Differences in Prevalence of Histologic Gastric Cancer Subtypes Between Mestizo and Mayan Populations in Guatemala.

PURPOSE: Although the intestinal subtype of gastric cancer (GC) is most prevalent around the world, a relatively high prevalence of the diffuse subtype has been reported in some populations of Central American countries, including Guatemala. This study aimed to investigate whether differences exist in the prevalence of the two GC subtypes in the two main ethnic groups in Guatemala, namely Mayan and Mestizo (known as Ladino in Guatemala), between whom significant socioeconomic disparities exist, and to determine whether there is an association with Helicobacter pylori/CagA seropositivity. MATERIALS AND METHODS: Participants included 65 patients with GC and 135 age-/sex-matched controls. Data on ethnicity, H. pylori and CagA seropositivity status, as well as tumor subtype (diffuse or intestinal) were collected. Logistic regression models were fitted to examine the relationship between predictor variables (age, sex, ethnicity, H. pylori, and CagA) and the binary response variable (tumor type). Model selection was based on the Akaike information criterion. RESULTS: The prevalence of diffuse GC was found to be significantly higher in the Mayan compared with the Mestizo population in Guatemala. Although seropositivity for CagA was significantly higher in patients with GC, there were no significant differences between the two GC subtypes. CONCLUSION: This study suggests that there are differences in the prevalence of intestinal and diffuse GC histologic subtypes between the two main ethnic groups in Guatemala. Further studies are warranted, given the potential higher prevalence of the more severe GC subtype in the most vulnerable population.

Perfil de citocinas Th1, Th2, Th17 y otras citocinas pro inflamatorias (IL-1ß, IL-6 y TNFα) en el plasma de pacientes con cáncer gástrico / Th1, Th2, Th17 cytokine profile and other pro-inflammatory cytokines (IL-1ß, IL-6 and TNFα) in the plasma of patients with gastric cancer

El cáncer gástrico (CG) es la neoplasia del tubo digestivo más prevalente en el mundo, asociada a factores genéticos del hospedero y externos, como infección por Helicobacter pylori. La patogénesis incluye inflamación crónica mediada por citocinas del microambiente tumoral, detectables sistémicamente. Estudios previos reportan niveles séricos de citocinas y su contribución al diagnóstico de CG. El presente estudio analiza el perfil de citocinas del tipo de Th1(IFNγ), Th2(IL-4 e IL-10), Th17(Th-17A) y otras pro inflamatorias: IL-1ß, IL-6 y TNF-α, en plasma de 70 casos de pacientes con CG comparándolos con 132 sujetos sanos equiparables en edad y sexo. Los casos provinieron del Hospital Roosevelt e Instituto Nacional de Cancerología de Guatemala (Incan) y formaron parte de un estudio previo. Se analizó la base de datos clínicos, patológicos y epidemiológicos. Se midieron los niveles de citocinas utilizando el sistema "MSD MULTI-SPOT Assay System". La edad promedio de los casos fue 59.5 años, (DE 13.0), 51%, eran positivos para IgG anti H. pylori. Un 71% presentó adenocarcinoma grado III (Borrman), según clasificación de Lauren 55% tenían tipo intestinal. Las siete citocinas cuantificadas se encontraron significativamente elevadas (p < .05) en el plasma de los casos respecto a sus controles. Los casos de CG tipo difuso presentaron niveles de IFNγ significativa-mente elevados. Por regresión logística, las citocinas IL-6 e IL-10, están asociadas significativamente a CG (p < .05) independientemente del estatus de infección por H. pylori. Se destacan la IL-6 e IL-10 como las principales citocinas asociadas a la presencia de CG.

Gastric cancer (GC) is the most prevalent gastrointestinal neoplasm in the world, associated with host and external genetic factors, such as Helicobacter pylori infection. The pathogenesis includes chronic inflammation mediated by cytokines of the tumor microenvironment, systemically detectable. Previous studies report serum levels of cyto-kines and their contribution to the diagnosis of GC. The present study analyzes the profile of cytokines of the type Th1 (IFNγ), Th2 (IL-4 and IL-10), Th17 (Th-17A) and other pro-inflammatory: IL-1ß, IL-6 and TNF-α, in plasma of 70 cases of patients with GC compared with 132 healthy subjects comparable in age and sex. The cases came from the Roosevelt Hospital and the National Cancer Institute of Guatemala -Incan- and were part of a previous study. The clinical, pathological and epidemiological databases were analyzed. Cytokine levels were measured using the "MSD MULTI-SPOT Assay System". The average age of the cases was 59.5 years, (SD 13.0), 51% were positive for IgG anti H. pylori, 71% had grade III adenocarcinoma (Borrman), according to Laurenís classification, 55% had intestinal type. The seven cytokines quantified were found to be significantly elevated (p < .05) in the plasma of the cases compared to their controls. The diffuse GC cases presented significantly elevated IFNγ levels. By logistic regression, the cytokines IL-6 and IL-10 are significantly associated with GC (p < .05) regardless of the H. pylori infection status. IL-6 and IL-10 stand out as the main cytokines associated with the presence of GC.

Biomarcadores suPAR y citocinas en la detección temprana de cáncer gástrico / suPAR and cytokines as biomarkers in early detection of gastric cancer

El cáncer gástrico (CG) es un problema prevalente a nivel mundial, presentándose aproximadamente 18 millones de casos nuevos en el año 2018, representa el 5.7% del total de cánceres, siendo la quinta neoplasia maligna más común en el mundo. En Guatemala se sitúa entre los primeros cinco cánceres respecto a morbilidad y mor-talidad. El CG se ha asociado de manera contundente a infección por Helicobacter pylori el cual desencadena un proceso inflamatorio crónico; adicionalmente algunas cepas de H. pylori producen toxinas bacterianas capaces de inducir cambios celulares que conllevan al desarrollo del proceso neoplásico. La alta mortalidad por CG en parte, se relaciona con la etapa tardía en la que se diagnostica ya que se requiere el uso de métodos invasivos, lo que dificulta su detección temprana. El objetivo de la presente revisión, fue realizar una narrativa de los estudios y las evidencias científicas, respecto de la identificación de biomarcadores séricos en la detección temprana del cáncer gástrico. Se revisaron dos tipos de biomarcadores, la proteína soluble uPAR (suPAR) que es el receptor del activador del plasminógeno (uroquinasa) y promotora de angiogénesis y por otro lado, la detección sérica de las citocinas IL-1ß, IL-6, TNFα, IL-10, IFNγ, IL-4 e IL-17 en el CG así como su potencial utilidad en su detección temprana. Estos biomarcadores fueron seleccionados por la ventaja que tendrían de ser métodos no invasivos que podrían mejorar la detección, tratamiento y pronóstico de esta enfermedad.

Gastric cancer (GC) is a prevalent problem worldwide, presenting approximately 18 million new cases in 2018, representing 5.7% of all cancers, being the fifth most common malignancy in the world. In Guatemala it is among the first five cancers in terms of morbidity and mortality. CG has been strongly associated with Helicobacter pylori infection, which triggers a chronic inflammatory process; additionally, some strains of H. pylori produce bacterial toxins capable of inducing cellular changes that lead to the development of cancer. The high mortality due to GC in part is related to the late stage in which it is diagnosed since the use of invasive methods is required, making it difficult to detect it early. The objective of this review was to make a narrative of the studies carried out and the scientific evidence regarding the identification of serum biomarkers in the early detection of gastric cancer. Two types of biomarkers were reviewed, the soluble protein uPAR (suPAR) which is the receptor for plasminogen activator (urokinase) and promoter of angiogenesis and, on the other hand, serum detection of cytokines IL-1ß, IL-6, TNFα, IL-10, IFNγ, IL-4 and IL-17 in the CG as well as its potential usefulness in its early detection. These biomarkers were selected for the advantage they would have of being non-invasive methods that could improve the detection, treatment and prognosis of this disease.