Risk of metachronous CRC was estimated for 382 MMR gene mutation carriers (172 MLH1, 167 MSH2, 23 MSH6 and 20 PMS2) from the Colon Cancer Family Registry, who had surgery for their first colon cancer, using retrospective cohort analysis.
Deleterious germ-line variants involving the DNA mismatch repair (MMR) genes have been identified as the cause of the hereditary nonpolyposis colorectal cancer syndrome known as the Lynch syndrome, but in numerous familial clusters of colon cancer, the cause remains obscure.
We studied two of these genomic defects-mismatch repair deficiency (MMR-D) and loss of heterozygosity at chromosomal location 18q (18qLOH)-in patients enrolled onto two phase III cooperative group trials for treatment of potentially curable colon cancer.
We hypothesise a model in which variants of the MSH3 gene behave as low-risk alleles that contribute to the risk of colon cancer in Lynch families, mostly with other low-risk alleles of MMR genes.
This study reports a case series of de novo mutations in MMR genes and estimates the frequency of de novo mutation in MMR genes using the Colon Cancer Family Registry.
A retrospective cohort study was performed on women diagnosed with CRC with a germline mutation in a mismatch repair (MMR) gene (Lynch syndrome cases), and women with microsatellite stable (MSS) CRC who were not known to carry a germline mutation (non-Lynch cases), identified from the Colon Cancer Family Registry.
In particular, gene instability caused by decreased expression of the hMLH1 gene, a DNA mismatch repair (MMR) gene, may be linked to the activating BRAF V600E point mutation in sporadic colon cancer.
Less understood is the risk of colon cancer associated with common polymorphisms in MMR genes and the potential interacting role of lifestyle factors known to damage DNA.
Current theories of malignant transformation postulate that development of colon cancer is related to 2 main pathways; the loss of heterozygosity pathway, which is usually due to a defect in the adenomatous polyposis coli APC gene and microsatellite instability, which is usually due to a defect in mismatch repair MMR genes.
Hereditary non-polyposis colorectal cancer (HNPCC), the most common hereditary colon cancer syndrome, is a dominant disorder caused by germline defects in mismatch repair (MMR) genes.
Owing to a tight correlation between MSI-high, inactivating mutations of MMR genes and MMR protein expression in colon cancer, MMR protein expression commonly is used as a marker for MSI.
In this report, we show that such hybrid cell lines can also be a valuable tool in the study of the mutated MMR proteins, in particular the variants found in hereditary nonpolyposis colon cancer families that carry missense mutations and where it is unclear whether they predispose to colon cancer.
Colon cancer was more frequently located in the proximal colon and showed an earlier age at onset in families with MMR gene mutation or with MSI than in families with stable tumors.
To investigate the prevalence of the microsatellite instability related to mismatch repair (MMR) gene defects using a panel of six microsatellite markers, as recommended by a recent workshop on microsatellite instability in colon cancer, because it is still unclear whether abnormalities in DNA MMR genes are involved in transitional cell carcinoma (TCC) of the bladder.
Germline mutations of MMR genes cause susceptibility to a hereditary form of colon cancer, hereditary nonpolyposis colon cancer (HNPCC), which represents one of the most common syndromes associated with cancer predisposition in man.