Gastric Polyp Growth during Endoscopic Surveillance for Esophageal Varices or Barrett's Esophagus.

BACKGROUND: We recently observed patients with chronic liver disease (CLD) or chronic reflux symptoms (CRS) who developed gastric polyps (GPs) while undergoing surveillance gastroscopies for the detection of esophageal varices or Barrett's esophagus, respectively. OBJECTIVES: To identify risk factors for GP growth and estimate its growth rate. METHODS: GP growth rate was defined as the number of days since the first gastroscopy (without polyps) in the surveillance program, until the gastroscopy when a GP was discovered. RESULTS: Gastric polyp growth rates in CLD and CRS patients were similar. However, hyperplastic gastric polyps (HGPs) were detected more often (87.5% vs. 60.5%, P = 0.051) and at a higher number (2.57 ± 1.33 vs. 1.65 ± 0.93, P = 0.021) in the CLD patients. Subgroup analysis revealed the following findings only in CLD patients with HGPs: (i) a positive correlation between the GP growth rate and the patient's age; the older the patient, the higher the GP growth rate (r = 0.7, P = 0.004). (ii) A negative correlation between the patient's age and the Ki-67 proliferation index value; the older the patient, the lower the Ki-67 value (r = -0.64, P = 0.02). No correlation was detected between Ki-67 values of HGPs in CLD patients and the presence of portal hypertension, infection with Helicobacter pylori, or proton pump inhibitor use. CONCLUSIONS: In comparison with CRS patients, CLD patients developed HGPs more often and at a greater number. Young CLD patients may have a tendency to develop HGPs at a faster rate than elderly CLD patients.

Endoscopic and histologic characteristics of serrated lesions.

In recent years, a second pathway for colonic carcinogenesis, distinct from the adenomatous pathway, has been explored. This is referred to as serrated pathway and includes three types of polyp, characterised by a serrated appearance of the crypts: hyperplastic polyps (HP), sessile serrated adenomas (SSA) or lesions, and traditional serrated adenomas. Each lesion has its own genetic, as well as macroscopic and microscopic morphological features. Because of their flat aspect, their detection is easier with chromoendoscopy (carmin indigo or narrow-band imaging). However, as we show in this review, the distinction between SSA and HP is quite difficult. It is now recommended to resect in one piece as it is possible the serrated polyps with a control in a delay depending on the presence or not of dysplasia. These different types of lesion are described in detail in the present review in general population, in polyposis and in inflammatory bowel diseases patients. This review highlights the need to improve characterization and understanding of this way of colorectal cancerogenesis.

Growth hormone receptor expression is up-regulated during tumorigenesis of human colorectal cancer.

BACKGROUND: The aim of the present study was to analyze the expression of growth hormone receptor (GHR) in the colorectal adenoma-carcinoma sequence to determine whether its expression correlates with the various stages of cancer transformation. METHODS: GHR distribution was assessed by immunohistochemistry and semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) in normal, premalignant, and malignant colorectal lesions. RESULTS: Most of the normal mucous tissues and hyperplastic polyps showed no or weak immunoreactivity for GHR. In contrast, most of the adenoma and adenocarcinoma samples reacted strongly or moderately with monoclonal GHR antibodies. In RT-PCR, amplified fragments of the expected sizes (247bp) were detected in 90 of 90 samples examined, and the semiquantitative RT-PCR result showed an up-regulation of GHR mRNA expression during the polyp-adenoma-carcinoma sequence, which was consistent with the immunohistochemical results. CONCLUSIONS: Our results suggest that growth hormone/GHR plays a role in the development of colorectal carcinoma.

Proteomic analysis of colonic myofibroblasts and effect on colon cancer cell proliferation.

BACKGROUND: The stromal microenvironment influences many steps of tumor progression through the elaboration of signals from myofibroblasts. The phosphatidylinositol 3-kinase (PI3K)/Akt pathway transduces signals initiated by growth factors and is involved in colonic epithelial proliferation. The purpose of this study was to determine (1) the influence of myofibroblasts on colon cancer cell proliferation and PI3K activity, and (2) the protein alterations associated with myofibroblasts derived from polyp versus normal margins. METHODS: Myofibroblasts were derived from polyps and corresponding normal mucosa. Myofibroblasts were cocultured with colon cancer cells HT29 stably transfected with green fluorescent protein and KM20 cells. Proliferation was quantitated by green fluorescent protein count and cytokeratin enzyme-linked immunosorbent assay. HT29 cells were incubated with conditioned medium from myofibroblasts, and the effect on proliferation and PI3K activity was determined by 5-bromo 2-deoxyuridine incorporation and Akt kinase assay, respectively. Protein profiles were obtained by SELDI-TOF MS analysis. RESULTS: In coculture experiments, all myofibroblasts significantly enhanced HT29 and KM20 cell proliferation. However, polyp myofibroblasts enhanced proliferation of the cancer cells to a greater extent than normal myofibroblasts. Conditioned medium from all myofibroblasts stimulated Akt kinase activity. SELDI-TOF MS profiles showed more than 40 protein peaks for each isolate. One protein was differentially expressed in polyps versus normal cells. CONCLUSIONS: Utilizing a novel proteomic approach, we identify distinct protein profiles in myofibroblasts of polyps compared with stromal cells of normal mucosa. Moreover, myofibroblasts can stimulate indirectly PI3K activity and enhance colon cancer cell proliferation. These findings suggest that targeted therapy to signaling pathways in myofibroblasts may be useful in colorectal cancer chemoprevention and possible treatment.

The pathophysiology, clinical presentation, and diagnosis of colon cancer and adenomatous polyps.

A review of the pathophysiology, clinical presentation, and diagnosis of colon cancer and colonic polyps is important and timely. This field is rapidly changing because of breakthroughs in the molecular basis of carcinogenesis and in the technology for colon cancer detection and treatment. This article reviews colon cancer and colonic polyps, with a focus on recent dramatic advances, to help the pri-mary care physician and internist appropriately refer patients for screening colonoscopy and intelligently evaluate colonoscopic findings to reduce the mortality from this cancer.

Benign gastric polyps: morphological and functional origin.

The most common types of benign gastric polyps are fundic gland polyps, hyperplastic polyps, and adenomas. The aim of this study was to determine on which morphological and functional background benign gastric polyps develop. The study includes 85 consecutive patients with gastric polyps and sex- and age-matched controls without polyps selected at random from a general population sample. The type of polyp was hyperplastic in 52 (61%), fundic gland in 18 (21%), adenoma in 10 (12%), carcinoid in 2 (2%), hamartoma in 2 (2%), and inflammatory fibroid in 1 (1%) of the cases. Routine biopsies from the gastric corpus and antrum were examined for presence of gastritis and H. pylori. Blood samples were analyzed for H. pylori antibodies, H+,K+-ATPase antibodies, gastrin, and pepsinogen I. Patients with hyperplastic polyps had increased P-gastrin concentrations and S-H+,K+-ATPase antibody titers and decreased S-pepsinogen I concentrations with a high prevalence of atrophic corpus gastritis or pangastritis. A similar pattern was observed among patients with adenomas, whereas patients with fundic gland polyps had normal serology and a lower prevalence of gastritis and H. pylori infection than controls. In conclusion, hyperplastic polyps and adenomas are generally associated with atrophic gastritis. Patients with fundic gland polyps seem to have a sounder mucosa than controls. Whereas the risk of malignant gastric neoplasia is increased in patients with hyperplastic polyps or adenomas, this does not seem to be the case in patients with fundic gland polyps.

El abordaje retrorrectal en el tratamiento de las lesiones polipoideas sésiles del tercio medio y superior de recto / Retrorectal approach of sessile polypoid lesions of middle and proximal rectum

Antecedentes: Las lesiones polipoideas sésiles del tercio medio y superior del recto, cuando reúnen ciertas características, pueden ser extirpados utilizando un abordaje retrorrectal, del cual se han descripto múltiples variantes a la técnica original. Objetivos: Evaluar los resultados obtenidos con el uso de la modificación a la técnica de Bevan que utiliza la vía retrorrectal sin resección del coxis, ni sección del aparato esfinteriano, y remarcar los criterios de selección. Diseño: Trabajo retrospectivo. Población: Pacientes portadores de formaciones polipoideas sésiles del tercio medio y superior del recto, de ambos sexos, que presentaban los criterios de selección para la realización de esta técnica. Método: Se realizó la técnica de abordaje retrorrectal en el tratamiento de lesiones polipoideas según la técnica de Bevan modificada. Conclusiones: El abordaje retrorrectal para la resección quirúrgica de lesiones polipoedeas del recto medio y superior según esta técnica, es la vía de elección cuando dichas lesiones cumplen los criterios de selección. Su morbilidad es baja y no registramos mortalidad.

Vitamin C status and colonic neoplasia.

PURPOSE: A subnormal status of vitamin C has been associated with an increased risk for several malignant diseases and may play a causative role in their development. The aim of the present study was to investigate whether this occurs also in neoplasms of the colon. METHODS: We have studied dietary intake and status of vitamin C in a consecutive group of patients with adenomatous colonic polyps (n = 31) and compared it with that of patients with no such history and a normal colonic mucosa, as confirmed by colonoscopy (n = 54). RESULTS: Dietary intake of this vitamin, as assessed by the dietary recall method, was similar in the two groups, as were the levels of vitamin C in plasma and leukocytes. There were no significant differences in intake of dietary fiber, fat, vitamin A, or calcium between the two groups. Lack of association between vitamin C intake or status and colonic polyps persisted after adjustment for potential confounders. CONCLUSION: We conclude that in this population, a deficient status of vitamin C is not an important factor in colonic neoplasia.

Adenomas colónicos: factores de riesgo para su malignización / Colonic adenomas: risk factors for its malignization

Antecedentes: La mayoría de los cánceres colorrectales se desarrollan en pólipos adenomatosos; su detección y extirpación previene el cáncer colorrectal. Varias características de los adenomas, como: número, tamaño, morfología, variedad histológica y grado de displasia, se han considerado como factores de riesgo para su malignización. Objetivo: Conocer la frecuencia de los adenomas colorrectales los principales factores de riesgo para su malignización. Métodos: Se analizaron retrospectivamente los hallazgos endoscópicos de 846 colonoscopias realizadas en nuestro servicio entre 1989 y 1994, regisrándose los pacientes con pólipos colorrectales, así como las características de los adenomas, para determinar los factores de riesgo para su malignización. Resultados: Se encontraron 183 821.6 por ciento) pacientes con 322 pólipos colorrectales; sólo se estudiaron 214 extirpados por polipectomía transcolonoscópica; 120 (57 por ciento) fueron pólipos neoplásicos, y 94 (43 por ciento) no neoplasicos; entre los neoplásicos, 100 (83.4 por ciento) fueron adenomas tubulares, 11 (9.1 por ciento) adenomas tubulovellosos y 9 (7.5 por ciento) adenomas vellosos. Se encontraron. 16 (7.4 por ciento) adenomas con carcinoma, 14 (87.5 por ciento) de ellos en pacientes mayores de 50 años y en pólipos mayores de 1 cm (p 0.040); 11 (68.7 por ciento) fueron sésiles, con una p 0.001. Conclusiones: Los adenomas tubulares son los pólipos neoplásicos más frecuentes. La edad del paciente, el tamaño y morfología del pólipo, son los factores de riesgo significativamente estadístico para la malignización de los adenomas.

Frecuencia de pólipos en pacientes con síntomas sugestivos de transtornos funcionales colónicos estudiados con endoscopia / Frequency of colonic polyps in patients with suggestive symptoms of functional disorders evaluated by endoscopy

En nuestro país se tiene la idea de que los pólipos colónicos son una patología rara. Nos ha llamado la atención que en una población seleccionada encontramos un número significativo de pólipos en pacientes sometidos a colonoscopia por síntomas sugestivos de transtornos funcionales colónicos. En base a este hallazgo, realizamos un estudio prospectivo que incluyó a 100 pacientes de ambos sexos que fueron divididos por grupos de edades, excluyéndose aquéllos con síntomas o signos de patología colónica orgánica. En el 23 por ciento de los pacientes se encontraron pólipos adenomatosos con una frecuencia mayor a partir de los 50 años. La tolerancia al procedimiento fue buena sin complicaciones atribuibles al estudio o a la polipectomía. Concluimos que la existencia de pólipos adenomatosos colónicos es frecuente en por lo menos un sector de la población de México, y tiene gran importancia si se considera que se trata de lesiones precancerosas