RESUMEN
Inter-individual variability in drug metabolism may result in adverse drug responses. Pharmacogenetic studies have shown that polymorphisms in drug metabolizing enzymes may contribute to this variability. Among these enzymes, CYP3A4 is responsible for metabolizing over 50% of the clinically used drugs. The Brazilian population is composed of people with Native American, European, and African ancestries, and is therefore considered as one of the most intermixed populations in the world. A thorough knowledge of the genetic frequencies of CYP3A4 allelic variants is useful for the establishment of better pharmacological therapies; therefore, the aim of this study was to describe the polymorphic frequencies for CYP3A4 -392A>G (rs2740574) in a sample population from Maranhão, Brazil. Our results showed that 75.1, 21.9, and 3.0% of the individuals expressed the -392AA, -392AG, and -392GG genotypes, respectively. The -392A and -392G alleles were observed in 86.1 and 13.9% of the population, respectively. Our results reiterate the need for a better understanding of the variations in the genotype and allele frequencies of CYP3A4 -392A>G polymorphisms in various Brazilian regions, in order to elucidate the variability in drug response.
Asunto(s)
Citocromo P-450 CYP3A/genética , Inactivación Metabólica/genética , Farmacogenética , Polimorfismo de Nucleótido Simple , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Población Negra , Brasil , Femenino , Expresión Génica , Frecuencia de los Genes , Genotipo , Humanos , Indígenas Sudamericanos , Masculino , Persona de Mediana Edad , Población BlancaRESUMEN
BACKGROUND: Interleukin-6 (IL-6) is an inflammatory mediator linked to nasal polyposis and asthma, with a single nucleotide poly- morphism -174 G/C that seems to promote an inflammatory status. We aimed to analyze the relationship between this poly-morhism and asthmatic nasal polyposis patients. METHODOLOGY: Cross-sectional study to investigate IL-6 - 174 G/C genotypes of 45 nasal polyposis with asthma patients, 63 nasal polyposis-only patients, 45 asthma-only patients and 81 subjects without both diseases. Aspirin intolerance and atopy were main exclusion criteria. IL-6 genotyping was performed using the PCR method with specific primers followed by restriction enzyme analysis, classifying patients in GG, GC or CC genotype. RESULTS: The GG genotype was the most frequent in all inflammatory groups. Less than 40% of controls presented with the GG ge- notype. There were significant differences between inflammatory groups and control group. No significant differences were seen when comparing inflammatory groups to each other, other than between nasal polyposis-only group and asthma-only group. CONCLUSION: The IL-6 74 GG genotype was found more frequently in all inflammatory groups than in controls. This genotype could influence nasal polyposis and asthma, and seems to be more important in the latter.
Asunto(s)
Asma/genética , Interleucina-6/genética , Pólipos Nasales/genética , Polimorfismo de Nucleótido Simple , Alelos , Análisis de Varianza , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Estudios Transversales , Femenino , Genotipo , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas , Estadísticas no ParamétricasRESUMEN
Studies have shown that estrogen replacement therapy and estrogen plus progestin replacement therapy alter serum levels of total, LDL and HDL cholesterol levels. However, HDL cholesterol levels in women vary considerably in response to hormone replacement therapy (HRT). A significant portion of the variability of these levels has been attributed to genetic factors. Therefore, we investigated the influence of estrogen receptor-alpha (ESR1) gene polymorphisms on HDL levels in response to postmenopausal HRT. We performed a prospective cohort study on 54 postmenopausal women who had not used HRT before the study and had no significant general medical illness. HRT consisted of conjugated equine estrogen and medroxyprogesterone acetate continuously for 1 year. The lipoprotein levels were measured from blood samples taken before the start of therapy and after 1 year of HRT. ESR1 polymorphism (MspI C>T, HaeIII C>T, PvuII C>T, and XbaI A>G) frequencies were assayed by restriction fragment length polymorphism. A general linear model was used to describe the relationships between HDL levels and genotypes after adjusting for age. A significant increase in HDL levels was observed after HRT (P = 0.029). Women with the ESR1 PvuII TT genotype showed a statistically significant increase in HDL levels after HRT (P = 0.032). No association was found between other ESR1 polymorphisms and HDL levels. According to our results, the ESR1 PvuII TT genotype was associated with increased levels of HDL after 1 year of HRT.
Asunto(s)
Femenino , Humanos , Persona de Mediana Edad , HDL-Colesterol/sangre , Terapia de Reemplazo de Estrógeno , Receptor alfa de Estrógeno/genética , Estrógenos Conjugados (USP)/uso terapéutico , Acetato de Medroxiprogesterona/uso terapéutico , Polimorfismo Genético/genética , Estudios de Cohortes , HDL-Colesterol/genética , Genotipo , Polimorfismo de Longitud del Fragmento de Restricción , Estudios ProspectivosRESUMEN
Studies have shown that estrogen replacement therapy and estrogen plus progestin replacement therapy alter serum levels of total, LDL and HDL cholesterol levels. However, HDL cholesterol levels in women vary considerably in response to hormone replacement therapy (HRT). A significant portion of the variability of these levels has been attributed to genetic factors. Therefore, we investigated the influence of estrogen receptor-alpha (ESR1) gene polymorphisms on HDL levels in response to postmenopausal HRT. We performed a prospective cohort study on 54 postmenopausal women who had not used HRT before the study and had no significant general medical illness. HRT consisted of conjugated equine estrogen and medroxyprogesterone acetate continuously for 1 year. The lipoprotein levels were measured from blood samples taken before the start of therapy and after 1 year of HRT. ESR1 polymorphism (MspI C>T, HaeIII C>T, PvuII C>T, and XbaI A>G) frequencies were assayed by restriction fragment length polymorphism. A general linear model was used to describe the relationships between HDL levels and genotypes after adjusting for age. A significant increase in HDL levels was observed after HRT (P = 0.029). Women with the ESR1 PvuII TT genotype showed a statistically significant increase in HDL levels after HRT (P = 0.032). No association was found between other ESR1 polymorphisms and HDL levels. According to our results, the ESR1 PvuII TT genotype was associated with increased levels of HDL after 1 year of HRT.
Asunto(s)
HDL-Colesterol/sangre , Receptor alfa de Estrógeno/genética , Terapia de Reemplazo de Estrógeno , Estrógenos Conjugados (USP)/uso terapéutico , Acetato de Medroxiprogesterona/uso terapéutico , Polimorfismo Genético/genética , HDL-Colesterol/genética , Estudios de Cohortes , Femenino , Genotipo , Humanos , Persona de Mediana Edad , Polimorfismo de Longitud del Fragmento de Restricción , Estudios ProspectivosRESUMEN
OBJECTIVE: Apoptosis is an important fail-safe control in human papillomavirus (HPV)-associated carcinogenesis. We tested the hypothesis that the A/G polymorphism at -670 of Fas promoter is associated with an increased risk for cervical cancer, using a matched case-control setting. METHODS: The material in this case-control study consisted of 91 patients with cervical carcinoma and 176 population-based control subjects, recruited between 2002 and 2004; all the ethnic Brazilian women had histologically confirmed cervical carcinoma. Control subjects were age-matched; healthy women who were selected following a negative cervical cytology and normal colposcopy. Fas genotyping was performed using a PCR-RFLP technique. RESULTS: No significant difference existed in the distribution of the Fas polymorphisms (wild, heterozygous, mutant) between the cases and controls. The heterozygous (OR: 4.85, 95% CI: 1.1-22.6) genotypes among the younger (< 48 yrs) cancer patients were almost 5-fold increased, as compared with the wild type. No such increase was observed among the patients older than 48 years. CONCLUSIONS: Our data suggest that 670A/G polymorphism in the promoter region of the death receptor Fas is associated with an increased risk of cervical cancer among Brazilian women under 48 years. The mechanisms would be the inhibition of apoptosis by Fas -670G allele-mediated down-regulation of Fas transcription.
Asunto(s)
Polimorfismo Genético , Regiones Promotoras Genéticas/genética , Neoplasias del Cuello Uterino/genética , Receptor fas/genética , Adulto , Apoptosis , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Humanos , Persona de Mediana Edad , Receptores de Muerte Celular/genéticaRESUMEN
Radiologic breast density is one of the predictive factors for breast cancer and the extent of the density is directly related to postmenopause. However, some patients have dense breasts even during postmenopause. This condition may be explained by the genes that codify for the proteins involved in the biosynthesis, as well as the activity and metabolism of steroid hormones. They are polymorphic, which could explain the variations of individual hormones and, consequently, breast density. The constant need to find markers that may assist in the primary prevention of breast cancer as well as in selecting high risk patients motived this study. We determined the influence of genetic polymorphism of CYP17 (cytochrome P450c17, the gene involved in steroid hormone biosynthesis), GSTM1 (glutathione S-transferase M1, an enzyme involved in estrogen metabolism) and PROGINS (progesterone receptor), for association with high breast density. One hundred and twenty-three postmenopausal patients who were not on hormone therapy and had no clinical or mammographic breast alterations were included in the present study. The results of this study reveal that there was no association between dense breasts and CYP17 or GSTM1. There was a trend, which was not statistically significant (P = 0.084), towards the association between PROGINS polymorphism and dense breasts. However, multivariate logistic regression showed that wild-type PROGINS and mutated CYP17, taken together, resulted in a 4.87 times higher chance of having dense breasts (P = 0.030). In conclusion, in the present study, we were able to identify an association among polymorphisms, involved in estradiol biosyntheses as well as progesterone response, and radiological mammary density.
Asunto(s)
Neoplasias de la Mama/genética , Glutatión Transferasa/genética , Mamografía , Polimorfismo Genético/genética , Receptores de Progesterona/genética , Esteroide 17-alfa-Hidroxilasa/genética , Biomarcadores de Tumor/genética , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Femenino , Genotipo , Humanos , Persona de Mediana Edad , Posmenopausia , Valor Predictivo de las PruebasRESUMEN
Breast cancer is a common disease in Western societies, with an incidence of 46.31/100,000 women/year in Brazil. The tumor suppressor gene TP53 is one of the most studied genes regarding the presence of mutations. Indeed, 50% of all tumors are known to exhibit changes in the TP53 nucleotide sequence due to carcinogenic processes. As to the presence of polymorphism, the TP53 gene is polymorphic at the nucleotide residue 347 (codon 72). In the current study, we examine if this polymorphism is associated with the clinicopathological parameters of breast cancer patients in a Brazilian population. One hundred and thirteen patients with breast cancer were included. The polymorphic region of the TP53 gene was PCR-amplified from genomic DNA obtained from buccal cells. Specific primers for the Pro and Arg allele were used. Correlations of polymorphism with age, staging, nuclear grade, lymph node status, estrogen receptor status and lymphatic and/or blood vessel invasion were evaluated. Statistical analysis was performed using the Fisher's exact test. The frequency of p53 Arg/Arg was 57% and of the heterozygous allele Arg/Pro it was 39%. There was no correlation between polymorphism and clinicopathological parameters. According to our results, the TP53 polymorphism, at the 347 residue, is not associated with any clinicopathological findings of patients with breast cancer.
Asunto(s)
Neoplasias de la Mama/genética , Codón/genética , Polimorfismo Genético/genética , Proteína p53 Supresora de Tumor/genética , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Brasil/epidemiología , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/patología , Cartilla de ADN/genética , Femenino , Genotipo , Humanos , Incidencia , Persona de Mediana Edad , Invasividad Neoplásica , Estadificación de Neoplasias , Reacción en Cadena de la Polimerasa , Pronóstico , Receptores de Estrógenos/análisis , Proteína p53 Supresora de Tumor/análisisRESUMEN
AIMS AND BACKGROUND: The enzyme cytochrome P450 plays an important role in the metabolization and detoxification of various compounds. CYP1A1 is a polymorphic enzyme and some of its alleles have been correlated with an increased risk of developing various types of cancer. The aim of this study was to investigate the incidence of the polymorphism A-->G (Ile462Val, exon 7) in colorectal cancer patients and the correlation of this polymorphism with others risk factors. PATIENTS AND METHODS: 114 Brazilian patients with colorectal cancer were matched by age and sex to 114 healthy individuals. DNA was extracted from peripheral blood and the genotypes of the polymorphisms were assessed by PCR-restriction fragment length polymorphism. RESULTS: In the case group 64 subjects were male, 53 were alcohol users and 68 were smokers. In the control group 61 were male, 67 were alcohol users and 53 smokers. There were 14 subjects with wild-type homozygous A/A, 97 with heterozygous A/G, and 3 with homozygous mutated G/G in the cancer group versus 81 subjects with wild-type homozygous A/A and 33 with heterozygous A/G in the control group. The presence of the G allele (OR 5.14, 95%CI 3.15-10.80) was associated with an increased risk of colorectal cancer (p=0.001). The prevalence of smokers was higher in the cancer group (p=0.047, OR 1.71, 95%CI 1.03-3.11). CONCLUSION: These results suggest a positive association between the A-->G polymorphism and the risk of colorectal cancer. In addition, smoking was also a colorectal cancer risk. We did not find any correlation between this polymorphism and sex, grade of differentiation, stage, or evolution of the disease.
Asunto(s)
Neoplasias Colorrectales/enzimología , Neoplasias Colorrectales/genética , Citocromo P-450 CYP1A1/genética , Polimorfismo de Nucleótido Simple , Adulto , Anciano , Consumo de Bebidas Alcohólicas/efectos adversos , Sustitución de Aminoácidos , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Secuencia de Bases , Brasil , Estudios de Casos y Controles , Neoplasias Colorrectales/etiología , Cartilla de ADN/genética , ADN de Neoplasias/genética , Femenino , Heterocigoto , Homocigoto , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Fumar/efectos adversosRESUMEN
OBJECTIVE: To analyze the participation of glutathione-S-transferase (GST) M1 and T1 polymorphisms associated or not with protein p53 polymorphism at codon 72 and in the presence of HPV in the carcinogenesis of uterine cervix adenocarcinoma. METHODS: Forty-three samples of uterine cervix adenocarcinoma were studied and 86 samples of endocervical cells of women without tumors formed the control group. The presence of HPV was determined in order to genotype the isoforms of p53 at codon 72, GSTM1, GSTM1*0, GSTT1 and GSTT1*0 which were evaluated by the PCR method. RESULTS: HPV was present in 97.67% of the adenocarcinoma cases and in 31.40% of the control group. Statistical analysis showed differences (p = 0.001) and an OR of 113.3 (CI 95%: 13.67-947.14). GSTT1 and GSTT1*0 analysis showed a significant difference between the groups (p = 0.001) with an OR of 4.58 (CI 95%: 2.041-10.28) (p < 0.001) for the presence of GSTT1*0. When it was associated with HPV OR was 6.6 (CI 95%: 0.04-0.50). Analyses of p53 and GSTM1 and GSTM1*0 either alone or associated with HPV were not significant. CONCLUSION: The presence of GSTT1*0 increased the risk for uterine cervix adenocarcinoma development while the allele GSTT1 had a protective action. The other isoforms did not appear to participate in the carcinogenesis of uterine cervix adenocarcinoma.
Asunto(s)
Adenocarcinoma/genética , Alphapapillomavirus/aislamiento & purificación , Glutatión Transferasa/genética , Polimorfismo de Nucleótido Simple/genética , Neoplasias del Cuello Uterino/genética , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Estudios de Cohortes , Femenino , Genes p53/genética , Humanos , Persona de Mediana Edad , Oportunidad Relativa , Adulto JovenRESUMEN
Paracoccidioidomycosis, a systemic mycosis, is rarely diagnosed in its initial phase and can remain latent for up to 40 years. Although PCR is sensitive for the identification of Paracoccidioides brasiliensis (Pb) in different samples, no study using paraffin-embedded human tissue has been published. The size of the amplicon, the fixation method and the time of the storage may affect the reaction. Recently the more sensitive Primer-Extension-Preamplification (PEP)-Nested-PCR has been used for amplification of small samples. Our aims were to detect Pb in paraffin embedded biopsies using (PEP)-Nested-PCR and to correlate the data with histopathological parameters. Analyses were carried out in 107 biopsies from tegument, lymph node, lung and tongue. The fungal DNA was detected in 29.9% of the biopsies by (PEP)-nested-PCR against 5% of Nested-PCR. The positivity correlated with numbers of fungi and fungal viable cells, and there was no correlation with the granuloma pattern.
Asunto(s)
Paracoccidioides/aislamiento & purificación , Paracoccidioidomicosis/microbiología , Paracoccidioidomicosis/patología , Reacción en Cadena de la Polimerasa , Biopsia , ADN Bacteriano/análisis , Humanos , Paracoccidioides/genéticaRESUMEN
INTRODUCTION: The objective of this study was to evaluate the effect of tibolone on cytochrome oxidase I (COX I), beta-2-microglobulin (B2M) and vascular endothelial growth factor (VEGF) gene expression in the lower urinary tract of castrated rats. These genes are related to cell energy, cellular immunity and vascularization processes. METHODS: Fifty adult castrated rats remained at rest for 28 days. Thereafter they were randomly divided into two groups of 25 animals each. The lower urinary tract (bladder and urethra) was extracted in animals of one group and the other group received tibolone at a dose of 0.25 microg/animal/day for another 28 days followed by removal of the lower urinary tract. Total RNA was extracted from animals of both groups, forming two pools. After RT-PCR (reverse transcriptase polymerase chain reaction), expression of COX I, B2M and VEGF genes was evaluated by agarose gel electrophoresis, visualized by UV illumination. RESULTS: Expression of the three genes (COX I, B2M and VEGF) was greater in the group treated with tibolone. CONCLUSION: The use of tibolone increases the expression of COX, B2M and VEGF genes in the lower urinary tract as compared with that in castrated rats.
Asunto(s)
Complejo IV de Transporte de Electrones/efectos de los fármacos , Moduladores de los Receptores de Estrógeno/farmacología , Norpregnenos/farmacología , Sistema Urinario/efectos de los fármacos , Factor A de Crecimiento Endotelial Vascular/efectos de los fármacos , Microglobulina beta-2/efectos de los fármacos , Animales , Castración , Expresión Génica/efectos de los fármacos , Ratas , Ratas WistarRESUMEN
Our purpose was to identify tamoxifen (TAM) responsive genes after 30 days of TAM treatment in tumor tissues obtained from women with breast cancer using microarray expression analysis. In our study, we identified 12 candidates to be considered as tamoxifen-modulated genes. Among them, we selected two candidates the TEGT BI-1 (testis enhanced gene transcript Bax Inhibitor-1) and the CD63 gene in order to further confirm their differential expression under tamoxifen effects. We observed that both were down-regulated in tumor tissues of patients during TAM treatment. TEGT is able to inhibit the expression of Bax, which is known to promote apoptosis. On the other hand, CD63 encodes a cell membrane protein and it seems to be involved in mechanisms of platelet activation, cell adhesion and cell motility. We therefore hypothesize that TAM would be able to modulate tumor growth by down-regulating genes involved in mechanisms such as cell cycle control, tumor invasion and metastasis.
Asunto(s)
Neoplasias de la Mama/genética , Carcinoma Ductal de Mama/genética , Antagonistas de Estrógenos/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Tamoxifeno/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Neoplasias de la Mama/cirugía , Carcinoma Ductal de Mama/tratamiento farmacológico , Carcinoma Ductal de Mama/patología , Carcinoma Ductal de Mama/cirugía , Antagonistas de Estrógenos/uso terapéutico , Femenino , Humanos , Análisis por Micromatrices , Análisis de Secuencia por Matrices de Oligonucleótidos , Proteínas Proto-Oncogénicas/biosíntesis , Proteínas Proto-Oncogénicas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tamoxifeno/uso terapéuticoRESUMEN
Granzyme B (GrB) is a serine protease synthesized in T lympocytes (CTL), released after T-cell activation resulting from exogenous stimulation. With perforin, GrB discharges apoptotic signals to a target cell and therefore constitutes a marker to identify activated CTL. We aimed to quantify GrB expression by immunohistochemistry staining in 12 tissue fragments of cervical carcinoma, 33 cervical intraepithelial neoplasias treated by LLTEZ and nine cervical pieces without disease. Activated cytotoxic lymphocyte mean values (20 HPF-400x) in both epithelial and stromal pars were 7.11 cells in tissue without neoplasia, 33.45 cells in cervical intraepithelial neoplasia and 139.75 cells in carcinoma samples, with a statistical difference between them. Comparative analysis in the CIN group showed an expressive difference between cases with disease recurrence (19.28 cells) and without recurrence (37.26 cells). Thus, the relation between number of activated CTLs found at the moment of treatment and clinical evolution determined in this study, suggest GrB use as a prognostic marker.
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Biomarcadores de Tumor/metabolismo , Recurrencia Local de Neoplasia/metabolismo , Serina Endopeptidasas/metabolismo , Displasia del Cuello del Útero/metabolismo , Neoplasias del Cuello Uterino/metabolismo , Adulto , Estudios de Casos y Controles , Femenino , Granzimas , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Valor Predictivo de las Pruebas , Pronóstico , Neoplasias del Cuello Uterino/patología , Displasia del Cuello del Útero/patologíaRESUMEN
Open reading frame expressed sequences tags (ORESTES) differ from conventional ESTs by providing sequence data from the central protein coding portion of transcripts. We generated a total of 696,745 ORESTES sequences from 24 human tissues and used a subset of the data that correspond to a set of 15,095 full-length mRNAs as a means of assessing the efficiency of the strategy and its potential contribution to the definition of the human transcriptome. We estimate that ORESTES sampled over 80% of all highly and moderately expressed, and between 40% and 50% of rarely expressed, human genes. In our most thoroughly sequenced tissue, the breast, the 130,000 ORESTES generated are derived from transcripts from an estimated 70% of all genes expressed in that tissue, with an equally efficient representation of both highly and poorly expressed genes. In this respect, we find that the capacity of the ORESTES strategy both for gene discovery and shotgun transcript sequence generation significantly exceeds that of conventional ESTs. The distribution of ORESTES is such that many human transcripts are now represented by a scaffold of partial sequences distributed along the length of each gene product. The experimental joining of the scaffold components, by reverse transcription-PCR, represents a direct route to transcript finishing that may represent a useful alternative to full-length cDNA cloning.
Asunto(s)
Etiquetas de Secuencia Expresada , Genoma Humano , Sistemas de Lectura Abierta , Transcripción Genética , HumanosRESUMEN
Transcribed sequences in the human genome can be identified with confidence only by alignment with sequences derived from cDNAs synthesized from naturally occurring mRNAs. We constructed a set of 250,000 cDNAs that represent partial expressed gene sequences and that are biased toward the central coding regions of the resulting transcripts. They are termed ORF expressed sequence tags (ORESTES). The 250,000 ORESTES were assembled into 81,429 contigs. Of these, 1, 181 (1.45%) were found to match sequences in chromosome 22 with at least one ORESTES contig for 162 (65.6%) of the 247 known genes, for 67 (44.6%) of the 150 related genes, and for 45 of the 148 (30.4%) EST-predicted genes on this chromosome. Using a set of stringent criteria to validate our sequences, we identified a further 219 previously unannotated transcribed sequences on chromosome 22. Of these, 171 were in fact also defined by EST or full length cDNA sequences available in GenBank but not utilized in the initial annotation of the first human chromosome sequence. Thus despite representing less than 15% of all expressed human sequences in the public databases at the time of the present analysis, ORESTES sequences defined 48 transcribed sequences on chromosome 22 not defined by other sequences. All of the transcribed sequences defined by ORESTES coincided with DNA regions predicted as encoding exons by genscan. (http://genes.mit.edu/GENSCAN.html).
Asunto(s)
Cromosomas Humanos Par 22 , Transcripción Genética , Etiquetas de Secuencia Expresada , Perfilación de la Expresión Génica , Humanos , Sistemas de Lectura AbiertaRESUMEN
The authors investigate the differences between the angiogenesis that occurs in malignant and benign breast tumours (10 specimens of invasive ductal carcinoma and 10 specimens of fibroadenoma) as well as in the adjacent breast stroma of these women highlighting the microvessels by staining their endothelial cells for factor VIII immunohistochemically. The number of vessels counted in invasive ductal carcinoma was significantly higher than the number of vessels counted in fibroadenoma and in the adjacent breast stroma. There was no difference between the number of vessels counted in the fibroadenoma and its adjacent stroma. Even though the patients with invasive ductal carcinoma showed a adjacent stroma with a higher number of vessels, the difference was not significant when compared with the adjacent stroma obtained from patients with fibroadenoma.