Mismatch repair protein loss and microsatellite instability in cholangiocarcinoma.

2014 ◽  
Vol 32 (3_suppl) ◽  
pp. 237-237 ◽  
Author(s):  
Lipika Goyal ◽  
Vikram Deshpande ◽  
Daniel C Chung ◽  
Ryan Thomas Groeschl ◽  
T. Clark Gamblin ◽  
...  
Keyword(s):  
Microsatellite Instability ◽  
Mismatch Repair ◽  
Massachusetts General Hospital ◽  
Positive Lymph Node ◽  
Clinicopathologic Features ◽  
Protein Loss ◽  
Tissue Samples ◽  
Dna Mismatch ◽  
Initial Cohort ◽  
History Of

237 Background: Hereditary nonpolyposis colorectal cancer (HNPCC), or Lynch Syndrome, is an autosomal dominant syndrome characterized by mutations in genes involved in DNA mismatch repair (MMR) and consequent microsatellite instability (MSI). These genetic aberrations lead to an increased incidence of multiple malignancies including colorectal and endometrial cancer, among others. While an association between biliary tumors and HNPCC has been proposed, no published studies have documented MMR protein loss and MSI in a series of biliary tumor samples. After diagnosing cholangiocarcinoma (CCA) in two clinic patients known to have HNPCC and incidentally noting MMR protein loss and MSI in their tumor, we conducted an exploratory study to evaluate the frequency of MMR protein loss and MSI in patients with CCA. Methods: Discarded tissue samples from patients with CCA treated at the Massachusetts General Hospital (n=44) were evaluated for the loss of MLH1, PMS2, MSH2, and MSH6 with immunohistochemical staining. The results were correlated with clinicopathologic features, and the MSI status was collected from the medical record. Results: Four (9.1%) of 44 patients were found to have loss of at least two MMR proteins: 2 pts had MSH2/MSH6 loss, 1 had MLH1/PMS2 loss, and 1 had loss of all 4 proteins. Two patients had previously been tested for microsatellite instability and both were MSI-high. The clinicopathologic features of the 4 patients included: median age 54.5 yo; M:F 1:3; diagnosed with ≥ 1 HNPCC-related malignancy 1/4; family history of ≥ 2 HNPCC-related tumors 2/4, intrahepatic:extrahepatic CCA 3:1; moderately-poorly:poorly differentiated 2:2; T1:T2 3:1; ≥1 positive lymph node 1/4; lymphovascular invasion 2/3; perineural invasion 2/4. Conclusions: MMR protein loss was discovered in 9.1% of patients with CCA in this initial cohort. A second validation cohort from a different institution is currently being tested, and the results will be presented at the meeting. CCA may be an underappreciated co-morbid neoplasm in the spectrum of tumors for HNPCC. MMR protein loss should be further explored as a mechanism of oncogenesis in CCA, and clinicians should be aware of this malignancy in surveillance of patients with HNPCC.

scholarly journals THE STUDY OF MISMATCH REPAIR IN ENDOMETRIAL CANCER PATIENTS WITH A FAMILY HISTORY OF CANCER

2015 ◽  
Vol 37 (4) ◽  
pp. 272-276 ◽  
Author(s):  
L G Buchynska ◽  
O Brieieva ◽  
K N Nekrasov ◽  
S V Nespryadko
Keyword(s):  
Endometrial Cancer ◽  
Family History ◽  
Microsatellite Instability ◽  
Mismatch Repair ◽  
Molecular Mechanisms ◽  
Tissue Samples ◽  
Family History Of Cancer ◽  
The Family ◽  
History Of ◽  
History Of Cancer

Aim: To assess the expression of mismatch repair (MMR) proteins MSH2 and MLH1 and carry out microsatellite analysis in patients with endometrial cancer (EC) with regard to the family history of cancer. Materials and Methods: Morphological and immunohistochemical study was performed on tumor tissue samples of 49 EC patients. Microsatellite instability was determined using PCR with primers which flank microsatellite region BAT-26. Results: A tendency to a decreased expression of both MSH2 and MLH1 markers in a group of EC patients with a family history of cancer as compared with a group without aggregation of cancer in family history was observed (labeling index — LI — was 36.1 ± 8.1% and LI 20.7 ± 9.1% versus LI 48.0 ± 5.8% and 33.8 ± 5.8%, respectively). It was determined that the number of EC patients with tumors deficient by expression of MMR markers was reliably higher in a group of patients with a family history of cancer than in a group of patients without aggregation of cancer in fami ly history (р < 0.05). It was shown that in a group of EC patients with a family history of cancer, MMR-proficient tumors were detected in 38.5% of cases. Microsatellite instability was determined in 10.7% of EC patients including one patient with aggregation of Lynch-associated tumors in family history. Conclusion: Family history of cancer of EC patients is associated with malfunctioning of the MMR system as well as may be related to alternative molecular mechanisms.

scholarly journals The Frequency of DNA Mismatch Repair Deficiency Is Very Low in Surgically Resected Lung Carcinoma

2021 ◽  
Vol 11 ◽  
Author(s):  
Naoki Yanagawa ◽  
Noriyuki Yamada ◽  
Ryo Sugimoto ◽  
Mitsumasa Osakabe ◽  
Noriyuki Uesugi ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Protein Expression ◽  
Microsatellite Instability ◽  
Cell Carcinoma ◽  
Mismatch Repair ◽  
Squamous Cell ◽  
Lung Carcinoma ◽  
The Other ◽  
Dna Mismatch ◽  
Mmr Deficiency

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.

scholarly journals Mismatch Repair Protein Loss as a Prognostic and Predictive Biomarker in Breast Cancers Regardless of Microsatellite Instability

2018 ◽  
Vol 2 (4) ◽  
Author(s):  
Nicola Fusco ◽  
Gianluca Lopez ◽  
Chiara Corti ◽  
Chiara Pesenti ◽  
Patrizia Colapietro ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Microsatellite Instability ◽  
Mismatch Repair ◽  
Statistical Tests ◽  
Immune Checkpoint Blockade ◽  
Breast Cancers ◽  
Breast Cancer Patients ◽  
Protein Loss ◽  
Clinical Value ◽  
Msi Analysis

Abstract Background Breast cancers that harbor mismatch-repair (MMR) deficiency and/or microsatellite instability (MSI) might be sensitive to immune checkpoint blockade, but there are currently no specific guidelines for assessing MMR status in breast cancer. Here, we sought to define the clinical value of MMR immunohistochemistry (IHC) and MSI analysis in breast cancers. Methods We subjected 444 breast cancers to MMR IHC and MSI analysis. Cases were classified as MMR-proficient (pMMR), MMR-deficient (dMMR), and MMR-heterogeneous (hMMR) based on the loss of immunoreactivity; MSI was defined by instability in the five indicators recommended by the National Cancer Institute for endometrial and colorectal cancers. Correlation of MMR status with patients’ survival was assessed using the Kaplan-Meier estimator. Statistical tests were two-sided. Results Loss of MMR proteins was homogeneous (dMMR) in 75 patients (17%) and heterogeneous (hMMR) in 55 (12%). Among luminal breast cancers, there were similar frequencies of dMMR and hMMR tumors. Overall, the rate of discrepancy between IHC and MSI analysis was high (91%). Women with Luminal B-like dMMR carcinomas (n = 44) showed shorter overall survival (median = 77 months, range = 0–115 months) than those with pMMR (n = 205) or hMMR (n = 35) tumors (median = 84 months, range = 0–127 months) (P = .008). On the contrary, patients with estrogen receptor-negative breast cancers treated with chemotherapy lived longer in cases of dMMR (n = 9) than pMMR (n = 33) or hMMR (n = 7) tumors, with 87 months of median survival (range = 73–123 months) for the former compared with 79 months (range = 8–113 months) for the latter two categories (P < .001). Conclusions Immunohistochemistry and MSI are not interchangeable tests in breast carcinomas. MMR protein loss is a more common event than MSI and shows intra-tumor heterogeneity. MMR IHC allows the identification of clinically relevant subclasses of breast cancer patients, provided that multiple areas of the tumor are analyzed.

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