KRAS, BRAF, PIK3CA, and PTEN mutations: implications for targeted therapies in metastatic colorectal cancer

The discovery of mutant KRAS as a predictor of resistance to epidermal growth-factor receptor (EGFR) monoclonal antibodies brought a major change in the treatment of metastatic colorectal cancer. This seminal finding also highlighted our sparse knowledge about key signalling pathways in colorectal tumours. Drugs that inhibit oncogenic alterations such as phospho-MAP2K (also called MEK), phospho-AKT, and mutant B-RAF seem promising as single treatment or when given with EGFR inhibitors. However, our understanding of the precise role these potential drug targets have in colorectal tumours, and the oncogenic dependence that tumours might have on these components, has not progressed at the same rate. As a result, patient selection and prediction of treatment effects remain problematic. We review the role of mutations in genes other than KRAS on the efficacy of anti-EGFR therapy, and discuss strategies to target these oncogenic alterations alone or in combination with receptor tyrosine-kinase inhibition.     

The prognostic role of KRAS,BRAF, PIK3CA and PTEN in colorectal cancer

Background

Mutations in KRAS, BRAF, PIK3CA and PTEN expression have been in focus to predict the effect of epidermal growth factor receptor-blocking therapy in colorectal cancer (CRC). Here, information on these four aberrations was collected and combined to a Quadruple index and used to evaluate the prognostic role of these factors in CRC.

Patients

We analysed the mutation status in KRAS, BRAF and PIK3CA and PTEN expression in two separate CRC cohorts, Northern Sweden Health Disease Study (NSHDS; n=197) and Colorectal Cancer in Umeå Study (CRUMS; n=414). A Quadruple index was created, where Quadruple index positivity specifies cases with any aberration in KRAS, BRAF, PIK3CA or PTEN expression.

Results

Quadruple index positive tumours had a worse prognosis, significant in the NSHDS but not in the CRUMS cohort (NSHDS; P=0.003 and CRUMS; P=0.230) in univariate analyses but significance was lost in multivariate analyses. When analysing each gene separately, only BRAF was of prognostic significance in the NSHDS cohort (multivariate HR 2.00, 95% CI: 1.16–3.43) and KRAS was of prognostic significance in the CRUMS cohort (multivariate HR 1.48, 95% CI: 1.02–2.16). Aberrations in PIK3CA and PTEN did not add significant prognostic information.

Conclusions

Our results suggest that establishment of molecular subgroups based on KRAS and BRAF mutation status is important and should be considered in future prognostic studies in CRC.     

Heterogeneity of KRAS,NRAS, BRAF and PIK3CA mutations in metastatic colorectal cancer and potential effects on therapy in the CAPRI GOIM trial

BackgroundEvidence suggests that metastatic colorectal carcinoma (mCRC) has a high level of intratumor heterogeneity. We carried out a quantitative assessment of tumor heterogeneity for KRAS, NRAS, BRAF and PIK3CA mutations, in order to assess potential clinical implications.Patients and methodsTumor samples (n = 182) from the CAPRI-GOIM trial of first-line cetuximab + FOLFIRI in KRAS exon-2 wild-type mCRC patients were assessed by next-generation sequencing that allows quantitative assessment of mutant genes. Mutant allelic frequency was normalized for the neoplastic cell content and, assuming that somatic mutations usually affect one allele, the Heterogeneity Score (HS) was calculated by multiplying by 2 the frequency of mutant alleles in neoplastic cells. Therefore, HS virtually corresponds to the fraction of neoplastic cells carrying a specific mutation.ResultsThe KRAS HS ranged between 12 and 260 with mean value of 87.1 and median value of 84.4, suggesting that in most CRC, the majority of neoplastic cells carry mutant KRAS. Similar findings were observed for NRAS (HS range 35.5–146.7; mean 102.8; median 117.1). In contrast, in BRAF (HS range 17.1–120; mean 54.8; median 54.3) and PIK3CA (HS range 14.3–120; mean 59.5; median 47.3) mutant cases, only a fraction of neoplastic cells seem to carry the mutant allele. The response rate was 70% in KRAS mutant patients with an HS <33 (low KRAS; n = 10) and 45.7% in KRAS HS >33 patients (high KRAS; n = 35); median progression-free survival were 7.97 and 8.37 months, respectively. Low-KRAS tumors had a higher frequency of additional mutations in PIK3CA when compared with high-KRAS (6/10 versus 8/35).ConclusionsKRAS and NRAS mutations are usually present in the majority of neoplastic cells, whereas BRAF and PIK3CA mutations often affect a limited fraction of transformed cells. Resistance to cetuximab in low-KRAS patients might be driven by the complex mutational profile rather than KRAS mutation load.     

Clinical usefulness of KRAS, BRAF, and PIK3CA mutations as predictive markers of cetuximab efficacy in irinotecan- and oxaliplatin-refractory Japanese patients with metastatic colorectal cancer

Background

Anti-epidermal growth factor receptor (EGFR) antibodies, cetuximab, and panitumumab are established as a new treatment option for metastatic colorectal cancer (mCRC). Among activating mutations downstream of EGFR, the KRAS mutation, which is present in 30–45 % of CRC patients, has shown to be a predictive biomarker of resistance to anti-EGFR antibody therapy based on Caucasian studies.

Methods

Forty-three chemotherapy-refractory Japanese patients with mCRC were treated with cetuximab monotherapy or cetuximab plus irinotecan. KRAS, BRAF, and PIK3CA mutational status of tumors was assessed. The association between mutational status and treatment outcome was evaluated.

Results

Of 43 tumors, KRAS, BRAF, and PIK3CA mutations were identified in 12 (27.9 %), 2 (4.7 %), and 2 (4.7 %) tumors, respectively. The wild-type KRAS subgroup showed better clinical outcomes than the mutant KRAS subgroup in terms of response rate (RR) (31.3 % vs. 0 %, P = 0.034) and progression-free survival (PFS) (5.1 vs. 3.0 months, P = 0.017). No responder to treatment was shown in 16 (37.2 %) patients with tumors harboring mutations in any one of the three genes (KRAS, BRAF, and PIK3CA). The wild-type subgroup without any mutations in KRAS, BRAF, and PIK3CA had a better RR (37.0 %) and PFS (6.4 months) than did the wild-type KRAS subgroup.

Conclusion

Our data indicated that KRAS status is predictive of cetuximab response in the Japanese population. The additional analysis of BRAF and PIK3CA genes in wild-type KRAS patients could improve selection of patients who are most likely to benefit from anti-EGFR antibody therapy.     

Functional analysis of PIK3CA gene mutations in human colorectal cancer

Mutations in the PIK3CA gene, which encodes the p110alpha catalytic subunit of phosphatidylinositol 3-kinase (PI3K), have been reported in human cancers, including colorectal cancer. Most of the mutations cluster at hotspots within the helical and kinase domains. Whereas H1047R, one of the hotspot mutants, is reported to have elevated lipid kinase activity, the functional consequences of other mutations have not been examined. In this study, we examined the effects of colon cancer-associated PIK3CA mutations on the lipid kinase activity in vitro, activation of the downstream targets Akt and p70S6K in vivo and NIH 3T3-transforming ability. Of eight mutations examined, all showed increased lipid kinase activity compared with wild-type p110alpha. All the mutants strongly activated Akt and p70S6K compared with wild-type p110alpha as determined by immunoblotting using phospho-specific antibodies. These mutants also induced morphologic changes, loss of contact inhibition, and anchorage-independent growth of NIH 3T3 cells. The hotspot mutations examined in this study, E542K, E545K, and H1047R, all had high enzymatic and transforming activities. These results show that almost all the colon cancer-associated PIK3CA mutations are functionally active so that they are likely to be involved in carcinogenesis.     

KRAS,NRAS and BRAF mutations in colorectal cancer and melanoma

Cancers are the group of diseases, which arise because of the uncontrolled behavior of some of the genes in our cells. There are possibilities of gene amplifications, overexpressions, deletions and other anomalies which might lead to the development and spread of cancer. One of the most dangerous ways to the cancers is the mutations of the genes. The mutated genes can start unstoppable proliferation of cells, their uncontrolled motility, protection from apoptosis, the DNA mutation enhancement as well as other anomalies, leading to the cancer. This review focuses on the genes, which are frequently mutated in various cancers and are known to be important in the advance and progression of colorectal cancer and melanoma, namely KRAS, NRAS and BRAF.     

中国人群结直肠癌中PIK3CA基因突变分析

目的:PIK3CA基因编码ⅠA型磷脂酰肌醇-3-激酶(PI3Ks)的p110催化亚基,致癌性的PIK3CA突变可通过激活P13K通路参与结直肠癌的发生发展。PIK3CA在西方结直肠癌患者中有较高的突变频率,但其在中国人结直肠癌中的突变情况尚不明确。本研究旨在探讨中国人结直肠癌中PIK3CA基因的突变频率、分布特点及其与结直肠癌的关系。方法:采用PCR产物直接测序法,对79例中国结直肠癌患者肿瘤标本中PIK3CA基因外显子9和外显子20中的突变进行检测分析。结果:在79例肿瘤标本中检出PIK3CA基因突变率为8.9%(7/79),其中外显子9突变率为6.3%(5/79),外显子20突变率为2.5%(2/79),其突变热点分布与既往文献报道基本相符。结论:中国人结直肠癌中存在一个PIK3CA基因突变的亚群,其E542K、E545K和H1047R突变,与以往报道的该基因的致癌性突变相一致,可能是这部分结直肠癌中PI3K信号通路激活的原因。     

Phase II study of high-sensitivity genotyping of KRAS,NRAS, BRAF and PIK3CA to ultra-select metastatic colorectal cancer patients for panitumumab plus FOLFIRI: the ULTRA trial

BackgroundSeveral studies show the importance of accurately quantifying not only KRAS and other low-abundant mutations because benefits of anti-EGFR therapies may depend on certain sensitivity thresholds. We assessed whether ultra-selection of patients using a high-sensitive digital PCR (dPCR) to determine KRAS, NRAS, BRAF and PIK3CA status can improve clinical outcomes of panitumumab plus FOLFIRI.Patients and methodsThis was a single-arm phase II trial that analysed 38 KRAS, NRAS, BRAF and PIK3CA hotspots in tumour tissues of irinotecan-resistant metastatic colorectal cancer patients who received panitumumab plus FOLFIRI until disease progression or early withdrawal. Mutation profiles were identified by nanofluidic dPCR and correlated with clinical outcomes (ORR, overall response rate; PFS, progression-free survival; OS, overall survival) using cut-offs from 0% to 5%. A quantitative PCR (qPCR) analysis was also performed.ResultsSeventy-two evaluable patients were enrolled. RAS (KRAS/NRAS) mutations were detected in 23 (32%) patients and RAS/BRAF mutations in 25 (35%) by dPCR, while they were detected in 7 (10%) and 11 (15%) patients, respectively, by qPCR. PIK3CA mutations were not considered in the analyses as they were only detected in 2 (3%) patients by dPCR and in 1 (1%) patient by qPCR. The use of different dPCR cut-offs for RAS (KRAS/NRAS) and RAS/BRAF analyses translated into differential clinical outcomes. The highest ORR, PFS and OS in wild-type patients with their lowest values in patients with mutations were achieved with a 5% cut-off. We observed similar outcomes in RAS/BRAF wild-type and mutant patients defined by qPCR.ConclusionsHigh-sensitive dPCR accurately identified patients with KRAS, NRAS, BRAF and PIK3CA mutations. The optimal RAS/BRAF mutational cut-off for outcome prediction is 5%, which explains that the predictive performance of qPCR was not improved by dPCR. The biological and clinical implications of low-frequent mutated alleles warrant further investigations.ClinicalTrials.gov numberNCT01704703.EudraCT number2012-001955-38.     

Coexistence of EGFR with KRAS,or BRAF,or PIK3CA somatic mutations in lung cancer: a comprehensive mutation profiling from 5125 Chinese cohorts

Background:

Determining the somatic mutations of epidermal growth factor receptor (EGFR)-pathway networks is the key to effective treatment for non-small cell lung cancer (NSCLC) with tyrosine kinase inhibitors (TKIs).The somatic mutation frequencies and their association with gender, smoking history and histology was analysed and reported in this study.

Methods:

Five thousand one hundred and twenty-five NSCLC patients'' pathology samples were collected, and EGFR, KRAS, BRAF and PIK3CA mutations were detected by multiplex testing. The mutation status of EGFR, KRAS, BRAF and PIK3CA and their association with gender, age, smoking history and histological type were evaluated by appropriate statistical analysis.

Results:

EGFR, KRAS, BRAF and PIK3CA mutation rates revealed 36.2%, 8.4%, 0.5% and 3.3%, respectively, across the 5125 pathology samples. For the first time, evidence of KRAS mutations were detected in two female, non-smoking patients, age 5 and 14, with NSCLC. Furthermore, we identified 153 double and coexisting mutations and 7 triple mutations. Interestingly, the second drug-resistant mutations, T790M or E545K, were found in 44 samples from patients who had never received TKI treatments.

Conclusions:

EGFR exons 19, 20 and 21, and BRAF mutations tend to happen in females and non-smokers, whereas KRAS mutations were more inclined to males and smokers. Activating and resistant mutations to EGFR-TKI drugs can coexist and ‘second drug-resistant mutations'', T790M or E545K, may be primary mutations in some patients. These results will help oncologists to decide candidates for mutation testing and EGFR-TKI treatment.     

结直肠癌Ras、BRAF和PIK3CA基因突变分析及与临床病理特征的关系

目的 分析结直肠癌患者中Ras（K-Ras／N-Ras）、BRAF和PIK3CA基因突变情况及其与临床病理特征的关系。方法 回顾性分析2013年12月至2014年10月于北京大学肿瘤医院消化肿瘤内科接受诊治的200例结直肠癌患者的肿瘤组织标本,采用PCR扩增-直接测序法检测Ras,包括K-Ras（第2、3、4外显子）、N-Ras（第2、3、4外显子）、BRAF（第15外显子）及PIK3CA（第9、20外显子）基因的突变状态,分析其与结直肠癌临床病理特征的关系。结果 200例患者中存在Ras基因突变92例（46.0％）,其中K-Ras基因突变87例（43.5％）,主要发生在外显子2,N-Ras基因突变5例（2.5％）;其中1例患者存在K-Ras、N-Ras基因同时突变。存在BRAF基因突变15例（7.5％）,突变类型均为V600E,且与K-Ras突变存在排他性。存在PIK3CA基因突变9例（4.5％）,可与Ras或BRAF基因突变共存。Ras（K-Ras／N-Ras）基因在年龄≥65岁患者中的突变率明显高于＜65岁者（P＜0.05）,其表达与性别、原发部位、组织学类型、分化程度、TNM分期、区域淋巴结转移、远处转移、术后复发转移均无关（P均＞0.05）。BRAF、PIK3CA基因在原发部位为右半结肠患者中的突变率明显升高（P＜0.05）,但与年龄、性别、组织学类型、分化程度、TNM分期、区域淋巴结转移、远处转移、术后复发转移均无关（P＞0.05）。结论 N-Ras、PIK3CA基因在中国结直肠癌患者中的突变率较低。K-Ras、N-Ras基因突变与年龄相关,BRAF、PIK3CA基因与肿瘤原发部位相关;对结直肠癌患者进行Ras（K-Ras／N-Ras）、BRAF及PIK3CA基因的联合检测将会为提高临床靶向治疗的疗效提供更加可靠的依据。     

Molecular spectrum of KRAS,BRAF, and PIK3CA gene mutation: determination of frequency,distribution pattern in Indian colorectal carcinoma

Molecular evaluation of KRAS, BRAF, and PIK3CA mutation has become an important part in colorectal carcinoma evaluation, and their alterations may determine the therapeutic response to anti-EGFR therapy. The current study demonstrates the evaluation of KRAS, BRAF, and PIK3CA mutation using direct sequencing in 204 samples. The frequency of KRAS, BRAF, and PIK3CA mutations was 23.5, 9.8, and 5.9 %, respectively. Five different substitution mutations at KRAS codon 12 (G12S, G12D, G12A, G12V, and G12C) and one substitution type at codon 13 (G13D) were observed. KRAS mutations were significantly higher in patients who were >50 years, and were associated with moderate/poorly differentiated tumors and adenocarcinomas. All mutations in BRAF gene were of V600E type, which were frequent in patients who were ≤50 years. Unlike KRAS mutations, BRAF mutations were more frequent in well-differentiated tumors and right-sided tumors. PIK3CA–E545K was the most recurrent mutation while other mutations detected were T544I, Q546R, H1047R, G1049S, and D1056N. No significant association of PIK3CA mutation with age, tumor differentiation, location, and other parameters was noted. No concomitant mutation of KRAS and BRAF mutations was observed, while, interestingly, five cases showed concurrent mutation of KRAS and PIK3CA mutations. In conclusion, to our knowledge, this is the first study to evaluate the PIK3CA mutation in Indian CRC patients. The frequency of KRAS, BRAF, and PIK3CA was similar to worldwide reports. Furthermore, identification of molecular markers has unique strengths, and can provide insights into the pathogenic process and help optimize personalized prevention and therapy.     

Prognostic relevance of KRAS and BRAF mutations in Japanese patients with colorectal cancer

Background

Mutations of the KRAS or BRAF genes are now recognized as prognostic markers for colorectal cancer (CRC). They are also important predictive markers for resistance to the monoclonal antibodies that target the epidermal growth factor receptor.

Methods

In this retrospective study, KRAS and BRAF mutations were analyzed using a direct sequence method in 254 Japanese CRC patients, and the associations between KRAS or BRAF mutations and clinicopathological characteristics or outcome were evaluated.

Results

KRAS and BRAF mutations were detected in 33.5 and 6.7 % of all patients, respectively. Consistent with previous reports, BRAF mutations were significantly correlated with the anatomical site of the tumor (P < 0.001), tumor grade (P = 0.001) and high frequency of microsatellite instability (P < 0.001). BRAF mutations were correlated with poor overall survival in the full patient cohort (P = 0.009). KRAS mutations were significantly correlated with poor recurrence-free survival (P = 0.03), particularly in patients with stage II CRC (P = 0.007). Cox regression analysis showed that KRAS mutations were a negative predictor of recurrence-free survival in patients with stage II CRC.

Conclusion

KRAS mutation status could be a novel biomarker for predicting disease recurrence in Japanese patients with stage II CRC.     

Analysis of KRAS,NRAS, BRAF,PIK3CA and TP53 mutations in a large prospective series of locally advanced rectal cancer patients

Little information is available on the clinical significance of cancer-related genes such as KRAS, NRAS, BRAF, PIK3CA and TP53 in nonmetastatic rectal cancer. We investigated mutations of these genes in a large prospective series of locally advanced rectal cancer (LARC) patients who were recruited into two phase II trials. Mutational analyses were performed with diagnostically validated methods including polymerase chain reaction, capillary electrophoresis single-strand conformational analysis, Sanger sequencing and next-generation sequencing. Associations between single or multiple gene mutations and clinicopathological characteristics and treatment outcomes were explored. Of these 269, 210 (78%) patients were assessable. Mutations of KRAS, NRAS, BRAF, PIK3CA and TP53 occurred in 43, 9, 4, 9 and 60% of patients, respectively. Concordance between paired biopsy and resection specimens was 82% for KRAS, 95% for NRAS, 99% for BRAF, 96% for PIK3CA and 63% for TP53. TP53 mutations were associated with extramural venous invasion on baseline MRI (78% vs. 65%, p = 0.04), poor pathological tumour regression (23% vs. 36%, p = 0.05) and a trend toward a worse 5-year progression-free survival (PFS; 60% vs. 74%, HR 1.59, p = 0.06). Patients with tumours harbouring mutation of TP53 and either KRAS or NRAS (32%) had a worse 5-year PFS than those with TP53/KRAS/NRAS wild-type tumours (54% vs. 72%, HR 1.75, p = 0.02). In univariate analysis, BRAF mutation predicted poor 5-year overall survival only among patients treated without cetuximab (20% vs. 73%, HR 3.29, p = 0.03). This is one of the largest biomarker studies in a prospective, largely homogeneous, LARC population. Our findings are hypothesis generating and require validation in independent series.     

Oncogenic PIK3CA mutations in colorectal cancers and polyps

Oncogenic PIK3CA mutations contribute to colorectal tumorigenesis by activating AKT signaling to decrease apoptosis and increase tumor invasion. A synergistic association of PIK3CA mutation with KRAS mutation has been suggested to increase AKT signaling and resistance to antiepidermal growth factor receptor inhibitor therapy for advanced colorectal cancer, although studies have been conflicting. We sought to clarify this by examining PIK3CA mutation frequency in relation to other key molecular features of defined pathways of tumorigenesis. PIK3CA mutation was assessed by high resolution melt analysis in 829 colorectal cancer samples and 426 colorectal polyps. Mutations were independently correlated with clinicopathological features including patient age, sex and tumor location as well as molecular features including microsatellite instability, KRAS and BRAF mutation, MGMT methylation and the CpG Island Methylator Phenotype (CIMP). Mutation of the helical (Exon 9) and catalytic (Exon 20) domain mutation hotspots were also examined independently. Overall, PIK3CA mutation was positively correlated with KRAS mutation (p < 0.001), MGMT methylation (p = 0.007) and CIMP (p < 0.001). Novel, exon-specific associations linked Exon 9 mutations to a subgroup of cancers characterized by KRAS mutation, MGMT methylation and CIMP-Low, whilst Exon 20 mutations were more closely linked to features of serrated pathway tumors including BRAF mutation, microsatellite instability and CIMP-High or Low. PIK3CA mutations were uncommonly, but exclusively, seen in tubulovillous adenomas (4/124, 3.2%) and 1/4 (25.0%) tubulovillous adenomas with a focus of cancer. These data provide insight into the molecular events driving traditional versus serrated pathway tumorigenesis.     

PIK3CA exon 20 mutations as a potential biomarker for resistance to anti-EGFR monoclonal antibodies in KRAS wild-type metastatic colorectal cancer: a systematic review and meta-analysis

BackgroundWe conducted a systematic review and meta-analysis to dissect the association between PIK3CA mutations and resistance to anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (MoAbs) according to PIK3CA exon of mutations in metastatic colorectal cancer (mCRC).MethodsWe systematically identified studies exploring the association between PIK3CA mutations and clinical outcomes of mCRC patients treated with anti-EGFR MoAbs. The primary clinical outcomes included objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). The pooled relative risk (RR) or hazard ratio (HR) was estimated by using fixed effect model or random effect model according to heterogeneity between studies.ResultsThirteen studies were considered eligible, with 576 mCRC patients included. In KRAS wild-type mCRC patients, we observed a lower ORR in patients with PIK3CA exon 20 mutations [3 studies, 377 patients; ORR = 0% versus 37%; RR = 0.25; 95% confidence interval (CI) 0.05–1.19; P = 0.082], although the result was not statistically significant because of the small sample size. Only one study provided survival data according to the PIK3CA exon of the mutations, in which PIK3CA exon 20 mutations were statistically significantly associated with shorter PFS (HR = 2.52; 95% CI 1.33–4.78; P = 0.013) and OS (HR = 3.29; 95% CI 1.60–6.74; P = 0.006) in KRAS wild-type mCRC patients treated with anti-EGFR MoAbs. The predictive power of exon 20 mutation is greater than exon 9 mutations and all exons mutations in terms of ORR, PFS, and OS.ConclusionThese analyses suggest that PIK3CA exon 20 mutations may be a potential biomarker for resistance to anti-EGFR MoAbs in KRAS wild-type mCRC.     

Impact of KRAS,BRAF, PIK3CA,TP53 status and intraindividual mutation heterogeneity on outcome after liver resection for colorectal cancer metastases

We determined prognostic impact of KRAS, BRAF, PIK3CA and TP53 mutation status and mutation heterogeneity among 164 colorectal cancer (CRC) patients undergoing liver resections for metastatic disease. Mutation status was determined by Sanger sequencing of a total of 422 metastatic deposits. In univariate analysis, KRAS (33.5%), BRAF (6.1%) and PIK3CA (13.4%) mutations each predicted reduced median time to relapse (TTR) (7 vs. 22, 3 vs. 16 and 4 vs. 17 months; p < 0.001, 0.002 and 0.023, respectively). KRAS and BRAF mutations also predicted a reduced median disease‐specific survival (DSS) (29 vs. 51 and 16 vs. 49 months; p <0.001 and 0.008, respectively). No effect of TP53 (60.4%) mutation status was observed. Postoperative, but not preoperative chemotherapy improved both TTR and DSS (p < 0.001 for both) with no interaction with gene mutation status. Among 94 patients harboring two or more metastatic deposits, 13 revealed mutation heterogeneity across metastatic deposits for at least one gene. Mutation heterogeneity predicted reduced median DSS compared to homogeneous mutations (18 vs. 37 months; p = 0.011 for all genes; 16 vs. 26 months; p < 0.001 analyzing BRAF or KRAS mutations separately). In multivariate analyses, KRAS or BRAF mutations consistently predicted poor TRR and DSS. Mutation heterogeneity robustly predicted DSS but not TTR, while postoperative chemotherapy improved both TTR and DSS. Our findings indicate that BRAF and KRAS mutations as well as mutation heterogeneity predict poor outcome in CRC patients subsequent to liver resections and might help guide treatment decisions.