Influencia de la mamografía digital en la detección y manejo de microcalcificaciones / Impact of digital mammography in the detection and management of microcalcifications

Objetivo. Valorar si la introducción de la mamografía digital (MD) en el cribado del cáncer de mama ha supuesto cambios en cuanto a la detección y manejo de las microcalcificaciones. Material y métodos. Se ha realizado un estudio retrospectivo de los indicadores de rendimiento de un programa de cribado del cáncer de mama que se relacionan con el diagnóstico de microcalcificaciones (tasas de recitación y de recomendación de controles intermedios después del cribado, tasa de indicación de procedimientos invasivos por microcalcificaciones, y su valor predictivo positivo, tasa de detección por microcalcificaciones y número de carcinomas ductales in situ [CDIS] diagnosticados). Se han comparado los resultados obtenidos con la mamografía digital directa (septiembre 2008-agosto 2009) frente a la mamografía analógica (septiembre 2006-agosto 2007). Para el análisis estadístico se utilizaron la Prueba de X2 y medidas de asociación. Resultados. Con MD se ha observado un aumento significativo de las tasas de recitación (de 50,8 a 64‰), de realización de controles intermedios (de 9,41 a 18,7‰), de indicación de pruebas invasivas (de 1,88 a 3,01‰), de cánceres detectados por microcalcificaciones (de 0,86 a 1,36‰) y del número de CDIS. Conclusión. La MD directa ha mejorado la detección de microcalcificaciones incrementando el número de CDIS diagnosticados, sin disminuir el valor predictivo positivo de los procedimientos invasivos indicados por microcalcificaciones. Sin embargo, ha tenido un efecto negativo por el aumento en la tasa de recitación y de indicación de seguimiento a corto plazo, posiblemente debido a la dificultad de comparación con estudios analógicos anteriores(AU)

Objective. To determine whether the introduction of digital mammography in breast cancer screening has resulted in changes in the detection and management of microcalcifications. Material and methods. We retrospectively studied the performance indicators of our breast cancer screening program that are related to the diagnosis of microcalcifications (rates of recall and recommendation of intermediate follow-up after screening, rate of indication of invasive procedures for microcalcifications and their positive predictive value, detection rate for microcalcifications, and number of ductal carcinomas in situ (DCIS) diagnosed). We compared the results obtained using direct digital mammography (september 2008-august 2009) with those obtained using analog mammography (september 2006-august 2007). Statistical analysis. Chi-square test and measures of association. Results. We found that using digital mammography led to significant increases in the recall rate (from 50.8 to 64‰), in the rate of intermediate follow-up after screening (from 9.41 to 18.7‰), in the rate of indication for invasive procedures (from 1.88 to 3.01‰), in the cancers detected through microcalcifications (from 0.86 to 1.36‰), and in the number of DCIS diagnosed. Conclusion. Direct digital mammography has improved the detection of microcalcifications, increasing the number of DCIS diagnosed without decreasing the positive predictive value of the invasive procedures indicated for microcalcifications. However, direct digital mammography has had a negative effect by increasing the recall rate and indication for short-term follow-up, possibly due to the difficulty of comparing the findings with those of earlier analog mammograms(AU)

[Impact of digital mammography in the detection and management of microcalcifications]. / Influencia de la mamografía digital en la detección y manejo de microcalcificaciones.

OBJECTIVE: To determine whether the introduction of digital mammography in breast cancer screening has resulted in changes in the detection and management of microcalcifications. MATERIAL AND METHODS: We retrospectively studied the performance indicators of our breast cancer screening program that are related to the diagnosis of microcalcifications (rates of recall and recommendation of intermediate follow-up after screening, rate of indication of invasive procedures for microcalcifications and their positive predictive value, detection rate for microcalcifications, and number of ductal carcinomas in situ (DCIS) diagnosed). We compared the results obtained using direct digital mammography (september 2008-august 2009) with those obtained using analog mammography (September 2006-August 2007). STATISTICAL ANALYSIS: Chi-square test and measures of association. RESULTS: We found that using digital mammography led to significant increases in the recall rate (from 50.8 to 64‰), in the rate of intermediate follow-up after screening (from 9.41 to 18.7‰), in the rate of indication for invasive procedures (from 1.88 to 3.01‰), in the cancers detected through microcalcifications (from 0.86 to 1.36‰), and in the number of DCIS diagnosed. CONCLUSION: Direct digital mammography has improved the detection of microcalcifications, increasing the number of DCIS diagnosed without decreasing the positive predictive value of the invasive procedures indicated for microcalcifications. However, direct digital mammography has had a negative effect by increasing the recall rate and indication for short-term follow-up, possibly due to the difficulty of comparing the findings with those of earlier analog mammograms.

Estadificación prequirúrgica del cáncer de recto mediante RM y correlación radiopatológica / Preoperative staging MRI for rectal cancer and pathologic correlation

Fundamento. El objetivo de este trabajo es revisar lautilidad de la RM pélvica para la estadificación del cáncerde recto y establecer una correlación radiopatológica.Material y métodos. Se realizó un análisis retrospectivode 120 pacientes con una edad comprendida entre 43 y87 años a los que se realizó una RM pélvica para el estadiajede cáncer rectal en nuestro hospital entre los años2005 y 2010. Se catalogaron los pacientes de acuerdo ala clasificación TNM.Resultados. De los 120 pacientes, 80 fueron tratadoscon RT y/o QT neoadyuvante debido a que presentabanenfermedad localmente avanzada (T3-T4), afectaciónganglionar (N1-N2) o metástasis resecables. Con los40 pacientes que no fueron sometidos a tratamientoneoadyuvante se realizó una correlación entre los hallazgosde la RM y de la anatomía patológica con unaprecisión diagnóstica para predecir el estadio T del72%, el estadio N del 60% y la distancia a la FMR del87,5%.Conclusión. La RM pélvica es una técnica útil para laestadificación locorregional del cáncer de recto, obteniendouna buena correlación radiopatológica aunquela identificación de la afectación ganglionar es todavíaun problema diagnóstico(AU)

Background. Our aim is to asses the accuracy of MRIfor preoperative rectal cancer staging and to establisha histopathologic correlation.Material and methods. A retrospective analysis wasperformed on 120 patients aged between 43 and 87 withhistologically proven rectal cancer who underwent MRIfor preoperative staging in our hospital between 2005and 2010. Patients were categorized according to theTNM classification.Results. Eighty of 120 patients underwent adjuvantchemoradiotheraphy because they had advanceddisease (T3-T4), lymph node involvement (N1-N2) orresectable metastases. With 40 patients who didn’tundergo neoadjuvant therapy we performed a correlationbetween MRI and histopathological findings witha diagnostic accuracy in predicting T stage of 72%, Nstage of 60% and distance to the mesorectal fascia of87,5%.Conclusion. Pelvic MRI is a useful technique for locoregionalstaging of rectal cancer with a good radiopathologiccorrelation although the identification of nodaldisease is still a diagnostic problem(AU)

A tutorial in genetic epidemiology and some considerations in statistical modeling

A new door has been opened to health professionals since the completion of the map of the human genome was announced in 2003, coinciding with the 50th anniversary of the discovery of the DNA helical structure by Watson and Crick in 1953. The continuous updating of the technology has enabled scientists to simultaneously analyze thousands of variables for genome analysis. These advances have created new opportunities to locate genes, to assess the gene-gene relationship, to measure the gene-environment interaction, to describe gene products, and to evaluate the gene-disease relationship. In epidemiology, new strategies have been developed to determine cause-effect relationship in case-control studies and cohort studies. With the information provided by the Human Genome Project, new epidemiological designs and new statistical methodology have been developed. The addition of molecular biology to traditional epidemiological approaches has given birth to a new discipline known as genetic epidemiology. The objective of this paper is to provide an introduction to concepts needed for assessing the association between genes and specific diseases in population based studies. Firstly, a description of the genetic concepts is presented as a framework for the epidemiological designs and the statistical procedures that have been utilized in genetic epidemiology. Then, a description of the different designs in genetic epidemiology is presented with the most recent publications. Finally, some considerations in the statistical analysis for genetic epidemiology are discussed.

Contribution of HLA class II genes to end stage renal disease in mexican patients with type 2 diabetes mellitus.

To analyze the contribution of MHC class II genes in type 2 diabetes mellitus (DM) with end stage renal disease (ESRD), we examined the distribution of HLA-DRB1, DQA1, DQB1 loci in Mexican Mestizos of Central Mexico, using PCR-SSOP and PCR-SSP. Three groups were included: 47 type 2 diabetic ESRD patients; 42 patients with ESRD and 50 type 2 DM patients with no kidney complication. The results were compared with those of 101 controls of the same area. The median since DM was first diagnosed, was 18 years prior to the onset of ESRD. The frequencies of DRB1*1502 and DQB1*0501 were increased in DM patients with ESRD (p = 0.004; RR = 7.4, CI = 1.5-37; EF = 0. 13; p = 0.007; RR = 2.9, CI = 2.3-3.5, EF = 0.21, respectively). In contrast, DRB1*0407 was decreased in the same group (p = 0.0008, RR = 0.2; CI = 0.035-0.70, PF = 0.19). Diabetic patients with DRB1*1502 are 8.8 times more likely to develop ESRD, independently of the duration time of DM. DRB1*1502 contributes to the susceptibility to ESRD while DRB1*0407 is involved in protection. The residue at DRB1-74 differs in these alleles: DRB1*0407 has glutamic acid and DRB1*1502 has an alanine, suggesting that this substitution may be important for both, peptide anchoring and for presentation to the T cells.

Molecular estimates of primate divergences and new hypotheses for primate dispersal and the origin of modern humans.

The concept of recent hominoid divergences has been a mainstay in molecular primatology since the 1970's. However, the ages allocated to the calibration points used to establish these divergence times and the estimates resulting from their application, notably the commonly accepted divergence between Pan (chimpanzees) and Homo 5 million years before present (MYBP), are now palaeontologically refutable. Here we estimate the ages of various primate divergences using three references with a more detailed fossil record than any of the traditional primate calibration points. Our findings suggest that the latter yield datings that are too recent by a factor of about two. For example, our estimates place the divergence between Pan and Homo 10.5-13 MYBP. The revised estimates of primate divergence times suggest a new hypothesis for primate evolution and dispersal: that the divergence between strepsirhines (lorises, lemurs) and anthropoids was contemporary with the break-up of Southern continents about 90 MYBP, with strepsirhines becoming isolated on Madagascar and later dispersing to Africa (and Asia) and anthropoids evolving in South America and subsequently colonizing Africa (and Asia), or possibly North America. In addition we present a new hypothesis, which accommodates the strikingly similar coalescence times for human mitochondrial DNA and the Y-chromosome. This hypothesis posits a common mitochondrial and Y-chromosome bottleneck about 400,000 years ago, associated with the origination of the human 2n = 46 karyotype, obstructing genetic exchange with the 2n = 48 Homo contemporaries.

Strong association of HLA class II sequences in Mexicans with Vogt-Koyanagi-Harada's disease.

Vogt-Koyanagi-Harada's syndrome (VKH) is an autoimmune disease prevalent in Mongoloids with evident participation of HLA. The aim of this study was to identify the class II DNA sequences involved in the etiopathogenesis of VKH in Mexican Mestizos. This study included 46 VKH patients and 170 controls. 75% were females (mean age at onset of 33.5 years). The disease evolved to chronicity (68%) and 25% of the patients were unresponsive to corticotherapy. DNA typing of HLA-DRB1, DQA1 and DQB1 was done following the 12th International Histocompatibility protocols. VKH was strongly dependent of DRB1 gene; DRB1*04 was found in 78.2% of the patients vs. 50.6% of the controls (p = 0.001). No particular DRB*04 subtype was significantly increased, suggesting that residues E-9 V-11; H-13; H-33 and Y-37 shared by all DR4s are implicated in susceptibility to VKH. However DRB1*0101 (p = 0.009, OR = 4.2) was clearly associated. This allele shares the motif LLEQRRAAG located at position 67-74 and 86 of DRB1 with *0405 associated in Japanese. Two HLA associated mechanisms may be triggering the autoimmune phenomena. One involving critical polymorphic residues expressed in different alleles. Secondly, some peptides may anchor to the conserved residues leaving other sequences to bind to the T cell receptor.

MHC class II sequences of susceptibility and protection in Mexicans with autoimmune hepatitis.

BACKGROUND/AIMS: Autoimmune hepatitis has a genetic background associated with different HLA DRB1 alleles depending on the ethnic group. The aim of this study was to analyse the immunogenetics of type I autoimmune hepatitis in Mexicans. METHODS: Thirty Mexican Mestizo patients and 175 healthy controls were HLA typed as follows: class I antigens were determined by microlymphocytotoxicity and class II typing was done on DNA samples using PCR-SSO and PCR-SSP for DRB1, DQA1 and DQB1 loci. RESULTS: A significant association of autoimmune hepatitis with DRB1*0404 was found, (chi2Y=19.95, pc=0.002, RR=7.71), suggesting the presence of a susceptibility gene located at the DRB1 locus. Resistance was at least partially due to a DQB1 gene, since a significant decrease in DQB1*0301 was also detected (chi2Y=8.21, pc=0.04). Analysis of subgroups according to age at onset showed an association with DRB1*0404 (chi2Y=4.31, p=0.04) in patients with late onset (after 30 years), while DQA1*0501 (chi2Y=5.12, p=0.02) was increased in the early onset group. CONCLUSIONS: The possible mechanism of HLA association is due to "shared epitopes", since DRB1*0404, and those found in other populations namely, DRB1*0401, *0405 and *0301 share almost the same sequence at position 67-72 (LLEQRR, R or K at 71). Valine-86 is also relevant to the age at onset because DRB1*0404 is increased in the patients with an average age at onset of 32. These findings are relevant in determining which peptides in the liver are targets for T cells.