Duodenal Adenomas and Cancer in MUTYH-associated Polyposis: An International Cohort Study

Although duodenal adenomas and cancer appear to occur significantly less frequently in autosomal recessive MUTYH-associated polyposis (MAP) than in autosomal dominant familial adenomatous polyposis (FAP),1 current guidelines recommend similar endoscopic surveillance for both disorders.2-4 This involves gastro-duodenoscopy starting at 25 to 35 years of age and repeated at intervals determined by Spigelman staging based on the number, size, histological type and degree of dysplasia of adenomas, and by ampullary staging. Case reports of duodenal cancers in MAP suggest that they may develop in the absence of advanced Spigelman stage benign disease and even without coexisting adenomas.1 Recent molecular analyses suggest thatMAPduodenal adenomashave a higher mutational burden than FAP adenomas and are more likely to harbor oncogenic drivermutations, such as those in KRAS.5 These apparent differences in the biology and natural history of duodenal polyposis in FAP and MAP challenge the assumption that the same surveillance should be applied in both conditions

Colorectal surveillance outcomes from an institutional longitudinal cohort of lynch syndrome carriers

ObjectiveLynch Syndrome (LS) carriers have a significantly increased risk of developing colorectal cancer (CRC) during their lifetimes. Further stratification of this patient population may help in identifying additional risk factors that predispose to colorectal carcinogenesis. In most LS patients CRC may arise from adenomas, although an alternative non-polypoid carcinogenesis pathway has been proposed for PMS2 carriers. Using data from our institutional LS cohort, our aim was to describe our current colorectal screening outcomes with a focus on the incidence of adenomas in the context of different MMR genotypes and patient demographics such as gender, race, and ethnicity.DesignWe collected demographics, genetic, colonoscopy, and pathology results from a total of 163 LS carriers who obtained regular screening care at MD Anderson Cancer Center. Data were extracted from the electronic health records into a REDCap database for analysis. Logistic regressions were performed to measure the association between MMR variants and the likelihood of adenomas, advanced adenomas, and CRC. Then, we analyzed the cumulative incidences of these outcomes for the first 36 months following enrollment using Kaplan-Meier incidence curves, and Cox proportional hazard regressions.ResultsOn multivariate analysis, age (≥45 years old) was associated with an increased risk of developing adenomas (P=0.034). Patients with a prior or active cancer status were less likely to develop adenomas (P=0.015), despite of the lack of association between surgical history with this outcome (P=0.868). We found no statistically significant difference in likelihood of adenoma development between MLH1 and MSH2/EPCAM, MSH6, and PMS2 carriers. Moreover, we observed no statistically significant difference in the likelihood of advanced adenomas or CRC for any measured covariates. On Cox proportional hazard, compared to MLH1 carriers, the incidence of adenomas was highest among MSH2/EPCAM carriers during for the first 36-months of follow-up (P<0.001). We observed a non-statistically significant trend for Hispanics having a higher and earlier cumulative incidence of adenomas compared to non-Hispanics (P=0.073). No MMR carrier was more likely to develop advanced adenomas. No difference in the incidence of CRC by MMR gene (P=0.198).ConclusionScreening recommendations for CRC in LS patients should be based on specific MMR variants and should also be tailored to consider patient demographics

Risk assessment and genetic counseling for Lynch syndrome – Practice resource of the National Society of Genetic Counselors and the Collaborative Group of the Americas on Inherited Gastrointestinal Cancer

Identifying individuals who have Lynch syndrome involves a complex diagnostic workup that includes taking a detailed family history and a combination of various tests such as immunohistochemistry and/or molecular which may be germline and/or somatic. The National Society of Genetic Counselors and the Collaborative Group of the Americas on Inherited Gastrointestinal Cancer have come together to publish this practice resource for the evaluation of Lynch syndrome. The purpose of this practice resource was to provide guidance and a testing algorithm for Lynch syndrome as well as recommendations on when to offer testing. This practice resource does not replace a consultation with a genetics professional. This practice resource includes explanations in support of this and a summary of background data. While this practice resource is not intended to serve as a review of Lynch syndrome, it includes a discussion of background information and cites a number of key publications which should be reviewed for a more in-depth understanding. This practice resource is intended for genetic counselors, geneticists, gastroenterologists, surgeons, medical oncologists, obstetricians and gynecologists, nurses, and other healthcare providers who evaluate patients for Lynch syndrome.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/172941/1/jgc41546.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/172941/2/jgc41546_am.pd

Impact of Hispanic Ethnicity on Colorectal Cancer Surveillance Outcomes and Management in an Institutional Longitudinal Cohort of Lynch Syndrome Patients

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