BRAF mutation in metastatic colorectal cancer

Management of Metastatic Colorectal Carcinoma in Older Adults: Balancing Risks and Benefits of Novel Therapies

The prevalence of older patients with metastatic colorectal cancer (mCRC) will continue to increase with our aging population. Treatment of mCRC has changed significantly in the last few decades as we have learned how to personalize the treatment of mCRC to the biology of the tumor, utilizing new treatment approaches. With an ever-changing treatment paradigm, managing the population of older adults becomes paramount. This review highlights the pivotal clinical trials that defined the use of systemic therapy, immunotherapy and targeted therapies for mCRC, and how those are applied to the older patient population. In addition, we outline the tools for an in-depth assessment of an older adult in regards to treatment planning and management of therapy-related toxicities. A comprehensive geriatric assessment can assist in the selection of treatment for an older adult with mCRC. While frail older patients can frequently only tolerate single agents or modified regimens, fit older adults remain candidates for a wider range of treatment options. However, since all of these treatments are associated with possible toxicities, each patient's treatment must be personalized to the patient's goals and wishes through a shared decision-making process.

Precision oncology in metastatic colorectal cancer - from biology to medicine

Remarkable progress has been made in the development of biomarker-driven targeted therapies for patients with multiple cancer types, including melanoma, breast and lung tumours, although precision oncology for patients with colorectal cancer (CRC) continues to lag behind. Nonetheless, the availability of patient-derived CRC models coupled with in vitro and in vivo pharmacological and functional analyses over the past decade has finally led to advances in the field. Gene-specific alterations are not the only determinants that can successfully direct the use of targeted therapy. Indeed, successful inhibition of BRAF or KRAS in metastatic CRCs driven by activating mutations in these genes requires combinations of drugs that inhibit the mutant protein while at the same time restraining adaptive resistance via CRC-specific EGFR-mediated feedback loops. The emerging paradigm is, therefore, that the intrinsic biology of CRC cells must be considered alongside the molecular profiles of individual tumours in order to successfully personalize treatment. In this Review, we outline how preclinical studies based on patient-derived models have informed the design of practice-changing clinical trials. The integration of these experiences into a common framework will reshape the future design of biology-informed clinical trials in this field.

Current therapy of advanced colorectal cancer according to RAS/RAF mutational status

Colorectal cancer is a clinically and molecularly heterogeneous disease. Currently, extended RAS and BRAF mutation testing is obligatory in routine clinical practice before starting any treatment in the metastatic setting. Treatment decision making also includes assessment of the clinical condition of the patient, definition of the treatment goal, and consideration of the primary tumor site. Biological treatment is part of the first-line drug combination unless contraindicated. Mutational status is significantly associated with the outcome of patients and is strongly predictive for anti-EGFR-targeted therapy. The prognosis of RAS mutant CRC is clearly inferior to wild-type cases. RAS remains an elusive target, and specific treatment options are not yet available. Recently, promising results of a direct KRAS G12C inhibitor have been reported; however, further confirmation is needed. The biomarker landscape in mCRC is evolving; new promising markers are awaited with the chance of more precise targeted treatment.

Oncological evaluation in the perioperative period using cfDNA with BRAF V600E mutation in patients with colorectal cancer

The detection of circulating cell-free DNA (cfDNA) by liquid biopsy is reported to provide prognostic information in colorectal cancer (CRC). Although the frequency of BRAF V600E mutation in CRC is less than 10%, it is associated with poor responses to conventional chemotherapy. We conducted a prospective study to investigate the relationship between the perioperative mutant allele frequency (MAF) of BRAF V600E and tumor recurrence, and to evaluate the possibility of early detection of recurrence. Among 362 patients who underwent radical resection, cfDNA was extracted from the perioperative blood of 11 CRC patients with BRAF V600E mutation and analyzed using the digital polymerase chain reaction (dPCR) system. The median follow-up time was 22 months, and there were four cases of recurrence. Although there was no correlation between recurrence and the perioperative MAF of BRAF V600E, tumor diameter was correlated with the MAF (p = 0.024), and the MAF increased with time in two patients from whom additional samples were obtained prior to recurrence. In this study, we identified a correlation between the pathological tumor diameter and the MAF, but it was difficult to predict recurrence by measuring cfDNA with BRAF V600E mutation in the perioperative period of radical resection of CRC.

Preclinical models as patients' avatars for precision medicine in colorectal cancer: past and future challenges

Colorectal cancer (CRC) is a complex and heterogeneous disease, characterized by dismal prognosis and low survival rate in the advanced (metastatic) stage. During the last decade, the establishment of novel preclinical models, leading to the generation of translational discovery and validation platforms, has opened up a new scenario for the clinical practice of CRC patients. To bridge the results developed at the bench with the medical decision process, the ideal model should be easily scalable, reliable to predict treatment responses, and flexibly adapted for various applications in the research. As such, the improved benefit of novel therapies being tested initially on valuable and reproducible preclinical models would lie in personalized treatment recommendations based on the biology and genomics of the patient's tumor with the overall aim to avoid overtreatment and unnecessary toxicity. In this review, we summarize different in vitro and in vivo models, which proved efficacy in detection of novel CRC culprits and shed light into the biology and therapy of this complex disease. Even though cell lines and patient-derived xenografts remain the mainstay of colorectal cancer research, the field has been confidently shifting to the use of organoids as the most relevant preclinical model. Prioritization of organoids is supported by increasing body of evidence that these represent excellent tools worth further therapeutic explorations. In addition, novel preclinical models such as zebrafish avatars are emerging as useful tools for pharmacological interrogation. Finally, all available models represent complementary tools that can be utilized for precision medicine applications.

Treatment sequencing of metastatic colorectal cancer based on primary tumor location

Colorectal cancer is a heterogeneous disease with various clinical, molecular, and embryological differences related to the origin of the tumor from the right or left colon. Recent studies have demonstrated that tumor sidedness has both a prognostic and predictive value in metastatic colorectal cancer . Patients whose primary tumor originates from the left side of the colon and whose tumor's genome encodes wild-type RAS and BRAF should be offered cetuximab or panitumumab in the first-line treatment of metastatic disease or in subsequent lines. For tumors originating from the right side of the colon, anti-angiogenic treatment, particularly bevacizumab, is an option for this poor prognostic group until better options become available. Specifically, an aggressive initial approach with FOLFOXIRI plus bevacizumab is a treatment option in right-sided tumors under investigation. This report reviews the available data for the treatment of metastatic colorectal cancer according to the location of the primary tumor and proposes the optimal treatment sequencing strategy incorporating the site of origin of the tumor and molecular information into the decision-making process.

Impact of BRAF mutations on clinical outcomes following liver surgery for colorectal liver metastases: An updated meta-analysis

BACKGROUND

Data regarding clinical outcomes of patients undergoing hepatic resection for BRAF-mutated colorectal liver metastases (CRLM) are scarce. Most of the studies report an impaired median overall survival (OS) in BRAF-mutated patients, but controversial Results regarding both recurrence-free survival (RFS) and recurrence patterns. The purpose of this updated meta-analysis was to better precise the impact of BRAF mutations on clinical outcomes following liver surgery for CRLM study, especially on recurrence.

METHODS

A systematic literature review was performed to identify articles reporting clinical outcomes including both OS and RFS, recurrence patterns, and clinicopathological details of patients who underwent complete liver resection for CRLM, stratified according to BRAF mutational status.

RESULTS

Thirteen retrospective studies, including 5192 patients, met the inclusion criteria. The analysis revealed that both OS (OR = 1.981; 95% CI = [1.613-2.432]) and RFS (OR = 1.49; 95% CI [1.01-2.21]) were impaired following liver surgery for CRLM in BRAF-mutated patients. Risks of both hepatic (OR = 0.42; 95% CI [0.18-0.98]) and extrahepatic recurrences (OR = 0.53; 95% CI [0.33-0.83] were significantly higher in BRAF-mutated patients. These patients tended to have higher rates of right-sided colon primary tumors, primary positive lymph nodes, and multiple CRLM.

CONCLUSIONS

This meta-analysis confirms that BRAF mutations impair both OS and RFS following liver surgery. Therefore, BRAF mutational status should probably be included in further prognostic scores for the assessment of the expected clinical outcomes following surgery for CRLM.

Management of BRAF-mutant metastatic colorectal cancer: a review of treatment options and evidence-based guidelines

BACKGROUND

Colorectal cancer (CRC) is still a leading cause of cancer-related deaths in the United States and worldwide, despite recent improvements in cancer management. CRC, like many malignancies, is a heterogeneous disease, with subtypes characterized by genetic alterations. One common mutation in CRC is in the BRAF gene (most commonly V600E substitution). This occurs in ∼10% of patients with metastatic CRC (mCRC) and is a marker of poor prognosis.

DESIGN

Herein, we review the clinical and translational literature on the role of the BRAF V600E mutation in the pathogenesis of mCRC, its mechanisms as a prognostic marker, and its potential utility as a predictive marker of treatment response. We then summarize the current evidence-based recommendations for management of BRAF V600E-mutated mCRC, with a focus on recent clinical research advances in this setting.

RESULTS

The current standard therapies for first-line treatment of BRAF-mutated mCRC are chemotherapy with bevacizumab as well as 5-fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI) plus bevacizumab in patients with a good performance status. Combination strategies involving mitogen-activated protein kinase (MAPK) pathway blockade have shown promising results for the treatment of patients with BRAF V600E-mutated mCRC. The Binimetinib, Encorafenib, And Cetuximab cOmbiNed to treat BRAF-mutant ColoRectal Cancer (BEACON CRC) study represents the largest study in this population to date and has given strong clinical evidence to support BRAF and epidermal growth factor receptor inhibition with the combination of encorafenib plus cetuximab.

CONCLUSIONS

The treatment of BRAF-mutated mCRC has evolved rapidly over the last several years. Recently, combination strategies involving MAPK pathway blockade have shown promising results in BRAF V600E-mutated mCRC, and other potential targets continue to be explored. In addition, a greater understanding of the role of BRAF V600E mutation in the pathogenesis of CRC should also continue to fuel advances in the management of patients with mCRC harboring this genetic aberration.

Rational Treatment of Metastatic Colorectal Cancer: A Reverse Tale of Men, Mice, and Culture Dishes

Stratification of colorectal cancer into subgroups with different response to therapy was initially guided by descriptive associations between specific biomarkers and treatment outcome. Recently, preclinical models based on propagatable patient-derived tumor samples have yielded an improved understanding of disease biology, which has facilitated the functional validation of correlative information and the discovery of novel response determinants, therapeutic targets, and mechanisms of tumor adaptation and drug resistance. We review the contribution of patient-derived models to advancing colorectal cancer characterization, discuss their influence on clinical decision-making, and highlight emerging challenges in the interpretation and clinical transferability of results obtainable with such approaches. SIGNIFICANCE: Association studies in patients with colorectal cancer have led to the identification of response biomarkers, some of which have been implemented as companion diagnostics for therapeutic decisions. By enabling biological investigation in a clinically relevant experimental context, patient-derived colorectal cancer models have proved useful to examine the causal role of such biomarkers in dictating drug sensitivity and are providing fresh knowledge on new actionable targets, dynamics of tumor evolution and adaptation, and mechanisms of drug resistance.

Systemic therapy in addition to cytoreduction and hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases: recent insights from clinical studies and translational research

There is a lack of randomized or high-quality intention-to-treat cohort studies addressing the role of systemic therapy in addition to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) as part of the treatment of colorectal peritoneal metastases (PM). Therefore, the choice whether or not to treat patients with systemic therapy is currently mainly based on expert opinion. As a result, treatment with neoadjuvant and/or adjuvant systemic therapy is implemented in various ways around the world. The aim of this review was to provide an overview of recent insights with regard to the systemic treatment of PM of colorectal origin obtained from clinical studies and translational research.

Management of BRAF Gene Alterations in Metastatic Colorectal Cancer: From Current Therapeutic Strategies to Future Perspectives

BRAF mutations constitute an important poor prognostic factor in metastatic colorectal cancer (mCRC) and the development of treatments in this context is of great necessity to prolong patient survival. Although the association between BRAF mutations and microsatellite instability (MSI) has been known for several years, previous clinical trials have revealed that the former has a limited prognostic impact and that immune checkpoint inhibitors offer a significant survival benefit to mCRC patients with both characteristics. Furthermore, the genomic classification of BRAF mutations according to their molecular functions enables greater understanding of the characteristics of mCRC patients with BRAF mutations, with therapeutic strategies based on this classification made more ideal to improve poor prognosis through the delivery of targeted therapies. Recently, a phase III trial was conducted in previously treated mCRC patients with BRAF V600E-mutated tumors and revealed that the combination therapy approach of BRAF inhibition and anti-epidermal growth factor receptor antibody therapy with or without MEK inhibition was more efficacious than standard chemotherapy alone. This review discusses current treatment strategies and future perspectives in BRAF-mutated mCRC.

Colon Cancer, Version 2.2021, NCCN Clinical Practice Guidelines in Oncology

This selection from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Colon Cancer focuses on systemic therapy options for the treatment of metastatic colorectal cancer (mCRC), because important updates have recently been made to this section. These updates include recommendations for first-line use of checkpoint inhibitors for mCRC, that is deficient mismatch repair/microsatellite instability-high, recommendations related to the use of biosimilars, and expanded recommendations for biomarker testing. The systemic therapy recommendations now include targeted therapy options for patients with mCRC that is HER2-amplified, or BRAF V600E mutation-positive. Treatment and management of nonmetastatic or resectable/ablatable metastatic disease are discussed in the complete version of the NCCN Guidelines for Colon Cancer available at NCCN.org. Additional topics covered in the complete version include risk assessment, staging, pathology, posttreatment surveillance, and survivorship.

DRP1 Promotes BRAFV600E-Driven Tumor Progression and Metabolic Reprogramming in Colorectal Cancer

Background

Mitochondria are highly dynamic organelles which remain in a continuous state of fission/ fusion dynamics to meet the metabolic needs of a cell. However, this fission/fusion dynamism has been reported to be dysregulated in most cancers. Such enhanced mitochondrial fission is demonstrated to be positively regulated by some activating oncogenic mutations; such as those of KRAS (Kristen rat sarcoma viral oncogene homologue) or BRAF (B- rapidly accelerated fibrosarcoma), thereby increasing tumor progression/ chemotherapeutic resistance and metabolic deregulation. However, the underlying mechanism(s) are still not clear, thus highlighting the need to further explore possible mechanism(s) of intervention. We sought to investigate how BRAF^V600E driven CRC (colorectal cancer) progression is linked to mitochondrial fission/fusion dynamics and whether this window could be exploited to target CRC progression.

Methods

Western blotting was employed to study the differences in expression levels of key proteins regulating mitochondrial dynamics, which was further confirmed by confocal microscopy imaging of mitochondria in endogenously expressing BRAF^WT and BRAF^V600E CRC cells. Proliferation assays, soft agar clonogenic assays, glucose uptake/lactate production, ATP/ NADPH measurement assays were employed to study the extent of carcinogenesis and metabolic reprograming in BRAF^V600E CRC cells. Genetic knockdown (shRNA/ siRNA) and/or pharmacologic inhibition of Dynamin related protein1/Pyruvate dehydrogenase kinase1 (DRP1/PDK1) and/or BRAF^V600E were employed to study the involvement and possible mechanism of these proteins in BRAF^V600E driven CRC. Statistical analyses were carried out using Graph Pad Prism v 5.0, data was analyzed by unpaired t-test and two-way ANOVA with appropriate post hoc tests.

Results

Our results demonstrate that BRAF^V600E CRC cells have higher protein levels of mitochondrial fission factor- DRP1/pDRP1^S616 leading to a more fragmented mitochondrial state compared to those harboring BRAF^WT . This fragmented mitochondrial state was found to confer glycolytic phenotype, clonogenic potential and metastatic advantage to cells harboring BRAF^V600E . Interestingly, such fragmented mitochondrial state seemed positively regulated by mitochondrial PDK1 as observed through pharmacologic as well as genetic inhibition of PDK1.

Conclusion

In conclusion, our data suggest that BRAF^V600E driven colorectal cancers have fragmented mitochondria which confers glycolytic phenotype and growth advantage to these tumors, and such phenotype is dependent at least in part on PDK1- thus highlighting a potential therapeutic target.

Clinicopathological Features and Prognostic Value of KRAS/NRAS/BRAF Mutations in Colorectal Cancer Patients of Central China

The incidence of colorectal cancer (CRC) is increasing in China, with high mortality. Here, we aimed to evaluate the latest clinicopathological features and prognostic value of the KRAS/NRAS/BRAF mutation status in CRC patients in Central China. The clinical data of 1549 CRC patients with stage I-IV disease diagnosed at Union Hospital, Tongji Medical College of Huazhong University of Science and Technology from 2015 to 2017 were collected and analyzed retrospectively. KRAS/NRAS/BRAF mutations were detected by real-time quantitative polymerase chain reaction (q-PCR) in 410 CRC patients, with mutation frequencies of KRAS, NRAS and BRAF of 47.56%, 2.93% and 4.15%, respectively. The gene mutation status and clinicopathological characteristics of 410 patients with CRC who underwent qPCR were analyzed. The KRAS and BRAF gene mutations were related to the pathological differentiation and number of metastatic lymph nodes. The BRAF gene mutation was also associated with cancer thrombosis in blood vessels. Cox regression analysis showed that there was no statistically significant difference in the overall survival (OS) between patients with KRAS, NRAS mutants and wild-type CRC patients, while the BRAF gene mutation was negatively correlated with the OS rate of CRC patients. It is suggested that the BRAF gene mutation may be an independent risk factor for the prognosis of CRC.

Personalized oncology and BRAFK601N melanoma: model development, drug discovery, and clinical correlation

PURPOSE

Mutations in BRAF are the most prominent activating mutations in melanoma and are increasingly recognized in other cancers. There is currently no accepted treatment regimen for patients with mutant BRAF^K601N melanoma, and the study of melanoma driven by BRAF mutations at the 601 locus is lacking due to a paucity of cellular model systems. Therefore, we sought to better understand the treatment and clinical approach to patients with mutant BRAF^K601N melanoma and subsequently develop a novel personalized oncology platform for rare or treatment-refractory cancers.

METHODS

We developed and characterized the first patient-derived, naturally occurring BRAF^K601N melanoma model, described herein as OHRI-MEL-13, and assessed efficacy using the Prestwick Chemical Library and select targeted therapeutics.

RESULTS

OHRI-MEL-13 exhibits loss of heterozygosity of BRAF, closely mimics the original tumor's gene expression profile, is tumorigenic in immune-deficient murine models, and is available for public accession through American Type Culture Collection. We present in silico modeling data, which illustrates the therapeutic failure of BRAF^V600E-targeted therapies in BRAF^K601N mutants. Our platform elucidated a unique role for MEK inhibition with cobimetinib, which resulted in short-term clinical success by reducing the metastatic burden.

CONCLUSION

Our model of BRAF^K601N-activated melanoma was developed, thoroughly characterized, and made available for public accession. This model served to demonstrate the feasibility of a novel personalized oncology platform that could be optimized at an institutional level for rare variant or treatment-refractory cancers. We also demonstrate the clinical utility of monotherapy MEK inhibition in a case of BRAF^K601N melanoma.

Prognostic Inflammatory Index Based on Preoperative Peripheral Blood for Predicting the Prognosis of Colorectal Cancer Patients

Simple Summary

Inflammation plays a critical role in the progression of colorectal cancer (CRC). Peripheral blood cell counts could reflect the extent of systemic inflammation and are readily available in clinical practice. The aim of our study was to construct a novel prognostic inflammatory index (PII) by integrating the blood cell counts associated with prognosis and to evaluate and validate the prognostic value of PII in two independent CRC cohorts. Multivariate Cox analyses in the training cohort of 4154 CRC patients indicated that high OS-PII (>4.27) and high DFS-PII (>4.47) were significantly associated with worse OS (HR: 1.330, p < 0.001) and worse DFS (HR: 1.366, p < 0.001), which has been validated in the external validation cohort of 5161 patients. Both OS-PII and DFS-PII have a stable prognostic performance at various follow-up times, and the nomograms based on OS-PII and DFS-PII achieved good accuracy in personalized survival prediction of patients with CRC.

Abstract

Host inflammation is a critical component of tumor progression and its status can be indicated by peripheral blood cell counts. We aimed to construct a comprehensively prognostic inflammatory index (PII) based on preoperative peripheral blood cell counts and further evaluate its prognostic value for patients with colorectal cancer (CRC). A total of 9315 patients with stage II and III CRC from training and external validation cohorts were included. The PII was constructed by integrating all the peripheral blood cell counts associated with prognosis in the training cohort. Cox analyses were performed to evaluate the association between PII and overall survival (OS) and disease-free survival (DFS). In the training cohort, multivariate Cox analyses indicated that high OS-PII (>4.27) was significantly associated with worse OS (HR: 1.330, 95% CI: 1.189–1.489, p < 0.001); and high DFS-PII (>4.47) was significantly associated with worse DFS (HR: 1.366, 95% CI: 1.206–1.548, p < 0.001). The prognostic values of both OS-PII and DFS-PII were validated in the external validation cohort. The nomograms achieved good accuracy in predicting both OS and DFS. Time-dependent ROC analyses showed that both OS-PII and DFS-PII have a stable prognostic performance at various follow-up times. The prognostic value of tumor-node-metastasis staging could be enhanced by combining it with either OS-PII or DFS-PII. We demonstrated that PIIs are independent prognostic predictors for CRC patients, and the nomograms based on PIIs can be recommended for personalized survival prediction of patients with CRC.

KRAS Codon 12 Mutation is Associated with More Aggressive Invasiveness in Synchronous Metastatic Colorectal Cancer (mCRC): Retrospective Research

Objective

To investigate the connection between mutant KRAS/NRAS/BRAF and clinicopathological characteristics in therapy-naïve synchronous metastatic colorectal cancer (mCRC) in Chinese populations when compared with all wild type (KRAS/NRAS/BRAF wild type).

Patients and Methods

A total of 200 patients with therapy-naïve synchronous mCRC (TNM stage: TanyNanyM1) were retrospectively collected as study objects. Primary tumor tissues from 200 mCRC patients were analyzed through next-generation sequencing panel to assess the mutated regions of KRAS/NRAS/BRAF.

Results

The distribution frequency of gene mutation in our study was 41% KRAS, 4% NRAS, 11.5% BRAF, 0.5% both KRAS and BRAF. Tumors with any gene mutations (any gene mutations in KRAS/NRAS/BRAF), KRAS and KRAS codon 12 mutation were more likely to be located in right-sided colon (P=0.007, P=0.008, P=0.026, respectively). For metastasis, tumors with any gene mutations, KRAS and KRAS codon 12 mutation were significantly correlated with peritoneal metastasis (P=0.019, P=0.017, P=0.014, respectively), liver-peritoneum metastases (P=0.004, P=0.003, P=0.002, respectively) and multi-organ metastases (P=0.002, P=0.008, P=0.001, respectively). Tumors with all wild type were significantly correlated with distant lymph node-only metastasis. No statistically significant differences were found between clinicopathological characteristics and KRAS codon 13 and NRAS mutations.

Conclusion

Our study suggests that clinicopathological characteristics (specifically for metastasis) are related to KRAS/NRAS/BRAF mutations in therapy-naïve synchronous mCRC population in China. We demonstrated that distant lymph node-only metastasis is visibly linked to all wild-type tumors. We found that patients with any gene mutations, KRAS mutation are more likely to carry peritoneal metastasis, liver-peritoneum metastases and multi-organ metastases than those with all wild type. After stratification, KRAS codon 12 mutation, but not codon 13 mutation, was remarkably associated with peritoneal metastasis, liver-peritoneum metastases, and multi-organ metastases compared to all wild type. These results may be useful for aiding in the prediction of prognosis and choosing the appropriate regimens for therapy.

Clinicopathologic Features and Prognosis of BRAF Mutated Colorectal Cancer Patients

Background: BRAF V600E mutation is associated with poor prognosis of colorectal cancer (CRC) patients, but the comparison of clinic-pathologic features between V600E and non-V600E mutation was not well-known in CRC patients. The aim of this study is to evaluate the clinical and pathological features, prognostic value of BRAF mutations in CRC. Methods: We conducted a retrospective study to characterize the clinical and pathological features and survival of patients with BRAF mutated CRC. Patients were classified according to BRAF status as BRAF V600E mutation and non-V600E mutations. Difference of characteristics and survival between the two groups was analyzed. Results: There was no significant difference in gender, family history, location of primary tumor, metastatic sites between patients with BRAF-V600E mutation and non-V600E mutations. Patients with V600E mutation were younger than those with non-V600E mutations (p = 0.002). Patients with BRAF V600E mutation showed a poorer outcome than those with non-V600E mutations (23.1 vs. 49.9 months, respectively, p = 0.0024). Lack of CDX2 expression was associated with worse prognosis (mOS: 9.4 m vs. not reached, respectively, p = 0.016). Status of V600E mutation did not affect the mPFS and ORR of first-line or second-line treatment. Conclusion: BRAF V600E mutation defines a distinct subgroup of CRC with worse prognosis. Lack of CDX2 expression is associated with poor OS. Status of V600E mutation did not affect the mPFS of first-line or second-line treatment.

Frequency and coexistence of KRAS, NRAS, BRAF and PIK3CA mutations and occurrence of MMR deficiency in Danish colorectal cancer patients

The MAPK signalling genes KRAS, NRAS and BRAF and the PIK3CA gene are routinely investigated for mutations in the diagnostic routine of colorectal cancer. Few studies have reported co-existing mutations in these genes with clinical relevance, while some have been previously regarded as mutually exclusive. We set to investigate the frequency and co-occurrent mutations in these targets, and the occurrence of mismatch repair deficiency (dMMR) in a large cohort of Danish colorectal cancers. 1000 colorectal tumours were sequenced as part of our diagnostic workflow for KRAS, NRAS, BRAF and PIK3CA mutations using next-generation sequencing (NGS) and analysed by immunohistochemistry (IHC) for loss of the MMR proteins, MLH1, PMS2, MSH2 and MSH6. Co-existing mutations in 12 patients (1.2%) occurred as multiple mutations in the same gene or spread across several genes (KRAS, NRAS and/or BRAF). The frequency of single mutations in the genes occurred with a frequency similar to previously reported, except for a higher frequency of BRAF mutations (18.0%). We found dMMR in 14.6% of the cases with a majority lacking expression of both MLH1 and PMS2. BRAF mutations were only present in dMMR cases involving MLH1 and/or PMS2. Our findings suggest that co-existing mutations occur, except for the hotspot BRAF V600E, which is mutually exclusive with KRAS/NRAS mutations. Therefore, instead of single gene alterations from the MAPK signalling, assessing co-occurrence of mutations within one or more of those genes should also be accounted. This may impact future oncological treatments and should be considered in the diagnostic workflow.

BRAF Mutation in Colorectal Cancers: From Prognostic Marker to Targetable Mutation

Simple Summary

Colorectal cancer with a mutation in an oncogene BRAF has paid much attention, as it comprises a population with dismal prognosis since two decades ago. A series of research since then has successfully changed this malignancy to be treatable with specific treatment. Here we thoroughly overviewed the basic, translational and clinical studies on colorectal cancer with BRAF mutation from a physician’s viewpoint. Accumulating lines of evidence suggest that intervention of the trunk cellular growth signal transduction pathway, namely EGFR-RAS-RAF-MEK-ERK pathway, is a clue to controlling this disease. However, it is not so straightforward. Recent studies unveil the diverse and plastic nature of this signal transduction pathway. We will introduce our endeavor to conquer this condition, based on newly arriving datasets, and discuss how we could open the door to future development of CRC treatment.

Abstract

The Raf murine sarcoma viral oncogene homolog B (BRAF) mutation is detected in 8–12% of metastatic colorectal cancers (mCRCs) and is strongly correlated with poor prognosis. The recent success of the BEACON CRC study and the development of targeted therapy have led to the determination of BRAF-mutated mCRCs as an independent category. For nearly two decades, a growing body of evidence has established the significance of the BRAF mutation in the development of CRC. Herein, we overview both basic and clinical data relevant to BRAF-mutated CRC, mainly focusing on the development of treatment strategies. This review is organized into eight sections, including clinicopathological features, molecular features, prognosis, the predictive value of anti-epidermal growth factor receptor (EGFR) therapy, resistant mechanisms for BRAF-targeting treatment, the heterogeneity of the BRAF mutation, future perspectives, and conclusions. A characterization of the canonical mitogen-activated protein kinase (MAPK) pathway is essential for controlling this malignancy, and the optimal combination of multiple interventions for treatments remains a point of debate.

Liver Transplantation for Colorectal and Neuroendocrine Liver Metastases and Hepatoblastoma. Working Group Report From the ILTS Transplant Oncology Consensus Conference

Liver transplantation (LT) for unresectable colorectal liver metastases has long been abandoned because of dismal prognoses. After the dark ages, advances in chemotherapy and diagnostic imaging have enabled strict patient selection, and the pioneering study from the Oslo group has contributed to the substantial progress in this field. For unresectable neuroendocrine liver metastases, LT for patients who met the Milan criteria was able to achieve excellent long-term outcomes. The guidelines further adopted in the United States and Europe were based on these criteria. For hepatoblastoma, patients with unresectable and borderline-resectable disease are considered good candidates for LT; however, the indications are yet to be defined. In the budding era of transplant oncology, it is critically important to recognize the current status and unsolved questions for each disease entity. These guidelines were developed to serve as a beacon of light for optimal patient selection for LT and set the stage for future basic and clinical studies.

Prevalence of class I-III BRAF mutations among 114,662 cancer patients in a large genomic database

IMPACT STATEMENT

These data represent the largest aggregation of BRAF mutations within a single clinical database to our knowledge. The relative proportions of both BRAF V600 mutations and non-V600 mutations are informative in all cancers and by malignancy, and can serve as a definitive gold-standard for BRAF mutation cancer incidence by malignancy. The rate of BRAF mutation in human cancer in a real-world large database is lower than previously reported likely representing testing more broadly across tumor types. The relative percentages of Class II and Class III BRAF mutations are higher than previously reported, representing almost 35% of BRAF mutations in cancer. These findings provide support for the development of effective treatments for non-V600 BRAF mutations in cancer.

Curcumin: A therapeutic strategy for colorectal cancer?

Colorectal cancer (CRC) is the second cause of cancer death worldwide. The metastatic disease is mainly treated with aggressive therapies consisting on combinations of cytotoxic chemotherapy plus anti-EGFR or anti-VEGF drugs. In spite of the improvements in clinical outcomes achieved in the last decade, these are the result of multiple new combinations using the existing therapeutic options and the introduction of regorafenib and TAS-102 in second or later lines of treatment. As immunotherapies are limited to less than 5% of CRC patients harboring tumors with deficient mismatch repair, there is an urgent need of finding new drugs to increase our patients' survival opportunities. Among all the natural products that are candidates to be used for the treatment of CRC cancer, curcumin (the golden spice) is in the spotlight. Used for centuries in the Ayurveda medicine, its demonstrated anticancer properties and low toxicity profile made it the focus of hundreds of preclinical and clinical investigations. So far we know that it can be combined with most of the aforementioned drugs in a safe and synergistic way. Regretfully, its poor bioavailability has been one of the main issues for its successful introduction in the clinic. Nevertheless, a plethora of new formulations with a huge increase in bioavailability are under study with promising results. In this review we discuss the possibility of incorporating curcumin in the treatment of CRC; specifically, we review preclinical and clinical data supporting its possible combination with current therapies as well as new formulations under clinical study. It is time for the golden spice revolution.

The Real-Life Data of BRAF Mutation on the Treatment of Colorectal Cancer: a TOG Study

PURPOSE

Colorectal cancer is the third leading diagnosis accounting for nearly 10% of all new cancers worldwide. The distinct features among BRAF mutant colorectal cancers make these tumor groups hard to treat for oncologists. The median overall survival (OS) of these types of cancers is reported to be 9 to 14 months.

METHODS

The study was declared on the Turkish Oncology Study Group Conference and approved. The patients' data was received from the centers who confirmed to participate. The BRAF-mutated patients were included in the study. The demographic features (age, gender, etc.), type of mutation, tumor localizations, histology, microsatellite instability (MSI) status, metastasis patterns chemotherapeutic agents and progression, and death times were recorded.

RESULTS

Thirty-nine patients were enrolled in the study. Sixteen patients had concurrent KRAS mutations, while 7 had NRAS mutations. Most of the patients received doublet chemotherapies in combination with anti-VEGF agents in the first and second line of the treatment. There was a significant difference in OS according to the stage which showed a decreased survival in stage IV patients at the time of diagnosis. Concurrent KRAS mutation resulted in increased OS. The median OS was 47 and 24 months favoring the KRAS mutant group. The patients whose primary tumor operated had better survival when compared with other patients. The median OS of the operated group was 47 months, while the non-operated group was 24 months. Liver metastasis was related to worse prognosis at the time of diagnosis in univariate analysis.

CONCLUSION

In our study we found a high concurrent RAS mutation ratio in a BRAF mutant patient group which was different from prior studies. The concurrent mutations resulted in a favorable outcome in terms of OS which is also different from the current knowledge. More prospective studies are needed especially BRAF-mutated patient population and especially with concurrent RAS mutations.

An amino-terminal BRAF deletion accounting for acquired resistance to RAF/EGFR inhibition in colorectal cancer

Although combination therapy with RAF and EGFR inhibitors has improved the survival outcomes of patients with BRAF-mutated colorectal cancer (CRC), acquired resistance invariably develops. The mechanisms of acquired resistance to RAF inhibitors have been largely attributed to activating mutations in RASgenes, MAP2K mutations, and amplifications in BRAF, RAS genes, and EGFR. In this report, we describe a patient with BRAF-mutated CRC who acquired an amino-terminal BRAF deletion involving the Ras-binding domain (RBD) after treatment with RAF/EGFR inhibitor therapy. Amino-terminal BRAF deletions involving the RBD are a rare mechanism of acquired resistance to RAF inhibitors, particularly in CRC for which there is only one prior report in the literature.

Genomic Alterations and Their Implications on Survival in Nonmetastatic Colorectal Cancer: Status Quo and Future Perspectives

The selection of treatment according to genomic alterations is a standard approach in metastatic colorectal cancer but is only starting to have an impact in the earlier stages of the disease. The status if genes like KRAS, BRAF, and MMR has substantial survival implications, and concerted research efforts have revolutionized treatment towards precision oncology. In contrast, a genomic-based approach has not changed the adjuvant setting after curative tumor-resection in the daily routine so far. This review focuses on the current knowledge regarding prognostic and predictive genomic biomarkers in patients with locally advanced nonmetastasized colorectal cancer. Furthermore, we provide an outlook on future challenges for a personalized adjuvant treatment approach in patients with colorectal cancer.

[BRAF V600E-mutant colorectal cancers: Where are we?]

The BRAF^V600E mutation, observed in 8 % of colorectal cancers (CRC), introduces a particular phenotype and a poor prognosis at the localized or metastatic stage. BRAF mutant CRCs are more often localized in the right colon, poorly differentiated and mucinous. They affect an older population (more often female) and are associated with a more frequent metastatic lymph node and peritoneal evolution. The BRAF^V600E mutation is associated with a sporadic microsatellite instability (MSI) status in 20 to 40% of cases. In localized colon cancer, it does not imply any modification of the adjuvant treatment. In metastatic CRC, the first action must be the systematic search for an MSI phenotype, given its frequent association with the presence of a BRAF mutation, in order to propose immunotherapy that has been demonstrated to be very effective in MSI metastatic CRC. In non-MSI CRC, a first-line trichimiotherapy associated with bevacizumab is an option to be favored in patients in good general condition but the association with an anti-EGFR can be discussed, especially when the objective is tumor response. At the same time, surgical resection must be systematically discussed in the case of resectable hepatic metastases since the presence of a BRAF^V600E mutation is not a risk factor for recurrence and that prolonged survival may be observed after surgery. In the second or third line, the triplet encorafenib, binimetinib and cetuximab, as well as the doublet encorafenib and cetuximab are superior to the association of irinotecan plus cetuximab in terms of response and survival (phase III study BEACON) and represent a new therapeutic standard. Their use on the front line is under study.

Exploring and modelling colon cancer inter-tumour heterogeneity: opportunities and challenges

Colon cancer inter-tumour heterogeneity is installed on multiple levels, ranging from (epi)genetic driver events to signalling pathway rewiring reflected by differential gene expression patterns. Although the existence of heterogeneity in colon cancer has been recognised for a longer period of time, it is sparingly incorporated as a determining factor in current clinical practice. Here we describe how unsupervised gene expression-based classification efforts, amongst which the consensus molecular subtypes (CMS), can stratify patients in biological subgroups associated with distinct disease outcome and responses to therapy. We will discuss what is needed to extend these subtyping efforts to the clinic and we will argue that preclinical models recapitulate CMS subtypes and can be of vital use to increase our understanding of treatment response and resistance and to discover novel targets for therapy.

NCCN Guidelines Insights: Rectal Cancer, Version 6.2020

The NCCN Guidelines for Rectal Cancer provide recommendations for the diagnosis, evaluation, treatment, and follow-up of patients with rectal cancer. These NCCN Guidelines Insights summarize the panel discussion behind recent important updates to the guidelines. These updates include clarifying the definition of rectum and differentiating the rectum from the sigmoid colon; the total neoadjuvant therapy approach for localized rectal cancer; and biomarker-targeted therapy for metastatic colorectal cancer, with a focus on new treatment options for patients with BRAF V600E- or HER2 amplification-positive disease.

TRF2 and VEGF-A: an unknown relationship with prognostic impact on survival of colorectal cancer patients

BACKGROUND

Colorectal cancer is one of most common tumors in developed countries and, despite improvements in treatment and diagnosis, mortality rate of patients remains high, evidencing the urgent need of novel biomarkers to properly identify colorectal cancer high-risk patients that would benefit of specific treatments. Recent works have demonstrated that the telomeric protein TRF2 is over-expressed in colorectal cancer and it promotes tumor formation and progression through extra-telomeric functions. Moreover, we and other groups evidenced, both in vitro on established cell lines and in vivo on tumor bearing mice, that TRF2 regulates the vascularization mediated by VEGF-A. In the present paper, our data evidence a tight correlation between TRF2 and VEGF-A with prognostic relevance in colorectal cancer patients.

METHODS

For this study we sampled 185 colorectal cancer patients surgically treated and diagnosed at the Regina Elena National Cancer Institute of Rome and investigated the association between the survival outcome and the levels of VEGF-A and TRF2.

RESULTS

Tissue microarray immunohistochemical analyses revealed that TRF2 positively correlates with VEGF-A expression in our cohort of patients. Moreover, analysis of patients' survival, confirmed in a larger dataset of patients from TCGA, demonstrated that co-expression of TRF2 and VEGF-A correlate with a poor clinical outcome in stage I-III colorectal cancer patients, regardless the mutational state of driver oncogenes.

CONCLUSIONS

Our results permitted to identify the positive correlation between high levels of TRF2 and VEGF-A as a novel prognostic biomarker for identifying the subset of high-risk colorectal cancer patients that could benefit of specific therapeutic regimens.

BRAF and KRAS mutations in metastatic colorectal cancer: future perspectives for personalized therapy

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers worldwide and 30% of patients with CRC experience metastasis. Patients with metastatic colorectal cancer (mCRC) have a 5-year overall survival rate of <10%. V-raf murine sarcoma viral oncogene homolog B1 (BRAF) and V-Ki-ras2 Kirsten ratsarcoma viral oncogene homolog (KRAS) mutations are mostly studied in mCRC, as clinical trials found that first-line chemotherapy with anti-epidermal growth factor receptor agent confers limited efficacy for mCRC. Treatment decisions for early-stage mCRC do not consider BRAF or KRAS mutations, given the dramatically poor prognosis conferred by these mutations in clinical trials. Thus, it is necessary to identify patients with mCRC harboring BRAF or KRAS mutations to formulate rational therapeutic strategies to improve prognosis and survival. BRAF and KRAS mutations occur in ∼10% and ∼44% of patients with mCRC, respectively. Although the survival rate of patients with mCRC has improved in recent years, the response and prognosis of patients with the aforementioned mutations are still poor. There is a substantial unmet need for prospective personalized therapies for patients with BRAF- or KRAS-mutant mCRC. In this review, we focus on BRAF and KRAS mutations to understand the mechanisms underlying resistance and improving the response rate, outcomes, and prognosis of patients with mCRC bearing these mutations and to discuss prospective personalized therapies for BRAF- and KRAS-mutant mCRC.

Update on optimal treatment for metastatic colorectal cancer from the AGITG expert meeting: ESMO congress 2019

Introduction: Outcomes in metastatic colorectal cancer are improving, due to the tailoring of therapy enabled by better understanding of clinical behavior according to molecular subtype.Areas covered: A review of the literature and recent conference presentations was undertaken on the topic of systemic treatment of metastatic colorectal cancer. This review summarizes expert discussion of the current evidence for therapies in metastatic colorectal cancer (mCRC) based on molecular subgrouping.Expert opinion: EGFR-targeted and VEGF-targeted antibodies are now routinely incorporated into treatment strategies for mCRC. EGFR-targeted antibodies are restricted to patients with extended RAS wild-type profiles, with evidence that they should be further restricted to patients with left-sided tumors. Clinically distinct treatment pathways based on tumor RAS, BRAF, HER2 and MMR status, are now clinically applicable. Evidence suggests therapy for additional subgroups will soon be defined; the most advanced being for patients with KRAS G12 C mutation and gene TRK fusion defects.

RNF43 mutation is associated with aggressive tumor biology along with BRAF V600E mutation in right-sided colorectal cancer

Right-sided colorectal cancer (RCRC) demonstrates worse survival outcome compared with left-sided CRC (LCRC). Recently, the importance of RNF43 mutation and BRAF V600E mutation has been reported in the serrated neoplasia pathway, which is one of the precancerous lesions in RCRC. It was hypothesized that the clinical significance of RNF43 mutation differs according to primary tumor sidedness. To test this hypothesis, the clinicopathological characteristics and survival outcome of patients with RNF43 mutation in RCRC and LCRC were investigated. Stage I–IV CRC patients (n=201) were analyzed. Genetic alterations including RNF43 using a 415-gene panel were investigated. Clinicopathological characteristics between RNF43 wild-type and RNF43 mutant-type were analyzed. Moreover, RNF43 mutant-type was classified according to primary tumor sidedness, i.e., right-sided RNF43 mutant-type or left-sided RNF43 mutant-type, and the clinicopathological characteristics between the two groups were compared. RNF43 mutational prevalence, spectrum and frequency between our cohort and TCGA samples were compared. RNF43 mutation was observed in 27 out of 201 patients (13%). Multivariate analysis revealed that age (≥65), absence of venous invasion, and BRAF V600E mutation were independently associated with RNF43 mutation. Among the 27 patients with RNF43 mutation, 12 patients were right-sided RNF43 mutant-type and 15 left-sided RNF43 mutant-type. Right-sided RNF43 mutant-type was significantly associated with histopathological grade 3, presence of lymphatic invasion, APC wild, BRAF V600E mutation, microsatellite instability-high (MSI-H), and RNF43 nonsense/frameshift mutation compared with left-sided RNF43 mutant-type. Similarly, RNF43 nonsense/frameshift mutations were more frequently observed in RCRC compared with LCRC in the TCGA cohort (P=0.042). Right-sided RNF43 mutant-type exhibited significantly worse overall survival than RNF43 wild-type and left-sided RNF43 mutant-type (P=0.001 and P=0.023, respectively) in stage IV disease. RNF43 mutation may be a distinct molecular subtype which is associated with aggressive tumor biology along with BRAF V600E mutation in RCRC.

Successful treatment of metastatic colorectal cancer with synchronous BRAF V600E mutation and dMMR with BGB-A317

Metastatic colorectal cancer with BRAF mutation is a type of highly invasive malignant tumor with poor prognosis and few treatment options. Here, we report a case of a BRAF-mutant and DNA mismatch-repair deficiency colorectal cancer patient with postoperative recurrence as well as abdominal cavity and pelvic metastasis, whose condition was relieved continuously after treatment with a new anti-PD-1 antibody, BGB-A317.

Colorectal cancer genomic biomarkers in the clinical management of patients with metastatic colorectal carcinoma

Colorectal carcinoma (CRC) is an heterogeneous disease in which different genetic alterations play a role in its pathogenesis and progression and offer potential for therapeutic intervention. The research on predictive biomarkers in metastatic CRC (mCRC) mainly focused on the identification of biomarkers of response or resistance to anti-epidermal growth factor receptor monoclonal antibodies. In this respect, international guidelines suggest testing mCRC patients only for KRAS, NRAS and BRAF mutations and for microsatellite instability. However, the use of novel testing methods is raising relevant issue related to these biomarkers, such as the presence of sub-clonal RAS mutations or the clinical interpretation of rare no-V600 BRAF variants. In addition, a number of novel biomarkers is emerging from recent studies including amplification of ERBB2, mutations in ERBB2, MAP2K1 and NF1 and rearrangements of ALK, ROS1, NTRK and RET. Mutations in POLE and the levels of tumor mutation burden also appear as possible biomarkers of response to immunotherapy in CRC. Finally, the consensus molecular subtypes classification of CRC based on gene expression profiling has prognostic and predictive implications. Integration of all these information will be likely necessary in the next future in order to improve precision/personalized medicine in mCRC patients.

Shanghai international consensus on diagnosis and comprehensive treatment of colorectal liver metastases (version 2019)

The liver is the most common anatomical site for hematogenous metastases from colorectal cancer. Therefore effective treatment of liver metastases is one of the most challenging elements in the management of colorectal cancer. However, there is rare available clinical consensus or guideline only focusing on colorectal liver metastases. After six rounds of discussion by 195 clinical experts of the Shanghai International Consensus Expert Group on Colorectal Liver Metastases (SINCE) from 29 countries or regions, the Shanghai Consensus has been finally completed, based on current research and expert experience. The consensus emphasized the principle of multidisciplinary team, provided detailed diagnosis approaches, and guided precise local and systemic treatments. This Shanghai Consensus might be of great significance to standardized diagnosis and treatment of colorectal liver metastases all over the world.

A Rare Case of Non-Small Cell Lung Cancer with BRAF V600E Gene: Case Report and Literature Review

Non-small cell lung cancer is one of the leading causes of mortality in the United States. The BRAF mutation, which has been associated with malignant melanoma, has been documented in only 3.5-5% of the non-small cell lung cancer (NSCLC) patient population.The involvement of the BRAF mutation in NSCLC and the treatment for tumors with such mutations is still an evolving topic of interest, which is why more in depth information is warranted. We present a rare case of stage IV non-small cell lung adenocarcinoma, who presented first with a complicated pericardial effusion with evidence of malignant effusion. He had genetic testing done, revealing he had a positive BRAF V600E mutation. He was put on multiple chemotherapy regimens, but was most responsive to Vemurafenib. This case will shed light into the importance of the BRAF V600E gene and its importance in NSCLC for better prognosis value. 

BRAF mutant colorectal cancer: ErbB2 expression levels as predictive factor for the response to combined BRAF/ErbB inhibitors

BACKGROUND

Colorectal cancer (CRC) is a heterogeneous disease with a complex biology and a wide number of altered genes such as BRAF, KRAS and PIK3CA. Advances with new-targeted therapies have been achieved and available treating options have prolonged patient's survival. However, BRAF-mutated CRC patients remain unresponsive to available therapies with RAF inhibitors (RAFi) alone or combined with ErbB inhibitors (ErbBi). These unmet needs require further exploitation of oncogenic signaling in order to set up individualized treatments.

METHODS

To this end, we tested the efficacy of single agent or combined treatments using the BRAFi, vemurafenib and two different ErbBi: panitumumab and afatinib in CRC cells characterized by different molecular phenotypes.

RESULTS

Combination strategies with BRAFi and ErbBi achieved a better response in BRAFV600E mutated cells expressing high levels of ErbB2.

CONCLUSIONS

Our findings support the importance of ErbB2 evaluation in BRAF-mutated CRC patients and its role as a positive predictor factor of response to BRAFi/ErbBi combination.

Repeat Hepatectomy After Major Hepatectomy for Colorectal Liver Metastases

OBJECTIVE

This study assessed predictors of survival after repeat hepatectomy and the feasibility of a repeat hepatectomy after a major hepatectomy in the patients with colorectal liver metastases (CLM).

BACKGROUND

More than half of all patients who receive a curative initial hepatectomy for CLM develop hepatic recurrence, and aggressive indications for a repeat hepatectomy can improve the outcome in selected patients. However, the feasibility of repeat hepatectomy after major hepatectomy remains uncertain, and optimal selection criteria for repeat hepatectomy have not yet been established.

METHODS

Data were collected retrospectively on 296 CLM patients who underwent an initial curative hepatectomy between 2007 and 2017 at our institution. The postoperative outcomes of patients undergoing a repeat hepatectomy after major hepatectomy were assessed, and independent predictors of survival were investigated.

RESULTS

After a median follow-up period of 32 months, 247 patients (83%) developed disease recurrence and 122 patients (49%) underwent repeat hepatectomy. The 5-year overall survival (OS) was significantly higher in patients who underwent a repeat hepatectomy than in those who did not receive repeat hepatectomy (51% vs. 19%, respectively; P < 0.001). In a multivariate analysis, an extrahepatic lesion at the time of the repeat hepatectomy (HR, 2.49; P = 0.001) and 5 or more liver tumors at the time of recurrence (HR, 1.88; P = 0.04) remained as independent factors negatively affecting OS after repeat hepatectomy. The type of operative procedure and the intraoperative and postoperative factors at the time of the initial hepatectomy did not have any significant influence on the OS after repeat hepatectomy. No significant difference in OS was found between patients who received repeat hepatectomy after major hepatectomy (n = 43) and those after non-major hepatectomy (n = 79).

CONCLUSIONS

The operative procedure and the liver tumor status at the time of the initial hepatectomy have little impact on the indications for a repeat hepatectomy for recurrent CLM. Repeat hepatectomy is feasible even if major hepatectomy was initially performed.

The heterogeneous clinical and pathological landscapes of metastatic Braf-mutated colorectal cancer

Colorectal cancer (CRC) is a complex and molecularly heterogeneous disease representing one of the most frequent causes of cancer-related death worldwide. About 8–15% of CRCs harbor a mutation in BRAF gene, a proto-oncogene involved in cell proliferation, differentiation and survival through the MAPK signaling cascade. The acquisition of BRAF mutation is an early event in the “serrated” CRC carcinogenetic pathway and is associated with specific and aggressive clinico-pathological and molecular features. Despite that the presence of BRAF mutation is a well-recognized negative prognostic biomarker in metastatic CRC (mCRC), a great heterogeneity in survival outcome characterizes these patients, due to the complex, and still not completely fully elucidated, interactions between the clinical, genetic and epigenetic landscape of BRAF mutations. Because of the great aggressiveness of BRAF-mutated mCRCs, only 60% of patients can receive a second-line chemotherapy; so intensive combined and tailored first-line approach could be a potentially effective strategy, but to minimize the selective pressure of resistant clones and to reduce side effects, a better stratification of patients bearing BRAF mutations is needed.

ERK/MAPK signalling pathway and tumorigenesis

Mitogen-activated protein kinase (MAPK) cascades are key signalling pathways that regulate a wide variety of cellular processes, including proliferation, differentiation, apoptosis and stress responses. The MAPK pathway includes three main kinases, MAPK kinase kinase, MAPK kinase and MAPK, which activate and phosphorylate downstream proteins. The extracellular signal-regulated kinases ERK1 and ERK2 are evolutionarily conserved, ubiquitous serine-threonine kinases that regulate cellular signalling under both normal and pathological conditions. ERK expression is critical for development and their hyperactivation plays a major role in cancer development and progression. The Ras/Raf/MAPK (MEK)/ERK pathway is the most important signalling cascade among all MAPK signal transduction pathways, and plays a crucial role in the survival and development of tumour cells. The present review discusses recent studies on Ras and ERK pathway members. With respect to processes downstream of ERK activation, the role of ERK in tumour proliferation, invasion and metastasis is highlighted, and the role of the ERK/MAPK signalling pathway in tumour extracellular matrix degradation and tumour angiogenesis is emphasised.

KRAS and BRAF Mutations as Prognostic and Predictive Biomarkers for Standard Chemotherapy Response in Metastatic Colorectal Cancer: A Single Institutional Study

KRAS mutation is a confirmed predictive biomarker for anti-EGFR monoclonal antibody therapy response for metastatic colorectal cancer. However, its prognosis impact and the predictive potential for first-line standard chemotherapy remains unclear. On the other hand, V600E mutation is the most frequent and studied mutation in the BRAF gene, and it has been associated with a poor outcome of patients and a low response to anti-EGFR treatment. Thus, the aim of this study is to evaluate the role of KRAS and BRAF mutations as prognosis factors and predictive biomarkers for 1st line standard chemotherapy in metastatic colorectal cancer. KRAS mutations and BRAF V600E mutations exhibited a poor outcome (p = 0.021 and p < 0.0001, respectively). Cox multivariate analysis showed that the presence of liver metastasis (HR = 1.595; 95% CI: 1.086–2.343; p = 0.017), KRAS mutation (HR = 1.643; 95% CI: 1.110–2.431; p = 0.013) and BRAF V600E mutation (HR = 5.861; 95% CI: 2.531–13.570; p < 0.0001) were statistically significant co-variables for progression-free survival. Interestingly, patients with KRAS mutations were associated with a poor response to first line standard chemotherapy (p = 0.008). In contrast, the BRAF V600E mutation did not have any impact on the first line standard chemotherapy response (p = 0.540). Therefore, in the present study, we provide new insight on the role of KRAS and BRAF, not only as prognosis biomarkers, but also as first line standard chemotherapy response biomarkers in metastatic colorectal cancer.

Targeting BRAF-Mutant Biliary Tract Cancer: Recent Advances and Future Challenges

BACKGROUND

Biliary tract cancers (BTCs) represent a heterogeneous group of aggressive solid tumors with limited therapeutic options, and include gallbladder cancer (GBC), ampulla of Vater cancer (AVC), intrahepatic cholangiocarcinoma (iCCA) and extrahepatic cholangiocarcinoma (eCCA).

METHODS & RESULTS

In the current review, we will discuss recent results of clinical trials testing targeted therapies in BRAF-mutant BTCs, with a particular focus on the recently published Phase II ROAR trial and ongoing active and recruiting clinical trials.

CONCLUSIONS

Although the extended use of molecular profiling has paved the way toward a new era in BTC management, targeted therapies are limited to iCCA so far, and the prognosis of patients with metastatic disease has substantially not changed in the last decade. In this discouraging scenario, BRAF inhibition is currently emerging as a novel treatment option in patients harboring BRAF mutations.

Biomarker-guided therapy for colorectal cancer: strength in complexity

The number of molecularly stratified treatment options available to patients with colorectal cancer (CRC) is increasing, with a parallel rise in the use of biomarkers to guide prognostication and treatment decision-making. The increase in both the number of biomarkers and their use has resulted in a progressively complex situation, evident both from the extensive interactions between biomarkers and from their sometimes complex associations with patient prognosis and treatment benefit. Current and emerging biomarkers also reflect the genomic complexity of CRC, and include a wide range of aberrations such as point mutations, amplifications, fusions and hypermutator phenotypes, in addition to global gene expression subtypes. In this Review, we provide an overview of current and emerging clinically relevant biomarkers and their role in the management of patients with CRC, illustrating the intricacies of biomarker interactions and the growing treatment opportunities created by the availability of comprehensive molecular profiling.

Circulating Tumour Cells, Circulating Tumour DNA and Circulating Tumour miRNA in Blood Assays in the Different Steps of Colorectal Cancer Management, a Review of the Evidence in 2019

Despite many advances in the diagnosis and treatment of colorectal cancer (CRC), its incidence and mortality rates continue to make an impact worldwide and in some countries rates are mounting. Over the past decade, liquid biopsies have been the object of fundamental and clinical research with regard to the different steps of CRC patient care such as screening, diagnosis, prognosis, follow-up, and therapeutic response. They are attractive because they are considered to encompass both the cellular and molecular heterogeneity of tumours. They are easily accessible and can be applied to large-scale settings despite the cost. However, liquid biopsies face drawbacks in detection regardless of whether we are testing for circulating tumour cells (CTCs), circulating tumour DNA (ctDNA), or miRNA. This review highlights the different advantages and disadvantages of each type of blood-based biopsy and underlines which specific one may be the most useful and informative for each step of CRC patient care.

Characteristics of BRAFV600E Mutant, Deficient Mismatch Repair/Proficient Mismatch Repair, Metastatic Colorectal Cancer: A Multicenter Series of 287 Patients

BACKGROUND

BRAFV600E mutations occurring in about 10% of metastatic colorectal cancers (mCRCs) are usually associated with a poor outcome. However, their prognostic factors are unknown.

MATERIALS AND METHODS

We built a multicenter clinico-biological database gathering data from patients with BRAFV600E -mutant mCRC treated in one of the 16 French centers from 2006 to 2017. The primary endpoint was to identify prognostic factors using a Cox model.

RESULTS

We included 287 patients (median age, 67 years [28-95]; female, 57%). Their median overall survival was 20.8 months (95% confidence interval [CI], 17.97-27.04), and median progression-free survival in the first-line setting was 4.34 months (95% CI, 3.81-5.03). Chemotherapy regimen and biological agents (antiangiogenic or anti-epidermal growth factor receptor) were not associated with overall and progression-free survival. Stage IV disease (synchronous metastases) and absence of curative-intent surgery were statistically associated with poor overall survival. Among the 194 patients with mismatch repair (MMR) status available, overall survival was significantly longer in patients with deficient MMR tumors compared with those with proficient MMR tumors (adjusted hazard ratio = 0.56; p = .009).

CONCLUSION

Despite that BRAFV600E -mutant mCRCs are associated with poor overall and progression-free-survival, patients with deficient MMR tumors and/or resectable disease experienced a longer survival. These results highlight the importance of MMR testing and resectability discussion in patients with BRAFV600E mCRC in day-to-day practice.

IMPLICATIONS FOR PRACTICE

Mismatch repair (MMR) testing and resectability discussion in patients with BRAFV600E metastatic colorectal cancer (mCRC) should be performed in day-to-day practice to steer treatment decision making in patients with BRAFV600E -mutant mCRC.

VEGF-A and ICAM-1 Gene Polymorphisms as Predictors of Clinical Outcome to First-Line Bevacizumab-Based Treatment in Metastatic Colorectal Cancer

Bevacizumab is used to treat metastatic colorectal cancer (mCRC). However, there are still no available predictors of clinical outcomes. We investigated selected single nucleotide polymorphisms (SNPs) in the genes involved in VEGF-dependent and -independent angiogenesis pathways and other major intracellular signaling pathways involved in the pathogenesis of mCRC as an attempt to find predictors of clinical outcome. Forty-six patients treated with first-line bevacizumab-based chemotherapy were included in this study with a 5 year follow up. Genomic DNA was isolated from whole blood for the analysis of VEGF-A (rs2010963, 1570360, rs699947), ICAM-1 (rs5498, rs1799969) SNPs and from tumor tissue for the detection of genomic variants in KRAS, NRAS, BRAF genes. PCR and next generation sequencing were used for the analysis. The endpoints of the study were progression-free survival (PFS) and overall survival (OS). The VEGF-A rs699947 A/A allele was associated with increased PFS (p = 0.006) and OS (p = 0.043). The ICAM-1 rs1799969 G/A allele was associated with prolonged OS (p = 0.036). Finally, BRAF wild type was associated with increased OS (p = 0.027). We identified VEGF-A and ICAM-1 variants in angiogenesis and other major intracellular signaling pathways, such as BRAF, that can predict clinical outcome upon bevacizumab administration. These identified biomarkers could be used to select patients with mCRC who may achieve long-term responses and benefit from bevacizumab-based therapies.