Positive BRAF Research Articles

8155 Isolated Hypothalamic-Pituitary Langerhans' Cell Histiocytosis in Adult Patients

Abstract Disclosure: A. Vu: None. M. Aguilera: None. J. Shakil: None. R. Al-Ward: None. Introduction: Langerhans cell histiocytosis (LCH) is an infiltrative disease due to clonal proliferation of immature dendritic cells mainly affecting children and seen in adults in less than 30% of cases. It can present as localized or with systemic manifestations, with isolated hypothalamic-pituitary lesions being exceptionally rare. Our report adds to the limited published literature by presenting two cases of isolated hypothalamic-pituitary LCH diagnosed in adults. Furthermore, one of the cases reveals a rare association with papillary thyroid cancer (PTC). Case 1: 35-year-old woman with no past medical history presented with 4 year history of amenorrhea and weight gain and more recently, polyuria and polydipsia. Further investigations showed hypogonadotropic hypogonadism, central hypothyroidism, and mildly elevated prolactin. She couldn’t complete water deprivation test due to extreme thirst. A dedicated pituitary MRI showed marked infundibular enlargement, concerning for hypophysitis. An extensive workup including assessments for autoimmune etiology, sarcoidosis, infections, and low-grade tumors, did not identify a definitive etiology. A PET scan was obtained (to rule out LCH and Erdheim Chester disease), which showed increased uptake in the pituitary stalk. Due to otherwise negative workup, transsphenoidal biopsy of the pituitary lesion was done. Post-procedure, diabetes insipidus (DI) was diagnosed due to elevated sodium while fasting for the procedure. Tissue examination revealed increased histiocytes and lymphocytes, and a positive BRAF V600E mutation confirming LCH as the underlying diagnosis. Case 2: 26-year-old male with history of LCH limited to the skull, in remission for 8 years after chemotherapy, presented with 4-week history of polyuria, polydipsia and weight loss. A 24-hour urine collection resulted in 6.5L of urine. During water deprivation test, there was notable increase in serum sodium, serum osmolarity, and urine osmolarity. Initial pituitary MRI was normal, but subsequent imaging revealed the loss of the posterior pituitary bright spot. PET scan showed focal FDG avidity in the right lower thyroid lobe, confirmed on fine needle aspiration as PTC with BRAF mutation. He underwent total thyroidectomy and is currently receiving chemotherapy for LCH recurrence. Discussion: LCH is infrequent in adults, presenting with variable manifestations based on affected organs. In the multifocal form, the hypothalamic-pituitary axis is involved in 5-50% of cases. Our report describes two unique cases with only four other reported cases of isolated hypothalamic-pituitary axis LCH in adults. Central diabetes insipidus can be seen before the diagnosis or as the disease progresses. Pituitary biopsy, although invasive, should be considered when the diagnosis is not clear. The association of PTC with a BRAF mutation is extremely rare and has been reported. Presentation: 6/2/2024

Papillary microcarcinoma of the thyroid gland: Evaluation of TERT and BRAFV-600E expression and their relationship with clinicopathological findings

Papillary microcarcinomas (PMCs) are papillary carcinomas ≤1 cm in size, with an increasing incidence. Although generally indolent, some cases exhibit aggressive behavior. Recently, active surveillance has been recommended to avoid surgical treatment. Identifying molecular changes that predict aggressiveness in PMCs has gained importance, but studies are limited. We aimed to demonstrate TERT expression and BRAF V600E positivity immunohistochemically in PMCs and correlate them with histomorphological features, subtypes, and clinicopathological findings. We included 95 PMC cases diagnosed between 2010 and 2019 at the Department of Pathology, Faculty of Medicine, XXX University. We investigated TERT expression using RT-PCR. We evaluated BRAF V600E mutation immunohistochemically. We evaluated the relationship between genetic, histomorphological, and clinicopathological findings. In patients with multifocality and those with a tumor size ≥0.5 cm, the frequency of lymph node metastasis was significantly higher. A positive correlation was shown between BRAF V600E positivity and lymph node metastasis, lymphovascular invasion, advanced disease stage, and classical subtype by univariate analyses. We detected TERT expression in 18 of 95 patients (7.8 %). No relationship could be detected between TERT expression alone or combined with BRAF positivity and clinicopathological features. Although TERT mutations are associated with aggressiveness in thyroid cancers, this association was absent in PMCs. The presence of TERT expression was demonstrated in some cases. However, TERT expression could not be associated with clinicopathological findings, which is consistent with the literature suggesting that TERT plays a role in advanced stages of carcinogenesis.

Superficial Wnt-Activated Melanocytic Nevi/Melanocytomas With a Junctional Component: A Case Series.

The conventional morphological characteristics of Wnt-activated deep penetrating/plexiform melanocytomas/nevi (DPN) are those of large spindled or epithelioid melanocytes with distinctive voluminous amphophilic cytoplasm, fine pigmented granules, and surrounding melanophages. The central molecular hallmark is the activation of the Wnt-pathway predominantly driven by mutations in the beta-catenin ( CTNNB1 ) gene. Although typically lacking a junctional component, a lesser-known superficial variant with a junctional component has been identified, which could potentially lead to diagnostic challenges. This study presents a cohort of 11 such cases displaying a junctional component of DPN from 10 patients (5 women and 5 men; age range: 27-78 years; median age: 51 years). The nevi were distributed as follows: 1 conjunctival, 1 scalp, 2 lower limb, and 6 truncal lesions. Eight cases were combined with a conventional nevus, 2 cases displayed pure DPN cytology exhibiting only a junctional element, and 9 cases exhibited some degree of lentiginous architecture. All cases demonstrated a low mitotic index (<1 mitosis/mm 2 ). Immunohistochemistry revealed positive BRAF V600E staining in 8 cases (8/11), whereas all cases tested (11/11) were PRAME negative. Nuclear beta-catenin and LEF1 staining was consistently strong and diffuse with DPN cytology (11/11), along with robust cyclin D1 staining in all cases tested (11/11). By contrast, all 9 conventional nevi showed an absence of nuclear beta-catenin staining (0/9) and weaker, mosaic-type LEF1 and cyclin D1 staining was observed. This study emphasizes the diagnostic challenge these nevi can pose in the absence of a conventional, deeper DPN component, which can potentially be misdiagnosed as melanoma.

Analysis of Immunohistochemical Expression of BRAF (V600E) Mutation in Serrated Colorectal Polyps: A Study from Tertiary Hospital in Oman.

Colorectal cancer (CRC) is considered one of the most common cancers in the world. Serrated polyps were found to be precursor lesions for CRC. BRAF mutation (V600E) has been strongly linked to the development of these lesions. No previous study concerning BRAF immunohistochemical expression in serrated polyps- was done in Oman. The primary objective of our study was to assess the prevalence of BRAF (V600E) mutation in serrated colorectal polyps in the Omani population. The secondary objectives were to assess the prevalence of serrated polyps and their characteristic features: type, site and size as well as the relationship between BRAF (V600E) mutation and polyp type, site and size. Ninety-one hyperplastic polyps (HP) (76.5%), 24 sessile serrated lesions (SSL) (20.2%) and 4 cases of tubular adenomas with low grade dysplasia (3.4%) were studied for BRAF (V600E) immunohistochemical expression. No case of traditional serrated adenoma (TSA) was present. Control cases of craniopharyngioma and papillary thyroid carcinoma were included. BRAF (V600E) IHC was positive in 63 of the HP polyps (69.2%), 13 SSLs (54.2%) and none of the adenomatous polyps. The majority of positive polyps (75.0%) were ≤5 mm in size, 17.9% were 5-10 mm and 7.1% were ≥10 mm in size. The majority of BRAF (V600E) positive polyps (68.1 %) were in the distal colon and 31.9 % were in the proximal colon. The majority of positive cases for BRAF (V600E) were showing multiple polyps (61.8 %). None of the tubular adenomas showed any BRAF (V600E) positivity. Serrated polyps are now well known for their potential to develop CRC. Immunohistochemistry is an easy and reproducible way to detect BRAF (V600E) mutation. Our study showed there is high prevalence (64.3%) of BRAF mutation in serrated polyps in the Omani population. The majority of these polyps- were HP and SSL; and ≤5 mm in size and located in the distal colon.

Ipilimumab and nivolumab plus UV1, an anticancer vaccination against telomerase, in advanced melanoma.

LBA9519 Background: The combination of ipilimumab (IPI) and nivolumab (NIVO) remains a standard of care for patients with advanced melanoma, especially those with poor prognostic factors, albeit with a significant risk of toxicity. Therapeutic cancer vaccines are ideally positioned to improve outcomes without significantly increasing toxicity. UV1 is a therapeutic cancer vaccine generating T-cell responses against the universal cancer antigen telomerase. In a Phase I trial in melanoma (N = 30), UV1 plus pembrolizumab demonstrated a tolerable safety profile, a complete response rate of 33%, median PFS of 18.9 months, and 2-year OS rate of 73.3%. Recently, results from a randomized Phase II trial indicated a longer overall survival and a higher response rate for previously treated patients with advanced mesothelioma receiving UV1 in combination with IPI-NIVO (1). Methods: In this Phase II, open-label, multicenter study, we randomly assigned treatment-naïve patients with unresectable or metastatic melanoma (stage IIIb-IIId or IV) to IPI 3mg/kg + NIVO 1mg/kg for 4 cycles, followed by NIVO 480 mg as maintenance, with or without 8 intradermal injections of 300 µg UV1 (+GM-CSF). The primary endpoint was progression-free survival (PFS) assessed by blinded independent central review (BICR) according to RECIST 1.1. Secondary endpoints included overall survival (OS), objective response rate (ORR), duration of response, and safety. Results: A total of 156 patients underwent randomization; 78 patients were assigned to the IPI-NIVO-UV1 arm and 78 patients to the IPI-NIVO arm. The median age was 60, 48% had M1C or D disease, 38% had LDH &gt;upper limit of normal, and 42% had a positive BRAF mutation status. With a minimum follow-up of 18 months, the 12-month PFS rate was 57% in both arms (HR 0.95, 95% CI 0.59-1.55, p value 0.845). The ORR was similar with IPI-NIVO-UV1 compared to IPI-NIVO, at 60% vs 59%, respectively (Odds ratio 1.12, 95% CI 0.58-2.16, p value 0.867). The 12-month OS rate was 87% and 88%, respectively (HR 1.15, 95% CI 0.60-2.20, p value 0.674). The occurrence of grade &gt;3 adverse events was similar in both treatment arms. Conclusion: UV1 did not improve on outcomes of IPI-NIVO, in terms of PFS. Longer follow-up is required for the accurate assessment of OS. No significant toxicity increases were observed with the addition of UV1. Data from a biomarker driven cohort are awaited. 1. Helland et al, Eur J Cancer 2024. Clinical trial information: NCT04382664 .

Survival of Patients With Primary Cutaneous Melanoma (Stages 0-IIА and IIB-IIC), Depending on the Presence of the &lt;i&gt;BRAF&lt;/i&gt; Mutation in the Tumor and Surgical Treatment Option

Background: Cutaneous melanoma is an extremely aggressive disease with an unpredictable prognosis. Even among patients with similar tumor parameters and extent of surgical treatment, survival may vary. The extent of surgical resection of primary cutaneous melanoma is well-established, and a BRAF mutation in the tumor is an unfavorable prognostic factor for patient survival. The mutation presence is mainly used as a marker for prescribing targeted therapy. The impact of the extent of surgery and the method for restoring a tissue defect on survival of patients with similar stages remains unexplored. The impact of the BRAF mutation in the tumor on survival of patients with cutaneous melanoma depending on the surgery method has also not been studied. We analyzed the surgical treatment outcomes of 221 patients with primary cutaneous melanoma (stages 0-IIA and IIB-IIC) who were found to have the BRAF mutation and underwent different extents of tumor excision with closure of the surgical tissue defect.Objective: To analyze the impact of the BRAF mutation in the tumor on 5-year survival of patients with primary cutaneous melanoma (stages 0-IIA and IIB-IIC), depending on the extent of surgery and the method of replacing the tissue defect.Materials and methods: We used data from 221 patients with primary cutaneous melanoma (stages 0-IIA and IIB-IIC) and assessed their BRAF mutation status, extent of tumor excision, and method of closing the tissue defect. The patients were divided into 2 groups: the main group (wide excision of the tumor and plastic replacement of the tissue defect) and the comparison group (standard margin and linear closure of the tissue defect). After surgery, all the patients underwent tumor analysis for the BRAF p.V600E/K mutation using real-time PCR. DNA was isolated using the cobas® DNA Sample Preparation Kit on a cobas® z 480 analyzer. We used the following statistical methods: frequency analysis, z test to check the equality, and Kaplan-Meier survival analysis and such software as MedCalc 12.5 (1993-2013, MedCalc Software) and SPSS 26 (IBM Corp, 2019, IBM SPSS Statistics for Windows, Armonk, NY, USA). Results: Wide excision of primary cutaneous melanoma (stages 0-IIA and IIB-IIC) was found to increase 5-year progression-free survival in patients with subsequent plastic replacement of the tissue defect compared with patients with standard margin and linear closure of the tissue defect and 5-year overall survival in patients with stage 0-IIA melanoma. In patients with 0-IIA stage melanoma and positive BRAF mutation test results, wide excision with reconstructive and plastic defect closure improved the 5-year progression-free survival. Conclusions: The 5-year progression-free survival and 5-year overall survival increased by 20.9% (P = .005) and 13.0% (P = .031), respectively, in patients who underwent wide excision of primary cutaneous melanoma followed by plastic replacement of the tissue defect compared with patients with standard excision of primary tumors and linear closure of the tissue defect. The 5-year progression-free survival increased by 23.7% (P = .017) in patients with stage IIB-IIC melanoma, regardless of the BRAF mutation. In patients with 0-IIa stage melanoma and positive BRAF mutation test results who underwent wide excision, the 5-year progression-free survival increased by 20.7% (P = .047) compared with patients who underwent tumor excision with a standard margin.

BRAF-V600E Protein Expression in Canine Malignant Cutaneous Melanoma, in Accordance with the Introduction of Biomarkers in Comparative Oncology Studies

Background: Melanoma is the cause of death for 1.3% of all cancer patients in humans. The key role of the BRAF protein in the progression of human melanoma has been confirmed, and its prognostic significance has been revealed. Because canine cancer resembles human cancer in biological behavior and molecular abnormalities, BRAF protein may be expressed in canine melanoma, the same as human melanoma. Despite the investigation of the BRAF mutation in canine melanoma, the status of BRAF at the protein level in canine skin melanoma has not yet been examined.&#x0D; Methods: Thirty-two formalin-fixed, paraffin-embedded tissue samples of canine malignant cutaneous melanoma were randomly selected. After cutting into 3-μmthick sections, the samples were evaluated for BRAF protein expression by immunohistochemistry and using the anti-BRAF V600E (VE1) mouse monoclonal antibody&#x0D; Results: The BRAF status was assessed using the Allred scoring system. Among the 32 samples examined, 21 samples were negative, and 11 cases showed high BRAF protein expression.&#x0D; Conclusion: The detection of positive BRAF expression in 34.3% of canine cutaneous melanoma samples could be a step forward to improving treatment options, using dogs as an animal model in human melanoma clinical trials, and possibly identifying a new prognostic biomarker in canine melanoma.

SAT516 Impact Of The Braf V600E Gene Mutation In Patients With Papillary Thyroid Cancer From Northern Ecuadorian Andes

Abstract Disclosure: A.P. Solis Pazmiño: None. T. Cardenas: None. J. Cucalon: None. G. Jaramillo-Koupermann: None. G. Galvez: None. C. Reyes: None. J. Salazar- Vega: None. IntroductionThe incidence of thyroid cancer (TC) is increasing worldwide. Most new TC cases are papillary thyroid cancer (PTC). Ideally, the individualization of treatment decisions should not only be based on the context and values of the patient but also on the biology of the tumor. Among them, BRAF V600E + TERT has been associated with aggressive clinic-pathologic outcomes, including tumor recurrence and mortality. The aim of this study was to determine the prevalence of the BRAFV600E mutation in PTC patients from the northern Ecuadorian Andes.MethodsA retrospective cohort study of 193 tumors, was classified according to the TNM system (AJCC 7th edition) and the patients were managed based on the 2015 ATA guidelines from June 2016 to December 2019 in Hospital Eugenio Espejo, Quito-Ecuador. PTC genomic DNA from formalin-fixed, paraffin-embedded tissue was analyzed for exon 15 of the BRAF oncogene by Sanger Sequencing.ResultsFrom 193 patients included, 146 were positive for the mutation (75.6%), and 47 were wild type (24.4%). In the bivariate analysis, the mutation was significantly associated with the presence of distant metastasis (p = 0.02), and it was also a predictor of distant metastasis (odds ratio [OR], 4.1; 95% CI 1.5 - 10.8). There was no significant association between BRAF positivity with demographic variables (age, gender, BMI, altitude), or with tumor characteristics (tumor size, focality, aggressive/nonaggressive variant, lymph node metastases, ACJJ stage, thyroglobulin or iodotherapy values).ConclusionIt has been proposed that patients harboring the mutation be managed more aggressively in the early stages, however, we conclude that the impact of BRAF V600E on PTC is still controversial. To the best of our knowledge, this is the first report of its kind carried out in the Ecuadorian population. Studies involving massive sequencing and prospective clinical correlation are needed in the future. KEYWORDS: Papillary thyroid carcinoma, BRAF V600E mutation, distant metastasis. Presentation Date: Saturday, June 17, 2023

Review of pharmacoeconomic studies of melanoma treatment for the period 2018–2023

When analyzing pharmacoeconomic studies of the skin melanoma treatment conducted in various countries, the combinations of vemurafenib + cobimetinib and encorafenib + binimetinib are the most acceptable therapy options in terms of increasing life expectancy with adjustments for quality, but, according to the clinical guidelines of the National Joint Oncology Network (NCCN), USA, version 2.2023 – “Melanoma: Cutaneous”, not for adjuvant therapy. At the same time, social networks can be a valuable asset of information about patient’s quality of the life. For the patients with advanced melanoma with a BRAF mutation, the combination of atezolizumab + vemurafenib + cobimetinib indicated the highest clinical effectiveness and can be recommended for pharmacotherapy under condition of drug price reduction.Comparison various drugs combinations with monotherapy for patients with unresectable or metastatic melanoma with a positive BRAF V600 mutation indicated that nivolumab + ipilimumab therapy is not cost-effective in comparison with nivolumab monotherapy, but combination of dabrafenib + trametinib, on the contrary, increases the patient's life expectancy compared to vemurafenib and it’s more cost-effective. It was shown that Pembrolizumab to increase life expectancy but it’s associated with increased costs compared to ipilimumab when comparing different monotherapy options. The assumed additional cost-effectiveness factor is acceptable for most European countries, because it does not exceed the “willingness to pay” threshold. It is necessary to conduct large-scale pharma-economic studies in order to identify the most cost-effective treatment for Russia for various variants of the course of melanoma, both of various combined regimens with each other, and their comparison with monotherapy. It is important to take into account also the costs of correcting undesirable adverse drug reactions, since they have a significant impact to the structure of direct costs. The development of innovative drugs for the treatment of melanoma is proceeding rapidly, however, access to these drugs is limited due to their high cost. Patient-centred drug development and reimbursement options need to be found.

Erdheim-Chester disease with bilateral orbital masses and multi-systemic symptoms: two case reports

BackgroundErdheim–Chester disease (ECD) is a rare histiocytic disorder characterized by multisystem xanthogranulomatous infiltration by lipid-laden histiocytes. We report two cases of ECD involving the orbit and describe their clinicopathologic factors, treatments, and prognosis. One was a rare case of ECD complicated with primary thrombocytosis.Case presentationThis study describes two patients with bilateral orbital ECD. Both presented with proptosis and visual loss; imaging findings showed bilateral intraorbital masses. Both had different degrees of systemic symptoms (pleural effusion, pericardial effusion, ascites, and heart failure) before the ocular symptoms and did not find the cause before ophthalmic tumor resection and pathological biopsy. The diagnosis of ECD was confirmed after pathological biopsy and detection of BRAFV600E mutation. Patient 2 also with primary thrombocytosis and had a CALR mutation as well as the BRAFV600E mutation. Both patients were recommended to receive targeted therapy. Patient 1 refused targeted therapy for financial reasons and was discharged after local radiotherapy only. The patient had no light perception in either eye and no improvement in systemic symptoms. Patient 2 began targeted treatment after diagnosis and reached the discharge criteria 2 weeks later. He is in good condition at present, but unfortunately, his eyesight has not improved because of the irreversible damage to his visual function.ConclusionECD is easily misdiagnosed and missed because of its rarity and diverse clinical manifestations. Orbital involvement is common in ECD, and surgery is the most frequently employed approach. Despite the surgical resection is not curative, its significance lies in biopsy to establish diagnosis and/or surgical debulking to relieve mass effect, minimizing further impairment of visual function. Targeted therapy is the most effective treatment for patients with a positive BRAF mutation gene. Evaluation of a concomitant myeloid neoplasm is also critical before initiating targeted therapies for refractory ECD.

Эффективность тройной комбинации в терапии распространенной меланомы

Skin melanoma is one of the most aggressive malignant forms of neoplasms, difficult to treat, has a high potential for growth and dissemination, as well as regional and widespread metastasis. Over the past few years, the issues of efficacy and safety of a number of drugs used to treat patients both in mono mode and in combination therapy regimens have been actively discussed. One notable study on the efficacy of a new drug combination is IMspire150. The use of a triple combination (atezolizumab, vemurafenib, cobimetinib) in the first line of therapy for advanced melanoma with a positive BRAF V600 mutation is presented in this clinical case.

Pathophysiological evaluation of pilocytic astrocytoma in adults: Histopathological and immunohistochemical analysis

Pilocytic astrocytoma is a central nervous system tumor of slow growth, which represents 5 % of all gliomas and most often develops in the cerebellum (42–60 %), but can also arise in other neural areas, such as the optic pathway or hypothalamus (9–30 %); brainstem (9 %); spinal cord (2 %). In the pediatric population, this tumor is the second most common cause of neoplasms and, on the other hand, in adults, it is often rare, probably due to its aggressiveness in these individuals. Studies reveal that the origin of pilocytic astrocytoma is characterized by a fusion between the BRAF gene and the KIAA1549 locus, and the application of the immunohistochemistry technique for the analysis of BRAF protein expression can be a valuable tool for diagnostic purposes. Due to the relative rarity of this disease in adults, there are few publications on the most effective diagnostic and treatment strategies for this tumor. The general objective of this study was to analyze the histopathological and immunohistochemical characteristics of pilocytic astrocytoma in these patients. For this, a retrospective study of patients aged over 17 years with a diagnosis of pilocytic astrocytoma was carried out at the Department of Pathology of UNIFESP/EPM, from 1991 to 2015. In order to define BRAF positivity in the immunohistochemical analysis, at least three consecutive fields with more than 50 % immunostaining were used as criteria and, thus, it was inferred that the 7 cases analyzed were considered positive for the cytoplasmic marker BRAF V600E. Histopathological analysis associated with BRAF immunostaining is of paramount importance as a diagnostic method in these cases. However, future molecular studies will be necessary both for a better understanding of the aggressiveness and prognostic of this tumor and for research involving specific therapies for pilocytic astrocytoma in adults.

PD-L1 Tumor Expression as a Predictive Biomarker of Immune Checkpoint Inhibitors' Response and Survival in Advanced Melanoma Patients in Brazil.

Immune checkpoint blockade (ICB) agents are prominent immunotherapies for the treatment of advanced melanoma. However, they fail to promote any durable clinical benefit in a large cohort of patients. This study assessed clinical and molecular predictors of ICB response and survival in advanced melanoma. A retrospective analysis was performed on 210 patients treated with PD-1 or CTLA-4 inhibitors at Barretos Cancer Hospital, Brazil. PD-L1 expression was assessed by immunohistochemistry using formalin-fixed paraffin-embedded tumor tissues collected prior to ICB therapy. Patients were divided into responders (complete and partial response and stable disease for more than 6 months) and non-responders (stable disease for less than 6 months and progressive disease). Among them, about 82% underwent anti-PD-1 immunotherapy, and 60.5% progressed after the ICB treatment. Patients that received ICB as first-line therapy showed higher response rates than previously treated patients. Higher response rates were further associated with superficial spreading melanomas and positive PD-L1 expression (>1%). Likewise, PD-L1 positive expression and BRAF V600 mutations were associated with a higher overall survival after ICB therapy. Since ICBs are expensive therapies, evaluation of PD-L1 tumor expression in melanoma patients should be routinely assessed to select patients that are most likely to respond.

BRAFV600E Expression Is Homogenous and Associated with Nonrecurrent Disease and Better Survival in Primary Melanoma

Background: Superficial spreading melanomas (SSMs) are the most common type of melanoma and cause the majority of skin cancer deaths. More than 50% of cases harbor a mutation in the BRAF gene that activates the mitogen-activated protein kinase (MAPK) cancer signaling pathway. BRAF^V600E is the most common BRAF mutation, and it represents an important biomarker that guides treatment selection. However, the relationship between the BRAF^V600E gene expression and intratumoral protein distribution, on one side, and clinicopathological factors and patient outcomes, on the other, is not fully described. Additionally, whether MAPK cancer signaling activation in melanoma is due to increased biochemical activity of BRAF^V600E, increased mRNA levels, or both requires further investigation. Here, we addressed these questions by examining expression patterns of BRAF^V600E in primary treatment-naive melanomas and correlating them to clinicopathological factors and patient outcomes. Methods: In 166 SSM cases, we performed immunohistochemical staining to investigate the protein expression of BRAF^V600E, and we measured BRAF mRNA levels using NanoString nCounter system. Results: Ninety-seven (49%) melanomas stained positive for BRAF^V600E, with nearly 100% intratumoral homogeneity observed. Positive BRAF^V600E expression was significantly associated with nonrecurrent disease and was found to be an independent predictor of better prognosis in univariate and multivariable analyses. Furthermore, presence of tumor-infiltrating lymphocytes, sentinel lymph node biopsy negativity, and low Breslow thickness were all independent predictors of better prognosis. We observed no difference in the BRAF mRNA levels in BRAF^V600E-negative and BRAF^V600E-positive melanomas, respectively. Validation in a larger publicly available cohort confirmed that there is only a weak correlation (Spearman 0.4) between BRAF^V600E mRNA and protein levels and no differences in mRNA between BRAF^V600E mutated and non-mutated patients. Conclusion: Our findings indicated that BRAF^V600E is homogeneously present throughout the whole tumor and is associated with nonrecurrent disease and better survival in primary melanoma. We also showed that BRAF^V600E mutation does not result in higher transcriptional levels, suggesting that activation of the MAPK signaling pathway in BRAF^V600E mutated patients can be attributed to the increased biochemical activity caused by the mutation.

BRAF and NRAS prognostic values in conjunctival melanoma: analysis and literature review.

Conjunctival melanoma is a rare and aggressive tumor with a propensity for regional and distant metastases. This study aimed to analyze BRAF/NRAS markers in conjunctival melanoma and their relationship with tumor recurrences and patient prognosis. This retrospective, observational, single-center study included consecutive patients with an anatomopathological diagnosis of conjunctival melanoma, registered between January 1992 and December 2019. BRAF/NRAS mutations were analyzed using cobas®4800 kit (Roche®) in samples obtained by excisional or map biopsy. Additionally, the presence of other associated precancerous or tumor lesions was assessed. A total of 12 patients with positive histological samples for conjunctival melanoma were included (7 women, 5 men), with a mean age at diagnosis of 60 years and a mean evolution time of 6.38 ± 3.4 years. BRAF V600E mutation was observed in three biopsies (25%), similar to NRAS Q61X (25%). Recurrences occurred in all patients with positive BRAF or NRAS mutation, and five of these patients developed systemic dissemination (83.33%). Moreover, four of six patients with mutated BRAF or NRAS (66.66%) had histopathological findings of tumor or precancerous lesions. BRAF and NRAS mutations may be risk factors for recurrence and shorter survival in conjunctival melanoma, which would make these patients candidates for targeted therapies and comprehensive and individualized follow-up. All these data warrant standardized prospective studies.

BRAF Immunohistochemical Studies of Pediatric Conjunctival Lesions.

The purpose of this study was to analyze the prevalence of an activating mutation in the B-Raf proto-oncogene (BRAF) V600E immunoreactivity in pediatric conjunctival lesions. This retrospective case-control study included 32 pediatric patients who underwent surgical excision of conjunctival lesions between Jan 2019 and May 2022. The collected data included demographic data, clinical features, and histopathologic characteristics of the lesion, including BRAF V600E positivity. The Student t test and the Fisher exact test were used to determine the significance of the associations between clinical variables and BRAF positivity. BRAF immunoreactivity was positive in 11/32 lesions (34%). Age at diagnosis did not correlate with BRAF positivity, with a mean age at diagnosis of 131.7 months for patients with BRAF+ lesions and 134.7 months for those with BRAF- lesions ( P > 0.1). No clinical or pathological features were found to be significantly correlated with BRAF positivity, although there was a trend toward BRAF positivity in the presence of cysts ( P = 0.072). BRAF reactivity was present in approximately one-third of pediatric conjunctival nevi but does not correlate significantly with unique clinical or histopathological features.

PSUN378 A Turducken Phenomenon: A Case of Papillary Thyroid Carcinoma Arising Within Struma Ovarii Associated With a Large Mucinous Cystadenoma

Abstract Introduction Struma Ovarii (SO) is one of the types of mature teratoma accounting for up to 3% of all ovarian tumors, with predominant thyroid tissue (&amp;gt;50%). Most cases are reported in middle-aged women. We are presenting a case of asymptomatic papillary thyroid cancer (PTC) presented in SO that was incidentally found and treated successfully Case presentation A 72-year-old Hispanic female with a history of hysterectomy, tobacco smoking was found to have a suspicious lung nodule on screening with CT scan of Chest. A subsequent PET/CT Scan revealed incidental findings of left adnexal lesion of 12×12 cm with no FDG uptake and had a minimal uptake in lung nodule favoring a hamartoma. At the gynecology clinic, patient denied having vaginal bleeding, bowel dysfunction, abdominal pain or weight loss. She did report urinary incontinence. Pelvic exam demonstrated a mobile left adnexal mass without tenderness. MRI of Pelvis revealed a 15 cm multi-cystic, left ovarian mass compressing the urinary bladder without any lymphadenopathy. Tumor markers of CEA and CA-125 were normal. The patient underwent bilateral salpingo-oophorectomy with extensive adhesolysis. Entire ovarian mass was removed intact. Surgical Pathology revealed a 1.2 cm Unifocal PTC arising in 3 cm SO associated with mucinous cystadenoma without lympho-vascular invasion and extra-ovarian extension. No malignant cells were identified in peritoneal washing. This was staged according to AJCC 8th edition as pT1aNxMna. Immunostaining of TTF-1 and TG were positive, which additionally supported above diagnosis. Mutational testing of BRAF, K-RAS and N-RAS were negative. Post-operatively, at the Endocrine clinic, her TSH and Free T4 were normal. No nodules were detected on the thyroid ultrasound. She was deemed low risk for recurrence and no further treatment was advised except serial monitoring of Thyroglobulin levels and goal TSH &amp;lt; 2.5 mIU/L. Discussion In general, SO can be diagnosed only on a histopathological specimen and no specific radiological or biomarkers are available. Most patients are euthyroid and remain asymptomatic like our patient. Thyrotoxicosis occurs in only 5–15% of patients. SO is mostly benign. Its malignant transformation occurs in only 5% of all cases. The most widespread malignant forms of SO are papillary and follicular carcinomas. There are no well-established guidelines for optimal management of malignant SO. After undergoing oophorectomy, the decision to perform a prophylactic thyroidectomy and administration of 131I-Radioiodine is typically reserved for presence of metastatic disease or high risk of recurrence (&amp;gt;4 cm tumor size, gross extra-ovarian extension, BRAF positivity or histology other than papillary type). Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.

383P Treatment outcomes with BRAF inhibitors with or without MEK inhibitors in advanced non-small cell lung cancer with positive BRAF mutation: A systematic review

BRAF mutation is reported in about 1-5% cases of Non-small cell lung cancer (NSCLC). Although multiple phase II and retrospective studies have shown the effectiveness of single agent BRAF inhibition and combination BRAF/MEK inhibition in pre-treated and untreated patient populations; there is no phase III evidence. In this systematic review, we aimed to summarize the evidence so far in this setting.

Relationship Between The BRAF V600E And Tumor Size, Lymph Node, And Distant Metastasis In Papillary Thyroid Carcinoma

Aim – This study aimed to analyze the association between B-Raf proto-oncogene, serine/threonine kinase (BRAF) V600E and tumor size, lymph node, and distant metastasis (TNM) status on patients with papillary thyroid carcinoma. Material and Methods – This research is a cross-sectional study. A total of 40 samples were papillary thyroid carcinoma tissue paraffin blocks from thyroidectomy surgery at State General Hospital (RSUP) Dr. Kariadi Semarang. Assessment of BRAF V600E mutation protein expression through immunohistochemical methods using antibody BRAF V600E was conducted. Results – The mean age of patients with papillary thyroid carcinoma with a positive BRAF V600E mutation was 49 years. The highest incidence was 71.4% in women. A significant difference between BRAF V600E and tumor size (p=0.03) was observed with as many as 53.2% more cases at size &gt; 4 cm. A significant difference in the expression of BRAF V600E with enlargement of the lymph node (p=0.011) by 60.7% was observed compared to those without enlarged lymph nodes. On the other hand, no significant relationship between BRAF V600E expression and distant metastasis (p=0.652) was observed. The prevalence ratio in the positive BRAF V600E case at tumor size is more than 4 cm, and enlargement of lymph is 9.533 and 7.727. Conclusion – There is a significant relationship between BRAF V600E expression and tumor size and enlarged lymph nodes, while there is no significant relationship between BRAF V600E expression and distant metastases.

MLH1, BRAF and p53 - searching for significant markers to predict evolution towards adenocarcinoma in colonic sessile serrated lesions.

Background and Aim: Colonic serrated lesions are premalignant lesions, using an alternative malignization pathway, including multiple genetic and epigenetic alterations, as: mismatch repair deficiency due to MutL homolog 1 (MLH1) promoter methylation, tumor protein p53 (TP53) mutations, activating mutations of v-Raf murine sarcoma viral oncogene homolog B (BRAF) and Kirsten rat sarcoma viral oncogene homolog (KRAS). Our study aims to evaluate MLH1, BRAF and p53 immunohistochemical (IHC) status in sessile serrated lesions (SSLs), with and without dysplasia. Materials and Methods: This is a retrospective case-control study including 20 SSLs with dysplasia and 20 SSLs without dysplasia (matching sex and age). IHC expression of MLH1, BRAF and p53 was evaluated as the percent of nuclear loss of MLH1, cytoplasmic positivity of BRAF and nuclear positivity of p53. Data concerning age, sex, localization of the lesion, dysplasia and IHC results were statistically processed using Microsoft Excel. Results: We had very polymorphous patterns of IHC expression for BRAF, MLH1 and p53, especially in the dysplastic group. Thus, two patients were BRAF+/MLH1-/p53+, three were BRAF+/MLH1-/p53-, one was BRAF+/MLH1+/p53- and six were BRAF+/MLH1+/p53+. Dysplastic lesions without BRAF mutation exhibited the following phenotype: one case BRAF-/MLH1-/p53+, four BRAF-/MLH1-/p53- and three BRAF-/MLH1+/p53+. In the control group (SSLs without dysplasia), there was a more homogenous distribution of cases: eight cases BRAF+/MLH1+/p53-, seven BRAF-/MLH1+/p53-, one BRAF-/MLH1-/p53+, two BRAF-/MLH1-/p53- and two BRAF-/MLH1+/p53+. Conclusions: There are more routes on the serrated pathway, with different mutations and time of acquisition of each genetic or epigenetic lesion with the same morphological result. These lesions should be stratified according to their risk to poor outcome and their need to further surveillance.