KRAS Mutations In Colorectal Cancer Patients Research Articles

Aberrant Expression of Sprouty2 In Human Colon Cancer

Purpose: The study investigates the role of Sprouty2 (SPRY2) in colorectal cancer (CRC) cell function. It found that SPRY2 inhibits the RAS/MAPK/ERK pathway and promotes cancer invasion in KRAS-WT CRC. However, it did not significantly alter p-ERK levels, cell proliferation, or invasion in KRAS-mutant CRCs. High SPRY2 expression was associated with shorter cancer-specific survival in both KRAS-WT and KRAS-mutant CRC patients. The study suggests that SPRY2 may promote invasion and progression in both types of CRC. Methods: The gene expression data were retrieved from Gene Expression Omnibus (GEO). Fold change, p.value t-test and David Functional analysis, hierarchical clustering was performed. Results: In this study, we identified altered genes involved in SPRY2 mutation in the colon and the relevant pathways to understand whether the SPRY2 mutation changes cancer progression. 4 genes of 5 genes were downregulated following the mutation in colon cancer cells. We identified a network between these genes and pathways they belong to. Pathway analysis showed that these genes are mostly associated with cancer cell proliferation. Conclusion: MAL2, ESRP1, CDH3, CXCL14 and CDH1 genes were found to be associated with in SPRY2 mutation in colon cancer pathogenesis. Almost all these genes are effective in the proliferation of cancer cells, especially during the SPRY2 mutation process. Therefore, it is hypothesized that downregulation or upregulation of these genes may affect colon cancer pathogenesis by reducing cell proliferation. And it is predicted that SPRY2 mutation may be an important factor for colon cancer.

Molecular Spectrum of K-RAS Mutations in Colorectal Cancer Patients in Peshawar, Pakistan

Background: The global incidence of colorectal cancer (CRC) has surged, presenting a significant health challenge with an annual occurrence of 1.7 million cases. The American Cancer Society reports that KRAS and BRAF mutations contribute to 20-50% of CRC cases. This study addresses the gap in data on KRAS mutations in CRC patients in Peshawar, Pakistan. Objective: To determine the prevalence and types of KRAS mutations in colorectal cancer patients in Peshawar, Pakistan. Methods: This retrospective, cross-sectional study was conducted at the Nuclear Medicine, Oncology, and Radiotherapy Institute (NORI) Hospital in Islamabad from April to November 2022. DNA was extracted from formalin-fixed, paraffin-embedded tissue blocks of 58 CRC patients, regardless of age and gender, following informed verbal consent. KRAS mutation testing was performed using the Cobas Z480 Real-time thermal cycler. Results: Among the 58 CRC patients, 34 (58.6%) were females, and 24 (41.4%) were males. The highest CRC incidence (36.2%) was observed in the 11-25 years age group. KRAS mutations at codons 12 and 13 were found in 18% of cases, with all isolates carrying the G12D mutation. Kaplan-Meier analysis revealed a lower survival probability for patients with codon 12 mutations compared to those with codon 13 mutations. Conclusion: The study highlights the need for broader research on KRAS mutations across diverse ethnicities and geographical regions in Pakistan to better understand CRC prevalence and improve patient outcomes.

A multicenter study: predicting KRAS mutation and prognosis in colorectal cancer through a CT-based radiomics nomogram.

To establish a CT-based radiomics nomogram for preoperative prediction of KRAS mutation and prognostic stratification in colorectal cancer (CRC) patients. In a retrospective analysis, 408 patients with confirmed CRC were included, comprising 168 cases in the training set, 111 cases in the internal validation set, and 129 cases in the external validation set. Radiomics features extracted from the primary tumors were meticulously screened to identify those closely associated with KRAS mutation. Subsequently, a radiomics nomogram was constructed by integrating these radiomics features with clinically significant parameters. The diagnostic performance was assessed through the area under the receiver operating characteristic curve (AUC). Lastly, the prognostic significance of the nomogram was explored, and Kaplan-Meier analysis was employed to depict survival curves for the high-risk and low-risk groups. A radiomics model was constructed using 19 radiomics features significantly associated with KRAS mutation. Furthermore, a nomogram was developed by integrating these radiomics features with two clinically significant parameters (age, tumor location). The nomogram achieved AUCs of 0.834, 0.813, and 0.811 in the training set, internal validation set, and external validation set, respectively. Additionally, the nomogram effectively stratified patients into high-risk (KRAS mutation) and low-risk (KRAS wild-type) groups, demonstrating a significant difference in overall survival (P < 0.001). Patients categorized in the high-risk group exhibited inferior overall survival in contrast to those classified in the low-risk group. The CT-based radiomics nomogram demonstrates the capability to effectively predict KRAS mutation in CRC patients and stratify their prognosis preoperatively.

RAS/RAF/MAPK Pathway Mutations as Predictive Biomarkers in Middle Eastern Colorectal Cancer: A Systematic Review.

This review article aims to investigate the prevalence and spectrum of rat sarcoma (RAS) and V-Raf Murine Sarcoma Viral Oncogene Homolog B (BRAF) mutations, and their connection with geographical location, clinicopathological features, and other relevant factors in colorectal cancer (CRC) patients in the Middle East. A systematic literature review, employing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework, was conducted to investigate the association between the frequency of relevant mutations and the descriptive clinicopathological characteristics of CRC patients. Multiple electronic databases, including PubMed, Science Direct, Web of Science, Scopus, and Google Scholar, were searched to analyze the relevant literature. A total of 19 eligible studies comprising 2960 patients with CRC were included in this review. A comprehensive analysis of the collected literature data as well as descriptive and methodological insights is provided. Men were predominant in reviewed studies for the region, accounting for 58.6%. Overall, RAS mutation prevalence was 38.1%. Kirsten RAS Viral Oncogene Homolog (KRAS) mutations were the most common, accounting for 37.1% of cases and distributed among different exons, with the G12D mutation being the most frequent in exon 2 (23.2%) followed by G12V (13.7%), G13D (10.1%), G12C (5.1%), G12A (5.04%), and G12S (3.6%). Neuroblastoma RAS Viral Oncogene Homolog (NRAS) mutations were identified in 3.3% of tumor samples, with the most common mutation site located in exons 2, 3, and 4, and codon 61 being the most common location for the region. The total mutation frequency in the BRAF gene was 2.6%, with the V600E mutation being the most common. The distribution patterns of RAS and BRAF mutations among CRC patients exhibit notable variations across diverse ethnic groups. Our study sheds light on this phenomenon by demonstrating a higher prevalence of KRAS mutations in CRC patients from the Middle East, as compared with those from other regions. The identification of these mutations and geographical differences is important for personalized treatment planning and could potentially aid in the development of novel targeted therapies. The distinct distribution patterns of RAS and BRAF mutations among CRC patients across different ethnic groups, as well as the regional variability in mutation prevalence, highlight the need for further research in this area.

Erianin inhibits the growth and metastasis through autophagy-dependent ferroptosis in KRASG13D colorectal cancer.

Colorectal cancer (CRC) is the third most common cause of cancer mortality worldwide. Approximately 40% of CRC patients are KRAS sequence variation, including KRAS G13D mutation (KRASG13D) CRC patients, accounting for approximately 8% of all KRAS mutations in CRC patients and showing little benefit from anti-EGFR therapy. Therefore, there is an urgent need for new and effective anticancer agents in patients with KRASG13D CRC. Here, we identified a natural product, erianin, that directly interacted with purified recombinant human KRASG13D with a Kd of 1.1163 μM, which also significantly improve the thermal stability of KRASG13D. The cell viability assay showed that KRASG13D cells were more sensitive to erianin than KRASWT or KRASG12V cells. In vitro, results showed that erianin suppressed the migration, invasion and epithelial-mesenchymal transition (EMT) of KRASG13D CRC cells. Furthermore, erianin induced ferroptosis, as evidenced by the accumulation of Fe2+ and reactive oxygen species (ROS), lipid peroxidation, and changes in the mitochondrial morphology of KRASG13D CRC cells. Interestingly, we also found that erianin-induced ferroptosis was accompanied by autophagy. Moreover, the occurrence of erianin-induced ferroptosis is reversed by autophagy inhibitors (NH4Cl and Bafilomycin A1) and ATG5 knockdown, suggesting that erianin-induced ferroptosis is autophagy-dependent. In addition, we evaluated the inhibition of tumor growth and metastasis by erianin in vivo using a subcutaneous tumor model and a spleen-liver metastasis model, respectively. Collectively, these data provide novel insights into the anticancer activity of erianin, which is valuable for the further discussion and investigation of the use of erianin in clinical anticancer chemotherapy for KRASG13D CRC.

CT-Based Radiomics to Predict KRAS Mutation in CRC Patients Using a Machine Learning Algorithm: A Retrospective Study.

Colorectal cancer (CRC) is one of the most common types of cancer worldwide. The KRAS mutation is present in 30-50% of CRC patients. This mutation confers resistance to treatment with anti-EGFR therapy. This article aims at proving that computer tomography (CT)-based radiomics can predict the KRAS mutation in CRC patients. The piece is a retrospective study with 56 CRC patients from the Hospital of Santiago de Compostela, Spain. All patients had a confirmatory pathological analysis of the KRAS status. Radiomics features were obtained using an abdominal contrast enhancement CT (CECT) before applying any treatments. We used several classifiers, including AdaBoost, neural network, decision tree, support vector machine, and random forest, to predict the presence or absence of KRAS mutation. The most reliable prediction was achieved using the AdaBoost ensemble on clinical patient data, with a kappa and accuracy of 53.7% and 76.8%, respectively. The sensitivity and specificity were 73.3% and 80.8%. Using texture descriptors, the best accuracy and kappa were 73.2% and 46%, respectively, with sensitivity and specificity of 76.7% and 69.2%, also showing a correlation between texture patterns on CT images and KRAS mutation. Radiomics could help manage CRC patients, and in the future, it could have a crucial role in diagnosing CRC patients ahead of invasive methods.

Targeting KRAS in Colorectal Cancer: A Bench to Bedside Review.

Colorectal cancer (CRC) is a heterogeneous disease with a myriad of alterations at the cellular and molecular levels. Kristen rat sarcoma (KRAS) mutations occur in up to 40% of CRCs and serve as both a prognostic and predictive biomarker. Oncogenic mutations in the KRAS protein affect cellular proliferation and survival, leading to tumorigenesis through RAS/MAPK pathways. Until recently, only indirect targeting of the pathway had been investigated. There are now several KRAS allele-specific inhibitors in late-phase clinical trials, and many newer agents and targeting strategies undergoing preclinical and early-phase clinical testing. The adequate treatment of KRAS-mutated CRC will inevitably involve combination therapies due to the existence of robust adaptive resistance mechanisms in these tumors. In this article, we review the most recent understanding and findings related to targeting KRAS mutations in CRC, mechanisms of resistance to KRAS inhibitors, as well as evolving treatment strategies for KRAS-mutated CRC patients.

Dual role of sprouty2 as an inhibitor of RAS/ERK-driven proliferation and a promoter of cancer invasion in KRAS wild-type colorectal cancer.

Sprouty2 (SPRY2) is known to inhibit the RAS/MAPK/ERK pathway, and is a potential study target for cancer. The effect of SPRY2 in colorectal cancer (CRC) and whether it is influenced by KRAS mutation are not known. We manipulated SPRY2 gene expression and used an activating KRAS-mutant plasmid to determine its effect on CRC cell function in vitro and/or in vivo. We performed SPRY2 immunohistochemical staining in 143 CRC specimens and analyzed the staining results with various clinicopathological characteristics in relation to KRAS mutation status. SPRY2 knockdown in Caco-2 cells carrying the wild-type (WT) KRAS gene upregulated phosphorylated ERK (p-ERK) levels and increased cell proliferation in vitro, but inhibited cell invasion. However, SPRY2 knockdown in SW480 cells (activating KRAS mutant) or Caco-2 cells transfected with KRAS-mutant plasmid did not significantly alter p-ERK levels, cell proliferation, or invasion. The xenografts of SPRY2-knockdown Caco-2 cells were larger with less deep muscle invasion than those of control cells. The clinical cohort study revealed a positive association of SPRY2 protein expression with pT status, lymphovascular invasion, and perineural invasion in KRAS-WT CRCs. However, the associations were not observed in KRAS-mutant CRCs. Interestingly, high SPRY2 expression was related to shorter cancer-specific survival in both KRAS-WT and KRAS-mutant CRC patients. Our study demonstrated the dual role of SPRY2 as an inhibitor of RAS/ERK-driven proliferation and as a promoter of cancer invasion in KRAS-WT CRC. SPRY2 may promote the invasion and progression of KRAS-WT CRC, and might also enhance KRAS-mutant CRC progression through pathways other than invasion.

KRAS Mutations in Colorectal Cancer: Relationship With Clinicopathological Characteristics and Impact on Clinical Outcomes in Saudi Arabia.

BackgroundFew studies have addressed the prevalence and prognostic impacts of KRAS mutations in Saudi patients with colorectal cancer (CRC). The present study aimed to address the prevalence of KRAS mutations and evaluate their impact on clinical outcomes (if any) among Saudi patients.MethodsThis retrospective cohort study was conducted at King Saud University Medical Centre (KSUMC), Saudi Arabia. All medical records of biopsy-proven CRC patients between 2015 and 2021 were reviewed. Statistical analysis was carried out to address the associations between KRAS mutations and the clinicopathological patients’ variables and survival.ResultsKRAS mutations were found in 97/194 (50%) CRC patients. In comparison to wild type KRAS tumors, KRAS- mutated ones had shown a trend toward right-sided tumors (30% and 4.3% vs 16% and 1.1%, p-value = 0.032, respectively) and peritoneal metastases (34% vs 19%, p-value = 0.014). Older age at diagnosis, gender, tumor grade, microsatellite instability (MSI), tumor stage (T), and the presence of distant metastasis were independent prognostic factors for poor overall survival (OS). There was no significant association between KRAS mutations and the hazard of mortality (HR: 0.653, 95% CI 0.873-1.134, p = 0.131). For progression-free survival (PFS), older age at presentation, MSI, tumor nodal stage (N), the presence of liver and lung metastasis, and recurrence were poor prognostic factors for PFS. There was no significant relation between KRAS mutations and PFS (HR ratio: 0.756, 95% CI 0.229-2.497, p = 0.646).ConclusionsThe prevalence of KRAS mutations in CRC patients was similar to that observed in previous studies of Saudi patients. KRAS mutations showed a trend toward right-sided tumors and peritoneal metastases. Survival was significantly related to different clinicopathologic variables of the study cohort but was not affected by the KRAS mutational status.

HOXA7 promotes the metastasis of KRAS mutant colorectal cancer by regulating myeloid-derived suppressor cells

BackgroundKRAS mutation accounts for 30–50% of human colorectal cancer (CRC) cases. Due to the scarcity of effective treatment options, KRAS mutant CRC is difficult to treat in the clinic. Metastasis is still the major cause of the high mortality associated with KRAS mutant CRC, but the exact mechanism remains unclear. Here, we report a unique function of Homeobox 7 (HOXA7) in driving KRAS mutant CRC metastasis and explore therapeutic strategies for subpopulations of patients with this disease.MethodsThe expression of HOXA7 in a human CRC cohort was measured by immunohistochemistry. The function of HOXA7 in KRAS mutant CRC metastasis was analyzed with the cecum orthotopic model.ResultsElevated HOXA7 expression was positively correlated with lymph node metastasis, distant metastasis, poor tumor differentiation, high TNM stage, and poor prognosis in CRC patients. Furthermore, HOXA7 was an independent prognostic marker in KRAS mutant CRC patients (P < 0.001) but not in KRAS wild-type CRC patients (P = 0.575). Overexpression of HOXA7 improved the ability of KRAS mutant CT26 cells to metastasize and simultaneously promoted the infiltration of myeloid-derived suppressor cells (MDSCs). When MDSC infiltration was blocked by a CXCR2 inhibitor, the metastasis rate of CT26 cells was markedly suppressed. The combination of the CXCR2 inhibitor SB265610 and programmed death-ligand 1 antibody (anti-PD-L1) could largely inhibit the metastasis of KRAS mutant CRC.ConclusionsHOXA7 overexpression upregulated CXCL1 expression, which promoted MDSC infiltration. Interruption of this loop might provide a promising treatment strategy for HOXA7-mediated KRAS mutant CRC metastasis.

Abstract 961: FGFR3 and eIF4E are overexpressed and interact with PRMT5 and KRAS in CRC

Abstract Introduction Nearly 45% of colorectal cancer (CRC) patients harbor a mutation in their KRAS gene for which, despite many years of research, there are still no targeted therapies available. Protein Arginine Methyltransferase 5 (PRMT5) is a transcription regulator for multiple cellular processes that is currently being tested as a potential therapeutic target in several cancer types. Previous studies have shown that PRMT5 depletion leads to a reduction in FGFR3 and eIF4E expression. FGFR3 and eIF4E are oncogenes which play an important role in cellular proliferation and tumorigenesis. Furthermore, our group's previous research has demonstrated that PRMT5 inhibition shows significantly greater therapeutic effects in KRAS mutant CRC cells when compared to KRAS wild-type (WT) CRC cells. Methodology The Gene Expression Profiling Interactive Analysis (GEPIA) database was used to analyze the RNA-Seq data of CRC patients from The Cancer Genome Atlas (TCGA) database. We first used the GEPIA database to determine whether eIF4E and FGFR3 are overexpressed in colon and rectum patient tumor samples when compared to normal colon and rectum patient samples. We then used the GEPIA database to determine whether eIF4E and FGFR3 gene expression are correlated with PRMT5 and KRAS gene expression in colon and rectum patient tumor samples. We next used the STRING database to analyze whether eIF4E and FGFR3 interact with PRMT5 and KRAS. Finally, we used Biorender to develop a proposed molecular mechanism outlining how eIF4E and FGFR3 interact with PRMT5 and KRAS in CRC. Results • eIF4E is 2.4 and 2.2-Fold overexpressed in colon and rectum patient tumor samples, respectively, compared to normal colon and rectum patient samples (q &amp;lt; 0.01). • FGFR3 is 2.3 and 3.7-Fold overexpressed in colon and rectum patient tumor samples, respectively, compared to normal colon and rectum patient samples (q &amp;lt; 0.01). • eIF4E gene expression is positively correlated with PRMT5 (p &amp;lt; 0.01, R = 0.85) and KRAS (p &amp;lt; 0.01, R = 0.86) gene expression in colon and rectum patient tumor samples. • FGFR3 gene expression is positively correlated with PRMT5 (p &amp;lt; 0.01, R = 0.61) and KRAS (p &amp;lt; 0.01, R = 0.63) gene expression in colon and rectum patient tumor samples. • eIF4E and FGFR3 are shown to interact with PRMT5 and KRAS in the STRING database (Interaction score &amp;gt; 0.150). • A molecular mechanism is proposed suggesting that PRMT5 inhibition may show greater therapeutic effects in KRAS mutant CRC, when compared to KRAS WT CRC, through PRMT5's interactions with eIF4E and FGFR3. Conclusion eIF4E and FGFR3 have been shown to be overexpressed and to interact with PRMT5 and KRAS in CRC. This significant observation can be therapeutically utilized towards developing new effective treatments for KRAS mutant CRC patients. Further analysis is currently in progress to verify the proposed molecular mechanism outlining how eIF4E and FGFR3 interact with PRMT5 and KRAS in CRC. Citation Format: David Shifteh, Tzuriel Sapir, Moshe Pahmer, Sanjay Goel, Radhashree Maitra. FGFR3 and eIF4E are overexpressed and interact with PRMT5 and KRAS in CRC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 961.

Globo H expression in metastatic colorectal cancer (CRC).

3527 Background: Globo H is a carbohydrate antigen that is highly expressed on the cell surface of epithelial cancers but not in normal tissue, and has been reported to correlate with poor prognosis. An attractive therapeutic target, Globo H-targeted agents are being tested in early clinical trials (e.g., OBI-833, a Globo H antigen conjugated to a mutated diphtheria toxin with potential antineoplastic activities, and OBI-999, an antibody-drug conjugate (ADC) consisting of a Globo H monoclonal antibody with a synthetic antineoplastic agent). We aim to describe the molecular features associated with Globo H expression in CRC. Methods: A total of 7,604 CRC tumors were tested by Caris Life Sciences (Phoenix, AZ) by NextGen DNA and RNA sequencing. The expression of β3GalT5, FUT-1 and FUT-2 were evaluated as surrogates for Globo H expression as they are the key enzymes in its biosynthesis. An average z-score of the 3 genes (GloboH) and of β3GalT5 (B3) alone were calculated; tumors with top quartile z-scores were considered expression-high (Q4) and bottom quartile, expression-low (Q1). QuantiSEQ was used to assess immune cell infiltration in the tumor microenvironment (TME). Statistical significance was determined using chi-square/Fisher-Exact and adjusted for multiple comparisons (q&lt;0.05). Consensus molecular subtype (CMS) was developed using RNA seq data. Results: When the 3 genes were considered, GloboH-H tumors showed higher prevalence of CMS1 and CMS4 (23.8% vs. 12%; 38.7% vs. 29.4%) and lower prevalence of CMS2 (40% vs. 18.7%) compared to GloboH-L. Similar patterns of CMS distribution were seen for B3 alone. B3-H tumors were significantly more frequently TMB-H (&gt;=10) (11.4% vs. 8.3%), PD-L1 positive (5.7% vs. 3.4%) and MSI-H/dMMR (8.3% vs. 5.5%). Strong positive associations were seen with mutations in BRAF, KRAS, RSPO3 fusion, and cMYC amplification with B3 alone and GloboH (all q&lt;0.05). Anti-tumor CD4+ T cells and NK cells were increased in the TME with increased expression of GloboH and B3 (q&lt;0.05). However, immune suppressive neutrophils and Tregs were also increased. Dendritic cells were negatively associated with B3 expression while endothelial cells and fibroblasts showed a positive association with GloboH and B3. Conclusions: The association with TMB-H, MSI-H, and PD-L1 status suggests that in some tumors Globo H may be a promising target for combination therapy with immune checkpoint inhibition. The association with different cell populations suggests manipulating the cellular balance in the TME as an approach to improve the efficacy of treatment. NK cell checkpoint inhibitors are in clinical trials and might be utilized in high Globo H cancers; treatments inducing DCs in tumors have been shown to enhance responses to BRAF and PD-L1 blockade and might be applicable in the context of Globo H immunotherapy to overcome Treg immune suppression. Anti-Globo H vaccines and ADCs might be particularly effective in BRAF and KRAS-mutant CRC patients.

Immune landscape and prognostic immune-related genes in KRAS-mutant colorectal cancer patients

BackgroundKRAS gene is the most common type of mutation reported in colorectal cancer (CRC). KRAS mutation-mediated regulation of immunophenotype and immune pathways in CRC remains to be elucidated.Methods535 CRC patients were used to compare the expression of immune-related genes (IRGs) and the abundance of tumor-infiltrating immune cells (TIICs) in the tumor microenvironment between KRAS-mutant and KRAS wild-type CRC patients. An independent dataset included 566 cases of CRC and an in-house RNA sequencing dataset were served as validation sets. An in-house dataset consisting of 335 CRC patients were used to analyze systemic immune and inflammatory state in the presence of KRAS mutation. An immue risk (Imm-R) model consist of IRG and TIICs for prognostic prediction in KRAS-mutant CRC patients was established and validated.ResultsNF-κB and T-cell receptor signaling pathways were significantly inhibited in KRAS-mutant CRC patients. Regulatory T cells (Tregs) was increased while macrophage M1 and activated CD4 memory T cell was decreased in KRAS-mutant CRC. Prognosis correlated with enhanced Tregs, macrophage M1 and activated CD4 memory T cell and was validated. Serum levels of hypersensitive C-reactive protein (hs-CRP), CRP, and IgM were significantly decreased in KRAS-mutant compared to KRAS wild-type CRC patients. An immune risk model composed of VGF, RLN3, CT45A1 and TIICs signature classified CRC patients with distinct clinical outcomes.ConclusionsKRAS mutation in CRC was associated with suppressed immune pathways and immune infiltration. The aberrant immune pathways and immune cells help to understand the tumor immune microenvironments in KRAS-mutant CRC patients.

The value of haematological parameters and serum tumour markers for predicting KRAS mutations in 784 Chinese colorectal cancer patients: a retrospective analysis

BackgroundIdentifying the mutation status of KRAS is important for optimizing treatment in patients with colorectal cancer (CRC). The aim of this study was to investigate the predictive value of haematological parameters and serum tumour markers (STMs) for KRAS gene mutations.MethodsThe clinical data of patients with colorectal cancer from January 2014 to December 2018 were retrospectively collected, and the associations between KRAS mutations and other indicators were analysed. Receiver operating characteristic (ROC) curve analysis was performed to quantify the predictive value of these factors. Univariate and multivariate logistic regression models were applied to identify predictors of KRAS mutations by calculating the odds ratios (ORs) and their corresponding 95% confidence intervals (CIs).ResultsKRAS mutations were identified in 276 patients (35.2%). ROC analysis revealed that age, CA12–5, AFP, SCC, CA72–4, CA15–3, FERR, CYFRA21-1, MCHC, and tumor location could not predict KRAS mutations (P = 0.154, 0.177, 0.277, 0.350, 0.864, 0.941, 0.066, 0.279, 0.293, and 0.053 respectively), although CEA, CA19–9, NSE and haematological parameter values showed significant predictive value (P = 0.001, < 0.001, 0.043 and P = 0.003, < 0.001, 0.001, 0.031, 0.030, 0.016, 0.015, 0.019, and 0.006, respectively) but without large areas under the curve. Multivariate logistic regression analysis showed that CA19–9 was significantly associated with KRAS mutations and was the only independent predictor of KRAS positivity (P = 0.016).ConclusionsHaematological parameters and STMs were related to KRAS mutation status, and CA19–9 was an independent predictive factor for KRAS gene mutations. The combination of these clinical factors can improve the ability to identify KRAS mutations in CRC patients.

Development of a dual-energy spectral CT based nomogram for the preoperative discrimination of mutated and wild-type KRAS in patients with colorectal cancer

PurposeTo develop a dual-energy spectral CT (DESCT) nomogram for the preoperative identification of KRAS mutation in patients with colorectal cancer (CRC). MethodOne hundred and twenty-four patients who underwent energy spectrum CT pre-operatively were recruited and split into mutated KRAS group (n = 50) and wild-type KRAS group (n = 74). DESCT parameters, including monochromatic CT value, iodine concentration, water concentration, and effective atomic number were measured independently by two reviewers in the arterial, venous, and delayed phases. Normalized iodine concentration (NIC) and slope k of the spectral HU curve were calculated. Evaluate other imaging features such as ATL/LTL ratio, tumor gross pattern, pericolorectal fat invasion (PFI) was also performed by these reviewers. Independent predictors for KRAS mutation were screened out using logistic regression, and these predictors were presented as a nomogram. The receiver operating characteristic (ROC) curve, calibration curve and decision curve analysis (DCA) were used to evaluate the clinical usefulness of the nomogram. ResultsThe slope k in the arterial phase, effective atomic number in the arterial phase, NIC in the venous phase, ATL/LTL ratio and PFI were significant independent predictors for KRAS mutation. Based on these independent predictors, a quantitative nomogram was developed to predict individual KRAS mutation probability. The nomogram had excellent performance with an AUC of 0.848 and excellent calibration. DCA showed that our nomogram has outstanding clinical utility. ConclusionsThis study demonstrates that a DESCT based nomogram has potential value for individual preoperative identification of KRAS mutation in CRC patients.

Analysis of KRAS mutations in circulating tumor DNA and colorectal cancer tissue

ABSTRACT The mutation status of KRAS is important for anti-EGFR therapy in colorectal cancer (CRC) patients; however, detection of KRAS mutations in circulating tumor DNA (ctDNA) is problematic. We investigated tissue and plasma assays for KRAS mutations in CRC patients. The KRAS status of 407 CRC patients was evaluated using integration of amplification refractory mutation system polymerase chain reaction (PCR), melting curves and wild type DNA blocking (IAMB) in tissue and plasma samples. Disparate cases were re-evaluated by Sanger sequencing of tissue samples. General characteristics and tumor biomarkers including CEA, CA19-9 and CA125 were characterized. The prevalence of KRAS mutations was 40.8% in plasma and 49.1% in tissue. The overall percent agreement, positive percent agreement and negative percent agreement were 82.3, 76.3 and 90.8%, respectively. Older patients and higher TNM stage exhibited increased sensitivity for detecting KRAS mutations in plasma. We found 54.1% of patients with KRAS mutations using parallel analysis of tissue and plasma; only 36.4% of patients were detected by series analysis. We found that plasma based KRAS detection with IAMB technology is an alternative to tissue based KRAS testing. KRAS mutations can be identified more easily when both assays are used together

Identification of PIGU as the Hub Gene Associated with KRAS Mutation in Colorectal Cancer by Coexpression Analysis.

Colorectal cancer (CRC) patients with KRAS mutation are refractory and usually have poor prognosis. We aimed to identify the hub gene associated with KRAS mutant CRCs. Weighted gene coexpression network analysis (WGCNA) was used to calculate the key module and the hub genes in GSE39582. Combined with the protein-protein interaction (PPI) network and survival analysis, the real hub gene was identified and further validated. With the highest module significance value and correlation coefficient, the blue module was selected as the key module, 19 genes were identified as the hub gene candidates. The above genes were significantly downregulated in KRAS mutant CRCs compared with the wild type. Four genes (AAR2, PSMA7, NELFCD, and PIGU) were further screened as the potential hub genes by the PPI network. Low expression of PIGU for KRAS mutant patients had a poor prognosis. Therefore, PIGU was identified as the hub gene. PIGU expression was also downregulated in other two CRC datasets. "MAPK SIGNALING PATHWAY" was enriched in PIGU lowly expressed samples. PIGU was identified and validated to be closely related to KRAS mutation. It could be a potential prognosis biomarker and a novel treatment target for KRAS mutant CRC patients.

Nomograms for Prediction of Molecular Phenotypes in Colorectal Cancer.

BackgroundColorectal cancer (CRC) patients with different molecular phenotypes, including microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and somatic mutations in BRAF and KRAS gene, vary in treatment response and prognosis. However, molecular phenotyping under adequate quality control in a community-based setting may be difficult. We aimed to build the nomograms based on easily accessible clinicopathological characteristics to predict molecular phenotypes.MethodsThree hundred and six patients with pathologically confirmed stage I-IV CRC were included in the cohort. The assays for MSI, CIMP, and mutations in BRAF and KRAS gene were performed using resected tumor samples. The candidate predictors were identified from clinicopathological variables using multivariate Logistic regression analyses to construct the nomograms that could predict each molecular phenotype.ResultsThe incidences of MSI, CIMP, BRAF mutation and KRAS mutation were 25.3% (72/285), 2.5% (7/270), 3.4% (10/293), and 34.8% (96/276) respectively. In the multivariate Logistic analysis, poor differentiation and high neutrophil/lymphocyte ratio (NLR) were independently associated with MSI; poor differentiation, high NLR and high carcinoembryonic antigen/tumor size ratio (CSR) were independently associated with CIMP; poor differentiation, lymphovascular invasion and high CSR were independently associated with BRAF mutation; poor differentiation, proximal tumor, mucinous tumor and high NLR were independently associated with KRAS mutation. Four nomograms for MSI, CIMP, BRAF mutation and KRAS mutation were developed based on these independent predictors, the C-indexes of which were 61.22% (95% CI: 60.28–62.16%), 95.57% (95% CI: 95.20–95.94%), 83.56% (95% CI: 81.54–85.58%), and 69.12% (95% CI: 68.30–69.94%) respectively.ConclusionWe established four nomograms using easily accessible variables that could well predict the presence of MSI, CIMP, BRAF mutation and KRAS mutation in CRC patients.

Spatial heterogeneity of KRAS mutations in colorectal cancers: A population-based study in northern France.

e15101 Background: Somatic mutations in the KRAS gene are present in about 40% of tumors from colorectal cancer (CRC) patients and are associated with a resistance to anti-EGFR therapies. However, no clinical features have been linked to KRAS mutations in CRC. In this study, we attempted to identify the potential geographical population clusters of KRAS mutations in CRC patients in northern France. Methods: All patients with CRC who were identified to have KRAS mutations performed by pyrosequencing between 2008 and 2014 at the Regional Molecular Biology Platform at Lille University Hospital were included. We retrospectively collected demographic and geographic data from these patients. The proportions of KRAS mutation were smoothed to take into account the variability related to low frequencies and spatial autocorrelation. Geographical clusters were searched using spatial scan statistical models. Then, we made an ecological study. Results: 2,486 patients underwent a KRAS status available. A mutation of KRAS codon 12 or 13 performed by pyrosequencing was found in 1,018 patients (40.9%). We report 5 clusters of over-incidence but only one elongated cluster that was statistically significant ranging from the city of Tourcoing to the city of Marquion (Cluster 1; smoothed proportion of KRAS mutation: 0.4570; RR = 1.29; p = 0.0314). The ecological study did not highlight a significant association between KRAS mutations and the distance to the Closest Waste Incineration Plant , and between KRAS mutations and The French Ecological Deprivation Index. There was a greater frequency of KRAS mutations in some areas close to major highways and big cities in northern France. Conclusions: There is a spatial heterogeneity of KRAS codon 12 or 13 mutations in CRC in northern France. These data demand deeper epidemiological investigations to identify environmental factors such as air pollution as key factors in the occurrence of KRAS mutations.

Predictive value of 18F-FDG PET/CT related metabolic parameters for Kras mutation in colorectal cancer patients

Objective To explore the predictive value of 18F-fluorodeoxyglucose (FDG) PET/CT related metabolic parameters for Kras mutation in colorectal cancer (CRC) patients. Methods Retrospective analysis was conducted in 150 patients (105 males, 45 females, median age: 63 years) with CRC who underwent 18F-FDG PET/CT in Changhai Hospital of Navy Medical University between November 2011 and August 2017. The primary tumors were removed by surgery and patients received genetic testing within 1 month after PET/CT. 18F-FDG PET/CT related metabolic parameters were measured, including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV; including MTV2.5, MTV20%, MTV30%, MTV40%, MTV50%), total lesion glycolysis (TLG; including TLG2.5, TLG20%, TLG30%, TLG40%, TLG50%). Logistic regression analysis and receiver operating characteristic (ROC) curve analysis were used to analyze the data. Results There were 78 Kras-mutated type patients and 72 wild-type patients. Logistic regression analysis showed that SUVmax (odds ratio (OR)=1.176, 95% CI: 1.043-1.327) and MTV2.5 (OR=1.125, 95% CI: 1.002-1.263) were predictors of Kras mutation. With SUVmax=15.5 and MTV2.5=23.79 cm3 as the cut-off value, the prediction accuracies of Kras mutation were 67.33%(101/150) and 65.33%(98/150), respectively. The accuracies of SUVmax and MTV2.5 for predicting Kras mutation were higher in recta or sigmoid colon cancers (70.79%(63/89) and 68.54%(61/89)). Conclusion SUVmax and MTV2.5 can predict Kras mutation in CRC patients, but there is a significant gap of predictive efficiency between PET/CT and gene detection. Key words: Colorectal neoplasms; Oncogenes; Mutation; Positron-emission tomography; Deoxyglucose