Search results for "microsatellite instability"
showing 10 items of 69 documents
TP53 in gastric cancer: mutations in the l3 loop and LSH motif DNA-binding domains of TP53 predict poor outcome.
2004
The aim of this study was to clarify whether specific p53 mutations may have biological relevance in terms of disease relapse or death in gastric carcinomas (GC). Resected specimens from a consecutive series of 62 patients with GC undergoing potentially curative surgery were prospectively studied. The mutational status of exons 5-8 of the p53 gene was investigated in 62 cases using the PCR-SSCP and sequencing. Presence of microsatellite instability (MSI) was evaluated in 56 cases by analyzing loci highly sensitive of MSI. Twenty mutations of p53 were detected in 17 of the 62 cases analyzed (27%). Ten mutations (50%) occurred in highly conserved domains. According to the p53 specific functio…
Mutations in the RAS-MAPK, PI(3)K (phosphatidylinositol-3-OH kinase) signaling network correlate with poor survival in a population-based series of c…
2008
The RAS-MAPK, PI (3)K signaling pathways form a network that play a central role in tumorigenesis. The BRAF, KRAS and PI3KCA genes code 3 partners of this network and have been found to be activated by mutation in colorectal cancer; these mutations lead to unrestricted cell growth. We evaluated the clinicopathological features and the prognosis of patients with activated-network colon cancers in a population-based study. A total of 586 colon adenocarcinomas were evaluated using sequencing for mutations of KRAS and PI3KCA, and allelic discrimination for mutation of BRAF. Clinicopathological characteristics were correlated to the risk of bearing a mutation of the network using logistic regres…
Hypermethylator phenotype in sporadic colon cancer: study on a population-based series of 582 cases.
2008
Abstract The CpG island methylator phenotype (CIMP) is a distinct phenotype in colorectal cancer, associated with specific clinical, pathologic, and molecular features. However, most of the studies stratified methylation according to two subgroups (CIMP-High versus No-CIMP/CIMP-Low). In our study, we defined three different subgroups of methylation (No-CIMP, CIMP-Low, and CIMP-High) and evaluated the prognostic significance of methylation status on a population-based series of sporadic colon cancers. A total of 582 colon adenocarcinomas were evaluated using methylation-specific PCR for 5 markers (hMLH1, P16, MINT1, MINT2, and MINT31). No-CIMP status was defined as no methylated locus, CIMP-…
Interassay and interobserver comparability study of four programmed death-ligand 1 (PD-L1) immunohistochemistry assays in triple-negative breast canc…
2021
Different immunohistochemical programmed death-ligand 1 (PD-L1) assays and scorings have been reported to yield variable results in triple-negative breast cancer (TNBC). We compared the analytical concordance and reproducibility of four clinically relevant PD-L1 assays assessing immune cell (IC) score, tumor proportion score (TPS), and combined positive score (CPS) in TNBC. Primary TNBC resection specimens (n = 104) were stained for PD-L1 using VENTANA SP142, VENTANA SP263, DAKO 22C3, and DAKO 28–8. PD-L1 expression was scored according to guidelines on virtual whole slide images by four trained readers. The mean PD-L1 positivity at IC-score ≥1% and CPS ≥1 ranged between 53% and 75% with th…
High miR-21 expression from FFPE tissues is associated with poor survival and response to adjuvant chemotherapy in colon cancer
2013
Colon cancer (CC) is a leading cause of cancer mortality. Novel biomarkers are needed to identify CC patients at high risk of recurrence and those who may benefit from therapeutic intervention. The aim of this study is to investigate if miR-21 expression from RNA isolated from formalin-fixed paraffin-embedded (FFPE) tissue sections is associated with prognosis and therapeutic outcome for patients with CC. The expression of miR-21 was measured by quantitative reverse transcriptase-polymerase chain reaction in a Japanese cohort (stage I-IV, n = 156) and a German cohort (stage II, n = 145). High miR-21 expression in tumors was associated with poor survival in both the stage II/III Japanese (p …
How we treat metastatic colorectal cancer.
2020
Colorectal cancer is the second leading cause of cancer-related death worldwide. About 20% of patients suffer from metastatic disease at diagnosis, while about one-third of patients treated with curative intent relapsed. In these patients, an accurate staging allows to plan a treatment strategy within a multidisciplinary team in order to achieve predefined goals. Patient's clinical features, tumour characteristics and molecular profile (RAS/BRAF and microsatellite instability (MSI) status) should be considered during the treatment choice. Combination of chemotherapy (fluoropyrimidines, oxaliplatin and irinotecan) plus biological agents (antiepidermal growth factor receptor or antiangiogenic…
Assessing molecular subtypes of gastric cancer: microsatellite unstable and Epstein-Barr virus subtypes. Methods for detection and clinical and patho…
2018
Background The molecular classification of gastric cancer recognises two subtypes prone to immune checkpoint blockade: the microsatellite unstable and the Epstein-Barr virus (EBV)-related tumours. We aim to assess the concordance between immunohistochemistry and PCR for microsatellite status evaluation, and explore the value of microsatellite instability (MSI) and EBV as predictive survival factors. Material and methods We collected 246 consecutively diagnosed gastric cancer cases in all stages and evaluated the microsatellite status using immunohistochemistry for mismatched repair (MMR) proteins and PCR. EBV expression was studied through in situ hybridisation. Results Forty-five (18%) cas…
In the literature: October 2020.
2020
Immune checkpoint inhibitors are widely used as treatment for an increasing number of solid tumours. Nevertheless, the lack of predictive biomarker represents a limitation across several cancer types. During the last years, the possibility to dynamically study tumour evolution through circulating tumour DNA (ctDNA) in plasma has opened novel possibility in evaluating disease status and therapeutic response, especially in localised disease to predict the possibility of relapse. However, the specific opportunities for application in the context of immunotherapy remain to be clarified.1 In an article recently published in Cancer Discovery by Zhang et al ,2 a comprehensive analysis of ctDNA dat…
In the literature: October 2018
2018
Several trials with the check-point inhibitors pembrolizumab or nivolumab demonstrated some antitumour efficacy in chemorefractory advanced gastric cancer with a response rate ranging from 10% to 26%. However, no clear predictive biomarkers were found to facilitate a proper selection of patients. A series of 61 patients with advanced gastric cancer received second-line or third-line treatment with pembrolizumab in a prospective phase 2 trial.1 In a cooperative effort carried out by Korean and American investigators, a molecular characterisation of all tumours was performed including whole-exome sequencing and RNA sequencing of tissue biopsies, as well as circulating tumour DNA (ctDNA) from …
In the literature: December 2018
2018
The current development of immune checkpoint modulatory treatments has shown durable responses in the treatment of multiple cancer types.1 However, predictive biomarkers beyond PD-1 ligand 1 (PD-L1) expression and high microsatellite instability (MSI-H) to stratify patients and identify those who could benefit of these therapies are needed. In this sense, a recent study published in Science by Cristescu et al 2 describes the potential usefulness of combining the tumour mutational burden (TMB) and the T cell-inflamed gene expression profile (GEP) to jointly predict clinical response to pembrolizumab. Both PD-L1 and the GEP represent a T cell-inflamed tumour microenvironment (TME), whereas TM…