RESUMO
BACKGROUND: Targeted therapies have transformed clinical management of advanced biliary tract cancer (BTC). Cell-free DNA (cfDNA) analysis is an attractive approach for cancer genomic profiling that overcomes many limitations of traditional tissue-based analysis. We examined cfDNA as a tool to inform clinical management of patients with advanced BTC and generate novel insights into BTC tumor biology. PATIENTS AND METHODS: We analyzed next-generation sequencing data of 2068 cfDNA samples from 1671 patients with advanced BTC generated with Guardant360. We carried out clinical annotation on a multi-institutional subset (n = 225) to assess intra-patient cfDNA-tumor concordance and the association of cfDNA variant allele fraction (VAF) with clinical outcomes. RESULTS: Genetic alterations were detected in cfDNA in 84% of patients, with targetable alterations detected in 44% of patients. Fibroblast growth factor receptor 2 (FGFR2) fusions, isocitrate dehydrogenase 1 (IDH1) mutations, and BRAF V600E were clonal in the majority of cases, affirming these targetable alterations as early driver events in BTC. Concordance between cfDNA and tissue for mutation detection was high for IDH1 mutations (87%) and BRAF V600E (100%), and low for FGFR2 fusions (18%). cfDNA analysis uncovered novel putative mechanisms of resistance to targeted therapies, including mutation of the cysteine residue (FGFR2 C492F) to which covalent FGFR inhibitors bind. High pre-treatment cfDNA VAF was associated with poor prognosis and shorter response to chemotherapy and targeted therapy. Finally, we report the frequency of promising targets in advanced BTC currently under investigation in other advanced solid tumors, including KRAS G12C (1.0%), KRAS G12D (5.1%), PIK3CA mutations (6.8%), and ERBB2 amplifications (4.9%). CONCLUSIONS: These findings from the largest and most comprehensive study to date of cfDNA from patients with advanced BTC highlight the utility of cfDNA analysis in current management of this disease. Characterization of oncogenic drivers and mechanisms of therapeutic resistance in this study will inform drug development efforts to reduce mortality for patients with BTC.
Assuntos
Neoplasias dos Ductos Biliares , Neoplasias do Sistema Biliar , Ácidos Nucleicos Livres , Humanos , Ácidos Nucleicos Livres/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Neoplasias dos Ductos Biliares/genética , Sequenciamento de Nucleotídeos em Larga Escala , Mutação , Neoplasias do Sistema Biliar/tratamento farmacológico , Neoplasias do Sistema Biliar/genética , Neoplasias do Sistema Biliar/patologiaRESUMO
BACKGROUND: The insurgence of resistance to key drugs of the BPaLM (bedaquiline + pretomanid + moxifloxacin) regimen is a major concern. In settings with widespread resistance to fluoroquinolones (FQs), like Pakistan, new technologies, such as Xpert® MTB/XDR, may ensure drug resistance upfront screening. This study aims to assess MTB/XDR's performance in detecting FQs and isoniazid resistance, proposing a renewed diagnostic algorithm for drug-resistant TB (DR-TB). METHODS: This cross-sectional prospective study, approved by the local ethical committee, collected samples from people newly and previously diagnosed with TB over 6 months. Xpert® MTB/RIF Ultra, MTB/XDR, Genotype® MTBDRplus, Genotype® MTBDRsl, culture, and phenotypic drug susceptibility testing (pDST) for relevant drugs (including bedaquiline and levofloxacin) were performed. Next-generation sequencing (NGS) resolved discordances between MTB/XDR and pDST results. RESULTS: The analysis showed that MTB/XDR has 91.5% and 88.2% sensitivity and 99.5% and 97.7% specificity in detecting respectively isoniazid (INH) and resistance to FQs, demonstrating that MTB/XDR meets the WHO targets for INH resistance detection at the peripheral level. NGS effectively resolved discordances between MTB/XDR and pDST results. CONCLUSIONS: The obtained results allowed designing the proposed diagnostic algorithm for rapid identification of DR-TB, ensuring rapid and equitable access to drug susceptibility testing for TB, ultimately improving TB care and control.
CONTEXTE: La recrudescence de la résistance aux médicaments clés du régime BPaLM (bédaquiline + prétomanide + moxifloxacine) est une préoccupation majeure. Dans les contextes où la résistance aux fluoroquinolones (FQ) est répandue, comme le Pakistan, de nouvelles technologies, telles que Xpert® MTB/XDR, peuvent assurer un dépistage initial de la résistance aux médicaments. Cette étude vise à évaluer la performance de MTB/XDR dans la détection des FQ et de la résistance à l'isoniazide, en proposant un algorithme de diagnostic renouvelé pour la TB pharmacorésistante (DR-TB, pour l'anglais «drug-resistant TB ¼ ). MÉTHODES: Cette étude prospective transversale, approuvée par le comité d'éthique local, a recueilli des échantillons de personnes nouvellement diagnostiquées et précédemment diagnostiquées avec la TB pendant 6 mois. Xpert® MTB/RIF Ultra, MTB/XDR, le GenoType® MTBDRplus, le GenoType® MTBDRsl, la culture et des tests phénotypiques de sensibilité aux médicaments (pDST, pour l'anglais «phenotypic drug susceptibility testing ¼ ) pour les médicaments pertinents (y compris la bédaquiline et la lévofloxacine) ont été effectués. Le séquençage de nouvelle génération (NGS, pour l'anglais «next-generation sequencing ¼ ) a résolu les discordances entre les résultats MTB/XDR et pDST. RÉSULTATS: L'analyse a montré que le MTB/XDR a une sensibilité de 91,5% et 88,2% et une spécificité de 99,5% et 97,7% dans la détection respectivement de l'isoniazide et de la résistance aux FQ, démontrant que le MTB/XDR répond aux objectifs de l'OMS pour la détection de la résistance à l'isoniazide au niveau périphérique. NGS a efficacement résolu les discordances entre les résultats MTB/XDR et pDST. CONCLUSIONS: Les résultats obtenus ont permis de concevoir l'algorithme de diagnostic proposé pour l'identification rapide de la DR-TB, garantissant un accès rapide et équitable aux tests de sensibilité aux médicaments pour la TB, améliorant ainsi la prise en charge et le contrôle de la TB.
RESUMO
On 7 February 2021, a catastrophic mass flow descended the Ronti Gad, Rishiganga, and Dhauliganga valleys in Chamoli, Uttarakhand, India, causing widespread devastation and severely damaging two hydropower projects. More than 200 people were killed or are missing. Our analysis of satellite imagery, seismic records, numerical model results, and eyewitness videos reveals that ~27 × 106 cubic meters of rock and glacier ice collapsed from the steep north face of Ronti Peak. The rock and ice avalanche rapidly transformed into an extraordinarily large and mobile debris flow that transported boulders greater than 20 meters in diameter and scoured the valley walls up to 220 meters above the valley floor. The intersection of the hazard cascade with downvalley infrastructure resulted in a disaster, which highlights key questions about adequate monitoring and sustainable development in the Himalaya as well as other remote, high-mountain environments.