Caracterización de la estadificación molecular en carcinoma de colon. Correlación clínico-histológica

[spa] ANTECEDENTES: El tratamiento del carcinoma colorectal (CCR) en estadios I-II es quirúrgico, aunque un 25% de pacientes pueden recidivar. El estadio ganglionar es un factor pronóstico independiente y determina el tratamiento quimioterápico. El estadiaje ganglionar histológico (pN) se realiza con tinción de hematoxilina-eosina (HE), método poco sensible para detectar pacientes con riesgo de recidiva. Las técnicas moleculares detectan células tumorales en el 25-50% de los ganglios linfáticos (GLs) de CCR que se han diagnosticado como negativos por HE, las cuales se asocian en el CCR precoz a mayor riesgo de recidiva y peor supervivencia. Sin embargo, el diagnóstico molecular es complejo y costoso, impidiendo su uso en la práctica clínica. OBJETIVOS, ESTUDIOS REALIZADOS Y RESULTADOS OBTENIDOS: El primer estudio que compone la tesis doctoral es multicéntrico y prospectivo. Tiene como objetivo determinar la relación entre la carga tumoral molecular en GLs y los factores de riesgo convencionales en pacientes con cáncer de colon en estadios I-II. Se obtuvieron 1940 GLs de 149 pacientes con cáncer de colon con estadio histológico pN0. Se cuantificó la cantidad de ARNm mensajero (ARNm) de citoqueratina 19 (CK19) en los GLs mediante la técnica Reverse Transcription Loop-Mediated Isothermal Amplification (RT-LAMP) denominada One-Step Nucleic Acid Amplification. Se definió la carga tumoral total (CTT) de cada paciente como la suma de todas las copias de ARNm de CK19/μL de cada GL positivo por colectomía. Se obtuvo una mediana de 15 GLs por caso (RIC 12;20). La positividad molecular se correlacionó con la presencia de áreas de alto grado (p <0,01), histología mucinosa/anillo de sello (p = 0,017), sexo masculino (p = 0,02), número GLs aislados (p = 0,012) y el peso total de GLs por caso (p < 0,01). La CTT se relacionó con el estadio pT (p = 0,01) y tamaño tumoral (p <0,01) en los tumores de bajo grado. El estudio de regresión logística multivariante mostró una correlación independiente de positividad molecular con el género, grado tumoral y número de GLs en fresco [AUC = 0,71 (IC del 95% = 0,62 a 0,79)]. El objetivo del segundo estudio es evaluar el impacto del tatuaje endoscópico prequirúrgico en la detección molecular de carga tumoral en GLs de neoplasias de colon en estadios iniciales. Métodos: Se trata de un estudio de cohorte prospectivo basado en una población de cribado de CCR en un hospital universitario terciario. Se evaluaron los GLs de colectomías con y sin tatuaje endoscópico preoperatorio mediante dos métodos, HE y RT-LAMP. Se comparó la cantidad de la carga tumoral y los valores de GLs obtenidos entre especímenes tatuados y no tatuados. Resultados: Se evaluaron mediante HE y RT-LAMP 936 GLs obtenidos de 71 colectomías que contenían carcinomas precoces y adenomas endoscópicamente irresecables (8 pT0, 17 pTis, 27 pT1, 19 pT2); 47 de 71 casos (66,2%) estaban tatuados. La positividad molecular en GLs se correlacionó con la presencia de tatuaje ganglionar [p <0,001; odds ratio 3.1 (95% IC 1.7 a 5.5)]. Se obtuvo un número significativamente mayor de GLs en especímenes tatuados en comparación con los no tatuados (mediana 17 GLs vs. 14,5 GLs; p = 0,019). CONCLUSIONES: Los resultados de los estudios de la presente tesis doctoral muestran que la detección de ARNm de CK19 en ganglios linfáticos se correlaciona con factores de alto riesgo clásicos en pacientes con cáncer de colon en estadio I-II. La CTT es una medida cuantitativa y objetiva que puede contribuir a una mejor estadificación de pacientes con cáncer de colon precoz. Asimismo, el tatuaje endoscópico permite la detección de los ganglios linfáticos más proclives a albergar células tumorales y aumenta el número de ganglios linfáticos aislados.[emg] Stage I–II colorectal cancer patients are surgically treated although up to 25 % will recur from disease. Molecular tumour detection in LN of early-stage patients is associated with an increased risk of disease recurrence and poor survival. The first study is a prospective multicentre study aimed to determine the relationship between LN molecular tumour burden and conventional high-risk factors in stage I–II colon cancer patients. A total of 1940 LN from 149 pN0 colon cancer patients were analysed for the amount of tumour CK19 mRNA with the quantitative OSNA molecular assay. Patient’s total tumour load (TTL) resulted from the sum of all CK19 mRNA tumour copies/μL of each positive LN from the colectomy specimen. A median of 15 LN were procured per case. Molecular positivity correlated with high-grade, mucinous/signet ring type, male gender, number of collected LN and total LN weight per case (p≤0.02). The TTL was related to pT stage and tumour size in low-grade tumours (p≤0.01). Multivariate logistic regression showed independent correlation of molecular positivity with gender, tumour grade and number of fresh LN (AUC=0.71). The second study aimed to evaluate the impact of presurgical endoscopic tattooing in early colon neoplasms (i.e. amount of tumour burden in LNs and LN yields). A prospective cohort study from a CRC screening-based population was performed. LNs from colectomies with and without preoperative endoscopic tattooing were assessed by HE and OSNA. HE and OSNA analyses of 936 LNs were performed from 71 colectomies containing early carcinomas and endoscopically unresectable adenomas; 47/71 cases were tattooed. Molecular positivity correlated with the presence of tattoo in LN (p<0.001; OR 3.1). A significantly higher number of LNs were obtained in tattooed specimens (median 17 LN vs. 14.5 LN; p=0.019). In conclusion, lymph node CK19 mRNA detection correlates with classical high-risk factors in stage I–II colon cancer patients. TTL is a quantitative and objective measure that may help to better stage early colon cancer patients. Additionally, endoscopic tattooing enables the analysis of those LNs most prone to harbour tumour cells and improves the number of LN harvested

Budget Impact Analysis of Molecular Lymph Node Staging Versus Conventional Histopathology Staging in Colorectal Carcinoma

Background: The presence of lymph node (LN) metastasis is a critical prognostic factor in colorectal cancer (CRC) patients and is also an indicator for adjuvant chemotherapy. The gold standard (GS) technique for LN diagnosis and staging is based on the analysis of haematoxylin and eosin (H&E)-stained slides, but its sensitivity is low. As a result, patients may not be properly diagnosed and some may have local recurrence or distant metastases after curative-intent surgery. Many of these diagnostic and treatment problems could be avoided if the one-step nucleic acid amplification assay (OSNA) was used rather than the GS technique. OSNA is a fast, automated, standardised, highly sensitive, quantitative technique for detecting LN metastases. Objectives: The aim of this study was to assess the budget impact of introducing OSNA LN analysis in early-stage CRC patients in the Spanish National Health System (NHS). Methods: A budget impact analysis comparing two scenarios (GS vs. OSNA) was developed within the Spanish NHS framework over a 3-year time frame (2017-2019). The patient population consisted of newly diagnosed CRC patients undergoing surgical treatment, and the following costs were included: initial surgery, pathological diagnosis, staging, follow-up expenses, systemic treatment and surgery after recurrence. One- and two-way sensitivity analyses were performed. Results: Using OSNA instead of the GS would have saved 1,509,182, 6,854,501 and 10,814,082 during the first, second and third years of the analysis, respectively, because patients incur additional costs in later years, leading to savings of more than 19 million for the NHS over the 3-year time horizon. Conclusions: Introducing OSNA in CRC LN analysis may represent not only an economic benefit for the NHS but also a clinical benefit for CRC patients since a more accurate staging could be performed, thus avoiding unnecessary treatments

Cognitive decline in amyotrophic lateral sclerosis: Neuropathological substrate and genetic determinants

Cognitive impairment and behavioral changes in amyotrophic lateral sclerosis (ALS) are now recognized as part of the disease. Whether it is solely related to the extent of TDP-43 pathology is currently unclear. We aim to evaluate the influence of age, genetics, neuropathological features, and concomitant pathologies on cognitive impairment in ALS patients. We analyzed a postmortem series of 104 ALS patients and retrospectively reviewed clinical and neuropathological data. We assessed the burden and extent of concomitant pathologies, the role of APOE ε4 and mutations, and correlated these findings with cognitive status. We performed a logistic regression model to identify which pathologies are related to cognitive impairment. Cognitive decline was recorded in 38.5% of the subjects. Neuropathological features of frontotemporal lobar degeneration (FTLD) were found in 32.7%, explaining most, but not all, cases with cognitive impairment. Extent of TDP-43 pathology and the presence of hippocampal sclerosis were associated with cognitive impairment. Mutation carriers presented a higher burden of TDP-43 pathology and FTLD more frequently than sporadic cases. Most cases (89.4%) presented some degree of concomitant pathologies. The presence of concomitant pathologies was associated with older age at death. FTLD, but also Alzheimer's disease, were the predominant underlying pathologies explaining the cognitive impairment in ALS patients. In sum, FTLD explained the presence of cognitive decline in most but not all ALS cases, while other non-FTLD related findings can influence the cognitive status, particularly in older age groups

Epigenetic loss of RNA‑methyltransferase NSUN5 in glioma targets ribosomes to drive stress adaptive translational program

Tumors have aberrant proteomes that often do not match their corresponding transcriptome profiles. One possible cause of this discrepancy is the existence of aberrant RNA modification landscapes in the so-called epitranscriptome. Here, we report that human glioma cells undergo DNA methylation-associated epigenetic silencing of NSUN5, a candidate RNA methyltransferase for 5-methylcytosine. In this setting, NSUN5 exhibits tumor-suppressor characteristics in vivo glioma models. We also found that NSUN5 loss generates an unmethylated status at the C3782 position of 28S rRNA that drives an overall depletion of protein synthesis, and leads to the emergence of an adaptive translational program for survival under conditions of cellular stress. Interestingly, NSUN5 epigenetic inactivation also renders these gliomas sensitive to bioactivatable substrates of the stress-related enzyme NQO1. Most importantly, NSUN5 epigenetic inactivation is a hallmark of glioma patients with long-term survival for this otherwise devastating disease

Epigenetic loss of RNA‑methyltransferase NSUN5 in glioma targets ribosomes to drive stress adaptive translational program

Tumors have aberrant proteomes that often do not match their corresponding transcriptome profiles. One possible cause of this discrepancy is the existence of aberrant RNA modification landscapes in the so-called epitranscriptome. Here, we report that human glioma cells undergo DNA methylation-associated epigenetic silencing of NSUN5, a candidate RNA methyltransferase for 5-methylcytosine. In this setting, NSUN5 exhibits tumor-suppressor characteristics in vivo glioma models. We also found that NSUN5 loss generates an unmethylated status at the C3782 position of 28S rRNA that drives an overall depletion of protein synthesis, and leads to the emergence of an adaptive translational program for survival under conditions of cellular stress. Interestingly, NSUN5 epigenetic inactivation also renders these gliomas sensitive to bioactivatable substrates of the stress-related enzyme NQO1. Most importantly, NSUN5 epigenetic inactivation is a hallmark of glioma patients with long-term survival for this otherwise devastating disease

Epigenetic loss of RNA‑methyltransferase NSUN5 in glioma targets ribosomes to drive stress adaptive translational program

Tumors have aberrant proteomes that often do not match their corresponding transcriptome profiles. One possible cause of this discrepancy is the existence of aberrant RNA modification landscapes in the so-called epitranscriptome. Here, we report that human glioma cells undergo DNA methylation-associated epigenetic silencing of NSUN5, a candidate RNA methyltransferase for 5-methylcytosine. In this setting, NSUN5 exhibits tumor-suppressor characteristics in vivo glioma models. We also found that NSUN5 loss generates an unmethylated status at the C3782 position of 28S rRNA that drives an overall depletion of protein synthesis, and leads to the emergence of an adaptive translational program for survival under conditions of cellular stress. Interestingly, NSUN5 epigenetic inactivation also renders these gliomas sensitive to bioactivatable substrates of the stress-related enzyme NQO1. Most importantly, NSUN5 epigenetic inactivation is a hallmark of glioma patients with long-term survival for this otherwise devastating disease

Epigenetic loss of RNA‑methyltransferase NSUN5 in glioma targets ribosomes to drive stress adaptive translational program

Tumors have aberrant proteomes that often do not match their corresponding transcriptome profiles. One possible cause of this discrepancy is the existence of aberrant RNA modification landscapes in the so-called epitranscriptome. Here, we report that human glioma cells undergo DNA methylation-associated epigenetic silencing of NSUN5, a candidate RNA methyltransferase for 5-methylcytosine. In this setting, NSUN5 exhibits tumor-suppressor characteristics in vivo glioma models. We also found that NSUN5 loss generates an unmethylated status at the C3782 position of 28S rRNA that drives an overall depletion of protein synthesis, and leads to the emergence of an adaptive translational program for survival under conditions of cellular stress. Interestingly, NSUN5 epigenetic inactivation also renders these gliomas sensitive to bioactivatable substrates of the stress-related enzyme NQO1. Most importantly, NSUN5 epigenetic inactivation is a hallmark of glioma patients with long-term survival for this otherwise devastating disease

Epigenetic loss of RNA‑methyltransferase NSUN5 in glioma targets ribosomes to drive stress adaptive translational program

Tumors have aberrant proteomes that often do not match their corresponding transcriptome profiles. One possible cause of this discrepancy is the existence of aberrant RNA modification landscapes in the so-called epitranscriptome. Here, we report that human glioma cells undergo DNA methylation-associated epigenetic silencing of NSUN5, a candidate RNA methyltransferase for 5-methylcytosine. In this setting, NSUN5 exhibits tumor-suppressor characteristics in vivo glioma models. We also found that NSUN5 loss generates an unmethylated status at the C3782 position of 28S rRNA that drives an overall depletion of protein synthesis, and leads to the emergence of an adaptive translational program for survival under conditions of cellular stress. Interestingly, NSUN5 epigenetic inactivation also renders these gliomas sensitive to bioactivatable substrates of the stress-related enzyme NQO1. Most importantly, NSUN5 epigenetic inactivation is a hallmark of glioma patients with long-term survival for this otherwise devastating disease