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    Topic review

    BRAF Mutation in Cutaneous Melanoma

    Subjects: Oncology
    View times: 32
    Contributors: Ivan Litvinov , Sarah Zhou
    Submitted by: Ivan Litvinov
    (This entry belongs to Entry Collection "Skin Pathologies ")

    Definition

    In advanced melanoma, BRAF mutation testing is critical in predicting treatment response with targeted therapy (i.e., BRAF/MEK inhibitors). Certain features were identified in melanomas that harbor BRAF mutations (e.g., primary lesions located on the trunk, diagnosed in patients <50, visibly pigmented tumors and, at times, with ulceration or specific dermatoscopic features). For select advanced melanoma patients, delays in determining mutational status present a significant barrier to the prompt initiation of treatment.  This can adversely impact patient outcomes, especially in the metastatic setting due to a rapidly progressive disease. Treatment in these cases needs to start promptly by a medical oncologist. Ordering BRAF testing by preceding members of the treating team will allow medical oncologists to initiate treatment at the first visit. According to poor survival outcomes, we propose that patients with thick tumors (>4.0 mm) or >2 mm tumors with ulceration (i.e., stage ≥IIB) should potentially be considered for systemic therapy, thus justifying reflex BRAF testing.

    1. Introduction

    Melanoma incidence and mortality are continuously increasing in the United States, Canada, and other countries around the world [1][2][3][4]. Advances in our understanding of molecular pathways have led to improvements in the historically unfavorable prognosis of metastatic melanoma [5]. One of the most studied regulatory signaling pathways is the mitogen-activated protein (MAP) kinase pathway. In the early 2000s, it was discovered that many cases of metastatic melanoma exhibited inappropriate activation of this pathway through a mutated BRAF oncogene [6]. Since then, the development of targeted therapies to suppress this signaling have given BRAF-mutation status a critical role in the clinical decision making for the treatment of advanced melanoma.
    Despite the importance of the MAP kinase pathway in the treatment of melanoma, there is no consensus at which time point BRAF mutation testing should take place during the workup of melanoma. For some patients, delays in determining mutational status present a significant barrier to the prompt initiation of treatment. This can adversely impact patient outcomes, especially in the metastatic setting, where patients may have rapidly progressive disease. Treatment in these cases needs to start promptly at the time of diagnosis.

    2. BRAF Testing at the Time of Diagnosis

    2.1. Overview of Diagnosis

    The definitive diagnosis of melanoma requires histopathologic assessment of the tumor. Based on the eighth edition of the American Joint Committee on Cancer (AJCC) staging system, parameters of the primary tumor (T), lymph nodes and lymphatic drainage (N), and distant metastases (M) are used to determine the pathologic stage. Patients with primary tumors without spread are classified as stage I or II, depending on the tumor characteristics (tumor thickness and ulceration only). Tumors that have spread beyond the primary skin site as indicated by the presence of in-transit tumors, satellite tumors, or involvement of lymph nodes, but without distant metastases are classified as stage III. Patients with distant metastases are categorized as stage IV. Each stage carries a different risk of disease relapse and survival [7] (Table 1).
    Table 1. Frequently reported features of melanoma found to be associated with BRAF mutation status.
    Features/Outcomes Primary Melanoma Metastatic Melanoma
    BRAF mutation prevalence Primary melanoma: 33–47% [6] Metastatic melanoma: 41–55% [6]
      Recurrent melanoma found to have higher frequency of BRAF mutation [8] -
         Patient Features
    Age of diagnosis <50 [6][9] Younger individuals [6]
    UV exposure High estimated lifetime exposure [10] and early-life exposure [10][11] -
    Total body nevus count Patients with high number of nevi on back (>14) [10] more likely to harbor a BRAF mutation -
    Chronic sun-damaged skin Fewer signs of chronic sun damage [9], such as lentigines [11] and solar elastosis [8][10] Less chronic sun damage [6]
        Melanoma Features
    Number of primary lesions - Occult or 1 lesion [6]
    Location of primary melanoma Truncal location [6][9][7] Truncal location [6]
    Melanoma subtype Superficial spreading [9] or nodular [8] -
    Pigmentation Presence of pigmentation on pathology and as detected by patient [11] -
    Breslow thickness (of primary) BRAF mutation associated with increased tumor thickness compared to wildtype [12][13] -
    Ulceration (of primary) BRAF mutation associated with the presence of ulceration [8][7][14][15] No association [6]
    Dermoscopy features Irregular peripheral streaks [16], blue-white veil [17], and “peppering” [18] -
    Outcomes    
    Stage at presentation Presentation at a more advanced stage is associated with BRAF mutation [9][19]  
    Response to chemotherapy - No association [6]
    Response to BRAF/MEK inhibitor - Highly predictive of response to therapy [20]
    Disease-free interval (primary diagnosis to first distant metastasis) - No association [6]
    Outcome (survival) No association [6] Further investigation necessary
    Importantly, variability exists in the published guidelines directing BRAF mutation testing. The NCCN guidelines recommend BRAF testing in patients for whom targeted therapy may be an option [21]. This includes patients with stage III melanoma at high risk for recurrence or patients presenting with loco-regional recurrence or stage IV disease. The NCCN panel does not recommend BRAF testing for resected pathologic stage I or II cutaneous melanoma unless the results may be used to direct participation in clinical trials. The European Society for Medical Oncology (ESMO) mandates mutation testing for all patients with advanced disease, which includes stages III or IV (resected or unresected) [22]. Contrary to the NCCN guidelines, ESMO recommends mutation testing for high-risk pathologic stage IIC melanoma patients.
    As the landscape for treatment options expands, clear guidelines for biomarker testing ensure that high-risk patients receive the first-line treatment options for which they are eligible. As mentioned, there is currently a discrepancy between the published guidelines. In congruence with the ESMO guideline recommendation for testing, pathologic stage IIC should be recognized as high-risk melanoma, and these tumors should undergo mutation testing. This is supported by the evidence/clinical data reporting that stage IIC melanoma patients have paradoxically worse outcomes of overall survival (OS) and relapse-free survival (RFS), when compared to patients presenting at stage IIIA [23][24]. Specifically, 5-year survival rates for both stage IIB and stage IIC disease (87% and 82%, respectively) are lower than the 5-year survival rate of 93% for stage IIIA melanoma [7][23]. Although targeted or immunotherapies are not currently formally indicated in high-risk stage II patients, a number of ongoing clinical trials (e.g., MK-3475-716/KEYNOTE-716 and CheckMate76K trials) will aid to resolve the role of adjuvant therapy in pathologic stage IIB/C disease. Hence, patients with thick tumors (>4.0 mm) or >2 mm tumors with ulceration should potentially be considered for systemic therapy, thus justifying reflex BRAF testing in this higher-risk patient population.

    2.2 Methods of BRAF Mutation Testing

    Many testing options are available to detect BRAF mutations, each with unique strengths and weaknesses to be taken into consideration. The current guidelines do not provide a detailed diagnostic testing algorithm. In clinical practice, some centers use immunohistochemistry (IHC) as a preliminary screening tool to initiate treatment. Confirmatory testing can then be performed using molecular techniques. Other centers prefer the use of real-time PCR (RT-PCR) or next-generation sequencing (NGS) approaches to detect mutations over IHC. Notably, in Canada, confirmatory/validation testing can be performed within a hospital testing center using a locally accepted technology. However, in the United States, only specific platforms certified by the Food and Drug Administration (FDA) can be used to confirm BRAF mutation status. In Europe, according to the ESMO guidelines, a validated test should be used only in an accredited (certified) institute that includes appropriate quality controls [25]. A summary of the diagnostic testing modalities is provided in Table 2.
    Table 2. Summary of diagnostic testing modalities used to detect BRAF-mutated melanoma. IHC, immunohistochemistry; HRM, high-resolution melt; NGS, next-generation sequencing; RT-PCR, real-time polymerized chain reaction.
    Features IHC RT-PCR HRM Sanger Pyrosequencing NGS
    Cobas® THxID®
    Detection of mutations [26][27] VE1 antibody for V600E V600E V600E
    V600K
    Indirectly detects mutations Whole exon, detects rare mutations Optimized for V600 mutations Whole exon, detects rare mutations
    Sensitivity Up to 98.6% [28] 95% [29] >96% (V600E) >92% (V600K) [26] 99% [27] 92.5% (for V600E) [29] 90 to 100% [27][30] 99% [31]
    Specificity 97.7% [28] 98% [26] 100% [26] 100% [27] 100% [27] 95 to 100% [27][30] 100% [31]
    Limit of detection (i.e., proportion of cells that are positive) Few cells [32] 7% [27] 5% [26] 6.6% [26] 6.6% [33] 5.0% [34] 2% [27]
    Turnaround time [27] <1 day 1 day 1 day Up to 3 days 2 days Up to 5 days
    Cost [27] Low Medium Low Medium High Very high

    3. Recomendations

    The implementation of carefully developed disease-specific reflex testing criteria by a multidisciplinary team is important to avoid the futile use of valuable healthcare resources. For BRAF mutation in the context of melanoma, reflex testing criteria should include advanced disease characteristics, as these patients would benefit the most from rapid initiation of BRAF/MEK inhibitors. These features to a clinician/pathologist might include melanomas exhibiting clinical characteristics associated with BRAF mutation (Table 1), thick tumors of Breslow depth 2-4 or >4mm with or without ulceration (i.e., stages IIB and IIC, respectively) and all patients with nodal involvement (i.e., stage III) or lymphatic progression (satellitosis or in transit metastasis). While systemic therapies are not approved for patients with pathologic stage II melanoma, considering the risk of disease progression in these individuals and decreased 5 and 10-year survival rates (82% and 75%, respectively for stage IIC and 87% and 82%, respectively for stage IIB disease), knowledge of the BRAF mutational status may prove useful for selection of future therapies. Furthermore, most often if stage IIB/C melanoma recurs, this usually occurs within 2 years of surgery. Advanced knowledge of the mutation status will help initiate treatment faster for newly metastatic or recurrent disease. While many tertiary care centers and specialized melanoma programs have or are actively implementing reflex BRAF mutation testing, it is paramount to promote this change across community hospitals as well, so that patients with high risk (stage ≥IIB) melanoma can consistently arrive to their first medical oncology appointment with this information at hand to make an informed treatment decision. This maybe critically important for those patients, who present to the multidisciplinary clinic with far more advanced melanomas than implied by the microstaging features of the primary tumor. For example, patients with large infiltrating tumors of dubious resectability or tumors that involve vital structures might benefit from neoadjuvant targeted therapy to facilitate their removal. Furthermore, as noted earlier, ongoing clinical trials (MK-3475-716/KEYNOTE-716 and CheckMate76K that enroll stage IIB and IIC patients) should answer the question whether these patients might benefit from adjuvant targeted therapy. The collective agreement on worrisome signs identifiable by dermatologists, surgeons, pathologists and oncologists will enable for cost-effective reflex BRAF testing and timely management for patients.

    4. Conclusions

    Exploitation of the MAP kinase signaling pathway has led to great improvements in the prognosis of metastatic melanoma. Mutational testing of high-risk melanoma gives patients the option of personalized treatment, which has been shown to provide a greater survival benefit than historical treatment modalities. Importantly, the implementation of standardized reflex testing criteria will allow for timely initiation of these treatment options. Further research identifying optimal use of therapies and new molecular targets will continue to improve the outlook for advanced melanoma.

    The entry is from 10.3390/cancers13092282

    References

    1. Ghazawi, F.M.; Cyr, J.; Darwich, R.; Le, M.; Rahme, E.; Moreau, L.; Netchiporouk, E.; Zubarev, A.; Roshdy, O.; Glassman, S.J.; et al. Cutaneous malignant melanoma incidence and mortality trends in Canada: A comprehensive population-based study. J. Am. Acad. Dermatol. 2019, 80, 448–459.
    2. Ghazawi, F.M.; Le, M.; Lagacé, F.; Cyr, J.; AlGhazawi, N.; Zubarev, A.; Roy, S.F.; Rahme, E.; Netchiporouk, E.; Roshdy, O.; et al. Incidence, Mortality, and Spatiotemporal Distribution of Cutaneous Malignant Melanoma Cases Across Canada. J. Cutan. Med. Surg. 2019, 23, 394–412.
    3. Muntyanu, A.; Savin, E.; Ghazawi, F.M.; Alakel, A.; Zubarev, A.; Litvinov, I.V. Geographic Variations in Cutaneous Melanoma Distribution in the Russian Federation. Dermatology 2020, 236, 1–8.
    4. Ghazawi, F.M.; Le, M.; Alghazawi, N.; Rahme, E.; Moreau, L.; Netchiporouk, E.; Zubarev, A.; Roshdy, O.; Glassman, S.J.; Sasseville, D.; et al. Trends in incidence of cutaneous malignant melanoma in Canada: 1992-2010 versus 2011-2015. J. Am. Acad. Dermatol. 2019, 80, 1157–1159.
    5. Petrella, T.; Ernst, S.; Spatz, A.; Claveau, J. Canadian perspective on the clinical management of metastatic melanoma. Lung 2012, 70, 87.
    6. Long, G.V.; Menzies, A.M.; Nagrial, A.M.; Haydu, L.E.; Hamilton, A.L.; Mann, G.J.; Hughes, T.M.; Thompson, J.F.; Scolyer, R.A.; Kefford, R.F. Prognostic and Clinicopathologic Associations of Oncogenic BRAF in Metastatic Melanoma. J. Clin. Oncol. 2011, 29, 1239–1246.
    7. Gershenwald, J.E.; Scolyer, R.A.; Hess, K.R.; Sondak, V.K.; Long, G.V.; Ross, M.I.; Lazar, A.J.; Faries, M.B.; Kirkwood, J.M.; McArthur, G.A.; et al. Melanoma staging: Evidence-based changes in the American Joint Committee on Cancer eighth edition cancer staging manual. CA Cancer J. Clin. 2017, 67, 472–492.
    8. Spathis, A.; Katoulis, A.C.; Damaskou, V.; Liakou, A.I.; Kottaridi, C.; Leventakou, D.; Sgouros, D.; Mamantopoulos, A.; Rigopoulos, D.; Karakitsos, P.; et al. BRAF mutation status in primary, recurrent, and metastatic malignant melanoma and its relation to histopathological parameters. Dermatol. Pract. Concept. 2019, 9, 54–62.
    9. Kim, S.Y.; Hahn, H.J.; Lee, Y.W.; Choe, Y.B.; Ahn, K.J.; Kim, S.N. Metaanalysis of BRAF mutations and clinicopathologic characteristics in primary melanoma. J. Am. Acad. Dermatol. 2015, 72, 1036–1046.e2.
    10. Thomas, N.E.; Edmiston, S.N.; Alexander, A.; Millikan, R.C.; Groben, P.A.; Hao, H.; Tolbert, D.; Berwick, M.; Busam, K.; Begg, C.B.; et al. Number of Nevi and Early-Life Ambient UV Exposure Are Associated with BRAF-Mutant Melanoma. Cancer Epidemiol. Biomark. Prev. 2007, 16, 991–997.
    11. Liu, W.; Kelly, J.W.; Trivett, M.; Murray, W.K.; Dowling, J.P.; Wolfe, R.; Mason, G.; Magee, J.; Angel, C.; Dobrovic, A.; et al. Distinct Clinical and Pathological Features Are Associated with the BRAFT1799A(V600E) Mutation in Primary Melanoma. J. Investig. Dermatol. 2007, 127, 900–905.
    12. Ellerhorst, J.A.; Greene, V.R.; Ekmekcioglu, S.; Warneke, C.L.; Johnson, M.M.; Cooke, C.P.; Wang, L.-E.; Prieto, V.G.; Gershenwald, J.E.; Wei, Q.; et al. Clinical Correlates of NRAS and BRAF Mutations in Primary Human Melanoma. Clin. Cancer Res. 2011, 17, 229–235.
    13. García-Casado, Z.; Traves, V.; Banuls, J.; Niveiro, M.; Gimeno-Carpio, E.; Jimenez-Sanchez, A.; Moragon, M.; Onrubia, J.; Oliver, V.; Kumar, R. BRAF, NRAS and MC 1R status in a prospective series of primary cutaneous melanoma. Br. J. Dermatol. 2015, 172, 1128–1131.
    14. Anand, K.; Phung, T.L.; Bernicker, E.H.; Cagle, P.T.; Olsen, R.J.; Thomas, J.S. Clinical Utility of Reflex Ordered Testing for Molecular Biomarkers in Lung Adenocarcinoma. Clin. Lung Cancer 2020, 21, 437–442.
    15. The Society of Gynecologic Oncology of Canada. Why is Tumour Testing in Ovarian Cancer Needed in Canada? An Opinion Statement Developed by the National BRCA Collaborative. Available online: (accessed on 2 March 2021).
    16. Bombonato, C.; Ribero, S.; Pozzobon, F.; Puig-Butille, J.; Badenas, C.; Carrera, C.; Malvehy, J.; Moscarella, E.; Lallas, A.; Piana, S.; et al. Association between dermoscopic and reflectance confocal microscopy features of cutaneous melanoma with BRAF mutational status. J. Eur. Acad. Dermatol. Venereol. 2016, 31, 643–649.
    17. Armengot-Carbó, M.; Nagore, E.; García-Casado, Z.; Botella-Estrada, R. The association between dermoscopic features and BRAF mutational status in cutaneous melanoma: Significance of the blue-white veil. J. Am. Acad. Dermatol. 2018, 78, 920–926.e4.
    18. Pozzobon, F.; Puig-Butillé, J.; González-Alvarez, T.; Carrera, C.; Aguilera, P.; Alos, L.; Badenas, C.; Grichnik, J.; Malvehy, J.; Puig, S. Dermoscopic criteria associated with BRAF and NRAS mutation status in primary cutaneous melanoma. Br. J. Dermatol. 2014, 171, 754–759.
    19. Mann, G.J.; Pupo, G.M.; Campain, A.E.; Carter, C.D.; Schramm, S.-J.; Pianova, S.; Gerega, S.K.; De Silva, C.; Lai, K.; Wilmott, J.S.; et al. BRAF Mutation, NRAS Mutation, and the Absence of an Immune-Related Expressed Gene Profile Predict Poor Outcome in Patients with Stage III Melanoma. J. Investig. Dermatol. 2013, 133, 509–517.
    20. Tarhini, A.; Kudchadkar, R.R. Predictive and on-treatment monitoring biomarkers in advanced melanoma: Moving toward personalized medicine. Cancer Treat. Rev. 2018, 71, 8–18.
    21. Network, N.C.C. Cutaneous Melanoma. Available online: (accessed on 2 March 2020).
    22. Michielin, O.; Van Akkooi, A.C.J.; Ascierto, P.A.; Dummer, R.; Keilholz, U.; ESMO Guidelines Committee. Cutaneous melanoma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann. Oncol. 2019, 30, 1884–1901.
    23. Miller, R.; Walker, S.; Shui, I.; Brandtmüller, A.; Cadwell, K.; Scherrer, E. Epidemiology and survival outcomes in stages II and III cutaneous melanoma: A systematic review. Melanoma Manag. 2020, 7, 39–53.
    24. Tan, S.Y.; Najita, J.; Li, X.; Strazzulla, L.C.; Dunbar, H.; Lee, M.-Y.; Seery, V.J.; Buchbinder, E.I.; Tawa, N.E.; McDermott, D.F.; et al. Clinicopathologic features correlated with paradoxical outcomes in stage IIC versus IIIA melanoma patients. Melanoma Res. 2019, 29, 70–76.
    25. Normanno, N. BRAF in Melanoma: ESMO Biomarker Factsheet. Available online: (accessed on 23 April 2021).
    26. Cheng, L.; Lopez-Beltran, A.; Massari, F.; MacLennan, G.T.; Montironi, R. Molecular testing for BRAF mutations to inform melanoma treatment decisions: A move toward precision medicine. Mod. Pathol. 2018, 31, 24–38.
    27. Ihle, M.A.; Fassunke, J.; König, K.; Grünewald, I.; Schlaak, M.; Kreuzberg, N.; Tietze, L.; Schildhaus, H.-U.; Büttner, R.; Merkelbach-Bruse, S. Comparison of high resolution melting analysis, pyrosequencing, next generation sequencing and immunohistochemistry to conventional Sanger sequencing for the detection of p.V600E and non-p.V600E BRAFmutations. BMC Cancer 2014, 14, 13.
    28. Manfredi, L.; Meyer, N.; Tournier, E.; Grand, D.; Uro-Coste, E.; Rochaix, P.; Brousset, P.; Lamant, L. Highly Concordant Results Between Immunohistochemistry and Molecular Testing of Mutated V600E BRAF in Primary and Metastatic Melanoma. Acta Derm. Venereol. 2016, 96, 630–634.
    29. Anderson, S.; Bloom, K.J.; Vallera, D.U.; Rueschoff, J.; Meldrum, C.; Schilling, R.; Kovach, B.; Lee, J.R.-J.; Ochoa, P.; Langland, R.; et al. Multisite Analytic Performance Studies of a Real-Time Polymerase Chain Reaction Assay for the Detection of BRAF V600E Mutations in Formalin-Fixed, Paraffin-Embedded Tissue Specimens of Malignant Melanoma. Arch. Pathol. Lab. Med. 2012, 136, 1385–1391.
    30. Colomba, E.; Hélias-Rodzewicz, Z.; Von Deimling, A.; Marin, C.; Terrones, N.; Pechaud, D.; Surel, S.; Côté, J.-F.; Peschaud, F.; Capper, D.; et al. Detection of BRAF p.V600E Mutations in Melanomas. J. Mol. Diagn. 2013, 15, 94–100.
    31. Mancini, I.; Simi, L.; Salvianti, F.; Castiglione, F.; Sonnati, G.; Pinzani, P. Simi Analytical Evaluation of an NGS Testing Method for Routine Molecular Diagnostics on Melanoma Formalin-Fixed, Paraffin-Embedded Tumor-Derived DNA. Diagnostics 2019, 9, 117.
    32. Bisschop, C.; ter Elst, A.; Bosman, L.J.; Platteel, I.; Jalving, M.; Berg, A.V.D.; Diepstra, A.; van Hemel, B.; Diercks, G.F.; Hospers, G.A.; et al. Rapid BRAF mutation tests in patients with advanced melanoma: Comparison of immunohistochemistry, Droplet Digital PCR, and the Idylla Mutation Platform. Melanoma Res. 2018, 28, 96–104.
    33. A Monzon, F.; Ogino, S.; Hammond, M.E.H.; Halling, K.C.; Bloom, K.J.; Nikiforova, M.N. The role of KRAS mutation testing in the management of patients with metastatic colorectal cancer. Arch. Pathol. Lab. Med. 2009, 133, 1600–1606.
    34. Tsiatis, A.C.; Norris-Kirby, A.; Rich, R.G.; Hafez, M.J.; Gocke, C.D.; Eshleman, J.R.; Murphy, K.M. Comparison of Sanger Sequencing, Pyrosequencing, and Melting Curve Analysis for the Detection of KRAS Mutations: Diagnostic and Clinical Implications. J. Mol. Diagn. 2010, 12, 425–432.
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