The striking geographical pattern of gastric cancer mortality in Spain: environmental hypotheses revisited

<p>Abstract</p> <p>Background</p> <p>Gastric cancer is decreasing in most countries. While socioeconomic development is the main factor to which this decline has been attributed, enormous differences among countries and within regions are still observed, with the main contributing factors remaining elusive. This study describes the geographic distribution of gastric cancer mortality at a municipal level in Spain, from 1994-2003.</p> <p>Methods</p> <p>Smoothed relative risks of stomach cancer mortality were obtained, using the Besag-York-Molliè autoregressive spatial model. Maps depicting relative risk (RR) estimates and posterior probabilities of RR being greater than 1 were plotted.</p> <p>Results</p> <p>From 1994-2003, 62184 gastric cancer deaths were registered in Spain (7 percent of all deaths due to malignant tumors). The geographic pattern was similar for both sexes. RRs displayed a south-north and coast-inland gradient, with lower risks being observed in Andalusia, the Mediterranean coastline, the Balearic and Canary Islands and the Cantabrian seaboard. The highest risk was concentrated along the west coast of Galicia, broad areas of the Castile & Leon Autonomous community, the province of Cáceres in Extremadura, Lleida and other areas of Catalonia.</p> <p>Conclusion</p> <p>In Spain, risk of gastric cancer mortality displays a striking geographic distribution. With some differences, this persistent and unique pattern is similar across the sexes, suggesting the implication of environmental exposures from sources, such as diet or ground water, which could affect both sexes and delimited geographic areas. Also, the higher sex-ratios found in some areas with high risk of smoking-related cancer mortality in males support the role of tobacco in gastric cancer etiology.</p

Deep-sequencing reveals broad subtype-specific HCV resistance mutations associated with treatment failure

A percentage of hepatitis C virus (HCV)-infected patients fail direct acting antiviral (DAA)-based treatment regimens, often because of drug resistance-associated substitutions (RAS). The aim of this study was to characterize the resistance profile of a large cohort of patients failing DAA-based treatments, and investigate the relationship between HCV subtype and failure, as an aid to optimizing management of these patients. A new, standardized HCV-RAS testing protocol based on deep sequencing was designed and applied to 220 previously subtyped samples from patients failing DAA treatment, collected in 39 Spanish hospitals. The majority had received DAA-based interferon (IFN) a-free regimens; 79% had failed sofosbuvir-containing therapy. Genomic regions encoding the nonstructural protein (NS) 3, NS5A, and NS5B (DAA target regions) were analyzed using subtype-specific primers. Viral subtype distribution was as follows: genotype (G) 1, 62.7%; G3a, 21.4%; G4d, 12.3%; G2, 1.8%; and mixed infections 1.8%. Overall, 88.6% of patients carried at least 1 RAS, and 19% carried RAS at frequencies below 20% in the mutant spectrum. There were no differences in RAS selection between treatments with and without ribavirin. Regardless of the treatment received, each HCV subtype showed specific types of RAS. Of note, no RAS were detected in the target proteins of 18.6% of patients failing treatment, and 30.4% of patients had RAS in proteins that were not targets of the inhibitors they received. HCV patients failing DAA therapy showed a high diversity of RAS. Ribavirin use did not influence the type or number of RAS at failure. The subtype-specific pattern of RAS emergence underscores the importance of accurate HCV subtyping. The frequency of “extra-target” RAS suggests the need for RAS screening in all three DAA target regions

Risk factors associated with Helicobacter pylori infection: A population-based study conducted in the province of Ourense Factores de riesgo asociados a la infección por Helicobacter pylori: Un estudio de base poblacional en la provincia de Ourense

Objectives: to identify the relationship between Helicobacter pylori infection and various factors that have been described in other studies in the general adult population in the province of Ourense. Material and methods: three hundred and eighty-three participants were enrolled in a study on the prevalence of Helicobacter pylori infection. All participants filled in a questionnaire under supervision, and the data obtained were examined by means of a univariate analysis. The odds ratio corresponding to each variable studied was calculated with their corresponding 95% confidence intervals. Furthermore, a multivariate analysis was performed. Results: the univariate analysis revealed an association between infection and: age, place of residence during childhood, current social status based on the head of the family's profession, current blue collar/white collar profession of the head of the family, sharing a bedroom during childhood, type of drinking water, and contact with animals during childhood. No association was found with respect to the presence of dyspeptic symptoms. The multivariate analysis disclosed that only age is an independent risk factor associated with infection. Conclusion: age has been identified as the only independent risk factor associated with Helicobacter pylori infection in this population-based study. The univariate analysis has detected other factors. No association has been identified with respect to dyspeptic symptoms.Objetivos: identificar en la población general adulta de la provincia de Ourense, la relación entre la infección por Helicobacter pylori y diversos factores que se han descrito en otros estudios. Material y métodos: se han incluido los 383 participantes en un estudio de prevalencia de la infección por Helicobacter pylori. Todos han completado un cuestionario bajo supervisión y los datos se han examinado mediante análisis univariante. Se han calculado las odds ratio correspondientes a cada variable estudiada, con sus intervalos de confianza al 95%. Además, se ha efectuado un análisis multivariante. Resultados: el análisis univariante demuestra asociación de la infección con: edad, lugar de residencia en la infancia, clase social actual por la profesión del cabeza de familia, profesión no manual/manual del cabeza de familia actual, compartir dormitorio en la infancia, tipo de agua de consumo y el contacto con animales en la infancia. No se ha encontrado asociación con la presencia de síntomas dispépticos. El análisis multivariante ha mostrado que solamente la edad es un factor de riesgo independiente asociado a la infección. Conclusión: en este estudio de base poblacional la edad es el único factor de riesgo independiente que se ha identificado asociado a la infección por Helicobacter pylori. En el análisis univariante se han identificado otros factores. No se demuestra asociación con síntomas dispépticos