| 1. |
- Ericson, K, et al.
(författare)
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Defective mismatch-repair in patients with multiple primary tumours including colorectal cancer
- 2003
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Ingår i: European Journal of Cancer. - 1879-0852. ; 39:2, s. 8-240
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Tidskriftsartikel (refereegranskat)abstract
- Individuals with an inherited predisposition to cancer development are at an increased risk of developing multiple tumours. Hereditary non-polyposis colorectal cancer (HNPCC) is one of the most common hereditary cancer syndromes and is estimated to account for approximately 2% of colorectal cancers. However, HNPCC individuals are at an increased risk of developing other tumour types such as cancers of the endometrium, urothelium and small intestine. We have utilised a population-based regional cancer registry to identify all patients with double primary colorectal cancers and at least one additional malignancy and characterised the tumour spectrum in this patient group. We subsequently selected those 47 individuals who had developed at least four malignancies, including two colorectal cancers, for studies of the tumour characteristics associated with HNPCC. In total, these individuals developed 209 tumours, 156 of which were successfully retrieved. Microsatellite instability (MSI), a phenomenon caused by defective mismatch-repair (MMR), was identified in 63/154 (41%) evaluable tumours with a MSI-high pattern in 59 and a MSI-low pattern in four tumours. All tumours were immunohistochemically stained for the MMR proteins MLH1 and MSH2, with loss of expression in 55/63 (87%) MSI tumours and in 2/89 (2%) microsatellite stable (MSS) tumours. This loss affected MLH1 in 24 tumours and MSH2 in 33 tumours. A concordant loss of expression for the same MMR protein in several tumours from the same individual, a pattern that strongly suggests an underlying germline MMR gene mutation, was found in 17/45 (38%) patients and affected MLH1 in 8 patients and MSH2 in 9 patients. We conclude that the development of multiple primary tumours, including synchronous or metachronous colorectal cancers, is associated with an increased frequency of MSI and loss of immunohistochemical expression of MLH1 and MSH2.
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| 2. |
- Planck, M, et al.
(författare)
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Somatic frameshift alterations in mononucleotide repeat-containing genes in different tumor types from an HNPCC family with germline MSH2 mutation
- 2000
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Ingår i: Genes, Chromosomes and Cancer. - 1045-2257. ; 29:1, s. 33-39
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Tidskriftsartikel (refereegranskat)abstract
- Hereditary nonpolyposis colorectal cancer (HNPCC) is caused by a germline mutation in one of several DNA repair genes, which in the tumors is reflected as microsatellite instability (MSI). MSI+ tumors have been found to carry somatic frameshift mutations in mononucleotide repeats within the coding regions of several genes involved in growth control, apoptosis, and DNA repair, e.g., TGFBRII, BAX, IGFIIR, TCF4, MSH3, and MSH6. We have studied the occurrence of somatic frameshift alterations in these mononucleotide repeat-containing genes in 24 tumors (15 colorectal cancers, 1 colon adenoma, 4 endometrial cancers, 1 ovarian cancer, 1 gastric cancer, 1 urothelial cancer, and 1 duodenal cancer) from 14 individuals in an HNPCC family with germline hMSH2 mutation. Such somatic frameshift mutations occurred at a variable frequency; the long mononucleotide repeats that characterize intronic MSI markers were mutated in the majority of tumors, 13 of the tumors displayed alterations in the (A)(10) tract of TGFBII, eight tumors (all of gastrointestinal origin) had alterations in the (A)(9) repeat of TCF4, and one to five tumors had somatic frameshift alterations in the shorter mononucleotide repeats of IGFIIR, BAX, MSH3, and MSH6. Thus, longer mononucleotide repeats were more frequently affected by somatic frameshift mutations. The pattern of alterations varied between the tumors from different family members as well as between different tumors from the same individual. To what extent this variable pattern depends on the widespread mismatch repair deficiency induced by the underlying MSH2 mutation, or represents alternative ways whereby the tumors can achieve a tumorigenic phenotype, is unknown. We suggest, however, that the accumulation of somatic frameshifts, rather than the specific loci in which these occur, drives the development of the tumorigenic phenotype in HNPCC.
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| 3. |
- Planck, M, et al.
(författare)
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Increased cancer risk in offspring of women with colorectal carcinoma : a Swedish register-based cohort study
- 2000
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Ingår i: Cancer. - 0008-543X. ; 89:4, s. 9-741
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Colorectal carcinoma is one of the most common malignancies in the Western population, and a considerable proportion of colorectal carcinomas are estimated to have a familial background.METHODS: Individuals whose mothers were diagnosed with colon carcinoma or rectal carcinoma from 1958 to 1993, a total of 1. 48 million person-years, constituted the cohort of this Swedish population-based register study. The children were born during the period 1941-1993, and the cancer incidence was observed during the period 1961-1993, with the expected national Swedish incidence used as a reference.RESULTS: A significantly increased risk of colon carcinoma, rectal carcinoma, and non-Hodgkin lymphoma was observed in the cohort. The cancer risk was more pronounced in children whose mothers were age < 50 years at the time of diagnosis or had developed metachronous colorectal carcinoma. Whereas colon carcinoma in the proband implied an increased risk for both colon tumors and rectal tumors, the offspring of women who were diagnosed with rectal carcinoma were at increased risk of developing rectal carcinoma, but no significantly altered risk of colon carcinoma was observed. In the cohort, the cumulative risk for colorectal carcinoma before age 50 years was increased about 3.0 times compared with the general population.CONCLUSIONS: This report shows a significant familial aggregation of colorectal carcinoma, demonstrates possible differences in hereditary pattern between colon carcinoma and rectal carcinoma, and confirms that younger age at the time of diagnosis or the occurrence of metachronous tumors indicate familial carcinoma.
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