In addition, we studied the hMLH1, hMSH2, hMSH3, and hMSH6 promoter methylation and MSI status of those endometrial carcinomas with synchronous hyperplasias and those without them.
Recently, a link has been established between hMSH6 mutations and 'atypical' hereditary non-polyposis colon cancer (HNPCC) with an increased incidence of endometrial cancers.
These results demonstrate a marked difference between hereditary nonpolyposis colorectal cancer-related CRCs and ECs and suggest that the development of the latter tumors is selectively associated with the MSH2/MSH6 protein complex deficiency.
Moreover, the mean age of onset of both colorectal cancer (MSH6 v MSH2/MLH1 = 55 years v 44/41 years) and endometrial carcinomas (MSH6 v MSH2/MLH1 = 55 years v 49/48 years) is delayed.
Microsatellite instability positive ECs frequently are associated with frameshift mutations in coding mononucleotide tracts in IGFIIR, BAX, hMSH6, and hMSH3.
We therefore wanted to investigate the pattern of hMSH2 and hMSH6 expression in a prospective and population-based series of endometrial carcinomas with known hMLH1 expression and MSI status.
Israeli patients with early onset (age under 50 years) (n = 44) and familial nonsyndromic (n = 23) CRC, and women with familial clustering of EC or CRC (n = 12), and those diagnosed with EC at, or under, the age of 50 years (n = 5) were genotyped for germ-line mutations within the hMSH6 gene.
Hereditary nonpolyposis colorectal cancer (HNPCC)-associated second and third cancers were analyzed for MSI and MSH2, MSH6, and MLH1 expression for comparison with the corresponding endometrial cancers.
MSH6 mutation carriers have later age of onset of both colorectal cancer (62 vs. 51 years) and endometrial cancer (58 vs. 48 years) and a larger proportion of endometrial cancer than MLH1 or MSH2 mutation carriers.
MSH6 mutation carriers have later age of onset of both colorectal cancer (62 vs. 51 years) and endometrial cancer (58 vs. 48 years) and a larger proportion of endometrial cancer than MLH1 or MSH2 mutation carriers.
The aim of this study was to investigate the penetrance and expressivity of MSH6 mutations in kindreds ascertained through endometrial cancer probands unselected for family history.
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.
In female MSH6 mutation carriers, the risk for colorectal cancer was significantly lower (P = 0.0049) and the risk for endometrial cancer significantly higher (P = 0.02) than in MLH1 and MSH2 mutation carriers.