Germline MLH1 Mutations Are Frequently Identified in Lynch Syndrome Patients With Colorectal and Endometrial Carcinoma Demonstrating Isolated Loss of PMS2 Immunohistochemical Expression.
Among microsatellite instability high endometrial cancers with minimal microsatellite shift, 65% (17/26) had combined MLH1 and PMS2 loss, 8% (2/26) had combined MSH2 and MSH6 loss, 13% (3/26) had MSH6 loss and 15% (4/26) had loss of PMS2 by immunohistochemistry.
HNPCC is an autosomal dominantly inherited cancer-susceptibility syndrome that confers an increased risk for colorectal cancer and endometrial cancer at a young age.
We investigated the role that methylation of the MLH1 DNA mismatch repair gene plays in the genesis of MSI in a large series of sporadic endometrial cancers.
Combined microsatellite instability (MSI) and immunohistochemical analysis of MLH1 and MSH2 predicted the presence of a mutation in MSH2 when she had endometrial hyperplasia without atypia 7 months before the diagnosis of endometrial cancer.
In 2015, our institution implemented universal screening of endometrial cancer (EC) hysterectomy specimens by mismatch repair immunohistochemistry (IHC) with reflex MLH1 promoter hypermethylation analysis for tumors with loss of MLH1/PMS2 expression.
In this study, we investigated the frequency of BAF250a immunohistochemical loss in a cohort of high-grade endometrial cancers (n=190) and correlated it with mismatch repair (hMLH1, hMSH2, hMSH6, and hPMS2) and p53 protein expression.
IDO immunohistochemistry was performed on 60 endometrial carcinomas (20 Lynch syndrome (LS)-associated, 20 MLH1 promoter hypermethylated, and 20 mismatch repair-intact).
Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant disorder predisposing to predominantly colorectal cancer (CRC) and endometrial cancer frequently due to germline mutations in DNA mismatch repair (MMR) genes, mainly MLH1, MSH2 and also MSH6 in families seen to demonstrate an excess of endometrial cancer.
Combined Microsatellite Instability, MLH1 Methylation Analysis, and Immunohistochemistry for Lynch Syndrome Screening in Endometrial Cancers From GOG210: An NRG Oncology and Gynecologic Oncology Group Study.
Purpose Most existing literature describes Lynch syndrome (LS) as a hereditary syndrome leading to high risks of colorectal cancer (CRC) and endometrial cancer mainly as a result of mutations in MLH1 and MSH2.
Epigenetic silencing of MLH1 in endometrial cancers is associated with larger tumor volume, increased rate of lymph node positivity and reduced recurrence-free survival.
Modalities to detect ECs for the possibility of HNPCC include microsatellite instability assay, immunohistochemistry for DNA mismatch repair proteins, MLH1 promoter hypermethylation assay and mutational analysis of DNA mismatch repair genes.
We present an instructive case of FIGO grade 1 endometrioid endometrial carcinoma with a biphasic morphology, corresponding to subclonal loss of mismatch repair proteins (MMRP) MLH1 and PMS2 by immunohistochemistry and subclonal microsatellite instability.
Whereas some ECs are due to germline Lynch syndrome (LS)-associated mutations, the majority demonstrate sporadic MLH1 promoter hypermethylation (MLH1hm).
Remarkably, among MLH1 mutation carriers, 54% of ECs (21 of 39), but none of the CRCs (0 of 32), lacked the MSH2 and/or MSH6 protein in addition to lacking MLH1 protein expression.
A mutational analysis of three DNA mismatch repair (MMR) genes (hMLH1, hMSH2 and hMSH6) in patients with endometrial cancer who meet our criteria for familial predisposition to HNPCC-associated endometrial cancers was performed.