scholarly journals DNA Mismatch Repair Protein Immunohistochemistry and MLH1 Promotor Methylation Testing for Practical Molecular Classification and the Prediction of Prognosis in Endometrial Cancer

Cancers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 279 ◽  
Author(s):  
Jisup Kim ◽  
Jin Kong ◽  
Wookyeom Yang ◽  
Hanbyoul Cho ◽  
Doo Chay ◽  
...  

The incidence of endometrial cancer is rapidly increasing worldwide, and its molecular classification has gained importance for new therapeutic approaches. This study sought to examine the clinicopathologic features and immune markers associated with the DNA mismatch repair (MMR) status and MLH1 promoter methylation status of endometrial cancer patients. A total of 173 patients with primary endometrial cancer who had received a hysterectomy were evaluated for four MMR proteins (MLH1, MSH2, MSH6, and PMS2), immune markers (CD8, programmed cell death protein 1 (PD-1), and programmed death-ligand 1 (PD-L1)) and p53 by immunohistochemistry (IHC), followed by an MLH1 methylation test. Patients were classified into MMR deficiency or proficiency, sporadic cancer, or probable Lynch syndrome (PLS), and the clinicopathologic features (including the expression of peritumoral immune markers) and prognosis of each group were compared. Patients with MMR deficiency or PLS showed an increase in immune markers compared those with MMR proficiency or sporadic cancer, respectively, and PLS demonstrated higher immune marker expression than MLH1 promoter methylation. Regarding prognosis, patients with MMR deficiency showed significant adverse overall survival (OS) when in stages I and II. Practical molecular classifications based on p53 staining results, in addition to MMR or PLS status, revealed an increased predictive ability for OS compared with the European Society of Medical Oncologists (ESMO) risk groups. The results of this study suggest that PLS may be a better candidate for an immune checkpoint inhibitor than MMR deficiency. The practical molecular classification contributes not only to the screening of Lynch syndrome, but also assists in predicting the prognosis in endometrial cancer.

2020 ◽  
Vol 51 (1) ◽  
pp. 60-69 ◽  
Author(s):  
Azusa Yamamoto ◽  
Tatsuro Yamaguchi ◽  
Okihide Suzuki ◽  
Tetsuya Ito ◽  
Noriyasu Chika ◽  
...  

Abstract Background The prevalence and molecular characteristics of defective DNA mismatch repair endometrial cancers in the Japanese population have been underexplored. Data supporting clinical management of patients with Lynch-like syndrome and germline variant of uncertain significance of mismatch repair genes are still lacking. Methods Immunohistochemistry of mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) was performed on formalin-fixed paraffin-embedded sections prepared from resected primary endometrial cancers in 395 women with a median age of 59 years. Genetic and/or epigenetic alterations of the mismatch repair genes were also investigated. Results Loss of expression of one or more mismatch repair proteins was observed in 68 patients (17.2%). A total of 17 out of 68 patients (25%, 4.3% of all cases) were identified as candidates for genetic testing for Lynch syndrome after excluding 51 patients with MLH1 hypermethylated cancer. Fourteen of these 17 patients subjected to genetic testing were found to have Lynch syndrome (n = 5), germline variant of uncertain significance (n = 2) or Lynch-like syndrome (n = 7). Compared with patients with Lynch syndrome, those with germline variant of uncertain significance and Lynch-like syndrome tended to demonstrate an older age at the time of endometrial cancer diagnosis (P = 0.07), less fulfillment of the revised Bethesda guidelines (P = 0.09) and lower prevalence of Lynch syndrome-associated tumors in their first-degree relatives (P = 0.01). Conclusions This study provides useful information for management in patients with DNA mismatch repair endometrial cancer. Specifically, cancer surveillance as recommended in patients with Lynch syndrome might not be necessary in patients with germline variant of uncertain significance and Lynch-like syndrome and their relatives.


2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S116-S116
Author(s):  
R Wood ◽  
S Murray ◽  
S Offman ◽  
M Carter

Abstract Introduction/Objective Lynch syndrome (LS) is an inherited condition caused by defective DNA mismatch repair (MMR), leading to a higher incidence of cancers of multiple sites. Screening for LS is now recommended for new diagnoses of endometrial cancer (EC) using either two- (PMS2, MSH6) or four-antibody (2/4Ab) (PMS2, MSH6, MSH2, MLH1) immunohistochemical (IHC) panels. The 2Ab panel assumes consistent loss of expression of the minor dimer component, PMS2 or MSH6, when the major component, MLH1 or MSH2, respectively, is lost due to mutation. Recent studies have indicated that 2Ab testing may lead to underdiagnosis of MSH2-deficient tumors in cases where MSH6 staining is weak or focal, potentially leading to underdiagnosis of LS. Methods We conducted a retrospective study using archived slides for 293 cases of EC (identified via LIS search from 2016-2019) that were screened using the 2Ab panel (expanded to 4Ab when PMS2 or MSH6 were negative). MSH6 expression was reviewed; if weak, focal (less than 10% staining), or both, MSH2 IHC was performed. When a previously undetected loss of MSH2 expression was found, the attending clinician was informed such that referral to medical genetics could be arranged. Results Results Overall, 68 (23.2%) tumors were MMR deficient, with 54 (18.4%) showing MLH1/PMS2 loss, 7 (2.4%) with MSH2/MSH6 loss, 2 (0.7%) with isolated PMS2 loss, 4 (1.4%) with isolated MSH6 loss, and 6 (2.0%) with isolated MSH2 loss (i.e. intact but weak/focal MSH6, seen in biopsy and hysterectomy specimens). Interestingly, 1 tumor (1.5%) demonstrated loss of MSH6, MLH1 and PMS2. Two tumors (0.7%) with isolated MSH2 loss were previously unrecognized as MMR-deficient and hence at high risk for LS. Both cases were evaluated by PCR for microsatellite instability (MSI) and confirmed to have high-degree MSI. Conclusion This study identifies the frequency of mismatch repair deficient endometrial cancers in Atlantic Canada, highlights a potential pitfall of using two-stain IHC screening for Lynch syndrome, and supports emerging recommendations for universal Lynch syndrome screening in EC.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Kenta Masuda ◽  
Kouji Banno ◽  
Megumi Yanokura ◽  
Yusuke Kobayashi ◽  
Iori Kisu ◽  
...  

Some cases of endometrial cancer are associated with a familial tumor and are referred to as hereditary nonpolyposis colorectal cancer (HNPCC or Lynch syndrome). Lynch syndrome is thought to be induced by germline mutation of the DNA mismatch repair (MMR) gene. An aberration in the MMR gene prevents accurate repair of base mismatches produced during DNA replication. This phenomenon can lead to an increased frequency of errors in target genes involved in carcinogenesis, resulting in cancerization of the cell. On the other hand, aberrant DNA methylation is thought to play a key role in sporadic endometrial carcinogenesis. Hypermethylation of unmethylated CpG islands in the promoter regions of cancer-related genes associated with DNA repair leads to the cell becoming cancerous. Thus, both genetic and epigenetic changes are intricately involved in the process through which cells become cancerous. In this review, we introduce the latest findings on the DNA mismatch repair pathway in endometrial cancer.


Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3124
Author(s):  
Mikko Loukovaara ◽  
Annukka Pasanen ◽  
Ralf Bützow

The aggressiveness of mismatch repair (MMR) deficient endometrial carcinomas was examined in a single institution retrospective study. Outcomes were similar for MMR proficient (n = 508) and deficient (n = 287) carcinomas, identified by immunohistochemistry. In accordance with molecular classification based on The Cancer Genome Atlas (TCGA), tumors with abnormal p53 staining or polymerase-ϵ exonuclease domain mutation were excluded from the MMR proficient subgroup, termed as “no specific molecular profile” (NSMP). Compared with NSMP (n = 218), MMR deficiency (n = 191) was associated with poor disease-specific survival (p = 0.001). MMR deficiency was associated with an increased risk of cancer-related death when controlling for confounders (hazard ratio 2.0). In the absence of established clinicopathologic risk factors, MMR deficiency was invariably associated with an increased risk of cancer-related death in univariable analyses (hazard ratios ≥ 2.0). In contrast, outcomes for MMR deficient and NSMP subgroups did not differ when risk factors were present. Lymphatic dissemination was more common (p = 0.008) and the proportion of pelvic relapses was higher (p = 0.029) in the MMR deficient subgroup. Our findings emphasize the need for improved triage to adjuvant therapy and new therapeutic approaches in MMR deficient endometrial carcinomas.


2021 ◽  
Vol 11 ◽  
Author(s):  
Naoki Yanagawa ◽  
Noriyuki Yamada ◽  
Ryo Sugimoto ◽  
Mitsumasa Osakabe ◽  
Noriyuki Uesugi ◽  
...  

IntroductionDNA mismatch repair (MMR) deficiency leads to changes in the length of nucleotide repeat sequences of tumor DNA. In that situation, DNA replicational errors occur and accumulate during DNA replication. As a result, this mechanism frequently affects the coding regions of oncogenes and tumor suppressor genes and causes carcinogenesis. Recently, DNA MMR deficiency has been recognized as a predictive biomarker for immunotherapy. The aim of this study is to examine the frequency of DNA MMR deficiency and clinicopathological characteristics in surgically resected lung carcinoma (LC) and their correlation.MethodsA total of 1153 LCs were examined. Tissue microarrays were constructed. The status of MMR deficiency was evaluated by immunohistochemical analysis of MMR protein expression (hMLH1, hMSH2, hMSH6, and hPMS2). Microsatellite instability analysis, BRAF mutation, and MLH1 methylation analysis were performed for cases that showed MMR deficiency.ResultsOnly 2 of the 1153 cases (0.17%) showed a loss of hMLH1/hPMS2 protein expression. They also had high levels of microsatellite instability (MSI-H), had neither MLH1 promoter methylation nor BRAF mutation, and were male smokers. Histopathologically, one was a squamous cell carcinoma, and the other was combined small cell carcinoma with squamous cell carcinoma. Regarding PD-L1 protein expression, one had high expression, and the other had none.ConclusionThe frequency of MMR deficiency was very low in LC. However, our two cases were non-adenocarcinoma and differed from previous studies. Because of its very low frequency, MMR deficiency is not a practical biomarker to predict the effect of immune checkpoint inhibitors in LC.


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