Clinicopathological relevance of BRAF mutations in human cancer. Pathology. 2013;45:346-356. [PMID: 23594689 DOI: 10.1097/pat.0b013e328360b61d]

Advancing targeted therapies in pancreatic cancer: Leveraging molecular abberrations for therapeutic success

Pancreatic cancer is one of the most deadly with poor prognosis and overall survival rate due to the dense stroma in the tumors which often is challenging for the delivery of drug to penetrate deep inside the tumor bed and usually results in the progression of cancer. The conventional treatment such as chemotherapy, radiotherapy or surgery shows a minimal benefit in the survival due to the drug resistance, poor penetration, less radiosensitivity or recurrence of tumor. There is an urgent demand to develop molecular-level targeted therapies to achieve therapeutic efficacy in the pancreatic ductal adenocarcinoma (PDAC) patients. The precision oncology focuses on the unique attributes of the patient such as epigenome, proteome, genome, microbiome, lifestyle and diet habits which contributes to promote oncogenesis. The targeted therapy helps to target the mutated proteins responsible for controlling growth, division and metastasis of tumor in the cancer cells. It is very important to consider all the attributes of the patient to provide the suitable personalized treatment to avoid any severe side effects. In this review, we have laid emphasis on the precision medicine; the utmost priority is to improve the survival of cancer patients by targeting molecular mutations through transmembrane proteins, inhibitors, signaling pathways, immunotherapy, gene therapy or the use of nanocarriers for the delivery at the tumor site. It will become beneficial therapeutic window to be considered for the advanced stage pancreatic cancer patients to prolong their survival rate.

Unraveling BRAF alterations: molecular insights to circumvent therapeutic resistance across cancer types

Aim: As intrinsic resistance - often driven by concurrent genomic alterations in tumor suppressor genes or oncogenes - remains a major challenge in oncology, this work aimed to comprehensively analyze BRAF somatic alterations across cancer types and identify new potential therapeutic strategies to overcome drug resistance. Methods: We conducted an extensive analysis of genomics, transcriptomics, and clinical data retrieved from public repositories, including cBioPortal. Our comprehensive analysis examined BRAF alterations [point mutations, structural variants (SVs) and copy number alteration] in more than 217,000 tumor samples across 120 distinct tumor types from primary and metastatic sites in both adult and pediatric cohorts, focusing on mutual exclusivity and co-occurrence of mutations in other oncogenes or tumor suppressors. The work also explores the association of BRAF somatic alterations with survival, clinical and molecular features. Results: Analysis of mutation frequencies across cancer types revealed that BRAFV600E represents approximately 90% of all BRAF alterations. While melanoma and thyroid carcinoma show the highest prevalence of BRAF mutations, followed by colorectal and non-small cell lung cancer in terms of absolute number of patients harboring BRAF mutations worldwide, notably high mutation frequencies were identified in rare malignancies, including hairy-cell leukemia, ganglioglioma, and serous borderline ovarian tumors. The comprehensive analysis of genomic profiling data across these tumors uncovered distinct patterns of co-occurring and mutually exclusive alterations in oncogenes and tumor suppressor genes, illuminating resistance mechanisms and suggesting novel therapeutic combinations. Conclusion: Comprehensive genomic profiling is critical for optimizing targeted therapy and overcoming drug resistance in BRAF-mutated cancers. The identification of co-occurring alterations provides opportunities for rational combination therapies, emphasizing the importance of detailed mutation profiling in developing effective treatment strategies across diverse cancer types.

A new broom sweeps clean: CLDN16 surpasses the BRAF-V600E mutation as an unrivaled biomarker in papillary thyroid cancer

OBJECTIVE

This study assessed CLDN16 as a potential replacement or improvement biomarker for papillary thyroid cancer (PTC), addressing the limitations associated with the prevalently used BRAF-V600E mutation.

DESIGN

Database analyses, tissue validation, RNA sequencing, and functional assays were conducted to evaluate CLDN16 as a PTC biomarker and its clinical application.

METHODS

CLDN16 expression was examined in PTC and normal thyroid/para-tumor tissues and compared across various cancer types. We evaluated diagnostic accuracy, stability in primary and metastatic sites, and associations with aggressive features. Knockdown experiments were performed to investigate the impact on PTC cell behavior. Additionally, we developed a support vector machine model for diagnosing malignant and high-risk PTCs.

RESULTS

CLDN16 demonstrated high specificity for PTC, with positive detection rates (88.0% in The Cancer Genome Atlas [TCGA] and 88.3% in our center) significantly surpassing BRAF-V600E (47.5% in TCGA and 74.3% in our center). This resulted in superior diagnostic accuracy (ROC-CLDN16 = 0.922 vs ROC-BRAF-V600E = 0.742 in TCGA). CLDN16 exhibited stable expression across primary and metastatic sites and was associated with aggressive features, including extrathyroidal extension and lymph node metastasis. CLDN16 knockdown inhibited migration, invasion, and iodine uptake in PTC cells. Clinically, CLDN16 effectively identified malignancy in BRAF wild patients (94.2%), and combined with BRAF-V600E, achieved 96.9% accuracy. The incorporation of CLDN16 into PTC molecular typing facilitated precise high-risk identification (92.0% accuracy in the training set and 100% in the validation set).

CONCLUSIONS

CLDN16 presents a promising biomarker that could surpass BRAF-V600E, offering effective clinical utility and revolutionizing PTC molecular typing for precise high-risk identification.

Epidemiology, survival and risk of subsequent primary malignancies in patients with digital papillary adenocarcinoma: a retrospective study of 213 patients in the Surveillance, Epidemiology, and End Results Program

Digital papillary adenocarcinoma (DPAc) is a rare and aggressive cutaneous malignancy of sweat gland derivation. We conducted a retrospective study of 213 patients with DPAc using the 17 registries of the Surveillance, Epidemiology, and End Results (SEER) Program. We estimated the incidence of DPAc to be 0.11 per million persons per year, with the incidence rising over the past two decades. Our study shows DPAc to most commonly affect White men, typically in their forties to sixties. We noted a 5-year disease-specific survival of 98.3% and 5-year overall survival of 95.7%. We also showed advanced age to be associated with more aggressive disease and identified tumour size as an independent risk factor affecting disease-specific survival. Our results also suggest that patients with DPAc have an elevated risk of developing subsequent primary malignancies, with men being at increased risk of developing lung/bronchial neoplasms and women being at increased risk of developing breast cancer.

Real-World Incidence of Incident Noninfectious Uveitis in Patients Treated With BRAF Inhibitors: A Nationwide Clinical Cohort Study

PURPOSE

To compare the incidence of noninfectious uveitis in skin melanoma or lung cancer patients who received BRAF inhibitors with that in those who received immune checkpoint inhibitors (ICIs) or conventional cytotoxic chemotherapy.

DESIGN

Nationwide population-based retrospective clinical cohort study METHODS: From the Health Insurance Review and Assessment Service database of South Korea, we retrospectively defined 77,323 patients with skin melanoma or lung cancer who received BRAF inhibitor therapy (BRAF inhibitor-exposed group; n = 396), ICIs (ICI-exposed group; n = 22,474), or conventional cytotoxic chemotherapy (unexposed group; n = 54,453). We calculated the 1-year cumulative incidence of noninfectious uveitis in each group from the first day of BRAF inhibitor, ICI, or cytotoxic agent administration.

RESULTS

During the first year of treatment initiation, the cumulative incidence of uveitis was 0.33%, 0.35%, and 2.27% in the unexposed, ICI-exposed, and BRAF inhibitor-exposed groups, respectively. Adjusted hazard ratios (aHR) indicated a 7.52-fold and 5.68-fold increased risk of uveitis in the BRAF inhibitor-exposed group compared with that in the unexposed and ICI-exposed groups (95% confidence interval [CI] 3.83-14.75, P < .001 and 95% CI 2.81-11.47, P < .001, respectively). After 1:4 propensity score matching, aHRs showed a 35.51-fold and 15.80-fold increased risk (95% CI 4.49-280.48, P = .001 and 95% CI 1.76-141.00, P = .014) of uveitis and severe uveitis, respectively, in the BRAF inhibitor-exposed versus unexposed patients. Crossover analysis within the BRAF inhibitor-exposed group showed a 3.71-fold increase in uveitis risk during 1-year post index date in comparison with 1-year prior to index date (95% CI 1.03-13.40, P = .046). In the BRAF inhibitor-exposed group, female sex, chronic kidney disease, and melanoma were associated with a trend of increased, albeit nonsignificant, risk of uveitis.

CONCLUSIONS

Melanoma or lung cancer patients treated with BRAF inhibitors showed significantly higher risk of noninfectious uveitis than patients treated with conventional cytotoxic drugs or ICIs. These findings emphasize the importance of pretreatment patient education on BRAF-inhibitor-associated uveitis risk to enable prompt ophthalmic evaluation and treatment if symptoms arise during drug administration.

BRAF mutation in myeloid neoplasm: incidences and clinical outcomes

The presence of BRAF mutation in hematological malignancies, excluding Hairy cell leukemia, and its significance as a driver mutation in myeloid neoplasms (MNs) remains largely understudied. This research aims to evaluate patient characteristics and outcomes of BRAF-mutated MNs. Among a cohort of 6667 patients, 48 (0.7%) had BRAF-mutated MNs. Notably, three patients exhibited sole BRAF mutation, providing evidence supporting the hypothesis of BRAF's role as a driver mutation in MNs. In acute myeloid leukemia, the majority of patients had secondary acute myeloid leukemia, accompanied by poor-risk cytogenic and RAS pathway mutations. Although the acquisition of BRAF mutation during disease progression did not correlate with unfavorable outcomes, its clearance through chemotherapy or stem cell transplant exhibited favorable outcomes (median overall survival of 34.8 months versus 10.4 months, p = 0.047). Furthermore, G469A was the most frequently observed BRAF mutation, differing from solid tumors and hairy cell leukemia, where V600E mutations were predominant.

The CpG Island Methylator Phenotype Status in Synchronous and Solitary Primary Colorectal Cancers: Prognosis and Effective Therapeutic Drug Prediction

Synchronous colorectal cancer (sCRC) is characterized by the occurrence of more than one tumor within six months of detecting the first tumor. Evidence suggests that sCRC might be more common in the serrated neoplasia pathway, marked by the CpG island methylator phenotype (CIMP), than in the chromosomal instability pathway (CIN). An increasing number of studies propose that CIMP could serve as a potential epigenetic predictor or prognostic biomarker of sCRC. Therapeutic drugs already used for treating CIMP-positive colorectal cancers (CRCs) are reviewed and drug selections for sCRC patients are discussed.

Effective Treatment of Lung Adenocarcinoma With a Novel SLC44A1-BRAF Fusion Using Pembrolizumab Followed by Trametinib: A Case Report

The serine-threonine protein kinase B-RAF (BRAF) fusions are rarely observed in non-small cell lung cancer (NSCLC) accounting for less than 1%, and therapeutic evidence for molecular-targeted drugs is lacking, unlike for BRAF V600E mutation by RAF and MEK inhibitors. A 75-year-old female patient with no smoking history and mild renal dysfunction developed recurrent lung adenocarcinoma and was initially treated with pembrolizumab immunotherapy followed by chemotherapy using docetaxel showing a certain efficacy but the disease finally progressed. Comprehensive genome profiling showed a novel SLC44A1-BRAF fusion and the tumor progression was controlled with the MEK inhibitor trametinib. Because of the rarity of NSCLC with BRAF fusion, the description of this case would be helpful for the treatment strategy for such tumors.

Neo-Darwinian Principles Exemplified in Cancer Genomics

Within the last two decades, the advent of next-generation sequencing accompanied by single-cell technologies has enabled cancer researchers to study in detail mutations and other genetic aberrations that transpire during transformation of cells to a neoplastic state. This article covers the insights gained through these extensive studies where neo-Darwinian principles can be inferred to play roles throughout neoplastic transformation. The cells promoted during cancer development exhibit cancer hallmarks combined with the related enabling characteristics as outlined by Hanahan and Weinberg, analogous to natural selection and survival of the fittest. Selection of driver mutations that inactivate proteins encoded by tumor suppressor genes differs in profound ways from mutations that activate tumor promoter proteins. In most cases, the later stages of cancer development are characterized by sudden, extensive damage to chromosomes in a process that is not Darwinian in nature. Nevertheless, cells that survive these cataclysmic events remain subject to Darwinian selection promoting clones exhibiting the greatest rates of progression. Duplications of chromosomal segments containing oncogenes, deletions of segments harboring tumor suppressor genes, or distinctive chromosomal rearrangements are often found in cells progressing into later stages of cancer. In summary, the technological developments in genome sequencing since the start of the century have given us clear insights into genomic alterations promoting tumor progression where neo-Darwinian mechanisms of clonal selection can be inferred to play a primary role.

Imidazopyridine-based kinase inhibitors as potential anticancer agents: A review

Considering the fundamental role of protein kinases in the mechanism of protein phosphorylation in critical cellular processes, their dysregulation, especially in cancers, has underscored their therapeutic relevance. Imidazopyridines represent versatile scaffolds found in abundant bioactive compounds. Given their structural features, imidazopyridines have possessed pivotal potency to interact with different protein kinases, inspiring researchers to carry out numerous structural variations. In this comprehensive review, we encompass an extensive survey of the design and biological evaluations of imidazopyridine-based small molecules as potential agents targeting diverse kinases for anticancer applications. We describe the structural elements critical to inhibitory potency, elucidating their key structure-activity relationships (SAR) and mode of actions, where available. We classify these compounds into two groups: Serine/threonine and Tyrosine inhibitors. By highlighting the promising role of imidazopyridines in kinase inhibition, we aim to facilitate the design and development of more effective, targeted compounds for cancer treatment.

Quinazolin-4-one/3-cyanopyridin-2-one Hybrids as Dual Inhibitors of EGFR and BRAFV600E: Design, Synthesis, and Antiproliferative Activity

A novel series of hybrid compounds comprising quinazolin-4-one and 3-cyanopyridin-2-one structures has been developed, with dual inhibitory actions on both EGFR and BRAFV600E. These hybrid compounds were tested in vitro against four different cancer cell lines. Compounds 8, 9, 18, and 19 inhibited cell proliferation significantly in the four cancer cells, with GI50 values ranging from 1.20 to 1.80 µM when compared to Doxorubicin (GI50 = 1.10 µM). Within this group of hybrids, compounds 18 and 19 exhibited substantial inhibition of EGFR and BRAFV600E. Molecular docking investigations provided confirmation that compounds 18 and 19 possess the capability to inhibit EGFR and BRAFV600E. Moreover, computational ADMET prediction indicated that most of the newly synthesized hybrids have low toxicity and minimal side effects.

Oncologic relevance of genetic alterations in sporadic synchronous and solitary colorectal cancer: a retrospective multicenter study

BACKGROUND

Oncologic impact of genetic alteration across synchronous colorectal cancer (CRC) still remains unclear. This study aimed to compare the oncologic relevance according to genetic alteration between synchronous and solitary CRC with performing systematic review.

METHODS

Multicenter retrospective analysis was performed for CRC patients with curative resection. Genetic profiling was consisted of microsatellite instability (MSI) testing, RAS (K-ras, and N-ras), and BRAF (v-Raf murine sarcoma viral oncogene homolog B1) V600E mutation. Multivariate analyses were conducted using logistic regression for synchronicity, and Cox proportional hazard model with stage-adjusting for overall survival (OS) and disease-free survival (DFS).

RESULTS

It was identified synchronous (n = 36) and solitary (n = 579) CRC with similar base line characteristics. RAS mutation was associated to synchronous CRC with no relations of MSI and BRAF. During median follow up of 77.8 month, Kaplan-meier curves showed significant differences according to MSI-high for OS, and in RAS, and BRAF mutation for DFS, respectively. In multivariable analyses, RAS and BRAF mutation were independent factors (RAS, HR = 1.808, 95% CI = 1.18-2.77, p = 0.007; BRAF, HR = 2.417, 95% CI = 1.32-4.41, p = 0.004). Old age was independent factor for OS (HR = 3.626, 95% CI = 1.09-12.00, p = 0.035).

CONCLUSION

This study showed that oncologic outcomes might differ according to mutation burden characterized by RAS, BRAF, and MSI between synchronous CRC and solitary CRC. In addition, our systematic review highlighted a lack of data and much heterogeneity in genetic characteristics and survival outcomes of synchronous CRC relative to that of solitary CRC.

Progress of research on molecular targeted therapies for colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies, accounting for approximately 10% of global cancer incidence and mortality. Approximately 20% of patients with CRC present metastatic disease (mCRC) at the time of diagnosis. Moreover, up to 50% of patients with localized disease eventually metastasize. mCRC encompasses a complex cascade of reactions involving multiple factors and processes, leading to a diverse array of molecular mechanisms. Improved comprehension of the pathways underlying cancer cell development and proliferation, coupled with the accessibility of relevant targeted agents, has propelled advancements in CRC treatment, ultimately leading to enhanced survival rates. Mutations in various pathways and location of the primary tumor in CRC influences the efficacy of targeted agents. This review summarizes available targeted agents for different CRC pathways, with a focus on recent advances in anti-angiogenic and anti-epidermal growth factor receptor agents, BRAF mutations, and human epidermal growth factor receptor 2-associated targeted agents.

Discovery of a highly potent pan-RAF inhibitor IHMT-RAF-128 for cancer treatment

Although rat sarcoma viral oncogene homolog (RAS) mutations occur in about 30% of solid tumors, targeting RAS mutations other than KRAS-G12C is still challenging. As an alternative approach, developing inhibitors targeting RAF, the downstream effector of RAS signaling, is currently one of the main strategies for cancer therapy. Selective v-raf murine sarcoma viral oncogene homolog B1 (BRAF)-V600E inhibitors Vemurafenib, Encorafenib, and Dabrafenib have been approved by FDA and received remarkable clinical responses, but these drugs are ineffective against RAS mutant tumors due to limited inhibition on dimerized RAF. In this study, we developed a highly potent pan-RAF inhibitor, IHMT-RAF-128, which exhibited similarly high efficacies in inhibiting both partners of the RAF dimer, and showed potent anti-tumor efficacy against a variety of cancer cells harboring either RAF or RAS mutations, especially Adagrasib and Sotorasib (AMG510) resistant-KRAS-G12C secondary mutations, such as KRAS-G12C-Y96C and KRAS-G12C-H95Q. In addition, IHMT-RAF-128 showed excellent pharmacokinetic profile (PK), and the bioavailability in mice and rats were 63.9%, and 144.1%, respectively. Furthermore, IHMT-RAF-128 exhibited potent anti-tumor efficacy on xenograft mouse tumor models in a dose-dependent manner without any obvious toxicities. Together, these results support further investigation of IHMT-RAF-128 as a potential clinical drug candidate for the treatment of cancer patients with RAF or RAS mutations.

Langerhans Cell Histiocytosis in Children: Literature Review

Relevant information on Langerhans cell histiocytosis development and course in children is presented. The current concepts of disease pathogenesis, principles of its severity evaluation, patients stratification into risk groups, as well as of clinical course features are described. Modern approaches to the disease treatment via targeted therapy are summarized and analyzed. 

The adaptor protein VEPH1 interacts with the kinase domain of ERBB2 and impacts EGF signaling in ovarian cancer cells

Upregulation of ERBB2 and activating mutations in downstream KRAS/BRAF and PIK3CA are found in several ovarian cancer histotypes. ERBB2 enhances signaling by the ERBB family of EGF receptors, and contains docking positions for proteins that transduce signaling through multiple pathways. We identified the adaptor protein ventricular zone-expressed pleckstrin homology domain-containing protein 1 (VEPH1) as a potential interacting partner of ERBB2 in a screen of proteins co-immunoprecipitated with VEPH1. In this study, we confirm a VEPH1 - ERBB2 interaction by co-immunoprecipitation and biotin proximity labelling and show that VEPH1 interacts with the juxtamembrane-kinase domain of ERBB2. In SKOV3 ovarian cancer cells, which bear a PIK3CA mutation and ERBB2 overexpression, ectopic VEPH1 expression enhanced EGF activation of ERK1/2, and mTORC2 activation of AKT. In contrast, in ES2 ovarian cancer cells, which bear a BRAF^V600E mutation with VEPH1 amplification but low ERBB2 expression, loss of VEPH1 expression enabled further activation of ERK1/2 by EGF and enhanced EGF activation of AKT. VEPH1 expression in SKOV3 cells enhanced EGF-induced cell migration consistent with increased Snail2 and decreased E-cadherin levels. In comparison, loss of VEPH1 expression in ES2 cells led to decreased cell motility independent of EGF treatment despite higher levels of N-cadherin and Snail2. Importantly, we found that loss of VEPH1 expression rendered ES2 cells less sensitive to BRAF and MEK inhibition. This study extends the range of adaptor function of VEPH1 to ERBB2, and indicates VEPH1 has differential effects on EGF signaling in ovarian cancer cells that may be influenced by driver gene mutations.

Expanding the Spectrum of BRAF Non-V600E Mutations in Thyroid Nodules: Evidence-Based Data from a Tertiary Referral Centre

The BRAF p.V600E mutation represents the most specific marker for papillary thyroid carcinoma and is potentially related to aggressive behavior and persistent disease. BRAF alterations other than the p.V600E are less common in thyroid carcinoma and represent an alternative mechanism of BRAF activation with unclear clinical significance. The study aims to describe the frequency and clinicopathologic characteristics of BRAF non-V600E mutations in a large cohort (1654 samples) of thyroid lesions characterized by next-generation sequencing. BRAF mutations have been found in 20.3% (337/1654) of thyroid nodules, including classic (p.V600E) mutation in 19.2% (317/1654) of samples and non-V600E variants in 1.1% of cases (19/1654). BRAF non-V600E alterations include 5 cases harboring p.K601E, 2 harboring p.V600K substitutions, 2 with a p.K601G variant, and 10 cases with other BRAF non-V600E alterations. BRAF non-V600E mutations have been reported in one case of follicular adenoma, three cases of conventional papillary thyroid carcinoma, eight cases of follicular variant of papillary carcinomas, one case of columnar cell variant papillary thyroid carcinoma, one case of oncocytic follicular carcinoma, and two bone metastasis of follicular thyroid carcinoma. We confirm that BRAF non-V600E mutations are uncommon and typically found in indolent follicular-patterned tumors. Indeed, we show that BRAF non-V600E mutations can be found in tumors with metastatic potential. However, in both aggressive cases, the BRAF mutations were concomitant with other molecular alterations, such as TERT promoter mutation.

The implication of BRAF mutation in advanced colorectal cancer

BACKGROUND

Advanced colorectal cancer (CRC) is frequently a lethal disease. Mutations in the BRAF gene is a key driver in CRC pathogenesis and confers a poor prognosis. To date, Irish data on this molecular subtype of CRC is lacking.

AIMS

Our aim was to compare the natural history of Irish patients with BRAF (BRAFMUT) metastatic CRC with a control group of metastatic CRC patients without BRAF mutation (BRAFWT wild- type).

METHOD

A retrospective observational analysis of advanced CRC patients with known BRAFMUT was conducted by chart review. BRAFMUT patients were identified from the Cork University Hospital (CUH) histopathology database. Controls with known BRAFWT were randomly selected from the database. Demographic characteristics and clinicopathological data were recorded. Survival was assessed with Kaplan-Meier curve/Cox proportional hazard models.

RESULTS

Twenty patients with BRAFMUT and 36 with BRAFWT were studied. BRAFMUT were more likely female (75% vs 33%, p = 0.007) and right-sided (65% vs 31.4%, p = 0.033). Median overall survival was lower in BRAFMUT group (17.3 months (95% CI 0-40.8)) compared to patients with BRAFWT (median survival not reached, log rank p = 0.001). On multivariate analysis, BRAFMUT was independently associated with an increased risk of mortality (HR 12.76 (95% CI 3.15-51.7), p < 0.001).

CONCLUSION

BRAFMUT advanced colorectal cancer was associated with significantly reduced overall survival in this Irish CRC population. Knowledge of mutation status should now be considered standard of care and should dictate management. Surgeons should be aware of this genetic signature as the natural history of the disease may mitigate against an aggressive surgical strategy. A prospective study should be conducted to further corroborate these findings.

Ophthalmic adverse effects of BRAF inhibitors

To determine the frequency, characteristics, and clinical course of ophthalmic side effects associated with systemic BRAF inhibitor therapy. Medical records of patients taking BRAF inhibitors for the treatment of systemic malignances at Mayo Clinic, Rochester from 01/01/2010 to 08/30/2021, were retrospectively reviewed. Of 901 patients, 14 (1.6%) patients experienced an ophthalmic side effect. Mean age at presentation of the side effect was 60 years (median 59, range 50-80) and 11 (79%) were male. The most common side effect was uveitis in 7 (50%) patients, followed by dry eye in 4 (29%) patients, and central serous chorioretinopathy in 2 (14%) patients, with singular cases of cranial nerve VI palsy and conjunctival edema. A comparison between individual BRAF inhibitors (vemurafenib vs. dabrafenib vs. encorafenib) revealed that patients taking encorafenib had a shorter interval to any ophthalmic adverse event (mean 55.6 vs. 9.8 vs. 4.0 months, p  =  0.03) and were the only patients to experience documented dry eye syndrome (DES) in this series. Outcomes were known in 13 (93%) patients, and ophthalmic adverse effects resolved or were controlled without discontinuing therapy in 10 (77%). Uveitis was successfully treated with topical corticosteroids in 4 patients, while 3 patients with refractory uveitis (2 with panuveitis and 1 with unspecified uveitis) required discontinuation of BRAF inhibitor therapy. Ophthalmic adverse events related to systemic BRAF inhibitor use are rare, with estimated frequency of 1.6%. Most events can be treated with local ophthalmic therapy. BRAF inhibitors provide life-saving therapy, and their discontinuation should be avoided.

Rapid response to monotherapy with MEK inhibitor trametinib for a lung adenocarcinoma patient harboring primary SDN1-BRAF fusion: A case report and literature review

BRAF gene has been identified as an oncogenic driver and a potential target in various malignancies. BRAF fusions are one subtype of BRAF alterations with a rare frequency. Here, we first report a previously treated advanced lung adenocarcinoma patient with de novo SND1-BRAF fusion who achieves partial response to the MAK inhibitor trametinib. We also provide a literature review on targeted therapies for BRAF fusions.

Targeted therapies in the medical management of craniopharyngioma

Craniopharyngioma (CP) is an intracranial benign tumor that behaves aggressively due to its location, infiltration of the surrounding nervous tissue and high capacity for recurrence. Treatment of choice is surgery followed or not by radiotherapy. Recent advances in molecular biology techniques and the better understanding of the genetic alterations of the two histological types of CP have open new therapeutic perspectives with targeted drugs. Adamantinomatous CP (ACP) is associated with activating mutations of the CTNNB1 gene. Such mutations are accompanied by intracellular accumulation of β-catenin, an oncogenic protein that activates the intracellular Wnt/ β-catenin signaling pathway, which regulates the transcription of genes involved in cell proliferation. Therefore, the use of molecular therapies directed against the activation of the Wnt/ β-catenin pathway could be an attractive and promising therapeutic option in the management of ACPs. On the other hand, papillary CP (PCP) is associated with activating mutations in the BRAF gene. This gene encodes a BRAF protein that plays an important role in the intracellular mitogen-activated protein kinase (MAPK) signaling pathway, which also regulates cell proliferation. The use of BRAF inhibitors either in monotherapy or in combination with mitogen-activated protein kinase (MEK) inhibitors has demonstrated therapeutic efficacy in isolated clinical cases of relapsed PCPs. A preliminary report of a recent phase II clinical trial has shown a therapeutic response in 93.7% of patients with BRAF ^V600E -mutated PCP, with an 85% reduction in tumor size. In the present review we comment on the efficacy and safety of the different drugs being used in patients with PCP.

Non-canonical genomic driver mutations of urethane carcinogenesis

The carcinogen urethane induces pulmonary tumors in mice initiated by an incredibly specific Q61L/R oncogenic mutation in the proto-oncogene Kras. Previous Whole-Exome Sequencing of urethane-induced tumors revealed a bias towards A➙T/G and G➙A substitutions. Subsequent ultra-sensitive Maximum-Depth Sequencing of Kras shortly after urethane exposure suggest a further refinement to CA➙CT/G substitutions. As C182AA➙C182T/GA substitutions in Kras result in Q61L/R mutations, the extreme bias of urethane towards these genomic driver mutations can be ascribed to the specificity of the carcinogen for CA➙CT/G substitutions. However, we previously found that changing rare codons to common in the Kras gene to increase protein expression shifted mutations in urethane-induced tumors away from Kras, or when detected in Kras, to G12D mutations that are usually rarely detected in such tumors. Moreover, the loss of p53 partially reversed this effect, generating tumors with either Q61L/R or G12D oncogenic Kras mutations, or no Kras mutations, presumably due to other genomic driver mutations. Determining the origin of these G12D and other unknown non-canonical genomic driver mutations would provide critical insight into the extreme bias of carcinogens for specific genomic driver mutations. We thus compared the types of Single Nucleotide Variations detected by previously performed Maximum-Depth Sequencing immediately after urethane exposure to the mutation signatures derived from Whole Exome Sequencing of urethane-induced tumors. This identified two types of non-canonical mutations. First, a V637E oncogenic mutation in the proto-oncogene Braf that conforms to the mutation signature of urethane, suggesting that the mutational bias of the carcinogen may account for this non-canonical mutation, similar to that for canonical Q61L/R mutations in Kras. Second, G12D and Q61H mutations in Kras that did not fit this mutation signature, and instead shared similarity with Single Nucleotide Variations detected by Maximum-Depth Sequencing from normal cells, suggesting that perhaps these mutations were pre-existing. We thus posit that when canonical Kras mutations are selected against that the carcinogen may instead promote the expansion of pre-existing genomic driver mutations, although admittedly we cannot rule out other mechanisms. Interrogating the mutation signatures of human lung cancers similarly identified KRAS genomic driver mutations that failed to match the mutation signature of the tumor. Thus, we also speculate that the selection for non-canonical genomic driver mutations during urethane carcinogenesis may reflect the process by which discordance between genomic driver mutations and mutational signatures arises in human cancers.

Clinical, Radiological, Pathological Features and Seizure Outcome With Surgical Management of Polymorphous Low-Grade Neuroepithelial Tumor of the Young Associated With Epilepsy

Objective

Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a novel distinct epileptogenic neoplasm, and its clinical, imaging, histopathological, and molecular features were already known in the existing literature. We aimed to analyze the surgical management of PLNTY combined with these known characteristics.

Methods

Eight patients underwent surgical treatment in our center between December 2017 and December 2020, and the postoperative pathology was diagnosed as PLNTY. Their clinical data, imaging, pathological, molecular characteristics, and seizure outcome were retrospectively analyzed. Follow-up evaluations and a literature review were performed.

Results

The 8 patients included 1 woman and 7 men, aged between 5 and 51 years old (mean = 31.6, median = 29). The preoperative symptoms of all 8 cases were seizures. Four tumors were situated in the temporal lobes, and one of the four extratemporal tumors was in the occipital lobe and three were in the frontal lobe. Enlarged and gross total resections were performed in 2 cases and the other 6 cases, respectively. All cases exhibited intense labeling of CD34, and absence of 1p/19q codeletion and IDH1 or IDH2 mutation. B-Raf proto-oncogene (BRAF) V600E mutation was presented in 4 (66.7%) of 6 detected cases. The postoperative seizure outcome of Engel class I was achieved in 6 cases (75%).

Conclusion

PLNTY represents distinctive histologic, immunophenotypic and biomolecular features, and has high epileptogenicity. Early surgical intervention and enlarged resection of PLNTY associated with epilepsy will help to improve the postoperative seizure-free rate.

Clinicopathological and Molecular Features of Secondary Cancer (Metastasis) to the Thyroid and Advances in Management

Secondary tumours to the thyroid gland are uncommon and often incidentally discovered on imaging. Symptomatic patients often present with a neck mass. Collision tumours of secondary tumours and primary thyroid neoplasms do occur. Ultrasound-guided fine-needle aspiration, core-needle biopsy, and surgical resection with histological and immunohistochemical analysis are employed to confirm diagnosis as well as for applying molecular studies to identify candidates for targeted therapy. Biopsy at the metastatic site can identify mutations (such as EGFR, K-Ras, VHL) and translocations (such as EML4-ALK fusion) important in planning target therapies. Patients with advanced-stage primary cancers, widespread dissemination, or unknown primary origin often have a poor prognosis. Those with isolated metastasis to the thyroid have better survival outcomes and are more likely to undergo thyroid resection. Systemic therapies, such as chemotherapy and hormonal therapy, are often used as adjuvant treatment post-operatively or in patients with disseminated disease. New targeted therapies, such as tyrosine kinase inhibitors and immune checkpoint inhibitors, have shown success in reported cases. A tailored treatment plan based on primary tumour features, overall cancer burden, and co-morbidities is imperative. To conclude, secondary cancer to the thyroid is uncommon, and awareness of the updates on diagnosis and management is needed.

Pancreatic Neuroendocrine Neoplasms: Updates on Genomic Changes in Inherited Tumour Syndromes and Sporadic Tumours Based on WHO Classification

Pancreatic neuroendocrine neoplasms (PanNENs) are the neuroendocrine neoplasms with greatest rate of increase in incidence. Approximately 10% of PanNENs arise as inherited tumour syndromes which include multiple endocrine neoplasia type 1, multiple endocrine neoplasia type 4, von Hippel-Lindau syndrome, neurofibromatosis type1, tuberous sclerosis complex 1/2, Cowden syndrome, and Glucagon cell hyperplasia and neoplasia as well as familial insulinomatosis. In sporadic PanNENs, driver mutations in MEN1, DAXX/ATRX and mTOR pathway genes are associated with development and progression in pancreatic neuroendocrine tumours. The other changes are in VEGF pathway, Notch pathway, germline mutations in MUTYH, CHEK2, BRCA2, PHLDA3 as well as other genetic alterations. On the other hand, pancreatic neuroendocrine carcinomas share similar genetic alterations with ductal adenocarcinomas, e.g., TP53, RB1 or KRAS. In addition, microRNA and changes in immune microenvironment were noted in PanNENs. Updates on these genetic knowledges contribute to the development of management strategies for patients with PanNENs.

Risk of extracolonic second primary cancers following a primary colorectal cancer: a systematic review and meta-analysis

PURPOSE

The purpose of the study is to assess the global risk of extracolonic secondary primary cancers (SPCs) in patients with colorectal cancer (CRC).

METHODS

Studies of SPC in patients with CRC were included if they reported the standardised incidence ratio (SIR) for extracolonic SPCs in patients with CRC compared with the general population. Pooled summary estimates were calculated using a random-effects model.

RESULTS

A total of 7,716,750 patients with CRC from 13 retrospective cohort studies that reported extracolonic SPC incidence were included. The overall risk of several SPCs was significantly higher in patients with CRC compared with the general population, including cancers of the urinary bladder (pooled SIR 1.19, 95% confidence interval (CI) 1.06-1.33; p = 0.003), female genital tract (1.88, 1.07-3.31; p = 0.03), kidney (1.50, 1.19-1.89; p = 0.0007), thorax (lung, bronchus and mediastinum) (1.16, 1.01-1.32; p = 0.03), small intestine (4.26, 2.58-7.01; p < 0.0001), stomach (1.22, 1.07-1.39; p = 0.003), and thyroid (1.40, 1.28-1.53; p < 0.0001), as well as melanoma (1.28, 1.01-1.62; p = 0.04). There was also a decreased risk of developing cancer of the gall bladder (0.75, 0.60-0.94; p = 0.01).

CONCLUSION

Patients with CRC had a significantly increased risk of extracolonic SPCs compared with the general population. These findings highlight the need to develop research strategies for the management of second primary cancer in patients with CRC.

Prophylactic vaccines against cancers of non-infectious origin: a dream or a real possibility?

The dramatic progress in tumour biology and immunology in the past several years has opened new avenues for the treatment and prevention of cancer. One of the great contributions of the immunotherapeutic approaches is an increasing understanding of the immunology of cancer, which is, gradually creating conditions for the development of prophylactic anti-cancer vaccines. Efficient vaccines have been developed and employed for the prophylaxis of two frequent cancers of viral origin, namely cervical cancer and liver cancer. The new knowledge on the interactions between the immune system and the malignant tumors seems to provide means for the development of prophylactic vaccines against cancers developing due to the mutations in the proto-oncogenes converting their products into oncoproteins. According to the present estimates, these cancers form a great majority of human malignancies. Recent evidence has indicated that the immune system recognizes such mutated proteins, and that the development of cancer is due to the failure of the immune system to eliminate neoplastic cells. Followingly, it can be expected that inducing immunity against the mutated epitopes will increase the capacity of the body to deal with the initiated precancerous cells. In the present paper this hypothesis is primarily discussed in the relationship with colorectal cancer (CRC), which seems to be a well-fitting candidate for prophylactic vaccination. CRC is the third most frequent malignancy and the fourth most common cause of cancer mortality. Mutations of two proto-oncogenes, namely RAS and RAF, are involved in the majority of CRC cases and, in addition, they are shared with other human malignancies. Therefore, the strategy to be used for prophylaxis of CRC is discussed together with several other frequent human cancers, namely lung cancer, pancreatic duct cancer and melanoma. The prophylactic vaccines proposed are aimed at the reduction of the incidence of these and, to a lesser extent, some other cancers.

Variations in MAP kinase gladiators and risk of differentiated thyroid carcinoma

Thyroid carcinoma (TC) accounts for ~2.1% of newly diagnosed cancer cases. Mutations in KRAS, HRAS, NRAS and BRAF are primary participants in the development and progression of various types of malignancy, including differentiated TC (DTC). Therefore, the present prospective cohort study aimed to screen patients with DTC for variations in RAS gene family and BRAF gene. Exon 1 and 2 of KRAS, HRAS, NRAS and exon 15 of BRAF gene were screened for hotspot mutations in 72 thyroid tumor and adjacent normal tissue samples using di-deoxy Sanger sequencing. HRAS T81C mutation was found in 21% (15 of 72) of DTC tissue samples, therefore this mutation was investigated in blood samples from patients with DTC and controls as a genetic polymorphism. In addition, HRAS T81C genotypes were determined in 180 patients with DTC and 220 healthy controls by performing restriction fragment length polymorphism. BRAF^V600E mutation was confined to classical variant of papillary thyoid cancer (CPTC; 44.4%) and was significantly associated with multifocality and lymph node (LN) metastasis. No mutation was found in exons 1 and 2 of KRAS and NRAS and exon 2 of HRAS genes, however, mutation was detected in exon 1 of HRAS gene (codon 27) at nucleotide position 81 in 21% (15 of 72) of DTC tumor tissue samples. Furthermore, HRAS T81C single nucleotide polymorphism was significantly associated with the risk of DTC with variant genotypes more frequently detected in cases compared with controls (P≤0.05). Moreover, frequency of variant genotypes (TC+CC) was significantly higher among DTC cases with no history of smoking, males, greater age, multifocality and LN metatasis compared with healthy controls (P<0.05). BRAF^V600E mutation was primarily present in CPTC and associated with an aggressive tumor phenotype but mutations in RAS gene family were not present in patients with DTC. HRAS T81C polymorphism may be involved in the etiopathogenesis of DTC in a Pakistani cohort. Furthermore, testing for the BRAF^V600E mutation may be useful for selecting initial therapy and follow-up monitoring.

Histopathological Assessment for Papillary Thyroid Carcinoma

Histologic assessments of papillary thyroid carcinoma are crucial for management of patients with the cancer as well as research on the cancer as papillary thyroid carcinoma has different histologic subtypes and many parameters which are essential in predicting the biological aggressiveness of the cancer. The histologic assessments should be guided by universally adopted protocols including World Health Organization (WHO) classification of endocrine tumors, International Collaboration on Cancer Reporting (ICCR) dataset, American Thyroid Association initial risk stratification for differentiated thyroid carcinomas and TNM stage groupings. The essential steps in histologic assessment involve the identification of characteristic features of papillary thyroid carcinoma, correct histologic subtyping, noting the number of carcinomas, measuring the size of the carcinoma, documenting the different aggressive histological parameters (mitotic activity, presence of tumor encapsulation/circumscription, lymphatic vessel invasion, blood vessel invasion, necrosis, extrathyroidal extension), resection margin status, associated pathology, presence of parathyroid gland, lymph node and distant metastases as well as synthesis of pathological stage based on the various clinical, macroscopic, and histological features.

BRAF Mutations in Papillary Thyroid Carcinoma: A Genomic Approach Using Probe-Based DNA Capture for Next-Generation Sequencing

The BRAF V600E mutation in papillary thyroid carcinoma is the major mutation in classical subtype of papillary thyroid carcinoma and other cancers. It is the most studied predictor of clinical and pathological characteristics as well as molecular targets for cancer therapy. On the other hand, there is potential for many more forms of activating mutation in BRAF that are not detectable by simple assays to detect V600E, or even simple polymerase chain reaction (PCR)-based sequencing for full-length BRAF. Such activating mutations could arise from larger-scale rearrangements which may apparently leave no sequence change to BRAF while causing increased expression or activation by unusual means, such as gene fusion. Detection of these kinds of changes can take place using a variety of methods, though capture-based sequencing can identify the existence of such forms of mutant BRAF without needing foreknowledge of the loci involved in these kinds of mutation. In this chapter, we detail a method for capture of specific DNA sequences and their amplification to prepare for massively parallel sequencing.

The Combined Utility of HBME-1 and Galectin-3 Immunohistochemistry and BRAF V600E Mutations in the Diagnosis of Papillary Thyroid Carcinoma

Newer diagnostic modalities have revolutionized the pathologist’s approach to diagnosing thyroid malignancies. Molecular characterization of these malignancies has helped circumvent common morphologic diagnostic difficulties by integrating their genotypic, phenotypic, and immunohistochemical features. BRAF V600E mutation has been characterized as highly specific for thyroid carcinoma, especially papillary thyroid carcinoma (PTC); human bone marrow endothelial marker-1 (HBME-1) and galectin-3 are also such markers that are highly specific for PTC. We propose to study HBME-1 and galectin-3 expression and BRAF V600E mutation in thyroid neoplasms and do a comparative analysis to determine whether there is a correlation between BRAF V600E expression and that of HBME-1 and galectin-3. We further propose to analyze the individual and combined diagnosed utility of the above-mentioned ancillary diagnostic techniques.

Resistance to anti-EGFR therapies in metastatic colorectal cancer: underlying mechanisms and reversal strategies

Cetuximab and panitumumab are monoclonal antibodies (mAbs) against epidermal growth factor receptor (EGFR) that are effective agents for metastatic colorectal cancer (mCRC). Cetuximab can prolong survival by 8.2 months in RAS wild-type (WT) mCRC patients. Unfortunately, resistance to targeted therapy impairs clinical use and efficiency. The mechanisms of resistance refer to intrinsic and extrinsic alterations of tumours. Multiple therapeutic strategies have been investigated extensively to overcome resistance to anti-EGFR mAbs. The intrinsic mechanisms include EGFR ligand overexpression, EGFR alteration, RAS/RAF/PI3K gene mutations, ERBB2/MET/IGF-1R activation, metabolic remodelling, microsatellite instability and autophagy. For intrinsic mechanisms, therapies mainly cover the following: new EGFR-targeted inhibitors, a combination of multitargeted inhibitors, and metabolic regulators. In addition, new cytotoxic drugs and small molecule compounds increase the efficiency of cetuximab. Extrinsic alterations mainly disrupt the tumour microenvironment, specifically immune cells, cancer-associated fibroblasts (CAFs) and angiogenesis. The directions include the modification or activation of immune cells and suppression of CAFs and anti-VEGFR agents. In this review, we focus on the mechanisms of resistance to anti-EGFR monoclonal antibodies (anti-EGFR mAbs) and discuss diverse approaches to reverse resistance to this therapy in hopes of identifying more mCRC treatment possibilities.

BRAF mutations may identify a clinically distinct subset of glioblastoma

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Prior studies examining the mutational landscape of GBM revealed recurrent alterations in genes that regulate the same growth control pathways. To this regard, ~ 40% of GBM harbor EGFR alterations, whereas BRAF variants are rare. Existing data suggests that gain-of-function mutations in these genes are mutually exclusive. This study was designed to explore the clinical, pathological, and molecular differences between EGFR- and BRAF-mutated GBM. We reviewed retrospective clinical data from 89 GBM patients referred for molecular testing between November 2012 and December 2015. Differences in tumor mutational profile, location, histology, and survival outcomes were compared in patients with EGFR- versus BRAF-mutated tumors, and microarray data from The Cancer Genome Atlas was used to assess differential gene expression between the groups. Individuals with BRAF-mutant tumors were typically younger and survived longer relative to those with EGFR-mutant tumors, even in the absence of targeted treatments. BRAF-mutant tumors lacked distinct histomorphology but exhibited unique localization in the brain, typically arising adjacent to the lateral ventricles. Compared to EGFR- and IDH1-mutant tumors, BRAF-mutant tumors showed increased expression of genes related to a trophoblast-like phenotype, specifically HLA-G and pregnancy specific glycoproteins, that have been implicated in invasion and immune evasion. Taken together, these observations suggest a distinct clinical presentation, brain location, and gene expression profile for BRAF-mutant tumors. Pending further study, this may prove useful in the stratification and management of GBM.

Cutaneous adverse events in children treated with vemurafenib for refractory BRAFV600E mutated Langerhans cell histiocytosis

BACKGROUND

The somatic BRAF^V600E mutation occurs in 38-64% of pediatric cases of Langerhans cell histiocytosis (LCH). Vemurafenib (VMF), a BRAF inhibitor, was approved for refractory BRAF^V600E mutated LCH. In adults, VMF causes frequent cutaneous adverse events (CAE) including skin tumors (squamous cell carcinomas, melanomas), but little is known in children. The objective of this study was to evaluate the frequency, clinical spectrum, and severity of CAEs in children treated with VMF for LCH. In addition, a correlation between CAE occurrence and VMF dose, residual plasma levels (RPLs), and efficacy was searched for.

PROCEDURE

Multicentric retrospective observational study including patients <18 years treated with VMF alone for refractory BRAF^V600E mutated LCH in 13 countries between October 1, 2013 and December 31, 2018.

RESULTS

Fifty-seven patients: 56% female, median age 2.1 years (0.2-14.6), median treatment duration 4.1 months (1.4-29.7). Forty-one patients (72%) had at least one CAE: photosensitivity (40%), keratosis pilaris (32%), rash (26%), xerosis (21%), and neutrophilic panniculitis (16%). No skin tumor was observed. Five percent of CAEs were grade 3. None were grade 4 or led to permanent VMF discontinuation. Dose reduction was necessary for 12% of patients, temporary treatment discontinuation for 16%, none leading to loss of efficacy. VMF dose, median RPL, and efficacy were not correlated with CAE occurrence.

CONCLUSIONS

At doses used for pediatric LCH, CAEs are frequent but rarely severe and have little impact on the continuation of treatment when managed appropriately. Regular dermatological follow-up is essential to manage CAEs and screen for possible induced skin tumors.

The Association Between Radioiodine Refractory in Papillary Thyroid Carcinoma, Sodium/Iodide Symporter Expression, and BRAF V600E Mutation

Objective

To study the association between radioiodine refractory papillary thyroid carcinoma, sodium/iodide symporter (NIS) expression, and the BRAF ^V600E mutation.

Methods

A study was conducted on 30 radioiodine refractory papillary thyroid carcinoma patients and 30 radioiodine-avid papillary thyroid carcinoma patients. The expressions of sodium/iodide symporter and BRAF ^V600E mutated protein were determined by immunohistochemistry using formalin-fixed, paraffin-embedded tissue.

Results

The mutated BRAF ^V600E protein was identified in 26 radioiodine refractory papillary thyroid carcinoma subjects (86.7%) and 22 radioiodine-avid papillary thyroid carcinoma subjects (73.3%), with no significant difference between the 2 groups (P = 0.3). Sodium/iodide symporter expression was detected in 4 of 30 cases (13.3%) from the radioiodine-avid papillary thyroid carcinoma group but was negative for all radioiodine refractory cases. There was no association between sodium/iodide symporter expression and radioiodine refractory papillary thyroid carcinoma (P = 0.11). Cases with positive NIS expression were likely negative for BRAF ^V600E mutation (3/4; P = 0.02).

Conclusion

Papillary thyroid carcinomas with BRAF ^V600E mutation were more likely to be negative for NIS expression. BRAF ^V600E mutation and NIS expressions cannot be used to predict radioiodine sensitivity.

The Role of Snail-1 in Thyroid Cancer-What We Know So Far

Thyroid carcinomas, despite the usually indolent behaviour and relatively good overall prognosis, show a high tendency to gain invasive phenotype and metastasise in some cases. However, due to a relatively slow progression, the exact mechanisms governing the metastatic process of thyroid carcinomas, including the epithelial-to-mesenchymal transition (EMT), are poorly described. One of the best-known regulators of cancer invasiveness is Snail-1-a zinc-finger transcription factor that plays a key role as an EMT inducer. More and more attention is being paid to the role of Snail with regard to thyroid cancer development. Apart from the obvious implications in the EMT process, Snail-1 plays an important role in the regulation of chemoresistance of the thyroid cells and cancer stem cell (CSC) formation, and it also interacts with miRNA specific to the thyroid gland. The aim of this review was to summarise the knowledge on Snail-1, especially in the context of thyroid oncogenesis.

Immunohistochemical Validation of Rare Tissues and Antigens With Low Frequency of Occurrence: Recommendations From The Anatomic Pathology Patient Interest Association (APPIA)

Laboratories worldwide find it challenging to identify enough tissues and cases for verification and validation studies of low-incidence, rare antigens. These antigens have a low frequency of occurrence in the population, or have little or no expression in normal tissues. Validation studies are essential to assure testing standardization before introducing a new instrument, product, or test into the clinical laboratory. The College of American Pathologists has published comprehensive guidelines for the verification and validation of new immunohistochemical tests introduced into the laboratory menu. Within the guidelines, varied numbers of cases are required for nonpredictive versus predictive markers. However, regarding low-incidence antigens, the laboratory medical director determines the extent of validation required. Recommended practical solutions available to clinical laboratories for low-incidence validation include developing internal resources using the laboratory information system with retrospective and prospective search(s) of archival material and purchase of tissue microarray blocks, slides, or cell lines from external resources. Utilization of homemade multitissue blocks has proved to be extremely valuable in biomarker research and demonstrated great utility in clinical immunohistochemistry laboratories. Participation in External Quality Assessment program(s) may provide insufficient numbers or the ability to calculate concordance rates. However, supplementation with in-house tissues can allow a laboratory to reach the optimal number of cases needed for verification and/or validation schemes. An alternative approach is conducting a thorough literature search and correlating staining patterns of the new test to the expected results. These solutions may be used uniquely or together to assure consistent standardized testing.

BRAF V600E/V600K Mutations versus Nonstandard Alterations: Prognostic Implications and Therapeutic Outcomes

BRAF and MEK inhibitors are standard of care for BRAF V600E/K-mutated melanoma, but the benefit of BRAF and/or MEK inhibitors for nonstandard BRAF alterations for melanoma and other cancers is unclear. Patients with diverse malignancies whose cancers had undergone next-generation sequencing were screened for BRAF alterations. Demographics, treatment with BRAF and/or MEK inhibitors, clinical response, progression-free survival (PFS), and overall survival (OS) were determined from review of the electronic medical records for patients with standard BRAF V600E/K versus nonstandard BRAF alterations. A total of 213 patients with BRAF alterations (87 with nonstandard alterations) were identified; OS from diagnosis was significantly worse with nonstandard BRAF versus standard alterations, regardless of therapy [HR (95% confidence interval), 0.58 (0.38-0.88); P = 0.01]. Overall, 45 patients received BRAF/MEK-directed therapy (eight with nonstandard alterations); there were no significant differences in clinical benefit rate [stable disease ≥6 months/partial/complete response (74% vs. 63%; P = 0.39) or PFS (P = 0.24; BRAF V600E/K vs. others)]. In conclusion, patients with nonstandard versus standard BRAF alterations (BRAF V600E/K) have a worse prognosis with shorter survival from diagnosis. Even so, 63% of patients with nonstandard BRAF alterations achieved clinical benefit with BRAF/MEK inhibitors. Larger prospective studies are warranted to better understand the prognostic versus predictive implication of standard versus nonstandard BRAF alterations.

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

Background

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

Methods

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

Results

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

Conclusion

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

Anaplastic Thyroid Carcinoma: Current Issues in Genomics and Therapeutics

PURPOSE OF REVIEW

Anaplastic thyroid carcinoma is a type of thyroid carcinoma with the most aggressive biological behaviour amongst thyroid cancer. Here, we review the current genomic and the impacts of advances in therapies to improve the management of patients with the cancer.

RECENT FINDINGS

Common mutations being identified in anaplastic thyroid carcinoma are p53 and TERT promoter mutations. Other common mutated genes included BRAF, RAS, EIF1AX, PIK3CA, PTEN and AKT1, SWI/SNF, ALK and CDKN2A. Changes in expression of different microRNAs are also involved in the pathogenesis of anaplastic thyroid carcinoma. Curative resection combined with radiotherapy and combination chemotherapies (such as anthracyclines, platins and taxanes) has been shown to have effects in the treatment of some patients with anaplastic thyroid carcinoma. Newer molecular targeted therapies in clinical trials target mostly the cell membrane kinase and downstream proteins. These include targeting the EGFR, FGFR, VEGFR, c-kit, PDGFR and RET on the cell membrane as well as VEGF itself and the downstream targets such as BRAF, MEK and mTOR. Immunotherapy is also being tested in the cancer. Updated knowledge of genomic as well as clinical trials on novel therapies is needed to improve the management of the patients with this aggressive cancer.

Nanocarrier-Based Drug Delivery for Melanoma Therapeutics

Melanoma, as a tumor cell derived from melanocyte transformation, has the characteristics of malignant proliferation, high metastasis, rapid recurrence, and a low survival rate. Traditional therapy has many shortcomings, including drug side effects and poor patient compliance, and so on. Therefore, the development of an effective treatment is necessary. Currently, nanotechnologies are a promising oncology treatment strategy because of their ability to effectively deliver drugs and other bioactive molecules to targeted tissues with low toxicity, thereby improving the clinical efficacy of cancer therapy. In this review, the application of nanotechnology in the treatment of melanoma is reviewed and discussed. First, the pathogenesis and molecular targets of melanoma are elucidated, and the current clinical treatment strategies and deficiencies of melanoma are then introduced. Following this, we discuss the main features of developing efficient nanosystems and introduce the latest reports in the literature on nanoparticles for the treatment of melanoma. Subsequently, we review and discuss the application of nanoparticles in chemotherapeutic agents, immunotherapy, mRNA vaccines, and photothermal therapy, as well as the potential of nanotechnology in the early diagnosis of melanoma.

Targeting the Ras pathway in pediatric hematologic malignancies

PURPOSE OF REVIEW

Ras pathway mutations are one of the most common type of alterations in pediatric hematologic malignancies and are frequently associated with adverse outcomes. Despite ongoing efforts to use targeted treatments, there remain no Food and Drug Administration (FDA)-approved medications specifically for children with Ras pathway-mutated leukemia. This review will summarize the role of Ras pathway mutations in pediatric leukemia, discuss the current state of Ras pathway inhibitors and highlight the most promising agents currently being evaluated in clinical trials.

RECENT FINDINGS

Efficacy using RAF and MEK inhibitors has been demonstrated across multiple solid and brain tumors, and these are now considered standard-of-care for certain tumor types in adults and children. Clinical trials are now testing these medications for the first time in pediatric hematologic disorders, such as acute lymphoblastic leukemia, juvenile myelomonocytic leukemia, and histiocytic disorders. Novel inhibitors of the Ras pathway, including direct RAS inhibitors, are also being tested in clinical trials across a spectrum of pediatric and adult malignancies.

SUMMARY

Activation of the Ras pathway is a common finding in pediatric hematologic neoplasms. Implementation of precision medicine with a goal of improving outcomes for these patients will require testing of Ras pathway inhibitors in combination with other drugs in the context of current and future clinical trials.

Melanoma: clinical-pathological and molecular analysis in patients of Ibague city, Colombia

This study aimed to establish the clinicopathological characteristics of patients with melanoma and its association with BRAF gene mutations. The pathology reports and paraffin-embedded tumor samples from 47 women and 30 men with melanoma, with an average age of diagnosis of 60 years, were reviewed at the Hospital Federico Lleras Acosta of Ibague, between 2010 and 2016. The presence of V600E mutation at the exon 15 of BRAF gene, was analyzed in these tumoral samples by Sanger sequencing and visual inspection of the electropherograms. We also studied the clinicopathological variables with X2, t-Student and the Kaplan Meier index. Most of the lesions were located in the lower limbs (46.6%). The most frequent subtype was Acral Lentiginous Melanoma (41.8%). Most lesions were of poor prognosis: Breslow depth greater than 4.1 mm (52.7%), ulceration (61.4%) and medium or high mitotic rate (> 30 %). The V600E mutation was identified in five patients with large, deep and ulcerated tumors, four of them had less than four years of survival. In conclusion, there was a higher frequency of melanoma in women, V600E BRAF mutation was present in patients with advanced disease (high Breslow index) and, the probability of five-year survival was less than 40%.

BRAF-Mutated Colorectal Cancer: Clinical and Molecular Insights

Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity in the world. It is a heterogeneous disease, which can be classified into different subtypes, characterized by specific molecular and morphological alterations. In this context, BRAF mutations are found in about 10% of CRC patients and define a particular subtype, characterized by a dismal prognosis, with a median survival of less than 12 months. Chemotherapy plus bevacizumab is the current standard therapy in first-line treatment of BRAF-mutated metastatic CRC (mCRC), with triplet (FOLFOXIRI) plus bevacizumab as a valid option in patients with a good performance status. BRAF inhibitors are not so effective as compared to melanoma, because of various resistance mechanisms. However, the recently published results of the BEACON trial will establish a new standard of care in this setting. This review provides insights into the molecular underpinnings underlying the resistance to standard treatment of BRAF-mutated CRCs, with a focus on their molecular heterogeneity and on the research perspectives both from a translational and a clinical point of view.

Pediatric Brain Tumor Genetics: What Radiologists Need to Know

Brain tumors are the most common solid tumors in the pediatric population. Pediatric neuro-oncology has changed tremendously during the past decade owing to ongoing genomic advances. The diagnosis, prognosis, and treatment of pediatric brain tumors are now highly reliant on the genetic profile and histopathologic features of the tumor rather than the histopathologic features alone, which previously were the reference standard. The clinical information expected to be gleaned from radiologic interpretations also has evolved. Imaging is now expected to not only lead to a relevant short differential diagnosis but in certain instances also aid in predicting the specific tumor and subtype and possibly the prognosis. These processes fall under the umbrella of radiogenomics. Therefore, to continue to actively participate in patient care and/or radiogenomic research, it is important that radiologists have a basic understanding of the molecular mechanisms of common pediatric central nervous system tumors. The genetic features of pediatric low-grade gliomas, high-grade gliomas, medulloblastomas, and ependymomas are reviewed; differences between pediatric and adult gliomas are highlighted; and the critical oncogenic pathways of each tumor group are described. The role of the mitogen-activated protein kinase pathway in pediatric low-grade gliomas and of histone mutations as epigenetic regulators in pediatric high-grade gliomas is emphasized. In addition, the oncogenic drivers responsible for medulloblastoma, the classification of ependymomas, and the associated imaging correlations and clinical implications are discussed. ^©RSNA, 2018.

RAF kinases are stabilized and required for dendritic cell differentiation and function

RAF kinases (ARAF, BRAF, and CRAF) are highly conserved enzymes that trigger the RAF-MEK1/2-ERK1/2 (MAPK) pathway upon activation of RAS. Despite enormous clinical interest, relatively little is known on the role of RAFs in mediating immune responses. Here, we investigated the role of RAF kinases and MEK1/2 in dendritic cells (DCs), the central regulators of T cell-mediated antitumor immune responses and the adaptive immune system. We demonstrate that RAF kinases are active and stabilized at their protein levels during DC differentiation. Inhibition of RAF kinases but not MEK1/2 impaired the activation of DCs in both mice and human. As expected, DCs treated with RAF inhibitors show defects in activating T cells. Further, RAF and MEK1/2 kinases are directly required for the activation and proliferation of CD4⁺ T cells. Our observations suggest that RAF and MEK1/2 have independent roles in regulating DC function that has important implications for administering RAF–MAPK inhibitors in the clinics.

Pilocytic astrocytomas: BRAFV600E and BRAF fusion expression patterns in pediatric and adult age groups

PURPOSE

Pilocytic astrocytomas (PCAs) are characterized by two dominant molecular alterations of the BRAF gene, i.e., BRAFV600E mutation and KIAA1549-BRAF fusions which show a differential pattern of frequency across different age-groups.

METHODS

Formalin-fixed paraffin-embedded tissues of 358 (pediatric 276 and adult 82) consecutive PCAs were evaluated for BRAFV600E mutation by Sanger sequencing and KIAA1549:BRAF fusion transcripts (KIAA1549:BRAF 16-9, KIAA1549:BRAF 15-9, and KIAA1549:BRAF 16-11) by reverse transcriptase polymerase chain reaction, which were correlated with different clinicopathological features.

RESULTS

BRAFV600E mutation was detected in 8.9% pediatric and 9.75% adult PCAs, whereas 41.1% and 25.7% of pediatric and adult cases showed KIAA1549-BRAF fusions respectively. BRAFV600E did not show any statistically significant correlation with any of the clinical parameters (age, location, and gender). KIAA1549:BRAF fusions showed a significant statistical association with the pediatric age group and cerebellar location. KIAA1549-BRAF 16-9 was the commonest variant and was predominantly associated with cerebellar location than non-cerebellar whereas fusion variant 15-9 negatively correlated with cerebellar locations.

CONCLUSIONS

The present study showed overall frequency of 53.5% and 37.3% BRAF alterations in pediatric and adult PCA cases respectively. BRAF fusion in PCA cases showed a different distribution pattern across age groups and locations; while no such differential pattern was observed for BRAFV600E.

Detection of cell-free circulating BRAFV 600E by droplet digital polymerase chain reaction in patients with and without melanoma under dermatological surveillance

BACKGROUND

The p.V600E mutation in the BRAF protein is the most frequent mutation in cutaneous melanoma and is a recurrent alteration found in common benign naevi. Analysis of the cell-free BRAF c.1799T>A, p.V600E mutation (cfBRAF^{V 600E} ) in plasma has emerged as a biomarker for monitoring prognosis and treatment response in patients with melanoma.

OBJECTIVES

To quantify cfBRAF^{V 600E} levels in plasma from patients with melanoma and from patients without melanoma undergoing regular follow-up of their melanocytic lesions, in order to assess the clinical significance of the test.

METHODS

We quantified cfBRAF^{V 600E} by droplet digital polymerase chain reaction in plasma from 146 patients without melanoma undergoing continuous dermatological screening, from 26 stage III and seven stage IV patients with BRAF-mutant melanoma, and from 32 patients with melanoma who were free of disease for 3 or more years.

RESULTS

Among disease-free patients and individuals without melanoma, 52% presented a high naevus count (> 50) and 49% had clinically atypical naevi. cfBRAF^{V 600E} was detected in 71% of patients with stage IV melanoma and 15% with stage III, and in 1·4% of individuals without melanoma. No cfBRAF^{V 600E} mutation was detected in disease-free patients with melanoma. Individuals without melanoma had lower cfBRAF^{V 600E} levels than patients with melanoma. We established a variant allelic frequency of 0·26% or 5 copies mL^-1 of cfBRAF^{V 600E} as the optimal cutoff value for identifying patients with melanoma with > 99% specificity.

CONCLUSIONS

This study suggests that naevus-related factors do not influence the detection of cfBRAF^{V 600E} in individuals without melanoma, and supports the clinical diagnostic value of plasma cfBRAF^{V 600E} quantification in patients with melanoma. What's already known about this topic? The analysis of the BRAF c.1799T>A (p.V600E) mutation in cell-free (cf)DNA has emerged as a potential biomarker for monitoring prognosis and treatment response in patients with metastatic BRAF^V600E melanoma. The BRAF^V600E alteration is a common genetic alteration found in benign proliferations such as melanocytic naevi. No information exists about the impact of the number of common acquired naevi or the presence of clinically atypical naevi in cfBRAF^V600E detection in an individual. What does this study add? The cfBRAF^V600E mutation is detected in plasma from a reduced number of individuals without melanoma undergoing continuous dermatological follow-up. A high number of naevi or the presence of clinically atypical naevi are factors that do not influence cfBRAF^V600E detection in an individual. Both total cfBRAF concentration and cfBRAF^V600E frequency are effective biomarkers in patients with advanced melanoma but not in patients at early stages or with micrometastases. What is the translational message? Detection of cfBRAF^V600E in an individual is not influenced by naevus-related factors. cfBRAF^V600E is a robust and reliable biomarker that can be used in dermatological surveillance programmes.