National Cancer Institute®
Last Modified: October 1, 2002
1
UI - 12269688
AU - Baxter NP; Duffy SR; Sheridan E
TI -
Endometrial abnormalities in three sisters from a family with hereditary
non-polyposis colorectal cancer syndrome.
SO - BJOG 2002 Sep;109(9):1076-8
AD - University Department of Obstetrics and Gynaecology, St James's
University Hospital, Leeds, UK.
2
UI - 12353948
AU - Calvert PM; Frucht H
TI -
The genetics of colorectal cancer.
SO - Ann Intern Med 2002 Oct 1;137(7):603-12
AD - Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA.
Colon cancer is a common disease that can be sporadic, familial, or
inherited. Recent advances have contributed to the understanding of the
molecular basis of these various patterns of colon cancer. Germline
genetic mutations are the basis of inherited colon cancer syndromes; an
accumulation of somatic mutations in a cell is the basis of sporadic
colon cancer; and, in Ashkenazi Jewish persons, a mutation that was
previously thought to be a polymorphism may cause familial colon cancer.
Mutations of three different classes of genes have been described in
colon cancer etiology: oncogenes, suppressor genes, and mismatch repair
genes. Knowledge of many of the specific mutations responsible for colon
carcinogenesis allows an understanding of the phenotypic manifestations
observed and forms the basis of genetic testing for inherited disease.
Although genetic testing is possible and available, it is only an
adjunct to the clinical management of persons at risk for colon cancer
and patients with colon cancer. As a result of advances in the
understanding of the molecular causes of colon cancer and the
availability of colon cancer screening methods such as colonoscopy, it
should be possible to prevent the vast majority of colon cancer in our
society. Practicing clinicians should recognize the patterns of clinical
colon cancer, understand its causes, and be able to use genetic testing
and endoscopic screening for prevention.
3
UI - 12353974
AU - Anonymous
TI -
Summaries for patients. The genetics of colorectal cancer.
SO - Ann Intern Med 2002 Oct 1;137(7):I48
4
UI - 12019211
AU - Kariola R; Raevaara TE; Lonnqvist KE; Nystrom-Lahti M
TI -
Functional analysis of MSH6 mutations linked to kindreds with putative
hereditary non-polyposis colorectal cancer syndrome.
SO - Hum Mol Genet 2002 May 15;11(11):1303-10
AD - Department of Biosciences, Division of Genetics, University of Helsinki,
FIN-00014 Helsinki, Finland.
To date, five mismatch-repair (MMR) genes, MLH1, MSH2, MSH6, MSH3 and
PMS2, are known to be involved in human MMR function. Two of those, MLH1
and MSH2, are further the most common susceptibility genes for
hereditary non-polyposis colorectal cancer (HNPCC), while MSH3 and PMS2
are seldom (PMS2) or not at all (MSH3 ) reported to be involved in
HNPCC. Despite the increasing number of MSH6 germline mutations, their
pathogenicity remains questionable, because the mutations are mainly
linked to putative HNPCC families lacking the typical clinical and
molecular characteristics of the syndrome, such as early age at onset
and high microsatellite instability (MSI). High MSI is a consequence of
MMR defect, and the pathogenicity of germline mutations in HNPCC is thus
linked to malfunction of MMR. To address the question of whether and how
MSH6 mutations cause susceptibility to HNPCC, we studied
heterodimerization of four MSH6 variants with MSH2, and the
functionality of these MutSalpha complexes in an in vitro MMR assay. All
mutations occurred in putative HNPCC patients. Irrespective of the type
or the site of the amino acid substitutions, all the variants repaired
G.T mismatches to A.T as wild-type MSH6 protein. However, the MSH6
protein carrying a mutation in the MSH2/MSH6 interaction region was
poorly expressed, suggesting problems in its stability. Our results are
clinically relevant, since they demonstrate that under the stable in
vitro conditions, when the amounts of the proteins are adequate for
repair, the tested MSH6 mutations do not affect repair function.
Consequently, while the typical HNPCC syndrome is associated with
problems in repair reaction, the pathogenicity of mutations in putative
HNPCC families may be linked to other biochemical events.
5
UI - 12362848
AU - Nilbert M; Gronberg H; Lindblom A
TI -
[Essential to discover hereditary colorectal and endometrial cancer.
Mutations in "HNPCC individuals" can cause several different tumors]
SO - Lakartidningen 2002 Aug 22;99(34):3296-300
AD - Onkologiska kliniken, Universitetssjukhuset i Lund.
Mef.Nilbert@onk.lu.se
Hereditary Nonpolyposis Colorectal Cancer (HNPCC) is one of our most
common hereditary cancer syndromes and confers an increased risk for
several tumor types, with the greatest lifetime risks being for
colorectal cancer and endometrial cancer. Hereditary mutations in one of
several mismatch-repair (MMR) genes cause the syndrome, and 39 such
mutations, involving the genes MLH1, MSH2 and MSH6, have been been
characterized in Sweden. Screening programs for HNPCC have been shown to
be cost-effective and to prevent cancer. Identification of HNPCC
individuals thus allows prevention of additional tumors in the patient
as well as in the family.
6
UI - 12352241
AU - Green J; O'Driscoll M; Barnes A; Maher ER; Bridge P; Shields K; Parfrey
TI -
PS
Impact of gender and parent of origin on the phenotypic expression of
hereditary nonpolyposis colorectal cancer in a large Newfoundland
kindred with a common MSH2 mutation.
SO - Dis Colon Rectum 2002 Sep;45(9):1223-32
AD - Medical Genetics Program, Memorial University, St. John's, Newfoundland,
Canada.
PURPOSE: This study was designed to provide precise estimates of death
and cancer risks, by gender and parent of origin, in hereditary
nonpolyposis colorectal cancer independent of mutation, geographic
variation, and ascertainment bias. METHODS: A group of 12 families with
a founder MSH2 mutation (nucleotide 943+3, A --> T) causing hereditary
nonpolyposis colorectal cancer was identified in Newfoundland. Genetic
testing was offered to those at 50 percent risk of inheriting the
mutation. Medical records were reviewed to identify cancer types, age at
onset of cancer, and age at death. Ascertainment bias was limited by
analyzing only sibships with good ascertainment of genetic status (> or
=50 percent of sibships had known genetic status). RESULTS: Of 302
family members with hereditary nonpolyposis colorectal cancer or at 50
percent risk, 151 (50 percent) were considered to be mutation carriers,
96 (32 percent) were mutation negative, and 55 (18 percent) were of
unknown mutation status. By age 50 years, 72 percent of males and 72
percent of females who were hereditary nonpolyposis colorectal cancer
mutation carriers had developed cancer. The age-related risks of
colorectal cancer or of death of cancer were significantly higher in
males than in females (relative risk = 2.8, P = 0.0001 and relative risk
= 2.1, P = 0.01, respectively). The mutation was transmitted by the
mother more frequently than the father. Females who inherited the
mutation from their father had an increased risk of developing
colorectal cancer (relative risk = 2.5, P = 0.05) and of dying of cancer
(relative risk = 2.7, P = 0.04) compared with females who inherited the
mutation from their mother. CONCLUSIONS: Investigation of large kindreds
from the same geographic area who share the same MSH2 mutation and in
whom family members have been identified with little ascertainment bias
suggests that the risks for colorectal cancer and death of cancer are
higher for male mutation carriers than for females and that females who
inherit the mutation from their father are at higher risk of colorectal
cancer than females who inherit the mutation from their mother.
7
UI - 10656143
AU - Janin N
TI -
[Explanation of enigmas of the Lynch syndrome thanks to a new
carcinogenesis model characterized by an unorthodox initiation process]
SO - C R Acad Sci III 1999 Dec;322(12):1017-31
AD - Unite d'oncologie medicale, Hopital Laennec, Paris, France.
The genotype-phenotype relationship of Lynch syndrome displays many
enigmatic features which cannot be explained satisfactorily by the
prevailing concepts of carcinogenesis and genetic predisposition to
cancer. We propose here a new model of carcinogenesis divided into two
and only two evolutive phases: a) a preliminary phase starting with the
counter-selective loss of mismatch repair function, in which most clones
with the RER mutator phenotype are eliminated through apoptosis or an
accelerated ageing process; b) an explosive phase that is initiated only
if mutations blocking apoptosis and senescence, rapidly acquired during
the short life span of the non-transformed RER+ clones, eventually
rescue one mismatch repair-deficient cell that gives rise to the
malignant clone. Carcinogenesis is proposed here to progress
irreversibly and very rapidly once initiated. We shall show how this
model provides a meaningful etiologic and pathogenic interpretation of
all the curious features of Lynch syndrome.
8
UI - 11969232
AU - Tejpar S; Van Cutsem E
TI -
Molecular and genetic defects in colorectal tumorigenesis.
SO - Best Pract Res Clin Gastroenterol 2002 Apr;16(2):171-85
AD - Center for Human Genetics, University Hospital Gasthuisberg, Leuven,
Belgium.
Colorectal cancers, whether sporadic or hereditary, are caused by a
defined set of molecular events. There are at least two different
pathogenetic pathways for colorectal cancer: the chromosomal instability
pathway and the microsatellite instability pathway; the two major
inherited syndromes, familial adenomatous polyposis (FAP) and hereditary
non-polyposis colorectal cancer (HNPCC), are examples of these two
mechanisms. These different pathways, however, converge on common
pathological entities that have crucial functions in the regulation of
normal crypt homeostasis. Preventive strategies aimed at reversing these
changes, or therapeutic interventions targeting cell populations with
these alterations, should be most efficacious. Genetic testing for
inherited syndromes is now available and allows appropriate management
of these disorders. Further insight into colorectal tumorigenesis
pathways can lead to the development of useful prognostic indicators and
target preventive and therapeutic strategies in the management of
colorectal cancer. Copyright 2002 Elsevier Science Ltd.
The above citations and abstracts reflect those newly added to CANCERLIT for the month and topic listed in the title. The citations have been retrieved from CANCERLIT using a predefined search strategy of indexed subject terms. Although the search strategy has been refined as best as possible, citations may appear that are not directly related to the topic, and occasionally relevant references may be omitted.