Cáncer gástrico y regulación del crecimiento tumoral: estudio de marcadores de proliferación celular y del complejo proteínas p53/p21WAF1/CIP1/mdm-2 / Gastric cancer and tumor growth regulation: study of cell proliferation markers and protein complex p53/p21WAF1/CIP1/mdm-2

Gastric cancer and tumor growth regulation. Study of cell proliferation markers and protein complex p53/p21WAF1/CIP1/mdm-2. Background: p53/p21WAF1/CIP1 and mdm-2 proteins play an important role in cell cycle regulation. The study of the pathogenesis of gastric cancer is important to understand how these tumors progress during their natural history. Aim: To study the relationship between the immunohistochemical expression of p53/p21WAF1/CIP1 and mdm-2 and cell proliferation in gastric cancer. Material and methods: Fifty one gastrectomy specimens with gastric cancer were studied using immunohistochemistry for p53/p21WAF1/CIP1 and mdm-2. Cell proliferation was determined by immunolabelling with PCNA and Ki67 antigens. Mitosis figures were counted in 10 high power microscopic fields. Results: Patients from whom gastric cancer specimens were obtained had a mean age of 59.3 years. Ki67 and mitosis counting showed the highest correlation index with proliferation indexes studied. No correlation was found between the expression of protein complex p53/p21WAF1/CIP1 and mdm-2 and morphological characteristics of gastric tumors. Mdm-2 protein overexpression was the only marker that showed an independent correlation with cell proliferation. Moreover, mdm-2 positive tumors showed the highest proliferation indexes when p53 was not immunohistochemically over-expressed, as determined by PCNA labelling index. Conclusions: In gastric cancer, a direct correlation between mdm-2 overexpression and cell proliferation was observed. Moreover, the fact that mdm-2 positive tumors showed the highest cell proliferation when p53 was not overexpressed, entitles us to hypothesize that mdm-2 overexpression could play a major role in gastric carcinogenesis

Helicobacter pylori y gastritis crónica: relación entre infección y actividad inflamatoria en población de alto riesgo de cáncer gástrico / Helicobacter pylori and chronic gastritis: relationship between infection and inflammatory activity in a high risk population for gastric cancer

Background: Helicobacter pylori has been involved in gastric epithelial cell damage and gastric gland loss or atrophy. Aims: to evaluate role of Helicobacter pylori infection in acute and chronic changes of chronic gastritis in a high gastric cancer-risk population. Material and methods: 200 patients with chronic gastritis were selected from pathological files of Temuco Hospital. A complete histopathological protocol was fulfilled considering the presence of infection by Helicobacter pylori-like-organism (HLO), acute and chronic inflammatory infiltrate, epithelial cell damage and epithelial cell regeneration. Results: 82 percent of patients showed infection by HLO. Moreover, this infection reached a frequency of 92.7 percent in gastric ulcer patients and 94.4 percent in duodenal ulcer patients. A statistically significant positive correlation was found between HLO infection and polymorphonuclear infiltrate, Iymphocytic infiltrate, mucus depletion and epithelial regenerative activity. There was not a statistical correlation between HLO infection and atrophy. Finally, 90 percent of patients with multifocal atrophic gastritis and 100 percent of patients with diffuse antral gastritis had HLO infection. Conclusions: HLO gastric infection frequently caused acute inflammatory changes in gastric mucosa with chronic gastritis. Sometimes these changes were severe, with marked polymorphonuclear migration throughout epithelium and severe epithelial cell damage. Recovery of these changes could be considered as a goal in Helicobacter pylori eradication therapy decision

Inestabilidad microsatelital y pérdida de la heterocigocidad en lesiones neoplásicas y preneoplásicas gástricas / Microsatellite instability and loss of heterozygosity in neoplastic and preneoplastic gastric lesions

Gastric cancer is the leading cause of cancer deaths in the general population in Chile, with mortality rates as high as 33.7 per 105 in males in the IX region. A chain of genetic and morphological events precedes the intestinal type of gastric carcinoma. One of them is the called multifocal atrophic gastritis often associated with intestinal metaplasia. Aim: To study the frequency of microsatellite instability (MSI) and loss of heterocigozity (LOH) in neoplastic and preneoplastic lesions of gastric carcinoma, especially intestinal metaplasia. Material and methods: Ninety four gastric cancer biopsies were studied using laser capture microdissection, to obtain well defined cell populations from paraffin-embedded tissues: lymphocytes (control DNA), intestinal metaplasia and gastric cancer areas. Primer flanking microsatellite 15 highly polymorphic regions were used to study MSI and LOH. Radioactive PCR products were electrophoresed and exposed for autoradiography. Results: LOH was observed in 83% of gastric carcinomas and in 54% areas containing intestinal metaplasia. The most commonly altered regions were the CA repeat associated with the p53 gene and the 3p21 region. High grade MSI was observed in 11.7% of gastric cancer preparations and 17% of intestinal metaplasia associated to cancer with MSI-H phenotype. Conclusions: MSI and LOH were frequently observed in intestinal metaplasia glands in patients with gastric carcinoma. The frequency of MSI-H phenotype in gastric patients was slightly lower than the one described in sporadic colorectal cancer not associated to HNPCC. The high incidence of genetic lesions in intestinal metaplasia area, support the idea that intestinal metaplasia is a genetically highly unstable cell population (Rev Méd Chile 2003; 131: 1227-36).

Estudio morfométrico de biopsia de intestino delgado / Biopsy morphometric study of small intestine

Dentro del estudio clínico de pacientes con malabsorción intestinal se considera la alternativa de practicar una biopsia de intestino delgado. Según algunos autores, el examen histopatológico implica variabilidad interpersonal e intrapersonal, lo cual se corregiría al efectuar estudios morfométricos. En nuestro estudio se muestra el uso de instrumentos de cartografía (curvímetro y planímetro) en la medición de áreas y perímetros, más el uso de índices matemáticos que permiten reagrupar a las biopsias y pacientes en grados diversos de aplanamiento vellositario. Asimismo, los resultados permitieron sugerir tres categorías para el índice mocoso (mayor o igual que 3, de 1,6 a 2,9 y menor o igual a 1,5) y tres para el índice perímetro área (mayor o igual a 0,2 de 0,11 a 0,19 y menor o igual a 0,1), con concordancia estadísticamente significativa (coeficiente de Pearson de 0,8084). El análisis morfométrico permitió detectar pacientes en cuya biopsia el grado de alteración era superior al originalmente descrito. Finalmente, se muestra el grado de variabilidad interpersonal del examen de la biopsia con microscopía de luz convencional con valor Kappa global igual a 0,5254 (desde 0,169 para el grado atrofia parcial leve hasta 0,814 para atrofia subtotal). El interés reside en el costo de instalación y funcionamiento de esta técnica, la cual se ubica muy por debajo de los instrumentos tradicionales de morfometría digital

Mutación del gen p53 en el cáncer de la vesícula biliar / P53 gene mutation in gallbladder cancer

Background: Gallbladder cancer frequency and mortality renders it one of the most important neoplastic diseases in Chile. P53 tumor suppressor gene has been studied in most types of cancer, but there is scarce information about it in gallbladder cancer. Aim: To study the frequency of P53 gene mutation in gallbladder cancer in the ninth region of Chile. Material and methods: In 25 pathological samples of gallbladder cancer, the direct amplification and sequencing of p53 gene exons 5,6,7,8-8 was possible. Results: Seventeen punctual mutations were observed in 13 cases (52 percent). There were 10 transitions, 5 transversions, one insertion (codon 194) and one deletion (codon 186). Eight cases had mutations in exon 5, six had mutations in exon 6, two had mutations in exon 7 and one had mutations in exons 8-9. In 14 of 25 cases, gene p53 protein was positive. When immunohistochemical expression of gene p53 protein was positive in more than 20 percent of cells, there was a high correlation between genetic alterations and immunohistochemical expression of the protein, with a specificity, sensitivity, positive and negative predictive values over 80 percent. Conclusions: P53 gene mutation is observed in a high proportion of gallbladder cancers at it can be accurately detected with conventional immunohistochemical techniques. The importance of this gene in the genesis of this carcinoma should be determined studying preneoplastic lesions and early carcinomas

Mutación del gen p53 en el cáncer de colon y recto / P53 gene mutation in colorectal cancer

Background: Genetic events associated to colorectal carcinoma are well characterized, but there is scanty information about this issue in Chilean subjects. Aim: To determine the frequency and distribution of exons 5, 6, 7, 8 and 9 mutations and the immunohistochemical expression of p53 gene in biopsy samples of colorectal carcinoma. Material and methods: p53 gene exons 5, 6, 7, 8 and 9 were directly sequenced in 42 biopsy samples of colorectal carcinoma. Immunohistochemical expression of p53 was determined in 35 samples. Results: Thirty one discrete mutations (12 transitions, 11 transversions and 8 insertions) were observed in 21 samples (60 percent). Nine samples had mutations in exon 5, twelve samples had mutations in exon 6, seven samples had mutations in exon 7 and three samples had mutations in exons 8 and 9. Immunohistochemical expression of p53 protein was observed in 18 of 35 cases. There was a high correlation between the genetic alteration and immunohistochemistry, when p53 was expressed in more the 20 percent of cells. The positive and negative predictive values of p53 expression were 87 and 80 percent respectively. There was a non significant lower mortality among patients with mutations in their biopsies. Conclusions: These results confirm the involvement of p53 gene mutations in colonic carcinogenesis. Immunohistochemical methods for the detection of p53 protein have a high predictive value

Carcinoma incipiente de la vesícula biliar: estudio clínico patológico y pronóstico de 196 casos / Clinical and pathological features of early gallbladder carcinoma

Background: There is little information about the behavior of early gallbladder carcinoma. Aim: To report the clinical and pathological features of 196 patients with early gallbladder carcinoma. Material and methods: All patients with gallbladder cancer diagnosed between 1988 and 1997 were reviewed. In 703 of 829 patients, there was information about clinical features and follow up, and were included in this study. All gallbladders were subjected to a complete mapping. When neoplastic cells involved only the mucosa or muscular layer, the tumors were considered as early. Results: One hundred ninety six patients had an early carcinoma (161 women, aged 57.5 years and 35 male, aged 63.4 years). One hundred twenty eight tumors were located in the mucosa and 68 in the muscular layer. Patients with tumors involving the mucosa were younger than those with tumors involving the muscular layer. All tumors were adenocarcinomas, 66 per cent were well differentiated and 32 per cent moderately differentiated. Tumors were not visible macroscopically in 132 cases. Five and 10 years survival was 92 per cent. Subjects of less than 40 years old had a 100 per cent survival at 5 years. A hepatic and lymph node resection was done in 12 patients with tumors infiltrating the muscular layer but in only one, the tumor infiltrated the liver. No difference in survival was observed when a simple cholecystectomy or radical surgery was done. Conclusions: Nearly 25 per cent of gallbladder carcinomas can be classified as early and its diagnosis requires a directed study. Simple cholecystectomy is curative for this type of gallbladder cancer

Expresión de CD44 HCAM en el carcinoma subseroso de la vesícula biliar / CD44 HCAM expression in subserous gallbladder carcinoma

Background: HCAM or CD44 is a multifunctional cell adhesion molecule, related to cell-cell, cell-extracellular matrix interactions and involved in tumor invasion. Aim: To study the importance of CD44 expression in subserous gallbladder carcinoma. Material and methods: One hundred five samples (93 female) of subserous gallbladder carcinoma and 33 non tumoral gallbladder were studied. CD44 was stained using the streptavidine-biotin technique, using human anti CD44 antibodies. Eighty subjects with carcinoma were followed for a period up to 105 months. Results: Mean age of patients was 62,6 years old, all tumors were adenocarcinoma, all were silent and 13 percent were well differentiated. CD44 was expressed in all controls and in 91 percent, the expression was normal. In 57 percent of cancer samples, CD44 expression was abnormal, in 50 percent it was less expressed and in 24 percent, it was not expressed. No differences in CD44 expression was observed between mucosa from control samples and mucosa adjacent to the tumor or superficial or deep tumoral areas. Global five years survival was 40 percent. No significant differences in survival were observed in those tumors with a lower of absent CD44 expression. Six patients with a higher expression died before 18 months of follow up. Conclusions: Nearly 50 percent of subserous gallbladder carcinomas show an abnormal CD44 expression

Mutación puntual del gen supresor de tumores TP53 en lesiones preneoplásicas y neoplásicas del estómago / Mutations of TP53 suppressor gene in pre-neoplastic and neoplastic lesions of the stomach: cross-sectional study in a high risk region

Background: In the current model for the development of gastric cancer, regions of multifocal atrophic gastritis give rise to intestinal metaplasia, dysplasia and finally, adenocarcinoma. Aim: To study the frequency and characteristics of TP53 gene mutations in preneoplastic and neoplastic lesions of the stomach. Material and methods: DNA sequencing of the TP53 gene was performed in 46 patients with gastric carcinoma. Normal mucosa, intestinal metaplasia and invasive adenocarcinoma tissues were obtained by scraping 6-Ám histological sections from formalin-fixed and paraffin-embedded tissue. Results: DNA sequencing of exons 5-9 of the TP53 gene demonstrated a mutation in 31 percent of patients. These findings were seen both in tumoral tissue (13 cases) and in intestinal metaplasia (2 cases). Most mutations were found in exons 5 and 8, and the majority of them were transitions (10 out of 19 mutations). Discussion: Patients with gastric cancer showed a frequency of TP53 mutations similar to that previously communicated in populations with low gastric cancer risk. Moreover, there was a predominance of transitions, genetic alterations that are identified with carcinogenesis associated with N-nitrosamine compounds. Finally, mutations of TP53 gene were detected in areas of intestinal metaplasia

Relación de la genotipificación de Helicobacter pylori con la forma e intensidad de la gastritis en población adulta portadora de patología gástrica benigna / Association between helicobacter pylori genotype and the severity of gastritis in infected adults

Background: The damaging capacity of Helicobacter pylori is variable and depends, in part, on its genetic polymorphism. Aim: To study H pylori genes vacA, cagA and iceA and the relationship of these genotypes with the features of acute damage in chronic gastritis. Material and methods: Gastric endoscopic biopsies were obtained in 75 adults for pathological study and genetic typification of H pylori by specific PCR. Results: In only 64 cases, complete information was available. In 53 of these, there was H pylori infection demonstrated by PCR. Twenty one percent had infection by two or more H pylori strains, vacA gene had genotypes s2/m2, s1/m1 and s1/m2 in 36, 25 and 8% of cases respectively, cagA gene was present in 49% of infected patients. iceA gene had genotypes iceA 1 ad iceA 2 in 15 and 60% of patients respectively. The presence of cagA or alleles s1/m1 and s1/m2 of vacA gene was directly correlated with polymorphonuclear infiltration and the severity of epithelial damage. The genotype s2/m2 of vacA gene was significantly associated with a milder or absent mucosal damage. No association was found between iceA alleles and the pathological features of gastritis. Conclusions: Alleles of vacA and cagA genes of H pilory are associated with the severity of gastric mucosal damage.

Hidatidosis periapendicular simulando apendicitis aguda / Acute appendicitis and hepatic echinococcosis

La hidatidosis hepática es una entidad bien conocida. Los quistes hidatídicos pueden ubicarse también en otros sitios del abdomen y simular afecciones de otros órganos. Se describe el caso de una niña en edad escolar cuyas manifestaciones clínicas correspondían a los de apendicitis aguda. El diagnóstico de hidatidosis se hizo durante el examen anatomopatológico del apéndice extirpado que, estando indemne, tenía en el mesoapéndice membranas hidatídicas e intensa reacción inflamatoria. Los exámenes serológicos (ELISA) dieron resultados positivos para IgG e IgE es específicos (IgE total: 1 487 Ul/ml) y en la ultrasonografía abdominal postoperatoria se detectaron tres quistes hidatídicos hepáticos

Gen supresor de tumores p53 en neoplasias digestivas / p53 tumor supresor gene in digestive cancer

Malignant diseases of the digestive tract cause more than 50 percent of deaths due to cancer in Chile. There is a high incidence of gastric and gallbladder cancer and an increasing frequency of colorectal cancer. P53 tumor suppressor gene has a great importance in carcinogenesis and its alterations are specially important in digestive tract tumors such as colorectal cancer. There is contradictory evidence about the frequency of p53 gene or protein alterations or their biological significance. There is little information about p53 in Chile and it is mostly limited to immunohistochemical studies. This revision analyzes the frequency of p53 alterations in digestive tract tumors in Chile, using immunohistochemical and molecular biology methods. A special emphasis is given to the prognostic importance of this gene

Hallazgos en reintervenciones quirúrgicas por cáncer de la vesícula biliar en pacientes con y sin quimio-radiación preoperatoria / Pathological findings in surgical reinterventions for gallbladder cancer in patients with and without preoperative chemo and radiotherapy

Background: The usefulness of surgery in the treatment of gallbladder cancer has not been clearly established. The benefits of chemo and radiotherapy are similarly dubious. Aim: To report the pathological findings in patients subjected to surgical reinterventions for gallbladder cancer. Patients and methods: We report 54 patients with gallbladder cancer that were subjected to a second surgical intervention for resection of liver segments IVb and V and lymph nodes corresponding to the liver hilar, portal, peripancreatic, celiac artery and periaortic territories. Thirteen of these patients were subjected to preoperative chemo-radiotherapy (4500 Gy and 5-fluouracil 500 mg/m2). Results: Lymph node metastases were found in 25 and 38 percent, and liver metastases in 25 and 28 percent of patients with or without chemo-radiotherapy respectively. The most frequent pathological findings attributed to radiation in the liver were fatty infiltration in 75 percent of cases, vascular transformation in 83 percent of cases and minimal periportal lymphocyte infiltration in 40 percent of cases. Lymph nodes were atrophic in 67 percent of cases and had foci of cortical necrosis in 46 percent of cases. Three cases had regional lymph node and liver metastases. Most tumor cells were viable. Conclusions: No differences in the number of lymph node or liver metastases were observed between patients with and without chemo-radiotherapy. No effect of the treatment on residual tumor was observed either

Elementos morfológicos pronósticos en el cáncer de la vesícula biliar / Morphological prognostic factors in gallbladder cancer

Background: The exact survival rates and prognostic factors of gallbladder cancer are still incompletely known. Aim: To report the actuarial survival of patients with gallbladder cancer. Material and methods: Six hundred thirty seven women, aged 59 years old as a mean and 108 men, aged 64 years old as a mean, with gallbladder cancer are reported. Patients were followed for up to 150 months. Results: Two hundred twenty four patients had an early and 521 had an advanced carcinoma. Overall survival was 38 percent at ten years. Sex or ethnic origin did not influence survival. Early tumors had a 92 percent survival at 10 years whereas the survival of advanced tumors was 16 percent at 5 years. Subserous tumors had a 5 years survival of 32 percent whereas serous tumors had a 5 years survival of 11 percent. Well-differentiated advanced tumors had a significantly better survival than moderately or poorly differentiated tumors. Vascular or lymphatic infiltration was also associated to a lower survival. All patients with advanced tumors and vascular infiltration died before 5 years. Conclusions: Tumor infiltration and differentiation degree were the most important prognostic independent factors in gallbladder cancer

Quiste simple yuxtatiroídeo: análisis del posible origen de la lesión / Simple juxtathyroid cyst: analysis of the possible origin of the injury

We report a 34 years old female who presented a simple juxtathyroid cyst. Its content was translucent with a mPTH concentration 30 higher than in blood. This finding lead to the suspicion of a parathyroid cyst; however there were no laboratory evidence of hyperparathyroidism. Two years later and after repeated needle drainages, a surgical cystectomy was made. The immunohistochemical study of the samples was intensely positive for synaptophysis, a parathyroid tissue marker. Surprisingly, thyroglobulin was also found in some cyst wall cells

Determinación del contenido de ADN en tumores de glándulas salivales / Determination of DNA content of salivary gland tumors

Background: DNA content determination is a useful tool in the characterization of different malignant tumors. Aim: to measure DNA content in cells of salivary gland tumors as adjunct to histological diagnosis, correlatting morphologic and biological features of these tumors. Material and methods: from the archives of the pathology service of a general hospital, 21 salivary gland tumors, 15 pleomorphic adenomas, 3 mucoepidermoid carcinomas and 3 cystic adenoid carcinomas were seleced. DNA content was determined in the histological samples using a flow cytometric DNA analysis. Results: all pleomorphic adenomas had a normal or diploid DNA content. Fifty percent of malignant tumors had an aneuploid DNA content (1 mucoepidermoid carcinoma and 2 cystic adenoid carcinomas). Conclusions: DNA determination may help in the histological diagnosis of salivary gland tumors. The presence of aneuploidy suggests malignity

Expresión de la proteína del gen Bcl-2 en tumores de glándulas salivales / Gene Bcl-2 protein expression in salivary gland tumors

Background: Salivary gland tumors have heterogeneous pathological features. Oncogene Bcl-2 product expression inhibits apoptosis and therefore is important for tumor proliferation. Aim: To assess the immunohistochemical gene Bcl-2 protein expression in salivary gland tumors. Material and methods: Twenty seven salivary gland tumors were selected from the archives of the Pathology Department of Temuco Regional Hospital. There were 20 pleiomorphic adenomas, 4 cystic adenoid carcinomas and three mucoepidermoid carcinomas. Immunohistochemical gene Bcl-2 protein expression was determined in paraffin included pathological slices. Results: All pleiomorphic adenomas expressed the protein, specially in tubulo ductal structures, solid and trabecular areas. All cystic adenoid carcinomas expressed the protein in myoepithelial cells. Two mucoepidermoid carcinomas were positive, only in the epidermoid areas. Conclusions: immunohistochemical gene Bcl-2 protein was expressed in virtually all benign and malignant salivary gland tumors. This observation suggest an important role of this protein in the development of these tumors

Expresión de la proteína del gen supresor de tumores p53 en el carcinoma de próstata / Expression of the supressor gene protein of p53 tumors in prostatic carcinoma

El cáncer de la próstata es una de las neoplasias más frecuentes en hombres mayores de 50 años. La mutación y expresión del gen supresor de tumores p53 ha sido demostrado en la carcinogénesis de múltiples neoplasias y en alrededor del 40 por ciento de los cánceres de la próstata. El objeto de este trabajo es determinar la frecuencia de la expresión del gen p53 en el carcinoma prostático. Se estudia la expresión de la proteína p53 en 35 carcinomas prostáticos mediante la técnica de inmunohistoquímica con anticuerpo monoclonal. Los pacientes se distribuyeron por etapas clínicas: Etapa A = 4 casos; Etapa B = 5 casos; Gleason entre 4 y 7 y el 16 por ciento entre 8 y 10. El promedio de edad fue 70,7 años (límites 53-85 años). No se observó tinción positiva en ninguno de los controles ni en los tumores en etapas A y B. Se observó tinción positiva de la proteína del gen p53 en 11 de los 35 casos (31,4 por ciento), 17 por ciento en los en Etapa C y un 64,2 por ciento tumores en los en Etapa D (p = 0,01). No se observó diferencia respecto del índice de Gleason aun cuando los tumores mejor diferenciados presentaron menor positividad. Nuestros resultados muestran que la proteína del gen supresor de tumores p53 no guarda relación con el índice de Gleason y sólo se observa en tumores avanzados, especialmente en la Etapa D, y su determinación puede contribuir significativamente a una mejor evaluación preoperatoria de los pacientes

Antígeno nuclear de proliferación celular (PC10) en pacientes con síndrome de malabsorción: estudio comparativo con parámetros morfométricos / Proliferating cell nuclear antigen (PCNA) in patients with malabsorption syndrome: comparative study with morphometric parameters

The study of small bowel mucosa is routine in the study of patients with malabsorption. We report 16 children aged from 8 months to 6 years old (2 with giardiasis, 8 with primary malnutrition and 5 with celiac diasease) in whom a morphometric and PCNA immunostaining was performed in the small intestinal biopsy. Positively for PCNA was found in the lower portion of the crypts reaching 156 µm of heigh in patients with giardiasis, 103 µm in primary malnutrition and 182 µm in celiac dosease (p<0.01 compared to primary malnutrition). A negative and significant correlation was found between the degree of architectural disorder (expressed the mucosal index) and the proliferative portion of the crypts (expressed as the percentage of PCNA(+) crypts. We propose these methods as complements to the small bowel mucosa histopathological study in the diagnosis of celiac disease, to assess the degree of architectural disorder and the proliferative activity

Expresión de una proteína relacionada al receptor de estrógeno (p29), en carcinoma primario de la mama: análisis metodológico, anatomoclínico y del contenido de ADN / Expression of a estrogen related protein (p29) in primary breast carcinoma: methodological, anatomoclinical and DNA contents analysis

The aim of this work was to assess the immunohistochemical detector of a estrogen receptor related protein (p29) in 48 histological samples of primary mammary carcinoma and its relationship to clinical, morphological and ADN content parameters. p29 protein was positive in 62.5 per cent of samples. Over 50 per cent of samples had moderate or intense immunohistochemical staining (staining index over 16) and 77 per cent has a heterogenous expression of p29 protein. Sevently six per cent of p29 positive and 53 per cent of p29 negative tumors had a proliferation fraction over 10 per cent (determined by the fraction with flux cytometry). No relationship between p29 expression and the analyzed anatomoclinical variables was found. These results highlight this immunohistochemical method as an alternative to more complex and difficult biochemical thechniques. On the other hand the good results obtained in formalin fixed tissues allow retrospective studies in mammary carcinoma samples