Detection of KRAS Gene mutations in paraguayan patients with colorectal cancer

KRAS, NRAS, BRAF mutations are associated with an unfavorable prognosis for colorectal cancer (CRC). At the same time, there is no single point of view on disease development during adjuvant chemotherapy (ACT). Objective. The authors aimed at studying KRAS, NRAS and BRAF mutations in the tumor and their influence on the clinical characteristics of colorectal cancer development. Materials and Methods. Paraffin blocks of the primary CRC tumor (n=37) were used as the material for the study. Using genomic DNA, isolated from the primary tumor, real-time PCR was used to determine the most common mutations in CRC: KRAS gene (exon 2, codon region 12–13), NRAS gene (exon 3, codon region 61), B6F V600E gene. Results. The results of genotyping of DNA samples isolated from the primary CRC tumor paraffin blocks showed that BRAF gene mutations were detected in 8.2 % of cases, NRAS gene mutations were detected in 5.4 % of cases, and KRAS gene mutations were detected in 37.8 % of cases. The authors didn’t reveal any dependencies of the mutation distribution on patients’ gender and age. The examined mutations were more common in adenocarcinomas of high and moderate degrees of differentiation. The relapse-free period after ACT in patients with identified KRAS, NRAS, BRAF gene mutations is significantly less than in those without mutations. Conclusion. The findings suggest that EGFR signaling pathway mutations (KRAS, NRAS and BRAF) increase the risk of disease recurrence and are an unfavorable prognostic factor. Keywords: colorectal cancer, NRAS, KRAS, BRAF mutations, adjuvant chemotherapy.

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KRAS mutation is highly predictive of cetuximab resistance in metastatic colorectal cancer

Journal of Clinical Oncology ◽

10.1200/jco.2007.25.18_suppl.10502 ◽

2007 ◽

Vol 25 (18_suppl) ◽

pp. 10502-10502 ◽

Cited By ~ 7

Author(s):

F. Di Fiore ◽

F. Le Pessot ◽

A. Lamy ◽

F. Charbonnier ◽

J. Sabourin ◽

...

Keyword(s):

Colorectal Cancer ◽

Metastatic Colorectal Cancer ◽

Predictive Factors ◽

Kras Mutation ◽

Copy Number ◽

Gene Copy Number ◽

Gene Mutations ◽

Gene Copy ◽

Kras Gene ◽

Egfr Gene

10502 Background: In metastatic colorectal cancer (MCRC), no molecular predictive markers to cetuximab response have been yet established. The aim was to evaluate whether KRAS gene mutations, EGFR immunochemistery (IHC) and EGFR gene copy number correlate with response to cetuximab. Methods: 59 patients with MCRC treated by cetuximab between July 2004 and December 2005 were retrospectively included. Clinical data were collected and tumour response was evaluated according to RECIST criteria. EGFR IHC was performed using the Dako kit. The EGFR gene copy number was determined by FISH (Fluorescence in-Situ Hybridization). Detection of KRAS gene mutations on exon 2 was performed by sequencing of extracted paraffin-embedded DNA and then by 2 methods, SNaPshot and PCR-LCR, specifically developed to detect small fractions of mutated tumor cells. Response to cetuximab was studied according to clinical data, IHC, FISH and KRAS mutation analysis using the Fischer exact test. Predictive factors of response were determined by logistic regression. Skin reactions were collected but not considered for this analysis as regards the lack of accurate grading in a retrospective study. Times to progression (TTP) were calculated using the Kaplan-Meier method and compared with log-rank test. Results: 12 patients (20.3%) responded to cetuximab (2 patients with complete response and 10 patients with partial response), 19 (32.2%) had stable disease and 28 (47.5%) were in disease progression. A KRAS mutation was detected in 22/59 tumours and, in 6 cases, was missed by sequencing analysis but detected using the SNaPshot and PCR-LCR assays. No KRAS mutation was found in responders patients. KRAS mutation was associated with disease progression (p = 0.0005) and TTP was significantly decreased in mutated KRAS patients (3 vs 5.5 months, p = 0.015). There was no correlation between EGFR IHC and cetuximab response. No EGFR gene copy number increase was detected in responders patients. Predictive factors of cetuximab resistance were KRAS mutation (p=0.003; OR:0.10; 95IC:0.22–0.40) and age<60 (p=0.024; OR:0.13; 95IC:0.02–0.77). Conclusions: KRAS mutation is highly predictive of cetuximab resistance in MCRC. Our study also highlights the need of sensitive methods to ensure an efficient mutation detection. No significant financial relationships to disclose.

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1322 Diagnostic of KRAS gene mutations in colorectal cancer: evaluation of direct sequencing, pyrosequencing and allele specific amplification

European Journal of Cancer Supplements ◽

10.1016/s1359-6349(09)70495-1 ◽

2009 ◽

Vol 7 (2) ◽

pp. 145 ◽

Cited By ~ 1

Author(s):

P.J. Lamy ◽

F. Montels ◽

A.C. Servanton ◽

M. Ychou ◽

E. Crapez

Keyword(s):

Colorectal Cancer ◽

Direct Sequencing ◽

Gene Mutations ◽

Kras Gene ◽

Allele Specific ◽

Specific Amplification

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3014 (Presidential session, Tue 25 Sep 12.30–14.30) ORAL Association of somatic KRAS gene mutations and clinical outcome in patients (pts) with metastatic colorectal cancer (mCRC) receiving panitumumab monotherapy

European Journal of Cancer Supplements ◽

10.1016/s1359-6349(07)70942-4 ◽

2007 ◽

Vol 5 (4) ◽

pp. 239 ◽

Cited By ~ 11

Author(s):

D. Freeman ◽

T. Juan ◽

N.J. Meropol ◽

J.R. Hecht ◽

J. Berlin ◽

...

Keyword(s):

Colorectal Cancer ◽

Clinical Outcome ◽

Metastatic Colorectal Cancer ◽

Gene Mutations ◽

Kras Gene ◽

Presidential Session

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KRAS Gene Mutations and Gender Differences in Colorectal Cancer

International Journal of Biomedicine ◽

10.21103/article5(1)_cr2 ◽

2015 ◽

Vol 5 (1) ◽

pp. 11-15 ◽

Cited By ~ 1

Author(s):

Oleg Kit ◽

◽

Dmitriy Vodolazhskiy ◽

Yuriy Gevorkyan ◽

Natalia Soldatkina ◽

...

Keyword(s):

Colorectal Cancer ◽

Gender Differences ◽

Gene Mutations ◽

Kras Gene ◽

And Gender

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A Cross-Sectional Study for Evaluation of KRAS and BRAF Mutations by Reverse Dot Blot, PCR-RFLP, and Allele-Specific PCR Methods Among Patients with Colorectal Cancer

Avicenna Journal of Medical Biotechnology ◽

10.18502/ajmb.v13i4.7203 ◽

2021 ◽

Author(s):

Fatemeh Sheikhsofla ◽

Behzad Poopak ◽

Sajjad Firuzyar ◽

Fatemeh Roudbari ◽

Mojtaba Ghadiany

Keyword(s):

Colorectal Cancer ◽

Gene Mutations ◽

Dot Blot ◽

Braf Mutations ◽

Kras Gene ◽

Specific Pcr ◽

Pcr Rflp ◽

Allele Specific ◽

Allele Specific Pcr ◽

Reverse Dot Blot

Background: KRAS and BRAF genes are the biomarkers in Colorectal Cancer (CRC) which play prognostic and predictive roles in CRC treatment. Nowadays, the selection of rapid and available methods for studying KRAS and BRAF mutations in anti-EGFR therapy of patients suffering from CRC plays a significant role. In this study, the mutations of these two oncogenes were evaluated by different methods. Methods: This study was performed on 50 Formalin-Fixed Paraffin-Embedded (FFPE) tissue blocks of patients diagnosed with colorectal cancer. After DNA extraction, KRAS and BRAF gene mutations were evaluated using reverse dot blot, and results were compared with PCR-RFLP and allele-specific PCR for KRAS and BRAF mutations, respectively. Results: KRAS gene mutations were detected in 42% of patients, of which 30% were in codon 12 region, and 12% in codon 13. The most frequent mutations of KRAS were related to G12D and 10% of patients had BRAF mutated genes. The type of KRAS gene mutations could be evaluated by reverse dot blot method. In general, the results of PCR-RFLP and allele-specific PCR were similar to the findings by reverse dot blot method. Conclusion: These findings suggest that PCR-RFLP and allele-specific PCR methods are suitable for screening the presence of the mutations in KRAS and BRAF oncogenes. In fact, another method with more sensitivity is needed for a more accurate assessment to determine the type of mutations. Due to higher speed of detection, reduced Turnaround Time (TAT), and possible role of some KRAS point mutations in overall survival, reverse dot blot analysis seems to be an optimal method.

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

BMC Cancer ◽

10.1186/s12885-020-07551-4 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Yinghao Cao ◽

Junnan Gu ◽

Lizhao Yan ◽

Shenghe Deng ◽

Fuwei Mao ◽

...

Keyword(s):

Colorectal Cancer ◽

Logistic Regression ◽

Predictive Value ◽

Gene Mutations ◽

Haematological Parameters ◽

Multivariate Logistic Regression ◽

Kras Gene ◽

Kras Mutations ◽

Mutation Status ◽

Serum Tumour

Abstract Background Identifying 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. Methods The 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). Results KRAS 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). Conclusions Haematological 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.

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