scholarly journals Detection of Mismatch Repair and Microsatellite Instability in Colorectal Cancer Patients

2020 ◽  
Vol 18 (2) ◽  
Author(s):  
Muhammad Ishaque Faizee

Introduction:  Colorectal cancer is the third most common cancer worldwide. Microsatellite instability (MSI) contributes to be one of the main mechanisms in colorectal cancer. Individuals with MSI tumors have loss of expression of one or more Mismatch Repair proteins. MSI tumors have better survival rate than microsatellite stable (MSS) tumors, poor response to 5FU-based adjuvant chemotherapy and relatively successful immunotherapy in metastatic MSI tumors. Immunohistochemistry recognizes altered gene by recognizing loss of its protein product. Based on the presence or absence of Mismatch repair proteins, groups are classified into Mismatch repair proficient (MMR-p) and Mismatch repair deficient (MMR-d).  Aim:  To investigate the immunohistochemical profile of Mismatch repair proteins namely: hMLH1, hMSH2, hMSH6, and hPMS2 in surgically resected colorectal cancer specimens.  Materials and Method:  A total of 76 cases were selected from the Histopathology Department of HTAA to determine MMR protein expression status. Cases were either MMR-p or MMR-d. Results:  Of the specimens which were properly immunostained, seventeen out of seventy-six cases (22.37%) showed loss of one or more MMR proteins expression and thus were MMR-d. MLH1, MSH2, MSH6 and PMS2 protein expression was detected as 85.53% (65/76), 81.6% (62/76), 88.16% (67/76), and 76.32% (58/76), respectively. Conclusion: Mismatch repair proteins profile should be done using immunohistochemistry in  local laboratories on these selected cases before referring for the expensive molecular test.

2017 ◽  
Vol 5 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Nour El Hoda S. Ismael ◽  
Samar A. El Sheikh ◽  
Suzan M. Talaat ◽  
Eman M. Salem

BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers worldwide. Microsatellite instability (MSI) is detected in about 15% of all colorectal cancers. CRC with MSI has particular characteristics such as improved survival rates and better prognosis. They also have a distinct sensitivity to the action of chemotherapy.AIM: The aim of the study was to detect microsatellite instability in a cohort of colorectal cancer Egyptian patients using the immunohistochemical expression of mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2).MATERIAL AND METHODS: Cases were divided into Microsatellite stable (MSS), Microsatellite unstable low (MSI-L) and Microsatellite unstable high (MSI-H). This Microsatellite stability status was correlated with different clinicopathological parameters.RESULTS: There was a statistically significant correlation between the age of cases, tumor site & grade and the microsatellite stability status. There was no statistically significant correlation between the gender of patients, tumor subtype, stage, mucoid change, necrosis, tumor borders, lymphocytic response, lymphovascular emboli and the microsatellite stability status.CONCLUSION: Testing for MSI should be done for all colorectal cancer patients, especially those younger than 50 years old, right sided and high-grade CRCs.


ESMO Open ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 100120
Author(s):  
A. Guyot D'Asnières De Salins ◽  
G. Tachon ◽  
R. Cohen ◽  
L. Karayan-Tapon ◽  
A. Junca ◽  
...  

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.


2011 ◽  
Vol 135 (12) ◽  
pp. 1539-1544 ◽  
Author(s):  
Thomas Arnason ◽  
Heidi L Sapp ◽  
Daniel Rayson ◽  
Penelope J Barnes ◽  
Magdalena Drewniak ◽  
...  

Context.—Two recent studies have identified a high rate of microsatellite instability (MSI) in pancreatic neuroendocrine tumors (pNETs). Microsatellite instability is rare in small intestinal neuroendocrine tumors (NETs). It is unclear why there is discordance in the frequency of MSI in the 2 studies of pNETs and why this mechanism is comparatively rare in small intestinal tumors. Loss of expression of DNA mismatch repair (MMR) proteins, which is known to correlate strongly with MSI, is not well studied in pancreatic or small intestinal NETs. Objective.—To determine if there is loss of expression of MMR protein expression in pancreatic or small intestinal NETs. Design.—Sixty-nine patients (31 male, 38 female; mean age, 59.2 years) were identified who had a resection for a primary pancreatic (n  =  35) or primary small intestinal (n  =  34) NET during an 18-year period. Immunohistochemical stains for MLH1, MSH2, MSH6, and PMS2 were applied to archived tissue from all cases. All pNETs with adequate tissue (n  =  32) were also assessed by MSI analysis. Results.—There was preserved expression of MLH1, MSH2, MSH6, and PMS2 in all 35 pNETs. Of 32 pNETs tested by polymerase chain reaction, 28 were microsatellite stable and DNA did not amplify in 4. In 34 small intestinal NETs, 2 cases had indeterminate MLH1 and 1 case had indeterminate PMS2 expression. The remainder had intact MMR protein expression. Conclusion.—Defects in DNA MMR proteins are rare in pancreatic and small intestinal NETs, raising doubt that MSI plays a significant role in the pathogenesis of these tumors.


2017 ◽  
Vol 142 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Esmeralda Celia Marginean ◽  
Barbara Melosky

Context.— Colorectal cancer (CRC) represents the third most-common cancer in developed countries and is a leading cause of cancer deaths worldwide. Two recognized pathways contribute to CRC development: a more-common chromosomal instability pathway and, in 15% of cases, a deficient mismatch repair or microsatellite instability–high (MSI-H) pathway. The MSI-H CRC can be associated with somatic or germline mutations. Microsatellite status has been recognized as a prognostic and predictive biomarker. Objectives.— To summarize the molecular pathways of CRC, with an emphasis on the MSI (mismatch repair) pathway; the recommended MSI testing algorithms and interpretation; and the prognostic and predictive role of MSI-H status in personalized treatment, including adjuvant chemotherapy, targeted therapy, and immune checkpoint inhibitor therapy. Data Sources.— A PubMed (US National Library of Medicine, Bethesda, Maryland) review was performed for articles pertaining to CRC, MSI and mismatch repair systems, molecular classification, immune response, programmed death receptor-1/programmed death ligand-1, and immunotherapy. Conclusions.— Although the TNM classification of malignant tumor stage remains the key determinant of CRC prognosis and treatment, there are considerable stage-independent, interindividual differences in clinical outcome and therapy response by patients. In addition, MSI-H status has an important role in CRC management and can be reliably detected by molecular and immunohistochemistry techniques and genetic testing. Efforts must be made to identify whether MSI-H CRC is germline or sporadic to ensure appropriate treatment, accurate prognosis, and risk assessment for relatives. Microsatellite status has been recognized as a good prognostic indicator and is predictive of a poor response to 5-fluorouracil–based chemotherapy and a good response to programmed death ligand-1 inhibitor pembrolizumab in metastatic/refractory MSI-H CRC.


2005 ◽  
Vol 23 (27) ◽  
pp. 6524-6532 ◽  
Author(s):  
Melissa C. Southey ◽  
Mark A. Jenkins ◽  
Leeanne Mead ◽  
Jonathan Whitty ◽  
Melanie Trivett ◽  
...  

Purpose The relationships between mismatch repair (MMR) protein expression, microsatellite instability (MSI), family history, and germline MMR gene mutation status have not been studied on a population basis. Methods We studied 131 unselected patients with colorectal cancer diagnosed younger than age 45 years. For the 105 available tumors, MLH1, MSH2, MSH6, and PMS2 protein expression using immunohistochemistry (IHC) and MSI were measured. Germline DNA was screened for hMLH1, hMSH2, hMSH6, and hPMS2 mutations for the following patients: all from families fulfilling the Amsterdam Criteria for hereditary nonpolyposis colorectal cancer (HNPCC); all with tumors that were high MSI, low MSI, or that lacked expression of any MMR protein; and a random sample of 23 with MS-stable tumors expressing all MMR proteins. Results Germline mutations were found in 18 patients (nine hMLH1, four hMSH2, four hMSH6, and one hPMS2); all tumors exhibited loss of MMR protein expression, all but one were high MSI or low MSI, and nine were from a family fulfilling Amsterdam Criteria. Sensitivities of IHC testing, MSI (high or low), and Amsterdam Criteria for MMR gene mutation were 100%, 94%, and 50%, respectively. Corresponding positive predictive values were 69%, 50%, and 75%. Conclusions Tumor IHC analysis of four MMR proteins and MSI testing provide a highly sensitive strategy for identifying MMR gene mutation–carrying, early-onset colorectal cancer patients, half of whom would have been missed using Amsterdam Criteria alone. Tumor-based approaches for triaging early-onset colorectal cancer patients for MMR gene mutation testing, irrespective of family history, appear to be an efficient screening strategy for HNPCC.


2020 ◽  
Vol 8 (A) ◽  
pp. 306-310
Author(s):  
Nour El Hoda S. Ismael ◽  
Hala M. Naguib ◽  
Suzan Mohamed Talaat ◽  
Rasha F. Bakry

BACKGROUND: Endometrial cancer (EC) is the fourth most common female cancer worldwide constituting 7% of cancer in women. It is a disease of older, postmenopausal women. The most of these patients have an identifiable source of excess estrogen, while in a small subset the pathogenesis is related to mismatch repair abnormality and lynch syndrome (LC). Mismatch repair behave as tumor suppressors and the most clinically relevant include MLH1, MSH2, MSH6, and PMS2. mutations in mismatch repair (MMR) results in a strong mutator phenotype known as microsatellite instability, which is a hallmark of LC-associated cancers. AIM: The aim of the study was to study microsatellite instability in endometrial cancer using the immunohistochemical expression of mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2). MATERIAL AND METHODS: Sixty EC cases were studied using MLH-1, MSH-2, MSH-6, and PMS-2 immunohistochemistry and their expression was correlated with different clinicopathologic parameters. RESULTS: A statistically significant relationship exists between MMR immunohistochemistry (IHC) proteins and tumor grade. Intact MMR proteins profile was associated with the lower tumor grade (31.3% were Grade 1 and 46.9% were Grade 2). Combined loss of MLH1/PMS2, combined loss of MSH2/MSH6, and isolated loss of PMS2 were also associated with the lower tumor grade while isolated loss of MSH6 was associated with the high tumor grade. However, no statistically significant correlation was found between MMR IHC proteins expression and the age of patients; tumor histopathological types, or FIGO stage. CONCLUSION: A statistically significant correlation between the tumor grade of EC cases and the MMR IHC proteins was found. Further studies are recommended to assess correlation between MMR proteins defect and different clinicopathological parameters of endometrial carcinoma.


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