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El estado mutacional del KRAS ha sido considerado como biomarcador para tratamientos biológicos tras varios ensayos clínicos realizados en pacientes con cáncer colorrectal metastásico. Reportes recientes indican que las frecuencias de mutación del gen KRAS en pacientes con CCR de Asia, Europa y Latinoamérica están entre el 24%, 36% y 40%, respectivamente. Paraguay no cuenta con este tipo de informes, a pesar de registrar anualmente en promedio 75 nuevos casos de pacientes diagnosticados con CCR sólo en el Servicio de Cirugía General del Hospital Central del Instituto de Previsión Social (IPS). El presente trabajo ha implementado este análisis de rutina, prerrequisito obligatorio para la administración de fármacos basados en anticuerpos terapéuticos, y revelado una frecuencia de mutación del gen KRAS del 34% en pacientes paraguayos con CCR que acuden a los Servicios del Hospital Central del IPS
The mutational status of the KRAS has been consider as a biomarker for biological treatments after several clinical trials carried out in patient with metastatic colorectal cancer. Recent reports indicate that the KRAS gene mutation frequencies in CRC patients from Asia, Europe, and Latin America are between 24%, 36%, and 40%, respectively. Paraguay does not have this kind of reports, despite registering an average of 75 new cases of patients diagnosed with CRC per year only in the General Surgery Service of the "Central Hospital - Instituto de Prevision Social (IPS)". The present work has implemented this routine analysis, a mandatory prerequisite for the administration of drugs based on therapeutic antibodies and revealed a KRAS gene mutation frequency of 34% in Paraguayan patients with CRC who attend the IPS Central Hospital Services
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Colorectal Neoplasms , Mutation , Cross-Sectional Studies , GenesABSTRACT
@# Objective： ：To detect the distribution of gene mutations in pancreatic mucinous cystadenocarcinoma (PMCC) by highthroughput sequencing and to explore its clinical significance. Methods: Four cases of paraffin-embedded cancer tissues and paracancerous tissues from PMCC patients, who underwent surgical resection from January 2012 to December 2016, received NGS (next generation sequencing) examination using Illumina Hiseq 2500 platform. The characteristics of gene mutation in PMCC patients were analyzed with sequencing results and clinicopathological data. Results: Seven significantly mutated genes (SMGs) were detected in all four PMCC samples, namely KRAS, AHNAK2, MUC16, MUC17, MUC19, MUC3A and MUC4. Twenty-four SMGs were detected in 3 of the 4 samples, namely ADAMTS9, ALDH3B1, CARD14, CSMD3, MKI67, OR1N2, PKHD1, PLCE1, RTL1, SIGLEC12, CCDC168, CEP295, CUBN, DST, HRNR, LAMA5, OR10G4, OR2T4, PLEKHG4B, RP1L1, SLC15A5, SVEP1, TAS1R1 and TNRC18. KRAS-driven gene mutations were detected in all 4 samples, including K12 hot spot mutation in 3 cases and D33E non-hot spot mutation in 1 case. Conclusion: The high mutation of KRAS and MUC family in PMCC may be a potential target and biomarker for precise treatment of PMCC.
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@# Objective: To investigate the correlation between KRAS gene mutation and differentiated thyroid carcinoma (DTC) treatment effect and prognosis, and to explore the mechanism. Methods: Clinical tissue samples from DTC patients undergoing 131I Radiotherapy were collected. Then single strand conformation polymorphism analysis of polymerase chain reaction products (PCRC-SSCP) was used to detect KRAS mutation rate in thyroid cancer patients of different TNM stages; p21 protein expression level was detected by real-time quantitative polymerase chain reaction (qPCR) and western blotting. DTC cells were treated by sub-lethal dose of 131I Radiotherapy, and then CCK-8 assay, transwell assay and flow cytometry (FCM) were used to evaluate the changes of cells viability. Animal models were then constructed for verification. Results: The results showed that KRAS gene mutants were increased in 131I-resistant DTC patients; KRAS gene mutation suppressed p21 protein expression and was associated with clinical stage and poor prognosis. In vivo and in vitro experiments proved that sub-lethal dose of 131I increased KRAS gene mutation rate, suppressed p21 expression level, and caused 131I radiotherapy resistance. Reversely, over-expression of KRAS gene could significantly increase p21 expression, and inhibit tumor proliferation and metastasis. Conclusion: KRAS gene mutations were associated with DTC TNM stages and 131I resistance in DTC patients. Sub-lethal dose of 131I treatment could improve 131I resistance in DTC cells line, inversely, over-expressed KRAS gene could increase the sensitivity to 131I radiotherapy in DTC patients.
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@# Objective: To explore the related factors for efficacy and prognosis of personalized comprehensive treatment for T790Mpositive lung adenocarcinoma patients with bone metastasis. Methods: The clinical data of 68 patients undergoing personalized comprehensive treatment for T790M-positive lung adenocarcinoma with bone metastasis were retrospectively reviewed; chemotherapy, radiotherapy, molecule-targeted agents, Bevacizumab, bisphosphonate and other therapies were chosen for the patients, and the efficacy and prognosis were observed to explore the related factors. Results: Effective rate of personalized comprehensive treatment was 60.3% (41/ 68), with a median survival time of 23 months. Multiple factors showed significant effects on long-term efficacy, such as no radiotherapy, T790M mutation but no KRAS mutation, adjuvant scheme+rescue scheme in prior chemotherapy treatment, N1 stage, isolated bone metastasis, alternative treatment of osimertinib with chemotherapy, less metastasized organs and ECOG scores<2 (P<0.05). Multivariate analysis revealed that T790M mutation but no KRAS mutation (P=0.012), number of metastasized organs =0 or 1 (P=0.000), alternative treatment of osimertinib with chemotherapy (P=0.020), and isolated bone metastasis (P=0.006) were independent protective factors for long-term results of personalized comprehensive treatment for T790M-positive lung adenocarcinoma patients with bone metastasis. Conclusion: Chemotherapy combined with osimertinib, agents of bisphosphonate and other personalized comprehensive treatment prolongs survival time in T790M-positive lung adenocarcinoma patients without KRAS mutation, providing a potential therapeutic model for those patients.
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Targeting KRAS mutations has always been a difficult issue in clinical tumor therapy as most tumors are accompanied by KRAS gene mutations, which indicate poor prognosis. The mutant KRAS protein is difficult to design specific inhibitors in the conventional way of inhibiting the active sites, which is known as "undmggble" target. Therefore, the exploration of drug strategies targeting KRAS mutations has become a hot spot in the research and development of antitumor drugs. Although the research progress of targeted KRAS treatment strategy is limited, some new strategies that directly or indirectly inhibit mutant KRAS are still emerging in view of the deepening understanding of KRAS mutation function and malignant mechanism. In this review, we discussed the research progress of targeted therapy for KRAS gene mutation in tumor, hoping to provide the latest clues for the treatment of KRAS mutant tumor.
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Objective To detect the frequency of BRAF/ KRAS and PIK3CA mutations in the small cell lung cancer (SCLC) specimens from a large population of Chinese patients and to analyze the gene mutation and clinical characteristics. Methods A total of 557 samples were collected from SCLC patients from 2009 to 2014.BRAF,KRAS,PIK3CA,NRAS and MEK1 gene mutations were detected by the dideoxy sequencing. Chi-square test was adopted to analyze the correlation between clinical factors and gene mutation. Kaplan-Meier method was utilized for survival analysis. Cox model was used for multivariate prognostic analysis. Results BRAF mutations were detected in 13 out of 557 specimens. The mutation types included V600E (n= 5) ,V600A (n= 2) ,V600M (n= 1) ,D594G (n= 1),G464E (n= 1),K601R (n= 2) and S605N (n= 1).KRAS mutation was detected in 6 cases including G12C (n= 3),G12A (n= 1),G12D (n=1) andG13D (n= 1).PIK3CA mutation was observed in 4 samples including E545G (n= 2) and H1047R (n= 2).Besides,NRAS mutation (Q61R) was detected in 1 case and MEK1 mutation (D61Y) was noted in 1 case. These gene mutations were not significantly correlated with the age, gender, smoking status and clinical staging of the patients. Univariate survival analysis demonstrated the median survival time of patients with gene mutation was (10.30±0. 751) months (95％CI:8. 829-11. 771 months),significantly shorter than (12.80±0. 543) months (95％CI:11. 736-13. 864 months) of their counterparts without gene mutation (P=0. 011). Conclusions BRAF/ KRAS and PIK3CA gene mutation is detected in a small proportion of SCLC patients. These gene mutations are not significantly correlated with the clinical characteristics. Univariate survival analysis demonstrates that negative these gene mutations are negatively correlated with the clinical prognosis of SCLC patients.
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Objective To establish a liquid biopsy technique of KRAS gene G12D mutation and to assess its diagnostic value. Methods KRAS G12D mutation was analyzed by ddPCR in plasma DNA from 52 colorectal cancer patients and compared that of to 80 healthy subjects. KRAS gene sequencing in cancerous tissue of colorectal cancer patient being set as a golden standard, we evaluated the accuracy of ddPCR and analyzed the correlation between G12D mutation rate, plasma concentration;and their clinical manifestations in CRC. Results ddPCR indicated that KRAS G12D mutation rate and concentration(26.92％, 81.5 copies/mL) in the plasma samples of colorectal cancer patients were significantly higher than that of healthy subjects (8.75％, 16 copies/mL). Colorectal cancer patients with highly differentiated adenocarcinoma showed a significantly higher number of mutant copies than medium and low differentiated adenocarcinoma(P＜0.05);M2 patients had a significantly higher number of mutant copies than N1 and NO patients (P＜0.05);The concordance rate of KRAS gene mutation between cancerous tissue and plasma ctDNA was 87.50％ in CRC.Conclusions ddPCR is a fast, noninvasive and accurate method for plasma testing of ctDNA, and the test results could be used to monitor the course of the disease and as clinical guidelines.
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Objective To explore the value of KRAS mutation predicting prognosis of patients with colorectal liver-only metastasis after hepatectomy.Methods The retrospective case-control study was conducted.The clinicopathological data of 79 patients with colorectal liver-only metastasis who underwent hepatectomy in the Sun Yat-sen University Cancer Center between October 2010 and October 2016 were collected.KRAS mutation in colorectal cancer tissue was detected by fluorescent quantitative polymerase chain reaction (PCR) and laser flight mass spectrometer.Observation indicators:(1) KRAS mutation;(2) relationship between KRAS mutation and clinicopathological factors of patients with colorectal liver-only metastasis;(3) follow-up and survival situations.Follow-up using outpatient examination and telephone interview was performed to detect recurrence-free survival and overall survival up to June 30,2017.The relationship between KRAS mutation and clinicopathological factors of patients with colorectal liver-only metastasis was analyzed by the chi-square test or Fisher exact probability.The survival curve and time were respectively drawn and calculated by the Kaplan-Meier method,and COX regression model was used for survival analysis.Results (1) KRAS mutation:79 patients received KRAS gene detection of surgical tumor tissues,including 54 in wide-type mutation and 25 in mutant-type mutation.Of 25 patients in mutant-type mutation,mutation at codon 12 of KRAS exon 2 was in 21 patients,and GGT＞GAT (G12D),GGT＞GTT (G12V),GGT＞TGT (G12C),GGT＞GCT (G12A) and GGT＞CGT (G12R) of mutation types were respectively detected in 13,4,2,1 and 1 patients;mutation at codon 13 of KRAS exon 2 was in 3 patients,with a mutation type of GGC＞GAC (G13D);mutation at codon 61 of KRAS exon 3 was in 1 patient,with a mutation type of CAA＞CAT (Q61H).(2) Relationship between KRAS mutation and clinicopathological factors of patients with colorectal liver-only metastasis:primary tumor located in right and left hemicolon were detected in 11,14 patients with mutant-type mutation and 7,47 patients with wide-type mutation,respectively,with a statistically significant difference (x2=9.357,P＜0.05).(3) Follow-up and survival situations:79 patients were followed up for 2.0-71.0 months,with a median time of 29.0 months.Median recurrence-free survival time and median overall survival time were respectively 11.3 months,43.5 months in patients with mutant-type mutation and 9.9 months,44.3 months in patients with wide-type mutation,respectively,with no statistically significant difference in recurrence-free and overall survivals [hazard ratio (HR)=1.255,1.108,95％ confidence interval (CI):0.741-2.126,0.521-2.355,P＞0.05].Further analysis:of patients with low clinical risk score (CRS) of Memorial Sloan Caitlin Cancer Center (MSKCC),median recurrence-free survival time was 11.3 months in 17 patients with mutant-type mutation and 23.5 months in 26 patients with wide-type mutation,with a statistically significant difference in recurrence-free survival of patients (HR=2.082,95％CI:1.006-4.307,P＜0.05).The median overall survival time was 44.6 months in 17 patients with mutant-type mutation and 49.0 months in 26 patients with wide-type mutation,with no statistically significant difference in overall survival of patients (HR =1.165,95％CI:0.413-3.282,P＞0.05).Of patients with high CRS of MSKCC,median recurrence-free survival time and median overall survival time were respectively 5.6 months,28.7 months in 7 patients with mutant-type mutation and 4.5 months,36.7 months in 24 patients with wide-type mutation,with no statistically significant difference in recurrence-free and overall survivals (HR=0.402,1.197,95％CI:0.284-1.656,0.371-3.866,P＞0.05).Conclusions KRAS mutation is often detected in patients with right colon cancer.Recurrence-free survival time is obviously reduced in patients with KRAS mutation and low CRS of MSKCC.
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Objective To investigate the association between KRAS gene mutations and clinicopathological characteristics and prognosis of colorectal cancer (CRC) patients.Methods The retrospective casecontrol study was conducted.The clinicophathological data of 315 patients who underwent radical resection of CRC in the Yangpu Hospital Affiliated to Tongji University between January 2007 and July 2011 were collected.Nextgeneration sequencing was performed to identify KRAS gene mutations from surgical specimens.Observation indicators:(1) detection of KRAS gene;(2) association between KRAS gene mutations and clinicopathological characteristics of CRC patients;(3) follow-up and survival situations;(4) multivariate analysis of KRAS gene mutations in the prognosis of CRC patients.Follow-up using outpatient examination and telephone interview was performed to detect postoperative overall survival up to August 2016.Comparisons of count data were analyzed using the chi-square test.Measurement data with skewed distribution were described as M (interquartile range),and comparison between groups was analyzed using the nonparametric test.The survival rate was calculated using the Kaplan-Meier method,and survival was compared using the Log-rank test.The multivariate analysis was done using the COX regression model.Results (1) Detection of KRAS gene:all the 315 patients finished gene detection of surgical specimens,including 172 in wide-type mutations and 143 in mutant-type mutations (mutations at codon 12 and 13 of KRAS exon 2 and other mutant points were respectively detected in 80,24 and 40 patients,and 1 patient had simultaneous mutations at codon 12 and 13 of KRAS exon 2;missense and nonsense mutations were respectively detected in 141 and 2 patients).The major point mutations were at p.G12D and p.G13D.(2) Association between KRAS gene mutations and clinicophathological characteristics of CRC patients:tumors located in the proximal colon,distal colon and rectum were respectively detected in 34,48,90 patients with wild-type mutation and in 44,27,72 patients with mutant-type mutation,with a statistically significant difference (x2 =0.038,P＜0.05).(3) Follow-up and survival situation:315 patients were followed up for 3-115 months,with a median time of 78 months.The postoperative overall survival rate was 41.0％ in 172 patients with wild-type KRAS mutations,27.4％ in 80 patients with KRAS codon 12 mutations,26.3％ in 24 patients with KRAS codon 13 mutations and 48.2％ in 40 patients with other KRAS mutations,showing a statistically significant difference (x2=0.040,P＜0.05).(4) Multivariate analysis of KRAS gene mutations in the prognosis of CRC patients:the results of multivariate analysis showed that mutations at codon 12 of KRAS exon 2 was an independent factor affecting poor prognosis of CRC patients (Hazard ratio=1.543,95％ confidence interval:1.050-2.265,P＜0.05).Conclusions Most KRAS mutations of CRC patients are at codon 12 and 13 of KRAS exon 2,and the major point mutations are at p.G12D and p.G13D.KRAS gene mutations may be associated with tumor location.Mutations at codon 12 of KRAS exon 2 is an independent factor affecting poor prognosis of CRC patients.
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Objective To investigate the effect of KRAS gene mutation and clinical factors on postopera-tive prognosis of rectal cancer patients and to explore their value in prognosis. Methods A total of 130 cases of rectal cancer patients from January to December 2010 were collected in the study. The tumor tissues sample was used to detect the KRAS gene mutation and 5-year follow-up was conducted. The correlation between KRAS gene mutation and clinical pathological features was analyzed.The clinic pathological factors that may affect the progno-sis were analyzed by survival analysis. Results Forty-five patients had mutations in No.2 expressed region of KRAS,with a mutation rate of 34.6%.KRAS gene mutation and stronger positive expression of EGFR(P<0.05), and multiple metastasis of tumor(P<0.05)were strongly coupled.The average survival of patients with wild-type KRAS gene was 57.5 months and that of patients with KRAS gene mutation 58.9 months but no significant differ-ence was observed(P>0.05).The TNM by high staging,multiple metastasis,lung metastasis and liver metasta-sis of cancer cells was closely related with poor postoperative prognosis of patients(P<0.05).The average surviv-al of postoperative patients in stage Ⅳ was 49months. Conclusions KRAS gene mutation in patients with rectal cancer after surgery is related with stronger positive expression of EGFR and multiple metastasis of cancer.TNM by high staging and metastatic sites affects the prognosis. The survival of rectal cancer after surgery in patients with stage Ⅳ are prolonged but the relation between KRAS genovariation and patients′ postoperative prognosis can not be determined.
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Objective To investigate the relationship between vessel cancer embolus with other clinicopathological features and tumor tissue KRAS gene mutation in the patients with colorectal cancer and its significance to colorectal cancer prognosis.Methods The postoperative clinicopathological data in 182 patients with colorectal cancer during 2011-2014 were retrospectively analyzed and the patients were followed up.Results Forty-five cases showed vessel cancer embolus positive of colorectal cancer,which had the rrelationship with the lymph node metastasis,pathological differentiation degree,liver metastasis,nerve infiltration and increase of CEA and CA199 levels,while had no relationship with the age,sex,tumor size,infiltration depth and pathological type.The 3-year survival rate was 51.1% in the vessel cancer embolus positive group,which was significantly lower than 61.3% in the negative group (P0.05).Conclusion Vessel cancer embolus decreases the 3-year survival rate and affects the prognosis in the patients with colorectal cancer.The survival rate in complicating KRAS gene mutation is similar.
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Objective:To investigate the relationship between primary resection and KRAS gene mutation in the mild symptomatic patients with stage Ⅳ colorectal cancer,and to clarify its significance of prognosis.Methods:The clinical data of 46 mild symptomatic patients with stage Ⅳ colorectal cancer 2010 to December 2010 were collected.All the patients received primary resection.The KRAS gene mutation in the patients was detected by direct sequencing and the patients were followed up for 5 years.The influence of primary resection and KRAS gene mutation in prognosis of the patients with stage Ⅳ colorectal cancer was analyzed, and the clinical pathological features which might influence the prognosis were analyzed by survival analysis.Results:In 46 patients with colorectal cancer, KRAS gene mutation was found in 20 cases, the mutation rate was 43.4%, and most mutation was found at Codon 12. The KRAS mutation had relationship with the tumor site and multiple metastasis (P0.05).The median survival time of right colon cancer patients was 34.2 months, the median survival time of left colon cancer patients was 58.3 months, and there was sigificant difference (P<0.05).The cancer metastases including liver, lung and multiple metastasis were closely related to the poor prognosis of the colorectal cancer patients(P<0.05).The median survival time of the patients with stage Ⅳ colorectal cancer was 39.6 months after operation.Conclusion:After primary resection of the mild symptomatic patients with stage Ⅳ colorectal cancer,the median survival time of the patients with colorectal cancer in left colon site and right colon site were prolonged.Right colon cancer has more poorer prognosis than left colon cancer.KRAS gene mutation is associated with the tumor site and the multiple metastasis.The location of metastasis affect the prognosis.
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Objective:To investigate the KRAS gene mutation features in lung and gastric cancers and their relationship with clinicopathologic characteristics. Methods:A total of 128 lung cancer and 115 gastric cancer patients were included. Polymerase chain reaction amplification and DNA sequencing were conducted to detect mutations in exon 2 of the KRAS gene. Results:The mutation frequency of KRAS was different in lung and gastric cancers;however, it did not show any statistical significance (6.3%vs. 4.3%, P>0.05). The KRAS codon 12 gene mutation ranks the first in both types of cancer. No significant correlation was observed between the prevalence of KRAS mutations and patient's age and gender. KRAS gene mutation rate was higher in lung adenocarcinoma than in non-adenocarcinoma, such as squamous cancer (10.7%vs. 0%, P<0.05). Conclusion:No correlation was found between the KRAS gene mutation and the sex and age of lung and gastric cancer patients in Jiangsu Province. The rate of KRAS mutation was low. KRAS gene mutation rate was relatively higher in lung adenocarcinoma patients;thus, the mutation status of the KRAS gene should be evaluated be-fore undergoing EGFR-TKI therapy.
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Personalized targeted therapy in addition to standard chemotherapy has become a hot topic in the treatment of metastatic colorectal cancer (mCRC). KRAS gene mutation has been considered as a predictor for poor response to anti-epidermal growth factor receptor monoclonal antibody (anti-EGFR) therapy in patients with mCRC. The percentage of KRAS mutation is 35%-45% in patients with mCRC, and these patients have poor response to anti-EGFR; while only 50% of patients with wild-type KRAS respond to anti-EGFR, which suggests that the activation and variation of other molecules in the downstream of EGFR signaling pathway can influence the therapeutic effects. The two major EGFR-dependent signaling pathways - RAS-RAF-MAPK and PI3K-PTEN-AKT may be involved in poor response to anti-EGFR in the treatment of mCRC. In addition, the increased EGFR gene copy number (GCN) is associated with the efficacy of anti-EGFR therapy, but not associated with the expression level of EGFR protein which has no correlation with the efficacy of anti-EGFR therapy. Additional detection of mutations in BRAF and PIK3CA genes as well as deletion of PTEN gene in wild-type KRAS patients with mCRC may be helpful in further selection of patients with anti-EGFR resistance. This paper reviews recent progress on molecular markers associated with treatment outcome and prognosis predictions in the treatment of mCRC, in order to guide individualized molecular targeted therapy for mCRC. Copyright© 2011 by TUMOR.
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ObjectiveTo evaluate the feasibility of detecting the mutations of KRAS,EGFR in nonsmall-cell lung cancer and colorectal cancer patients with high resolution melting curve analysis. MethodsAt first,the mutations in KRAS exon 2 and EGFR exons 18 to 21 of 5 patients with non-small cell lung cancer and 5 patients with colorectal cancer were detected by high resolution melting curve analysis.Then the results were confirmed with direct sequencing. ResultsBy high resolution melting curve analysis,1 of 10 patients was found to carry EGFR 19 mutation who was harboring 2236-2250del mutation.By direct sequencing,consistent results of the patients with mutations orwithout mutations were got. Conclusion s The new high resolution melting curve analysis was more efficient,more convenient than direct sequencing.Moreover,it was a low-cost test,which was suitable for clinic test.
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Noonan syndrome is an autosomal dominant disorder characterized by typical facial features, congenital heart disease, and short stature. Diagnosis is difficult only with clinical symptoms and it is recently confirmed with gene study. The genotype-phenotype correlations have been reported. We report a newborn with KRAS gene mutation. This is the second report of case with KRAS gene mutation in Korea. So we hope this case will be a help to diagnosis and treatment of Noonan syndrome from birth.
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Humans , Infant, Newborn , Genetic Association Studies , Heart Diseases , Korea , Noonan Syndrome , ParturitionABSTRACT
BACKGROUND: Rapid and sensitive detection of KRAS mutation is needed to maximize the benefits for patients who are being treated with monoclonal antibodies to target the epidermal growth factor receptor in colorectal cancer. The aim of this study is to evaluate the efficacy of the peptide nucleic acid clamp real-time PCR (PCqPCR) as compared to that of direct sequencing (DS) between using fresh colorectal cancer tissue and the matched formalin-fixed and paraffin-embedded (FFPE) colorectal cancer tissue. METHODS: The efficacy of PCqPCR was evaluated and compared with that of DS using fresh tissue and matched FFPE tissue from 30 cases of colorectal cancer. RESULTS: PCqPCR is more sensitive than DS for detecting KRAS mutation. PCqPCR detected 1% of mutants in 1 ng DNA. PCqPCR detected mutation in 1% of mutant cells, while DS barely detected, by manual reading, that in 20-50% of mutant cells. In the clinical samples, PCqPCR detected KRAS mutation in 60.0% while DS detected KRAS mutation in 53.3% of the colorectal cancers. The two methods showed a 100% concordance rate for detecting KRAS mutation between the fresh tissue and FFPE tissue. CONCLUSIONS: The PCqPCR method is efficiently applicable for the detection of KRAS mutation in a clinical setting.