RESUMEN
Microsatellite instability (MSI) is a hallmark tool for Lynch syndrome (LS) screening and a prognostic marker for sporadic colorectal cancer (CRC). In regions with limited resources and scarce CRC molecular characterization as South America, the implementation of universal MSI screening is under debate for both its purposes. We sought to estimate the frequency of BAT26 in colorectal adenocarcinomas and to determine associated clinical and histological features. Consecutive patients from a CRC registry were included. BAT26 determination was performed in all cases; if instability was found, immunohistochemistry (IHC) and BRAF mutation analyses were done, as appropriate. Differences were assessed by chi-squared or Fisher's exact test, or by T test or Mann-Whitney. Multiple logistic regression was used to identify factors independently associated with BAT26-unstable tumors. We included 155 patients; mean age was 65.6 (SD 14.4) and 56.1% were male. The frequency of BAT26-unstable tumors was 22% (95% CI 15.7-29.3). Factors independently associated with BAT26-unstable tumors were right colon localization (OR 3.4, 95% CI 1.3-8.7), histological MSI features (OR 5.1, 95% CI 1.9-13.6) and Amsterdam criteria (OR 23.2, 95% CI 1.9-286.7). IHC was altered in 85.3% BAT26-unstable tumors and 70.6% lacked MLH1 expression; 47.8% of these harbored BRAF V600E mutation. We provide evidence to link the frequency of BAT26 to an increased diagnostic yield (up to 1.4-folds) of suspected LS cases in comparison to the revised Bethesda guidelines alone. In regions with limited resources, clinical and histological features associated with BAT26-unstable status could be useful to direct MSI screening in sporadic CRCs and may help guide clinical care and future research.
Asunto(s)
Adenocarcinoma/genética , Biomarcadores de Tumor/genética , Neoplasias Colorrectales/genética , Marcadores Genéticos/genética , Repeticiones de Microsatélite/genética , Adenocarcinoma/diagnóstico , Adenocarcinoma/patología , Adulto , Anciano , Argentina , Estudios de Cohortes , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/patología , Neoplasias Colorrectales Hereditarias sin Poliposis/diagnóstico , Neoplasias Colorrectales Hereditarias sin Poliposis/genética , Neoplasias Colorrectales Hereditarias sin Poliposis/patología , Análisis Mutacional de ADN , Femenino , Humanos , Masculino , Inestabilidad de Microsatélites , Persona de Mediana EdadRESUMEN
Hereditary hemorrhagic telangiectasia (HHT) usually presents in association with pulmonary arteriovenous malformations (PAVMs). In addition, the incidence of venous thromboembolism tends to be increased in these patients. A 74-year-old female with HHT presented with cyanosis and hypoxemia. Contrast-enhanced multislice computed tomography (MSCT) revealed two left PAVMs and one in the right upper lobe. Both left PAVMs were treated with embolotherapy. Follow-up MSCT revealed an incidental pulmonary embolism in the right pulmonary branches. Deep venous thrombosis was confirmed and anticoagulation was initiated. Follow-up MSCT revealed the resolution of thromboembolism. Finally, embolotherapy was performed. This case illustrates the chronic adaptation to hypoxemia and adds further evidence to the relative safety of anticoagulation treatment in these patients.