Adenomatous polyps of the appendix frequently had APC, KRAS and TP53 mutations and were morphologically and molecularly similar to adenomatous polyps of the colorectum.
Germline mutations in the adenomatous polyposis coli (APC) gene cause familial adenomatous polyposis (FAP), an autosomal dominant disease characterized by hundreds to thousands of adenomatous polyps in the colon and rectum, with progression to colorectal cancer.
Biallelic mutations for Y165C and/or G382D were not found in any of those undergoing screening colonoscopy with 0-3 polyps (n = 400), in those APC-negative patients with <20 adenomatous polyps (n = 26), or in those with CRC who were older than 50 years (n = 328).
Using real-time quantitative PCR, we demonstrated that several genes previously implicated in human colon cancer undergo altered expression in the APC(min) mouse adenomatous polyp, a precursor of cancer, as well as in normal-appearing surrounding mucosa.
In this study, we have confirmed and refined the LOH-associated region in colorectal FAP: allelic loss in adenomatous polyps tended to occur when the germline mutation lay in the region of the APC gene between the first and second beta-catenin degradation repeats (codons 1285-1378).
The germ-line missense variant of the APC gene, E1317Q, has been proposed to confer a risk for colonic adenomatous polyps (adenomas), but not for CRCs in the general population.
This last mutation occurs in the EB1-binding domain of the APC protein and segregates in four relatives of the patient with three of them presenting 2-3 adenomatous polyps.
Among the genetic defects associated with CRC, the APCI1307K mutation has been detected nearly exclusively in individuals of Ashkenazi Jewish (AJ) origin, occurring in 6%-7% of the AJ general population and in 10%-28% of AJ with a either a personal or family history of CRC or adenomatous polyps.
Germline mutations (nonsense, frameshift) of APC are associated with familial adenomatous polyposis, an autosomal dominant syndrome, clinically characterized by young onset, hundreds of adenomatous polyps in the colon, and increased risk for extracolonic tumors.
The observation that the attenuated form of adenomatous polyposis coli (AAPC) has a different mutational spectrum in both the adenomatous polyp and the carcinoma than the classical form of APC has led to the hypothesis that AAPC alleles retain some residual APC activity associated with a greatly reduced number of polyps.
Furthermore, the adenomatous polyposis coli (APC) gene on Chr 5, mutated somatically in adenomatous polyps and mutated in the germline of patients with familial adenomatous polyposis, is not linked to hereditary juvenile polyposis.
Desmoid tumors are usually a complication of familial adenomatous polyposis, a predisposition to the early development of premalignant adenomatous polyps in the colorectum due to chain-terminating mutations of the APC gene.
Since some gastric cancers are considered to originate from the intestinal metaplasia, it is likely that the adenomatous polyposis coli (APC) gene, the mutation of which causes adenomatous polyps in the colon, is associated with carcinogenesis of gastric cancer.
Differential labeling by monoclonal antibodies Adnab-9 and anti-alpha-defensin 5 based on the distribution and adenomatous tissue content of colonic polyps.
Adenomatous polyps of the appendix frequently had APC, KRAS and TP53 mutations and were morphologically and molecularly similar to adenomatous polyps of the colorectum.
Contribution of bi-allelic germline MUTYH mutations to early-onset and familial colorectal cancer and to low number of adenomatous polyps: case-series and literature review.