TY  - JOUR
AU  - Helderman, Noah C
AU  - Andini, Katarina D
AU  - van Leerdam, Monique E
AU  - van Hest, Liselotte P
AU  - Hoekman, Daniël R
AU  - Ahadova, Aysel
AU  - Bajwa-Ten Broeke, Sanne W
AU  - Bosse, Tjalling
AU  - van der Logt, Elise M J
AU  - Imhann, Floris
AU  - Kloor, Matthias
AU  - Langers, Alexandra M J
AU  - Smit, Vincent T H B M
AU  - Terlouw, Diantha
AU  - van Wezel, Tom
AU  - Morreau, Hans
AU  - Nielsen, Maartje
TI  - MLH1 promotor hypermethylation in colorectal and endometrial carcinomas from patients with Lynch syndrome.
JO  - The journal of molecular diagnostics
VL  - 26
IS  - 2
SN  - 1525-1578
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - DKFZ-2023-02578
SP  - 106-114
PY  - 2024
N1  - 2024 Feb;26(2):106-114
AB  - Screening for Lynch syndrome (LS) in colorectal cancer (CRC) and endometrial cancer (EC) patients generally involves immunohistochemical staining of the mismatch repair (MMR) proteins. In case of MLH1 protein loss, MLH1 promotor hypermethylation (MLH1-PM) testing is performed to indirectly distinguish constitutional MLH1 variants from somatic epimutations. However, in recent years a growing number of studies have reported that MLH1-PM and pathogenic constitutional MMR variants are not mutually exclusive. This study describes six new and 86 previously reported MLH1-PM CRCs or ECs in LS patients. Of these, methylation of the MLH1 gene promotor 'C region' was reported in 30 MLH1, six MSH2, six MSH6 and three PMS2 variant carriers at median ages at diagnosis of 48.5 (IQR 39-56.75), 39 (IQR 29-51), 58 (IQR 53.5-67) and 68 (IQR 65.6-68.5) years, respectively. For 31 MLH1-PM CRCs in LS patients from literature, only the 'B region' of the MLH1 gene promotor was tested, whereas for 13 literature cases the tested MLH1 gene promotor region was not specified. Collectively, these data indicate that a diagnosis of LS should not be excluded when MLH1-PM is detected. Clinicians should carefully consider whether or not follow-up genetic MMR gene testing should be offered, with age < 60-70 years and/or a positive family history amongst other factors being suggestive for a potential constitutional MMR gene defect.
KW  - Lynch syndrome (Other)
KW  - MLH1 promotor hypermethylation (Other)
KW  - colorectal cancer (Other)
KW  - endometrial cancer (Other)
KW  - genetic testing (Other)
KW  - immunohistochemistry (Other)
KW  - mismatch repair (Other)
KW  - screening (Other)
LB  - PUB:(DE-HGF)16
C6  - pmid:38061582
DO  - DOI:10.1016/j.jmoldx.2023.10.005
UR  - https://inrepo02.dkfz.de/record/285997
ER  -