The Mexican consensus on the detection and treatment of early gastric cancer. / Consenso mexicano sobre detección y tratamiento del cáncer gástrico incipiente.

Gastric cancer is one of the most frequent neoplasias in the digestive tract and is the result of premalignant lesion progression in the majority of cases. Opportune detection of those lesions is relevant, given that timely treatment offers the possibility of cure. There is no consensus in Mexico on the early detection of gastric cancer, and therefore, the Asociación Mexicana de Gastroenterología brought together a group of experts and produced the "Mexican consensus on the detection and treatment of early gastric cancer" to establish useful recommendations for the medical community. The Delphi methodology was employed, and 38 recommendations related to early gastric cancer were formulated. The consensus defines early gastric cancer as that which at diagnosis is limited to the mucosa and submucosa, irrespective of lymph node metástasis. In Mexico, as in other parts of the world, factors associated with early gastric cancer include Helicobacter pylori infection, a family history of the disease, smoking, and diet. Chromoendoscopy, magnification endoscopy, and equipment-based image-enhanced endoscopy are recommended for making the diagnosis, and accurate histopathologic diagnosis is invaluable for making therapeutic decisions. The endoscopic treatment of early gastric cancer, whether dissection or resection of the mucosa, should be preferred to surgical management, when similar oncologic cure results can be obtained. Endoscopic surveillance should be individualized.

[Helicobacter pylori. Its relationships and morphological controversies]. / Helicobacter pylori. Sus relaciones y controversias morfológicas.

After Helicobacter pylori was described in 1984, it has been related to numerous benign and malignant morphological disturbances. The distribution of the gastroduodenal disease, their histological expressions and their controversial topics regarding their relationship with HP are better known today. The aim of this paper is review some of these features.

Histological types of gastric cancer in Mexico.

BACKGROUND: Gastric cancer is the second leading cause of malignant tumours in Mexico. The distribution of the histological types of this tumour has not been estimated from a population-based representative sample. METHODS: The histological types of gastric cancer according to the Lauren classification and selected socio-demographic characteristics for 220 patients from different socioeconomic levels are reported. The study population represents 66% of all new gastric cancer cases during 1989-1990 reported to the Mexico City Cancer Registry. The patients attended four public hospitals, seven social security hospitals and four private hospitals in Mexico City. A second histological diagnosis was performed by one pathologist. RESULTS: No specific histological type of gastric cancer predominated since the estimated distribution for intestinal gastric cancer was 44.5%, for diffuse gastric cancer 43.2% (and the remaining 12.3% corresponded to indeterminate tumours). The distribution of intestinal and diffuse gastric cancer did not vary significantly according to socioeconomic level or medical care unit and it showed a clear relationship with gender, the intestinal type of gastric cancer being more common among males. CONCLUSIONS: Mexico may not have been affected by the gastric cancer epidemic at the beginning of the twentieth century but the available information and the results of this study are only useful to demonstrate that, currently, no histological type of gastric cancer (according to Lauren's classification) predominates significantly in this country.

[Practical aspects regarding sample size in clinical research]. / Aspectos prácticos sobre el tamanño de la muestra en 1a investigación clínica.

BACKGROUND: The knowledge of the right sample size let us to be sure if the published results in medical papers had a suitable design and a proper conclusion according to the statistics analysis. To estimate the sample size we must consider the type I error, type II error, variance, the size of the effect, significance and power of the test. To decide what kind of mathematics formula will be used, we must define what kind of study we have, it means if its a prevalence study, a means values one or a comparative one. In this paper we explain some basic topics of statistics and we describe four simple samples of estimation of sample size.

[Granulomatous hepatitis secondary to ingestion of carbamazepine. Report of a case]. / Hepatitis granulomatosa secundaria a la ingestión de carbamazepina. Informe de un caso.

A 51-year-old man with epilepsy received carbamazepine during three weeks. He developed fever, jaundice, dark urine and pale stools. Laboratory data showed hepatocellular injury and cholestasis; six weeks after withdrawal of the drug these abnormalities returned to normal limits. The liver biopsy showed acute cholangitis, bile duct injury, granulomas and eosinophils in the portal areas.