Search results for "microsatellite instability"
showing 10 items of 69 documents
Distinct Mutational Profile of Lynch Syndrome Colorectal Cancers Diagnosed under Regular Colonoscopy Surveillance
2021
Regular colonoscopy even with short intervals does not prevent all colorectal cancers (CRC) in Lynch syndrome (LS). In the present study, we asked whether cancers detected under regular colonoscopy surveillance (incident cancers) are phenotypically different from cancers detected at first colonoscopy (prevalent cancers). We analyzed clinical, histological, immunological and mutational characteristics, including panel sequencing and high-throughput coding microsatellite (cMS) analysis, in 28 incident and 67 prevalent LS CRCs (n total = 95). Incident cancers presented with lower UICC and T stage compared to prevalent cancers (p <
Molecular markers and biological targeted therapies in metastatic colorectal cancer: expert opinion and recommendations derived from the 11th ESMO/Wo…
2010
The article summarizes the expert discussion and recommendations on the use of molecular markers and of biological targeted therapies in metastatic colorectal cancer (mCRC), as well as a proposed treatment decision strategy for mCRC treatment. The meeting was conducted during the 11th ESMO/World Gastrointestinal Cancer Congress (WGICC) in Barcelona in June 2009. The manuscript describes the outcome of an expert discussion leading to an expert recommendation. The increasing knowledge on clinical and molecular markers and the availability of biological targeted therapies have major implications in the optimal management in mCRC. 21 Suppl 6 vi1 10
Exome and immune cell score analyses reveal great variation within synchronous primary colorectal cancers
2019
BACKGROUND: Approximately 4% of colorectal cancer (CRC) patients have at least two simultaneous cancers in the colon. Due to the shared environment, these synchronous CRCs (SCRCs) provide a unique setting to study colorectal carcinogenesis. Understanding whether these tumours are genetically similar or distinct is essential when designing therapeutic approaches. METHODS: We performed exome sequencing of 47 primary cancers and corresponding normal samples from 23 patients. Additionally, we carried out a comprehensive mutational signature analysis to assess whether tumours had undergone similar mutational processes and the first immune cell score analysis (IS) of SCRC to analyse the interplay…
Patterns of K-ras mutation in colorectal carcinomas from Iran and Italy (a Gruppo Oncologico dell'Italia Meridionale study): influence of microsatell…
2006
Background: K-ras mutations are a key step in colorectal cancer progression. Such mutations have been widely studied in case series from Western countries but there are few data on the rate and spectrum of mutations in tumors from countries where the epidemiological features of the disease are different. Patients and methods: Tumor samples from 182 Iranian colorectal cancer patients (170 sporadic cases and 12 HNPCC cases) were screened for K-ras mutations at codons 12, 13 and 61 by sequencing analysis. The cases were also characterized for microsatellite instability at mononucleotide repeats by PCR and fragment analysis, and classified according to microsatellite instability status. The fre…
Pharmacokinetic and metabolism determinants of fluoropyrimidines and oxaliplatin activity in treatment of colorectal patients
2011
Fluoropyrimidines and oxaliplatin continued to be the mainstay of therapeutic regimens in the treatment of colorectal cancer (CRC). For this reason, pharmacokinetic and metabolism of these drugs were analyzed and the identification of accurate and validated predictive, prognostic and toxicity markers became necessary to develop an effective therapy adapted to the patient's molecular profile, while minimizing life-threatening toxicities. In this review, we discuss literature data, defining predictive and prognostic markers actually identified in the treatment of CRC. We analyzed predictive markers of fluoropyrimidines effectiveness, principally for 5-Fluorouracil (5-FU) and also for oral flu…
<i>BRAF</i> Mutation Testing in Lynch Syndrome Diagnostics: Performance and Efficiency According to Patient's Age
2019
Background: BRAF V600E mutations are reportedly associated with sporadic microsatellite-unstable (MSI) colorectal cancer (CRC), while rarely detected in CRCs of Lynch syndrome (LS) patients. Therefore, current international diagnostic guidelines recommend somatic BRAF mutation testing in MLH1-deficient MSI CRC patients to exclude LS. As sporadic BRAF- mutant MSI CRC is a disease of the elderly, while LS-associated CRC usually occurs at younger age, we hypothesized that the efficacy of BRAF testing in LS diagnostics may be age-dependent. Methods: We systematically compared the prevalence of BRAF mutations in LS-associated CRCs and MSI CRCs from population-based cohorts in different age group…
Helicobacter pylori and Epstein–Barr Virus Co-Infection in Gastric Disease: What Is the Correlation with p53 Mutation, Genes Methylation and Microsat…
2023
Genetic predisposition, environmental factors, and infectious agents interact in the development of gastric diseases. Helicobacter pylori (Hp) and Epstein–Barr virus (EBV) infection has recently been shown to be correlated with these diseases. A cross-sectional study was performed on 100 hospitalized Italian patients with and without gastric diseases. The patients were stratified into four groups. Significant methylation status differences among CDH1, DAPK, COX2, hMLH1 and CDKN2A were observed for coinfected (Hp-EBV group) patients; particularly, a significant presence of COX2 (p = 0.0179) was observed. For microsatellite instability, minor stability was described in the Hp-HBV group (69.23…
Expression of a mutant HSP110 sensitizes colorectal cancer cells to chemotherapy and improves disease prognosis
2011
Heat shock proteins (HSPs) are necessary for cancer cell survival. We identified a mutant of HSP110 (HSP110ΔE9) in colorectal cancer showing microsatellite instability (MSI CRC), generated from an aberrantly spliced mRNA and lacking the HSP110 substrate-binding domain. This mutant was expressed at variable levels in almost all MSI CRC cell lines and primary tumors tested. HSP110ΔE9 impaired both the normal cellular localization of HSP110 and its interaction with other HSPs, thus abrogating the chaperone activity and antiapoptotic function of HSP110 in a dominant-negative manner. HSP110ΔE9 overexpression caused the sensitization of cells to anticancer agents such as oxaliplatin and 5-fluorou…
Microsatellite Instability in Colorectal Cancer: Time to Stop Hiding!
2011
Colorectal cancer (CRC) is the second cause of cancer-related death worldwide. Surgery constitutes the primary therapy for these tumors, together with chemotherapy that is usually recommended in patients with metastatic primary CRC. Although molecularly distinct entities arising from different physiopathogenic mechanisms - microsatellite (MSI) and chromosomal instability (also called microsatellite stable, MSS) - have been characterized in CRC, there is still no specific therapeutic approach that takes into account disease’s molecular heterogeneity [1]. MSI is observed in 1015% of sporadic CRCs. MSI CRCs displayed particular morphologic features, with greater predilection for the right colo…
Irinotecan or oxaliplatin: Which is the first move for the mate?
2020
Objectives: The aim of the present review is to discuss the potential link between RAS, BRAF and microsatellite instability (MSI) mutational patterns and chemotherapeutic agent efficacy [Irinotecan (IRI) vs. Oxaliplatin (OXA)], and how this can potentially influence the choice of the chemotherapy backbone. Methods: Following a review of the research literature, all pertinent articles published in the core journals were selected for the study. The inclusion criteria regarded relevant clinical and pre-clinical studies on the topic of interest (Relationship of OXA and IRI to KRAS/BRAF mutations and MSI). Results: Excision repair cross complementation group 1 (ERCC1) expression is inhibited by…