RESUMO
PURPOSE: Cancers can be hidden by high breast density (BDen)- the masking effect (ME). BDen is also a modifiable and highly prevalent breast cancer risk (BCR) factor. The purposes of this study were to determine how much glandular volume (GVol), breast volume (BVol) and their ratio: BDen change during the menstrual cycle, and if these changes could affect ME or be relevant to results of interventional studies aiming to diminish BCR using these parameters as surrogates. METHODS: We retrieved GVol, BVol and BDen data values obtained from 39,997 right mammograms performed with photon counting technique of 19,904 premenopausal women who reported their first day of last menses (FDLM). Many women had more than one study included over the years (with a different FDLM) but were not studied longitudinally. We segregated women by age (yearly), divided the menstrual cycle in 4 weeks, and assigned results with respect to the FDLM. RESULTS: All parameters vary cyclically, with higher values in week 4 (GVol and BDen) or week 1 (BVol). Mean inter-week differences were very small for the three parameters, and diminished with age. However, especially in the youngest women, inter-week differences could be more than 10% for BDen, 15% for GVol, and 50% for BVol. CONCLUSION: Small inter-week mean differences almost certainly rule out relevant changes to ME directly attributable to BDen. However, the possibility of large differences during the menstrual cycle in younger women, who are the ideal targets of interventional studies to diminish BCR, might distort results and should be accounted for.
Assuntos
Densidade da Mama , Neoplasias da Mama/patologia , Mama/patologia , Mamografia/métodos , Ciclo Menstrual , Pré-Menopausa , Adulto , Fatores Etários , Mama/diagnóstico por imagem , Neoplasias da Mama/diagnóstico por imagem , Feminino , Humanos , Fatores de Risco , Fatores de TempoRESUMO
Con el objetivo de conocer la situación nutricional de los alumnos de la unidad educativa "Santiago Mariño", fué realizada en el año 2005 una evaluación antropométrica de 236 escolares, a los cuales se les pesó, talló y tomó su edad en años cumplidos. El déficit de peso para la edad fue de 10,1%, de los cuales 5,9%, presentan peso deficiente o desnutrición global y 4,2% están a riesgo de desnutrición. El déficit de peso para la talla, fue de 18,3%, lo cual significa que los mismos presentan desnutrición aguda. El indicador talla para la edad registró un déficit de 5,1%, significando 1,7% de desnutrición crónica y 3,4% a riesgo de desnutrición. Las niñas tienen una probabilidad de 2,9 veces más de presentar exceso de talla para la edad que los varones (p>0.05). Según el Indice de Masa Corporal 13,6% de los alumnos sufren déficit nutricional y 3,4% obesidad.
As to assess the nutritional status of the pupils in "Santiago Mariño" school, an anthropometric evaluation was performed during 2005 on 236 students, determining height, weight and checking their exact age. 10.1% of the sample showed weight deficit according to age, among them, 5.9% had defficient weight or global undernowrishment and 4.2% were on risk. Weight deficit according to height was 18.3% which implies acute under nourishment. Indicator size / age showed a 5.1% deficit which means 1.7% of cronic undernourishment and 3.4% of risk. Female pupils have a 2.9% higher probability of reporting excess of height according to age in comparison with boys (1>0.05). According to Mass Corporal index nutritional deficit was assessed in 13.6% of the pupils and obesity in 3.4%.