Molecular biology from bench-to-bedside - which colorectal cancer patients should be referred for genetic counselling and risk assessment

Lars Henrik Jensen, Lars Dysager, Jan Lindebjerg, Steen Kølvrå, Lene Byriel, Dorthe Gylling Crüger

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

Lynch syndrome is associated with deficiency of the mismatch repair genes MLH1, MSH2, MSH6 or PMS2. However, most MLH1 deficient tumours are sporadic in origin, and they can be identified if harbouring a BRAF V600E mutation or hypermethylation of the MLH1 gene promoter. The aim of this study was to validate our previously suggested clinically applicable strategy based on molecular characteristics for identifying which patients to refer for genetic counselling. The strategy was validated in an unselected cohort of 287 colorectal cancer patients. All tumours were tested for MLH1, PMS2, MSH2 and MSH6 protein expression with immunohistochemistry. DNA from MLH1 negative tumours was sequenced for BRAF mutations. If BRAF was wild-type, MLH1 promoter was subsequently analyzed for promoter hypermethylation. Most tumours, 251 (88%), stained positive for all four proteins. Six (2%) had negative MSH2 and one (<1%) isolated loss of MSH6. MLH1 and PMS2 were negative in 29 cases (10%). DNA quality allowed BRAF analysis in 27 of these with 14 mutations and 13 wild-type. DNA quality allowed methylation analysis in 11 of the 13 BRAF wild-type, and all but one were methylated. Subsequently, Lynch syndrome could not be ruled out in 12 patients. A follow-up at 8-10 years revealed four definite cases of Lynch syndrome and three highly suspicious. An easy and clinically applicable step-wise approach with immunohistochemistry (100%), BRAF sequencing (10%) and methylation analysis (5%) identified several patients with hereditary cancer. It is feasible to perform a molecular screening to select patients for genetic counselling.

OriginalsprogEngelsk
TidsskriftEuropean journal of cancer (Oxford, England : 1990)
Vol/bind46
Udgave nummer10
Sider (fra-til)1823-8
Antal sider6
ISSN0959-8049
DOI
StatusUdgivet - jul. 2010

Fingeraftryk

Genetic Counseling
Colorectal Neoplasms
Neoplasms
Mutation
DNA
Proteins

Citer dette

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title = "Molecular biology from bench-to-bedside - which colorectal cancer patients should be referred for genetic counselling and risk assessment",
abstract = "Lynch syndrome is associated with deficiency of the mismatch repair genes MLH1, MSH2, MSH6 or PMS2. However, most MLH1 deficient tumours are sporadic in origin, and they can be identified if harbouring a BRAF V600E mutation or hypermethylation of the MLH1 gene promoter. The aim of this study was to validate our previously suggested clinically applicable strategy based on molecular characteristics for identifying which patients to refer for genetic counselling. The strategy was validated in an unselected cohort of 287 colorectal cancer patients. All tumours were tested for MLH1, PMS2, MSH2 and MSH6 protein expression with immunohistochemistry. DNA from MLH1 negative tumours was sequenced for BRAF mutations. If BRAF was wild-type, MLH1 promoter was subsequently analyzed for promoter hypermethylation. Most tumours, 251 (88{\%}), stained positive for all four proteins. Six (2{\%}) had negative MSH2 and one (<1{\%}) isolated loss of MSH6. MLH1 and PMS2 were negative in 29 cases (10{\%}). DNA quality allowed BRAF analysis in 27 of these with 14 mutations and 13 wild-type. DNA quality allowed methylation analysis in 11 of the 13 BRAF wild-type, and all but one were methylated. Subsequently, Lynch syndrome could not be ruled out in 12 patients. A follow-up at 8-10 years revealed four definite cases of Lynch syndrome and three highly suspicious. An easy and clinically applicable step-wise approach with immunohistochemistry (100{\%}), BRAF sequencing (10{\%}) and methylation analysis (5{\%}) identified several patients with hereditary cancer. It is feasible to perform a molecular screening to select patients for genetic counselling.",
keywords = "Adenocarcinoma, Adult, Aged, Aged, 80 and over, Colorectal Neoplasms, Colorectal Neoplasms, Hereditary Nonpolyposis, DNA Methylation, DNA Mismatch Repair, Female, Genetic Counseling, Humans, Male, Microsatellite Instability, Middle Aged, Patient Selection, Promoter Regions, Genetic, Proto-Oncogene Proteins B-raf, Referral and Consultation, Risk Assessment",
author = "Jensen, {Lars Henrik} and Lars Dysager and Jan Lindebjerg and Steen K{\o}lvr{\aa} and Lene Byriel and Cr{\"u}ger, {Dorthe Gylling}",
note = "Copyright 2010 Elsevier Ltd. All rights reserved.",
year = "2010",
month = "7",
doi = "10.1016/j.ejca.2010.03.016",
language = "English",
volume = "46",
pages = "1823--8",
journal = "European Journal of Cancer",
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Molecular biology from bench-to-bedside - which colorectal cancer patients should be referred for genetic counselling and risk assessment. / Jensen, Lars Henrik; Dysager, Lars; Lindebjerg, Jan; Kølvrå, Steen; Byriel, Lene; Crüger, Dorthe Gylling.

I: European journal of cancer (Oxford, England : 1990), Bind 46, Nr. 10, 07.2010, s. 1823-8.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Molecular biology from bench-to-bedside - which colorectal cancer patients should be referred for genetic counselling and risk assessment

AU - Jensen, Lars Henrik

AU - Dysager, Lars

AU - Lindebjerg, Jan

AU - Kølvrå, Steen

AU - Byriel, Lene

AU - Crüger, Dorthe Gylling

N1 - Copyright 2010 Elsevier Ltd. All rights reserved.

PY - 2010/7

Y1 - 2010/7

N2 - Lynch syndrome is associated with deficiency of the mismatch repair genes MLH1, MSH2, MSH6 or PMS2. However, most MLH1 deficient tumours are sporadic in origin, and they can be identified if harbouring a BRAF V600E mutation or hypermethylation of the MLH1 gene promoter. The aim of this study was to validate our previously suggested clinically applicable strategy based on molecular characteristics for identifying which patients to refer for genetic counselling. The strategy was validated in an unselected cohort of 287 colorectal cancer patients. All tumours were tested for MLH1, PMS2, MSH2 and MSH6 protein expression with immunohistochemistry. DNA from MLH1 negative tumours was sequenced for BRAF mutations. If BRAF was wild-type, MLH1 promoter was subsequently analyzed for promoter hypermethylation. Most tumours, 251 (88%), stained positive for all four proteins. Six (2%) had negative MSH2 and one (<1%) isolated loss of MSH6. MLH1 and PMS2 were negative in 29 cases (10%). DNA quality allowed BRAF analysis in 27 of these with 14 mutations and 13 wild-type. DNA quality allowed methylation analysis in 11 of the 13 BRAF wild-type, and all but one were methylated. Subsequently, Lynch syndrome could not be ruled out in 12 patients. A follow-up at 8-10 years revealed four definite cases of Lynch syndrome and three highly suspicious. An easy and clinically applicable step-wise approach with immunohistochemistry (100%), BRAF sequencing (10%) and methylation analysis (5%) identified several patients with hereditary cancer. It is feasible to perform a molecular screening to select patients for genetic counselling.

AB - Lynch syndrome is associated with deficiency of the mismatch repair genes MLH1, MSH2, MSH6 or PMS2. However, most MLH1 deficient tumours are sporadic in origin, and they can be identified if harbouring a BRAF V600E mutation or hypermethylation of the MLH1 gene promoter. The aim of this study was to validate our previously suggested clinically applicable strategy based on molecular characteristics for identifying which patients to refer for genetic counselling. The strategy was validated in an unselected cohort of 287 colorectal cancer patients. All tumours were tested for MLH1, PMS2, MSH2 and MSH6 protein expression with immunohistochemistry. DNA from MLH1 negative tumours was sequenced for BRAF mutations. If BRAF was wild-type, MLH1 promoter was subsequently analyzed for promoter hypermethylation. Most tumours, 251 (88%), stained positive for all four proteins. Six (2%) had negative MSH2 and one (<1%) isolated loss of MSH6. MLH1 and PMS2 were negative in 29 cases (10%). DNA quality allowed BRAF analysis in 27 of these with 14 mutations and 13 wild-type. DNA quality allowed methylation analysis in 11 of the 13 BRAF wild-type, and all but one were methylated. Subsequently, Lynch syndrome could not be ruled out in 12 patients. A follow-up at 8-10 years revealed four definite cases of Lynch syndrome and three highly suspicious. An easy and clinically applicable step-wise approach with immunohistochemistry (100%), BRAF sequencing (10%) and methylation analysis (5%) identified several patients with hereditary cancer. It is feasible to perform a molecular screening to select patients for genetic counselling.

KW - Adenocarcinoma

KW - Adult

KW - Aged

KW - Aged, 80 and over

KW - Colorectal Neoplasms

KW - Colorectal Neoplasms, Hereditary Nonpolyposis

KW - DNA Methylation

KW - DNA Mismatch Repair

KW - Female

KW - Genetic Counseling

KW - Humans

KW - Male

KW - Microsatellite Instability

KW - Middle Aged

KW - Patient Selection

KW - Promoter Regions, Genetic

KW - Proto-Oncogene Proteins B-raf

KW - Referral and Consultation

KW - Risk Assessment

U2 - 10.1016/j.ejca.2010.03.016

DO - 10.1016/j.ejca.2010.03.016

M3 - Journal article

C2 - 20417091

VL - 46

SP - 1823

EP - 1828

JO - European Journal of Cancer

JF - European Journal of Cancer

SN - 0959-8049

IS - 10

ER -