sábado, 29 de junio de 2019

Langerhans Cell Histiocytosis Treatment (PDQ®) 1/7 —Health Professional Version - National Cancer Institute

Langerhans Cell Histiocytosis Treatment (PDQ®)—Health Professional Version - National Cancer Institute



National Cancer Institute

Langerhans Cell Histiocytosis Treatment (PDQ®)–Health Professional Version

Go to Patient Version

General Information About Langerhans Cell Histiocytosis (LCH)

The histiocytic diseases in children and adults are caused by an abnormal accumulation of cells of the mononuclear phagocytic system. Only Langerhans cell histiocytosis (LCH), a myeloid-derived dendritic cell disorder, is discussed in detail in this summary.
The histiocytic diseases have been reclassified into five categories, and LCH is in the L group.[1] LCH results from the clonal proliferation of immunophenotypically and functionally immature, morphologically rounded LCH cells along with eosinophils, macrophages, lymphocytes, and, occasionally, multinucleated giant cells.[2,3] The term LCH cells is used because there are clear morphologic, phenotypic, and gene expression differences between Langerhans cells of the epidermis (LCs) and those in LCH lesions (LCH cells), despite the pathologic histiocyte having the identical immunophenotypic characteristics of normal epidermal LCs, including the presence of Birbeck granules identified by electron microscopy.
LCH cells, known for many years to be caused by a clonal proliferation, have now been shown to likely derive from a myeloid precursor whose proliferation is uniformly associated with activation of the MAPK/ERK signaling pathway.[4,5] However, the somatic mutation leading to the activation varies and is unknown in 10% to 20% of cases.[6] In the original breakthrough description of the BRAF V600E mutation occurring in approximately 60% of LCH biopsy specimens, the authors also described activation of the RAS-RAF-MEK-ERK pathway in almost all cases, regardless of stage and organ involvement.[7,8] Since then, activating mutations in several other genes in the pathway have been identified in a significant percentage of BRAF V600E–negative LCH specimens, including MAP2K1, in-frame deletions plus another leading to upregulation of BRAF, and, less frequently, the CSF-1 receptor, RAS, and ARAF.[9-11]
In accordance with these findings, the pathologic histiocyte or LCH cell has a gene expression profile closely resembling that of a myeloid dendritic cell. Studies have also demonstrated that the BRAF V600E mutation can be identified in mononuclear cells in peripheral blood and cell-free DNA, usually in patients with disseminated disease.[2,12,13] This shows that multisystem LCH arises from a somatic mutation within a marrow or circulating precursor cell, while localized disease arises from the mutation occurring in a precursor cell at the local site.[2]
The above findings have led all clinicians to agree that LCH is a myeloid neoplasm; however, discussion remains about whether it is a malignant neoplasm with varying clinical behavior. The same BRAF V600E mutation has been found in other cancers, including malignant melanoma; however, V600E-mutated BRAF is also present in benign nevi, possibly indicating the need for additional mutations to render the cell malignant.[7] Nevertheless, these findings have raised the possibility of targeted therapy with inhibitors already used in the treatment of melanoma. Several trials of BRAF inhibitors are open for adults and children with BRAF V600E–mutated tumors, including LCH.
(Refer to the Cytogenetic and Genomic Studies and Cytokine Analysis by Immunohistochemical Staining and Gene Expression Array Studies sections of this summary for more information.)
LCH may involve a single organ (single-system LCH), which may be a single site (unifocal) or involve multiple sites (multifocal); or LCH may involve multiple organs (multisystem LCH), which may involve a limited number of organs or be disseminated. Involvement of specific organs such as the liver, spleen, and hematopoietic system separates multisystem LCH into a high-risk group and a low-risk group, where risk indicates the risk of death from disease.
References
  1. Emile JF, Abla O, Fraitag S, et al.: Revised classification of histiocytoses and neoplasms of the macrophage-dendritic cell lineages. Blood 127 (22): 2672-81, 2016. [PUBMED Abstract]
  2. Berres ML, Lim KP, Peters T, et al.: BRAF-V600E expression in precursor versus differentiated dendritic cells defines clinically distinct LCH risk groups. J Exp Med 211 (4): 669-83, 2014. [PUBMED Abstract]
  3. Allen CE, Merad M, McClain KL: Langerhans-Cell Histiocytosis. N Engl J Med 379 (9): 856-868, 2018. [PUBMED Abstract]
  4. Willman CL, Busque L, Griffith BB, et al.: Langerhans'-cell histiocytosis (histiocytosis X)--a clonal proliferative disease. N Engl J Med 331 (3): 154-60, 1994. [PUBMED Abstract]
  5. Yu RC, Chu C, Buluwela L, et al.: Clonal proliferation of Langerhans cells in Langerhans cell histiocytosis. Lancet 343 (8900): 767-8, 1994. [PUBMED Abstract]
  6. Monsereenusorn C, Rodriguez-Galindo C: Clinical Characteristics and Treatment of Langerhans Cell Histiocytosis. Hematol Oncol Clin North Am 29 (5): 853-73, 2015. [PUBMED Abstract]
  7. Badalian-Very G, Vergilio JA, Fleming M, et al.: Pathogenesis of Langerhans cell histiocytosis. Annu Rev Pathol 8: 1-20, 2013. [PUBMED Abstract]
  8. Badalian-Very G, Vergilio JA, Degar BA, et al.: Recurrent BRAF mutations in Langerhans cell histiocytosis. Blood 116 (11): 1919-23, 2010. [PUBMED Abstract]
  9. Chakraborty R, Hampton OA, Shen X, et al.: Mutually exclusive recurrent somatic mutations in MAP2K1 and BRAF support a central role for ERK activation in LCH pathogenesis. Blood 124 (19): 3007-15, 2014. [PUBMED Abstract]
  10. Nelson DS, van Halteren A, Quispel WT, et al.: MAP2K1 and MAP3K1 mutations in Langerhans cell histiocytosis. Genes Chromosomes Cancer 54 (6): 361-8, 2015. [PUBMED Abstract]
  11. Chakraborty R, Burke TM, Hampton OA, et al.: Alternative genetic mechanisms of BRAF activation in Langerhans cell histiocytosis. Blood 128 (21): 2533-2537, 2016. [PUBMED Abstract]
  12. Allen CE, Li L, Peters TL, et al.: Cell-specific gene expression in Langerhans cell histiocytosis lesions reveals a distinct profile compared with epidermal Langerhans cells. J Immunol 184 (8): 4557-67, 2010. [PUBMED Abstract]
  13. Hyman DM, Diamond EL, Vibat CR, et al.: Prospective blinded study of BRAFV600E mutation detection in cell-free DNA of patients with systemic histiocytic disorders. Cancer Discov 5 (1): 64-71, 2015. [PUBMED Abstract]

Histopathologic, Immunologic, and Cytogenetic Characteristics of LCH

Cell of Origin and Biologic Correlates

Modern classification of the histiocytic diseases subdivides them into dendritic cell–related, monocyte/macrophage-related, or true malignancies. Langerhans cell histiocytosis (LCH) is a dendritic cell disease.[1,2] Comprehensive gene expression array data analysis on LCH cells is consistent with the concept that the skin Langerhans cell (LC) is not the cell of origin for LCH.[3] Rather, it is likely to be a hematopoietic progenitor cell before being a committed myeloid dendritic cell, which expresses the same antigens (CD1a and CD207) as the skin LC.[4,5] This concept was further supported by reports that the transcription profile of LCH cells was distinct from myeloid and plasmacytoid dendritic cells, as well as epidermal LCs.[3,4,6,7]

Histopathology

The Langerhans histiocytosis cells in LCH lesions (LCH cells) are immature dendritic cells making up fewer than 10% of the cells present in the lesion.[7,8] These cells are classically large oval cells with abundant pink cytoplasm and a bean-shaped nucleus on hematoxylin and eosin stain. LCH cells stain positively with antibodies to S100, CD1a, and/or anti-Langerin (CD207). Staining with CD1a or Langerin confirm the diagnosis of LCH, but care should be taken to correlate with clinical presentation in organs in which normal LC cells occur.[9]
Because LCH cells activate other immunologic cells, LCH lesions also contain other histiocytes, lymphocytes, macrophages, neutrophils, eosinophils, and fibroblasts, and may contain multinucleated giant cells.
In the brain, the following three types of histopathologic findings have been described in LCH:
  1. Mass lesions in the meninges or choroid plexus with CD1a-positive LCH cells and predominantly CD8-positive lymphocytes.
  2. Mass lesions in connective tissue spaces with CD1a-positive LCH cells and predominantly CD8-positive lymphocytes that cause an inflammatory response and neuronal loss.
  3. Neurodegenerative lesions. Predominantly CD8-positive lymphocyte infiltration with neuronal degeneration, microglial activation, and gliosis.[10]

Immunologic Abnormalities

Normally, the LC is a primary presenter of antigen to naïve T-lymphocytes. However, in LCH, the pathologic dendritic cell does not efficiently stimulate primary T-lymphocyte responses.[11] Antibody staining for the dendritic cell markers, including CD80, CD86, and class II antigens, has been used to show that in LCH, the abnormal cells are immature dendritic cells that present antigen poorly and are proliferating at a low rate.[8,11,12] Transforming growth factor-beta (TGF-beta) and interleukin (IL)-10 may be responsible for preventing LCH cell maturation in LCH.[8] The expansion of regulatory T cells in patients with LCH has been reported.[12] The population of CD4-positive CD25(high) FoxP3(high) cells was reported to comprise 20% of T cells and appeared to be in contact with LCH cells in the lesions. These T cells were present in higher numbers in the peripheral blood of patients with LCH than in the peripheral blood of control patients and returned to a normal level when patients were in remission.[12]

Cytogenetic and Genomic Studies

Studies published in 1994 showed clonality in Langerhans cell histiocytosis (LCH) using polymorphisms of methylation-specific restriction enzyme sites on the X-chromosome regions coding for the human androgen receptor, DXS255, PGK, and HPRT.[13,14] The results of biopsies of lesions with single-system or multisystem disease showed a proliferation of LCH cells from a single clone. The discovery of recurring genomic alterations (primarily BRAF V600E) in LCH (see below) confirmed the clonality of LCH in children.
Pulmonary LCH in adults was initially reported to be nonclonal in approximately 75% of cases,[15] while an analysis of BRAF mutations showed that 25% to 50% of adult lung LCH patients had evidence of BRAF V600E mutations.[15,16] Another study of 26 pulmonary LCH cases found that 50% had BRAF V600E mutations and 40% had NRAS mutations.[17] Approximately the same number of mutations are polyclonal, rather than monoclonal. It has not yet been investigated whether clonality and BRAF pathway mutations are concordant in the same patients, which might suggest a reactive rather than a neoplastic condition in smoker's lung LCH and a clonal neoplasm in other types of LCH.
ENLARGEBRAF-RAS pathway
Figure 1. Courtesy of Rikhia Chakraborty, Ph.D. Permission to reuse the figure in any form must be obtained directly from Dr. Chakraborty.
The genomic basis of LCH was advanced by a 2010 report of an activating mutation of the BRAF oncogene (V600E) that was detected in 35 of 61 cases (57%).[18] Multiple subsequent reports have confirmed the presence of BRAF V600E mutations in 50% or more of LCH cases in children.[19-21] Other BRAF mutations that result in signal activation have been described.[20,22] ARAF mutations are infrequent in LCH but, when present, can also lead to RAS-MAPK pathway activation.[23]
The RAS-MAPK signaling pathway (refer to Figure 1) transmits signals from a cell surface receptor (e.g., a growth factor) through the RAS pathway (via one of the RAF proteins [A, B, or C]) to phosphorylate MEK and then the extracellular signal-regulated kinase (ERK), which leads to nuclear signals affecting cell cycle and transcription regulation. The V600E mutation of BRAF leads to continuous phosphorylation, and thus activation, of MEK and ERK without the need for an external signal. Activation of ERK occurs by phosphorylation, and phosphorylated ERK can be detected in virtually all LCH lesions.[18,24]
Because RAS-MAPK pathway activation can be detected in all LCH cases, but not all cases have BRAF mutations, the presence of genomic alterations in other components of the pathway was suspected. The following genomic alterations were identified:
  • Whole-exome sequencing of BRAF-mutated versus BRAF–wild-type LCH biopsy tissue samples revealed that 7 of 21 BRAF–wild-type specimens had MAP2K1 mutations, while no BRAF-mutated specimens had MAP2K1 mutations.[24] The mutations in MAP2K1(which codes for MEK) were activating, as indicated by their induction of ERK phosphorylation.[24]
  • Another study showed MAP2K1 mutations exclusively in 11 of 22 BRAF–wild-type cases.[25]
  • Finally, in-frame BRAF deletions and in-frame FAM73A-BRAF fusions have occurred in the group of BRAF V600E and MAP2K1 mutation–negative cases.[26]
Studies support the universal activation of ERK in LCH, with activation in most cases being explained by BRAF and MAP2K1 alterations.[18,24,26] Altogether, these mutations in the MAP kinase pathway account for nearly 90% of the causes of the universal activation of ERK in LCH.[18,24,26]
The presence of the BRAF V600E mutation in blood and bone marrow was studied in a series of 100 patients, 65% of whom tested positive for the BRAF V600E mutation by a sensitive quantitative polymerase chain reaction technique.[19] Circulating cells with the BRAF V600E mutation could be detected in all high-risk patients and in a subset of low-risk multisystem patients. The presence of circulating cells with the mutation conferred a twofold increased risk of relapse. In a similar study that included 48 patients with BRAFV600E–mutated LCH, the BRAF V600E allele was detected in circulating cell-free DNA in 100% of patients with risk-organ–positive multisystem LCH, 42% of patients with risk-organ–negative LCH, and 14% of patients with single-system LCH.[27]
The myeloid dendritic cell origin of LCH was confirmed by finding CD34-positive stem cells with the mutation in the bone marrow of high-risk patients. In those with low-risk disease, the mutation was found in more mature myeloid dendritic cells, suggesting that the stage of cell development at which the somatic mutation occurs is critical in defining the extent of disease in LCH. LCH is now considered a myeloid neoplasm.
Clinical implications
Clinical implications of the described genomic findings include the following:
  • LCH joins a group of other pediatric entities with activating BRAF mutations, including select nonmalignant conditions (e.g., benign nevi) [28] and low-grade malignancies (e.g., pilocytic astrocytoma).[29,30] All of these conditions have a generally indolent course, with spontaneous resolution occurring in some cases. This distinctive clinical course may be a manifestation of oncogene-induced senescence.[28,31]
  • BRAF V600E mutations can be targeted by BRAF inhibitors (e.g., vemurafenib and dabrafenib) or by the combination of BRAF inhibitors plus MEK inhibitors (e.g., dabrafenib/trametinib and vemurafenib/cobimetinib). These agents and combinations are approved for adults with melanoma. Treatment of melanoma in adults with combinations of a BRAF inhibitor and a MEK inhibitor showed significantly improved progression-free survival outcome compared with treatment using a BRAF inhibitor alone.[32,33]
    Case reports have described activity of BRAF inhibitors against LCH in adult patients [34-38] and pediatric patients,[39] but there are insufficient data to assess the role of these agents in the treatment of children with LCH.
    The most serious side effect of BRAF inhibitor therapies is the induction of cutaneous squamous cell carcinomas,[32,33] with the incidence of these second cancers increasing with age;[40] this effect can be reduced by concurrent treatment with both BRAF and MEK inhibitors.[32,33] In a long-term study of adult patients with Erdheim-Chester disease and LCH who received vemurafenib, 85% of patients had arthralgias; 62% of patients had maculopapular rashes; and more than 40% of patients had other skin issues, including hyperkeratosis, seborrheic keratosis, and pruritus.[41]
  • Circulating BRAF V600E–mutated cells have been found in 59% of patients who developed neurodegenerative-disease LCH, compared with 15% of patients who did not develop neurodegenerative-disease LCH. Detectable mutated circulating cells had a sensitivity of 0.59 and specificity of 0.86 for developing the neurodegenerative disease condition. Even after therapy, some patients with neurodegenerative-disease LCH had circulating BRAF V600E–mutated cells.[42]
  • With additional research, the observation of BRAF V600E (or potentially mutated MAP2K1) in circulating cells or cell-free DNA may become a useful diagnostic tool to define high-risk versus low-risk disease.[19] Additionally, for patients who have a somatic mutation, persistence of circulating cells with the mutation may be useful as a marker of residual disease.[19]

Cytokine Analysis

Immunohistochemical staining has shown upregulation of many different cytokines/chemokines, both in lesional tissue and in serum/plasma.[43,44] In an analysis of gene expression in LCH by gene array techniques, 2,000 differentially expressed genes were identified. Of 65 genes previously reported to be associated with LCH, only 11 were found to be upregulated in the array results. The most highly upregulated gene in both CD207-positive and CD3-positive cells was SPP1 (encodes the osteopontin protein); other genes that activate and recruit T cells to sites of inflammation are also upregulated.[3] The expression profile of the T cells was that of an activated regulatory T-cell phenotype with increased expression of FOXP3, CTLA4, and SPP1. These findings support a previous report on the expansion of regulatory T cells in LCH.[3] There was pronounced expression of genes associated with early myeloid progenitors including CD33 and CD44, which is consistent with an earlier report of elevated myeloid dendritic cells in the blood of patients with LCH.[45] A model of Misguided Myeloid Dendritic Cell Precursors has been proposed, whereby myeloid dendritic cell precursors are recruited to sites of LCH by an unknown mechanism, and the dendritic cells, in turn, recruit lymphocytes by excretion of osteopontin, neuropilin-1, and vannin-1.[3]
A study to evaluate possible biomarkers for central nervous system LCH examined 121 unique proteins in the cerebrospinal fluid (CSF) of 40 pediatric patients with LCH and compared them with controls, which included 29 patients with acute lymphoblastic leukemia, 25 patients with brain tumors, 28 patients with neurodegenerative diseases, and 9 patients with hemophagocytic lymphohistiocytosis. Only osteopontin proved to be significantly increased in the CSF of LCH patients with either neurodegeneration or mass lesions (pituitary), compared with all of the control groups. Analysis of osteopontin expression in these tissues confirmed an upregulation of the SPP1 gene.[42]
Several investigators have published studies evaluating the level of various cytokines or growth factors in the blood of patients with LCH that have included many of the genes found not to be upregulated by the gene expression results discussed above.[3] One explanation for elevated levels of these proteins is a systemic inflammatory response, with the cytokines/growth factors being produced by cells outside the LCH lesions. A second possible explanation is that macrophages in the LCH lesions produce the cytokines measured in the blood or are concentrated in lesions.
IL-1 beta and prostaglandin GE2 levels were measured in the saliva of patients with oral LCH lesions or multisystem high-risk patients with and without oral lesions; levels of both were higher in patients with active disease and decreased after successful therapy.[46]

HLA Type and Association With LCH

Specific associations of LCH with distinct HLA types and extent of disease have been reported. In a study of 84 Nordic patients, those with only skin or bone involvement more frequently had HLA-DRB1*03 type than did those with multisystem disease.[47] In 29 patients and 37 family members in the United States, the Cw7 and DR4 types were significantly more prevalent in Caucasians with single-bone lesions.[48]
References
  1. Emile JF, Abla O, Fraitag S, et al.: Revised classification of histiocytoses and neoplasms of the macrophage-dendritic cell lineages. Blood 127 (22): 2672-81, 2016. [PUBMED Abstract]
  2. Picarsic J, Jaffe R: Nosology and Pathology of Langerhans Cell Histiocytosis. Hematol Oncol Clin North Am 29 (5): 799-823, 2015. [PUBMED Abstract]
  3. Allen CE, Li L, Peters TL, et al.: Cell-specific gene expression in Langerhans cell histiocytosis lesions reveals a distinct profile compared with epidermal Langerhans cells. J Immunol 184 (8): 4557-67, 2010. [PUBMED Abstract]
  4. Ginhoux F, Merad M: Ontogeny and homeostasis of Langerhans cells. Immunol Cell Biol 88 (4): 387-92, 2010 May-Jun. [PUBMED Abstract]
  5. Durham BH, Roos-Weil D, Baillou C, et al.: Functional evidence for derivation of systemic histiocytic neoplasms from hematopoietic stem/progenitor cells. Blood 130 (2): 176-180, 2017. [PUBMED Abstract]
  6. Hutter C, Kauer M, Simonitsch-Klupp I, et al.: Notch is active in Langerhans cell histiocytosis and confers pathognomonic features on dendritic cells. Blood 120 (26): 5199-208, 2012. [PUBMED Abstract]
  7. Berres ML, Allen CE, Merad M: Pathological consequence of misguided dendritic cell differentiation in histiocytic diseases. Adv Immunol 120: 127-61, 2013. [PUBMED Abstract]
  8. Geissmann F, Lepelletier Y, Fraitag S, et al.: Differentiation of Langerhans cells in Langerhans cell histiocytosis. Blood 97 (5): 1241-8, 2001. [PUBMED Abstract]
  9. Chikwava K, Jaffe R: Langerin (CD207) staining in normal pediatric tissues, reactive lymph nodes, and childhood histiocytic disorders. Pediatr Dev Pathol 7 (6): 607-14, 2004 Nov-Dec. [PUBMED Abstract]
  10. Grois N, Prayer D, Prosch H, et al.: Neuropathology of CNS disease in Langerhans cell histiocytosis. Brain 128 (Pt 4): 829-38, 2005. [PUBMED Abstract]
  11. Yu RC, Morris JF, Pritchard J, et al.: Defective alloantigen-presenting capacity of 'Langerhans cell histiocytosis cells'. Arch Dis Child 67 (11): 1370-2, 1992. [PUBMED Abstract]
  12. Senechal B, Elain G, Jeziorski E, et al.: Expansion of regulatory T cells in patients with Langerhans cell histiocytosis. PLoS Med 4 (8): e253, 2007. [PUBMED Abstract]
  13. Willman CL, Busque L, Griffith BB, et al.: Langerhans'-cell histiocytosis (histiocytosis X)--a clonal proliferative disease. N Engl J Med 331 (3): 154-60, 1994. [PUBMED Abstract]
  14. Yu RC, Chu C, Buluwela L, et al.: Clonal proliferation of Langerhans cells in Langerhans cell histiocytosis. Lancet 343 (8900): 767-8, 1994. [PUBMED Abstract]
  15. Dacic S, Trusky C, Bakker A, et al.: Genotypic analysis of pulmonary Langerhans cell histiocytosis. Hum Pathol 34 (12): 1345-9, 2003. [PUBMED Abstract]
  16. Roden AC, Hu X, Kip S, et al.: BRAF V600E expression in Langerhans cell histiocytosis: clinical and immunohistochemical study on 25 pulmonary and 54 extrapulmonary cases. Am J Surg Pathol 38 (4): 548-51, 2014. [PUBMED Abstract]
  17. Mourah S, How-Kit A, Meignin V, et al.: Recurrent NRAS mutations in pulmonary Langerhans cell histiocytosis. Eur Respir J 47 (6): 1785-96, 2016. [PUBMED Abstract]
  18. Badalian-Very G, Vergilio JA, Degar BA, et al.: Recurrent BRAF mutations in Langerhans cell histiocytosis. Blood 116 (11): 1919-23, 2010. [PUBMED Abstract]
  19. Berres ML, Lim KP, Peters T, et al.: BRAF-V600E expression in precursor versus differentiated dendritic cells defines clinically distinct LCH risk groups. J Exp Med 211 (4): 669-83, 2014. [PUBMED Abstract]
  20. Satoh T, Smith A, Sarde A, et al.: B-RAF mutant alleles associated with Langerhans cell histiocytosis, a granulomatous pediatric disease. PLoS One 7 (4): e33891, 2012. [PUBMED Abstract]
  21. Sahm F, Capper D, Preusser M, et al.: BRAFV600E mutant protein is expressed in cells of variable maturation in Langerhans cell histiocytosis. Blood 120 (12): e28-34, 2012. [PUBMED Abstract]
  22. Héritier S, Hélias-Rodzewicz Z, Chakraborty R, et al.: New somatic BRAF splicing mutation in Langerhans cell histiocytosis. Mol Cancer 16 (1): 115, 2017. [PUBMED Abstract]
  23. Nelson DS, Quispel W, Badalian-Very G, et al.: Somatic activating ARAF mutations in Langerhans cell histiocytosis. Blood 123 (20): 3152-5, 2014. [PUBMED Abstract]
  24. Chakraborty R, Hampton OA, Shen X, et al.: Mutually exclusive recurrent somatic mutations in MAP2K1 and BRAF support a central role for ERK activation in LCH pathogenesis. Blood 124 (19): 3007-15, 2014. [PUBMED Abstract]
  25. Brown NA, Furtado LV, Betz BL, et al.: High prevalence of somatic MAP2K1 mutations in BRAF V600E-negative Langerhans cell histiocytosis. Blood 124 (10): 1655-8, 2014. [PUBMED Abstract]
  26. Chakraborty R, Burke TM, Hampton OA, et al.: Alternative genetic mechanisms of BRAF activation in Langerhans cell histiocytosis. Blood 128 (21): 2533-2537, 2016. [PUBMED Abstract]
  27. Héritier S, Hélias-Rodzewicz Z, Lapillonne H, et al.: Circulating cell-free BRAF(V600E) as a biomarker in children with Langerhans cell histiocytosis. Br J Haematol 178 (3): 457-467, 2017. [PUBMED Abstract]
  28. Michaloglou C, Vredeveld LC, Soengas MS, et al.: BRAFE600-associated senescence-like cell cycle arrest of human naevi. Nature 436 (7051): 720-4, 2005. [PUBMED Abstract]
  29. Jones DT, Kocialkowski S, Liu L, et al.: Tandem duplication producing a novel oncogenic BRAF fusion gene defines the majority of pilocytic astrocytomas. Cancer Res 68 (21): 8673-7, 2008. [PUBMED Abstract]
  30. Pfister S, Janzarik WG, Remke M, et al.: BRAF gene duplication constitutes a mechanism of MAPK pathway activation in low-grade astrocytomas. J Clin Invest 118 (5): 1739-49, 2008. [PUBMED Abstract]
  31. Jacob K, Quang-Khuong DA, Jones DT, et al.: Genetic aberrations leading to MAPK pathway activation mediate oncogene-induced senescence in sporadic pilocytic astrocytomas. Clin Cancer Res 17 (14): 4650-60, 2011. [PUBMED Abstract]
  32. Larkin J, Ascierto PA, Dréno B, et al.: Combined vemurafenib and cobimetinib in BRAF-mutated melanoma. N Engl J Med 371 (20): 1867-76, 2014. [PUBMED Abstract]
  33. Long GV, Stroyakovskiy D, Gogas H, et al.: Dabrafenib and trametinib versus dabrafenib and placebo for Val600 BRAF-mutant melanoma: a multicentre, double-blind, phase 3 randomised controlled trial. Lancet 386 (9992): 444-51, 2015. [PUBMED Abstract]
  34. Haroche J, Cohen-Aubart F, Emile JF, et al.: Reproducible and sustained efficacy of targeted therapy with vemurafenib in patients with BRAF(V600E)-mutated Erdheim-Chester disease. J Clin Oncol 33 (5): 411-8, 2015. [PUBMED Abstract]
  35. Charles J, Beani JC, Fiandrino G, et al.: Major response to vemurafenib in patient with severe cutaneous Langerhans cell histiocytosis harboring BRAF V600E mutation. J Am Acad Dermatol 71 (3): e97-9, 2014. [PUBMED Abstract]
  36. Gandolfi L, Adamo S, Pileri A, et al.: Multisystemic and Multiresistant Langerhans Cell Histiocytosis: A Case Treated With BRAF Inhibitor. J Natl Compr Canc Netw 13 (6): 715-8, 2015. [PUBMED Abstract]
  37. Euskirchen P, Haroche J, Emile JF, et al.: Complete remission of critical neurohistiocytosis by vemurafenib. Neurol Neuroimmunol Neuroinflamm 2 (2): e78, 2015. [PUBMED Abstract]
  38. Hyman DM, Puzanov I, Subbiah V, et al.: Vemurafenib in Multiple Nonmelanoma Cancers with BRAF V600 Mutations. N Engl J Med 373 (8): 726-36, 2015. [PUBMED Abstract]
  39. Héritier S, Jehanne M, Leverger G, et al.: Vemurafenib Use in an Infant for High-Risk Langerhans Cell Histiocytosis. JAMA Oncol 1 (6): 836-8, 2015. [PUBMED Abstract]
  40. Anforth R, Menzies A, Byth K, et al.: Factors influencing the development of cutaneous squamous cell carcinoma in patients on BRAF inhibitor therapy. J Am Acad Dermatol 72 (5): 809-15.e1, 2015. [PUBMED Abstract]
  41. Diamond EL, Subbiah V, Lockhart AC, et al.: Vemurafenib for BRAF V600-Mutant Erdheim-Chester Disease and Langerhans Cell Histiocytosis: Analysis of Data From the Histology-Independent, Phase 2, Open-label VE-BASKET Study. JAMA Oncol 4 (3): 384-388, 2018. [PUBMED Abstract]
  42. McClain KL, Picarsic J, Chakraborty R, et al.: CNS Langerhans cell histiocytosis: Common hematopoietic origin for LCH-associated neurodegeneration and mass lesions. Cancer 124 (12): 2607-2620, 2018. [PUBMED Abstract]
  43. Fleming MD, Pinkus JL, Fournier MV, et al.: Coincident expression of the chemokine receptors CCR6 and CCR7 by pathologic Langerhans cells in Langerhans cell histiocytosis. Blood 101 (7): 2473-5, 2003. [PUBMED Abstract]
  44. Annels NE, Da Costa CE, Prins FA, et al.: Aberrant chemokine receptor expression and chemokine production by Langerhans cells underlies the pathogenesis of Langerhans cell histiocytosis. J Exp Med 197 (10): 1385-90, 2003. [PUBMED Abstract]
  45. Rolland A, Guyon L, Gill M, et al.: Increased blood myeloid dendritic cells and dendritic cell-poietins in Langerhans cell histiocytosis. J Immunol 174 (5): 3067-71, 2005. [PUBMED Abstract]
  46. Preliasco VF, Benchuya C, Pavan V, et al.: IL-1 beta and PGE2 levels are increased in the saliva of children with Langerhans cell histiocytosis. J Oral Pathol Med 37 (9): 522-7, 2008. [PUBMED Abstract]
  47. Bernstrand C, Carstensen H, Jakobsen B, et al.: Immunogenetic heterogeneity in single-system and multisystem langerhans cell histiocytosis. Pediatr Res 54 (1): 30-6, 2003. [PUBMED Abstract]
  48. McClain KL, Laud P, Wu WS, et al.: Langerhans cell histiocytosis patients have HLA Cw7 and DR4 types associated with specific clinical presentations and no increased frequency in polymorphisms of the tumor necrosis factor alpha promoter. Med Pediatr Oncol 41 (6): 502-7, 2003. [PUBMED Abstract]
Publicado por en

No hay comentarios:

Publicar un comentario

Suscribirse a: Enviar comentarios (Atom)