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We report the existence of both germline and somatic mutations of the APC gene in thyroid carcinomas from familial adenomatous polyposis (FAP) patients. One papillary thyroid carcinoma from a 210-year-old woman, with germline mutation of the APC gene (TCA to TGA at codon 1110), showed a somatic mutation of AAAAC deletion between codons 1060 and 1063. Another somatic mutation of CAG to TAG at codon 886 was also found in one of multiple thyroid carcinomas from a 26-year-old woman with attenuated FAP and germline mutation at codon 175 (C deletion). This is the first evidence that total absence of the normal function of the APC gene is involved in development of thyroid carcinomas in FAP.

Thyroid carcinoma is the first symptom in some patients with familial adenomatous polyposis (FAP). We evaluated the cellular localization of beta-catenin in thyroid carcinomas associated (n = 4) or not associated (n = 173) with FAP, since loss of functional protein of the adenomatous polyposis coli (APC) gene leads to nuclear accumulation of beta-catenin in adenomas and carcinomas of the FAP colon. Immunoreactive beta-catenin was demonstrated at the cell membrane of glandular cells of the non-neoplastic thyroid and non-FAP carcinomas. On the other hand, cytoplasmic and nuclear accumulation of beta-catenin is specific to FAP-associated papillary carcinomas. The abnormality in the APC / beta-catenin pathway is thus also important in FAP-associated thyroid carcinoma, and beta-catenin immunohistochemistry is a feasible screening method to identify occult FAP in young patients with thyroid tumors.

Background and aims: The Korean Hereditary Tumor Registry has proposed criteria for suspected hereditary nonpolyposis colorectal cancer (S-HNPCC criteria I and II) and confirmed their validity in an international collaborative study. The S-HNPCC criteria included families that did not fulfill the Amsterdam criteria, but in whom HNPCC was nevertheless strongly suspected. The S-HNPCC criteria was also revised accordingly since some S-HNPCC families now fullfil the revised Amsterdam criteria. The original Amsterdam criteria have recently been revised, including some extracolonic cancers. This study compared the mutation detection rates between the revised and previous Amsterdam and S-HNPCC criteria. Patients and methods: Data on the mutational status of 393 HNPCC suspected families were collected from ten different institutes. Two hundred families were categorized into old S-HNPCC criteria (142 into criteria I and 58 into criteria II) and 193 families into Amsterdam criteria I. Results: Of the 142 old S-HNPCC criteria I families 24 fulfilled the Amsterdam criteria II as the data were reclassified according to the revised criteria, increasing the proportion of the families fulfilling the Amsterdam criteria by 12.4%. The mutation detection rate of the revised criteria was very little changed compared to the old criteria; 26% and 27% in the S-HNPCC criteria, and 50% and 52% in the Amsterdam criteria. Conclusion: The mutation detection rate is hardly affected by the revision of the Amsterdam criteria although the population of patients fulfilling the criteria is increased. The value of revised S-HNPCC criteria is equivalent to that of as the old S-HNPCC criteria in selecting of candidate patients for genetic testing.

PURPOSE: The aim of this study was to determine the frequency of mutations in the mismatch repair genes in families suspected of having hereditary nonpolyposis colorectal cancer. METHODS: We devised two criteria for families suspected of having hereditary nonpolyposis colorectal cancer (Criteria I and II). Criteria I consist of at least two first-degree relatives affected with colorectal cancer with at least one of the following: development of multiple colorectal tumors including adenomatous polyp, at least one colorectal cancer case diagnosed before the age of 50, and occurrence of a hereditary nonpolyposis colorectal cancer extracolonic cancer (endometrium, urinary tract, small intestine, stomach, hepatobiliary system, or ovary) in family members. Criteria II consist of one colorectal cancer patient with at least one of the following: early age of onset (

The level of mRNA for carcinoembryonic antigen (CEA) and nonspecific crossreacting antigen (NCA) in human colon adenocarcinomas and normal colon mucosa was analyzed by Northern blot hybridization using as probes 32P-labeled CEA cDNA and synthetic oligodeoxyribonucleotides specific to CEA and NCA mRNA sequences. The major 3.5-kb mRNA and a minor 4.2-kb mRNA are shown to be CEA-specific and expressed in both tissues, albeit at slightly different degrees, suggesting that the expression of CEA is regulated posttranscriptionally. Another minor mRNA of 2.9 kb is NCA-specific and expressed predominantly in cancerous tissues, suggesting its usefulness as a marker for colon cancer.