Presentation Title
Detecting Microsatellite Instabilities to Diagnose Lynch Syndrome in Colorectal Cancer Patients
Document Type
Poster Session
Department
Biological Sciences
Faculty Mentor
Daniel Moore, PhD
Abstract
Detection of microsatellite instabilities (MSI) in colorectal cancer (CRC) patients aids in the diagnosis of Lynch Syndrome. Early diagnosis allows the patient and their family to take preventative measures. Lynch Syndrome is a hereditary disease caused by loss-of-function germline mutations in genes that encode mismatch repair (MMR) factors and is one of the most common cancer susceptibility syndromes. Individuals with Lynch Syndrome have a 50-70% lifetime risk of colorectal cancer, 40-60% risk of endometrial cancer, and increased risk for several other malignancies. Lynch Syndrome has led to CRC in patients beginning as early as 20 years old, with the average age of affected individuals being 46 years old. Microsatellite instabilities was the first DNA marker available to identify a hereditary CRC and led to the realization that MSI are a result of defects in the MMR system. Screening for Lynch Syndrome is either carried out by polymerase chain reaction (PCR) of MSI or immunohistochemistry (IHC) testing. There is some debate which method is most effective, and this literature review will look more closely at this debate about testing methodology. Regions of the MMR genes are also sequenced to look for mutations that may help in diagnosis. There has been a steady increase in Lynch Syndrome tumor screening programs since 2000 and institutions are rapidly adopting a universal screening approach to find the best methodology for testing and interpreting results from CRC patients.
Open Access?
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Detecting Microsatellite Instabilities to Diagnose Lynch Syndrome in Colorectal Cancer Patients
Detection of microsatellite instabilities (MSI) in colorectal cancer (CRC) patients aids in the diagnosis of Lynch Syndrome. Early diagnosis allows the patient and their family to take preventative measures. Lynch Syndrome is a hereditary disease caused by loss-of-function germline mutations in genes that encode mismatch repair (MMR) factors and is one of the most common cancer susceptibility syndromes. Individuals with Lynch Syndrome have a 50-70% lifetime risk of colorectal cancer, 40-60% risk of endometrial cancer, and increased risk for several other malignancies. Lynch Syndrome has led to CRC in patients beginning as early as 20 years old, with the average age of affected individuals being 46 years old. Microsatellite instabilities was the first DNA marker available to identify a hereditary CRC and led to the realization that MSI are a result of defects in the MMR system. Screening for Lynch Syndrome is either carried out by polymerase chain reaction (PCR) of MSI or immunohistochemistry (IHC) testing. There is some debate which method is most effective, and this literature review will look more closely at this debate about testing methodology. Regions of the MMR genes are also sequenced to look for mutations that may help in diagnosis. There has been a steady increase in Lynch Syndrome tumor screening programs since 2000 and institutions are rapidly adopting a universal screening approach to find the best methodology for testing and interpreting results from CRC patients.
