RESUMO
Thymoma and thymic carcinoma are thymic epithelial tumors (TETs). We performed a molecular profiling to investigate the pathogenesis of TETs and identify novel targets for therapy. We analyzed 37 thymomas (18 type A, 19 type B3) and 35 thymic carcinomas. The sequencing of 50 genes detected nonsynonymous mutations in 16 carcinomas affecting ALK, ATM, CDKN2A, ERBB4, FGFR3, KIT, NRAS and TP53. Only two B3 thymomas had a mutation in noncoding regions of the SMARCB1 and STK11 gene respectively. Three type A thymomas harbored a nonsynonymous HRAS mutation. Fluorescence in situ hybridization detected in 38 % of carcinomas a CDKN2A, in 32 % a TP53 and in 8 % an ATM gene deletion, whereas only one B3 thymoma exhibited a CDKNA deletion, and none of the type A thymomas showed a gene loss. Sequencing of the total miRNA pool of 5 type A thymomas and 5 thymic carcinomas identified the C19MC miRNA cluster as highly expressed in type A thymomas, but completely silenced in thymic carcinomas. Furthermore, the miRNA cluster C14MC was downregulated in thymic carcinomas. Among non-clustered miRNAs, the upregulation of miR-21, miR-9-3 and miR-375 and the downregulation of miR-34b, miR-34c, miR-130a and miR-195 in thymic carcinomas were most significant. The expression of ALK, HER2, HER3, MET, phospho-mTOR, p16INK4A, PDGFRA, PDGFRB, PD-L1, PTEN and ROS1 was investigated by immunohistochemistry. PDGFRA was increased in thymic carcinomas and PD-L1 in B3 thymomas and thymic carcinomas. In summary, our results reveal genetic differences between thymomas and thymic carcinomas and suggest potential novel targets for therapy.
Assuntos
Mutação/genética , Timoma/genética , Biomarcadores Tumorais/genética , Humanos , Imuno-Histoquímica/métodos , Hibridização in Situ Fluorescente/métodos , MicroRNAs/genética , Neoplasias Epiteliais e Glandulares/genética , Neoplasias do Timo/genéticaRESUMO
MYC and BCL2 translocations as well as TP53 deletion/mutation are known risk factors in diffuse large B-cell lymphoma (DLBCL) but their interplay is not well understood.In this retrospective cohort study, we evaluated the combined prognostic impact of TP53 deletion and mutation status, MYC and BCL2 genomic breaks in tumor samples of 101 DLBCL patients. The cohort included 53 cases with MYC rearrangements (MYC+).TP53 deletions/mutations (TP53+) were found in 32 of 101 lymphomas and were equally distributed between MYC+ and MYC- cases (35.8% vs. 27.1%). TP53+ lymphomas had lower responses to treatment than TP53- (complete remission 34.4% vs. 60.9%; Pâ=â0.01). TP53 alteration was the dominant independent prognostic factor in multivariate analysis (Pâ=â0.01). Overall survival (OS) varied considerably between subgroups with different genomic alterations: Patients with sole MYC translocation, and interestingly, with triple MYC+/BCL2+/TP53+ aberration had favorable outcomes (median OS not reached) similar to patients without genomic alterations (median OS 65 months). In contrast, patients with MYC+/BCL2+/TP53- double-hit lymphomas (DHL) (28 months), MYC+/BCL2-/TP53+ lymphomas (10 months) or sole TP53 mutation/deletion (12 months) had a poor median OS. Our findings demonstrate differences in OS of DLBCL patients depending on absence or presence of single or combined genetic alterations of MYC, BCL2, and TP53. Cooccurrence of TP53 and BCL2 aberrations ameliorated the poor prognostic impact of single TP53+ or BCL2+ in MYC positive patients.This pilot study generates evidence for the complex interplay between the alterations of genetic pathways in DLBCL, which goes beyond the concept of DHL. The variable survival of DLBCL patients dependent on single or combined alterations in the TP53, MYC, and BCL2 genes indicates the need for comprehensive genomic diagnosis.
Assuntos
Linfoma Difuso de Grandes Células B/genética , Polimorfismo Genético , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-myc/genética , Proteína Supressora de Tumor p53/genética , Adulto , Feminino , Humanos , Hibridização in Situ Fluorescente , Estimativa de Kaplan-Meier , Linfoma Difuso de Grandes Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Deleção de Sequência , Translocação GenéticaRESUMO
PURPOSE: To discuss the potential contribution of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (FDG-PET) in radiotherapy planning for non-small-cell lung cancer (NSCLC) considering new concepts on target volume definition. PROCEDURES: Recent investigations on the topic are reviewed with regard to current concepts of target volume definition for NSCLC. RESULTS: As intrathoracic recurrence is the leading cause of death after primary radiotherapy of NSCLC, there is a need for improving local control by escalating treatment intensity to gross disease. The value of elective nodal irradiation (ENI), resembling prophylactic irradiation of macroscopically unaffected parts of the mediastinum, is being considered. CONCLUSION: As FDG-PET has been shown to enhance the diagnostic accuracy of computed tomography (CT), and to have a potentially high impact on the identification of malignant tissue, it should be implicated in prospective clinical trials on dose escalation and three-dimensional conformal radiotherapy, especially in those including a reduction of target volumes.