Tumores Neuroendocrinos: un desafío transversal / Update on neuroendocrine tumors

Neuroendocrine Tumors (NETs) encompass a wide variety of tumors arising from neuroendocrine cells, which produce bioactive substances. The incidence of NETs increased significantly lately, becoming one of the most common tumors of the digestive tract. Their clinical presentation is as diverse as their capacity for hormone production. Carcinoid syndrome is the most common hormonal syndrome produced by NETs and is characterized by diarrhea, flushing and cardiac valvular lesions. New research brought multiple changes in the classification of these neoplasms and a new understanding about their diagnosis and treatment, promoting a multidisciplinary approach. Somatostatin analogues, radiation, biological, and cytotoxic drugs have improved the prognosis of these patients, which entails a great challenge for healthcare providers.

Diagnóstico prenatal y manejo perinatal en enfermedades raras / Prenatal diagnosis and management of rare diseases

El diagnóstico y manejo prenatal de enfermedades raras involucra un estudio multidisciplinario. Desde una visión obstétrica, herramientas de imagenología como la ultrasonografía y en menor medida la resonancia magnética fetal (RMF) son esenciales para el diagnóstico de anomalías morfológicas y sospecha de defectos cromosómicos. Para el diagnóstico de enfermedades cromosómicas el estudio de cariograma obtenido de vellosidades coriales, líquido amniótico o sangre fetal mediante técnicas invasivas tal como biopsia corial, amniocentesis o cordocentesis ha sido hasta hace poco el gold standard del diagnóstico. Nuevas técnicas moleculares capaces de detectar microdeleciones como es el microarray nos ha permitido aproximarnos al origen de las enfermedades raras. Se revisarán además algunos de los defectos anatómicos raros y su enfoque neonatal.

Prenatal diagnosis and management of rare diseases is a multidisciplinary task. From the obstetric vision, prenatal diagnosis is based on fetal images obtained by ultrasound or magnetic resonance and fetal chromosomes study. The study of fetal morphology allows us the diagnosis of fetal abnormalities and the suspicion of chromosomal defects. Fetal chromosomal study is obtained either by chorionic villus sampling, amniocentesis and cordocentesis, all associated to fetal risk. New screening techniques such as fetal DNA on maternal blood or the study of fetal micro deletions using micro Array on amniotic fluid has extended diagnostic opportunity of rare fetal diseases. We will review some of the most common rare diseases and the neonatal approach.

In vivo and in vitro estrogenic and progestagenic actions of Tibolone

Estrogen and progestin combination in hormone replacement therapy (HRT) increases the incidence of breast cancer, but decreases the endometrial cancer risk of unopposed estrogen. Therefore, a SERM such as Tibolone, that delivers the beneficial, but not the adverse side effects, of steroid hormones would be clinically advantageous. However, data from the Million Women Study suggests that Tibolone increases the risk of both breast and endometrial cancer. Herein, we assessed the estrogenic and progestagenic actions of Tibolone using transvaginal sonography studies and an in vitro model of breast (ZR-75, MCF7) and endometrial cancer (Ishikawa). The known cancer associated proteins (ER, EGFR, STAT5, tissue factor and Bcl-xL) were selected for study. Transvaginal sonography demonstrated that postmenopausal women treated with Tibolone displayed a thinner endometrium than in the late proliferative phase, but had a phenotype characteristic of the secretory phase, thus demonstrating the estrogenic and progestagenic actions of this SERM. In vitro, Tibolone acted as an estrogen in downregulating ER and upregulating Bcl-xL, yet as progesterone, increasing STAT5 and tissue factor in breast cancer cells. The increase in tissue factor by Tibolone correlated with its coagulative potential. Interestingly, EGFR was up-regulated by progesterone in the breast and by estrogen in endometrial cells, while Tibolone increased protein levels in both cell types. In conclusion, this study further demonstrates the estrogenic and progestagenic nature of Tibolone. The pattern of regulation of known oncogenes in cells of breast and endometrial origin dictates caution and vigilance in the prescription of Tibolone and subsequent patient monitoring.