tumors

The most common genetic and molecular process leading to sporadic colorectal cancer is chromosomal instability. By contrast, mismatch repair deficiency, which results in high levels of microsatellite instability or lack of mismatch repair (MMR) protein expression on immunohistochemistry (IHC), is the predominant cancer pathway in patients with Lynch syndrome (LS). Importantly, patients with LS may still develop sporadic tumors through chromosomal instability. Testing tumors with IHC staining helps expand the spectrum of LS-related tumors. In this series, we describe 4 cancers in patients with LS that are not typical of the syndrome. Lack of MMR protein expression on IHC staining confirmed that 2 cancers are related to LS, expanding the spectrum of LS-related tumors, and the presence of MMR protein expression on IHC in the other 2 cases confirmed that they were sporadic and not related to mismatch repair deficiency and, thus, not related to LS.

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.