BRAF Mutation Testing Research Articles

Patients with radioiodine-refractory differentiated thyroid cancer (RAI-R DTC) with BRAF V600E and/or K601E mutation status: A real-world view of effectiveness of lenvatinib monotherapy.

6098 Background: Lenvatinib was approved for the treatment of patients RAI-R DTC in the United States (US) in 2015, and the treatment landscape has evolved with agents targeting specific driver mutations. We assessed real-world clinical effectiveness of first line therapy with lenvatinib in patients with BRAF-mutated tumors, wild-type (WT) tumors, and patients who have not been tested for BRAF mutations (BRAF untested tumors). Methods: A retrospective chart review of RAI-R DTC patients in the US who initiated first-line lenvatinib monotherapy between February 13, 2015, and September 30, 2020. Data, including a boosted cohort of patients with BRAF-mutated tumors collected in late 2023, were abstracted from patients’ electronic health records and were de-identified. Descriptive analyses were conducted in patient cohorts with BRAF V600E and/or K601E mutated tumors, wild-type (WT) tumors, and BRAF untested tumors. Best response in first-line therapy was captured, real-world progression-free survival (rwPFS) and real-world overall survival (rwOS) were assessed using Kaplan-Meier methods. Results: Of the 361 patients reviewed, 185 had records showing BRAF mutational status testing. 89 had BRAF V600E and/or K601E mutated tumors, 96 had WT tumors. 176 patients did not have BRAF mutational assessment. Of all subjects, 73.7% were White/Caucasian, 15.2% were African American, and 16.8% were Hispanic/Latino; 27.1% had ECOG performance status ≥2. The median follow-up times for each cohort were 30.0, 18.7 and 18.0 months, showing the longer follow up period for the BRAF-mutated cohort boost. Kaplan-Meier estimation for lenvatinib treatment discontinuation for the three cohorts at 24-months were as shown in the table below. Provider-reported overall response rate (complete or partial response) was 76.4%, 75.0% and 69.3% respectively. The estimated 24-month rwPFS rates (95% CI) were 74.1% (62.2%-82.8%), 61.7% (49.6%-71.8%), and 69.8% (60.9%-77.0%) respectively. Median rwOS was not reached for patients with BRAF-mutated and WT tumors, median OS was 54.2 months for BRAF untested tumors. Estimated rwOS rates at 12- and 48-months were 93.2% (85.4%-96.9%) and 83.9% (73.3%-90.3%) in BRAF-mutated patients, 90.6% (82.8%-95.0%) and 68.5% (53.4%-79.6%) in WT patients, and 90.2% (84.7%-93.8%) and 72.5% (61.6%-80.7%) in BRAF untested patients respectively. Conclusions: In this US real-world experience, the effectiveness of lenvatinib is consistent across a diverse cohort of RAI-R DTC patients with BRAF-mutated, WT, and BRAF untested tumors. This has implications for the first-line use of lenvatinib in BRAF mutated patients. [Table: see text]

Survival of Patients With Primary Cutaneous Melanoma (Stages 0-IIА and IIB-IIC), Depending on the Presence of the <i>BRAF</i> 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.

Correlation between genetic alterations and clinicopathological features of papillary thyroid carcinomas.

To investigate the correlations between multigene alterations and clinicopathological features in papillary thyroid carcinoma (PTC) samples. In this retrospective study, 111 cytological specimens of thyroid nodules, including 74 PTC samples and 37 benign samples, were analyzed using a 22-gene mutation assay employing next-generation sequencing. Clinicopathological information was retrospectively collected and analyzed. Gene alterations were associated with a higher rate of lymph node metastasis (LNM) and thyroid capsular invasion, a lower rate of coexisting Hashimoto's thyroiditis, the classical PTC subtype, and younger age (<45 years). Among the 22 genes tested, the BRAF mutation rates showed a significant difference between the PTC and benign groups. In the subgroup analysis, younger age (odds ratio = 12.512, 95% confidence interval: 3.126-50.087) was an independent risk factor for LNM. In further analyses, BRAF mutation was significantly associated with LNM in the older subgroup (age ≥ 45 years), suggesting that the BRAF mutation test has greater value for determining PTC prognosis in the older age group. Our findings will provide a more comprehensive understanding of the relationship between gene mutations and PTC and may contribute to improved PTC management.

BRAF V600E Mutation in Malignant Melanoma-A Romanian Research Experience.

Background and Objectives: The most common mutation in malignant melanoma (MM) is the single-point mutation of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) oncogene. Our study aims to evaluate BRAF V600E mutation, highlighting its frequency differences in primary versus metastatic MM. Materials and Methods: The study group comprised 133 patients diagnosed with MM in several county hospitals of the north-eastern region of Romania who have been assigned for investigation into BRAF V600E mutation in the private medical system. The material consisted of archived formalin-fixed paraffin-embedded (FFPE) blocks. BRAF V600E mutation was identified using the fully automated IdyllaTM BRAF mutation test system. Results: Out of the total of 133 cases, 78 cases were primary tumors, while 55 cases were metastatic MMs. Genetic analysis revealed the presence of BRAF V600E mutation in 66 cases (49.62%) and the wild-type genotype in 67 cases (50.37%). We found a statistically significant difference of the mutation frequency according to age (p = 0.0072). The mutated genotype was found in 45 cases out of 78 primary MMs (57.69%) and in 21 cases out of 55 secondary MMs (38.18%), with a statistically significant difference in favor of primary tumors (p = 0.0413). The correlations between the histopathological types, Clark's level, Breslow index, ulceration, and lymphovascular invasion, respectively, and the mutated genotype were not statistically significant. BRAF V600E mutation was identified in 15 out of 40 secondary tumors with lymph node location (37.5%) and in 6 out of 15 secondary tumors with another location (40%) without statistically significant differences between the mutation frequency and the location of the secondary tumors. Conclusions: Our results support MM high genetic heterogeneity, pointing out the relationship between BRAF V600E mutation and several clinicopathological characteristics, in primary and metastatic MMs, stressing the importance of BRAF testing implementation in Romania.

Metastatic papillary thyroid carcinoma in pleural effusion: a case report and review of the literature

IntroductionPapillary thyroid carcinoma accounts for the most common type of thyroid cancer of well-differentiated type. Papillary thyroid carcinoma is featured by biologically low-grade and less aggressive tumors with a survival rate of 10 years in most of the diagnosed cases. Papillary thyroid carcinoma can be presented with the involvement of cervical lymph nodes in about 50% of the patients, yet distant spread is very uncommon.Case presentationHerein, we discuss a Saudi male patient in his early 50s with a history of papillary thyroid carcinoma who presented to the emergency department complaining of shortness of breath and a radiological finding of hydrothorax. Cytologic examination together with immune-histochemical staining and molecular studies of pleural effusion aspiration concluded the definitive diagnosis of metastatic papillary thyroid carcinoma in the pleural space.ConclusionsPapillary thyroid carcinoma seldom causes metastatic niches in the pleural space; this is a rare clinical presentation, nevertheless, a differential diagnosis of thyroid metastasis needs to be excluded. A definitive diagnosis of metastatic papillary thyroid carcinoma can be made using clinical presentation, cytologic examination, immunohistochemical investigation, and molecular testing. The most common mutation found in papillary thyroid carcinoma cases is the V600E mutation found in the BRAF gene, yet these patients have a relatively low probability of cancer recurrence. Patients with papillary thyroid carcinoma who have the BRAF mutation frequently experience metastases and relapses of the disease after the cancer has progressed aggressively. To help with therapy planning and the introduction of BRAF inhibitors, genetic testing for BRAF mutation may therefore prove to be a useful tool, especially in cases of aggressive subtypes of TC.

Assessing the Impact of Melanin Content on the Reliability of the Idylla™ BRAF Mutation Test

Aims: This study aims to investigate the potential influence of melanin content on the performance of the Idylla™ BRAF Mutation Test. Specifically, we assess whether melanin levels in samples impact the test’s reliability, thereby validating its clinical utility in accelerating melanoma diagnosis and potentially improving patient prognosis. Methods: We conducted a retrospective analysis of 98 confirmed melanoma samples collected between February 2020 and November 2020. Formalin-fixed paraffin-embedded (FFPE) slides were evaluated by two independent observers using light microscopy to categorise samples into three groups based on melanin content (no, low, or high) following a standardised system. The samples underwent the Idylla™ BRAF Mutation Test and were compared with results obtained from next-generation sequencing (NGS). Results: Quantification cycle (Cq) values were utilised to assess for interference from melanin levels on the Idylla™ BRAF Mutation Test results. Statistical analyses revealed no significant differences in Cq values based on melanin content categories. Furthermore, analysis of polymerase chain reaction PCR curves did not indicate any notable influence of melanin. Discordant results with NGS are discussed. Conclusions: The study demonstrates that melanin content in samples does not significantly affect the performance of the Idylla™ BRAF Mutation Test. These results provide robust evidence supporting the confident application of the test in clinical settings, even for samples with high melanin content. The ability to obtain rapid on-site results holds promising potential in guiding timely and appropriate treatment decisions, thereby contributing to improved patient prognosis. What is already known on this topic—Prior research conducted by Petty et al. (2020) including 23 melanoma samples suggested that melanin does not significantly interfere with the Idylla™ BRAF Mutation Test by stating they were concordant with reference laboratory testing. What this study adds—This current study builds upon prior research with a larger sample size of 98. In addition to examining concordance between the Idylla™ BRAF Mutation Test and next generation sequencing, this study examines PCR curves and effect on Cq values, providing more robust evidence that melanin content in FFPE samples does not have a significant impact on the accuracy of the Idylla™ BRAF Mutation Test. How this study might affect research, practice or policy—The additional evidence base provided by this study is valuable for researchers, clinicians, and policymakers, as it supports the integration of the Idylla™ BRAF Mutation Test as a rapid and accurate method for detecting these mutations in melanoma patients.

Implementing a BRAF biomarker electronic clinical quality measure in CancerLinQ.

418 Background: Achieving the benefits of precision oncology is dependent on timely and appropriate biomarker testing. ASCO received funding from the Gordon &amp; Betty Moore Foundation’s Diagnostic Excellence Initiative to develop and test a biomarker electronic Clinical Quality Measure (eCQM) in colorectal cancer for implementation in SmartLinQ, CancerLinQ’s quality platform. Methods: Working collaboratively with a Technical Expert Panel (TEP), ASCO staff successfully developed an eCQM, BRAF Mutational Analysis Results Received for Patients Treated for Metastatic Colorectal Cancer. CancerLinQ tested the implementation of three versions of the measure's technical specifications against data from 61 organizations and multiple electronic health record (EHR) systems. We analyzed the availability of required data elements in native and curated data, and variability and frequency of BRAF mutation testing documentation. The measure was also tested for validity and reliability among volunteer oncology practices. Results: Implementation efforts revealed that BRAF information is infrequently found in structured data fields and often lacks specificity for the specific variant tested. Ultimately, implementation of the measure in CancerLinQ was infeasible due to a lack of BRAF testing data and variant specificity across its active organizations. Reliability testing among oncology practices uncovered a lack of substantial performance gap with an average measure score of 87.4, 95% CI [86.1, 88.8], making the measure unsuitable for Consensus-Based Entity (CBE) endorsement or use in federal reporting programs. Conclusions: While ASCO’s implementation efforts yielded clear benefits, including identification of future CancerLinQ platform enhancements, gaps in the capture of BRAF testing data and inconsistent documentation of BRAF variants across EHR systems prevented successful implementation of the eCQM at this time. These findings underscore the current difficulty in ascertaining the specificity of key molecular variants in structured EHR data alone without human curation or access to unstructured data, as well as an ongoing need for measure stakeholders to advance eCQM standards necessary for supporting future eCQM deployment.

BRAF testing modalities in histiocytic disorders: Comparative analysis and proposed testing algorithm.

Understanding of histiocytic disorders has been revolutionized by demonstration of mitogen-activated protein kinase (MAPK) pathway mutations, most commonly BRAFV600E. The optimal testing strategy to assess BRAFV600E is unknown. We aimed to compare performance of testing modalities, to propose a framework for evaluation of BRAFV600E mutation status in histiocytic disorders. We retrospectively reviewed patients with histiocytic disorders and BRAF mutation testing on a lesional tissue specimen. In 120 patients, BRAF assessment included immunohistochemistry (IHC) in 97 (80.2%), polymerase chain reaction (PCR) in 35 (28.9%), and next-generation sequencing (NGS) in 62 (51.2%). Forty-five underwent both NGS and IHC. With NGS as the gold standard, the sensitivity and specificity of IHC were 82.4% and 96.4%. Three false negatives were observed in biopsy specimens with low BRAFV600E variant allele frequency or decalcified tissue. One false-positive IHC was observed in a lung biopsy specimen, likely due to antibody cross-reactivity with respiratory cilia. Among 14 with successful NGS and PCR, a single discordance was observed. Two PCR-to-IHC discrepancies were observed, including one other false-positive IHC. Immunohistochemistry was highly specific for detection of BRAFV600E. Main caveats were false negatives and lack of detection of non-BRAFV600E mutations. We propose the use of IHC as initial screening in general practice with reflex molecular testing if negative.

BRAF V600E Mutation of Non-Small Cell Lung Cancer in Korean Patients.

Background and Objectives: BRAF mutational status in resected non-small cell lung cancer (NSCLC) in the Korean population is poorly understood. We explored BRAF (particularly BRAF V600E) mutational status among Korean patients with NSCLC. Materials and Methods: This study included 378 patients with resected primary NSCLC who were enrolled from January 2015 to December 2017. The authors obtained formalin-fixed paraffin-embedded (FFPE) tissue blocks and performed peptide nucleic acid (PNA)-clamping polymerase chain reaction (PCR) for detecting BRAF V600, real-time PCR for detecting BRAF V600E, and immunohistochemical analyses using the mutation-specific Ventana VE1 monoclonal antibody. For positive cases in any methods mentioned above, direct Sanger sequencing was additionally performed. Results: The PNA-clamping method revealed the BRAF V600 mutation in 5 (1.3%) of the 378 patients. Among these five patients, real-time PCR, direct Sanger sequencing detected BRAF V600E mutations in three (0.8%) patients. Thus, two cases showed differences in their PNA-clamping and the others. Direct Sanger sequencing of PNA-clamping PCR product was performed for two cases showing negative results on direct Sanger sequencing; both contained BRAF mutations other than V600E. All patients harboring BRAF mutations had adenocarcinomas, and all patients with V600E mutation exhibited minor micropapillary components. Conclusions: Despite the low incidence of the BRAF mutation among Korean patients with NSCLC, lung adenocarcinoma patients with micropapillary components should be prioritized in terms of BRAF mutation testing. Immunohistochemical staining using Ventana VE1 antibody may serve as a screening examination for BRAF V600E.

Clinicopathological Profile of a Cohort of Patients With Malignant Melanoma in the United Kingdom.

Introduction Malignant melanoma (MM) is potentially a fatal type of skin cancer and a major health concern for the Caucasian population. It is a heterogeneous disease with a wide spectrum of manifestations. Therefore, in this study, we evaluated the clinicopathological characteristics of MM. Methods We retrospectively studied the clinicopathological characteristics of MM in 167 biopsy-proven cases of MM reported between January 2020 and December 2021 at Kings Mill Hospital, Sutton-in-Ashfield, United Kingdom. Clinical data such as the age, sex, and anatomical site of the lesion were obtained from the clinical referral forms. Biopsies of the lesions were performed, and the specimens collected were sent to the laboratory for histopathological study and v-raf murine sarcoma viral oncogene homolog B1 (BRAF) mutation evaluation. Formalin-fixed paraffin-embedded blocks (FFPE) were prepared, sectioned, and stained with hematoxylin and eosin for histological examination. Results A total of 167 cases of MM were included in the study. The age range was 23-96 years, with the median age at diagnosis found to be 66 years; males were more commonly affected (52.1%). The median Breslow thickness was 1.20 mm. The median mitotic activity was 1.0/mm2. The lower limb was the most common site of involvement (27.5%), followed by the thorax (25.1%). The most common histological subtype was superficial spreading melanoma (SSM) (77.8%), followed by nodular melanoma (14.4%). The in situ component was present in 95.8% of cases; a majority (92.2%) of the cases showed vertical growth phase, 71.9% of cases were at Clark's level IV of invasion, regression was noted in 70.7% of cases, ulceration was present in 21.6% of cases, and microsatellites were present in 3% of cases. Perineural invasion was present in 3% of cases, and lymphovascular invasion (LVI) was present in 4.2% of cases. BRAF mutation testing was performed on 36 cases, out of which 20 cases (55.6%) showed BRAF mutation. Acral lentiginous melanoma and nodular melanoma were most likely to show ulceration (66.7% and 37.5%, respectively). SSM and lentigo maligna melanoma were more likely to be associated with regression. Conclusion The study demonstrated that MM is prevalent among the elderly population with male predominance; SSM was found to be the most common subtype. The study further demonstrated various clinicopathological features of MM and its association with histological subtypes.

E029 Erdheim-Chester disease: a rare multisystem disorder

Abstract Background/Aims Erdheim-Chester disease is a rare non-Langerhans cell histiocytosis with multiorgan involvement. Otherwise known as polyostotic sclerosing histiocytosis it is characterised by proliferation and infiltration of lipid laden macrophages into bone marrow. Extraskeletal involvement is commonly seen involving heart, CNS, skin, lung, kidney, and retroperitoneum resulting in a variety of presenting features. Methods Case: 75-year-old male referred to rheumatology connective tissue disease clinic by respiratory team with dyspnoea and unintentional weight loss of 20kg in one year. CT had shown pleural effusions and interstitial markings in mid zones felt to be due to cardiac failure. PMH - IHD, CABG. Mildly elevated dsDNA of 10. He denied cough, sputum or haemoptysis. No mouth ulceration, alopecia, sicca symptoms, Raynaud's, rashes, fevers, myalgia, or joint swelling. No family history of rheumatic disease. On examination reduced air entry to lung bases, no synovitis, no nail bed changes, no lymphadenopathy. Results Further investigations showed persistent mildly elevated dsDNA, crithidia negative, negative ANA on HEp2, Hb 136, WCC 13.8, PLT 329, complement levels normal, Igs normal, IgG4 normal, NTproBNP raised 3196, ESR 27, CRP 28. Further CT CAP - bilateral pleural effusions, thickened enhancement of pleura bilaterally without focal mass, increased interstitial markings lung mid zones, significant thick pericardial enhancement and pericardial effusion, thickening around distal oesophagus and a rind of inflammatory thickening around distal thoracic aorta. Transthoracic echocardiogram - small pericardial effusion without haemodynamic compromise, normal left and right ventricular function. NM whole body - marked increased uptake in diametaphyseal regions of tibial bones and distal aspect of femora. MRI femurs - significant symmetrical abnormality in distal femoral shaft and metaphyseal region of both femora, endosteitis with extensive linear and patchy reduction T1 signal intensity and increase in STIR intensity within medullary cavity of distal femur. CT guided biopsy of distal femur identified foamy histiocytic infiltration with fibrosis. BRAF mutation testing of plasma showed strong positive result confirming molecular diagnosis of Erdheim-Chester disease. Cardiac MRI had been requested and MRI of brain was normal. He was treated initially with 40mg prednisolone, weaned to 15mg, and weekly PEG interferon with improvement in dyspnoea and weight loss. However, he deteriorated slowly over the next year and died of cardiac failure. Conclusion Histiocytic disorders such as Erdheim-Chester disease do rarely present to rheumatology given multisystem involvement and diagnostic uncertainty. This patient had skeletal, cardiac, lung, and gastrointestinal involvement resulting in his dyspnoea and weight loss. Initial treatment involves corticosteroid and interferon. Approximately 50% of patients have BRAF mutation and may respond to vemurafenib therapy. Our patient unfortunately deteriorated prior to being considered for this treatment. Prognosis is poor with a 3-year survival of 50%. Disclosure G. Starritt: None. D. McCormick: None.

Addressing the unmet needs of patients with BRAF-mutated melanoma in Latin America: Expert perspective.

Melanoma represents an increasing public health burden with extensive unmet needs in Latin America (LA). A mutation in the BRAF gene is present in approximately 50% of all melanomas in White populations and is a target of precision medicine, with the potential to dramatically improve patient outcomes. Thus, increased access to BRAF testing and therapy is LA must be explored. At a multi-day conference, a panel of Latin American experts in oncology and dermatology were provided with questions to address the barriers limiting access to testing for BRAF mutation in patients with melanoma in LA, who may be eligible for targeted therapy to improve their prognosis. During the conference, responses were discussed and edited until a consensus on addressing the barriers was achieved. Identified challenges included ignorance of BRAF-status implications, limited human and infrastructural resources, affordability and reimbursement, fragmented care delivery, pitfalls in the sample journey, and lack of local data. Despite the clear benefits of targeted therapies for BRAF-mutated melanoma in other regions, there is no clear path to prepare LA for a sustainable personalized medicine approach to this disease. Due to melanoma's time-sensitive nature, LA must aim to provide early access to BRAF testing and consider mutational status within treatment decision making. To this end, recommendations are provided and include establishing multidisciplinary teams and melanoma referral centers and improving access to diagnosis and treatment.

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

BRAF mutation occurs in 5%-10% of metastatic colorectal cancers (mCRCs). Patients with BRAF mutant mCRC exhibit a specific metastatic pattern and poor prognosis. Survival outcomes are heterogeneous in cases of mCRC with a BRAF mutation. The optimal first-line therapy is still controversial. We retrospectively reviewed the medical records of patients with mCRC between June 2010 and December 2021. Clinicopathologic characteristics, treatment and BRAF mutation testing results were collected. Patients with a BRAF mutation were included. Kaplan-Meier methods and log-rank tests were used to analyze and compare survival. Cox proportional hazards regression was used to establish the predictive nomogram model. Of the 4475 mCRC, 261 have a BRAF mutation, including 240 V600E and 21 non-V600E mutants. The median overall survival (OS) was 18.2months in the BRAF V600E mutant group versus 38.0months in the non-V600E mutant group (p=0.022). ECOG score, tumor differentiation, liver metastasis, bone metastasis and primary tumor resection were independent prognostic factors for the OS of BRAF V600E mutant mCRC. A nomogram model was established using these factors. The median OS was 39.3m, 18.2m and 10.7m for the low-risk, intermediate-risk and high-risk groups defined by this model, respectively (p < 0.0001). Patients who received first-line triplet chemotherapy ± bevacizumab had comparable progression free survival (PFS) and OS compared with those treated with doublets ± bevacizumab. BRAF V600E mutant mCRCs exhibit unfavorable and heterogeneous prognosis. The first-line intensive chemotherapy did not confer a marked impact on the PFS and OS.

Reflex testing for RAS and BRAF mutations in metastatic colorectal cancer: A single Canadian academic oncology center experience.

86 Background: Patients with left-sided metastatic colorectal cancer (mCRC) without mutations in RAS or BRAF V600E are eligible to a combination treatment of an anti-EGFR monoclonal antibody in association with chemotherapy. This combination is associated with a survival benefit and is recommended by oncology guidelines as first line therapy for RAS/BRAF wild type left-sided mCRC patients. The CHUM (University of Montreal Hospital Center) has implemented reflex testing of RAS/BRAF mutations for mCRC since October 22nd 2019, and was one of the only hospitals in Canada to do so. With this study, we want to demonstrate that reflex testing of these mutations improves the quality of care received by patients. Methods: In this retrospective study, we reviewed pathological and clinical data of 101 patients with newly diagnosed mCRC that had their pathological diagnosis done at the CHUM. Patients diagnosed between July 1st 2017 and October 21st 2019, before implementation of reflex testing, (“Before reflex testing” group, n = 62 patients) were compared to patients diagnosed between October 22nd 2019 and December 31st 2021 (“After reflex testing” group, n = 39 patients). Results: The average delay between the mCRC biopsy and the result of the RAS/BRAF mutations was reduced to 25 days (CI95% 22.6 – 28.1) in the “After reflex testing” group, compared to 154 days (CI95% 111.2 – 202.5) in the “Before reflex testing” group. Respectively 66% (41/62) of patients in the “Before reflex testing” group and 69% (27/39) of patients in the “After reflex testing” received a systemic treatment. At initiation of systemic therapy, results of RAS/ BRAF mutations were available for 85% (35/41) of patients in the “After reflex testing” group, versus only 17% (7/41) of patients in the “Before reflex testing” group. Among patients eligible for an anti-EGFR monoclonal antibody and who received it, 100% of them (6/6) received it in the first line setting in the “After reflex testing” group, compared to 33% (3/9) in the “Before reflex testing” group. Conclusions: Our study shows that with reflex testing of RAS/ BRAF mutations, oncologists have quicker access to all relevant information to make the best treatment decision for their patients. It allows eligible patients to receive an anti-EGFR therapy in the first line setting, as recommended by oncology guidelines.

Rates and outcomes of testing for lynch syndrome in a national colorectal cancer screening programme

BackgroundLynch Syndrome (LS), the most common cause of hereditary colorectal cancer (CRC), is characterised by pathogenic variants in mismatch repair (MMR) genes. Universal testing of all CRCs for LS can increase detection. Rates and outcomes of testing in Ireland’s national CRC screening programme have not been examined previously. MethodsCRCs diagnosed at two screening sites between 2015 and 2020 were identified. Patient records were used to determine if CRCs had been tested for MMR deficiency and if detected, what downstream testing to rule out LS or genetic testing to confirm LS was undertaken. ResultsOver five years, 206 CRCs were diagnosed. Testing for LS was carried out for 100% of CRCs at site A and 69% of CRCs at site B. Of CRCs tested for LS, 14 (8%) were MMR deficient. After downstream testing for BRAF mutation or hypermethylation of MLH1, three CRCs were identified as potentially LS-related. Of these two individuals declined genetic testing and one was lost to follow-up. ConclusionsBy 2020 both sites had implemented universal testing of all CRCs for LS. A small number of individuals were identified as being eligible for genetic testing for LS, however those offered declined testing and one individual was lost to follow up. This highlights the importance of universal testing and the need for referral pathways to ensure all appropriate individuals are referred onwards to genetic services.

Significance of incidental focal fluorine-18 fluorodeoxyglucose uptake in colon/rectum, thyroid, and prostate: With a brief literature review.

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT), a functional imaging method, is usually performed on the entire torso, and regions of unexpected suspicious focal hypermetabolism are not infrequently observed. Among the regions, colon, thyroid, and prostate were found to be the common organs in a recent umbrella review. Some studies reported that a high rate of malignancy was shown in incidentally identified focal hypermetabolic regions and suggested that further examinations should not be ignored. To investigate the malignancy rate of incidental focal FDG uptake, useful PET parameters and their cutoffs in discrimination between malignant and benign lesions. Retrospectively, the final reports of 16510 F-18 FDG PET/CT scans performed at our hospital between January 2016 and March 2022 were reviewed to identify incidentally observed FDG uptake in the colon/rectum, thyroid, and prostate. The scans of patients with current or prior malignancies at each corresponding location, without the final reports of histopathology or colonoscopy (for colon and rectum) for the corresponding hypermetabolic regions, or with diffuse (not focal) hypermetabolism were excluded. Finally, 88 regions of focal colorectal hypermetabolism in 85 patients (48 men and 37 women with mean age 67.0 ± 13.4 years and 63.4 ± 15.8 years, respectively), 48 focal thyroid uptakes in 48 patients (12 men and 36 women with mean age 62.2 ± 13.1 years and 60.8 ± 12.4 years, respectively), and 39 focal prostate uptakes in 39 patients (mean age 71.8 ± 7.5 years) were eligible for this study. For those unexpected focal hypermetabolic regions, rates of malignancy were calculated, PET parameters, such as standardized uptake value (SUV), capable of distinguishing between malignant and benign lesions were investigated, and the cutoffs of those PET parameters were determined by plotting receiver operating characteristic curves. In the colon and rectum, 29.5% (26/88) were malignant and 33.0% (29/88) were premalignant lesions. Both SUVmax and SUVpeak differentiated malignant/premalignant from benign lesions, however, no parameters could distinguish malignant from premalignant lesions. Higher area under the curve was shown with SUVmax (0.752, 95%CI: 0.649-0.856, P < 0.001) and the cutoff was 7.6. In the thyroid, 60.4% (29/48) were malignant. The majority were well-differentiated thyroid cancers (89.7%, 26/29). The results of BRAF mutation tests were available for 20 of the 26 well-differentiated thyroid cancers and all 20 had the mutation. Solely SUVmax differentiated malignant from benign lesions and the cutoff was 6.9. In the prostate, 56.4% (22/39) were malignant. Only SUVmax differentiated malignant from benign lesions and the cutoff was 3.8. Overall, among the 175 focal hypermetabolic regions, 60.6% (106/175) were proven to be malignant and premalignant (in colon and rectum) lesions. Approximately 60% of the incidentally observed focal F-18 FDG uptake in the colon/rectum, thyroid, and prostate were found to be malignant. Of the several PET parameters, SUVmax was superior to others in distinguishing between malignant/premalignant and benign lesions. Based on these findings, incidental focal hypermetabolism should not be ignored and lead physicians to conduct further investigations with greater confidence.

Liquid biopsy for KRAS, NRAS and BRAF mutation testing in advanced colorectal cancer patients: the Argentinean experience.

Objective: To analyze the frequency of KRAS, NRAS and BRAF hotspot mutations in circulating tumor DNA (ctDNA) from patients with metastatic colorectal cancer (mCRC). Methods: Observational, descriptive and retrospective study in mCRC patients with available ctDNA-based genotype of KRAS, NRAS and BRAF. Results: The frequencies of plasma mutations for KRAS, NRAS and BRAF were 34% (±7), 4% (±3) and 4% (±3), respectively. Median overall survival of plasma-tested RAS/BRAF-mutated patients was 26.6months (95% CI: 14.4-not estimable [NE]), while RAS/BRAF wild-type patients did not reach the median survival during follow-up. Median progression-free survival for RAS/BRAF wild-type and RAS/BRAF-mutated patients was 12 (95% CI: 7-NE) and 4months (95% CI: 4-NE), respectively. Conclusion: Our work supports the utility of KRAS, NRAS and BRAF analysis in liquid biopsy from mCRC patients.

Tumor profiling of KRAS, BRAF, and NRAS gene mutations in patients with colorectal cancer: A Lebanese major center cohort study

BackgroundIn the era of precision medicine, treatment schemes for advanced Colorectal (CRC) disease include monoclonal antibodies which block the epidermal growth factor receptor (EGFR) implicated in tumor proliferation, invasion, migration and neovascularization. Resistance to these agents has been correlated with activating downstream mutations in KRAS, BRAF and NRAS genes, among others, leading to constitutive activation of the EGFR axis bypassing EGFR blockade. The assessment of tumor RASandBRAFmutational status has thus become standard clinical practice. While multiple investigations reported roughly mutations rates of 40% in KRAS, 7% in NRAS and 5–15 % in BRAF, numbers vary across different populations with limited data specifically from the Middle East. MethodsThis is a retrospective observational Laboratory information system (LIS) chart review of all the patients with pathologically confirmed colorectal carcinoma (CRC) or metastatic CRC who underwent KRAS, NRAS and/or BRAF mutational analysis testing at the Molecular Diagnostics Laboratory of the American University of Beirut Medical Center (AUBMC) from January 2012 to December 2018, inclusive. Data retrieved included the results of mutation testing performed for KRAS, NRAS and BRAF genes, the age, gender, and tumor location for each patient. Analysis of the mutations was performed using polymerase chain reaction (PCR) hybridization StripAssay® (ViennaLab, Vienna, Austria). Results130 (47.6%) out of 273 histologically confirmed CRC cases, had positive KRAS mutations, namely in codons 12 (82%), 13 (17%), 146 (1.5%), 117 (0.75%), or 61 (0.75%). Two patients had two concomitant mutations: 12 + 12 (different mutations) and 12 + 146. Of 203 CRC cases tested for NRAS mutations, 16 (7.8%) were found to be positive for a mutation in codon 12 (37.5%), 61 (37.5%), or 13 (12.5%). Two patients had two concomitant mutations: 12 + 13 and 59 + 61. Of 172 CRC cases tested for BRAF mutations, 2 (1.2 %) were positive for the V600E -. ConclusionThis retrospective study is the first to report the frequencies of KRAS, NRAS and BRAF gene mutations in a Lebanese CRC cohort diagnosed and managed at a tertiary care center. The frequencies of the studied somatic gene mutations were similar to previously reported cohorts in other populations however the rate of BRAF mutation was lower in this cohort than expected.

Comparison of Two Rapid Assays for the Detection of BRAF V600 Mutations in Metastatic Melanoma including Positive Sentinel Lymph Nodes

Testing for the BRAF mutation is mandatory for the management of patients with locally advanced or metastatic melanoma. Molecular analysis based on DNA sequencing remains the gold-standard method for the screening of the different BRAF mutations. These methods must be rapid, sensitive, and specific enough to allow optimal therapeutic management in daily practice and also to include patients in clinical trials. Here, we compared the Idylla BRAF Mutation Test and the anti-BRAF V600E (clone VE1) immunohistochemistry (IHC) in 90 melanoma samples, with a focus on a challenging cohort of 32 positive sentinel lymph nodes. The BRAF status was assessed with both methods independently of the percentage of tumor cells. The concordance rate was calculated excluding both non-contributory analyses and BRAF V600K/R/M mutants due to the specific V600E-IHC test design. The incidence of the BRAF V600E mutation was 33% with both BRAF Idylla and BRAF IHC. The agreement rate was 91% (72/79). Although the agreement rate was high, we suggest that the use of IHC is more suitable for rapid BRAF testing on sentinel lymph node biopsies when associated with a low percentage and scattered tumor cells, which gave a high risk of non-contributory analysis and/or false negative results with the IdyllaTM BRAF Mutation Test.

Pathologist initiated reflex BRAF mutation testing in metastatic melanoma: experience at a specialist melanoma treatment centre

Testing for BRAF mutations in metastatic melanoma is pivotal to identifying patients suitable for targeted therapy and influences treatment decisions regarding single agent versus combination immunotherapy. Knowledge of BRAF V600E immunohistochemistry (IHC) results can streamline decisions during initial oncology consultations, prior to DNA-based test results. In the absence of formal guidelines that require pathologist initiated ('reflex') BRAF mutation testing, our institution developed a local protocol to perform BRAF V600E IHC on specimens from all stage III/IV melanoma patients when the status is otherwise unknown. This study was designed to evaluate the application of this protocol in a tertiary referral pathology department. A total of 408 stage III/IV melanoma patients had tissue specimens accessioned between 1 January and 31 March in three consecutive years (from 2019 to 2021), reported by 32 individual pathologists. The BRAF mutation status was established by pathologists in 87% (352/408) of cases. When a prior BRAF mutation status was previously known, as confirmed in linked electronic records (202/408), this status had been communicated by the clinician on the pathology request form in 1% of cases (3/202). Pathologists performed BRAF V600E IHC in 153 cases (74% of cases where the status was unknown, 153/206) and testing was duplicated in 5% of cases (20/408). Reflex BRAF IHC testing was omitted in 26% of cases (53/206), often on specimens with small volume disease (cytology specimens or sentinel node biopsies) despite adequate tissue for testing. Incorporating BRAF IHC testing within routine diagnostic protocols of stage III/IV melanoma was both feasible and successful in most cases. Communication of a patient's BRAF mutation status via the pathology request form will likely improve implementation of pathologist initiated BRAF mutation testing and may result in a reduction of duplicate tests. To improve pathologist reflex testing rates, we advocate for the use of an algorithmic approach to pathologist initiated BRAF mutation testing utilising both IHC and DNA-based methodologies for stage III/IV melanoma patients.