Genomic Landscape of Primary Resistance to Osimertinib Among Hispanic Patients with EGFR-Mutant Non-Small Cell Lung Cancer (NSCLC): Results of an Observational Longitudinal Cohort Study.

Background: Epidermal growth factor receptor (EGFR) mutations (EGFRm) represent one of the most common genomic alterations identified among patients with non-small cell lung cancer (NSCLC). Several targeted agents for patients with EGFRm have been proven safe and effective, including the third-generation tyrosine kinase inhibitor (TKI) osimertinib. Nonetheless, some patients will present with or develop EGFR-TKI resistance mechanisms.

Mechanisms of Resistance to First-Line Osimertinib in Hispanic Patients With EGFR Mutant Non-Small Cell Lung Cancer (FRESTON-CLICaP).

Introduction: Osimertinib is a third generation EGFR-TKI inhibitor approved in the first-line setting for patients with advanced non-small cell lung cancer (NSCLC). Additionally, it represents the treatment of choice in patients who present with T790M mutations and evidence of relapse of the disease. Effectiveness and safety of this drug have been studied in multiple clinical trials and observational studies, however, information regarding outcomes among Hispanic patients treated with Osimertinib is scarce.

STK11 and KEAP1 mutations in non-small cell lung cancer patients: Descriptive analysis and prognostic value among Hispanics (STRIKE registry-CLICaP).

Background: Mutations in STK11 (STK11) and, frequently co-occurring, KEAP1 mutations (KEAP1) are associated with poor survival in metastatic Non-small Cell Lung Cancer (mNSCLC) patients treated with immunotherapy. However, there are limited data regarding the prognostic or predictive significance of these genomic alterations among Hispanics.

Methods: This retrospective study analyzed a cohort of Hispanic patients (N = 103) diagnosed with mNSCLC from the US and seven Latin American countries (LATAM) treated with immune checkpoint inhibitors (ICI) alone or in combination as first-line (Cohort A).

Concordance Analysis of ALK Gene Fusion Detection Methods in Patients with Non-Small-Cell Lung Cancer from Chile, Brazil, and Peru.

About 4% to 7% of the non-small-cell lung cancer patients have anaplastic lymphoma kinase (ALK) rearrangements, and specific targeted therapies improve patients' outcomes significantly. ALK gene fusions are detected by immunohistochemistry or fluorescent in situ hybridization as gold standards in South America. Next-generation sequencing-based assays are a reliable alternative, able to perform simultaneous detection of multiple events from a single sample.

Characteristics and outcomes of thymomas in Latin America: Results from over 10 years of experience (CLICaP-LATimus).

Background: Thymomas are a group of rare neoplasms of the anterior mediastinum. The objective of this study was to describe the demographics, clinical characteristics and treatment approaches in Latin America.

Methods: This was a retrospective multicenter cohort study including patients with histologically proven thymomas diagnosed between 1997 and 2018.

Mutational Signatures Driven by Epigenetic Determinants Enable the Stratification of Patients with Gastric Cancer for Therapeutic Intervention.

DNA mismatch repair deficiency (dMMR) is associated with the microsatellite instability (MSI) phenotype and leads to increased mutation load, which in turn may impact anti-tumor immune responses and treatment effectiveness. Various mutational signatures directly linked to dMMR have been described for primary cancers. To investigate which mutational signatures are associated with prognosis in gastric cancer, we performed a extraction of mutational signatures in a cohort of 787 patients.

Mutational Portrait of Lung Adenocarcinoma in Brazilian Patients: Past, Present, and Future of Molecular Profiling in the Clinic.

Approximately 60% of lung adenocarcinomas (LAs) carry mutations that can guide treatment with tyrosine-kinase inhibitors (TKI) and other targeted therapies. Data on activating mutations in and other tyrosine-kinase receptor (TKR) genes in highly admixed populations, such as that of Brazil, are scarce. In this study, we comprehensively analyzed the actionable alteration profile of LA in Brazilian patients.

The diffuse-type gastric cancer epidemiology enigma.

Background: Intestinal and diffuse gastric adenocarcinomas differ in clinical, epidemiological and molecular features. However, most of the concepts related to the intestinal-type are translated to gastric adenocarcinoma in general; thus, the peculiarities of the diffuse-type are underappreciated.

Results: Besides its growing importance, there are many gaps about the diffuse-type carcinogenesis and, as a result, its epidemiologic and pathogenetic features remain poorly understood.

Recommendations for detection, prioritization, and treatment of thoracic oncology patients during the COVID-19 pandemic: the THOCOoP cooperative group.

The world currently faces a pandemic due to SARS-CoV-2. Relevant information has emerged regarding the higher risk of poor outcomes in lung cancer patients. As such, lung cancer patients must be prioritized in terms of prevention, detection and treatment.

Real-World Prevalence of PD-L1 Expression Among Tumor Samples From Patients With Non-Small-Cell Lung Cancer.

Introduction: We analyzed the prevalence of non-small-cell lung cancer (NSCLC) with a programmed cell death ligand 1 (PD-L1) tumor proportion score (TPS) of ≥ 50% and compared the results with the existing data from clinical trials and databases from other countries.

Materials And Methods: The Latin American Cooperative Oncology Group and Grupo Brasileiro de Oncologia Torácica performed a retrospective, cross-sectional study from August 2017 to April 2018. PD-L1 expression was collected from pathology reports from 5 laboratories in Brazil.

ASTRIS: a global real-world study of osimertinib in >3000 patients with T790M positive non-small-cell lung cancer.

Osimertinib is a third-generation, irreversible, oral EGFR tyrosine kinase inhibitor. We report real-world effectiveness and safety data. T790M positive advanced non-small-cell lung cancer adults, who received ≥1 prior EGFR tyrosine kinase inhibitor, received osimertinib 80 mg daily.

APOBEC-mediated DNA alterations: A possible new mechanism of carcinogenesis in EBV-positive gastric cancer.

Mechanisms of viral oncogenesis are diverse and include the off-target activity of enzymes expressed by the infected cells, which evolved to target viral genomes for controlling their infection. Among these enzymes, the single-strand DNA editing capability of APOBECs represent a well-conserved viral infection response that can also cause untoward mutations in the host DNA. Here we show, after evaluating somatic single-nucleotide variations and transcriptome data in 240 gastric cancer samples, a positive correlation between APOBEC3s mRNA-expression and the APOBEC-mutation signature, both increased in EBV+ tumors.

Multigene Mutation Profiling and Clinical Characteristics of Small-Cell Lung Cancer in Never-Smokers vs. Heavy Smokers (Geno1.3-CLICaP).

Lung cancer is a heterogeneous disease. Presentation and prognosis are known to vary according to several factors, such as genetic and demographic characteristics. Small-cell lung cancer incidence is increasing in never-smokers.

Personalizing Precision Oncology Clinical Trials in Latin America: An Expert Panel on Challenges and Opportunities.

The participation of patients in precision oncology trials needs to fulfill molecular-based selection criteria. This strongly limits accrual, and as a consequence, screening successes have decreased, costs have increased, and fewer subjects are enrolled. To achieve narrowed targets, studies have been forced to be multicenter and multinational to reach a larger pool of candidates.

Identification of DNA mutations in gastric washes from gastric adenocarcinoma patients: Possible implications for liquid biopsies and patient follow-up.

Whereas cancer patients have benefited from liquid biopsies, the scenario for gastric adenocarcinoma (GAC) is still dismal. We used next-generation deep sequencing of TP53-a highly mutated and informative gene in GAC-to assess mutations in tumor biopsies, plasma (PL) and stomach fluids (gastric wash-GW). We evaluated their potential to reveal tumor-derived mutations, useful for monitoring mutational dynamics at diagnosis, progression and treatment.

Characteristics and long-term outcomes of advanced pleural mesothelioma in Latin America (MeSO-CLICaP).

Background: Malignant pleural mesothelioma (MPM) is an aggressive tumor, associated with poor prognosis. There is a lack of information about the clinical and pathological features related with survival in the Latin American population.

Methods: The MeSO-CLICaP registry identified 302 patients with advanced MPM diagnosed and treated between January 2008 and March 2016.

EGFR exon 20 insertion in lung adenocarcinomas among Hispanics (geno1.2-CLICaP).

Objectives: Contrasting other EGFR mutations (EGFRm) in lung adenocarcinomas, insertions in exon 20 (exon20ins) are generally associated with resistance to targeted therapy, limiting therapeutic options and impoverishing the prognosis compared to other EGFRm. We sought to extensively characterize exon20ins from a large cohort of lung adenocarcinomas in Hispanic patients.

Materials And Methods: This was a region-wide, observational longitudinal cohort study to evaluate characteristics and outcomes of patients with exon20ins in lung adenocarcinoma, based on a secondary analysis of electronic records from the Geno1.

Tissue-Associated Bacterial Alterations in Rectal Carcinoma Patients Revealed by 16S rRNA Community Profiling.

Sporadic and inflammatory forms of colorectal cancer (CRC) account for more than 80% of cases. Recent publications have shown mechanistic evidence for the involvement of gut bacteria in the development of both CRC-forms. Whereas, colon and rectal cancer have been routinely studied together as CRC, increasing evidence show these to be distinct diseases.

BRAZILIAN CONSENSUS FOR MULTIMODAL TREATMENT OF COLORECTAL LIVER METASTASES. MODULE 3: CONTROVERSIES AND UNRESECTABLE METASTASES.

In the last module of this consensus, controversial topics were discussed. Management of the disease after progression during first line chemotherapy was the first discussion. Next, the benefits of liver resection in the presence of extra-hepatic disease were debated, as soon as, the best sequence of treatment.

Involvement of nitric oxide on the pathogenesis of irinotecan-induced intestinal mucositis: role of cytokines on inducible nitric oxide synthase activation.

Purpose: Intestinal mucositis and the closely associated diarrhea are common costly side effects of irinotecan. Cytokine modulators, such as thalidomide and pentoxifylline, are found capable of attenuating intestinal mucositis progression. Nitric oxide (NO) seems to be a key mediator of the antineoplastic drug toxicity.

Interleukin-4 modulates the inflammatory response in ifosfamide-induced hemorrhagic cystitis.

We investigated whether interleukin-4 (IL-4) is present and capable of reducing inflammatory changes seen in ifosfamide-induced hemorrhagic cystitis. Male Swiss mice were treated with saline or ifosfamide alone or ifosfamide with the classical protocol with mesna and analyzed by changes in bladder wet weight (BWW), macroscopic and microscopic parameters, exudate, and hemoglobin quantification. In other groups, IL-4 was administered intraperitoneally 1 h before ifosfamide.