Detection of NTRK gene fusions in solid tumors: recommendations from a Latin American group of oncologists and pathologists.

NTRK gene fusions have been detected in more than 25 types of tumors and their prevalence is approximately 0.3% in solid tumors. This low prevalence makes identifying patients who could benefit from TRK inhibitors a considerable challenge. Furthermore, while numerous papers on the evaluation of NTRK fusion genes are available, not all countries have guidelines that are suitable for their setting, as is the case with Latin America. Therefore, a group of oncologists and pathologists from several countries in Latin America (Argentina, Chile, Ecuador, Mexico, Peru and Uruguay) met to discuss and reach consensus on how to identify patients with NTRK gene fusions in solid tumors. To do so, they developed a practical algorithm, considering their specific situation and limitations.

Synovial sarcoma with ossification and calcification with SS18 immunochemical expression and rearrangement by fluorescent in situ hybridization / Sarcoma sinovial con osificación y calcificación, con expresión de SS18 por inmunohistoquímica y reordenamiento de SS18 por hibridación in situ fluroescente

Synovial sarcoma is a soft tissue tumor of uncertain origin. Generally, it is a monophasic spindle cell neoplasm that can have glandular-like structures. Ossification and presence of calcification is a rare phenomenon with only a few reported cases. We present the case of a young male with a synovial sarcoma of the right foot. Histology revealed prominent deposits of tumoral osteoid and coarse calcifications. The diagnosis was confirmed by the expression of SS18 by immunohistochemistry and the demonstration of the rearrangement of the SS18 gene by fluorescent in situ hybridization. We reviewed the literature for synovial sarcoma with prominent ossification or calcification, and to the best of our knowledge, this is the first case with expression of SS18 by immunohistochemistry. The main differential diagnoses are osteosarcoma (both primary of bone and extraosseous) and sclerosing epithelioid fibrosarcoma.(AU)

El sarcoma sinovial (SS) es un tumor de partes blandas de origen incierto. Generalmente es una neoplasia monofásica de células fusiformes que puede tener estructuras de tipo glandular. La osificación y la presencia de calcificaciones es un fenómeno raro, con pocos casos reportados. A continuación presentamos el caso de un hombre joven con un sarcoma sinovial del pie derecho que en la histología mostró depósitos de osteoide tumoral y calcificaciones gruesas. El diagnóstico fue confirmado por la expresión de SS18 por inmunohistoquímica y la demostración del reordenamiento del gen SS18 por hibridación in situ fluorescente. Revisamos la literatura referente a sarcoma sinovial con osificación o calcificación prominente, y este es el primer caso con expresión de SS18 por inmunohistoquímica. Los principales diagnósticos diferenciales son con osteosarcoma (tanto primario de hueso como extraóseo) y fibrosarcoma epitelioide esclerosante (sclerosing epithelioid fibrosarcoma [SEF]).(AU)

Synovial sarcoma with ossification and calcification with SS18 immunochemical expression and rearrangement by fluorescent in situ hybridization.

Synovial sarcoma is a soft tissue tumor of uncertain origin. Generally, it is a monophasic spindle cell neoplasm that can have glandular-like structures. Ossification and presence of calcification is a rare phenomenon with only a few reported cases. We present the case of a young male with a synovial sarcoma of the right foot. Histology revealed prominent deposits of tumoral osteoid and coarse calcifications. The diagnosis was confirmed by the expression of SS18 by immunohistochemistry and the demonstration of the rearrangement of the SS18 gene by fluorescent in situ hybridization. We reviewed the literature for synovial sarcoma with prominent ossification or calcification, and to the best of our knowledge, this is the first case with expression of SS18 by immunohistochemistry. The main differential diagnoses are osteosarcoma (both primary of bone and extraosseous) and sclerosing epithelioid fibrosarcoma.

The Ring Study: an international comparison of PD-L1 diagnostic assays and their interpretation in non-small cell lung cancer, head and neck squamous cell cancer and urothelial cancer.

PD-L1 immunohistochemistry has been approved as a diagnostic assay for immunotherapy. However, an international comparison across multiple cancers is lacking. This study aimed to assess the performance of PD-L1 diagnostic assays in non-small cell lung cancer (NSCLC), head and neck squamous cell cancer (HNSCC) and urothelial cancer (UC). The excisional specimens of NSCLC, HNSCC and UC were assayed by Ventana SP263 and scored at three sites in each country, including Australia, Brazil, Korea, Mexico, Russia and Taiwan. All slides were rotated to two other sites for interobserver scoring. The same cohort of NSCLC was assessed with Dako 22C3 pharmDx PD-L1 for comparison. The PD-L1 immunopositivity was scored according to the approved PD-L1 scoring algorithms which were the percentage of PD-L1-expressing tumour cell (TC) and tumour proportion score (TPS) by Ventana SP263 and Dako 22C3 staining, respectively. In NSCLC, the comparison demonstrated the comparability of the SP263 and 22C3 assays (cut-off of 1%, κ=0.71; 25%, κ=0.75; 50%, κ=0.81). The interobserver comparisons showed moderate to almost perfect agreement for SP263 in TC staining at 25% cut-off (NSCLC, κ=0.72 to 0.86; HNSCC, κ=0.60 to 0.82; UC, κ=0.68 to 0.91) and at 50% cut-off for NSCLC (κ=0.64 to 0.90). Regarding the immune cell (IC) scoring in UC, there was a lower correlation (concordance correlation coefficient=0.10 to 0.68) and poor to substantial agreements at the 1%, 5%, 10% and 25% cut-offs (κ= -0.04 to 0.76). The interchangeability of SP263 and 22C3 in NSCLC might be acceptable, especially at the 50% cut-off. In HNSCC, the performance of SP263 is comparable across five countries. In UC, there was low concordance of IC staining, which may affect treatment decisions. Overall, the study showed the reliability and reproducibility of SP263 in NSCLC, HNSCC and UC.

Establishment of triple-negative breast cancer cells based on BMI: A novel model in the correlation between obesity and breast cancer.

Introduction: Obesity has been associated with an increased risk of biologically aggressive variants in breast cancer. Women with obesity often have tumors diagnosed at later stages of the disease, associated with a poorer prognosis and a different response to treatment. Human cell lines have been derived from specific subtypes of breast cancer and have served to define the cell physiology of corresponding breast cancer subtypes. However, there are no current cell lines for breast cancer specifically derived from patients with different BMIs. The availability of those breast cancer cell lines should allow to describe and unravel functional alterations linked to these comorbidities. Methods: Cell cultures were established from tumor explants. Once generated, the triple negative subtype in a patient with obesity and a patient with a normal BMI were chosen for comparison. For cellular characterization, the following assays were conducted: proliferation assays, chemo - sensitivity assays for doxorubicin and paclitaxel, wound healing motility assays, matrix invasion assays, breast cancer cell growth to estradiol by chronic exposure to leptin, induction of endothelial permeability and tumorigenic potential in athymic mice with normo - versus hypercaloric diets with an evaluation of the epithelium - mesenchymal transformation proteins. Results: Two different cell lines, were established from patients with breast cancer: DSG-BC1, with a BMI of 21.9 kg/m2 and DSG-BC2, with a BMI of 31.5 kg/m2. In vitro, these two cell lines show differential growth rates, motility, chemosensitivity, vascular permeability, response to leptin with an activation of the JAK2/STAT3/AKT signaling pathway. In vivo, they displayed distinct tumorigenic potential. In particular, DSG-BC2, presented higher tumorigenicity when implanted in mice fed with a hypercaloric diet. Discussion: To our knowledge, these primary cultures are the first in vitro representation of both breast cancer and obesity. DSG - BC2 presented a more aggressive in vivo and in vitro phenotype. These results support the hypothesis that breast cancer generated in an obese metabolic state may represent a contrasting variant within the same disease. This new model will allow both further comprehension, functional studies and the analysis of altered molecular mechanisms under the comorbidity of obesity and breast cancer.

Biological Landscape of Triple Negative Breast Cancers Expressing CTLA-4.

Patients with triple-negative breast cancer (TNBC) have a poor prognosis, partly because of the absence of targeted therapies. Recognition of the key role of immune responses against cancer has allowed the advent of immunotherapy, focused on the inhibition of negative immune checkpoints, such as CTLA-4. CTLA-4 is also expressed in some cancer cells, but its activity in tumor cells is not completely understood. Thus, the aim of the present work was to determine the biological landscape and functions of CTLA-4 expressed in TNBC cells through preclinical and in silico analysis. Exploration of CTLA-4 by immunohistochemistry in 50 TNBC tumors revealed membrane and cytoplasmic expression at different intensities. Preclinical experiments, using TNBC cell lines, showed that stimulation of CTLA-4 with CD80 enhances activation of the ERK1/2 signaling pathway, while CTLA-4 blockade by Ipilimumab induces the activation of AKT and reduces cell proliferation in vitro. We then developed an analytic pipeline to define the effects of CTLA-4 in available public data that allowed us to identify four distinct tumor clusters associated with CTLA-4 activation, which are characterized by enrichment of distinctive pathways associated with cell adhesion, MAPK signaling, TGF-ß, VEGF, TNF-α, drug metabolism, ion and amino acid transport, and KRAS signaling, among others. In addition, blockade of CTLA-4 induced increased secretion of IL-2 by tumor cells, suggesting that the receptor regulates cellular functions that may impact the immune microenvironment. This is relevant because a deep characterization of immune infiltrate, conducted using public data to estimate the abundancies of immune-cell types, showed that CTLA-4-activated-like tumors present a conditional immune state similar to an escape phenotype exploited by cancer cells. Finally, by interrogating transcriptional predictors of immunotherapy response, we defined that CTLA-4 activation correlates with high immune scores related to good clinical predicted responses to anti-CTLA-4 therapy. This work sheds new light on the roles of activated CLTA-4 in the tumor compartment and suggests an important interplay between tumor CLTA-4-activated portraits and immune-infiltrating cell populations.

[Metastatic oropharyngeal squamous cell carcinoma in cervical lymph nodes associated to HPV infection type 16 and 45; clinical, morphological and molecular study of two cases]. / Carcinoma epidermoide orofaríngeo metastásico en ganglios linfáticos cervicales asociado a los subtipos 16 y 45 del virus del papiloma humano (VPH). Estudio clínico, morfológico y molecular de dos casos.

Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma has been identified as a distinct entity within squamous cell carcinoma of the head and neck. In contrast to carcinomas associated with alcohol and/or tobacco, this subtype occurs at younger age, with frequent absence of classic risk factors, correlation with oral sexual habits, strong predilection for the palatial tonsils and the base of the tongue (lingual tonsils), basaloid or lymphoepithelial differentiation, higher degree of radiosensitivity, and overall better survival. We report two cases of lymph node, metastatic, poorly differentiated squamous cell carcinoma that were positive by immunohistochemistry for p16 with detection of HPV-16 and HPV-45 by PCR.

[National guidelines of diagnosis and treatment of the non-Hodgkin lymphoma]. / Guías nacionales de diagnóstico y tratamiento de linfoma no Hodgkin.

Non-Hodgkin lymphoma comprises a heterogeneous group of haematological malignancies, classified according to their clinic, anatomic-pathological features and, lately, to their molecular biomarkers. Despite the therapeutic advances, nearly half of the patients will die because of this disease. The new diagnostic tools have been the cornerstone to design recent therapy targets, which must be included in the current treatment guidelines of this sort of neoplasms by means of clinical trials and evidence-based medicine. In the face of poor diagnoses devices in most of the Mexican hospitals, we recommend the present diagnose stratification, and treatment guidelines for non-Hodgkin lymphoma, based on evidence. They include the latest and most innovative therapeutic approaches, as well as specific recommendations for hospitals with limited framework and therapy resources.

Sarcoma histiocítico. Estudio inmunohistoquímico de 6 casos / Immunohistochemical study of 6 cases of histocytic sarcoma

Introducción. El sarcoma histiocítco (SH) es una neoplasia poco frecuente con características morfológicas e inmunohistoquímicas de diferenciación histiocítica. Material y métodos. Presentamos 6 casos de SH. Se estudiaron cortes con hematoxilina y eosina y con inmunohistoquímica para CD45, CD163, CD68, lisozima, CD21, EMA, CD1a, S-100, CD20, Ki-67, HMB45 y CK AE1-3. Resultados. Cuatro pacientes fueron hombres y dos mujeres (edad promedio, 25,7 años; rango, 8 meses-64 años). Dos tumores se originaron en ganglios linfáticos, y los demás fueron extraganglionares (glándula parótida, meninges, tejidos blandos de tibia derecha y yeyuno). Los tumores estaban compuestos por células epitelioides medianas a grandes, pleomórficas, con abundante citoplasma eosinófilo, núcleos irregulares y nucléolos prominentes con áreas fusiformes focales y citofagocitosis. Las mitosis variaron con una media de 10 por campo de ×40. Un tumor presentó infiltrado inflamatorio prominente. Todos los tumores fueron positivos a CD45, CD163 y CD68 (KP1 y PGM-1), y 5 expresaron lisozima. Dos tumores fueron focal y débilmente positivos para S-100 y uno para CD1a; todos fueron negativos al CD 20, CD21, HMB45 y a CKAE1-3. Discusión. Para el diagnóstico de SH debe utilizarse CD45 además de dos antígenos asociados a macrófagos y ausencia de marcadores B, T, de melanoma y citoqueratinas(AU)

Introduction. Histiocytic sarcoma (HS) is a rare malignant neoplasm showing the morphologic and immunohistochemical features of histiocytic differentiation. Material and methods. We present 6 cases of HS diagnosed in 4 female and 2 male patients with ages ranging from 8 months to 64 years (medium age of 25.7 years). Sections were stained with hematoxylin and eosin and immunohistochemistry was performed using CD45, CD163, CD68, lysozyme, CD21, EMA, CD1a, S-100, CD20, Ki-67, HMB45 and CK AE1-3. Results. Two tumours arose from lymph nodes and 4 were extranodal (parotid gland, meninges, soft tissues and jejunum); all were composed of sheaths of medium to large pleomorphic epithelioid cells with abundant eosinophilic cytoplasm, irregular nuclei and prominent nucleoli with focal spindle cell features and cytophagocytosis. Mitotic features varied from case to case with a medium of 10 per 10 HPF. All tumours were positive for CD45, CD163 and CD68 (KP1 and PGM-1), 5 expressed lysozyme, 2 showed weak focal positivity for S-100 and 1 for CD1a. All were negative for CD 20, CD21, HMB45 and CK AE1-3. Discussion. It is important that the diagnosis of HS be based on immunohistochemical markers that should include CD45 plus two specific macrophage-associated antigens and the lack of the B-cell, T-cell, as well as cytokeratins and melanoma markers(AU)