Inês Marques

Sustained relief of obstructive symptoms for the remaining life of patients following placement of an expandable metal stent for malignant colorectal obstruction

BACKGROUND self-expanding metal stents are currently being used as a definitive palliative treatment for malignant colorectal obstruction in patients with incurable disease. Few studies have followed large numbers of patients from stent placement until death, and those few have reported conflicting results in the long-term clinical outcome data. AIMS this study evaluated the clinical effectiveness of stent placement for malignant colorectal obstruction throughout the patients lives and related factors affecting stent patency, clinical success and complications. METHODS this was a multicentre, retrospective study of 89 consecutive patients who had undergone attempted expandable stent placement for symptomatic malignant colorectal obstruction during a 10-year period. Data were collected to analyse the sustained relief of obstructive symptoms throughout the patients lives, as well as the technical success, immediate clinical success, stent patency, complications, reinterventions, survival, prognostic factors associated with stent patency and long-term clinical efficacy and risk factors for complications. RESULTS technical and immediate clinical success were achieved in 95.5% and 91.0% of patients, respectively. A total of 68 out of 89 patients (76.4%) maintained relief of obstruction from stent implantation until death without reintervention. Twenty patients (22.5%) had complications including perforation (n = 4; 4.5%), stent obstruction (n = 8; 9.0%), migration (n = 5; 5.6%) and haemorrhage (n = 3; 3.4%). Stent-related mortality was seen in 1 patient (1.1%). The estimated median survival and estimated mean stent patency were 87.0 and 322.7 days, respectively. In total, 12 of the initial 89 patients (13.5%) needed a colostomy for long-term relief of the obstructive symptoms. Univariate and multivariate analysis detected no significant prognostic factors associated with stent patency, long term clinical efficacy and risk factors for complications; however, the multivariate logistic model revealed a non-significant trend by which the use of chemotherapy was a risk factor for migration (OR = 11.89; p = 0.06). CONCLUSIONS for palliation of incurable malignant colorectal obstruction, expandable stents can provide sustained relief of obstruction in approximately 75% of patients. The procedure is associated with acceptable morbidity, need for reintervention and minimal mortality.

Identification of somatic TERT promoter mutations in familial nonmedullary thyroid carcinomas

The genes causing familial nonmedullary thyroid carcinoma (FNMTC) identified to date are only involved in a small fraction of the families. Recently, somatic mutations in TERT promoter region and in EIF1AX gene were reported in thyroid tumours of undefined familial status. The aim of this study was to investigate the role of TERT and EIF1AX mutations in familial thyroid tumours.

The role of EIF1AX in thyroid cancer tumourigenesis and progression

AbstractPurposeThe EIF1AX gene was recently described as a new thyroid cancer-related gene. Its mutations were mainly reported in poorly differentiated (PDTC) and anaplastic thyroid cancers (ATC), but also in well-differentiated thyroid cancer (WDTC) and in benign thyroid lesions, although less frequently. Our aim was to address whether EIF1AX mutations are present in the different stages of thyroid tumourigenesis (from hyperplasia to well-differentiated and to poorly differentiated/undifferentiated lesions), and to clarify its role in this process.MethodsWe analysed the EIF1AX gene in a series of 16 PDTC and ATC cases with coexistent well-differentiated regions and/or benign lesions. In EIF1AX mutant cases we also assessed the presence of RAS genes mutations. ResultsWe identified the mutation p.Ala113_splice in the EIF1AX gene in two PDTCs (neither present in the well-differentiated counterparts nor in the benign areas). One of these tumours also evidenced the mutation p.Glu61Arg in NRAS in both poorly and well-differentiated regions, further suggesting that the EIF1AX p.Ala113_splice mutation could be associated with tumoural progression. In another patient we did not find any EIF1AX alteration in the PDTC component, but we detected the EIF1AX p.Gly6_splice mutation in the PTC area (both regions were RAS wild-type). This mutation did not seem to be related with dedifferentiation.ConclusionsAccording to our results, distinct mutations on EIF1AX may be related to different phenotypes/behaviours. Despite being a small series, which reflects the difficulty in retrieving PDTC and ATC surgical samples with well-differentiated and/or benign areas, our study may provide new insights into thyroid cancer tumourigenesis and dedifferentiation.

Combined Use of Object-Based Models, Multipoint Statistics and Direct Sequential Simulation for Generation of the Morphology, Porosity and Permeability of Turbidite Channel Systems

This work presents a new methodology for simulating the morphology and petrophysical properties of hydrocarbon reservoirs in turbidite channel systems. The simulation of the morphology uses an object-based algorithm that imposes multipoint statistics of azimuth angle classes and cdfs of width and thickness as measured from training images of channels. A facies is then assigned to each block of the reservoir grid according to a conceptual model of facies both laterally and vertically within the channels. Following this, as each facies has a specific cdf for both porosity and permeability, simulated images of these petrophysical properties are generated using direct sequential simulation (DSS) with local histograms. For illustrative purposes, a case study of a reservoir in the Lower Congo Basin is presented.