Targeting BRAF in metastatic colorectal cancer: Maximizing molecular approaches

Penile metastasis from colon cancer with BRAF V600E mutation treated with BRAF/MEK-targeted therapy plus cetuximab: A case report

BACKGROUND

The incidence of colon cancer has been progressively increasing over time, whereas penile metastasis of colon cancer has remained exceedingly uncommon. Since the prognosis for colon cancer with BRAF V600E mutation is relatively unfavorable, further exploration and investigation are still required to develop treatment strategies for such rare cases.

CASE SUMMARY

About one year after surgery and chemotherapy, a 50-year-old patient with sigmoid colon cancer developed a mass at the base of the patient's penis, accompanied by severe tenderness and pain during urination. With disease progression, multiple metastatic nodules also emerged in other regions of the penis, including the coronal sulcus. The nodules located in the coronal sulcus were excised for histopathological examination. The histopathological findings revealed that the nodules were metastases originating from the sigmoid colon cancer, with a BRAF V600E mutation detected. This prompted a modification of the therapy regimen of cetuximab, dabrafenib and trametinib, which effectively held back the progression of penile metastasis in the patient.

CONCLUSION

Combining the BRAF/MEK-targeted therapy with cetuximab demonstrates a favorable therapeutic response in BRAF V600E-mutated colon cancer with penile metastasis.

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.

Computed tomography-based radiomics nomogram for the pre-operative prediction of BRAF mutation and clinical outcomes in patients with colorectal cancer: a double-center study

OBJECTIVE

To develop and validate a radiomics nomogram based on CT for the pre-operative prediction of BRAF mutation and clinical outcomes in patients with colorectal cancer (CRC).

METHODS

A total of 451 CRC patients (training cohort = 190; internal validation cohort = 125; external validation cohort = 136) from 2 centers were retrospectively included. Least absolute shrinkage and selection operator regression was used to select radiomics features and the radiomics score (Radscore) was calculated. Nomogram was constructed by combining Radscore and significant clinical predictors. Receiver operating characteristic curve analysis, calibration curve and decision curve analysis were used to evaluate the predictive performance of the nomogram. Kaplan‒Meier survival curves based on the radiomics nomogram were used to assess overall survival (OS) of the entire cohort.

RESULTS

The Radscore consisted of nine radiomics features which were the most relevant to BRAF mutation. The radiomics nomogram integrating Radscore and clinical independent predictors (age, tumor location and cN stage) showed good calibration and discrimination with AUCs of 0.86 (95% CI: 0.80-0.91), 0.82 (95% CI: 0.74-0.90) and 0.82 (95% CI: 0.75-0.90) in the training cohort, internal validation and external validation cohorts, respectively. Furthermore,the performance of nomogram was significantly better than that of the clinical model (p < 0.05). The radiomics nomogram-predicted BRAF mutation high-risk group had a worse OS than the low-risk group (p < 0.0001).

CONCLUSION

The radiomics nomogram showed good performance in predicting BRAF mutation and OS of CRC patients, which could provide valuable information for individualized treatment.

ADVANCES IN KNOWLEDGE

The radiomics nomogram could effectively predict BRAF mutation and OS in patients with CRC. High-risk BRAF mutation group identified by the radiomics nomogram was independently associated with poor OS.

Conversion Surgery After Encorafenib Plus Cetuximab for Chemorefractory BRAF V600E-mutated Colorectal Cancer With Para-aortic Lymph Node Metastases

BACKGROUND/AIM

Mutant BRAF V600E colorectal cancer accounts for 5% of metastatic colorectal cancers, and it has a poor response to systemic chemotherapy and a poor prognosis. However, combination treatment involving MAPK pathway blockade is effective for this cancer. Herein, we report a case of a patient who underwent conversion surgery after encorafenib plus cetuximab for chemorefractory BRAF V600E-mutated colorectal cancer with para-aortic lymph node metastases.

CASE REPORT

A 68-year-old woman was diagnosed with ascending colon cancer and multiple para-aortic lymph node metastases. After primary tumor resection, molecular genetic testing of the primary tumor revealed a BRAF V600E mutation. She was treated with FOLFOXIRI plus bevacizumab as first-line chemotherapy. After disease progression, the regimen was changed to encorafenib plus cetuximab, and the metastatic lesions shrank. She underwent para-aortic lymph node dissection as conversion surgery, and pathology revealed complete response of the lymph nodes. She achieved long-term survival.

CONCLUSION

The development of new treatments for BRAF V600E-mutated metastatic colorectal cancer will increase opportunities for conversion therapy.

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.

Melanogenesis and the Targeted Therapy of Melanoma

Pigment production is a unique character of melanocytes. Numerous factors are linked with melanin production, including genetics, ultraviolet radiation (UVR) and inflammation. Understanding the mechanism of melanogenesis is crucial to identify new preventive and therapeutic strategies in the treatment of melanoma. Here, we reviewed the current available literatures on the mechanisms of melanogenesis, including the signaling pathways of UVR-induced pigment production, MC1R's central determinant roles and MITF as a master transcriptional regulator in melanogenesis. Moreover, we further highlighted the role of targeting BRAF, NRAS and MC1R in melanoma prevention and treatment. The combination therapeutics of immunotherapy and targeted kinase inhibitors are becoming the newest therapeutic option in advanced melanoma.

BRAF Mutations in Colorectal Liver Metastases: Prognostic Implications and Potential Therapeutic Strategies

Simple Summary

In this literature review, we investigated the relationship between BRAF mutation and prognosis in patients with colorectal cancer liver metastases. We also investigated factors affecting the prognosis of patients with BRAF mutations and summarized the latest research on targeted therapies.

Abstract

Surgery combined with chemotherapy and precision medicine is the only potential treatment for patients with colorectal cancer liver metastases (CRLM). The use of modern molecular biotechnology to identify suitable biomarkers is of great significance for predicting prognosis and formulating individualized treatment plans for these patients. BRAF mutations, particularly V600E, are widely believed to be associated with poor prognosis in patients with metastatic CRC (mCRC). However, it is unclear which specific factors affect the prognosis of CRLM patients with BRAF mutations. It is also unknown whether patients with resectable CRLM and BRAF mutations should undergo surgical treatment since there is an increased recurrence rate after surgery in these patients. In this review, we combined the molecular mechanism and clinical characteristics of BRAF mutations to explore the prognostic significance and potential targeted therapy strategies for patients with BRAF-mutated CRLM.

Prognostic and predictive molecular biomarkers in advanced colorectal cancer

The revolution of precision medicine has produced unprecedented seismic shifts in the treatment paradigm of advanced cancers. Among the major killers, colorectal cancer (CRC) is far behind the others. In fact, the great successes obtained in breast, NSCLC, melanoma, and genitourinary tract tumors have been observed only in fewer than 5 % metastatic colorectal cancer (mCRC): those with the mismatch repair deficiency (dMMR), a well-known predictive factor for to the outstanding efficacy of checkpoint inhibitors (CPI). The treatment of the remaining vast majority mCRC patients is still based upon only two molecular determinants: the RAS and BRAF mutational status. New promising biomarkers include HER2, tumor mutational burden (TMB) for its possible implications on CPI efficacy, and the extremely rare NTRK fusions. The Consensus Molecular Subtypes classification (CMS) is a good example of the efforts to combine different molecular features of this disease, although its relevance in clinical practice is still under investigation. In this Review, we focus on all these prognostic and predictive biomarkers, analyzing data from the most important clinical trials of the last years. We also try to rank them according to their prognostic and predictive power.

Qingjie Fuzheng Granule Inhibits EMT and Induces Autophagy in Colorectal Cancer via mTOR Signaling Pathways

Qingjie Fuzheng granule (QFG) is a traditional Chinese medicinal formula used extensively as an alternative medicine for cancer treatment, including colorectal cancer (CRC). But its pathological mechanism in CRC is unclear. To study antitumor treatment effects and mechanisms of QFG, we established a CRC HCT-116 xenograft mouse model and assessed QFG on EMT and autophagy progression in vivo. The mice were randomly divided into 2 groups (n = 10 each group) and treated with intragastric administration of 1 g/kg of QFG or saline 6 days a week for 28 days (4 weeks). Body weight was measured every other day with electronic balance. At the end of the treatment, the tumor weight was measured. Immunohistochemical (IHC) and western blot (WB) assay were used to detect the expression level of E-cadherin, N-cadherin, vimentin, and TWIST1 to evaluate the effect of QFG on tumor cell EMT progression. IHC and WB assay were also used to detect the expression level of beclin-1, LC3-II, and p62 to evaluate the effect of QFG on tumor cell autophagy progression. Furthermore, the expression level of relative proteins in mTOR pathway was detected by WB assay to investigate the mechanism of QFG effect on CRC. We discovered that QFG inhibited the rise of tumor weight while it had no effect on mice body weight, which proved that QFG could inhibit CRC growth progression without significant side effects in vivo. In addition, QFG treatment inhibited EMT and induced autophagy progression in CRC tumor cells, including that QFG upregulated the expression of E-cadherin, beclin-1, and LC3-II, but downregulated the expression of N-cadherin, vimentin, TWIST1, and p62. And, QFG decreased the ratio of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR, but increased the ratio of p-AMPK/AMPK. All findings from this research proved that QFG can induce autophagy and inhibit EMT progression in CRC via regulating the mTOR signaling pathway.

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.

Predictive and prognostic biomarkers with therapeutic targets in colorectal cancer: A 2021 update on current development, evidence, and recommendation

Although therapeutically actionable molecular alterations are widely distributed across many cancer types, only a handful of them show evidence of clinical utility and are recommended for routine clinical practice in the management of cancers of colon and rectum (CRC). This 2021 update aims to provide a succinct summary on the use of prognostic and/or predictive biomarkers (expanded RAS, BRAF, microsatellite-high [MSI-H] or deficient mismatch repair [dMMR], neurotrophic tyrosine receptor kinase [NTRK] fusion genes, and human epidermal growth factor receptor type II [HER2] gene amplification) associated with CRC. Therapeutic implications of each relevant predictive or prognostic biomarker for patients with CRC are described, along with discussion on new developments on (1) biomarker-driven therapies such as testing of BRAF, MLH1 promoter methylation and MMR germline genes in differentiating sporadic CRC or hereditary conditions such as Lynch syndrome; (2) first-line use of immune checkpoint inhibitors in metastatic CRC; (3) risk stratification and therapy selection based on primary tumor location (left-sided vs. right-sided colon cancer); (3) atypical BRAF mutations; (4) use of EGFR directed therapy in the perioperative oligometastatic disease setting; (5) re-challenge of EGFR directed therapy and (6) personalizing therapy of fluoropyrimidine and irinotecan based on new evidence in pharmacogenomic testing. Data are collected and analyzed from available systematic reviews and meta-analyses of treatments with known therapeutic targets in CRC, which may be associated with predictive and/or prognostic biomarkers. Discussions are presented in an application-based format, with goal to empower pharmacists or other clinicians to gain awareness and understanding in biomarker-driven cancer therapy issues.

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.

Circulating lncRNA DANCR as a potential auxillary biomarker for the diagnosis and prognostic prediction of colorectal cancer

Studies have shown that long non-coding RNAs (lncRNAs) play vital roles in the development of cancer, including colorectal cancer (CRC). Our purpose is to validate the diagnostic value of serum differentiation antagonizing non-protein coding RNA (DANCR) in CRC by focusing on its expression and clinical application. lncRNA expression profiles of CRC patients were obtained and analyzed by repurposing the publically available microarray data. Tissue or serum specimens were obtained from 40 patients with primary CRC, 10 patients with recurrent CRC, 40 patients with colorectal polyps, and 40 healthy controls. It was found that DANCR level in the CRC tissue and serum was significantly increased, and serum DANCR expression was decreased in post-operative patients as compared with that in pre-treatment patients and recurrent patients. In addition, serum DANCR expression was significantly correlated with different TNM stages. Correlation analysis of DANCR and other diagnostic indicators showed that the serum DANCR expression level was significantly correlated with CA199 but not with CEA in CRC patients. As for diagnostic efficiency by ROC analysis, the area under the curve (AUC) of serum DANCR was higher than that of CEA and CA199 in CRC group vs. colorectal polyp group. Simultaneous detection of DANCR, CEA and CA199 yielded the highest sensitivity and AUC as compared with either of them alone. Taken together, serum DANCR was up-regulated in CRC patients and high expression of DANCR may prove to be a potential biomarker for the diagnosis of CRC.

UGT1A1 Polymorphism for Irinotecan Dose Escalation in Patients with BRAF-Mutated Metastatic Colorectal Cancer Treated with First-Line Bevacizumab and FOLFIRI

BACKGROUND

Patients with metastatic colorectal cancer (mCRC) and BRAF V600E mutation have a poor prognosis, with a median progression-free survival (PFS) of only 5-7 months after initial therapy. The current standard first-line chemotherapy for these patients includes FOLFOX or FOLFIRI plus bevacizumab. In this study, we explored the effects and oncological outcomes of UGT1A1 polymorphism for irinotecan escalation in patients with BRAF-mutated mCRC. Patients and Methods. This retrospective study included 17 patients with BRAF-mutated mCRC between April 2016 and December 2019. UGT1A1 genotyping was performed on all patients prior to initiating bevacizumab plus FOLFIRI chemotherapy. The primary endpoint was PFS, and the secondary endpoints were toxicity, response rate, disease control rate, and overall survival (OS).

RESULTS

Fifteen and two patients had UGT1A1 1∗/1∗ and 1∗/28∗, respectively. Eight underwent irinotecan dose escalation with tolerable adverse effects (AEs), and nine maintained an irinotecan dose of 180 mg/m2 or required deescalation to 150 mg/m2 due to intolerable AEs. After a median follow-up period of 15.7 (range, 3-54) months, the median PFS and OS were 9.4 and 15.7 months, respectively. Grade 3/4 AEs were observed in three (6%) patients. The disease control and partial response rates were 64.7% and 11.8%, respectively, indicating that most patients (14, 82.3%) could maintain this as a first-line line therapy with stable disease or proceed to second-line therapy if disease progression occurred, thereby maintaining acceptable performance status.

CONCLUSIONS

The oncological outcomes of patients with BRAF-mutated mCRC treated using FOLFIRI plus bevacizumab with irinotecan dose escalation as a first-line therapy are acceptable with tolerable AEs; this may be a feasible treatment option in such patients. Pretherapeutic UGT1A1 genotyping-guided dose adjustment can achieve favorable outcomes.

HER2 in metastatic colorectal cancer: a new to target to remember

Metastatic colorectal cancer is the second most common cause of cancer death. Standard chemotherapy in combination with targeted therapies represent the backbone for the treatment of advanced disease. However, options are limited for patients progressing on these regimens. Genetic testing can offer patients the opportunity to benefit from novel therapies, namely immune checkpoint inhibitors in microsatellite instability-positive tumors. HER2 overexpression has recently emerged as a potentially targetable tumor marker in colorectal cancer (CRC). Despite the absence of approvals for anti-HER2 therapies in CRC, many agents such as trastuzumab and pertuzumab were tested and demonstrated significant antitumor activity, even in heavily pretreated patients. Early trials are also evaluating lapatinib, T-DM1, tucatinib and other anti-HER2 agents in patients with metastatic CRC, with promising results.

The Role of Dynamic ctDNA Monitoring During Combination Therapies of BRAF V600E-Mutated Metastatic Colorectal Cancer: A Case Report

BACKGROUND

BRAF V600E mutation represents a group of colorectal carcinoma with poor prognosis. Although treatment strategies have been recommended after clinical investigations, the progression-free survival is short and unsatisfying.

CASE PRESENTATION

Here, we present the case of a 28-year-old male diagnosed with ascending colon adenocarcinoma with multiple liver metastases. Treatment with FOLFIRI plus cetuximab and vemurafenib achieved partial response, following which the patient received conversion surgery with clear resection margin. After disease recurrence, he received combination treatment of nivolumab and regorafenib. Until August 2020, the patient achieved a partial response with more than 12 months progression-free survival. Circulating tumor DNA (ctDNA) was monitored during the patient's treatment. His ctDNA fractions exhibited significant elevation two months before disease progression. As a comparison, the tumor markers were not elevated until the patient was confirmed PD through CT imaging.

CONCLUSION

This case exemplifies how liquid biopsy and ctDNA sequencing can aid in real-time molecular characterization of tumors.

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.

Phase I, Open-Label, Dose-Escalation/Dose-Expansion Study of Lifirafenib (BGB-283), an RAF Family Kinase Inhibitor, in Patients With Solid Tumors

PURPOSE

Lifirafenib is an investigational, reversible inhibitor of B-RAF^V600E, wild-type A-RAF, B-RAF, C-RAF, and EGFR. This first-in-human, phase I, dose-escalation/dose-expansion study evaluated the safety, tolerability, and efficacy of lifirafenib in patients with B-RAF– or K-RAS/N-RAS–mutated solid tumors.

METHODS

During dose escalation, adult patients with histologically/cytologically confirmed advanced solid tumors received escalating doses of lifirafenib. Primary end points were safety/tolerability during dose escalation and objective response rate in preselected patients with B-RAF and K-RAS/N-RAS mutations during dose expansion.

RESULTS

The maximum tolerated dose was established as 40 mg/d; dose-limiting toxicities included reversible thrombocytopenia and nonhematologic toxicity. Across the entire study, the most common grade ≥ 3 treatment-emergent adverse events were hypertension (n = 23; 17.6%) and fatigue (n = 13; 9.9%). One patient with B-RAF–mutated melanoma achieved complete response, and 8 patients with B-RAF mutations had confirmed objective responses: B-RAF^V600E/K melanoma (n = 5, including 1 patient treated with prior B-RAF/MEK inhibitor therapy), B-RAF^V600E thyroid cancer/papillary thyroid cancer (PTC; n = 2), and B-RAF^V600E low-grade serous ovarian cancer (LGSOC; n = 1). One patient with B-RAF–mutated non–small-cell lung cancer (NSCLC) had unconfirmed partial response (PR). Patients with K-RAS–mutated endometrial cancer and K-RAS codon 12–mutated NSCLC had confirmed PR (n = 1 each). No responses were seen in patients with K-RAS/N-RAS–mutated colorectal cancer (n = 20).

CONCLUSION

Lifirafenib is a novel inhibitor of key RAF family kinases and EGFR, with an acceptable risk-benefit profile and antitumor activity in patients with B-RAF^V600–mutated solid tumors, including melanoma, PTC, and LGSOC, as well as K-RAS–mutated NSCLC and endometrial carcinoma. Future comparisons with first-generation B-RAF inhibitors and exploration of lifirafenib alone or as combination therapy in patients with selected RAS mutations who are resistant/refractory to first-generation B-RAF inhibitors are warranted.

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.

LncRNA BANCR promotes tumorigenesis and enhances adriamycin resistance in colorectal cancer

Colorectal cancer (CRC) is the third most common malignancy in the United States. Chemotherapeutic resistance is a massive obstacle for cancer treatment. The roles and molecular basis of long non-coding RNA BRAF-activated noncoding RNA (BANCR) in CRC progression and adriamycin (ADR) resistance have not been extensively identified. In this study, we found that BANCR and CSE1L expressions were upregulated in CRC tumor tissues. Meanwhile, CSE1L expression was correlated with depth of CRC. BANCR silencing suppressed cell proliferation and invasion capacity, increased apoptotic rate and potentiated cell sensitivity to ADR. CSE1L downregulation triggered a reduction of cell proliferation and invasion ability, and an increase of apoptosis rate and cell sensitivity to ADR. CSE1L overexpression attenuated si-BANCR-mediated anti-proliferation, anti-invasion and pro-apoptosis effects in CRC cells. BANCR acted as a molecular sponge of miR-203 to sequester miR-203 away from CSE1L in CRC cells, resulting in the upregulation of CSE1L expression. CSE1L knockdown inhibited expressions of DNA-repair-related proteins (53BP1 and FEN1) in HCT116 cells. BANCR knockdown also inhibited tumor growth and enhanced ADR sensitivity in CRC mice model. In conclusion, BANCR knockdown suppressed CRC progression and strengthened chemosensitization of CRC cells to ADR possibly by regulating miR-203/CSE1L axis, indicating that BANCR might be a promising target for CRC treatment.

Cancer Treatment in the Genomic Era

The complexity of human cancer underlies its devastating clinical consequences. Drugs designed to target the genetic alterations that drive cancer have improved the outcome for many patients, but not the majority of them. Here, we review the genomic landscape of cancer, how genomic data can provide much more than a sum of its parts, and the approaches developed to identify and validate genomic alterations with potential therapeutic value. We highlight notable successes and pitfalls in predicting the value of potential therapeutic targets and discuss the use of multi-omic data to better understand cancer dependencies and drug sensitivity. We discuss how integrated approaches to collecting, curating, and sharing these large data sets might improve the identification and prioritization of cancer vulnerabilities as well as patient stratification within clinical trials. Finally, we outline how future approaches might improve the efficiency and speed of translating genomic data into clinically effective therapies and how the use of unbiased genome-wide information can identify novel predictive biomarkers that can be either simple or complex.

Qingjie Fuzheng granules inhibit colorectal cancer cell growth by the PI3K/AKT and ERK pathways

BACKGROUND

Qingjie Fuzheng granules (QFGs) are part of a traditional Chinese medicine formula, which has been widely used and found to be clinically effective with few side effects in various cancer treatments, including colorectal cancer (CRC). However, the precise mechanisms and molecular signaling pathways involved in the activity of QFGs' anticancer effect have not been reported in the literature. In this study, we hypothesized that QFGs can inhibit the growth of colorectal cancer cells, and that its mechanism is closely related to one or more intracellular signal transduction pathways.

AIM

To better evaluate the mechanism underlying the anti-cancer effect of QFGs on the CRC cell lines HCT-116 and HCT-8.

METHOD

First, we measured cell viability and cytotoxicity by performing MTT and lactate dehydrogenase (LDH) assays. We evaluated the role of QFGs in cell proliferation and apoptosis by assessing colony formation and analyzing Hoechst 33258 staining. Second, cell cycle and apoptosis rates were measured by fluorescence activated cell sorting, and the expression levels of survivin, cyclin D1, CDK4, p21, Bax, Bcl-2, Fas, FasL, and cleaved-caspase-3/-8/-9 were measured by performing western blots and caspase activity assays. Furthermore, inhibitors of caspase-3/-8/-9 were used to elucidate the specific apoptosis pathway induced by QFGs in cancer cells. Finally, activation of the PI3K/AKT and ERK signaling pathways was examined using the western blot assay to investigate the possible mechanism.

RESULTS

MTT and LDH assays revealed that after 0.5-2.0 mg/mL of QFGs treatment, cell viability was reduced by (6.90% ± 1.03%)-(59.70% ± 1.51%) (HCT-116; P < 0.05) and (5.56% ± 4.52%)-(49.44% ± 2.47%) (HCT-8; P < 0.05), and cytotoxicity was increased from 0.52 ± 0.023 to 0.77 ± 0.002 (HCT-116; P < 0.01) and from 0.56 ± 0.054 to 0.81 ± 0.044 (HCT-8; P < 0.01) compared with the non-QFGs treatment groups. Additionally, colony formation and Hoechst 33258 staining assays showed that QFGs inhibited proliferation and induced apoptosis in CRC cells. QFGs also increased the expression levels of Bax, Fas and FasL, decreased the level of Bcl-2, and stimulated the activation of caspase-3/-8/-9, which were revealed by western blot and caspase activity assays. In contrast, when adding the three caspase inhibitors, the suppression effect of QFGs on cell viability and apoptosis were markedly inhibited. Moreover, QFGs suppressed the phosphorylation levels of PI3K, AKT and ERK.

CONCLUSION

These results demonstrated that QFGs can inhibit CRC cell proliferation and induce apoptosis by suppressing the PI3K/AKT and ERK signaling pathways.

Adefovir dipivoxil sensitizes colon cancer cells to vemurafenib by disrupting the KCTD12-CDK1 interaction

Vemurafenib is a B-Raf V600E inhibitor that exerts significant inhibitory effects in melanoma but not in colon cancer, and the mechanism of vemurafenib resistance remains unclear. In this study, bioinformatics analysis of gene profiles in cancer cells treated with vemurafenib or its analog revealed that cell cycle progression is significantly affected by vemurafenib. We found that CDK1 is stably activated in the vemurafenib-resistant (VR) colon cancer sublines that we established, indicating that CDK1 activation is responsible for vemurafenib resistance. As the KCTD12-CDK1 interaction is necessary for CDK1 activation, we screened an FDA-approved drug library consisting of 616 compounds and identified that adefovir dipivoxil (AD), a nucleoside analog for treatment of HBV infections, disrupts the CDK1-KCTD12 interaction and induces G2 phase arrest in the cell cycle. Functional assays demonstrated that AD significantly inhibited colon cancer cell proliferation and tumorigenesis both in vitro and in vivo with no observed side effects. Furthermore, AD sensitized vemurafenib-resistant colon cancer cells and tumor xenografts to vemurafenib. This study reveals that CDK1 activation induces vemurafenib resistance and that AD is a promising therapeutic strategy for colon cancer both as a single agent and in combination with vemurafenib.

Drug Sensitivity Screening and Targeted Pathway Analysis Reveal a Multi-Driver Proliferative Mechanism and Suggest a Strategy of Combination Targeted Therapy for Colorectal Cancer Cells

Treatment of colorectal cancer mostly relies on traditional therapeutic approaches, such as surgery and chemotherapy. Limited options of targeted therapy for colorectal cancer narrowly focus on blocking cancer-generic targets VEGFR and EGFR. Identifying the oncogenic drivers, understanding their contribution to proliferation, and finding inhibitors to block such drivers are the keys to developing targeted therapy for colorectal cancer. In this study, ten colorectal cancer cell lines were screened against a panel of protein kinase inhibitors blocking key oncogenic signaling pathways. The results show that four of the 10 cell lines did not respond to any kinase inhibitors significantly, the other six were mildly inhibited by AZD-6244, BMS-754807, and/or dasatinib. Mechanistic analyses demonstrate that these inhibitors independently block the MAP kinase pathway, IR/IGF-1R/AKT pathway, and Src kinases, suggesting a multi-driver nature of proliferative signaling in these cells. Most of these cell lines were potently and synergistically inhibited by pair-wise combinations of these drugs. Furthermore, seven of the 10 cell lines were inhibited by the triple combination of AZD-6244/BMS-754807/dasatinib with IC₅₀’s between 10 and 84 nM. These results suggest that combination targeted therapy may be an effective strategy against colorectal cancer.

Complete response with fluorouracil and irinotecan with a BRAFV600E and EGFR inhibitor in BRAF-mutated metastatic colorectal cancer: a case report

BACKGROUND

Patients with BRAF (v-Raf murine sarcoma viral oncogene homolog B) V600E-mutated metastatic colorectal cancer (mCRC) have a poor prognosis. The Southwest Oncology Group (SWOG) 1406 study evaluated the efficacy of vemurafenib in combination with irinotecan and cetuximab for simultaneous inhibition of epidermal growth factor receptor (EGFR) and BRAF in patients with BRAFV600E-mutated mCRC. Although the combination achieved higher progression-free survival (PFS) and disease control rates (DCRs), there was no complete response (CR) for the drug combination. In this case report, we report the complete recession of metastasis in a patient treated with irinotecan, cetuximab, vemurafenib, and 5-fluorouracil.

CASE PRESENTATION

A 44-year-old male patient with hepatitis B was diagnosed with right-sided colon adenocarcinoma. He was treated with capecitabine plus oxaliplatin as postoperative adjuvant chemotherapy for eight cycles with a disease-free survival (DFS) of 1 year before the emergence of peritoneal and pelvic metastases. BRAFV600E mutation was positive and chemotherapy included 12 courses of 5-fluorouracil, vemurafenib, irinotecan, and cetuximab. Complete response with recession of metastases was observed.

CONCLUSION

The combination of fluorouracil and irinotecan with a BRAFV600E and EGFR inhibitor may have synergistic action, leading to recession of secondary metastases in patients with BRAFV600E-mutated colorectal cancer.

Targeted Therapy for Colorectal Cancers With Non-V600 BRAF Mutations: Perspectives for Precision Oncology

BRAF mutations are found in up to 10% of colorectal cancers (CRC). Whereas the majority of BRAF mutant CRCs harbor V600 mutations, up to 25% express non-V600 BRAF mutations. It has been established that BRAF V600E mutations in CRC predict unresponsiveness to epidermal growth factor receptor (EGFR) inhibition—cetuximab and/or panitumumab—as a result of the constitutive activation of the mitogen-activated protein kinase pathway downstream of EGFR signaling. As more centers begin using next-generation sequencing assays to detect BRAF mutations, oncologists are more frequently confronted with treating patients with non-V600 BRAF mutations. In many instances, clinicians may be hesitant to use EGFR inhibitors for these patients, as it is largely assumed that tumors with non-V600 BRAF mutations activate the mitogen-activated protein kinase pathway in a similar manner to RAS or BRAF V600E mutations and would therefore be equally refractory to EGFR inhibition; however, the evidence that currently exists to substantiate this claim is mixed and incomplete. Recent data demonstrate that non-V600 BRAF mutant CRC is a distinct clinical entity with a favorable prognosis compared with CRC with V600E mutations. Preclinical data and several case reports suggest that a subset of BRAF non-V600 mutations that impair the protein's kinase activity may in fact confer heightened sensitivity to EGFR inhibition because of dependency on upstream receptor tyrosine kinase signaling. This review summarizes the clinical characteristics and targeted therapy approaches for non-V600 BRAF mutant CRCs, speculates on the value of non-V600 BRAF mutations as predictive biomarkers of responsiveness to EGFR inhibitors, and highlights outstanding questions in this emerging area of precision oncology.

Long non-coding RNA TP73-AS1 sponges miR-194 to promote colorectal cancer cell proliferation, migration and invasion via up-regulating TGFα

OBJECTIVE

Colorectal cancer (CRC) is the 3rd most common cancer worldwide. Recently, long non-coding RNAs (lncRNAs) were found to be critical modulators in the CRC progression. The aim of this study is to investigate the potential roles of lncRNA P73 antisense RNA 1T (TP73-AS1) in CRC development and progression.

METHODS

Quantitative real-time PCR (qRT-PCR) was performed to determine relevant gene expression levels; western blot was performed to determine protein expression levels; CCK-8, colony formation, wound healing and Transwell invasion assays were used to determined CRC cell proliferation, migration and invasion; in vivo tumor growth was assessed in xenograft mice model.

RESULTS

TP73-AS1 was up-regulated in both CRC tissues and CRC cell lines. Overexpression of TP73-AS1 was associated with metastasis and advanced clinical stages in CRC patients. Overexpression of TP73-AS1 promoted CRC cell growth, proliferation, migration and invasion in vitro; and knockdown of TP73-AS1 significantly inhibited CRC cell growth, proliferation, migration and invasion in vitro as well as tumor growth in vivo. Bioinformatics analysis and luciferase reporter assay indicated that TP73-AS1 could bind directly with miR-194, and TP73-AS1 negatively regulated the expression of miR-194 in CRC cells. Further study indicated that miR-194 negatively regulated the downstream target of transforming growth factor alpha (TGFα) via targeting its 3' untranslated region, and TP73-AS1 positively regulated the expression of TGFα in CRC cells. Moreover, overexpression of miR-194 suppressed CRC cell proliferation and invasion, and attenuated the effects of TP73-AS1 overexpression on CRC cell proliferation and invasion. Silence of TGFα inhibited CRC cell proliferation and invasion, and also reversed the effects of TP73-AS1 overexpression on CRC cell proliferation and invasion.

CONCLUSIONS

this study demonstrated that TP73-AS1 regulated CRC progression by acting as a competitive endogenous RNA to sponge miR-194 to modulate the expression of TGFα.

Synthesis and Biological Evaluation of New Madecassic Acid Derivatives Targeting ERK Cascade Signaling

In the present study, a series of novel madecassic acid derivatives was synthesized and screened against the National Cancer Institute's 60 human cancer cell line panel. Among them, compounds 5, 12, and 17 displayed potent and highly differential antiproliferative activity against 80% of the tumor cells harboring the B-Raf^V600E mutation within the nanomolar range. Structure-activity analysis revealed that a 5-membered A ring containing an α,β-unsaturated aldehyde substituted at C-23 with a 2-furoyl group seems to be crucial to produce this particular growth inhibition signature. In silico analysis of the cytotoxicity pattern of these compounds identified two highly correlated clinically approved drugs with known B-Raf^V600E inhibitory activity. Follow-up analysis revealed inhibition of the ERK signaling pathway through the reduction of cellular Raf protein levels is a key mechanism of action of these compounds. In particular, 17 was the most potent compound in suppressing tumor growth of B-Raf^V600E-mutant cell lines and displayed the highest reduction of Raf protein levels among the tested compounds. Taken together, this study revealed that modifications of madecassic acid structure can provide molecules with potent anticancer activity against cell lines harboring the clinically relevant B-Raf^V600E mutation, with compound 17 identified as a promising lead for the development of new anticancer drugs.

When Tissue Is No Longer the Issue: Tissue-Agnostic Cancer Therapy Comes of Age

Matching unique features of cancer types with effective therapies is a cornerstone of precision medicine. Clinical success has been seen in inhibiting specific molecular alterations that drive the growth of cancer cells and targeting molecules whose elevated expression is confined to cancer cells. In addition, cancer cells can have vulnerabilities induced by somatic mutations they carry; attacks on these vulnerabilities range from specific molecular alterations pointing to direct drug strategies to harnessing immune recognition of genetically altered epitopes produced by the cancer cells. Recent advances have found that the success of biomarker-driven cancer therapy may be relevant across sites of origin. For example, cancer types that show DNA mismatch repair deficiency, such as colon, biliary, and endometrial cancer, are more sensitive to immune checkpoint inhibition. Several large, ongoing clinical trials with a "basket" design are combining tumor tissue genomics with potential off-the-shelf therapies in drug development, and more tissue-agnostic biomarker therapies are reaching the bedside.

How to find the right drug for each patient? Advances and challenges in pharmacogenomics

Cancer is a highly heterogeneous disease with complex underlying biology. For these reasons, effective cancer treatment is still a challenge. Nowadays, it is clear that a cancer therapy that fits all the cases cannot be found, and as a result the design of therapies tailored to the patient's molecular characteristics is needed. Pharmacogenomics aims to study the relationship between an individual's genotype and drug response. Scientists use different biological models, ranging from cell lines to mouse models, as proxies for patients for preclinical and translational studies. The rapid development of "-omics" technologies is increasing the amount of features that can be measured in these models, expanding the possibilities of finding predictive biomarkers of drug response. Finding these relationships requires diverse computational approaches ranging from machine learning to dynamic modeling. Despite major advances, we are still far from being able to precisely predict drug efficacy in cancer models, let alone directly on patients. We believe that the new experimental techniques and computational approaches covered in this review will bring us closer to this goal.

Genetic characterisation of molecular targets in carcinoma of unknown primary

BACKGROUND

Carcinoma of unknown primary (CUP) is a metastatic epithelial malignancy in the absence of an identifiable primary tumour. Prognosis for patients with CUP is poor because treatment options are generally limited to broad spectrum chemotherapy. A shift towards personalised cancer management based on mutation profiling offers the possibility of new treatment paradigms. This study has explored whether actionable, oncogenic driver mutations are present in CUP that have potential to better inform treatment decisions.

METHODS

Carcinoma of unknown primary cases (n = 21) were selected and DNA was isolated from formalin-fixed paraffin embedded sections prior to amplification and sequencing. Two distinct yet complementary targeted gene panels were used to assess variants in up to 76 known cancer-related genes for the identification of biologically relevant and actionable mutations.

RESULTS

Variants were detected in 17/21 cases (81%) of which 11 (52%) were potentially actionable with drugs currently approved for use in known primary cancer types or undergoing clinical trials. The most common variants detected were in TP53 (47%), KRAS (12%), MET (12%) and MYC (12%). Differences at the molecular level were seen between common CUP histological subtypes. CUP adenocarcinomas and poorly differentiated carcinomas harboured the highest frequency of variants in genes involved in signal transduction pathways (e.g. MET, EGFR, HRAS, KRAS, and BRAF). In contrast, squamous cell carcinoma exhibited a higher frequency of variants in cell cycle control and DNA repair genes (e.g. TP53, CDKN2A and MLH1).

CONCLUSION

Taken together, mutations in biologically relevant genes were detected in the vast majority of CUP tumours, of which half provided a potentially novel treatment option not generally considered in CUP.

Right Versus Left Colon Cancer: Resectable and Metastatic Disease

OPINION STATEMENT

Colorectal cancer does not represent a single anatomic entity and side of origin has a key impact on prognosis and response to different systemic therapies. Compared to tumours arising in left colon, right colorectal cancers rely on the activation of different molecular pathways (e.g. BRAF mutation and MSI status). From a clinical point of view, this results in a different response to anti-EGFR agents. Current guidelines suggest the use of cetuximab or panitumumab in RAS wild-type disease and left colon cancer especially for cytoreduction/conversion purposes, since the expected benefit in right colon cancer is absent or clinically modest. The prognostic role of microbiota in colorectal cancer disease deserves more clarification before being considered in common clinical practice. Screening policies could also be affected by these new acquisitions. At the moment, sidedness should be considered as a strong prognostic variable and a surrogate predictor of different activity of anti-EGFR agents in the metastatic setting. Its role in early stages of resected disease is still uncertain.

The Molecular Basis of Metastatic Colorectal Cancer

PURPOSE OF REVIEW

Metastatic colorectal cancer (CRC) is a vexing clinical problem. In contrast to early stage disease, once CRC metastasizes to other organs, long-term survival is compromised. We seek to review the molecular pathogenesis, animal models, and functional genomics for an enhanced understanding of how CRC metastasizes and how this can be exploited therapeutically.

RECENT FINDINGS

Mouse models may recapitulate certain aspects of metastatic human CRC and allow for studies to identify regulators of metastasis. Modulation of transcription factors, onco-proteins, or tumor suppressors have been identified to activate known metastatic pathways. CD44 variants, microRNAs and RNA binding proteins are emerging as metastatic modulators.

SUMMARY

CRC metastasis is a multi-faceted and heterogeneous disease. Despite common pathways contributing to metastatic development, there are numerous variables that modulate metastatic signals in subsets of patients. It is paramount that studies continue to investigate metastatic drivers, enhancers and inhibitors in CRC to develop therapeutic targets and improve disease outcomes.

Exploring the efficacy and cellular uptake of sorafenib in colon cancer cells by Raman micro-spectroscopy

This study demonstrates the efficacy and distribution of sorafenib in colon cancer cells by label-free Raman microscopy.