RESUMEN
Mismatch repair (MMR)-deficient cancer evolves through the stepwise erosion of coding homopolymers in target genes. Curiously, the MMR genes MutS homolog 6 (MSH6) and MutS homolog 3 (MSH3) also contain coding homopolymers, and these are frequent mutational targets in MMR-deficient cancers. The impact of incremental MMR mutations on MMR-deficient cancer evolution is unknown. Here we show that microsatellite instability modulates DNA repair by toggling hypermutable mononucleotide homopolymer runs in MSH6 and MSH3 through stochastic frameshift switching. Spontaneous mutation and reversion modulate subclonal mutation rate, mutation bias and HLA and neoantigen diversity. Patient-derived organoids corroborate these observations and show that MMR homopolymer sequences drift back into reading frame in the absence of immune selection, suggesting a fitness cost of elevated mutation rates. Combined experimental and simulation studies demonstrate that subclonal immune selection favors incremental MMR mutations. Overall, our data demonstrate that MMR-deficient colorectal cancers fuel intratumor heterogeneity by adapting subclonal mutation rate and diversity to immune selection.
Asunto(s)
Neoplasias Colorrectales , Reparación de la Incompatibilidad de ADN , Inestabilidad de Microsatélites , Humanos , Neoplasias Colorrectales/genética , Reparación de la Incompatibilidad de ADN/genética , Proteínas de Unión al ADN/genética , Mutación , Proteína 3 Homóloga de MutS/genética , Tasa de Mutación , Mutación del Sistema de Lectura/genéticaRESUMEN
Gastric cancer is one of the most frequent causes of cancer-related deaths worldwide. Gastric atrophy (GA) and gastric intestinal metaplasia (IM) of the mucosa of the stomach have been found to increase the risk of gastric cancer and are considered precancerous lesions. Therefore, the early detection of GA and IM may have a valuable role in histopathological risk assessment. However, GA and IM are difficult to confirm endoscopically and, following the Sydney protocol, their diagnosis depends on the analysis of glandular morphology and on the identification of at least one well-defined goblet cell in a set of hematoxylin and eosin (H&E) -stained biopsy samples. To this end, the precise segmentation and classification of glands from the histological images plays an important role in the diagnostic confirmation of GA and IM. In this paper, we propose a digital pathology end-to-end workflow for gastric gland segmentation and classification for the analysis of gastric tissues. The proposed GAGL-VTNet, initially, extracts both global and local features combining multi-scale feature maps for the segmentation of glands and, subsequently, it adopts a vision transformer that exploits the visual dependences of the segmented glands towards their classification. For the analysis of gastric tissues, segmentation of mucosa is performed through an unsupervised model combining energy minimization and a U-Net model. Then, features of the segmented glands and mucosa are extracted and analyzed. To evaluate the efficiency of the proposed methodology we created the GAGL dataset consisting of 85 WSI, collected from 20 patients. The results demonstrate the existence of significant differences of the extracted features between normal, GA and IM cases. The proposed approach for gland and mucosa segmentation achieves an object dice score equal to 0.908 and 0.967 respectively, while for the classification of glands it achieves an F1 score equal to 0.94 showing great potential for the automated quantification and analysis of gastric biopsies.
Asunto(s)
Gastritis Atrófica , Infecciones por Helicobacter , Helicobacter pylori , Lesiones Precancerosas , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico por imagen , Neoplasias Gástricas/patología , Flujo de Trabajo , Gastritis Atrófica/diagnóstico por imagen , Gastritis Atrófica/patología , Mucosa Gástrica/diagnóstico por imagen , Mucosa Gástrica/patología , Atrofia/patología , Metaplasia/patología , Lesiones Precancerosas/diagnóstico por imagen , Lesiones Precancerosas/patología , Infecciones por Helicobacter/patologíaRESUMEN
Tertiary lymphoid structures (TLS) are ectopic aggregates of lymphoid cells in inflamed, infected, or tumoral tissues that are easily recognized on an H&E histology slide as discrete entities, distinct from lymphocytes. TLS are associated with improved cancer prognosis but there is no standardised method available to quantify their presence. Previous studies have used immunohistochemistry to determine the presence of specific cells as a marker of the TLS. This has now been proven to be an underestimate of the true number of TLS. Thus, we propose a methodology for the automated identification and quantification of TLS, based on H&E slides. We subsequently determined the mathematical criteria defining a TLS. TLS regions were identified through a deep convolutional neural network and segmentation of lymphocytes was performed through an ellipsoidal model. This methodology had a 92.87% specificity at 95% sensitivity, 88.79% specificity at 98% sensitivity and 84.32% specificity at 99% sensitivity level based on 144 TLS annotated H&E slides implying that the automated approach was able to reproduce the histopathologists' assessment with great accuracy. We showed that the minimum number of lymphocytes within TLS is 45 and the minimum TLS area is 6,245µm2. Furthermore, we have shown that the density of the lymphocytes is more than 3 times those outside of the TLS. The mean density and standard deviation of lymphocytes within a TLS area are 0.0128/µm2 and 0.0026/µm2 respectively compared to 0.004/µm2 and 0.001/µm2 in non-TLS regions. The proposed methodology shows great potential for automated identification and quantification of the TLS density on digital H&E slides.
Asunto(s)
Procesamiento de Imagen Asistido por Computador/estadística & datos numéricos , Inmunohistoquímica/métodos , Neoplasias Pulmonares/patología , Linfocitos Infiltrantes de Tumor/patología , Estructuras Linfoides Terciarias/patología , Automatización de Laboratorios , Recuento de Células , Colorantes , Eosina Amarillenta-(YS) , Hematoxilina , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Linfocitos Infiltrantes de Tumor/inmunología , Sensibilidad y Especificidad , Estructuras Linfoides Terciarias/diagnóstico por imagen , Microambiente Tumoral/genética , Microambiente Tumoral/inmunologíaRESUMEN
BACKGROUND: Somatic v-Raf murine sarcoma viral oncogene homolog B (BRAF) mutation, present in approximately 10% of metastatic colorectal cancer (mCRC) cases, is associated with poor prognosis. Patient outcome outside of clinical trials has only been reported in small series. We report real-world data on treatment and survival for BRAF-mutated (MT) patients at a single tertiary center, compared with a matched BRAF wild type (WT) control group. PATIENTS AND METHODS: All colorectal cancer patients tested for BRAF mutation, from October 2010 to November 2014 were identified. BRAF-MT mCRC cases were compared with an age and sex-matched BRAF-WT control group. Clinicopathological data were collected and survival calculated using the Kaplan-Meier method and comparisons made using Cox regression. RESULTS: Forty-three of 503 patients (8.5%) tested had BRAF-MT mCRC and were compared with 88 BRAF-WT controls. Median overall survival (mOS) was 18.2 months for BRAF-MT and 41.1 months for BRAF-WT mCRC patients (hazard ratio, 2.74; 95% confidence interval, 1.60-4.70; P < .001). Progression-free survival for BRAF-MT and WT patients, respectively, was: 8.1 months versus 9.2 months (P = .571) first-line, 5.5 months versus 8.3 months (P = .074) second-line, and 1.8 months versus 5.6 months (P = .074) third-line. Treatment using sequential fluoropyrimidine-based doublet chemotherapy was similar between both groups. Anti-epidermal growth factor receptor (EGFR) therapy was mainly given third-line with progressive disease in 90% (n = 9 of 10) of BRAF-MT patients at first restaging. CONCLUSION: In this case-control study, the poor mOS of BRAF-MT mCRC was associated with reduced treatment benefit beyond first-line. Sequential doublet chemotherapy remains a reasonable option in appropriately selected patients. BRAF-MT patients did not benefit from anti-EGFR therapy in this study. Recruitment to clinical trials is recommended to improve outcomes in BRAF-MT mCRC.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Proteínas Proto-Oncogénicas B-raf/genética , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Neoplasias Colorrectales/mortalidad , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Mutación , Supervivencia sin Progresión , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
PURPOSE: Leptomeningeal disease (LMD) is an uncommon complication of advanced breast cancer. The prognosis is poor, and although radiotherapy (RT), systemic and intra-thecal (IT) chemotherapy are accepted treatment modalities, efficacy data are limited. This study was designed to evaluate potential predictors of survival in this patient group. METHODS: Breast cancer patients with LMD diagnosed by MRI in a 10-year period (2004-2014) were identified from electronic patient records. PFS and OS estimates were calculated using Kaplan-Meier method, with planned sub-group analysis by treatment modality. Cox regression was employed to identify significant prognostic variables. RESULTS: We identified 182 eligible patients; all female, median age at LMD diagnosis 52.5 years (range 23-80). Ninety patients (49.5%) were ER positive/HER2 negative; 48 (26.4%) were HER2 positive, and 27 (14.8%) were triple negative. HER2 status was unknown in 17 (9.3%). Initial management of LMD was most commonly whole or partial brain RT in 62 (34.1%), systemic therapy in 45 (24.7%) or supportive care alone in 37 (20.3%). Fourteen patients (7.7%) underwent IT chemotherapy, of whom two also received IT trastuzumab. From diagnosis of LMD, the median PFS was 3.9 months (95%CI 3.2-5.0) and median OS was 5.4 months (95%CI 4.2-6.6). Patients treated with systemic therapy had the longest OS (median 8.8 months, 95%CI 5.5-11.1), compared to RT; 6.1 months (95%CI 4.2-7.9 months), IT therapy; 2.9 months (95%CI 1.2-5.8) and supportive care; 1.7 months (95%CI 0.9-3.0). On multivariable analysis, triple negative histology, concomitant brain metastases, and LMD involving both the brain and spinal cord were associated with poor OS. CONCLUSIONS: Breast cancer patients with triple negative LMD, concomitant brain metastases or LMD affecting both the spine and brain have the poorest prognosis. Clinical trials to identify more effective treatments for these patients are urgently needed.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Encefálicas/secundario , Neoplasias de la Mama/patología , Carcinomatosis Meníngea/tratamiento farmacológico , Carcinomatosis Meníngea/radioterapia , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Antineoplásicos Inmunológicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Encéfalo , Neoplasias Encefálicas/metabolismo , Neoplasias de la Mama/metabolismo , Supervivencia sin Enfermedad , Femenino , Humanos , Infusiones Intravenosas , Infusión Espinal , Estimación de Kaplan-Meier , Carcinomatosis Meníngea/secundario , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Receptor ErbB-2/metabolismo , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Estudios Retrospectivos , Médula Espinal , Tasa de Supervivencia , Trastuzumab/uso terapéutico , Adulto JovenRESUMEN
Cholangiocarcinoma (CCA) is a rare cancer arising from the biliary tree with a poor prognosis and limited therapeutic options. Recent large scale molecular characterisation studies have identified recurrent genetic alterations in CCA which may be amenable to therapeutic targeting. In this review we explore the genomic landscape of CCA and examine results from trials of molecularly targeted agents and immunotherapy in this disease. Challenges in CCA diagnosis, treatment and trial design are discussed and we reflect on future directions which may lead to improved outcomes for CCA patients.
RESUMEN
BACKGROUND: Prophylactic use of anticoagulants for septic patients in intensive care unit is a standard therapy for the prevention of venous thrombosis. Moreover, recent studies have demonstrated the anti-inflammatory effects of anticoagulants such as Factor Xa inhibitors and heparins. However, there have been no studies to examine the effects of fondaparinux and enoxaparin when applied in a sepsis model. Therefore, we examined the anti-inflammatory effects and bleeding events when these agents are applied in a lipopolysaccharide challenge model. METHODS: Wistar rats received lipopolysaccharides followed by a bolus infusion of fondaparinux, enoxaparin, or placebo. Microscopic observation of the mesenteric microcirculation for endothelial damage and measurement of bleeding area after vascular puncture was performed (n = 6 in each group). In another series, blood samples were taken, and blood cell counts, coagulation markers, and organ damage markers were measured (n = 6 in each). RESULTS: Both leukocyte adherence to vascular endothelium and endothelial damage were reduced in fondaparinux and enoxaparin groups. The bleeding area was markedly increased in the fondaparinux group. Coagulation markers were maintained better in the enoxaparin group. Levels of organ damage markers were significantly suppressed in both fondaparinux and enoxaparin groups (p < 0.01, compared with control, each). CONCLUSIONS: Fondaparinux and enoxaparin reduce organ dysfunction by decreasing endothelial damage. However, bleeding was more prominent in the fondaparinux group compared with the enoxaparin group at an equipotent dose for anti-Xa activity. Because the setting of this experiment is different from the clinical use, further study is required for the comparison of both pharmaceuticals.
Asunto(s)
Anticoagulantes/uso terapéutico , Endotelio Vascular/efectos de los fármacos , Endotoxemia/tratamiento farmacológico , Enoxaparina/uso terapéutico , Polisacáridos/uso terapéutico , Animales , Anticoagulantes/farmacología , Enoxaparina/farmacología , Inhibidores del Factor Xa , Fondaparinux , Hemorragia/prevención & control , Leucocitos/efectos de los fármacos , Lipopolisacáridos/farmacología , Masculino , Polisacáridos/farmacología , Ratas , Ratas WistarRESUMEN
Plastic compression enables rapid production of collagenous tissue like constructs without the need for cell based remodeling. We have previously reported testing spiral acellular and cell seeded constructs in-vivo. The constructs were implanted across the intercostal space of a lapine model designed to provide cyclical tensile loading in-vivo for up to 5 weeks. Results showed that cell seeded constructs elicit increased cellular infiltration, angiogenic response, mechanical integrity and decreased inflammatory response compared to acellular constructs. In this study the constructs were further tested for host muscle and nerve infiltration. Constructs were harvested, and stained for the myoblast marker desmin and neuronal marker neurofilament using an immunoperoxidase technique. We have found that host muscle cells start to migrate into the constructs by 3 weeks but did not reached the core of the spiral by 5 weeks, a delayed response. Significantly there is no innervation seen at 5 weeks in vivo in this model.