Lynch syndrome is a cancer-predisposing syndrome inherited in an autosomal-dominant manner, wherein colon cancer and endometrial cancer develop frequently in the family, it results from a loss-of-function mutation in one of four different genes (MLH1, MSH2, MSH6, and PMS2) encoding mismatch repair proteins.
Mismatch repair (MMR) deficiency due to MLH1 gene methylation is one of the most common molecular alterations in endometrial cancer, occurring in 15% to 20% of cases.
This study aimed to determine the in vitro and in vivo properties of sixteen frequently used endometrial cancer (EC) cell lines, including the cell proliferation rate, morphology, hormone receptor expression patterns, PTEN, hMLH1 expression, p53 mutation, karyotype, and tumorigenicity in mouse xenograt model.
The aim of this study was to evaluate outcomes of MMR immunohistochemistry (IHC), mutL homolog 1 (MLH1) methylation, and microsatellite instability (MSI) analysis among patients with endometrial cancer.
The three pathogenic variants included two colorectal cancers with MLH1 loss and high MSI and one endometrial cancer with MSH6 loss and microsatellite stability.
Because MLH1 promoter hypermethylation was detected in endometrial cancer tissue samples, the epigenetic silencing of MLH1 was suspected as the cause of the protein loss.
We identified 99 patients diagnosed with endometrioid EC and performed IHC for MMRPs MLH1, MSH2, MSH6, and PMS2 on their diagnostic EMB/C and paired hysterectomy specimen.
Extensive hypermethylation of the MLH1 promoter was observed in 69.6% ECs with MLH1 deficiency and 3.5% with MMR proficiency, but in none of the ECs with loss of other MMR genes (P < .0001).
A simple combination of morphological and immunohistochemical characteristics (tumour type, grade, peritumoral lymphocytes, MLH1, and p53 expression) can assist in prescreening for POLE exonuclease domain mutations in EC, increasing the probability of a mutation being detected from 7% to 33%.
This study sought to examine the clinicopathologic features and immune markers associated with the DNA mismatch repair (MMR) status and MLH1 promoter methylation status of endometrial cancer patients.
LS is caused by heterozygous germline variants of MSH2, MSH6, PMS2 and MLH1 and characterized by an increased risk of developing colorectal and endometrial cancer at adult age.
To evaluate the expression of four genetic markers (PTEN, BCL2, MLH1, and CTNNB1), linked to endometrial carcinogenesis, in endometrial polyps of patients with and without postmenopausal bleeding in order to determine whether symptomatic endometrial polyps have a genetic phenotype similar to that of endometrial cancer.
MLH1 methylation analysis identifies women with tumor MLH1 loss who likely have sporadic endometrial cancer and do not need heightened cancer prevention surveillance.
Here we describe our institution's experience with a prospective universal screening protocol in which all ECs resected over a period of 19 months (n=242) were screened for MLH1, PMS2, MSH2, and MSH6 deficiencies using IHC, followed by MLH1 promoter methylation testing when appropriate.
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.
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.
Lynch syndrome is a hereditary cancer syndrome associated with high risks of colorectal and endometrial cancer that is caused by pathogenic variants in the mismatch repair genes (MLH1, MSH2, MSH6, PMS2, EPCAM).
A total of 253 individuals with an MMRD CRC or EC from one institution were included for analysis in one of four groups: LS; MMRD+/germ-line-; MMRD tumor with variant of uncertain significance (MMRD+/VUS); and sporadic MSI-H (MMRD tumor with MLH1 promoter hypermethylation or BRAF mutation).
MSI is also observed in about 15 % of sporadic colorectal cancer (CRC), gastric cancer (GC), and endometrial cancer (EC), and at lower frequencies in other cancers, often in association with hypermethylation of the MLH1 gene.