The Level of Preoperative Plasma KRAS Mutations and CEA Predict Survival of Patients Undergoing Surgery for Colorectal Cancer Liver Metastases

A prospective study of methylated ctDNA in patients undergoing treatment for liver metastases from colorectal cancer

BACKGROUND

Decision regarding local treatment of colorectal liver metastases (CRLM) is a multidisciplinary assessment, and liver intervention should be performed when the metastases are deemed resectable. There is no standard biomarker to aid neither this decision nor the postoperative treatment decisions. The present prospective, observational study aimed to investigate the potential clinical utility of a combined tumor-specific and organ-specific methylated circulating DNA assay in the perioperative setting of CRLM.

MATERIAL AND METHODS

The study included 56 cases with CRLM. Blood samples were drawn preoperatively and postoperatively. Multiplex methylation analysis of the markers NPY, KANK1, and GAL3ST3 (meth-ctDNA) was performed using droplet digital PCR.

RESULTS

The assay detected preoperative and postoperative meth-ctDNA in 37 % and 46 % of patients, respectively. Patients with negative preoperative meth-ctDNA had a longer median PFS compared to those with positive preoperative meth-ctDNA (HR = 2.2, 95 % CI 1.2-3.9, p < 0.01). In a multivariate analysis, preoperative negative meth-ctDNA was identified as a strong independent predictor of PFS (HR = 3.3, 95 % CI 1.5-7.2, p < 0.01). Similarly, patients with negative postoperative meth-ctDNA had longer median PFS (HR = 3.0, 95 % CI = 1.6-5.6, p < 0.001) and OS (HR = 4.1, 95 % CI 1.9-9.1, p < 0.001) compared to those with positive postoperative meth-ctDNA.

CONCLUSION

Preoperative meth-ctDNA may serve as an important biomarker to inform the multidisciplinary assessment and treatment planning of CRLM. Negative meth-ctDNA may indicate the optimal timing for liver intervention, whereas positive meth-ctDNA may indicate initiation or re-orientation of chemotherapy, or immediate local intervention. Our results confirm postoperative negative meth-ctDNA as a strong prognostic marker of survival.

The combined evaluation of preoperative serum CEA and postoperative tissue CEA as a prognostic factor in stages 0-IV colorectal cancer: a retrospective cohort study

Background

The roles of preoperative serum carcinoembryonic antigen (sCEA) and postoperative tissue carcinoembryonic antigen (tCEA) have been extensively studied in isolation in colorectal cancer (CRC). However, the combined role of sCEA and tCEA remains inadequately described.

Methods

A total of 1,757 retrospective cases of stage 0-IV CRC from January 2006 to January 2016 in our institution were included. Clinicopathological features and follow-up data were collected. Stage 0 was combined with stage I. sCEA levels were classified as normal or high (>10 ng/mL), while tCEA levels were categorised into three grades (+, ++, and +++). This resulted in six combined groups (2 × 3). ANOVA and cross-tabulation were employed to analyse continuous and categorical data, respectively. Univariate and multivariate analyses were conducted using Cox regression. All data were analysed using SPSS 27 and R 4.3.1.

Results

Some clinicopathologic features differed significantly among the combined CEA test groups (all p < 0.05). The receiver operating characteristic (ROC) curves for sCEA, tCEA, and combined CEA exhibited significant differences in five-year OS with death as the input variable (all p < 0.05). The area under the curve (AUC) for combined CEA was the highest, indicating the value of this study. Cox regression analysis demonstrated that tumour location, T stage, differentiation, chemotherapy, TNM stage, tCEA, and combined CEA were significant in the univariate analysis; however, tCEA was not significant (p = 0.096) in the multivariate analysis among these seven variables. Five-year OS analysis revealed that sCEA, tCEA, and combined CEA were not significant in stages 0 & I-II (all p > 0.05) but were significant in stages III-IV (all p < 0.05), except for tCEA in stage IV (p = 0.24) as per K-M and univariate analysis. No significant difference was observed between sCEA and tCEA (p = 0.55, 0.095), whereas combined CEA demonstrated a significant difference (p < 0.001) in both univariate and multivariate analyses.

Conclusion

sCEA, tCEA, and combined CEA exhibit prognostic roles in stages III-IV of CRC, with only combined CEA serving as an independent factor in these stages.

KRAS Mutations in Cholangiocarcinoma: Prevalence, Prognostic Value, and KRAS G12/G13 Detection in Cell-Free DNA

BACKGROUND/AIM

Cholangiocarcinoma (CCA) is an aggressive hepatobiliary malignancy characterized by genomic heterogeneity. KRAS mutations play a significant role in influencing patient prognosis and guiding therapeutic decision-making. This study aimed to determine the prevalence and prognostic significance of KRAS mutations in CCA, asses the detection of KRAS G12/G13 mutations in plasma cell-free DNA (cfDNA), and evaluate the prognostic value of KRAS G12/G13 mutant allele frequency (MAF) in cfDNA in relation to clinicopathological data and patient survival.

MATERIALS AND METHODS

A retrospective analysis of 937 CCA patients was performed using data from cBioPortal to examine KRAS mutation profiles and their association with survival. Plasma from 101 CCA patients was analyzed for KRAS G12/G13 mutations in the cfDNA using droplet digital PCR, and the results were compared with tissue-based sequencing from 78 matched samples.

RESULTS

KRAS driver mutations were found in 15.6% of patients, with common variants being G12D (37.0%), G12V (24.0%) and Q61H (8.2%). Patients harboring KRAS mutations exhibited decreased overall and recurrence-free survival. KRAS G12/G13 mutations were detected in 14.9% of cfDNA samples, showing moderate concordance with tissue sequencing, and achieving 80% sensitivity and 93% specificity. Elevated KRAS G12/G13 MAF in cfDNA, combined with high CA19-9 levels, correlated with poorer survival outcomes.

CONCLUSION

The presence of KRAS mutations was associated with poor survival in CCA, underscoring the importance of KRAS mutations as prognostic markers. The detection of KRAS mutations in cfDNA demonstrated potential as a promising non-invasive alternative for mutation detection and, when combined with CA19-9 levels, may improve prognostic efficacy in CCA.

Meta-analysis of the prognostic value of serum carcinoembryonic antigen in patients with colorectal cancer liver metastases after hepatectomy

OBJECTIVES

Carcinoembryonic antigen (CEA) is a broad-spectrum tumor marker for differential diagnosis, monitoring, and response assessment of a variety of malignancies. This meta-analysis was aimed at evaluating whether serum CEA could predict the prognosis in patients with colorectal cancer liver metastasis (CRCLM) before and after liver resection (LR).

METHODS

PubMed, Embase, Cochrane, and Web of Science were systematically searched to retrieve literature, with a search cutoff date of 27 February 2023. Articles were strictly screened for inclusion according to pre-specified inclusion and exclusion criteria. Data were pooled and analyzed using Stata 16.0.

RESULTS

This meta-analysis included 36 studies involving a total of 11 143 CRCLM patients. The results showed that a high pre-LR serum CEA level was correlated with poor overall survival (OS: HR = 1.61, 95% CI = 1.49-1.75, P  < 0.001) and recurrence-free survival (RFS: HR = 1.27, 95% CI = 1.11-1.45, P  < 0.001) in CRCLM patients. A high post-LR serum CEA level predicted poor overall survival (OS: HR = 2.66, 95% CI = 2.10-3.38, P  < 0.001).

CONCLUSION

High preoperative and postoperative serum CEA levels in patients with CRCLM were significantly associated with poor prognosis, independent of treatment modality, mode of analysis, case origin, and cutoff value classification.

BRAF mutation, selected miRNAs and genes expression in primary papillary thyroid carcinomas and local lymph node metastases

Mutations in cancer-related genes are now known to be accompanied by epigenetic events in carcinogenesis by modification of the regulatory pathways and expression of genes involved in the pathobiology. Such cancer-related mutations, miRNAs and gene expression may be promising molecular markers of the most common papillary thyroid carcinoma (PTC). However, there are limited data on their relationships. The aim of this study was to analyse the interactions between BRAF mutations, selected microRNAs (miR-21, miR-34a, miR-146b, and miR-9) and the expression of selected genes (LGALS3, NKX2-1, TACSTD2, TPO) involved in the pathogenesis of PTC. The study cohort included 60 primary papillary thyroid carcinomas (PTC) that were classified as classical (PTC/C; n=50) and invasive follicular variant (PTC/F; n=10), and 40 paired lymph node metastases (LNM). BRAF mutation status in primary and recurrent/persistent papillary thyroid carcinomas was determined. The mutation results were compared both between primary and metastatic cancer tissue, and between BRAF mutation status and selected genes and miRNA expression in primary PTC. Furthermore, miRNAs and gene expression were compared between primary PTCs and non-neoplastic tissue, and local lymph node metastatic tumor, respectively. All studied markers showed several significant mutual interactions and contexts. In conclusion, to the best our knowledge, this is the first integrated study of BRAF mutational status, the expression levels of mRNAs of selected genes and miRNAs in primary PTC, and paired LNM.

Molecular profiling and patient selection for the multimodal approaches for patients with resectable colorectal liver metastases

Colorectal cancer represents the third most common cancer and about 20% are diagnosed with synchronous metastatic disease. From a historical point of view, surgery remains the mainstream treatment for resectable colorectal liver metastases (CRLM). Furthermore, disease outcomes are improving due significant advances in systemic treatments and diagnostic methods. However, the optimal timing for neoadjuvant chemotherapy or upfront surgery for CRLM has not yet been established and remains an open question. Thus, patient selection combining image workouts, time of recurrence, positive lymph nodes, and molecular biomarkers can improve the decision-making process. Nevertheless, molecular profiling is rising as a promising field to be incorporated in the multimodal approach and guide patient selection and sequencing of treatment. Tumor biomakers, genetic profiling, and circulating tumor DNA have been used to offer as much personalized treatment as possible, based on the precision oncology concept of tailored care rather than a guideline-based therapy. This review article discusses the role of molecular pathology and biomarkers as prognostic and predictor factors in the diagnosis and treatment of resectable CRLM.

Prognostic role of serum carcinoembryonic antigen in patients receiving liver resection for colorectal cancer liver metastasis: A meta-analysis

BACKGROUND

Carcinoembryonic antigen (CEA) is a broad-spectrum tumor marker for differential diagnosis, monitoring, and response assessment of a variety of malignancies.

AIM

To evaluate whether serum CEA could predict the prognosis in patients with colorectal cancer liver metastasis (CRCLM) before and after liver resection (LR).

METHODS

PubMed, Embase, Cochrane, and Web of Science were systematically searched to retrieve literature, with a search cut-off date of February 27, 2023. Articles were strictly screened for inclusion according to pre-specified inclusion and exclusion criteria. Data were pooled and analyzed using Stata 16.0.

RESULTS

This meta-analysis included 36 studies involving a total of 11143 CRCLM patients. The results showed that a high pre-LR serum CEA level was correlated with poor overall survival (OS) [hazard ratio (HR) = 1.61, 95% confidence interval (CI): 1.49-1.75, P < 0.001] and recurrence-free survival (HR = 1.27, 95%CI: 1.11-1.45, P < 0.001) in CRCLM patients. A high post-LR serum CEA level predicted poor OS (HR = 2.66, 95%CI: 2.10-3.38, P < 0.001). A comparison by treatment modality, analysis modality, patient source, and cutoff-value showed that overall, high preoperative and postoperative serum CEA levels remained correlated with a poor prognosis.

CONCLUSION

This study concluded that high pre-LR and post-LR serum CEA levels were significantly correlated with a poor prognosis in CRCLM patients.

Circulating Tumour DNA as Biomarker for Colorectal Liver Metastases: A Systematic Review and Meta-Analysis

Circulating tumour DNA (ctDNA) is a potential biomarker that could contribute to more judicious patient selection for personalised treatment. This review and meta-analysis gives an overview of the current knowledge in the literature investigating the value of ctDNA in patients with colorectal liver metastases (CRLM). A systematic search was conducted in electronic databases for studies published prior to the 26th of May 2023. Studies investigating the association between ctDNA and oncological outcomes in patients undergoing curative-intent local therapy for CRLM were included. Meta-analyses were performed to pool hazard ratios (HR) for the recurrence-free survival (RFS) and overall survival (OS). A total of eleven studies were included and nine were eligible for meta-analyses. Patients with detectable ctDNA after surgery experienced a significantly higher chance of recurrence (HR 3.12, 95% CI 2.27-4.28, p < 0.000010) and shorter OS (HR 5.04, 95% CI 2.53-10.04, p < 0.00001) compared to patients without detectable ctDNA. A similar association for recurrence was found in patients with detectable ctDNA after the completion of adjuvant therapy (HR 6.39, 95% CI 2.13-19.17, p < 0.0009). The meta-analyses revealed no association between detectable ctDNA before surgery and the RFS and OS. These meta-analyses demonstrate the strong association between detectable ctDNA after treatment and oncological outcomes in CRLM patients.

Circulating tumour DNA at baseline for individualised prognostication in patients with chemotherapy-naïve metastatic colorectal cancer. An AGEO prospective study

PURPOSE

Baseline circulating tumour DNA (ctDNA) is a potential prognostic marker in metastatic colorectal cancer (mCRC) patients. However, few studies have compared ctDNA with the usual prognostic factors, and no ctDNA cut-off has been proposed for daily use in clinical practice.

PATIENTS AND METHODS

Chemotherapy-naive patients with mCRC were prospectively included. Plasma samples were collected at diagnosis and analysed centrally by both NGS and methylation digital PCR. Baseline patient and disease characteristics, treatment regimens, and secondary surgeries were collected. The restricted cubic spline method was used to define the optimal cut-off of ctDNA mutated allelic frequency (MAF). Prognostic values were assessed on overall survival (OS) using Cox models.

RESULTS

From July 2015 to December 2016, 412 patients were included. ctDNA was undetectable in 83 patients (20%). ctDNA was an independent prognostic marker for OS considering the whole study population. The optimal cut-off for ctDNA MAF was 20% with median OS of 16.0 and 35.8 months for patients with MAF ≥20% and<20%, respectively (hazard ratio = 0.40; 95% confidence intervals: 0.31-0.51; P < 0.0001). The independent prognostic value of ctDNA MAF at 20% was confirmed in subgroups defined by RAS/BRAF status or resectability of metastases. Combining ctDNA MAF and carcinoembryonic antigen levels allowed us to define three different prognostic groups with median OS of 14.2, 21.1, and 46.4 months (P < 0.0001).

CONCLUSION

ctDNA with a MAF cut-off of 20% improves prognostication of chemotherapy-naïve mCRC patients and may be useful in the future for individualised therapeutic decisions and as a stratification factor in clinical trials.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT02502656.

ctDNA as a prognostic biomarker in resectable CLM: Systematic review and meta-analysis

Cell-free circulating tumor DNA (ctDNA) is synthesized by tumor cells, including metastatic tumors, and circulates in the bloodstream. Evidence suggests that ctDNA is a potential predictive and prognostic biomarker for colorectal cancer (CRC), but its predictive efficacy in detecting CRC liver metastasis (CLM) remains unclear. Additionally, its utility in the clinical setting needs further investigation. We conducted a meta-analysis to determine the utility of ctDNA as a biomarker for predicting the prognosis of CLM and investigate the relationship between CLM and ctDNA positivity. A literature search was performed in electronic databases to identify relevant studies published up to March 19, 2022. We retrieved data on overall survival (OS), disease-free survival (DFS), and recurrence-free survival (RFS) for both ctDNA-positive and ctDNA-negative colorectal liver metastasis (CLM) patients from the selected articles. Hazard ratios (HRs) were also calculated for these survival outcomes analysis was also performed. The stability of the combined meta-analysis was verified by sensitivity analysis and publication bias evaluation. Ten trials were included, and 615 patients were evaluated. In patients with CLM, pooled HRs revealed a substantial link between ctDNA positivity and RFS/DFS. Subgroup analysis revealed that ctDNA had a prospective detection value. Sensitivity analysis and publication bias evaluation indicated stable results. Although the results on pooled HR for OS suggested that ctDNA-positive patients had a shorter survival time, their pooled HRs had a relatively evident heterogeneity, and sensitivity analysis and publication bias evaluation indicated that pooled HRs were extremely unstable. In conclusion, our results demonstrate that ctDNA appears to be a prognostic biomarker for resectable CLM patients.

Circulating Tumor DNA-A Novel Biomarker of Tumor Progression and Its Favorable Detection Techniques

Cancer is the second leading cause of death in the world and seriously affects the quality of life of patients. The diagnostic techniques for tumors mainly include tumor biomarker detection, instrumental examination, and tissue biopsy. In recent years, liquid technology represented by circulating tumor DNA (ctDNA) has gradually replaced traditional technology with its advantages of being non-invasive and accurate, its high specificity, and its high sensitivity. ctDNA may carry throughout the circulatory system through tumor cell necrosis, apoptosis, circulating exosome secretion, etc., carrying the characteristic changes in tumors, such as mutation, methylation, microsatellite instability, gene rearrangement, etc. In this paper, ctDNA mutation and methylation, as the objects to describe the preparation process before ctDNA analysis, and the detection methods of two gene-level changes, including a series of enrichment detection techniques derived from PCR, sequencing-based detection techniques, and comprehensive detection techniques, are combined with new materials. In addition, the role of ctDNA in various stages of cancer development is summarized, such as early screening, diagnosis, molecular typing, prognosis prediction, recurrence monitoring, and drug guidance. In summary, ctDNA is an ideal biomarker involved in the whole process of tumor development.

Liquid Biopsies in Colorectal Liver Metastases: Towards the Era of Precision Oncologic Surgery

Tumor mutational analysis has been incorporated into the management of patients with CRLM since it can provide valuable prognostic information as well as guide peri-operative systemic treatment. Unlike tumor biopsy, liquid biopsy has emerged as a promising, non-invasive alternative that can detect cell-derived markers from a variety of body fluids and might better characterize all subclones present at a specific time point and allow sequential monitoring of disease evolution. Although not currently considered standard of care, an increasing number of cancer centers are nowadays routinely using liquid biopsies in the treatment of CRLM patients with promising results. The current review provides an overview of liquid biopsies in cancer therapeutics and focuses on the application of this relatively new approach on patients with CRLM.

The implications of cell-free DNAs derived from tumor viruses as biomarkers of associated cancers

Cancer is still ranked as a leading cause of death according to estimates from the World Health Organization (WHO) and the strong link between tumor viruses and human cancers have been proved for almost six decades. Cell-free DNA (cfDNA) has drawn enormous attention for its dynamic, instant, and noninvasive advantages as one popular type of cancer biomarker. cfDNAs are mainly released from apoptotic cells and exosomes released from cancer cells, including those infected with viruses. Although cfDNAs are present at low concentrations in peripheral blood, they can reflect tumor load with high sensitivity. Considering the relevance of the tumor viruses to the associated cancers, cfDNAs derived from viruses may serve as good biomarkers for the early screening, diagnosis, and treatment monitoring. In this review, we summarize the methods and newly developed analytic techniques for the detection of cfDNAs from different body fluids, and discuss the implications of cfDNAs derived from different tumor viruses in the detection and treatment monitoring of virus-associated cancers. A better understanding of cfDNAs derived from tumor viruses may help formulate novel anti-tumoral strategies to decrease the burden of cancers that attributed to viruses. This article is protected by copyright. All rights reserved.

Application of artificial intelligence in a real-world research for predicting the risk of liver metastasis in T1 colorectal cancer

Background

Liver is the most common metastatic site of colorectal cancer (CRC) and liver metastasis (LM) determines subsequent treatment as well as prognosis of patients, especially in T1 patients. T1 CRC patients with LM are recommended to adopt surgery and systematic treatments rather than endoscopic therapy alone. Nevertheless, there is still no effective model to predict the risk of LM in T1 CRC patients. Hence, we aim to construct an accurate predictive model and an easy-to-use tool clinically.

Methods

We integrated two independent CRC cohorts from Surveillance Epidemiology and End Results database (SEER, training dataset) and Xijing hospital (testing dataset). Artificial intelligence (AI) and machine learning (ML) methods were adopted to establish the predictive model.

Results

A total of 16,785 and 326 T1 CRC patients from SEER database and Xijing hospital were incorporated respectively into the study. Every single ML model demonstrated great predictive capability, with an area under the curve (AUC) close to 0.95 and a stacking bagging model displaying the best performance (AUC = 0.9631). Expectedly, the stacking model exhibited a favorable discriminative ability and precisely screened out all eight LM cases from 326 T1 patients in the outer validation cohort. In the subgroup analysis, the stacking model also demonstrated a splendid predictive ability for patients with tumor size ranging from one to50mm (AUC = 0.956).

Conclusion

We successfully established an innovative and convenient AI model for predicting LM in T1 CRC patients, which was further verified in the external dataset. Ultimately, we designed a novel and easy-to-use decision tree, which only incorporated four fundamental parameters and could be successfully applied in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02424-7.

Metastatic Colorectal Cancer

International experts in the study of metastatic colorectal cancer (mCRC) present this series of 14 articles (eleven original articles and three literature reviews) [...].

Current and Emerging Applications of Droplet Digital PCR in Oncology: An Updated Review

In the era of personalized medicine and targeted therapies for the management of patients with cancer, ultrasensitive detection methods for tumor genotyping, such as next-generation sequencing or droplet digital polymerase chain reaction (ddPCR), play a significant role. In the search for less invasive strategies for diagnosis, prognosis and disease monitoring, the number of publications regarding liquid biopsy approaches using ddPCR has increased substantially in recent years. There is a long list of malignancies in which ddPCR provides a reliable and accurate tool for detection of nucleic acid-based markers derived from cell-free DNA, cell-free RNA, circulating tumor cells, extracellular vesicles or exosomes when isolated from whole blood, plasma and serum, helping to anticipate tumor relapse or unveil intratumor heterogeneity and clonal evolution in response to treatment. This updated review describes recent developments in ddPCR platforms and provides a general overview about the major applications of liquid biopsy in blood, including its utility for molecular response and minimal residual disease monitoring in hematological malignancies or the therapeutic management of patients with colorectal or lung cancer, particularly for the selection and monitoring of treatment with tyrosine kinase inhibitors. Although plasma is the main source of genetic material for tumor genomic profiling, liquid biopsy by ddPCR is being investigated in a wide variety of biologic fluids, such as cerebrospinal fluid, urine, stool, ocular fluids, sputum, saliva, bronchoalveolar lavage, pleural effusion, mucin, peritoneal fluid, fine needle aspirate, bile or pancreatic juice. The present review focuses on these "alternative" sources of genetic material and their analysis by ddPCR in different kinds of cancers.

Clinical Applications of Minimal Residual Disease Assessments by Tumor-Informed and Tumor-Uninformed Circulating Tumor DNA in Colorectal Cancer

Simple Summary

Circulating tumor DNA, or ctDNA, are fragments of tumor DNA that can be detected in the blood of patients with colorectal cancer. Measuring ctDNA levels in the blood has shown the potential to provide important information that can be helpful in the clinical care of patients with colorectal cancer. For example, in patients with colon cancer that has been removed by surgery, measuring ctDNA in the blood can predict the likelihood of cancer recurrence, while in those with metastatic colorectal cancer, measuring ctDNA can inform the clinician whether chemotherapy is effective at earlier timepoints than currently available tests. In this review, we discuss the results from ongoing studies describing the utility of ctDNA measurements across all stages of colorectal cancer. We also discuss the various clinical scenarios that ctDNA may have the most immediate impact in colorectal cancer management.

Abstract

Emerging data suggest that circulating tumor DNA (ctDNA) can detect colorectal cancer (CRC)-specific signals across both non-metastatic and metastatic settings. With the development of multiple platforms, including tumor-informed and tumor-agnostic ctDNA assays and demonstration of their provocative analytic performance to detect minimal residual disease, there are now ongoing, phase III randomized clinical trials to evaluate their role in the management paradigm of CRC. In this review, we highlight landmark studies that have formed the basis for ongoing studies on the clinically applicability of plasma ctDNA assays in resected, stage I–III CRC and metastatic CRC. We discuss clinical settings by which ctDNA may have the most immediate impact in routine clinical practice. These include the potential for ctDNA to (1) guide surveillance and intensification or de-intensification strategies of adjuvant therapy in resected, stage I–III CRC, (2) predict treatment response to neoadjuvant therapy in locally advanced rectal cancer inclusive of total neoadjuvant therapy (TNT), and (3) predict response to systemic and surgical therapies in metastatic disease. We end by considering clinical variables that can influence our ability to reliably interpret ctDNA dynamics in the clinic.

Biomarkers in colorectal liver metastases: Rising complexity and unknown clinical significance?

Surgical resection of the liver is the standard treatment for colorectal liver metastases, but 70% of patients still experience recurrence, resulting in limited survival. Molecular biomarkers promise guidance within the selection process of individualized treatment and provide better prognostic forecasting of recurrence and response to treatment. Presently, most investigated biomarkers include mutations of KRAS, BRAF, TP53, PIK3CA, APC, expression of Ki-67, and microsatellite instability. As some colorectal cancer tumors exhibit more than one molecular target, in line with a rising number of potential biomarkers, the complexity of their clinical implementation is rising steadily. Therefore, it is important to approach new insights into molecular biomarkers with explicit caution to their clinical applicability and significance, as there are contradictory results arising from multiple available studies and meta-analyses. This review helps to shed light on the complexity of promising biomarkers in both the prognosis and diagnosis of colorectal liver metastases.

Genomic and prognostic heterogeneity among RAS/BRAFV600E /TP53 co-mutated resectable colorectal liver metastases

Hepatic resection is potentially curative for patients with colorectal liver metastases, but the treatment benefit varies. KRAS/NRAS (RAS)/TP53 co‐mutations are associated with a poor prognosis after resection, but there is large variation in patient outcome within the mutation groups, and genetic testing is currently not used to evaluate benefit from surgery. We have investigated the potential for improved prognostic stratification by combined biomarker analysis with DNA copy number aberrations (CNAs), and taking tumor heterogeneity into account. We determined the mutation status of RAS, BRAF^V600, and TP53 in 441 liver lesions from 171 patients treated by partial hepatectomy for metastatic colorectal cancer. CNAs were profiled in 232 tumors from 67 of the patients. Mutations and high‐level amplifications of cancer‐critical genes, the latter including ERBB2 and EGFR, were predominantly homogeneous within patients. RAS/BRAF^V600E and TP53 co‐mutations were associated with a poor patient outcome (hazard ratio, HR, 3.9, 95% confidence interval, CI, 1.3–11.1, P = 0.012) in multivariable analyses with clinicopathological variables. The genome‐wide CNA burden and intrapatient intermetastatic CNA heterogeneity varied within the mutation groups, and the CNA burden had prognostic associations in univariable analysis. Combined prognostic analyses of RAS/BRAF^V600E/TP53 mutations and CNAs, either as a high CNA burden or high intermetastatic CNA heterogeneity, identified patients with a particularly poor outcome (co‐mutation/high CNA burden: HR 2.7, 95% CI 1.2–5.9, P = 0.013; co‐mutation/high CNA heterogeneity: HR 2.5, 95% CI 1.1–5.6, P = 0.022). In conclusion, DNA copy number profiling identified genomic and prognostic heterogeneity among patients with resectable colorectal liver metastases with co‐mutated RAS/BRAF^V600E/TP53.