Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “molecular stratification”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

ABCB1 Polymorphisms Influence on Temozolomide Resistance and Overall Survival in Glioblastoma Patients: A Systematic Review of Clinical Evidence.

Glioblastoma (GB), defined as IDH-wildtype CNS WHO grade 4 tumour according to the 2021 WHO classification of CNS tumours, remains a uniformly lethal malignancy in which the efficacy of temozolomide (TMZ) continues to be constrained by both intrinsic tumur biology and the pharmacological barrier imposed by the blood-brain barrier (BBB). Given the central role of the ABCB1 (MDR1/P-glycoprotein) efflux transporter in regulating CNS drug disposition, germline variation in ABCB1 has been proposed as a potential determinant of interindividual variability in TMZ response. This systematic review synthesised clinical evidence from four independent studies, encompassing more than 400 GB patients, evaluating the association between ABCB1 polymorphisms and TMZ efficacy and patients' survival. Across the available literature, the influence of ABCB1 genetic variation emerged as limited and inconsistent. An early study reported a marked survival advantage for carriers of the ABCB1 C1236T C/C genotype treated with TMZ, suggesting reduced efflux and enhanced drug exposure. However, subsequent investigations, including epigenetic analyses, high-quality multivariate survival modelling and a pharmacokinetic study demonstrating genotype-dependent differences in plasma TMZ concentrations, did not replicate a corresponding survival effect. Across the remaining cohorts, common variants such as 1236C>T, 2677G>T/A, 3435C>T and 1199G>A showed no robust association with clinical outcome, indicating that transporter-mediated modulation is likely overshadowed by dominant prognostic drivers, including MGMT methylation, IDH status and tumour heterogeneity. Collectively, current evidence does not support ABCB1 polymorphisms as reliable predictive biomarkers of TMZ response in GB. Nonetheless, the pharmacokinetic signals observed, together with emerging technologies capable of selectively modulating efflux activity at the tumour-BBB interface, point to a continued role for ABCB1 in future therapeutic strategies. Integration of transporter genomics with spatial pharmacokinetics and molecular stratification will be essential to refine drug delivery and improve outcomes in GB.

Humans↗

Systemic treatment of advanced pancreatic cancer: A Comprehensive Review.

IMPORTANCE: Pancreatic adenocarcinoma (PDAC) is an uncommon but potentially catastrophic diagnosis with historically poor prognosis. It is the tenth most prevalent cancer in the US & UK. Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies worldwide, with a five-year survival rate of approximately 10%. Despite increasing understanding of its molecular biology, systemic treatment options for advanced disease remain limited, and survival outcomes have improved only modestly over the past decade. OBSERVATIONS: This narrative review traces the evolution of systemic therapy for advanced PDAC from gemcitabine monotherapy through the landmark FOLFIRINOX (PRODIGE trial) and gemcitabine/nab-paclitaxel (MPACT trial) combination regimens, which remain the standard of care. Second-line options including liposomal irinotecan plus 5-FU/LV (NAPOLI-1) and maintenance olaparib for germline BRCA1/2-mutated disease (POLO) are also reviewed. Emerging data on sequential treatment strategies (SEQUENCE trial), biomarker-driven treatment selection (PRIMUS-001, PASS-01), and precision medicine approaches targeting actionable molecular subgroups, including dMMR/MSI-H, NTRK fusions, and homologous recombination deficiency are discussed. Real-world evidence comparing FOLFIRINOX and gemcitabine/nab-paclitaxel is critically appraised, including the challenges of patient selection, tolerance, and applicability outside clinical trial settings. CONCLUSION AND RELEVANCE: Despite incremental progress, the treatment landscape of advanced PDAC remains challenging. Molecular stratification and biomarker-driven precision oncology represent the most promising path forward. This review serves as a clinical reference for physicians managing advanced pancreatic cancer, highlighting current evidence, evidence limitations, and future research priorities including prospective biomarker-driven trials and improved access to genomic testing.

Biomarkers↗

Redox Regulation in Glioblastoma: Mechanisms, Biomarkers, and Therapeutic Implications.

Glioblastoma is the most aggressive primary tumor of the central nervous system, characterized by high invasiveness, rapid progression, and a poor prognosis despite the current treatment modalities. Molecular stratification, using biomarkers such as IDH1, TERT, and MGMT, is a crucial step in the 2021 WHO classification for improving diagnosis and prognosis. Oxidative stress, a feature of GB, has been identified as an important factor in the initiation, progression, and resistance to treatment. It occurs due to an imbalance between reactive oxygen species generated by mitochondrial metabolism, NADPH oxidases, and exogenous sources such as ionizing radiation and xenobiotics and antioxidant defense. This imbalance leads to DNA damage, genomic instability, and deregulation of signaling pathways involved in cell proliferation, apoptosis, and tumor progression. This review provides an overview of key oxidative stress biomarkers and their dual roles in tumor suppression and progression. It highlights how oxidative stress contributes to treatment responses and resistance to current GB treatments, including redox-adaptive mechanisms such as the Nrf2-Keap1 pathway, which promotes radioresistance. Finally, it discusses the potential of understanding these mechanisms to develop therapeutic strategies that target redox balance and homeostasis, aiming to overcome resistance and improve survival outcomes for glioblastoma patients.

Humans↗

Stage II (N1) lung cancer.

As therapies evolve and mature, the authors predict that the next 20 years will see significant advances in the understanding of non-small-cell lung cancer (NSCLC), in molecular stratification of NSCLC, and significant improvement in survival and cure rates. This survival will be achieved through early detection and combined treatments using effective surgical interventions, improved radiotherapeutics, and especially significantly enhanced, rationally designed systemic therapies.

Carcinoma, Non-Small-Cell Lung↗

A molecular approach to the stratification of cardiovascular risk in families with Marfan's syndrome.

BACKGROUND: The fibrillin gene encodes a protein in the extracellular matrix, and this protein is widely distributed in elastic tissues. The fibrillin gene is the site of mutations causing Marfan's syndrome. This disorder shows a high degree of clinical variability both between and within families. Each family appears to have a unique mutation in the fibrillin gene, which precludes the routine use of mutation screening for presymptomatic diagnosis of the disorder. The goal of this study was to develop a widely applicable method of molecular diagnosis. METHODS: We used three newly characterized intragenic sites of normal DNA repeat-sequence variation (i.e., polymorphisms) as markers to follow the inheritance pattern of specific copies (alleles) of the fibrillin gene in multiple kindreds with various clinical features of Marfan's syndrome. RESULTS: The polymorphic markers allowed identification of the particular copy of the fibrillin gene that cosegregated with Marfan's syndrome in 13 of the 14 families tested. In 11 families a definite presymptomatic diagnosis of Marfan's syndrome could be made in family members who had only equivocal manifestations of the disorder. In two other families, some family members demonstrated either classic Marfan's syndrome or a milder but closely related phenotype. The copy of the fibrillin gene that cosegregated with classic Marfan's syndrome was not inherited by family members with the latter, atypical, form of the disease. These milder phenotypes, previously diagnosed as Marfan's syndrome, were not associated with aortic involvement. CONCLUSIONS: These results document the usefulness of novel polymorphic DNA repeat sequences in the presymptomatic diagnosis of Marfan's syndrome. Our findings also demonstrate that the various clinical phenotypes seen in selected families may be due not to single fibrillin mutations, but rather to different genetic alterations. These findings underscore the need for a modification of the current diagnostic criteria for Marfan's syndrome in order to achieve accurate risk assessment.

Alleles↗

Squamous cell metaplasia in the human lung: molecular characteristics of epithelial stratification.

Squamous cell metaplasia (SCM) is a frequent epithelial alteration of the human tracheobronchial mucosa. This review pays particular attention to the fact that SCM can mimic esophageal, and in some instances even skin-type differentiation, showing striking similarities not only in morphology but also in terms of gene expression. Therefore, characterization of this dynamic process lends insight into the process of stratification, squamous cell formation, and "keratinization" in a pathologically relevant in vivo situation in man. First, the concept of metaplasia is presented with certain historical viewpoints on histogenesis. Then, the morphological characteristics of normal bronchial epithelium are compared with the altered phenotype of cells in SCM. These changes are described as a disturbance of the finely tuned balance of differentiation and proliferation through the action of a variety of extrinsic and intrinsic factors. Molecular aspects of altered cell/cell and cell/extracellular matrix interactions in stratified compared with single-layered epithelia are discussed with reference to SCM in the lung. Intracellular organizational and compositional changes are then summarized with special emphasis on the differential distribution of the cytokeratin (CK) polypeptides. Finally, the still unresolved problems of the histogenetic relationships between normal bronchial mucosa, SCM, and pulmonary neoplasms are addressed. As these questions remain open, examples for detection of well defined "markers" are provided that may be employed as objective criteria for determining clinically important cellular differentiation features.

Cell Differentiation↗

Thrombus Metabolism-Based Molecular Subtyping for Prognostic Risk Stratification in Acute Ischemic Stroke: A Preliminary Study.

AIMS: To preliminarily characterize metabolic molecular subtypes of cerebral thromboemboli and evaluate their clinical significance in anterior circulation acute ischemic stroke due to large vessel occlusion (AIS-LVO). METHODS: Untargeted metabolomics was performed on thromboemboli retrieved from 36 patients with anterior circulation AIS-LVO using ultra-performance coupled liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Unsupervised hierarchical clustering was employed to identify distinct metabolic molecular subtypes, and their associations with stroke etiology, radiographic severity, and functional outcomes were analyzed. RESULTS: Two distinct thrombus metabolic molecular subtypes (C1 and C2) were identified based on 12 metabolites significantly associated with both short-term (7-day ∆NIHSS) and long-term (90-day mRS) functional outcomes. The C1 subtype, predominantly cardioembolic, exhibited enhanced lipid metabolism, whereas the C2 subtype, primarily atherothrombotic, demonstrated increased folate metabolism. Patients with C1 thromboemboli presented more severe admission ischemic lesions (as indicated by ASPECTS) and experienced poorer short-term and long-term outcomes. A six-metabolite signature derived from LASSO regression was identified for exploratory discrimination of thrombus metabolic subtypes, etiological subtypes, and 90-day outcomes. CONCLUSION: This preliminary exploratory study identifies two metabolically distinct thrombus molecular subtypes with clinical implications in anterior circulation AIS-LVO, providing a novel basis for risk stratification and personalized secondary prevention and warrants further investigation.

Humans↗

[Risk stratification in medulloblastoma: screening for molecular markers].

BACKGROUND: The present study evaluates molecular markers for patients at risk of poor or no response to medulloblastoma. The aim of the study is to optimize therapy stratification. PATIENTS AND METHODS: 69 snap-frozen medulloblastoma samples were examined. C-MYC amplification was determined by fluorescence in situ hybridisation (FISH) analysis. Methylation specific PCR revealed the level of promoter methylation status of the tumor suppressor genes CASP8 (Caspase 8), TIMP3, CDH1 (E-Cadherin), CDKN2A (p16) and MGMT. Expression of GAS7 was evaluated by RT-PCR. RESULTS: C-MYC amplification: 4/69 tumors displayed high level amplification; 53/69 tumors displayed low level (< 4 copies) or no amplification; 12/69 samples were not predictive. In patients with c-MYC amplification a tendency towards unfavorable outcome was observed (p = 0.3). Promoter methylation status: CASP8: in 36/40 tumors methylated; TIMP3: 1/38 methylated; MGMT 0/44 methylated; CDKN2A: 1/46 methylated; E-cadherin 3/36 methylated; no association between methylation status and clinical outcome. GAS7: Detection of specific RNA in 20/29 medulloblastoma samples. CONCLUSION: No significant association between amplification of c-MYC and clinical outcome was observed. Promoter methylation of tumor suppressor genes is non-randomly distributed with a high level of methylation of CASP8. Recent studies show that silencing of CASP8 by methylation could be overcome by interferon gamma providing a possible therapeutic mechanism. GAS7 was shown to be a marker of mature neuronal cells with potential antitumorigenic capacity in neuronal tumors. In medulloblastoma 20/29 of the tumors examined express GAS7. Therefore a tumor suppressing function of GAS7 is improbable.

Biomarkers, Tumor↗

Adjuvant CDK4/6 inhibitors in early-stage breast cancer: Clinical evidence and considerations for risk stratification and treatment selection.

Hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer is the most common biologic subtype and carries a persistent risk of recurrence, particularly in patients with high-risk, early-stage disease. Cyclin-dependent kinase 4 and 6 inhibitors, initially established as a standard component of first-line therapy in the metastatic setting based on improvements in progression-free and overall survival, have since been evaluated in the adjuvant setting. While adjuvant palbociclib did not improve invasive disease-free survival, the monarchE and NATALEE trials demonstrated that abemaciclib and ribociclib, respectively, reduce recurrence risk in patients with high-risk, early-stage disease, with emerging overall survival data further supporting their use. However, the absolute magnitude of benefit varies substantially with baseline risk, and treatment-related toxicity and adherence challenges must be considered, as approximately 20% to 25% of patients discontinue therapy before completion. The integration of these agents into clinical practice also intersects with ongoing efforts to deescalate axillary surgery, as treatment eligibility has been largely defined by anatomic staging, particularly nodal status. Available data suggest that the incremental impact of axillary surgery on identifying candidates for cyclin-dependent kinase 4 and 6 inhibition is modest, especially among the favorable-risk populations now eligible for surgical deescalation. As the field evolves, advances in molecular risk stratification, genomic profiling, and dynamic biomarkers are poised to shift treatment selection from anatomic staging toward biologically driven approaches. Multidisciplinary decision-making that integrates tumor biology, anticipated absolute benefit, toxicity, patient preferences, and surgical considerations will be essential to ensure individualized care.

Humans↗

Cohort studies for characterizing measured genes.

We describe the advantages of using established cohort studies that have collected blood samples to investigate the role of genes in the etiology of cancer. These studies include the cost-efficiency and reliability of nested case-control substudies from the cohort for exploration of gene-disease associations and gene-environment interactions as well as gene penetrance. Also, the cohort may serve as a well-defined "mini-population" from which to study population stratification and molecular markers of ethnicity. We conclude that cohort studies can play a significant role in assessing the role of genetic markers for common tumors or multiple cancer sites.

Case-Control Studies↗

PIK3CA Polymorphisms in Cervical Cancer: Differential Impact of rs6443624 and rs141178472.

BACKGROUND: Cervical cancer remains a major cause of mortality in low- and middle-income settings. We assessed whether two PIK3CA single-nucleotide polymorphisms (SNPs) rs6443624 (A/C) and rs141178472 (C/T) are associated with disease risk, clinicopathological features, and survival. MATERIALS AND METHODS: In a prospective case control study at a tertiary center, 154 participants were enrolled (77 cases, 77 controls). Genomic DNA was isolated from FFPE cervical tumors (QIAamp DNA FFPE Tissue Kit) and genotyped using TaqMan allelic discrimination. Clinicopathological variables (FIGO stage, histology, grade, treatment, tumor-infiltrating lymphocytes [TILs]) were abstracted from records. Genotype distributions were compared by Pearson chi-square. Associations with clinicopathological features used chi-square/Fisher's exact as appropriate; ANOVA compared age across genotypes. Overall survival (OS) was estimated by Kaplan-Meier and compared with the log-rank test; mean OS with SE and 95% CI is reported. RESULTS: Cases were predominantly locally advanced at presentation and squamous histology; most were moderately differentiated. rs6443624 differed significantly between cases and controls (&#x3c7;&#xb2;=21.1, p<0.001), with CC over-represented in cases and CA less frequent. rs141178472 showed no significant case control difference (&#x3c7;&#xb2;=2.9, p=0.086). For OS, rs6443624 showed a significant genotype effect (log-rank &#x3c7;&#xb2;=23.45, p=0.001): AA had the poorest survival, CA the longest, CC intermediate. rs141178472 was not associated with OS (&#x3c7;&#xb2;=1.06, p=0.588). Genotype clinicopathological correlations for stage group, grade, TILs, and treatment were non-significant or inconsistent, with some comparisons limited by small sample sizes. CONCLUSION: The PIK3CA rs6443624 variant appears to influence both susceptibility and prognosis in cervical cancer, highlighting its potential as a biomarker for molecular risk stratification. Validation in larger, multi-center cohorts incorporating HPV/p16 assessment and extended follow-up is warranted to confirm its clinical relevance.

Humans↗

Advances in myeloma genetics and prospects for pharmacogenomic testing in multiple myeloma.

Pharmacogenomic studies in multiple myeloma, a neoplasia of clonally expanded malignant bone marrow plasma cells, are helping to set the stage for individualized therapy. Although relatively few in numbers, these studies are already providing new therapeutic targets and avenues for drug discoveries as well as contributing to novel prognostic markers in multiple myeloma. High-throughput mutation screening of the kinome promises to identify further novel targets for therapy. Genetics and gene expression profiling technology have improved molecular-based patient stratification and prognostic staging, expanded knowledge of the molecular mechanism of chemotherapeutic agents, and provided a better understanding of myeloma bone disease. The use of pharmacogenomic strategies in myeloma is thus already changing medical practice.

Humans↗

Clinical, histopathologic, and molecular markers of prognosis: toward a new disease risk stratification system for medulloblastoma.

PURPOSE: To assess the feasibility of performing central molecular analyses of fresh medulloblastomas obtained from multiple institutions and using these data to identify prognostic markers for contemporaneously treated patients. MATERIALS AND METHODS: Ninety-seven samples of medulloblastoma were collected. Tumor content in samples was judged by frozen section review. Tumor ERBB2 protein and MYCC, MYCN, and TRKC mRNA levels were measured blind to clinical details using Western blotting and real-time polymerase chain reaction, respectively. Histopathologic and clinical review of each case was also performed. All data were subjected to independent statistical analysis. RESULTS: Sample acquisition and analysis times ranged from 3 to 6 days. Eighty-six samples contained sufficient tumor for analysis, including 38 classic, 30 nodular desmoplastic, and 18 large-cell anaplastic (LCA) medulloblastomas. Protein and mRNA were extracted from 81 and 49 tumors, respectively. ERBB2 was detected in 40% (n=32 of 81) of tumors, most frequently in LCA disease (P=.005), and was independently associated with a poor prognosis (P=.031). A combination of clinical characteristics and ERBB2 expression provided a highly accurate means of discriminating disease risk. One hundred percent (n=26) of children with clinical average-risk, ERBB2-negative disease were alive at 5 years, with a median follow-up of 5.6 years, compared with only 54% for children with average-risk, ERBB2-positive tumors (n=13; P=.0001). TRKC, MYCC, and MYCN expression and histopathologic subtype were not associated with prognosis in this study. CONCLUSION: Central and rapid molecular analysis of frozen medulloblastomas collected from multiple institutions is feasible. ERBB2 expression and clinical risk factors together constitute a highly accurate disease risk stratification tool.

Adolescent↗

An international framework for clinical translation of molecular classifiers in osteosarcoma.

Despite well-recognized biological heterogeneity, osteosarcoma has been treated as a single disease for over four decades with minimal improvement in survival. Clinical features are inadequate for risk stratification, and no molecular classifiers guide therapy. An international working group evaluated candidate prognostic biomarkers for clinical translation. Pre-treatment circulating tumor DNA is positioned for clinical implementation, while additional classifiers warrant prospective validation. This work establishes a path to risk-adapted, biologically informed treatment.

Journal Article↗

Molecular characterization and expression of the stratification-related cytokeratins 4 and 15.

A number of human cytokeratins are expressed during the development of stratified epithelia from one-layered polar epithelia and continue to be expressed in several adult epithelial tissues. For studies of the regulation of the synthesis of stratification-related cytokeratins in internal tissues, we have prepared cDNA and genomic clones encoding cytokeratin 4, as a representative of the basic (type II) cytokeratin subfamily and cytokeratin 15, as representative of the acidic (type I) subfamily, and determined their nucleotide sequences. The specific expression of mRNAs encoding these two polypeptides in certain stratified tissues and cultured cell lines is demonstrated by Northern blot hybridization. Hybridization in situ with antisense riboprobes and/or synthetic oligonucleotides shows the presence of cytokeratin 15 mRNA in all layers of esophagus, whereas cytokeratin 4 mRNA tends to be suprabasally enriched, although to degrees varying in different regions. We conclude that the expression of the genes encoding these stratification-related cytokeratins starts already in the basal cell layer and does not depend on vertical differentiation and detachment from the basal lamina. Our results also show that simple epithelial and stratification-related cytokeratins can be coexpressed in basal cell layers of certain stratified epithelia such as esophagus. Implications of these findings for epithelial differentiation and the formation of squamous cell carcinomas are discussed.

Amino Acid Sequence↗