BRAFV600E Mutant Colorectal Cancer Subtypes Based on Gene Expression

Decoding colorectal cancer targeted therapy: a bibliometric journey of the last decade (2015-2024)

Colorectal cancer remains one of the most commonly diagnosed cancers globally, with a significant impact on public health. Targeted therapies have revolutionized the treatment landscape for colorectal cancer by offering increased specificity and reduced systemic toxicity compared to conventional chemotherapy. This study provides a comprehensive bibliometric analysis of global research on targeted therapy for colorectal cancer, focusing on publications from 2015 to 2024. A total of 3213 publications were retrieved from the Web of Science Core Collection and analyzed using bibliometric tools to construct knowledge maps and visualize research trends. The regression analysis shows a strong upward trend in publications from 2015 to 2024 (P < 0.001, R2 = 0.889). China leads in publication output, with the University of Texas MD Anderson Cancer Center contributing the highest number of studies. Tabernero and Kopetz are the core authors in the field. Research in this domain has primarily concentrated on the development and clinical assessment of drugs targeting the EGFR, RAS, VEGF, and BRAF signaling pathways, as well as investigating the pathogenesis, drug resistance, and metastatic mechanisms of colorectal cancer. Current advancements emphasize Artificial Intelligence-driven multi-omics integration, the creation of novel therapeutics targeting established molecular pathways, and the execution of global clinical trials to validate personalized treatment strategies.

BRAFV600E mutant metastatic colorectal cancer: Current advances in personalized treatment and future perspectives

Detection of the BRAF V600E mutation has important genetic, prognostic, and therapeutic implications for patients with metastatic colorectal cancer (mCRC), identifying a subgroup of patients who derive modest benefit from standard treatments and have extremely poor prognosis. The evolution of molecular profiling and the implementation of next generation sequencing in the evaluation of a patient with BRAF-mutated mCRC has currently led to the discovery of actionable alterations. Targeting multiple pathways of resistance in BRAF-mutated mCRC may be the most efficacious route. Then, over a short period of time, the treatment landscape BRAF-mutated mCRC patients has shifted dramatically. Finally, novel treatment strategies are available. This review will discuss on currently approved treatments for BRAF V600E mutated mCRC and will try and portray the changing landscape in this setting in the era of targeted molecular therapy.

Extracellular vesicle-mediated gene therapy targets BRAFV600E-mutant colorectal cancer by inhibiting the MEK1/2-ERK1/2 pathway

BACKGROUND

Patients with colorectal cancer (CRC) harboring BRAF mutation have a poor prognosis. The median survival time for patients with advanced BRAFV600E-mutant CRC is only approximately one year. Owing to the insensitivity to standard chemotherapy, there are still no effective and highly specific treatment strategies available in clinical practice for CRC patients with BRAF mutation. Therefore, targeting the BRAFV600E mutation site, researching and exploring novel targeted therapies are essential to improve the survival rate of patients with this CRC subtype.

AIM

This study aims to develop a precise therapeutic system for BRAFV600E CRC, based on the carrier properties of extracellular vesicles (EVs) and gene therapy targeting BRAFV600E.

METHOD

We first obtained engineered cells capable of stably producing EVs loaded with BRAFV600E nucleic acid drugs (siBRAFV600E). Next, BRAFV600E-mutant and wild-type CRC cell lines, as well as corresponding subcutaneous and metastasis models, were used to evaluate the therapeutic efficacy of EVs-siBRAFV600E and explored the mechanism. Notably, patient-derived xenograft (PDX) models, which share the same molecular characteristics, pathological features, and heterogeneity as patients do, were utilized to further explore the therapeutic efficacy and mechanisms.

RESULT

EVs-siBRAFV600E specifically inhibited BRAFV600E CRC but didn't affect BRAF wild-type CRC in vitro and vivo. EVs-siBRAFV600E exerts its therapeutic effect by regulating the MEK1/2-ERK1/2 pathway, and it has demonstrated excellent therapeutic efficacy in PDX models.

CONCLUSION

The therapeutic EVs we constructed are effective and specific for the BRAFV600E-mutant CRC. This study provides a novel strategy for the treatment of CRC patients with BRAFV600E mutation.

Identification of T cell dysfunction molecular subtypes and exploration of potential immunotherapy targets in BRAF V600E-mutant colorectal cancer

BACKGROUND

Immunotherapy is an effective treatment for BRAF V600E-mutant colorectal cancer, but currently, only a few benefit from it. Therefore, exploring new immunotherapy strategies is essential.

METHODS

We obtained RNA sequencing data and clinical information of colorectal cancer patients from the TCGA and GEO databases. The impact of the BRAF V600E mutation on tumor microenvironment characteristics, gene expression, and signaling pathways was evaluated using bioinformatics approaches. Weighted gene co-expression network analysis (WGCNA) were used to identify core genes associated with T cell dysfunction. Consensus clustering was applied for subtype construction. Least Absolute Shrinkage and Selection Operator (LASSO) and Random Forest (RF) algorithms were employed to filter potential immunotherapy targets.

RESULTS

We found that BRAF V600E mutation has a complex impact on the immune profile of colorectal cancer. It increases immune cell infiltration and activates immune-related signaling pathways, yet it also severely restricts T cell function. We subsequently identified 39 core genes associated with T cell dysfunction and constructed subtypes of BRAF V600E colorectal cancer based on their expression profiles. Significant heterogeneity was observed between these subtypes in immune signaling pathway activity, immune infiltration patterns, immune phenotype scores, and mechanisms of resistance to immunotherapy. Ultimately, using machine learning algorithms and bioinformatics validation, we identified IDO1 as a potential immunotherapy targets for BRAF V600E-mutant colorectal cancer.

CONCLUSION

This study constructed novel T cell dysfunction molecular subtypes for BRAF V600E-mutant colorectal cancer and identified IDO1 as a potential immunotherapy target, providing a new strategy for immunotherapy.

Expert consensus on the optimal management of BRAFV600E-mutant metastatic colorectal cancer in the Asia-Pacific region

The burden of colorectal cancer (CRC) is high in the Asia-Pacific region, and several countries in this region have among the highest and/or fastest growing rates of CRC in the world. A significant proportion of patients will present with or develop metastatic CRC (mCRC), and BRAFV600E-mutant mCRC represents a particularly aggressive phenotype that is less responsive to standard chemotherapies. In light of recent therapeutic advances, an Asia-Pacific expert consensus panel was convened to develop evidence-based recommendations for the diagnosis, treatment, and management of patients with BRAFV600E-mutant mCRC. The expert panel comprised nine medical oncologists from Australia, Hong Kong, Singapore, and Taiwan (the authors), who met to review current literature and develop eight consensus statements that describe the optimal management of BRAFV600E-mutant mCRC in the Asia-Pacific region. As agreed by the expert panel, the consensus statements recommend molecular testing at diagnosis to guide individualized treatment decisions, propose optimal treatment pathways according to microsatellite stability status, advocate for more frequent monitoring of BRAFV600E-mutant mCRC, and discuss local treatment strategies for oligometastatic disease. Together, these expert consensus statements are intended to optimize treatment and improve outcomes for patients with BRAFV600E-mutant mCRC in the Asia-Pacific region.

Detecting BRAF mutations in colorectal cancer in clinical practice: An Italian experts' position paper

BRAF p.V600E exon 15 hotspot mutation can identify a molecular subgroup of metastatic colorectal cancer (mCRC) patients exhibiting poor prognosis under the conventional chemotherapy regimen. Recently, the chemotherapy-free combination of encorafenib and cetuximab has been approved as the standard of care for previously treated BRAF p.V600E mCRC patients, and genomic testing for BRAF mutations at the time of mCRC diagnosis is currently recommended. In clinical practice, BRAF mutation testing strategies are dramatically impacted by a lack of harmonization and standardization, both in the pre-analytical and analytical phases, which can result in BRAF-mutated patients not receiving the most appropriate therapy at recurrence. This paper proposes nine statements providing practical and concise advice on BRAF mutation testing in CRC, derived from collegial discussion and analysis of a multidisciplinary team of experts, including referral Italian oncologists and pathologists. The statements overview pivotal aspects implied in the detection, treatment and management of BRAF-mutated patients and have been drafted to represent a valuable tool for healthcare professionals committed to mCRC patient management. In addition, they represent a platform for implementing diagnostic-therapeutic workflows that can adapt to the variability of local resources while respecting the high-quality standards required by modern precision oncology.

A Narrative Review of the Role of Immunotherapy in Metastatic Carcinoma of the Colon Harboring a BRAF Mutation

Patients affected by metastatic carcinoma of the colon/rectum (mCRC) harboring mutations in the BRAF gene (MBRAF) respond poorly to conventional therapy and have a prognosis worse than that of patients without mutations. Despite the promising outcomes of targeted therapy utilizing multi-targeted inhibition of the mitogen-activated protein kinase (MAPK) signaling system, the therapeutic efficacy, especially for the microsatellite stable/DNA proficient mismatch repair (MSS/PMMR) subtype, remains inadequate. Patients with MBRAF/mCRC and high microsatellite instability or DNA deficient mismatch repair (MSI-H/DMMR) exhibit a substantial tumor mutation burden, suggesting a high probability of response to immunotherapy. It is widely acknowledged that MSS/pMMR/mCRC is an immunologically "cold" malignancy that exhibits resistance to immunotherapy. The integration of targeted therapy and immunotherapy may enhance clinical outcomes in patients with MBRAF/mCRC. Efforts to enhance outcomes are exclusively focused on MSS/DMMR-BRAF mutant cancers, which constitute the largest proportion. This review evaluates the clinical efficacy and advancement of novel immune checkpoint blockade therapies for MSI-H/DMMR and MSS/PMMR BRAF mutant mCRC. We examine potential indicators in the tumor immune milieu for forecasting immunotherapeutic response in BRAF mutant mCRC.

VIC Regimen (Vemurafenib/Irinotecan/Cetuximab) Versus Bevacizumab Plus Chemotherapy as First-Line Treatment for BRAF V600E-Mutated Unresectable or Metastatic Colorectal Cancer in Asian Patients: A Prospective Cohort Study

BACKGROUND

Colorectal cancers (CRC) with BRAF V600E mutation exhibit limited chemotherapy response and a poor prognosis. Safety and efficacy of the VIC (Vemurafenib/Irinotecan/Cetuximab) regimen in the first-line setting for patients with BRAF V600E-mutated CRC remain undetermined.

METHODS

In the prospective cohort study, the untreated, BRAF V600E-mutated, unresectable or metastatic CRC patients were enrolled. The VIC regimen and bevacizumab plus chemotherapy were compared in the first-line setting. The objective response rate (ORR), disease control rate (DCR), conversion resection rate, progression-free survival (PFS), and overall survival (OS) were evaluated.

RESULTS

In the intent-to-treat analysis, 38 patients received VIC regimen and 40 received bevacizumab plus chemotherapy. The ORR and DCR in the VIC group were significantly higher than in the bevacizumab-therapy group (ORR: 63.2% vs. 37.5%, P = .025; DCR: 94.7% vs. 75.0%, P = .019). The VIC regimen significantly outperformed bevacizumab plus chemotherapy in both PFS (11.9 vs. 7.7 months; hazard ratio [HR] = 0.51, 95% CI, 0.30-0.87; P = .010) and OS (25.3 vs. 14.6 months; HR = 0.43, 95% CI, 0.22-0.82; P = .011). In the VIC group, the conversion resection rate for liver metastases was 34.8% (8 of 23 patients), and for unresectable local CRC it was 54.5% (6 of 11 patients). The adverse events rates of Grade 3 to 4 were 34.2% and 32.5% for the VIC regimen and bevacizumab plus chemotherapy respectively.

CONCLUSIONS

Among Asian patients with BRAF V600E-mutated CRC, the VIC regimen showed favorable outcomes compared to bevacizumab plus chemotherapy in terms of tumor response and oncological survival, with a tolerable and manageable toxicity profile in the first-line setting.

Colorectal cancer with BRAF V600E mutation: Trends in immune checkpoint inhibitor treatment

Colorectal cancer (CRC) with BRAF V600E mutation presents a formidable scientific and clinical challenge due to its aggressive nature and poor response to standard therapeutic approaches. BRAF V600E mutation-induced conspicuous activation of the MAPK pathway contributes to the relentless tumor progression. Nevertheless, the efficacy of multi-targeted MAPK pathway inhibition remains suboptimal in clinical practice. Patients with high microsatellite instability (MSI-H) have shown favorable results with immune checkpoint inhibitors (ICIs). The combination of the MAPK pathway inhibition with ICIs has recently emerged as a promising regimen to improve clinical outcomes in the microsatellite stable (MSS) subgroup of BRAF V600E-mutant metastatic CRC patients. In this review, we elucidate the unique tumor biology of BRAF V600E-mutant CRC, with a particular focus on the immune features underlying the rationale for ICI treatments in the MSI-H and MSS subpopulations, then highlight the trends in clinical trials of the ICI therapy for BRAF V600E-mutant metastatic CRC.

Molecular profiling of BRAF-V600E-mutant metastatic colorectal cancer in the phase 3 BEACON CRC trial

The BEACON CRC study demonstrated that encorafenib (Enco)+cetuximab (Cetux)±binimetinib (Bini) significantly improved overall survival (OS) versus Cetux + chemotherapy in previously treated patients with BRAF-V600E-mutant mCRC, providing the basis for the approval of the Enco+Cetux regimen in the United States and the European Union. A greater understanding of biomarkers predictive of response to Enco+Cetux±Bini treatment is of clinical relevance. In this prespecified, exploratory biomarker analysis of the BEACON CRC study, we characterize genomic and transcriptomic correlates of clinical outcomes and acquired resistance mechanisms through integrated clinical and molecular analysis, including whole-exome and -transcriptome tissue sequencing and circulating tumor DNA genomic profiling. Tumors with higher immune signatures showed a trend towards increased OS benefit with Enco+Bini+Cetux. RAS, MAP2K1 and MET alterations were most commonly acquired with Enco+Cetux±Bini, and more frequent in patients with a high baseline cell-cycle gene signature; baseline TP53 mutation was associated with acquired MET amplification. Acquired mutations were subclonal and polyclonal, with evidence of increased tumor mutation rate with Enco+Cetux±Bini and mutational signatures (SBS17a/b). These findings support treatment with Enco+Cetux±Bini for patients with BRAF-V600E-mutant mCRC and provide insights into the biology of response and resistance to MAPK-pathway-targeted therapy. ClinicalTrials.gov registration: NCT02928224.

BRAFV600E-Mutant Metastatic Colorectal Cancer: Current Evidence, Future Directions, and Research Priorities

BRAFV600E-mutant metastatic colorectal cancer represents a distinct molecular phenotype known for its aggressive biological behavior, resistance to standard therapies, and poor survival rates. Improved understanding of the biology of the BRAF oncogene has led to the development of targeted therapies that have paved the way for a paradigm shift in managing this disease. However, despite significant recent advancements, responses to targeted therapies are short-lived, and several challenges remain. In this review, we discuss how progress in treating BRAFV600E-mutant metastatic colorectal cancer has been made through a better understanding of its unique biological and clinical features. We provide an overview of the evidence to support current treatment approaches and discuss critical areas of need and future research strategies that hold the potential to refine clinical practice further. We also discuss some challenging aspects of managing this disease, particularly the complexity of acquired resistance mechanisms that develop under the selective pressure of targeted therapies and rational strategies being investigated to overcome them.

Efficacy and safety of the combination of encorafenib/cetuximab with or without binimetinib in patients with BRAF V600E-mutated metastatic colorectal cancer: an AGEO real-world multicenter study

BACKGROUND

The combination of encorafenib with cetuximab has become the standard of care in patients with BRAF V600E-mutated metastatic colorectal cancer (mCRC) after a prior systemic therapy. This study aims to describe the efficacy and safety of encorafenib/cetuximab +/- binimetinib in patients with BRAF V600E-mutated mCRC in a real-world setting.

PATIENTS AND METHODS

This retrospective study included patients with BRAF V600E-mutated mCRC who received this combination from January 2020 to June 2022 in 30 centers.

RESULTS

A total of 201 patients were included, with 55% of women, a median age of 62 years, and an Eastern Cooperative Oncology Group performance status (ECOG-PS) >1 in 20% of cases. The main tumor characteristics were 60% of right-sided primary tumor, 11% of microsatellite instability/mismatch repair deficient phenotype, and liver and peritoneum being the two main metastatic sites (57% and 51%). Encorafenib/cetuximab +/- binimetinib was prescribed in the first, second, third, and beyond third line in 4%, 56%, 29%, and 11%, respectively, of cases, with the encorafenib/cetuximab/binimetinib combination for 21 patients (10%). With encorafenib/cetuximab treatment, 21% of patients experienced grade ≥3 adverse events (AEs), with each type of grade ≥3 AE observed in <5% of patients. The objective response rate was 32.2% and the disease control rate (DCR) was 71.2%. The median progression-free survival (PFS) was 4.5 months [95% confidence interval (CI) 3.9-5.4 months] and the median overall survival (OS) was 9.2 months (95% CI 7.8-10.8 months). In multivariable analysis, factors associated with a shorter PFS were synchronous metastases [hazard ratio (HR) 1.66, P = 0.04] and ECOG-PS >1 (HR 1.88, P = 0.007), and those associated with a shorter OS were the same factors (HR 1.71, P = 0.03 and HR 2.36, P < 0.001, respectively) in addition to treatment beyond the second line (HR 1.74, P = 0.003) and high carcinoembryonic antigen level (HR 1.72, P = 0.003).

CONCLUSION

This real-world study showed that in patients with BRAF V600E-mutated mCRC treated with encorafenib/cetuximab +/- binimetinib, efficacy and safety data confirm those reported in the BEACON registration trial. The main poor prognostic factors for this treatment are synchronous metastases and ECOG-PS >1.

Hereditary Colorectal Cancer Syndromes and Inflammatory Bowel Diseases: Risk Management and Surveillance Strategies

Background and aims: Hereditary colorectal cancer syndromes (HCCS), including familial adenomatous polyposis (FAP) and Lynch syndrome (LS), are the two most important high-risk conditions for colorectal cancer (CRC). Inflammatory bowel disease (IBD) increases the risk by two to six times compared with that in the general population. The intersection of these two conditions has rarely been documented in literature. We aimed to summarize the prevalence, pathogenesis, and current evidence-based management of IBD and HCCS and the underlying molecular mechanisms of accelerated carcinogenesis due to combined inflammation and genetic predisposition. Methods: PubMed and Scopus were searched until June 2024 to identify relevant studies investigating the epidemiology, pathogenesis, and management of IBD and coexisting hereditary CRC syndromes. Results: Co-occurrence of IBD and hereditary CRC syndromes is exceptionally uncommon. Individuals with LS and IBD tend to develop CRC at a younger age than those without IBD, with patients with ulcerative colitis facing particularly elevated risks. The interaction between mismatch deficiency and chronic inflammation requires further investigation.

Targeting the EGFR signalling pathway in metastatic colorectal cancer

Epidermal growth factor receptor (EGFR) and its activated downstream signalling pathways play a crucial role in colorectal cancer development and progression. After four decades of preclinical, translational, and clinical research, it has been shown that blocking the EGFR signalling pathway at different molecular levels represents a fundamental therapeutic strategy for patients with metastatic colorectal cancer. Nevertheless, the efficacy of molecularly targeted therapies is inescapably limited by the insurgence of mechanisms of acquired cancer cell resistance. Thus, in the era of precision medicine, a deeper understanding of the complex molecular landscape of metastatic colorectal cancer is required to deliver the best treatment choices to all patients. Major efforts are currently ongoing to improve patient selection, improve the efficacy of available treatments targeting the EGFR pathway, and develop novel combination strategies to overcome therapy resistance within the continuum of care of metastatic colorectal cancer.

A comprehensive overview of the molecular features and therapeutic targets in BRAFV600E-mutant colorectal cancer

As one of the most prevalent digestive system tumours, colorectal cancer (CRC) poses a significant threat to global human health. With the emergence of immunotherapy and target therapy, the prognosis for the majority of CRC patients has notably improved. However, the subset of patients with BRAF exon 15 p.V600E mutation (BRAFV600E) has not experienced remarkable benefits from these therapeutic advancements. Hence, researchers have undertaken foundational investigations into the molecular pathology of this specific subtype and clinical effectiveness of diverse therapeutic drug combinations. This review comprehensively summarised the distinctive molecular features and recent clinical research advancements in BRAF-mutant CRC. To explore potential therapeutic targets, this article conducted a systematic review of ongoing clinical trials involving patients with BRAFV600E-mutant CRC.

Microsatellite instability: A 2024 update

Deficient mismatch repair (dMMR) results in microsatellite instability (MSI), a pronounced mutator phenotype. High-frequency MSI (MSI-H)/dMMR is gaining increasing interest as a biomarker for advanced cancer patients to determine their eligibility for immune checkpoint inhibitors (ICIs). Various methods based on next-generation sequencing (NGS) have been developed to assess the MSI status. Comprehensive genomic profiling (CGP) testing can precisely ascertain the MSI status as well as genomic alterations in a single NGS test. The MSI status can be also ascertained through the liquid biopsy-based CGP assays. MSI-H has thus been identified in various classes of tumors, resulting in a greater adoption of immunotherapy, which is hypothesized to be effective against malignancies that possess a substantial number of mutations and/or neoantigens. NGS-based studies have also characterized MSI-driven carcinogenesis, including significant rates of fusion kinases in colorectal cancers (CRCs) with MSI-H that are targets for therapeutic kinase inhibitors, particularly in MLH1-methylated CRCs with wild-type KRAS/BRAF. NTRK fusion is linked to the colorectal serrated neoplasia pathway. Recent advances in investigations of MSI-H malignancies have resulted in the development of novel diagnostic or therapeutic techniques, such as a synthetic lethal therapy that targets the Werner gene. DNA sensing in cancer cells is required for antitumor immunity induced by dMMR, opening up novel avenues and biomarkers for immunotherapy. Therefore, clinical relevance exists for analyses of MSI and MSI-H-associated genomic alterations in malignancy. In this article, we provide an update on MSI-driven carcinogenesis, with an emphasis on unique landscapes of diagnostic and immunotherapeutic strategies.

CXCL16 promotes tumor metastasis by regulating angiogenesis in the tumor micro-environment of BRAF V600E mutant colorectal cancer

Patients of colorectal cancer (CRC) with BRAF V600E mutation obtain poor prognosis. This study aimed to explore the role and mechanism of BRAF V600E mutation in angiogenesis of tumor micro-environment (TME). It has been reported that CXCL16 expression in TME is closely related to BRAF mutation. Clinicopathological features of CRC with BRAF V600E mutant or wild type were collected in this study. Immunohistochemistry (IHC) assays were conducted to test the expressions of vascular endothelial growth factor (VEGF), CD31 and CXCL16. ROC curve was used to determine the optimal cut off values of CXCL16. A total of 680 patients including 141 BRAF V600E type and 679 wild type were included. BRAF V600E mutant tumors were presented with significant worse clinicopathological features and a shorter overall survival (OS) than wild-type. Besides, chemokines CXCL16 was up-regulated in BRAF V600E mutant tissues and was associated with poorer prognosis. In addition, VEGF levels and vascular endothelial cell density was significantly increased in BRAF mutation. At last, CXCL16 was positively correlated with VEGF expression and vascular endothelial cell density. In conclusion, BRAF V600E mutations may promote metastasis of CRC by regulating CXCL16 expression and promoting angiogenesis in the TME.

Colorectal Cancer Risk Prediction Using the rs4939827 Polymorphism of the SMAD7 Gene in the Romanian Population

Colorectal cancer (CRC) is globally recognized as a prevalent malignancy known for its significant mortality rate. Recent years have witnessed a rising incidence trend in colorectal cancer, emphasizing the necessity for early diagnosis. Our study focused on examining the impact of the SMAD7 gene variant rs4939827 on the risk of colorectal cancer occurrence. The composition of our study group included 340 individuals, comprising 170 CRC diagnosed patients and 170 healthy controls. We performed genotyping of all biological samples using the TaqMan assay on the ABI 7500 Real-Time PCR System (Applied Biosystems, Waltham, MA, USA). This investigation focused on the rs4939827 gene variant, assessing its association with CRC risk and clinicopathological characteristics. Genotyping results for the SMAD7 gene variant rs4939827 revealed a 42.6% prevalence of the C allele in CRC patients (p = 0.245) and a 22.8% prevalence of the T allele in control subjects (p = 0.109). This study concluded that there was an elevated risk of CRC in the dominant model for CC/CT+TT, with a p-value of 0.113 and an odds ratio (OR) of 2.781, within a 95% confidence interval (CI) of 0.998 to 3.456. The findings of our research indicate a correlation between variants of the SMAD7 gene and the likelihood of developing colorectal cancer in our study population. Consequently, these results could be instrumental in facilitating early diagnosis of colorectal cancer utilizing information on single-nucleotide polymorphism (SNP) and genetic susceptibility to the disease.

Detecting colorectal cancer using genetic and epigenetic biomarkers: screening and diagnosis

Colorectal cancer (CRC) is one of the most frequent types of cancer, with high incidence rates and mortality globally. The extended timeframe for developing CRC allows for the potential screening and early identification of the disease. Furthermore, studies have shown that survival rates for patients with cancer are increased when diagnoses are made at earlier stages. Recent research suggests that the development of CRC, including its precancerous lesion, is influenced not only by genetic factors but also by epigenetic variables. Studies suggest epigenetics plays a significant role in cancer development, particularly CRC. While this approach is still in its early stages and faces challenges due to the variability of CRC, it shows promise as a potential method for understanding and addressing the disease. This review examined the current evidence supporting genetic and epigenetic biomarkers for screening and diagnosis. In addition, we also discussed the feasibility of translating these methodologies into clinical settings. Several markers show promising potential, including the methylation of vimentin (VIM), syndecan-2 (SDC2), and septin 9 (SEPT9). However, their application as screening and diagnostic tools, particularly for early-stage CRC, has not been fully optimized, and their effectiveness needs validation in large, multi-center patient populations. Extensive trials and further investigation are required to translate genetic and epigenetic biomarkers into practical clinical use. biomarkers, diagnostic biomarkers.

Opposing roles by KRAS and BRAF mutation on immune cell infiltration in colorectal cancer - possible implications for immunotherapy

BACKGROUND

The immune response has important clinical value in colorectal cancer (CRC) in both prognosis and response to immunotherapy. This study aims to explore tumour immune cell infiltration in relation to clinically well-established molecular markers of CRC.

METHODS

Multiplex immunohistochemistry and multispectral imaging was used to evaluate tumour infiltration of cytotoxic T cells (CD8+), Th1 cells (T-bet+), T regulatory cells (FoxP3+), B cells (CD20+), and macrophages (CD68+) in a cohort of 257 CRC patients.

RESULTS

We found the expected association between higher immune-cell infiltration and microsatellite instability. Also, whereas BRAF-mutated tumours displayed increased immune-cell infiltration compared to BRAF wild-type tumours, the opposite was seen for KRAS-mutated tumours, differences that were most prominent for cytotoxic T cells and Th1 cells. The opposing relationships of BRAF and KRAS mutations with tumour infiltration of cytotoxic T cells was validated in an independent cohort of 608 CRC patients. A positive prognostic importance of cytotoxic T cells was found in wild-type as well as KRAS and BRAF-mutated CRCs in both cohorts.

CONCLUSION

A combined evaluation of MSI status, KRAS and BRAF mutational status, and immune infiltration (cytotoxic T cells) may provide important insights to prognosis and response to immunotherapy in CRC.

Evaluation of Fluctuations of BRAF Gene Expression and its Polymorphism at rs1267623 in Colorectal Cancer

BACKGROUND

Molecular markers in Colorectal Cancer (CRC) are needed for more accurate classification and personalized treatment. In this way, we investigated the effects of the BRAF gene on clinical outcomes of its expression fluctuations and its polymorphism at rs1267623 in CRC.

METHODS

In this study, 36.36 percent of patients with CRC were women, and 63.63 percent were men. After the pathology department confirmed the tumor of the samples, the stage and grade of the tumor were determined according to the TNM system. Real-time PCR was used to check the expression of the BRAF gene in tumor and non-tumor tissues, and its polymorphism in rs1267623 was also checked using the Tetra-ARMs PCR technique.

RESULTS

The expression of BRAF in tumor tissues was significantly higher than in non-tumoral tissues (P = 0.001), indicating an upregulation of BRAF gene expression in tumoral tissues. The user's text is empty. Furthermore, there was a significant correlation between BRAF expression and tumor stage (P = 0.001), as well as tumor grade (P = 0.003). However, no significant link was found between lymph node metastasis and distant metastasis of BRAF gene expression (P = 0.3). Additionally, no mutation was detected in the investigation of rs1267623 polymorphism.

CONCLUSION

The BRAF gene was upregulated in tumoral tissues. Remarkably, no mutation was found in the rs1267623 polymorphism. As a result, this gene can be used as a biomarker in the diagnosis and treatment of CRC.

Real-World Outcomes of First-Line FOLFIRI Plus Bevacizumab with Irinotecan Dose Escalation versus FOLFOXIRI Plus Bevacizumab in BRAFV600E-Mutant Metastatic Colorectal Cancer: The Preliminary Data from a Single-Center Observational Study

Background and Objectives: Approximately 5-10% of all patients with metastatic colorectal cancer (mCRC) harbor a BRAFV600E mutation. These patients exhibit distinct metastatic patterns, poor prognosis, and heterogenous survival outcomes. The findings from the TRIBE study indicated that the administration of FOLFOXIRI plus bevacizumab as first-line treatment extended the median duration of overall survival (OS). In this study, we explored the effects of UGT1A1 polymorphism on the outcomes of irinotecan dose escalation versus FOLFOXIRI plus bevacizumab in patients with BRAFV600E-mutant mCRC. Materials and Methods: We retrospectively reviewed the medical records of 25 patients who had received a diagnosis of BRAFV600E-mutant mCRC between October 2015 and August 2022. All patients underwent UGT1A1 genotyping before receiving bevacizumab plus FOLFIRI. The primary end point was progression-free survival (PFS), and secondary endpoints were OS and adverse events (AEs). The two treatment arms were compared in terms of 6-month PFS and 12-month OS. Results: Over a median follow-up duration of 15.0 (interquartile range, 10.0-30.5) months, no significant differences were noted between the treatment arms in severe AEs (SAEs), 6-month PFS, or 12-month OS (all p < 0.05). Regarding AEs, the FOLFIRI plus bevacizumab regimen was associated with a lower incidence of anorexia than was the FOLFOXIRI plus bevacizumab regimen (p = 0.042). Conclusions: Our findings indicate that FOLFIRI plus bevacizumab with irinotecan dose escalation is an effective first-line treatment regimen for patients with BRAFV600E-mutant mCRC. This regimen leads to acceptable clinical outcomes with manageable AEs. However, the effects on survival and safety outcomes could only be speculated, and further studies are needed because of the sample size, the follow-up for the OS evaluation, and the non-uniformity in all the variables considered in the two groups.

Metabolic interventions to enhance immunotherapy and targeted therapy efficacy in advanced colorectal cancer

Current standard-of-care for metastatic colorectal cancer patients includes chemotherapy and anti-angiogenic or anti-epidermal growth factor receptor for microsatellite stable tumors and pembrolizumab for microsatellite instable tumors. However, despite the available therapies, the prognosis remains poor. In recent years, new drugs combined with immune checkpoint inhibitors have been tested in microsatellite stable metastatic colorectal cancer patients, but the benefit was modest. Here, we review the metabolic interactions between the immune microenvironment and cancer cells. More specifically, we highlight potential correlatives of tumor immune and metabolic features with transcriptomic classifications such as the Consensus Molecular Subtype. Finally, we discuss the unmet need of immune-metabolic signatures and the value of a new signature (IMMETCOLS) for guiding new strategies in metastatic colorectal cancer. We conclude that the field is ready to propose customized strategies for modifying metabolism and improving immunotherapy and targeted therapy efficacy.

Time to recurrence and its relation to survival after recurrence in patients resected for stage III colon cancer

BACKGROUND

It is intuitively thought that early relapse is associated with poor survival after recurrence (SAR) in resected colon cancer (CC) patients, but this has never been formally studied.

METHODS

We pooled data from stage III patients treated with oxaliplatin-based adjuvant therapy in two phase III trials, to analyse time to recurrence (TTR) and its relationship with SAR. TTR and SAR were also studied according to molecular status (mismatch repair (MMR), RAS, and BRAFV600E). Early relapsing patients were defined as patients having a TTR event within 12 months after starting adjuvant chemotherapy.

RESULTS

4548 stage III CC patients were included in the present analysis. Deficient MMR (dMMR) CC patients experienced fewer recurrences than proficient (p)MMR CC patients (18.8% versus 27.6%) but had a significantly shorter median TTR (mTTR; 0.74 versus 1.40 years, p < 0.0001). In pMMR patients, BRAF and RAS mutations were also associated with earlier mTTR as compared to double wild-type (WT) patients (0.99 versus 1.38 versus 1.54 years, respectively, p < 0.0001). Early recurrence occurred in 397 patients and was associated with a median SAR (2.2 versus 3.3 years, p = 0.0007). However, this association was mainly due to pMMR/RAS and BRAFV600E mutated tumours and was not confirmed in dMMR and pMMR/double WT subgroups.

CONCLUSION

In resected stage III CC treated with standard oxaliplatin-based adjuvant therapy, TTR varies between dMMR, pMMR/RAS, or BRAFV600E mutated and pMMR/double WT tumours. In addition, early relapse is associated with poor survival, mainly due to patients resected for a pMMR/RAS or BRAFV600E mutated tumour.

The EMT factor ZEB1 paradoxically inhibits EMT in BRAF-mutant carcinomas

Despite being in the same pathway, mutations of KRAS and BRAF in colorectal carcinomas (CRCs) determine distinct progression courses. ZEB1 induces an epithelial-to-mesenchymal transition (EMT) and is associated with worse progression in most carcinomas. Using samples from patients with CRC, mouse models of KrasG12D and BrafV600E CRC, and a Zeb1-deficient mouse, we show that ZEB1 had opposite functions in KRAS- and BRAF-mutant CRCs. In KrasG12D CRCs, ZEB1 was correlated with a worse prognosis and a higher number of larger and undifferentiated (mesenchymal or EMT-like) tumors. Surprisingly, in BrafV600E CRC, ZEB1 was associated with better prognosis; fewer, smaller, and more differentiated (reduced EMT) primary tumors; and fewer metastases. ZEB1 was positively correlated in KRAS-mutant CRC cells and negatively in BRAF-mutant CRC cells with gene signatures for EMT, cell proliferation and survival, and ERK signaling. On a mechanistic level, ZEB1 knockdown in KRAS-mutant CRC cells increased apoptosis and reduced clonogenicity and anchorage-independent growth; the reverse occurred in BRAFV600E CRC cells. ZEB1 is associated with better prognosis and reduced EMT signature in patients harboring BRAF CRCs. These data suggest that ZEB1 can function as a tumor suppressor in BRAF-mutant CRCs, highlighting the importance of considering the KRAS/BRAF mutational background of CRCs in therapeutic strategies targeting ZEB1/EMT.

Tumor Cell Resistance to the Inhibition of BRAF and MEK1/2

BRAF is one of the most frequently mutated oncogenes, with an overall frequency of about 50%. Targeting BRAF and its effector mitogen-activated protein kinase kinase 1/2 (MEK1/2) is now a key therapeutic strategy for BRAF-mutant tumors, and therapies based on dual BRAF/MEK inhibition showed significant efficacy in a broad spectrum of BRAF tumors. Nonetheless, BRAF/MEK inhibition therapy is not always effective for BRAF tumor suppression, and significant challenges remain to improve its clinical outcomes. First, certain BRAF tumors have an intrinsic ability to rapidly adapt to the presence of BRAF and MEK1/2 inhibitors by bypassing drug effects via rewired signaling, metabolic, and regulatory networks. Second, almost all tumors initially responsive to BRAF and MEK1/2 inhibitors eventually acquire therapy resistance via an additional genetic or epigenetic alteration(s). Overcoming these challenges requires identifying the molecular mechanism underlying tumor cell resistance to BRAF and MEK inhibitors and analyzing their specificity in different BRAF tumors. This review aims to update this information.

BRAFV600E-mutated serrated colorectal neoplasia drives transcriptional activation of cholesterol metabolism

BRAF mutations occur early in serrated colorectal cancers, but their long-term influence on tissue homeostasis is poorly characterized. We investigated the impact of short-term (3 days) and long-term (6 months) expression of BrafV600E in the intestinal tissue of an inducible mouse model. We show that BrafV600E perturbs the homeostasis of intestinal epithelial cells, with impaired differentiation of enterocytes emerging after prolonged expression of the oncogene. Moreover, BrafV600E leads to a persistent transcriptional reprogramming with enrichment of numerous gene signatures indicative of proliferation and tumorigenesis, and signatures suggestive of metabolic rewiring. We focused on the top-ranking cholesterol biosynthesis signature and confirmed its increased expression in human serrated lesions. Functionally, the cholesterol lowering drug atorvastatin prevents the establishment of intestinal crypt hyperplasia in BrafV600E-mutant mice. Overall, our work unveils the long-term impact of BrafV600E expression in intestinal tissue and suggests that colorectal cancers with mutations in BRAF might be prevented by statins.

A Contrast-Enhanced CT-Based Deep Learning System for Preoperative Prediction of Colorectal Cancer Staging and RAS Mutation

PURPOSE

This study aimed to build a deep learning system using enhanced computed tomography (CT) portal-phase images for predicting colorectal cancer patients' preoperative staging and RAS gene mutation status.

METHODS

The contrast-enhanced CT image dataset comprises the CT portal-phase images from a retrospective cohort of 231 colorectal cancer patients. The deep learning system was developed via migration learning for colorectal cancer detection, staging, and RAS gene mutation status prediction. This study used pre-trained Yolov7, vision transformer (VIT), swin transformer (SWT), EfficientNetV2, and ConvNeXt. 4620, and contrast-enhanced CT images and annotated tumor bounding boxes were included in the tumor identification and staging dataset. A total of 19,700 contrast-enhanced CT images comprise the RAS gene mutation status prediction dataset.

RESULTS

In the validation cohort, the Yolov7-based detection model detected and staged tumors with a mean accuracy precision (IoU = 0.5) (mAP_0.5) of 0.98. The area under the receiver operating characteristic curve (AUC) in the test set and validation set for the VIT-based prediction model in predicting the mutation status of the RAS genes was 0.9591 and 0.9554, respectively. The detection network and prediction network of the deep learning system demonstrated great performance in explaining contrast-enhanced CT images.

CONCLUSION

In this study, a deep learning system was created based on the foundation of contrast-enhanced CT portal-phase imaging to preoperatively predict the stage and RAS mutation status of colorectal cancer patients. This system will help clinicians choose the best treatment option to increase colorectal cancer patients' chances of survival and quality of life.

Predictive Impact of RNF43 Mutations in Patients With Proficient Mismatch Repair/Microsatellite Stable BRAFV600E-Mutated Metastatic Colorectal Cancer Treated With Target Therapy or Chemotherapy

PURPOSE

Target therapy (TT) with encorafenib plus cetuximab is a standard option in patients with BRAFV600E-mutated (mut) pretreated metastatic colorectal cancer (mCRC). Recently, mutations in RNF43, encoding a negative regulator of the WNT pathway, were associated with longer progression-free survival (PFS) and overall survival (OS) in patients with proficient mismatch repair/microsatellite stable (pMMR/MSS) BRAFV600E-mut mCRC treated with TT. Here, we explored the effect of RNF43 mutations on the efficacy of second-line TT versus standard chemotherapy (CT).

METHODS

A retrospective cohort of patients with pMMR/MSS BRAFV600E-mut tumors, available RNF43 mutational status, and treated with second-line TT or oxaliplatin- and/or irinotecan-based CT was analyzed.

RESULTS

One hundred thirty-two patients with pMMR/MSS BRAFV600E-mut mCRC were included. RNF43 was found mut in 34 (26%) cases. Among RNF43 mutants, TT was associated with longer PFS (7.7 v 3.0 months; P = .002) and higher overall response rate (ORR; 45% v 0%; P = .009) compared with CT. Conversely, among RNF43 wild-type (wt) patients, only a trend for longer PFS (4.5 v 3.7 months; P = .064) favoring TT, with no differences in ORR (P = .14), was observed. After excluding 36 patients receiving TT in third line or beyond, a longer OS (19.4 v 10.1 months; P = .022) and a numerically OS advantage (10.6 v 6.6 months; P = .068) were reported for TT both in the RNF43-mut and in the RNF43 wt groups. However, no interaction effect was reported between RNF43 mutational status and treatment in ORR (Pinteraction = .96), PFS (Pinteraction = .13), and OS (Pinteraction = .44).

CONCLUSION

Patients with pMMR/MSS BRAFV600E-mut mCRC achieve benefit from TT versus CT independently of RNF43 mutational status, although a higher magnitude of benefit from TT is observed in RNF43-mut tumors. These findings deserve confirmation in concluded and ongoing randomized trials.

Microsatellite instability states serve as predictive biomarkers for tumors chemotherapy sensitivity

There is an urgent need for markers to predict the efficacy of different chemotherapy drugs. Herein, we examined whether microsatellite instability (MSI) status can predict tumor multidrug sensitivity and explored the underlying mechanisms. We downloaded data from several public databases. Drug sensitivity was compared between the high microsatellite instability (MSI-H) and microsatellite-stable/low microsatellite instability (MSS/MSI-L) groups. In addition, we performed pathway enrichment analysis and cellular chemosensitivity assays to explore the mechanisms by which MSI status may affect drug sensitivity and assessed the differences between drug-treated and control cell lines. We found that multiple MSI-H tumors were more sensitive to a variety of chemotherapy drugs than MSS/MSI-L tumors, and especially for CRC, chemosensitivity is enhanced through the downregulation of DDR pathways such as NHEJ. Additional DNA damage caused by chemotherapeutic drugs results in further downregulation of DDR pathways and enhances drug sensitivity, forming a cycle of increasing drug sensitivity.

Strategic Insight into the Combination Therapies for Metastatic Colorectal Cancer

Colorectal cancer (CRC) is the second most common cause of cancer-related deaths worldwide. The 5-year survival rate after curative resection is almost 80%, however, it is still less than satisfactory for metastatic CRC (mCRC). The combination approach including surgery, chemotherapy, molecular targeted therapy, and immunotherapy is a promising strategy due to its synergistic anticancer effect. Moreover, circulating tumor DNA (ctDNA) analysis has been reported to stratify the post-operative risk of recurrence, thus providing clinically valuable information for deciding to conduct adjuvant chemotherapy. Furthermore, multiple new drugs that potentially target undruggable genes, including KRAS, have been developed. In this review, we discuss the current management of patients with mCRC and future perspectives in the light of a combination therapeutic strategy.

Treatment of BRAF-V600E mutant metastatic colorectal cancer: new insights and biomarkers

INTRODUCTION

The presence of a BRAF-V600E mutation in metastatic colorectal cancer (mCRC) is observed in approximately 12% of cases and is associated with poor prognosis and aggressive disease. Unlike melanoma, the development of successful BRAF blockade in colorectal cancer has been complex. The phase III BEACON trial made significant progress in the development of BRAF inhibitors by establishing encorafenib-cetuximab as the new standard of care for patients with mCRC who have progressed to one or two previous lines of treatment. Nonetheless, not all patients respond to encorafenib-based combinations, and some responses are short-lived. Identifying new strategies to boost antitumor activity and improve survival is paramount.

AREAS COVERED

The development of targeted therapy for BRAF-V600E mCRC starting with BRAF inhibitors as monotherapy through novel combinations with anti-VEGF or anti-PD1 agents to enhance antitumor activity is reviewed, with a particular focus on the development of predictive and prognostic biomarkers.

EXPERT OPINION

There is a crucial need to better understand tumor biology and develop accurate and reliable biomarkers to enhance the antitumor activity of encorafenib-based combinations. The RNF43 mutation is an accurate and reliable predictive biomarker of response, and combinations that target crosstalk between the MAPK pathway, the immune system, and WNT pathways seem promising.

Methods and biomarkers for early detection, prediction, and diagnosis of colorectal cancer

Colorectal cancer (CRC) is one of the most common digestive diseases worldwide. It has steadily ascended to the top three cancers in terms of incidence and mortality. The primary cause is the inability to diagnose it at an early stage. Therefore, early detection and diagnosis are essential for colorectal cancer prevention. Although there are now various methods for CRC early detection, in addition to recent developments in surgical and multimodal therapy, the poor prognosis and late detection of CRC still remain significant. Thus, it is important to investigate novel technologies and biomarkers to improve the sensitization and specification of CRC diagnosis. Here, we present some common methods and biomarkers for early detection and diagnosis of CRC, we hope this review will encourage the adoption of screening programs and the clinical use of these potential molecules as biomarkers for CRC early detection and prognosis.

Immune checkpoint blockade therapy for BRAF mutant metastatic colorectal cancer: the efficacy, new strategies, and potential biomarkers

BRAF mutant metastatic colorectal cancer has long been considered a tumor with a poor prognosis and a poor response to chemotherapy. Despite the efficacy of targeted therapy with multi-targeted blockade of the mitogen-activated protein kinase (MAPK) signaling pathway has brought a glimmer of hope to this group of patients, the need to improve treatment efficacy remains unmet, especially for the microsatellite stability/DNA proficient mismatch repair (MSS/pMMR) subtype. BRAF mutant colorectal cancer patients with high microsatellite instability/DNA deficient mismatch repair (MSI-H/dMMR) have high tumor mutation burden and abundant neoantigen, who are deemed as ones that could receive expected efficacy from immunotherapy. Generally, it is believed that MSS/pMMR colorectal cancer is an immunologically "cold" tumor that is insensitive to immunotherapy. However, targeted therapy combined with immune checkpoint blockade therapy seems to bring light to BRAF mutant colorectal cancer patients. In this review, we provide an overview of clinical efficacy and evolving new strategies concerning immune checkpoint blockade therapy for both MSI-H/dMMR and MSS/pMMR BRAF mutant metastatic colorectal cancer and discuss the potential biomarkers in the tumor immune microenvironment for predicting immunotherapeutic response in BRAF mutant colorectal cancer.

The BEETS (JACCRO CC-18) trial: an observational and translational study of BRAF-mutated metastatic colorectal cancer

For BRAF V600E-mutated metastatic colorectal cancer (mCRC), the BEACON phase 3 trial showed survival benefit of triplet therapy with cetuximab (anti-EGFR antibody), encorafenib (BRAF inhibitor) and binimetinib (MEK inhibitor) as well as doublet therapy with cetuximab and encorafenib over irinotecan-based chemotherapy plus anti-EGFR antibody. Both regimens are standards of care in Japan, but definite biomarkers for predicting efficacy and selecting treatment remain lacking. The mechanisms underlying resistance to these regimens also warrant urgent exploration to further evolve treatment. This prospective observational/translational study evaluated real-word clinical outcomes with cetuximab and encorafenib with or without binimetinib for BRAF-mutated mCRC patients and investigated biomarkers for response and resistance by collecting blood samples before and after treatment. Clinical Trial Registration: UMIN000045530 (https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000051983).

Plasmatic BRAF-V600E allele fraction as a prognostic factor in metastatic colorectal cancer treated with BRAF combinatorial treatments

BACKGROUND

Combination of a BRAF inhibitor (BRAFi) and an anti-epidermal growth factor receptor (EGFR), with or without a MEK inhibitor (MEKi), improves survival in BRAF-V600E-mutant metastatic colorectal cancer (mCRC) over standard chemotherapy. However, responses are heterogeneous and there are no available biomarkers to assess patient prognosis or guide doublet- or triplet-based regimens. In order to better characterize the clinical heterogeneity observed, we assessed the prognostic and predictive role of the plasmatic BRAF allele fraction (AF) for these combinations.

PATIENTS AND METHODS

A prospective discovery cohort including 47 BRAF-V600E-mutant patients treated with BRAFi-anti-EGFR ± MEKi in clinical trials and real-world practice was evaluated. Results were validated in an independent multicenter cohort (n= 29). Plasmatic BRAF-V600E AF cut-off at baseline was defined in the discovery cohort with droplet digital PCR (ddPCR). All patients had tissue-confirmed BRAF-V600E mutations.

RESULTS

Patients with high AF have major frequency of liver metastases and more metastatic sites. In the discovery cohort, median progression-free survival (PFS) and overall survival (OS) were 4.4 and 10.1 months, respectively. Patients with high BRAF AF (≥2%, n = 23) showed worse PFS [hazard ratio (HR) 2.97, 95% confidence interval (CI) 1.55-5.69; P = 0.001] and worse OS (HR 3.28, 95% CI 1.58-6.81; P = 0.001) than low-BRAF AF patients (<2%, n = 24). In the multivariable analysis, BRAF AF levels maintained independent significance. In the validation cohort, high BRAF AF was associated with worse PFS (HR 3.83, 95% CI 1.60-9.17; P = 0.002) and a trend toward worse OS was observed (HR 1.86, 95% CI 0.80-4.34; P = 0.15). An exploratory analysis of predictive value showed that high-BRAF AF patients (n = 35) benefited more from triplet therapy than low-BRAF AF patients (n = 41; PFS and OS interaction tests, P < 0.01).

CONCLUSIONS

Plasmatic BRAF AF determined by ddPCR is a reliable surrogate of tumor burden and aggressiveness in BRAF-V600E-mutant mCRC treated with a BRAFi plus an anti-EGFR with or without a MEKi and identifies patients who may benefit from treatment intensification. Our results warrant further validation of plasmatic BRAF AF to refine clinical stratification and guide treatment strategies.

Metastatic pattern is a prognostic factor in BRAFV600E mutant colorectal cancer

BACKGROUND

Despite recent advancements in the treatment of metastatic BRAF^V600E colorectal cancer (CRC), prognosis remains poor. However, a some patients with BRAF^V600E disease have superior outcomes compared to the overall cohort and the prognostic factors associated with this improved survival are not well understood.

METHODS

We conducted a single center retrospective review of patients with metastatic CRC and available next generation sequencing data. Patients with confirmed BRAF^V600E disease were selected for the final analysis. We collected baseline demographic characteristics, concurrent mutations, and metastatic pattern. The primary endpoint was overall survival (OS). Univariate and multivariable logistic regression was used to examine the association between baseline concurrent somatic mutations and sites of metastatic disease with survival.

RESULTS

Of 466 patients with metastatic CRC, 50 harbored BRAF^V600E disease and 42 were included in the final analysis. The median OS in this cohort was 18.7 months (95% CI: 5.55-31.8). There was no association between baseline concurrent somatic mutations and OS. On univariate analysis, patients with lymph node only disease at the time of metastatic disease were more likely to have longer OS (hazard ratio [HR] = 0.30, 95% CI: 0.09-0.98, p = 0.047) and patients with peritoneal disease were more likely to have shorter OS (HR = 2.78, 95% CI: 1.12-6.88, p = 0.03). However, these associations did not retain statistical significance on multivariable analysis.

CONCLUSIONS

The pattern of metastatic disease in BRAF^V600E CRC may be a prognostic factor and future studies are needed to better understand the underlying mechanisms and potentially change clinical practice for a select patient population.

MICROABSTRACT

Select patients with metastatic BRAF^V600E colorectal cancer may have better than expected survival but are not well characterized. We conducted a retrospective review of 42 patients with metastatic BRAF^V600E colorectal cancer and showed that lymph node only disease at the time of metastatic disease was associated with superior survival.

Secretome Screening of BRAFV600E-Mutated Colon Cancer Cells Resistant to Vemurafenib

Patients with metastatic colorectal cancer (mCRC) carrying BRAFV600E mutation have worse response to chemotherapy and poor prognosis. The BRAFV600E inhibitor vemurafenib has shown modest efficacy as monotherapy in BRAF-mutated mCRC due to the development of resistance. The aim of this study was to conduct a comparative proteomics profiling of the secretome from vemurafenib-sensitive vs. -resistant colon cancer cells harboring BRAFV600E mutation in order to identify specific secretory features potentially associated with changes in the resistant cells' phenotype. Towards this aim, we employed two complementary proteomics approaches including two-dimensional gel electrophoresis coupled with MALDI-TOF/TOF mass spectrometry and label-free quantitative LC-MS/MS analysis. Obtained results pointed to aberrant regulation of DNA replication and endoplasmic reticulum stress as the major secretome features associated with chemoresistant phenotype. Accordingly, two proteins implicated in these processes including RPA1 and HSPA5/GRP78 were discussed in more details in the context of biological networks and their importance as potential secretome targets for further functional and clinical evaluation. Expression patterns of RPA1 and HSPA5/GRP78 in tumor tissues from colon cancer patients were also found in additional in silico analyses to be associated with BRAFV600E mutation status, which opens the possibility to extrapolate our findings and their clinical implication to other solid tumors harboring BRAFV600E mutation, such as melanoma.

Advances and prospects of drug clinical research in colorectal cancer in 2022

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer death worldwide. Clinical research results have provided more treatment opportunities for CRC patients, showing that an optimal combination of existing drugs and new drugs is needed to mitigate the burden of this disease. In this review, we have summarized recent advances in drug clinical research for CRC in 2022, including chemotherapy, targeted therapy, and immunotherapy, to find opportunities for substantial improvements in drug discovery and clinical development methods.

Real-world treatment and outcomes of patients with metastatic BRAF mutant colorectal cancer

BACKGROUND

BRAF mutation occurs in 5%-10% of metastatic colorectal cancers (mCRCs). Patients with BRAF mutant mCRC exhibit a specific metastatic pattern and poor prognosis. Survival outcomes are heterogeneous in cases of mCRC with a BRAF mutation. The optimal first-line therapy is still controversial.

METHODS

We retrospectively reviewed the medical records of patients with mCRC between June 2010 and December 2021. Clinicopathologic characteristics, treatment and BRAF mutation testing results were collected. Patients with a BRAF mutation were included. Kaplan-Meier methods and log-rank tests were used to analyze and compare survival. Cox proportional hazards regression was used to establish the predictive nomogram model.

RESULTS

Of the 4475 mCRC, 261 have a BRAF mutation, including 240 V600E and 21 non-V600E mutants. The median overall survival (OS) was 18.2 months in the BRAF V600E mutant group versus 38.0 months in the non-V600E mutant group (p = 0.022). ECOG score, tumor differentiation, liver metastasis, bone metastasis and primary tumor resection were independent prognostic factors for the OS of BRAF V600E mutant mCRC. A nomogram model was established using these factors. The median OS was 39.3 m, 18.2 m and 10.7 m for the low-risk, intermediate-risk and high-risk groups defined by this model, respectively (p < 0.0001). Patients who received first-line triplet chemotherapy ± bevacizumab had comparable progression free survival (PFS) and OS compared with those treated with doublets ± bevacizumab.

CONCLUSION

BRAF V600E mutant mCRCs exhibit unfavorable and heterogeneous prognosis. The first-line intensive chemotherapy did not confer a marked impact on the PFS and OS.

European expert panel consensus on the clinical management of BRAFV600E-mutant metastatic colorectal cancer

Metastatic colorectal cancer (mCRC) is a heterogenous disease caused by various genetic alterations. The BRAF^V600E mutation occurs in approximately 8-12% of patients and is characterised by an aggressive clinical course and poor prognosis. Here we review the current knowledge on BRAF^V600E-mutant mCRC and provide a series of consensus statements on its clinical management. The treatment landscape for BRAF^V600E-mutant mCRC has changed greatly due to the emergence of molecular targeted therapies (including BRAF inhibitors) and immune checkpoint inhibitors. A scientific literature search identified available data on molecular testing, treatments, and clinical monitoring of patients with BRAF^V600E-mutant mCRC. Consensus statements were discussed and developed by a European expert panel. This manuscript provides consensus management guidance for different clinical presentations of BRAF^V600E-mutant mCRC and makes recommendations regarding treatment sequencing choices. To guide appropriate clinical management and treatment decisions for mCRC patients, tumour tissue analysis for DNA mismatch repair/microsatellite status and, at a minimum, KRAS, NRAS, and BRAF mutational status is mandatory at the time of diagnosis. Finally, we discuss the rapidly evolving treatment landscape for BRAF^V600E-mutant mCRC and define priorities for the development of novel therapeutic strategies that are needed to improve patient outcomes.

MmCMS: mouse models' consensus molecular subtypes of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) primary tumours are molecularly classified into four consensus molecular subtypes (CMS1-4). Genetically engineered mouse models aim to faithfully mimic the complexity of human cancers and, when appropriately aligned, represent ideal pre-clinical systems to test new drug treatments. Despite its importance, dual-species classification has been limited by the lack of a reliable approach. Here we utilise, develop and test a set of options for human-to-mouse CMS classifications of CRC tissue.

METHODS

Using transcriptional data from established collections of CRC tumours, including human (TCGA cohort; n = 577) and mouse (n = 57 across n = 8 genotypes) tumours with combinations of random forest and nearest template prediction algorithms, alongside gene ontology collections, we comprehensively assess the performance of a suite of new dual-species classifiers.

RESULTS

We developed three approaches: MmCMS-A; a gene-level classifier, MmCMS-B; an ontology-level approach and MmCMS-C; a combined pathway system encompassing multiple biological and histological signalling cascades. Although all options could identify tumours associated with stromal-rich CMS4-like biology, MmCMS-A was unable to accurately classify the biology underpinning epithelial-like subtypes (CMS2/3) in mouse tumours.

CONCLUSIONS

When applying human-based transcriptional classifiers to mouse tumour data, a pathway-level classifier, rather than an individual gene-level system, is optimal. Our R package enables researchers to select suitable mouse models of human CRC subtype for their experimental testing.

Adverse Events Associated with Encorafenib Plus Cetuximab in Patients with BRAFV600E-mutant Metastatic Colorectal Cancer: An in-depth Analysis of the BEACON CRC Study

BACKGROUND

The BRAF inhibitor encorafenib in combination with cetuximab was recently approved for patients with BRAF^V600E-mutated (BRAF^V600Emut) metastatic colorectal cancer (mCRC). Approval was based on positive results from the phase 3 BEACON CRC study in BRAF^V600Emut mCRC patients who had progressed after 1-2 previous regimens. This analysis provides a detailed examination of the adverse events (AEs) of interest (AEIs) with encorafenib+cetuximab in the BEACON study to aid gastrointestinal oncologists, given the limited experience with this combination.

MATERIALS AND METHODS

AEIs, including dermatological AEs, arthralgia/myalgia, nausea/vomiting, diarrhea, abdominal pain, fatigue/asthenia and nephrotoxicity, were examined in the doublet therapy group. Clinical characteristics associated with these AEs, AE grade, time to onset and time to resolution were also studied.

RESULTS

Safety analysis included 216/220 patients randomized to doublet therapy. The most commonly occurring AEI was dermatological toxicity (75.5%), followed by arthralgia/myalgia (56.0%) and fatigue/asthenia (56.0%). Other than nephrotoxicity (7 patients; 5/7 with Grade 3 or 4), most AEs were Grade 1 or 2. Most AEs were more common in women than men (nausea/vomiting, diarrhea, abdominal pain, dermatological AEs, and arthralgia/myalgia). Nausea/vomiting, abdominal pain and fatigue/asthenia were more common in patients aged ≥70 years. Most AEs developed early, within the first 1-2 months of treatment, and resolved within 1-2 weeks. In addition, survival outcomes were better in patients experiencing arthralgia/myalgia or dermatological toxicities.

CONCLUSION

This analysis indicated that, except for rare cases of nephrotoxicity, encorafenib+cetuximab is well tolerated in most patients, with most AEIs being mild-to-moderate in severity, occurring early and resolving rapidly.

CLINICAL TRIAL REGISTRATION

the BEACON study (ClinicalTrials.gov, NCT02928224; EudraCT, 2015-005805-35).

Resistance to targeted therapy in metastatic colorectal cancer: Current status and new developments

Colorectal cancer (CRC) is one of the most lethal and common malignancies in the world. Chemotherapy has been the conventional treatment for metastatic CRC (mCRC) patients. However, the effects of chemotherapy have been unsatisfactory. With the advent of targeted therapy, the survival of patients with CRC have been prolonged. Over the past 20 years, targeted therapy for CRC has achieved substantial progress. However, targeted therapy has the same challenge of drug resistance as chemotherapy. Consequently, exploring the resistance mechanism and finding strategies to address the resistance to targeted therapy, along with searching for novel effective regimens, is a constant challenge in the mCRC treatment, and it is also a hot research topic. In this review, we focus on the current status on resistance to existing targeted therapies in mCRC and discuss future developments.

Combined PD-1, BRAF and MEK inhibition in BRAFV600E colorectal cancer: a phase 2 trial

While BRAF inhibitor combinations with EGFR and/or MEK inhibitors have improved clinical efficacy in BRAFV600E colorectal cancer (CRC), response rates remain low and lack durability. Preclinical data suggest that BRAF/MAPK pathway inhibition may augment the tumor immune response. We performed a proof-of-concept single-arm phase 2 clinical trial of combined PD-1, BRAF and MEK inhibition with sparatlizumab (PDR001), dabrafenib and trametinib in 37 patients with BRAFV600E CRC. The primary end point was overall response rate, and the secondary end points were progression-free survival, disease control rate, duration of response and overall survival. The study met its primary end point with a confirmed response rate (24.3% in all patients; 25% in microsatellite stable patients) and durability that were favorable relative to historical controls of BRAF-targeted combinations alone. Single-cell RNA sequencing of 23 paired pretreatment and day 15 on-treatment tumor biopsies revealed greater induction of tumor cell-intrinsic immune programs and more complete MAPK inhibition in patients with better clinical outcome. Immune program induction in matched patient-derived organoids correlated with the degree of MAPK inhibition. These data suggest a potential tumor cell-intrinsic mechanism of cooperativity between MAPK inhibition and immune response, warranting further clinical evaluation of optimized targeted and immune combinations in CRC. ClinicalTrials.gov registration: NCT03668431.

Novel prognostic implications of complement activation in the tumour microenvironment for de novo metastatic BRAF V600E mutant colorectal cancer

BACKGROUND

Prognosis of metastatic BRAF V600E mutant colorectal cancer (CRC) is poor, and the prognostic implications of immune contextures in the tumour microenvironment (TME) for CRC remain elusive.

METHODS

We collected the primary tumour specimens and clinicopathological characteristics of patients with de novo metastatic microsatellite-stable BRAF V600E mutant CRC from two medical centres. Gene expression analysis was performed using the nCounterⓇ PanCancer Immune Profiling Panel. The Cox proportional hazards regression model was used for analysing survival outcomes in association with immune gene expression and immune cells. Our complement score was defined on the basis of the average gene expression in the selected co-expression module.

RESULTS

High expression of classical and regulatory complement genes was significantly associated with poor prognosis (N = 54). A high complement score (defined as a score above the median value) indicated significantly shorter survival. The overall survival (OS) impact of the high score remained significant in multivariate analyses. Additionally, our complement score was strongly correlated with C4d expression in immunohistochemical staining and tumour-associated macrophage (TAM) M2 signatures.

CONCLUSIONS

Complement activation in the TME was significantly associated with poor OS and was correlated with TAM M2 in patients with de novo metastatic BRAF V600E mutant CRC.

Targeting BRAF V600E in metastatic colorectal cancer: where are we today?

Colorectal cancer (CRC) is the second most frequent cause of direct cancer death worldwide. The study of the molecular state of oncogenes has predictive and prognostic value in metastatic CRC (mCRC). The B-raf proto-oncogene (BRAF) gene mutation represents the 8%-12% of all mutations in mCRC. The BRAF V600E mutation, considered the most common alteration of BRAF, corresponds to a constitutive kinase with a high activating capacity of the RAS/RAF/MEK/ERK pathway after a cascade of successive phosphorylations in the transcription of genes. BRAF V600E mutation is more prevalent in women, elderly, right-sided colon cancer and Caucasian population. Unfortunately, it is considered a poor predictive and prognosis biomarker. Patients with mCRC BRAF V600E mutated (BRAFm) are generally associated with poor response to chemotherapy and short progression-free survival and overall survival. Recently, randomised clinical trials have studied the combination of different chemotherapy regimens with angiogenic inhibitors in mCRC BRAFm. In addition, new anti-BRAF and immunotherapy agents have also been studied in this population, with positive results. The objective of this review is to acknowledge the biology and molecular pathway of BRAF, critically analyse the clinical trials and the therapy options published until today and evaluate the options of treatment according to the patient's clinical presentation.

Identification of GINS1 as a therapeutic target in the cancer patients infected with COVID-19: a bioinformatics and system biology approach

BACKGROUND

Coronavirus disease 2019 (COVID-19) caused a series of biological changes in cancer patients which have rendered the original treatment ineffective and increased the difficulty of clinical treatment. However, the clinical treatment for cancer patients infected with COVID-19 is currently unavailable. Since bioinformatics is an effective method to understand undiscovered biological functions, pharmacological targets, and therapeutic mechanisms. The aim of this study was to investigate the influence of COVID-19 infection in cancer patients and to search the potential treatments.

METHODS

Firstly, we obtained the COVID-19-associated genes from seven databases and analyzed the cancer pathogenic genes from Gene Expression Omnibus (GEO) databases, respectively. The Cancer/COVID-19-associated genes were shown by Venn analyses. Moreover, we demonstrated the signaling pathways and biological functions of pathogenic genes in Cancer/COVID-19.

RESULTS

We identified that Go-Ichi-Ni-San complex subunit 1 (GINS1) is the potential therapeutic target in Cancer/COVID-19 by GEPIA. The high expression of GINS1 was not only promoting the development of cancers but also affecting their prognosis. Furthermore, eight potential compounds of Cancer/COVID-19 were identified from CMap and molecular docking analysis.

CONCLUSION

We revealed the GINS1 is a potential therapeutic target in cancer patients infected with COVID-19 for the first time, as COVID-19 will be a severe and prolonged pandemic. However, the findings have not been verified actually cancer patients infected with COVID-19, and further studies are needed to demonstrate the functions of GINS1 and the clinical treatment of the compounds.

WJOG13219G: The Efficacy and Safety of FOLFOXIRI or Doublet plus Anti-VEGF Therapy in Previously Untreated BRAFV600E Mutant Metastatic Colorectal Cancer: A Multi-Institutional Registry-Based Study (BRACELET Study)

BACKGROUND

The real-world survival benefit of FOLFOXIRI (fluorouracil, leucovorin, oxaliplatin, and irinotecan) plus anti-VEGF therapy (Triplet) over doublet chemotherapy (Doublet) remains controversial in patients with BRAF^V600E mutant metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

WJOG13219G was a multicenter, retrospective, registry-based study of patients with BRAF^V600E mutant mCRC who received first-line triplet or doublet chemotherapy from January 2014 to December 2019 in Japan. Inverse probability of treatment weighting (IPTW) was used to adjust for patient background.

RESULTS

The analysis included 79 and 91 patients in the Triplet and Doublet groups, respectively. The Triplet group was significantly younger and had better performance status. No statistical difference was noted in progression-free survival (PFS; HR, 0.82; 95% CI, 0.60-1.13; P = .22) and overall survival (OS; HR, 0.88; 95% CI, 0.62-1.25; P = .48) between both groups. IPTW analysis also showed no difference between the 2 groups in PFS (HR, 0.86; 95% CI, 0.69-1.08; P = .20) and OS (HR, 0.93; 95% CI, 0.73-1.20; P = .59). The Triplet and Doublet groups had an objective response rate of 53% and 41%, respectively (P = .10). At least one grade 3 or 4 adverse event was seen in 51 (65%) and 43 (47%) patients in the Triplet and Doublet groups, respectively, with the incidence of neutropenia being significantly higher in the former.

CONCLUSION

Triplet therapy had no survival benefit versus doublet therapy in the overall and IPTW cohorts or specific subgroups for real-world patients with BRAF^V600E mutant mCRC.