V-raf murine sarcoma viral oncogene homolog B1 ( BRAF V600E) mutations are found in more than half of pleomorphic xanthoastrocytomas (PXA) and gangliogliomas, 2 rare primary brain tumors mainly affecting children and young adults.1 While patients with low-grade PXA and ganglioglioma typically carry a relatively favorable prognosis, clinicopathologic features such as older age, malignant histopathologic characteristics, as well as loss of p16/ CDKN2A are associated with aggressive behavior and unfavorable outcome.2 The BRAF inhibitor (BRAFi) vemurafenib showed activity in patients with BRAF V600E-mutant anaplastic PXA and ganglioglioma,3 representing one of the most significant successes of targeted therapy in gliomas over the past years. However, and as expected from experience in other cancers, acquired resistance to vemurafenib invariably develops. To date, there is no satisfactory therapeutic option for patients that have progressed on vemurafenib. Studies in BRAF V600E-mutant melanoma showed that a subset of tumors develop resistance to BRAFi through molecular events reactivating the mitogen-activated protein kinase (MAPK) pathway, such as NRAS , KRAS , or MEK mutations.4 This provided rationale for combined BRAF/MEK inhibition, which demonstrated superior outcomes in comparison to BRAFi monotherapy in BRAF V600E-mutant melanoma.5 We hypothesized that acquired resistance to vemurafenib may result from persistent MAPK activation in anaplastic ganglioglioma, and that combined BRAF/MEK inhibition could overcome resistance. In support of this, we report that combined treatment with vemurafenib and the MEK inhibitor cobimetinib resulted in major clinical benefit in a patient with refractory BRAF V600E-mutant anaplastic ganglioglioma who had progressed while receiving single-agent vemurafenib.
Abstract The genetic alterations involved in the development lung adenocarcinoma (ADC) have been widely characterized allowing the identification of the most frequent oncogenes or tumor suppressor genes linked to this malignancy. Most studies have focus on proliferation pathway, anti-apoptotic factors or cell cycle alterations. Here we show that alterations in chromatin remodeling complexes are frequent in lung ADC. Chromatin structure plays a key role in the regulation of tissue-specific gene expression during development and differentiation therefore it is not surprising that proteins implicated in remodeling complexes play a role in cancer development. For example, mutations have been found in genes belonging to the SWI/SNF complex in different tumors. In lung cancer BRG1 knockout was shown to potentiate tumor development and mutations were recently identified in tumors by the use of a very sensitive method: massive parallel DNA pyrosequencing that suggests the presence of the alteration in cell subclones. In the course of identifying novel chromatin remodeling complex genes implicated in lung ADC development we analyzed a series of 82 lung adenocarcinomas by SNP array and looked for the presence of homozygous deletions on the entire genome. Three regions of homozygous deletions in known tumor suppressor genes CDKN2A, FHIT and PTEN and in JARID2, which is involved in chromatin remodeling, were found in more than 2 samples. Another ARID-domain containing gene; ARID2 was found deleted in one sample and we therefore decided to screen both ARID-domain genes for mutations by direct sequencing on cryopreserved tumor tissues. One missense somatic mutation was found in JARID2 and 6/82 tumors had ARID2 alterations predicted to inactivate the protein in at least 4 out of 6 samples. Indeed 3 mutations were frameshift or non-sense, one specimen had a homozygous deletion and 4 tumors demonstrated loss of heterozygosity associated to the mutation. Our results indicate that ARID2 inactivation is a common feature of lung cancer development and provide new insight on the impact of chromatin remodeling alteration in lung ADC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5121. doi:1538-7445.AM2012-5121
Abstract Introduction: With the increasing complexity of current diagnostic investigations, the integration of clinical, pathological and molecular characteristics is crucial for the management of patients (pts) with cancers of unknown primary (CUP). A national multidisciplinary tumor board (NatCUPMTB) was created 2 years ago in France to discuss the diagnostic and therapeutic management of CUP pts. The objective of this study was to evaluate its diagnostic, prognostic and therapeutic impact after 2 years of activity. Methods: This was a multicenter retrospective study with prospective follow-up. All pts discussed at least once in the NatCUPMTB between June 2020 and August 2022 were included. Pts and tumors characteristics, pathological and molecular analyses including WGS, WES and RNAseq performed on SEQOIA and AURAGEN national large-scale sequencing platforms, multidisciplinary tumor board (MTB) conclusions, and follow-up after MTB were collected. Results: 76 pts for whom a long-term follow-up was available were included. The median age at diagnosis was 57 yo, 54% were female, and the median number of metastatic sites at diagnosis was 2. The median time between diagnosis and first MTB presentation was 3.8 months (0.2-55). MTB investigations enabled to identify a likely primary origin in 44/76 (58%) pts, and the MTB recommended a personalized therapeutic strategy in 50/76 patients (66%). MTB recommendations were based on the combination of clinical, pathological and molecular investigations in 55% of pts. After a median follow-up of 6.2 months, the median overall survival (OS) was 17.7 months from diagnosis and 11.0 months from the 1st MTB presentation. Pts for which the MTB had a diagnostic impact, and having received a treatment following MTB recommendation (based on putative origin or targetable alteration) had increased OS compared to pts with no diagnostic orientation (median OS 18.4 months vs 5.6 months, p=0.003) or having received other treatments (median OS 18.4 vs 4.4 months, p=0.0001). Conclusion: NatCUPMTB provides significant diagnostic and therapeutic benefit in pts with CUP. Early presentation of pts at NatCUPMTB as soon as CUP diagnosis is suspected should be recommended. Citation Format: Nicolas Jacquin, Maud Kamal, Ivan Bieche, Célia Dupain, Isabelle Guillou, Linda Larbi-Chérif, Etienne Rouleau, Julien Masliah Planchon, Isabelle Soubeyran, Christelle de la Fouchardière, Camille Tlemsani, Hélène Blons, Fabienne Escande, Michel Vidaud, Jennifer Wong, Pierre Saintigny, Sandrine Boyault, Adrien Buisson, Yves Allory, Anne Vincent-Salomon, Vincent Cockenpot, Janick Selves, Christophe Le Tourneau, Sarah Watson. National Multidisciplinary Tumor Board improves diagnostic stratification and therapeutic management in Cancers of Unknown Primary: the French Experience. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4534.
ALK rearrangement and EGFR / KRAS mutations constitute the primary biomarkers tested to provide targeted or nontargeted therapies in advanced nonsmall cell lung cancer (NSCLC) patients. Our objective was to assess the cost-effectiveness of biomarker testing for NSCLC. Between 2013 and 2014, 843 treatment-naive patients were prospectively recruited at 19 French hospitals into a longitudinal observational cohort study. Two testing strategies were compared, i.e. with “at least one biomarker status known” and “at least KRAS status known”, in addition to “no biomarker testing” as the reference strategy. The Kaplan–Meier approach was employed to assess restricted mean survival time. Direct medical costs incurred by hospitals were estimated with regard to treatment, inpatient care and biomarker testing. Compared with “no biomarker testing”, the “at least one biomarker status known” strategy yielded an incremental cost-effectiveness ratio of EUR13 230 per life-year saved, which decreased to EUR7444 per life-year saved with the “at least KRAS status known” testing strategy. In sensitivity analyses, biomarker testing strategies were less costly and more effective in 41% of iterations. In summary, molecular testing prior to treatment initiation proves to be cost-effective in advanced NSCLC management and may assist decision makers in defining conditions for further implementation of these innovations in general practice.
Malignant tumours of the salivary glands (MSGT) are rare and pleomorphic entities. Patients with advanced disease may benefit from targeted therapy; however, specific targets for optimising and personalising treatments are yet to be identified.Immunohistochemistry for C-KIT, EGFR, HER2, MUC1, phospho-mTOR, androgen/estrogens/progesterone receptors and Ki67 was carried out and evaluated in terms of progression-free and overall survival. High throughput molecular screening of key oncogenes was done in 107 patients using routine diagnostic methods and Sequenom technology.Several therapy leads were identified, including high levels of HER2 and androgen receptors in salivary duct carcinomas, C-KIT in myoepithelial carcinomas and EGFR in mucoepidermoid carcinomas. Recurrent mutations involving downstream elements of the EGFR pathway were found in HRAS, notably in tumours with a myoepithelial component, and in other key oncogenes (KRAS/NRAS/PI3KCA/BRAF/MAP2K). On the other hand, <1% of samples had EGFR or HER2 mutations.Several tumour subtypes overexpressed targets of directed therapies suggesting potential therapy leads. Genotyping results suggest activation downstream of EGFR in 18 of the 107 samples that could be associated with low efficacy of EGFR inhibitors. Other molecules, such as PI3K/MEK or mTOR inhibitors, may have anti-tumour activity in this subgroup. The high mutation rate in HRAS highlights a novel key oncogenic event in MSGT.
