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.

Cytokeratin expression in gastrointestinal stromal tumor: a clinicopathologic and immunohistochemical study of 687 cases.

Gastrointestinal stromal tumor is the most common clinically significant mesenchymal neoplasm of the gastrointestinal tract. The expression of the intermediate filament cytokeratin in gastrointestinal stromal tumor is not frequently reported in the literature. The aim of this study was to investigate the immunohistochemical expression of several types of cytokeratin in a large number of cases (n=687), including a pan-cytokeratin marker (AE1/AE3 cocktail antibodies), high-molecular weight cytokeratins (34ßE12 antibody), and individual cytokeratins 8 (35ßH11 and CAM5.

Estrogen and progesterone receptor testing in breast carcinoma: concordance of results between local and reference laboratories in Brazil.

Context And Objective: Breast cancer accounts for approximately one quarter of all cancers in females. Estrogen and progesterone receptor testing has become an essential part of the clinical evaluation of breast carcinoma patients, and accurate results are critical in identifying patients who may benefit from hormone therapy. The present study had the aim of investigating the concordance of the results from hormone receptor tests between a reference laboratory and local (or community) laboratories in Brazil.

HER2 testing in breast carcinoma: very low concordance rate between reference and local laboratories in Brazil.

Breast cancer accounts for approximately one quarter of all cancers in females. HER2 gene amplification or HER2 protein overexpression, detected in about 20% of breast carcinomas, predicts a more aggressive clinical course and determines eligibility for targeted therapy with trastuzumab. HER2 testing has become an essential part of the clinical evaluation of all breast carcinoma patients, and accurate HER2 results are critical in identifying patients who may be benefited from targeted therapy.

Prognostic relevance of KIT and PDGFRA mutations in gastrointestinal stromal tumors.

Background: Prediction of biological behavior is crucial for selection of new therapeutic modalities in GIST. Here, we aimed to assess whether KIT and PDGFRA mutations have survival impact in gastrointestinal stromal tumors (GIST).

Patients And Methods: Fifty-five Brazilian patients with completely resected GIST were examined for KIT and PDGFRA mutations.

DOG1 for the diagnosis of gastrointestinal stromal tumor (GIST): Comparison between 2 different antibodies.

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. Discovered on GIST-1 (DOG1) is a recently described protein expressed in GISTs irrespective of mutation status. The aim of this study was to investigate the immunohistochemical expression of DOG1 using 2 different monoclonal antibodies (DOG1.

Imatinib treatment for gastrointestinal stromal tumour (GIST).

Gastrointestinal stromal tumour (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. GISTs are believed to originate from intersticial cells of Cajal (the pacemaker cells of the gastrointestinal tract) or related stem cells, and are characterized by KIT or platelet-derived growth factor receptor alpha (PDGFRA) activating mutations. The use of imatinib has revolutionized the management of GIST and altered its natural history, substantially improving survival time and delaying disease progression in many patients.

Androgen receptor expression in gastrointestinal stromal tumor.

The aim of this study was to evaluate the expression of estrogen, progesterone, and androgen receptors in a large series of gastrointestinal stromal tumors. Clinical and pathologic data were reviewed in 427 cases of gastrointestinal stromal tumor and the expression of such hormone receptors was investigated by immunohistochemistry using tissue microarray technique. All tumors were negative for estrogen receptor expression.

HER-2 status in gastrointestinal stromal tumor.

Human epidermal growth factor receptor-2 (HER-2) encodes for the transmembrane glycoprotein HER-2 that is involved in activation of intracellular signal transduction pathways that control cell growth and differentiation. HER-2 is overexpressed in approximately 20% of patients with breast cancer and has been associated with poorer prognosis. Since 1998, the anti-HER-2 antibody trastuzumab has been used for the treatment of patients with HER-2-positive breast cancers.

Gastrointestinal stromal tumor in Brazil: clinicopathology, immunohistochemistry, and molecular genetics of 513 cases.

The aim of the present study was to evaluate the clinicopathological, immunohistochemical, and molecular genetic features of gastrointestinal stromal tumors in Brazil and compare them with cases from other countries. Five hundred and thirteen cases were retrospectively analyzed. HE-stained sections and clinical information were reviewed and the immunohistochemical expression of CD117, CD34, smooth-muscle actin, S-100 protein, desmin, CD44v3 adhesion molecule, p53 protein, epidermal growth factor receptor, and Ki-67 antigen was studied using tissue microarrays.

EGFR and gastrointestinal stromal tumor: an immunohistochemical and FISH study of 82 cases.

Gastrointestinal stromal tumor is the most common mesenchymal neoplasm of the gastrointestinal tract. Mutually exclusive KIT or platelet-derived growth factor receptor-alpha mutations are key events in gastrointestinal stromal tumor pathogenesis, and specific treatment targeting KIT/platelet-derived growth factor receptor-alpha activation is available. Epidermal growth factor receptor plays an important role in cancer biology and also constitutes a promising molecular target of therapy.

Emperipolesis in a case of B-cell lymphoma: a rare phenomenon outside of Rosai-Dorfman disease.

We describe a case of a diffuse large B-cell lymphoma with extensive emperipolesis phenomenon. Light microscopy revealed numerous CD68-positive/S-100-negative histiocytes containing viable neoplastic hematopoietic cells in their cytoplasm. Electron microscopy confirmed these findings.