scholarly journals Diagnostic Application ofhMLH1Methylation in Hereditary Non-Polyposis Colorectal Cancer

2004 ◽  
Vol 20 (4-5) ◽  
pp. 277-282 ◽  
Author(s):  
Nagahide Matsubara

Colorectal cancer (CRC) due to mismatch repair (MMR) defect has distinct characteristics among unselected CRCs. These CRCs are biologically less aggressive and, thus, showing better prognosis but less sensitive to the 5FU-based chemotherapy. CRCs with MMR defect derive from both hereditary and sporadic reasons. Germline inactivation of MMR genes (hMLH1, hMSH2, hMSH6, andhPMS2) underlies the hereditary CRC with MMR defect (Lynch syndrome) and epigenetic silencing ofhMLH1gene causes the sporadic CRC with MMR defect. Hereditary and sporadic CRC with MMR defect can be detectable by microsatellite instability (MSI) test or immunohistochemical analysis among general CRCs. Lynch syndrome can be diagnosed by the clinical criteria or by genetic test to detect pathogenic germline mutations in MMR genes. However, both clinical criteria and genetic test are inadequate for the diagnosis of Lynch syndrome. Since genetic test for the diagnosis of the Lynch syndrome is expensive and not always identify pathogenic germline mutations, effective and inexpensive screening program is desirable. Here we propose a possible application of methylation test combined with MSI or pathological analysis as an effective and a cost-saving new strategy for screening of Lynch syndrome.

2019 ◽  
Vol 6 (4) ◽  
pp. 38-46
Author(s):  
A. V. Semyanikhina ◽  
N. I. Pospekhova ◽  
M. G. Filippova ◽  
D. A. Golovina ◽  
A. O. Rasulov ◽  
...  

Lynch syndrome is the most common cancer-prone syndrome associated with a high risk of colorectal cancer (CRC), neoplasms of the upper gastrointestinal system, the urinary tract, the female reproductive system, brain tumours and others. The only known form of hereditary endometrial cancer is also diagnosed as part of Lynch syndrome. One or more pathogenic germline mutations in one of the mismatch repair (MMR) genes are the cause of Lynch syndrome. Mapping of MMR genes and the discovery of microsatellite instability (MSI) have given rise to the possibility of using these clue characteristics of the pathogenic process for the elaboration of a screening test for Lynch syndrome. Being highly accurate and superior to all previously developed clinical criteria and guidelines, MSI-testing along with the assessment of the expression patterns of MMR proteins by immunohistochemistry has taken the leading role in the early diagnosis of Lynch syndrome. This article focuses on a brief review about the main evolutionary stages of clinical, anamnestic, molecular and genetic criteria for Lynch syndrome together with the results of our own research on the accuracy of the Amsterdam criteria, the Bethesda guidelines and MSI-diagnostics in the determination of the indications for MMR-genotyping in colorectal cancer patients suspected for Lynch syndrome.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abram Bunya Kamiza ◽  
Wen-Chang Wang ◽  
Jeng-Fu You ◽  
Reiping Tang ◽  
Huei-Tzu Chien ◽  
...  

AbstractPatients with Lynch syndrome have a high risk of colorectal cancer (CRC). In this study, we estimated the age- and sex-specific cumulative risks of CRC in Han Chinese patients with Lynch syndrome caused by the pathogenic germline mutations in MLH1 or MSH2 in Taiwan. Based on 321 mutation carriers and 419 non-mutation carriers from 75 pedigrees collected in an Amsterdam criteria family registry in Taiwan, the age- and sex-specific cumulative risks of CRC in male carriers of mutation in MLH1 and MSH2 at the age of 70 years were 60.3% (95% confidence interval (CI) = 31.1%–89.9%) and 76.7% (95% CI = 37.2%–99.0%), respectively. For females, the cumulative risks of CRC at the age of 70 were estimated to be 30.6% (95% CI = 14.3%–57.7%) and 49.3% (95% CI = 21.9%–84.5%) in the carriers of MLH1 and MSH2 germline mutations, respectively. In conclusion, the cumulative risks of CRC at the age of 70 in the Han Chinese patients is higher in mutation carriers than non-mutation carriers and male mutation carriers have a higher cumulative risk of developing CRC than the female mutation carriers.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 6600-6600 ◽  
Author(s):  
Lars Henrik Jensen ◽  
Anders Bojesen ◽  
Lene Byriel ◽  
Michael Hardt-Madsen ◽  
Katrine Urth Hansen ◽  
...  

6600 Background: A myriad of molecular markers has been proposed and tested with the promise of improving cancer care. Few have been validated and even fewer have been implemented in daily clinic. The most common hereditary colorectal cancer entity, Lynch Syndrome, can be identified in a subset of colorectal cancer patients by screening molecular markers for mismatch-repair (MMR) deficiency. We wanted to implement this screening in a Danish region, optimize quality, and describe the results. Methods: All colorectal cancer (CRC) patients diagnosed from October 2010 to September 2012 in the Region of Southern Denmark were included. Immunohistochemistry (IHC) was performed for protein expression of the MLH1, PMS2, MSH2, and MSH6 genes followed by MLH1 methylation analysis in cases with loss of pMLH1. Hereafter the indications for genetic counselling were lack of any MMR-protein – and in case missing pMLH1only those with no promoter-methylation of MLH1. Patients were included irrespectively of stage, post-mortem diagnosis, surgery, or other treatment. Accepted reasons for missed data were insufficient or autolyzed tumor material, but not data missing due to death, no surgery, or any logistic problem. Every 3-6 months the national pathology database was checked for missing data and feedback was given to the clinicians to ensure enrolling of all CRC patients. Results: CRC were diagnosed in 2,120 patients in a population of 1,200,000 with informative data for 1,932 patients at the time of analysis. 1,680 had normal protein expression of all four MMR-genes. 209 lacked pMLH1 of which 11 were not methylated. Loss of pMSH2, isolated pMSH6 or pPMS2 was seen in 23, 11, and 9 cases, respectively. Thus, the established screening program was positive in 54 patients. These patients are offered further genetic counselling and testing. Conclusions: Screening for Lynch Syndrome was feasible in a geographically defined area involving several clinical departments. Molecular screening for hereditary MMR-deficiency was positive in 54 of 1932 patients (2.8 %). Implementation of molecular markers in cancer care can be optimized by support from national databases and formalized quality feed back to the clinicians. Clinical trial information: NCT01216930.


2017 ◽  
Vol 43 (2) ◽  
pp. 134-141
Author(s):  
Utku Tantoğlu ◽  
Seher Yüksel ◽  
Cihangir Akyol ◽  
Haldun Doğan ◽  
Nükhet Kutlay ◽  
...  

Abstract Objectives: Our aim was to determine how well immunohistochemical analysis identified colon cancer patients with microsatellite instability in Turkish patients. Material and methods: Subjects were patients that underwent surgery for colorectal cancer in our institution between 2006 and 2011. Patients were grouped as: (1) suspected Lynch syndrome (n=14), (2) familial colorectal cancer (n=14), and (3) sporadic colorectal cancer groups (n=14). Mismatch repair proteins were analyzed by a four antibody-panel immunohistochemistry. Microsatellite instability analysis was conducted on DNA samples using MSI-PCR followed by fragment analysis. Results: The immunohistochemistry and PCR results had good concordance in 35/42 patients. Both microsatellite instability and at least one mismatch repair protein deficiency were detected in 11 patients, and both microsatellite stability and normal expression of mismatch repair proteins were detected in 24 patients. Test results were discordant in seven of the patients. Conclusion: As it is not feasible to perform expensive molecular tests in healthcare units in many developing countries, the four antibody-panel immunohistochemistry is a reliable and affordable method for screening for colorectal cancer, including Lynch syndrome and sporadic cases when suspected.


2014 ◽  
Vol 12 (5S) ◽  
pp. 829-831 ◽  
Author(s):  
Heather Hampel

NCCN has developed new guidelines for the assessment of high-risk familial/genetic colorectal cancer, and has positioned these recommendations within the guidelines for detection, prevention, and risk reduction. The Panel recommends that all patients with colorectal cancer be screened for Lynch syndrome, which occurs in 1 of every 35 patients and is the most common form of hereditary colorectal cancer. Such screening could be universal so that all tumors are genetically tested, or screening could be restricted to patients under the age of 70 and those aged 70 and older who meet clinical criteria.


2009 ◽  
Vol 45 (8) ◽  
pp. 1485-1493 ◽  
Author(s):  
Lucia Perez-Cabornero ◽  
Eladio Velasco ◽  
Mar Infante ◽  
David Sanz ◽  
Enrique Lastra ◽  
...  
Keyword(s):  
Rt Pcr ◽  

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 21067-21067
Author(s):  
D. Zakalik ◽  
N. S. Goldstein ◽  
W. L. Ducaine

21067 Background: Hereditary non-polyposis colorectal cancer (HNPCC) is a genetic disorder that results in an increased risk of early onset colorectal cancer (CRC). HNPCC is caused by germline mutations in DNA mismatch repair (MMR) genes, including MLH1 and MSH2, and is transmitted in an autosomal dominant manner. De novo germline mutations in MMR genes are exceedingly rare. We now describe a case of a de novo germline mutation in MLH1 associated with early onset CRC in a young woman with a negative family history. Methods: We present a case of a 31-year-old Caucasian female who presented with abdominal pain. Colonoscopy revealed a moderately differentiated adenocarcinoma with focal mucin production involving the sigmoid colon, with a final staging of T4N0M0. Genetic testing was offered because of her young age at diagnosis, having fulfilled the Bethesda guidelines. Microsatellite instability (MSI) testing using a panel of six microsatellite loci was performed on the tumor sample from the affected patient. Immunohistochemistry (IHC) testing for MLH1 and MSH2 was performed. Following counseling and with informed consent, DNA was isolated and sequenced using bi-directional PCR of the MLH1 gene. All exons of MLH1 and MSH2 were analyzed by standard Southern blot methods. Paternity was established using eight genetic loci. Results: The patient's tumor revealed high MSI and complete absence of MLH1 immunoreactivity. MSH2 IHC staining was normal. A large deletional mutation involving exons 5–12 of MLH1 was identified by Southern blot analysis. The patient's parents and siblings were tested and found to have wild type MLH1. Paternity was confirmed with greater than 99.9% certainty. Conclusions: De novo mutations in MMR genes are a rare cause of HNPCC. We report the first case of a large de novo deletion in the MLH1 gene accounting for early onset CRC. Such de novo mutations, albeit rare, must be considered in patients who present with early onset CRC and a negative family history. These results support the use of the Bethesda guidelines to identify individuals who may carry mutations in the MMR genes. No significant financial relationships to disclose.


2018 ◽  
Vol 36 (15_suppl) ◽  
pp. e13623-e13623 ◽  
Author(s):  
Nora Manoukian Forones ◽  
Fernanda Tereza Lima ◽  
Renan Paulo Martin ◽  
Leonardo Martins ◽  
Patricia Valera Lima Teixeira ◽  
...  

2012 ◽  
Author(s):  
Jose G. Guillem ◽  
John B Ammori

The majority of cases of inherited colorectal cancer (CRC) are accounted for by two syndromes: Lynch syndrome and familial adenomatous polyposis (FAP). In the management of FAP, the role of prophylactic surgery is clearly defined, although the optimal procedure for an individual patient depends on a number of factors. In the management of Lynch syndrome, the indications for prophylactic procedures are emerging. The authors address the clinical evaluation, investigation findings, medical and surgical therapy, and extracolonic diseases of FAP, attenuated form of FAP (AFAP), MYH-associated polyposis, Lynch syndrome, familial colorectal cancer type X (FCCTX), hyperplastic polyposis syndrome, Peutz-Jeghers syndrome, and juvenile polyposis syndrome. AFAP has been described that is associated with fewer adenomas and later development of CRC compared with classic FAP. The AFAP phenotype occurs in less than 10% of FAP patients. The clinical criteria for AFAP are no family members with more than 100 adenomas before the age of 30 years and (1) at least two patients with 10 to 99 adenomas at age over 30 years or (2) one patient with 10 to 99 adenomas at age over 30 years and a first-degree relative with CRC with few adenomas. Given that polyposis has a later onset and the risk of CRC is less well established in AFAP, some authors question whether prophylactic colectomy is necessary in all AFAP patients.


Sign in / Sign up

Export Citation Format

Share Document