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Abstract Background Tobacco use is one of the main risk factors for Lung Cancer (LC) development. However, about 10–20% of those diagnosed with the disease are never-smokers. For Non-Small Cell Lung Cancer (NSCLC) there are clear differences in both the clinical presentation and the tumor genomic profiles between smokers and never-smokers. For example, the Lung Adenocarcinoma (LUAD) histological subtype in never-smokers is predominately found in young women of European, North American, and Asian descent. While the clinical presentation and tumor genomic profiles of smokers have been widely examined, never-smokers are usually underrepresented, especially those of a Latin American (LA) background. In this work, we characterize, for the first time, the difference in the genomic profiles between smokers and never-smokers LC patients from Chile. Methods We conduct a comparison by smoking status in the frequencies of genomic alterations (GAs) including somatic mutations and structural variants (fusions) in a total of 10 clinically relevant genes, including the eight most common actionable genes for LC (EGFR, KRAS, ALK, MET, BRAF, RET, ERBB2, and ROS1) and two established driver genes for malignancies other than LC (PIK3CA and MAP2K1). Study participants were grouped as either smokers (current and former, n = 473) or never-smokers (n = 200) according to self-report tobacco use at enrollment. Results Our findings indicate a higher overall GA frequency for never-smokers compared to smokers (58 vs. 45.7, p-value

Abstract 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. Demographics, clinicopathological characteristics and therapeutic outcomes were collected locally and analyzed in a centralized manner. Results A total of 135 patients were included. Median age at diagnosis was 53 years old (19–84), 53.3% (n = 72) of patients were female and 87.4% had an ECOG performance score ranging from 0–1. A total of 47 patients (34.8%) had metastatic disease at diagnosis. Concurrent myasthenia gravis occurred in 21.5% of patients. Surgery was performed in 74 patients (54.8%), comprising 27 (20%) tumorectomies and 47 (34.8%) thymectomies. According to the Masaoka‐Koga system, overall survival (OS) at five‐years was 73.4%, 63.8% and 51%, at stages I–II, III–IVA and IVB, respectively (p = 0.005). Furthermore, patients with low lactate dehydrogenase (LDH) (≤373 IU/L) at baseline and myasthenia gravis concurrence showed significantly better OS (p = 0.001 and p = 0.008, respectively). In multivariate analysis, high LDH levels (HR 2.8 [95% confidence interval [CI]: 1.1–7.8]; p = 0.036) at baseline and not performing a surgical resection (HR 4.1 [95% CI: 1.3–12.7]; p = 0.016) were significantly associated with increased risk of death. Conclusions Our data provides the largest insight into the clinical characteristics and outcomes of patients with thymomas in Latin America. Survival in patients with thymomas continues to be very favorable, especially when subjected to adequate local control.

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. The Cox model was applied to determine the variables associated with survival. A random forest tree model was built to predict the response to first‐line chemotherapy among Latin American patients. Results The median age was 61.1 years (SD 10.6 years), 191 (63.2%) were men, 65.9% were ever smokers, and 38.7% had previous exposure to asbestos. A total of 237 (78.5%) had epithelioid tumors, and 188 (62.3%) and 114 (37.7%) cases had stage III or IV MPM, respectively. A total of 49 patients (16.2%) underwent pleurectomy, 57 (18.9%) received radiotherapy, and 279 patients received first‐line platinum‐based chemotherapy. The overall response rate to first‐line chemotherapy was 40.4%, progression‐free survival to first‐line treatment was 5.7 months (95% CI 4.9–6.5), and 63 (20.8%) patients had pemetrexed maintenance. The median overall survival was 16.8 months (95% CI 13.0–20.5), and multivariate analysis found that stage (P = 0.013), and pleurodesis (P = 0.048), were independent prognostic factors for first‐line overall survival. The model to predict response to first‐line chemotherapy obtained a 0.98 area under the curve, a sensitivity of 93%, and a specificity of 95% for detecting responders and non‐responders. Conclusion This study identifies factors associated with clinical benefit from chemotherapy among advanced MPM Latin American patients, emphasizing the impact of histology and the clinical benefit of chemotherapy on outcomes.

Objectives: 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 EGFR 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.Materials and Methods:EGFR driver mutation data were collected from a large Brazilian LA cohort covering an 8-year period of molecular testing in a single institution. Tests were performed using three distinct methods, and demographic and histopathological data were analyzed. For a subset of patients, driver mutations in KRAS, NRAS, and BRAF and gene fusions involving TKR genes (before TKI treatment) and EGFR T790M (after TKI treatment) were assessed.Results:EGFR mutations were detected in 25% of 1,316 LAs evaluated, with exon 19 deletions and exon 21 L858R TKI sensitizing mutations representing 72.5% of all mutations. Mutation rates were higher in women and non-smokers (p < 0.001). Next-generation sequencing was very sensitive, with a lower rate of inconclusive results compared with Sanger sequencing and pyrosequencing. EGFR/RAS/BRAF hotspot gene panels were applied in 495 LA cases and detected oncogenic mutations in 51.3% of samples, most frequently in EGFR (22.4%) and KRAS (26.9%). In subgroups of 36 and 35 patients, gene fusions were detected in 11.1% of tumors and EGFR T790M resistance mutations were detected in 59% of plasma samples from patients previously treated with TKI, respectively.Conclusion: This report provides the first comprehensive actionable alteration portrait of LA in Brazil. The high rate of actionable alterations in EGFR and other driver genes in LA reinforces the need to incorporate TKI guided by molecular diagnostics into clinical routines for patients in both public and private healthcare systems.

We report on a case of mediastinal granulocytic sarcoma with cardiac infiltration in a young man with no evidence of leukemia involving the bone marrow or peripheral blood. Diagnosis was accomplished by immuno-histochemistry with expressions of myeloperoxidase and CD99 antigens. The patient achieved clinical remission, but evolved with febrile neutropenia during chemotherapy and died. Although subclinical cardiac infiltrations are commonly found at autopsy in patients with acute non-lymphoblastic leukemia, only one case of involvement of the heart with granulocytic sarcoma in the absence of bone marrow disease has been published in the literature. A diagnosis of granulocytic sarcoma should not be excluded when the biopsy of the bone marrow does not show any evidence of leukemic infiltration.Relata-se o caso de um adulto jovem com sarcoma granulocítico (SG) mediastinal com infiltração cardíaca sem evidência de leucemia envolvendo medula óssea ou sangue periférico. O diagnóstico foi revelado pela imuno-histoquímica com positividade para mieloperoxidase e CD99. O paciente apresentou remissão clínica, porém evoluiu com neutropenia febril durante a quimioterapia e foi a óbito. Embora infiltrados cardíacos subclínicos sejam comumente detectados na autópsia em pacientes com leucemia aguda nãolinfoblástica, somente um caso de SG com envolvimento cardíaco na ausência de doença na medula óssea foi descrito na literatura. Um diagnóstico de SG não deve ser excluída quando a biópsia da medula óssea não mostrar nenhuma evidência de infiltração leucêmica.