ABSTRACT
Abstract Background: Hepatocarcinogenesis has a variety of risk factors. In Mexico City, autopsies found 14% of hepatocellular carcinomas (HCCs) without cirrhosis. Objective: The objective of the study was to explore if HCCs carry the TP53 R249S mutation that has linked them to aflatoxin exposure and describe the associated risk factors. Methods: A retrospective review of consecutive cases of HCC was performed. Exposure to hepatotropic viruses, alcoholism, metabolic diseases, diabetes mellitus, and hypertension, as well as episodes of ascites, portal hypertension, and body mass index were retrieved. Slides were re-reviewed, macrodissected and DNA was extracted. TP53 exon 7 was amplified, purified, and used as a template for sequencing. Results: In 14 years, 74 HCCs were identified in 1863 (4%) consecutive liver biopsies. No data were available in five excluded patients; the rest was submitted to exon 7 screening. Patients had a median age of 62 years, and 46 (67%) were male. Stage 4 fibrosis was observed in 46 patients (67%) and their associated risk factors were hepatitis C virus (39%, 18/46), alcoholism (20%, 9/46), hepatitis B virus (2%, 1/46), and 18 were cryptogenic. Fibrosis stage 3 or lower was observed in 23 (33%) patients without demonstrated liver disease; 8/23 had diabetes and 6/23, systemic hypertension. Steatohepatitic variants of HCC were observed in 4 and in 5, the remnant liver had steatohepatitis. A 238-bp fragment was obtained in each tumor without the expected TP53 R249S mutation. Conclusions: There was no evidence of aflatoxin exposure in HCCs, with and without the known classical risk factors. One-third of non-cirrhotic HCCs had steatohepatitis or conditions associated to metabolic syndrome. (REV INVEST CLIN. 2020;72(5):316-22)
ABSTRACT
Se presentan modelos estructurales de variables asociadas con la adquisición de la lengua escrita y con el desempeño en dominios de la lectura y la escritura. El propósito de nuestro trabajo es fundamentar con ejemplos derivados de situaciones y temas reales, la utilidad potencial de los modelos estructurales en la investigación en lengua escrita, tanto en lo que al diseño de la recolección de información corresponde, como para el análisis y la interpretación de los datos. También nos interesó mostrar cómo el análisis de Ias relaciones funcionales entre distintas variables permite al investigador ir más allá de los supuestos acerca de las relaciones causales en el inicio de la alfabetización formal