Molecular Pathology in the New Age of Personalized Medicine

Personalized medicine is a new approach that allows the identification of patients that can benefit from targeted therapies because of the molecular characteristics of the tumors they present. The molecular profile of the tumor can be studied at the genomic (DNA), transcriptomic (RNA) or protein (protein) level. The next generation sequencing is a useful tool for the study of molecular profile from DNA/RNA. This tool requires molecular pathologists highly trained in pre-analytic processes, tumor area microdissection for tumor cell enrichment, methodology analysis and results. The in-depth study of molecular alterations in patients allows optimizing molecular diagnosis and selecting candidates for receive novel treatments against specific molecular targets. These patients are expected to benefit from multidisciplinary approach and learning. The aim of this chapter is to show the implications of molecular pathology in personalized medicine with an actual approach from the methodological limitations of formalin-fixed paraffin embedded (FFPE) tissues and their pre-analytical conditions

Clinical-pathological features and gene profile in colorectal cancer

El cáncer colorectal es el tercer cáncer más frecuente en hombres y el segundo más frecuente en mujeres, con una incidencia mundial aproximada de 1.2 millones de casos nuevos por año. El objetivo primario es estudiar la relación existente entre las características clínico-histológicas de individuos con cáncer colorectal y el estado mutacional de los codones 12 y 13 del gen KRAS (7 mutaciones validadas), con el fin de hallar un marcador histopatológico para los tumores mutados. El objetivo secundario es determinar cuantos pacientes tienen mutaciones adicionales en los codones 15 y 61 del gen KRAS y 600 del gen BRAF que podrían modificar el fenotipo tumoral. Fueron seleccionados 60 individuos con cáncer colorrectal (30 wild-type y 30 con mutaciones validadas en los codones 12 y 13 del gen KRAS). Se amplificaron y secuenciaron del gen KRAS los exones 2 y 3, y del gen BRAF el exón 15. La información recolectada se examinó mediante un análisis descriptivo, análisis univariado y/ó análisis multivariado según correspondiese. En conclusión, no se encontró relación entre las características clínico-histológicas de los tumores de individuos con diagnostico de cáncer colorectal y el estado mutacional de los codones 12 y 13 del gen KRAS. No hallamos un marcador histopatológico para los tumores mutados resulta interesante considerar el estudio del codón 600 del gen BRAF.Colorectal cancer is the third most frequent cancer in men and the second most frequent in women, with a worldwide incidence of approximately 1.2 million new cases per year. Our primary objective was to study the relationship between clinical and histological features of individuals with colorectal cancer and the mutational status of codons 12 and 13 of the KRAS gene (7 validated mutations), in order to find a histopathological marker to mutated tumors. The secondary objective was to determine how many patients had additional mutations in codons 15 and 61 of the KRAS gene, and codon 600 of the BRAF gene, which could modify the tumor phenotype. Sixty individuals with colorectal cancer (30 wild-type subjects and 30 with validated mutations in codons 12 and 13 of the KRAS gene) were selected. Exons 2 and 3 of the KRAS gene, and exon 15 of the BRAF gene were amplified and sequenced. The data collected were reviewed by a descriptive, univariate and/or multivariate analysis, as appropriate. In conclusion, no relation was found between clinical and histological features of individuals with colorectal cancer and their mutational status for codons 12 and 13 of the KRAS gene. This suggests that those easily available data do not allow predicting the response to anti-EGFR therapy. In patients with advanced colorectal adenocarcinomas and KRAS wild-type status, further study of codon 600 of the BRAF gene could be required.Fil: Perazzo, Florencia. Centro de Educación Médica e Investigaciones Clínicas; ArgentinaFil: Piaggio, Fernando. Centro de Educación Médica e Investigaciones Clínicas; ArgentinaFil: Krupitzki, Hugo Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Centro de Educación Médica e Investigaciones Clínicas; ArgentinaFil: Garcia, Alejandro Javier. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Centro de Educación Médica e Investigaciones Clínicas; ArgentinaFil: Avagnina, Alejandra. Centro de Educación Médica e Investigaciones Clínicas; ArgentinaFil: Elsner, Boris. Centro de Educación Médica e Investigaciones Clínicas; ArgentinaFil: Denninghoff, Valeria Cecilia. Centro de Educación Médica e Investigaciones Clínicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Correlation between PD-L1 expression (clones 28-8 and SP263) and histopathology in lung adenocarcinoma

Lung cancer is the leading cause of cancer-related death worldwide. Recent advances in the management of non-small cell carcinoma are focused on the discovery of targeted therapies and novel immunotherapy strategies for patients with advanced disease. Treatment with anti PD-(L)1 immune checkpoint inhibitors requires the development of predictive biomarkers to select those patients that can most benefit from these therapies. Several immunohistochemical biomarkers have been developed in different technological platforms. However, the most useful and accessible for the daily clinical practice need to be selected. The objective of this study was to compare PD-L1 expression by automated immunohistochemistry in lung adenocarcinoma (ADC) FFPE samples with clones 28-8 and SP263 performed with the BenchMark GX automated staining instrument. To further determine interobserver agreement between two pathologists, and to correlate the results with histologic and pathology variables. FFPE tissue from 40 samples obtained from patients with lung ADC were reviewed retrospectively. Among all studied specimens, 53% of samples presented <1% of positive tumor cells with the 28-8 clone and 50% had <1% of PD-L1 expression in tumor cells with the SP263 clone; PD-L1 expression between ≥1 and <5% was observed in 18% and 24%; ≥5 and <50% PD-L1 expression in 18% and 21%; and ≥50% PD-L1 expression in 11% and 5% of samples, respectively. Similar results between antibodies were observed in 84% of cases for each of the four PD-L1 cutoff groups (Pearson's score 0.90, p < 0.00001). The interobserver degree of agreement calculated with Kappa was 0.75 (95%CI: 0.57–0.93), z = 7.08; p < 0.001. Lepidic, acinar and mucinous patterns had predominantly <1% PD-L1 expression, and the solid pattern subtype had high levels of PD-L1 staining using both clones. PD-L1 expression in less than 1% of tumor cells was similar in stages I/II compared to III/IV. No significant differences were observed in PD-L1 staining and quantification pattern between IHC antibodies 28-8 and SP263.Fil: García, Alejandro. Centro de Educación Médica e Investigaciones Clínicas "Norberto Quirno"; ArgentinaFil: Recondo, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: Greco, Martín. Centro de Educación Médica e Investigaciones Clínicas "Norberto Quirno"; ArgentinaFil: de la Vega, Máximo. Centro de Educación Médica e Investigaciones Clínicas "Norberto Quirno"; ArgentinaFil: Perazzo, Florencia. Centro de Educación Médica e Investigaciones Clínicas "Norberto Quirno"; ArgentinaFil: Avagnina, Alejandra. Centro de Educación Médica e Investigaciones Clínicas "Norberto Quirno"; ArgentinaFil: Denninghoff, Valeria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; Argentin

Variable Number Tandem Repeats in the promoter region of prostacyclin synthase gene in choline deficient rats.

Weanling Sprague-Dawley rats were fed on a choline-deficient diet with hydrogenated vegetable oil and corn oil as lipids develop acute renal failure. Pathogenesis of the latter is controversial and an ischemic mechanism has been proposed. Arachidonic acid derivatives are involved in the regulation of vascular tonus. Vasospasm could be due to an increase in tromboxane A2-mediated vasoconstriction or to a decrease in prostacyclin-induced vasodilatation. Enzymes involved in the synthesis of both compounds are tromboxane A2- and prostacyclin-synthase respectively. The aim of this study was to identify the variable number tandem repeats (VNTR) in the promoter region of prostacyclin synthase gene and verify if there exists a relationship between the occurrence of VNTR in those choline-deficient rats which die because of acute renal failure and those which do not. We verified the presence of the VNTR in the prostacyclin synthase rat gene, but we did not find any difference in the molecular weight of the alleles between experimental and control rats. Renal reparation of the acute kidney injury due to choline deficiency in some rats is not related with differences in VNTR in the promoter region of the prostacyclin synthase gene. Weanling Sprague-Dawley rats fed a choline-deficient diet with hydrogenated vegetable oil and corn oil as lipids develop acute renal failure. Its pathogenesis is controversial. The ischemic mechanism has been proposed. Derivatives from arachidonic acid are involved in the regulation of vascular tone. Vasospasm could be due to an increase in vasoconstriction mediated by tromboxane A2 or a decrease in vasodilatation by prostacyclin. Enzymes involved in the synthesis of them are tromboxane A2 and prostacyclin synthase respectively. The aim of this study is to identify the variable number tandem repeats (VNTR) in the promoter region of prostacyclin synthase gene and verify if there exists a relationship between the VNTR and those rats which dye as a consequence of acute renal failure due to choline deficiency and those which do not die. The VNTR presence was detected by molecular methods. We verified the presence of the VNTR in the prostacyclin synthase rat gene. We did not find difference in the molecular weight of the alleles between experimental and control rats. Renal reparation of the acute kidney injury due to choline deficiency in Sprague-Dawley rats is not related with differences in prostacyclin synthase VNTR, in the promoter region of this gene.Fil: Denninghoff, Valeria Cecilia. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Ossani, Georgina Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; ArgentinaFil: Uceda, Ana Margarita. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; ArgentinaFil: Avagnina Iribarren, Maria Alejandra. Centro de Educaciones Médicas e Investigación Clínica "Norberto Quirno"; ArgentinaFil: Elsner, Boris. Centro de Educaciones Médicas e Investigación Clínica "Norberto Quirno"; ArgentinaFil: Monserrat, Alberto Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentin

Distribución de subtipos moleculares de adenocarcinoma de pulmón y resultados clínicos en un centro de Argentina

La prevalencia de alteraciones en oncogenes en adenocarcinoma de pulmón varía en nuestra región. El objetivo fue describir la prevalencia de mutaciones en KRAS, BRAF y EGFR y las translocaciones de ALK en pacientes con adenocarcinoma de pulmón y estudiar la supervivencia de acuerdo a subtipos moleculares. Se incluyeron pacientes con biopsias adecuadas para el estudio. Se evaluó el estado mutacional de KRAS, BRAF y EGFR por secuenciación con la técnica de Sanger. Las translocaciones de ALK se estudiaron por hibridación in situ por fluorescencia (FISH) e inmunohistoquimica (IHQ) contra ALK (clones D5F3 y 5A4). De 118 pacientes evaluados, se incluyeron 84 (72%) con análisis molecular completo. Se detectaron mutaciones de KRAS en 16 muestras (19%), EGFR en 11 (13%), y BRAF en 1 muestra (1%). Se detectaron rearreglos de ALK en 3 muestras (4%). La mediana de seguimiento de los pacientes fue de 42.4 [rango intercuatilo (RIC): 27.0-64.2] meses. Globalmente, la mediana de supervivencia en la población fue 10.3 [RIC: 5.6-20.2] meses y fue de 10.8 [RIC: 6.0 20.3] meses en pacientes sin alteraciones moleculares detectables. La mediana de supervivencia de los pacientes con mutación en KRAS fue de 9.6 [RIC: 3.7-16.1] meses (HR: 1.08; p = 0.82) y 32.5 [RIC: 19.6-38.4] meses en el grupo con rearreglos de ALK o mutaciones en EGFR tratados con inhibidores de tirosina quinasa (HR: 0.27; p = 0.03). En conclusión, la prevalencia de alteraciones moleculares en nuestra población fue similar a otros países occidentales.The prevalence of relevant oncogenic drivers in lung adenocarcinoma varies in our region and data on clinical outcomes is scarce. The objective of the study was to describe the prevalence of KRAS, BRAF and EGFR mutations and ALK translocations in patients with advanced lung adenocarcinoma, and to depict the clinical outcome according to treatment strategies. Patients with adequate tumor biopsy sampling were included. KRAS, BRAF and EGFR mutations were studied by Sanger sequencing. ALK translocations were studied by fluorescent in situ hybridization (FISH) and immunohistochemistry (IH) with antibodies against ALK with clones D5F3 and 5A4. Informed consent was signed by 118 patients and 84 (72%) with complete molecular analysis were included. KRAS mutations were detected in 16 samples (19%), EGFR in 11 (13%), 9 of them conferring sensitivity to EGFR inhibitors, and BRAF mutations in 1 (1%). ALK translocations were detected in 3 samples (4%). Median follow-up was 42.4 [interquartile range (IQR): 27.0-64.2] months. Globally, median overall survival was 10.3 [IQR: 5.6-20.2] months. Median survival was 10.8 [IQR: 6.0-20.3] months in the group of patients without detectable molecular alteration, 9.6 [IQR: 3.7-16.1] months in KRAS mutant population (HR: 1.08; p = 0.82) and 32.5 [IQR: 19.6-38.4] months in patients with ALK translocations or sensitizing EGFR mutated tumors treated with tyrosine kinase inhibitors (HR: 0.27; p = 0.03). In conclusion, the prevalence of molecular alterations and outcomes in our population is similar to that reported in other studies in Western countries.Fil: Recondo, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: Denninghoff, Valeria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: Cuello, Maria T.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: Lorente, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: Greco, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: de la Vega, Máximo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: Avagnina, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: Recondo, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; Argentin

Expresión inmunohistoquímica de p53 en individuos con liquen

Objetivo: Estimar el riesgo del potencial de malignización del liquen plano bucal analizando la expresión de la proteína p53. Materiales y metodos: Se realizó un diseño de cohorte de sujetos con diagnostico histopatológico de liquen. El desenlace fue el desarrollo de cáncer si/no. El total de individuos que cumplió con los criterios de inclusión/exclusión fue de 58. A los 58 sujetos se les realizó la determinación de p53. Resultados: Cuarenta y nueve individuos mostraron una expresión de p53 menor al 5% con una P>0,05% intrasujeto no transformado. En los 9 individuos transformados se observaron diferencias significativas entre la determinación pre y post de la proteína p53. El Riesgo Relativo fue de 188 con una significación estadística de P0.05 among subjects undergoing no transformation. In the 9 subjects undergoing malignant transformation, significant differences were observed between pre and post p53 expression. The relative risk was 188, with a statistical significance of p5% are associated with an increased risk of malignant transformation of this condition. Should our findings be proved in a larger series in the future, the clinical follow-up of these subjects could be modified. This would allow an early diagnosis of any disorder indicative of a potential malignant transformation.Fil: Muiño, A.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Adler, I.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Lence, A.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Harada, L.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Nieto, S.. Centro de Educaciones Médicas e Investigación Clínica "Norberto Quirno"; ArgentinaFil: Denninghoff, Valeria Cecilia. Centro de Educaciones Médicas e Investigación Clínica "Norberto Quirno"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Avagnina, A.. Centro de Educaciones Médicas e Investigación Clínica "Norberto Quirno"; ArgentinaFil: Keszler, A.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Lanfranchi, H.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Aguas, S.. Universidad de Buenos Aires. Facultad de Odontología; Argentin

Helicobacter Pylori Infection of Lingual Dorsum: Risk of Gastric Infection Helicobacter Pylori

The role of Helicobacter pylori in the oral cavity has been researched/studied by our study group for the last 28 years. At that time, there wasn’t a clinical entity that included Burning, Lingual Papillary Hypertrophy and Halitosis (BHH) together. However, the patients who presented this condition did not find an effective response to their demand. In some cases, a therapeutic diagnosis of Chronic Candidiasis was made in relation to Lingual Papillary Hypertrophy and they were referred to Periodontics Services for their Chronic Halitosis for evaluation and treatment. Many of these patients did not resolve their clinical symptoms, in their subsequent check-ups. The burning of the mouth was usually diagnosed as Burning Mouth Syndrome. A considerable percentage (60%) of these patients reported suffering from chronic gastric discomfort without receiving treatment, because when they consulted with the physician or with the gastroenterologist, their symptoms were associated with stress.Fil: Muiños, Antonio Luis. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Harada, L.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Diaz, M. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Labbrozzi, M.. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Turon, Pablo Javier. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Lence, Adriana Nora. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Aguas, Silvia Cristina. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Denninghoff, Valeria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Adler, Lidia Isabel. Universidad de Buenos Aires. Facultad de Odontología; Argentin

Circulating epithelial cell as viral infection and tissue origin marker in patients with severe COVID-19

Liquid biopsy (LB) is a minimally invasive procedure that detects biomarkers in body fluids for real-time monitoring of patients. This study developed a new LB approach to analyze Circulating Epithelial Cells (CECs) in Intensive Care Unit (ICU) patients with severe COVID-19 and High-Exposure Negative Population to COVID-19 (HENPC) as the control group. The CECs were characterized by multispectral imaging flow cytometry, and an anti-SARS-CoV-2 Spike S1 protein (ProtS) antibody was used to detect infection. The results showed that CECs were present in most ICU patients (p = 0.0412), and their median number was significantly higher (p = 0.0004) than in controls. CEC clusters were only identified in patients, and high positive ProtS expression was observed in CECs from ICU patients compared to negative controls. In conclusion, LB could be a minimally invasive tool for detecting tissue damage caused by infectious agents and could provide real-time biological information about disease status and evolution. However, further validation in a larger population of patients is needed

Circulating Tumor Cells Enumeration from the Portal Vein for Risk Stratification in Early Pancreatic Cancer Patients

[Simple Summary] Effective biomarkers are needed to enable personalized medicine for pancreatic cancer patients. This study analyzes the prognostic value, in early pancreatic cancer, of circulating tumor cells and clusters from the central venous catheter and portal blood. Circulating tumor cells were isolated using an immunomagnetic selection and were detected by microscopy using immunocytochemistry staining. In conclusion, the circulating tumor cell number in portal blood identifies a death risk in patients with early pancreatic cancer.[Abstract] Background. Effective biomarkers are needed to enable personalized medicine for pancreatic cancer patients. This study analyzes the prognostic value, in early pancreatic cancer, of single circulating tumor cell (CTC) and CTC clusters from the central venous catheter (CVC) and portal blood (PV). Methods. In total, 7 mL of PV and CVC blood from 35 patients with early pancreatic cancer were analyzed. CTC were isolated using a positive immunomagnetic selection. The detection and identification of CTC were performed by immunocytochemistry (ICC) and were analyzed by Epi-fluorescence and confocal microscopy. Results. CTC and the clusters were detected both in PV and CVC. In both samples, the CTC number per cluster was higher in patients with grade three or poorly differentiated tumors (G3) than in patients with well (G1) or moderately (G2) differentiated. Patients with fewer than 185 CTC in PV exhibited a longer OS than patients with more than 185 CTC (24.5 vs. 10.0 months; p = 0.018). Similarly, patients with fewer than 15 clusters in PV showed a longer OS than patients with more than 15 clusters (19 vs. 10 months; p = 0.004). These significant correlations were not observed in CVC analyses. Conclusions. CTC presence in PV could be an important prognostic factor to predict poor prognosis in early pancreatic cancer. In addition, the number of clustered-CTC correlate to a tumor negative differentiation degree and, therefore, could be used as a diagnostic biomarker for pancreatic cancer.This research was funded by Carlos III Health Institute (Health Research Fund) grant number PI16/01465 and PI19/01821 (Co-financed by the European Regional Development Fund “A way to make Europe”)