Complete response of metastatic microsatellite-stable BRAF V600E colorectal cancer to first-line oxaliplatin-based chemotherapy and immune checkpoint blockade.

The randomized METIMMOX trial (NCT03388190) examined if patients with previously untreated, unresectable abdominal metastases from microsatellite-stable (MSS) colorectal cancer (CRC) might benefit from potentially immunogenic, short-course oxaliplatin-based chemotherapy alternating with immune checkpoint blockade (ICB). Three of 38 patients assigned to this experimental treatment had metastases from BRAF-mutant MSS-CRC, in general a poor-prognostic subgroup explored here. The ≥70-year-old females presented with ascending colon adenocarcinomas with intermediate tumor mutational burden (6.2-11.8 mutations per megabase). All experienced early disappearance of the primary tumor followed by complete response of all overt metastatic disease, resulting in progression-free survival as long as 20-35 months. However, they encountered recurrence at previously unaffected sites and ultimately sanctuary organs, or as intrahepatic tumor evolution reflected in the terminal loss of initially induced T-cell clonality in liver metastases. Yet, the remarkable first-line responses to short-course oxaliplatin-based chemotherapy alternating with ICB may offer a novel therapeutic option to a particularly hard-to-treat MSS-CRC subgroup.

Spectrum and Frequency of BRAF Mutations in Skin Melanomas in the Dalmatian Region of Croatia.

Mutation of the BRAF oncogene is one of the most common mutations detected in human neoplasia, occurring in 40-60% of all cutaneous melanoma. BRAF is a serine/threonine protein kinase which is an essential part of the mitogen-activated protein kinase (MAPK) pathway. It is physiologically activated by RAS, but in mutated form, due to molecular conformational change, BRAF becomes constitutively active with subsequent persistent activation of downstream cytoplasmic and nuclear proteins (MEK, ERK, ETS), which finally leads to gene expression that promotes cell growth and survival. Inhibition of the altered MAPK pathway by BRAF inhibitors and combined BRAF/MEK inhibitors in BRAF mutated melanoma has become a standard therapeutic approach (1,2). We recently reported the frequency and clinicopathological features of BRAF V600E mutated melanomas in the Dalmatian region of Croatia. This report included 80 cutaneous melanomas with BRAF analyses performed at our institution until the second half of 2017, using a kit which detected only BRAF V600E mutation (3). From the second half of 2017, we started using a kit which detects several types of BRAF mutations along with NRAS mutation. The aim of this report was to determine the spectrum and frequency of different BRAF mutations in a group of skin melanomas in the Dalmatian region of Croatia and to comment on the relationship between type of BRAF mutation and therapeutic response to MAPK pathway inhibition. The analysis included 179 patients with stage 3 and stage 4 cutaneous melanoma with known BRAF/NRAS mutational status. The paraffin blocks were forwarded from four Dalmatian hospitals (Split: 139 cases, Zadar: 17 cases, Sibenik: 13 cases, Dubrovnik: 10 cases). BRAF/NRAS mutation analysis was performed at the Institute of Pathology, Clinical Hospital Center Split, Croatia, in the period from the second half of 2017 to the end of 2022. For DNA extraction analysis, hematoxylin and eosin stained slides from each submitted sample were reviewed by a pathologist, and tumor tissue was identified for analysis. For all tissue specimens, DNA was extracted from sections (10 mm thick) using the cobas® DNA Sample Preparation Kit (Roche Molecular Diagnostics), following the manufacturer's protocol. The amount of genomic DNA was quantified using the Qubit® 2.0 Fluorometer (Life Technologies) and adjusted to a fixed concentration to be added to the amplification/detection mixture. For mutation analysis, the target DNA was amplified and detected on the cobas z 480 analyzer using the amplification and detection reagents provided in the Roche BRAF/NRAS mutation test (LSR) kit, according to the manufacturer's protocol. The test results were reported as follows: BRAF exon 11 mutation detected, BRAF V600E/E2/D mutation detected, BRAF V600K mutation detected, BRAF V600R mutation detected, BRAF K601E mutation detected, NRAS (G12X, G13X, A18T, Q61X, other NRAS Ex3/4) mutation detected, mutation not detected, or invalid result (no result was obtained on the cobas test). BRAF mutation was observed in 87 patients (48.6%), NRAS mutation was found in 27 patients (15.1%), while 65 patients (36.3%) were without BRAF/NRAS mutation (Table 1). In the group of BRAF mutated melanomas, 61 cases (70.1%) had V600E/E2/D mutation, 20 cases (23%) had V600K mutation, 3 cases (3.4%) had exon 11 mutation, 2 cases (2.3%) had V600R mutation, and 1 case (1.2%) had K601E mutation (Table 2). The observed frequency of BRAF mutated melanomas in this study was similar to the frequency reported in our previous study (48.6% and 47.5%, respectively) (3). The vast majority were BRAF V600 mutations, while BRAF non-V600 mutations were rare (95.4% and 4.6%, respectively). In the group of BRAF V600 mutations, V600E/E2/D mutations predominated, followed by V600K mutations, while V600R mutations were rare. Greaves et al. reported similar frequency of BRAF V600 mutations in a group of 499 BRAF-mutated cutaneous melanomas, with V600E/E2/D mutations observed in 77.2% cases, followed by V600K mutations observed in 17.2% cases, and V600R mutations observed in 2.6% cases (4). BRAF non-V600 mutations (exon 11 and K601E mutations) were rarely observed in this study, confirming the findings of other authors (4,5). A three-class system of BRAF mutations was recently proposed that takes into account the differences in their kinase activity, with class I containing mutants with high kinase activity and high response rate to BRAF and BRAF/MEK inhibitors. Class II BRAF mutations have lower kinase activity than class I mutants, but higher than wild-type BRAF, showing resistance to BRAF inhibitor monotherapy and sensitivity to MEK and BRAF/MEK inhibitors. Finally, class III BRAF mutations are characterized by low kinase activity and low response rate to targeted therapy (6). BRAF V600 mutations belong to class I mutations, which means that the large majority of BRAF-positive melanomas in this study (95.4%) were sensitive to targeted therapy. However, the sensitivity to targeted therapy is different among different class I BRAF mutations. While large randomized controlled trials on combined BRAF/MEK inhibition showed good overall response (63-68%) and improvement of progression-free survival (PFS) and overall survival (OS) for the melanomas with most prevalent V600E and V600K mutations, Menzer et al. showed lower response rate to MAPK pathway inhibition (45%) in the group of metastatic melanomas with BRAF V600 mutations other than V600E/K. The overall response rate to MAPK pathway inhibition in the same group of melanomas with BRAF non-V600 mutations (class II and III mutations) was only 18% (7). In our group of BRAF mutated skin metastatic melanomas, we found only 6 cases (6.9%) with expected lower response rate to MAPK pathway inhibition: 2 cases with V600R mutation (class I non-V600E/K mutation), 1 case with K601E mutation (class II mutation), and 3 cases with exon 11 mutation (class II and III mutations).

Regorafenib synergizes with TAS102 against multiple gastrointestinal cancers and overcomes cancer stemness, trifluridine-induced angiogenesis, ERK1/2 and STAT3 signaling regardless of KRAS or BRAF mutational status.

Single-agent TAS102 (trifluridine/tipiracil) and regorafenib are FDA-approved treatments for metastatic colorectal cancer (mCRC). We previously reported that regorafenib combined with a fluoropyrimidine can delay disease progression in clinical case reports of multidrug-resistant mCRC patients. We hypothesized that the combination of TAS102 and regorafenib may be active in CRC and other gastrointestinal (GI) cancers and may in the future provide a treatment option for patients with advanced GI cancer. We investigated the therapeutic effect of TAS102 in combination with regorafenib in preclinical studies employing cell culture, colonosphere assays that enrich for cancer stem cells, and in vivo. TAS102 in combination with regorafenib has synergistic activity against multiple GI cancers in vitro including colorectal and gastric cancer, but not liver cancer cells. TAS102 inhibits colonosphere formation and this effect is potentiated by regorafenib. In vivo anti-tumor effects of TAS102 plus regorafenib appear to be due to anti-proliferative effects, necrosis and angiogenesis inhibition. Growth inhibition by TAS102 plus regorafenib occurs in xenografted tumors regardless of p53, KRAS or BRAF mutations, although more potent tumor suppression was observed with wild-type p53. Regorafenib significantly inhibits TAS102-induced angiogenesis and microvessel density in xenografted tumors, as well inhibits TAS102-induced ERK1/2 activation regardless of RAS or BRAF status in vivo. TAS102 plus regorafenib is a synergistic drug combination in preclinical models of GI cancer, with regorafenib suppressing TAS102-induced increase in microvessel density and p-ERK as contributing mechanisms. The TAS102 plus regorafenib drug combination may be further tested in gastric and other GI cancers.

Novel drug resistance mechanisms and drug targets in BRAF-mutated peritoneal metastasis from colorectal cancer.

BACKGROUND: Patients with peritoneal metastasis from colorectal cancer (PM-CRC) have inferior prognosis and respond particularly poorly to chemotherapy. This study aims to identify the molecular explanation for the observed clinical behavior and suggest novel treatment strategies in PM-CRC. METHODS: Tumor samples (230) from a Norwegian national cohort undergoing surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) with mitomycin C (MMC) for PM-CRC were subjected to targeted DNA sequencing, and associations with clinical data were analyzed. mRNA sequencing was conducted on a subset of 30 samples to compare gene expression in tumors harboring BRAF or KRAS mutations and wild-type tumors. RESULTS: BRAF mutations were detected in 27% of the patients, and the BRAF-mutated subgroup had inferior overall survival compared to wild-type cases (median 16 vs 36 months, respectively, p < 0.001). BRAF mutations were associated with RNF43/RSPO aberrations and low expression of negative Wnt regulators (ligand-dependent Wnt activation). Furthermore, BRAF mutations were associated with gene expression changes in transport solute carrier proteins (specifically SLC7A6) and drug metabolism enzymes (CES1 and CYP3A4) that could influence the efficacy of MMC and irinotecan, respectively. BRAF-mutated tumors additionally exhibited increased expression of members of the novel butyrophilin subfamily of immune checkpoint molecules (BTN1A1 and BTNL9). CONCLUSIONS: BRAF mutations were frequently detected and were associated with particularly poor survival in this cohort, possibly related to ligand-dependent Wnt activation and altered drug transport and metabolism that could confer resistance to MMC and irinotecan. Drugs that target ligand-dependent Wnt activation or the BTN immune checkpoints could represent two novel therapy approaches.

KRAS and BRAF genetic alterations in lung cancer: A case - control study.

CONTEXT: Lung cancer (LC) is one of the most critical neoplastic abnormalities, having globally a high mortality rate. Knowledge about its genetic mutations and their association with clinically pathological features of LC is very important. Here, we describe the epidemiological molecular study of genetic mutations in KRAS and BRAF genes and their relationship with the demographic and clinical characteristics of Pakistani patients with lung adenocarcinoma. AIM: To analyze the mutations of KRAS and BRAF in LC patients among Pakistani population. SETTINGS AND DESIGN: The study has been carried out at universities and health institutes of Islamabad, Pakistan. METHODS AND MATERIAL: Deoxyribonucleic acid (DNA) was extracted from the patient samples by using the standard protocol and amplified by using the specific primers. Later on, the Polymerase Chain Reaction (PCR) products were examined with the help of single stranded conformational polymorphism (SSCP). STATISTICAL ANALYSIS: Relationship between KRAS, BRAF mutations, and LC risk was accessed by conditional logistic regression using SPSS version 24.0. Results were illustrated by odds ratio (OR), 95% confidence interval (CI), and P value. RESULTS: LC is more common in male population and smoking is one of the leading risk factors for (p < 0.0001) LC. KRAS and BRAF mutations were found to be contributing factors toward LC development and showed statistically significant results along with conformation through computational analysis. CONCLUSIONS: It can be concluded that smoking is lethal and cancer causing. The concomitant mutations found in KRAS and BRAF were infrequent, and they probably have a very unusual effect on the clinical management of Pakistani patients with lung adenocarcinoma.

[Clinicopathological features and prognosis of sporadic mismatch repair deficient colorectal cancer].

Objective: To investigate the clinicopathological characteristics and prognostic factors of sporadic mismatch repair deficient (dMMR) colorectal cancer. Methods: A total of 120 cases of sporadic dMMR colorectal cancer from July 2015 to April 2021 were retrospectively collected in Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. Patients with Lynch syndrome; synchronous multiple colorectal cancers; preoperative anti-tumor treatments such as chemotherapy and radiotherapy; and those with incomplete follow-up information were excluded based on family history and next-generation sequencing (NGS) test results. Immunohistochemical stains were used to detect the expression of mismatch repair proteins, methylation-specific PCR for methylation testing, and fluorescent PCR for BRAF V600E gene mutation detection. The clinical and pathological data, and gene mutation status were analyzed. Follow-up was done to assess survival and prognosis including progression-free survival and overall survival rate. Results: Sporadic dMMR colorectal cancer occurred more frequently in the right side of the colon, in females, and in the elderly. Morphologically, it was mostly moderately-differentiated, and most patients had low-grade tumor budding. In terms of immunohistochemical expression, MLH1 and PMS2 loss were dominant, and there were age and location-specificities in protein expression. MLH1 methylation was commonly detected in elderly female patients and rare in young male patients; while MLH1 and PMS2 deficiency, and BRAF V600E mutation occurred more often on the right side (P<0.05). The 3-year and 5-year progression-free survival rates were 90.7% and 88.7% respectively, and the 3-year and 5-year overall survival rates were 92.8% and 90.7% respectively. Tumor budding status was an independent risk factor affecting patient recurrence (hazard ratio=3.375, 95% confidence interval: 1.060-10.741, P=0.039), patients with low-grade tumor budding had better prognosis, and those with medium or high-grade tumor budding had poor prognosis. Conclusion: For dMMR colorectal cancer patients, tumor budding status is an independent risk factor for recurrence.

Efficacy of chemotherapy plus immune checkpoint inhibitors in patients with non-small cell lung cancer who have rare oncogenic driver mutations: a retrospective analysis.

BACKGROUND: Targeted therapy is now the standard of care in driver-oncogene-positive non-small cell lung cancer (NSCLC). Its initial clinical effects are remarkable. However, almost all patients experience treatment resistance to targeted therapy. Hence, chemotherapy is considered a subsequent treatment option. In patients with driver-oncogene-negative NSCLC, combined immune checkpoint inhibitors (ICIs) and chemotherapy as the first-line therapy has been found to be beneficial. However, the efficacy of ICI plus chemotherapy against driver-oncogene-positive NSCLC other than epidermal growth factor receptor mutation and anaplastic lymphoma kinase fusion is unclear. METHODS: Using the hospital medical records, we retrospectively reviewed advanced or recurrent NSCLC patients who were treated with chemotherapy with or without ICIs at Aichi Cancer Center Hospital between January 2014 and January 2023. Patients with druggable rare mutations such as KRAS-G12C, MET exon 14 skipping, HER2 20 insertion, BRAF-V600E mutations, and ROS1 and RET rearrangements were analyzed. RESULTS: In total, 61 patients were included in this analysis. ICI plus chemotherapy was administered in 36 patients (the ICI-chemo group) and chemotherapy in 25 patients (the chemo group). The median progression-free survival (PFS) rates were 14.0 months in the ICI-chemo group and 4.8 months in the chemo group (hazard ratio [HR] = 0.54, 95% confidence interval [CI] = 0.28-1.01). The median overall survival rates were 31.3 and 21.7 months in the ICI-chemo and chemo groups, respectively (HR = 0.70, 95% CI = 0.33-1.50). Multivariate Cox regression analysis of PFS revealed that HER2 exon 20 insertion mutation was significantly associated with a poorer PFS (HR: 2.39, 95% CI: 1.19-4.77, P = 0.014). Further, ICI-chemo treatment was significantly associated with a better PFS (HR: 0.48, 95% CI: 0.25-0.91, P = 0.025). CONCLUSION: ICI plus chemotherapy improves treatment efficacy in rare driver-oncogene-positive NSCLC.

Rapid but nondurable response of a BRAF exon 15 double-mutated spindle cell sarcoma to a combination of BRAF and MEK inhibitors.

INTRODUCTION: BRAF V600E substitution predicts sensitivity of a cancer to BRAF inhibitor therapy. The mutation is rarely found in soft-tissue sarcomas. Here we describe a case of undifferentiated spindle cell sarcoma showing primary insensitivity to standard chemotherapy and pronounced but non-sustained response to BRAF/MEK inhibitors at recurrence. CASE PRESENTATION: A 13-year-old girl was diagnosed with low-grade spindle cell sarcoma of pelvic localization, BRAF exon 15 double-mutated: c.1799T>A p.V600E and c.1819T>A p.S607T in cis-position. The tumor showed resistance to CWS-based first-line chemotherapy and was treated surgically by radical resection. Seven months after surgery the patient developed metastatic relapse with abdominal carcinomatosis. Combined targeted therapy with BRAF/MEK inhibitors afforded complete response in 1 month and was continued, though complicated by severe side effects (fever, rash) necessitating 1-2 week toxicity breaks. After 4 months from commencement the disease recurred and anti-BRAF/MEK regimen consolidation was unsuccessful. Intensive salvation chemotherapy was ineffective. Empirical immunotherapy afforded a transient partial response giving way to fatal progression with massive, abdominal cocoon-complicated peritoneal carcinomatosis. CONCLUSION: This is the first report of spindle cell sarcoma BRAF V600E/S607T double-mutated, responding to a combination of B-Raf and MEK inhibitors. Despite the low histological grade and radical surgical treatment of the tumor at primary manifestation, the disease had aggressive clinical course and the response to BRAF/MEK targeted therapy at recurrence was complete but nondurable. Empirical use of pembrolizumab provided no unambiguous evidence on the clinical relevance of immunotherapy in protein kinase -rearranged spindle cell tumors.

Targeting the multifaceted BRAF in cancer: New directions.

Activating mutations in the mitogen-activated protein kinase (MAPK) pathway represent driver alterations governing tumorigenesis, metastasis, and therapy resistance. MAPK activation predominantly occurs through genomic alterations in RAS and BRAF. BRAF is an effector kinase that functions downstream of RAS and propagates this oncogenic activity through MEK and ERK. Across cancers, BRAF alterations include gain-of-function mutations, copy-number alterations, and structural rearrangements. In cancer patients, BRAF-targeting precision therapeutics are effective against Class I BRAF alterations (p.V600 hotspot mutations) in tumors such as melanomas, thyroid cancers, and colorectal cancers. However, numerous non-Class I BRAF inhibitors are also in development and have been explored in some cancers. Here we discuss the diverse forms of BRAF alterations found in human cancers and the strategies to inhibit them in patients harboring cancers of distinct origins.

Unraveling morphology, methylation profiling, and diagnostic challenges in BRAF-Mutant pediatric glial and glioneuronal tumors.

OBJECTIVES: To elucidate the relationship between DNA methylation profiling (DMP) and pathological diagnosis (PD) in pediatric glial and glioneuronal tumors with B-Raf proto-oncogene, serine/threonine kinase (BRAF) mutations, addressing their diagnostic challenges. METHODS: This retrospective study, conducted in Saudi Arabia, analyzed 47 cases from the Children's Brain Tumor Network online database using scanned images, next-generation sequencing data, and methylation profiles processed using the Heidelberg methylation brain tumor classifiers v12.5 and v12.8. The data was last access on 10 November 2023. RESULTS: The highest prevalence of BRAF mutations was observed in pilocytic astrocytoma and ganglioglioma. The DMP was consistent with PD in 23 cases, but discrepancies emerged in others, including diagnostic changes in diffuse leptomeningeal glioneuronal tumor and polymorphous low-grade neuroepithelial tumor of the young. A key inconsistency appeared between a pilocytic astrocytoma MC and a glioneuronal tumor PD. Two high-grade astrocytomas were misclassified as pleomorphic xanthoastrocytomas. Additionally, low variant allelic frequency in gangliogliomas likely contributed to misclassifications as control in 5 cases. CONCLUSION: This study emphasized the importance of integrating DMP with PD in diagnosing pediatric glial and glioneuronal tumors with BRAF mutations. Although DMP offers significant diagnostic insights, its limitations, particularly in cases with low tumor content, necessitate cautious interpretation, as well as its use as a complementary diagnostic tool, rather than a definitive method.

Polyamine and EIF5A hypusination downstream of c-Myc confers targeted therapy resistance in BRAF mutant melanoma.

BACKGROUND: BRAF inhibitors are widely employed in the treatment of melanoma with the BRAF V600E mutation. However, the development of resistance compromises their therapeutic efficacy. Diverse genomic and transcriptomic alterations are found in BRAF inhibitor resistant melanoma, posing a pressing need for convergent, druggable target that reverse therapy resistant tumor with different resistance mechanisms. METHODS: CRISPR-Cas9 screens were performed to identify novel target gene whose inhibition selectively targets A375VR, a BRAF V600E mutant cell line with acquired resistance to vemurafenib. Various in vitro and in vivo assays, including cell competition assay, water soluble tetrazolium (WST) assay, live-dead assay and xenograft assay were performed to confirm synergistic cell death. Liquid Chromatography-Mass Spectrometry analyses quantified polyamine biosynthesis and changes in proteome in vemurafenib resistant melanoma. EIF5A hypusination dependent protein translation and subsequent changes in mitochondrial biogenesis and activity were assayed by O-propargyl-puromycin labeling assay, mitotracker, mitoSOX labeling and seahorse assay. Bioinformatics analyses were used to identify the association of polyamine biosynthesis with BRAF inhibitor resistance and poor prognosis in melanoma patient cohorts. RESULTS: We elucidate the role of polyamine biosynthesis and its regulatory mechanisms in promoting BRAF inhibitor resistance. Leveraging CRISPR-Cas9 screens, we identify AMD1 (S-adenosylmethionine decarboxylase 1), a critical enzyme for polyamine biosynthesis, as a druggable target whose inhibition reduces vemurafenib resistance. Metabolomic and proteomic analyses reveal that polyamine biosynthesis is upregulated in vemurafenib-resistant cancer, resulting in enhanced EIF5A hypusination, translation of mitochondrial proteins and oxidative phosphorylation. We also identify that sustained c-Myc levels in vemurafenib-resistant cancer are responsible for elevated polyamine biosynthesis. Inhibition of polyamine biosynthesis or c-Myc reversed vemurafenib resistance both in vitro cell line models and in vivo in a xenograft model. Polyamine biosynthesis signature is associated with poor prognosis and shorter progression free survival after BRAF/MAPK inhibitor treatment in melanoma cohorts, highlighting the clinical relevance of our findings. CONCLUSIONS: Our findings delineate the molecular mechanisms involving polyamine-EIF5A hypusination-mitochondrial respiration pathway conferring BRAF inhibitor resistance in melanoma. These targets will serve as effective therapeutic targets that can maximize the therapeutic efficacy of existing BRAF inhibitors.

Immuno-oncologic profiling of pediatric brain tumors reveals major clinical significance of the tumor immune microenvironment.

With the success of immunotherapy in cancer, understanding the tumor immune microenvironment (TIME) has become increasingly important; however in pediatric brain tumors this remains poorly characterized. Accordingly, we developed a clinical immune-oncology gene expression assay and used it to profile a diverse range of 1382 samples with detailed clinical and molecular annotation. In low-grade gliomas we identify distinct patterns of immune activation with prognostic significance in BRAF V600E-mutant tumors. In high-grade gliomas, we observe immune activation and T-cell infiltrates in tumors that have historically been considered immune cold, as well as genomic correlates of inflammation levels. In mismatch repair deficient high-grade gliomas, we find that high tumor inflammation signature is a significant predictor of response to immune checkpoint inhibition, and demonstrate the potential for multimodal biomarkers to improve treatment stratification. Importantly, while overall patterns of immune activation are observed for histologically and genetically defined tumor types, there is significant variability within each entity, indicating that the TIME must be evaluated as an independent feature from diagnosis. In sum, in addition to the histology and molecular profile, this work underscores the importance of reporting on the TIME as an essential axis of cancer diagnosis in the era of personalized medicine.

Feasibility and Impact of Embedding an Extended DNA and RNA Tissue-Based Sequencing Panel for the Routine Care of Patients with Advanced Melanoma in Spain.

Targeted NGS allows a fast and efficient multi-gene analysis and the detection of key gene aberrations in melanoma. In this study, we aim to describe the genetic alterations in a series of 87 melanoma cases using the oncomine focus assay (OFA), relate these results with the clinicopathological features of the patients, and compare them with our previous study results in which we used a smaller panel, the oncomine solid tumor (OST) DNA kit. Patients diagnosed with advanced melanoma at our center from 2020 to 2022 were included and DNA and RNA were extracted for sequencing. Common mutated genes were BRAF (29%), NRAS (28%), ALK, KIT, and MAP2K1 (5% each). Co-occurring mutations were detected in 29% of the samples, including BRAF with KIT, CTNNB1, EGFR, ALK, HRAS, or MAP2K1. Amplifications and rearrangements were detected in 5% of cases. Only BRAF mutation showed a significant statistical association with sun exposure. For patients with a given genetic profile, the melanoma survival and recurrence-free survival rates were equivalent, but not for stage and LDH values. This expanded knowledge of molecular alterations has helped to more comprehensively characterize our patients and has provided relevant information for deciding the best treatment strategy.

Prediction of the Aggressive Clinical Course of Papillary Thyroid Carcinoma Based on Fine Needle Aspiration Biopsy Molecular Testing.

Molecular genetic events are among the numerous factors affecting the clinical course of papillary thyroid carcinoma (PTC). Recent studies have demonstrated that aberrant expression of miRNA, as well as different thyroid-related genes, correlate with the aggressive clinical course of PTC and unfavorable treatment outcomes, which opens up new avenues for using them in the personalization of the treatment strategy for patients with PTC. In the present work, our goal was to assess the applicability of molecular markers in the preoperative diagnosis of aggressive variants of papillary thyroid cancer. The molecular genetic profile (expression levels of 34 different markers and BRAF mutations) was studied for 108 cytology specimens collected by fine-needle aspiration biopsy in patients with PTC having different clinical manifestations. Statistically significant differences with adjustment for multiple comparisons (p < 0.0015) for clinically aggressive variants of PTC were obtained for four markers: miRNA-146b, miRNA-221, fibronectin 1 (FN1), and cyclin-dependent kinase inhibitor 2A (CDKN2A) genes. A weak statistical correlation (0.0015 < p < 0.05) was observed for miRNA-31, -375, -551b, -148b, -125b, mtDNA, CITED1, TPO, HMGA2, CLU, NIS, SERPINA1, TFF3, and TMPRSS4. The recurrence risk of papillary thyroid carcinoma can be preoperatively predicted using miRNA-221, FN1, and CDKN2A genes.

Modeling Extraordinary Response Through Targeting Secondary Alterations in Fusion-Associated Sarcoma.

PURPOSE: Targeted therapy in translocation-associated sarcomas has been limited to oncogenic activation of tyrosine kinases or ligands while gene fusions resulting in aberrant expression of transcription factors have been notoriously difficult to target. Moreover, secondary genetic alterations in sarcomas driven by translocations are uncommon, comprising mostly alterations in tumor suppressor genes (TP53, CDKN2A/B). Our study was triggered by an index patient showing a dramatic clinical response by targeting the secondary BRAF V600E mutation in a metastatic angiomatoid fibrous histiocytoma (AFH) harboring the typical EWSR1::CREB1 fusion. MATERIALS AND METHODS: The patient, a 28-year-old female, was diagnosed with an AFH of the thigh and followed a highly aggressive clinical course, with rapid multifocal local recurrence within a year and widespread distant metastases (adrenal, bone, liver, lung). The tumor showed characteristic morphologic features, with histiocytoid cells intermixed with hemorrhagic cystic spaces and lymphoid aggregates. In addition to the pathognomonic EWSR1::CREB1 fusion, targeted DNA sequencing revealed in both primary and adrenal metastatic sites a hot spot BRAF V600E mutation and a CDKN2A/B deletion. Accordingly, the patient was treated with a BRAF-MEK inhibitor combination (encorafenib/binimetinib) showing an excellent but short-lived response. RESULTS: Using a CRISPR-Cas9 approach, we introduced the BRAF c.1799 T>A point mutation in human embryonic stem (hES) cells harboring a conditional EWSR1 (exon7)::CREB1 (exon7) translocation and further differentiated to mesenchymal progenitors (hES-MP) before fusion expression. The cells maintained the fusion transcript expression and the AFH core gene signature while responding to treatment with encorafenib and binimetinib. CONCLUSION: These results highlight that additional targeted DNA NGS in chemotherapy-resistant translocation-associated sarcomas may reveal actionable oncogenic drivers occurring as secondary genetic events during disease progression.

Targeted sequencing of DNA/RNA combined with radiomics predicts lymph node metastasis of papillary thyroid carcinoma.

OBJECTIVE: The aim of our study is to find a better way to identify a group of papillary thyroid carcinoma (PTC) with more aggressive behaviors and to provide a prediction model for lymph node metastasis to assist in clinic practice. METHODS: Targeted sequencing of DNA/RNA was used to detect genetic alterations. Gene expression level was measured by quantitative real-time PCR, western blotting or immunohistochemistry. CCK8, transwell assay and flow cytometry were used to investigate the effects of concomitant gene alterations in PTC. LASSO-logistics regression algorithm was used to construct a nomogram model integrating radiomic features, mutated genes and clinical characteristics. RESULTS: 172 high-risk variants and 7 fusion types were detected. The mutation frequencies in BRAF, TERT, RET, ATM and GGT1 were significantly higher in cancer tissues than benign nodules. Gene fusions were detected in 16 samples (2 at the DNA level and 14 at the RNA level). ATM mutation (ATMMUT) was frequently accompanied by BRAFMUT, TERTMUT or gene fusions. ATMMUT alone or ATM co-mutations were significantly positively correlated with lymph node metastasis. Accordingly, ATM knock-down PTC cells bearing BRAFV600E, KRASG12R or CCDC6-RET had higher proliferative ability and more aggressive potency than cells without ATM knock-down in vitro. Furthermore, combining gene alterations and clinical features significantly improved the predictive efficacy for lymph node metastasis of radiomic features, from 71.5 to 87.0%. CONCLUSIONS: Targeted sequencing of comprehensive genetic alterations in PTC has high prognostic value. These alterations, in combination with clinical and radiomic features, may aid in predicting invasive PTC with higher accuracy.

A new BRAF inhibitor breaks resistance barriers.

Approved BRAF inhibitors have shown limited clinical benefit due to recurrent disease progression. In a recent Cancer Discovery paper, Yaeger et al. show that a next-generation BRAF inhibitor, PF-07799933, has widespread therapeutic activity in experimental models and patients who were refractory to treatment with approved BRAF inhibitors.

[A Case of BRAF Mutant Cecal Cancer Treated with Encorafenib, Binimetinib, and Cetuximab Triple Therapy].

A Japanese woman in her early 70's presented to our hospital with abdominal pain and nausea. Abdominal computed tomography showed irregular wall thickening of the ileocecal region and small intestine dilatation. Colonoscopy revealed a tumor lesion at the ileocecal valve and adenocarcinoma was detected in the biopsy specimen. Accordingly, the diagnosis was cecal cancer and bowel obstruction. Right hemicolectomy was performed as palliative surgery, and laparotomy findings revealed peritoneal dissemination. The final staging was pT4a, pN2b, pM1c, pStage Ⅳc, harboring a BRAFV600E mutation. Rapid postoperative tumor progression occurred, leading to multiple liver metastases and ascites. Encorafenib, binimetinib, and cetuximab triple therapy was started as a second line regimen. The therapy was extremely effective. CA19-9 level decreased to within normal range, and the liver tumor size was visibly diminished. After receiving treatment for 2 months in outpatient care, she had to discontinue the treatment due to carcinomatous peritonitis. Unfortunately, she died 6 months after initial diagnosis. BRAF-mutated colon cancer is associated with poor prognosis. In Japan, encorafenib, binimetinib, and cetuximab triple therapy is a new BRAF targeting regimen approved in 2020. We report this clinical course in hopes of eventually achieving better outcomes for patients with this aggressive disease.

Progress in clinical diagnosis and treatment of colorectal cancer with rare genetic variants.

Targeted therapy is crucial for advanced colorectal cancer (CRC) positive for genetic drivers. With advances in deep sequencing technology and new targeted drugs, existing standard molecular pathological detection systems and therapeutic strategies can no longer meet the requirements for careful management of patients with advanced CRC. Thus, rare genetic variations require diagnosis and targeted therapy in clinical practice. Rare gene mutations, amplifications, and rearrangements are usually associated with poor prognosis and poor response to conventional therapy. This review summarizes the clinical diagnosis and treatment of rare genetic variations, in genes including erb-b2 receptor tyrosine kinase 2 (ERBB2), B-Raf proto-oncogene, serine/threonine kinase (BRAF), ALK receptor tyrosine kinase/ROS proto-oncogene 1, receptor tyrosine kinase (ALK/ROS1), neurotrophic receptor tyrosine kinases (NTRKs), ret proto-oncogene (RET), fibroblast growth factor receptor 2 (FGFR2), and epidermal growth factor receptor (EGFR), to enhance understanding and identify more accurate personalized treatments for patients with rare genetic variations.

Research progress of ectopic thyroid cancer in thyroglossal duct cyst: A case report and literature review.

RATIONALE: Thyroglossal duct carcinoma, a rare clinical condition characterized by ectopic thyroid adenocarcinoma within thyroglossal duct cysts (TGDCs), typically confirmed through intraoperative rapid pathology, this condition generally has a favorable prognosis. Nevertheless, comprehensive treatment guidelines across all disease stages are lacking, the purpose of this study is to report 1 case of the disease and propose the treatment plan for each stage of the disease. PATIENT CONCERNS: A patient presented with thyroid swelling, classified as C-TIRADS 4A following a physical examination. Preoperative thyroid puncture identified papillary thyroid carcinoma, and genetic testing revealed a BRAF gene exon 15-point mutation. Ancillary tests showed a slightly decreased thyroid stimulating hormone (TSH) level (0.172) with no other significant abnormalities. DIAGNOSES: Preoperative fine-needle aspiration cytology (FNAC) confirmed right-side thyroid cancer. Intraoperative exploration uncovered a TGDC and intraoperative rapid pathology confirmed thyroglossal duct carcinoma. INTERVENTIONS: A Sistrunk operation and ipsilateral thyroidectomy were performed. OUTCOMES: Postoperative recovery was satisfactory. LESSONS: Thyroglossal duct carcinoma is a rare disease affecting the neck. Due to limited clinical cases and the favorable prognosis associated with this condition, there is currently no established set of diagnostic and treatment guidelines. According to tumor size, lymph node metastasis, thyroid status and other factors, the corresponding treatment methods were established for each stage of thyroglossal duct cancer, which laid the foundation for the subsequent treatment development of this disease.