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2.
Am J Gastroenterol ; 110(7): 956-62, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25803401

RESUMEN

OBJECTIVES: The Accreditation Council for Graduate Medical Education (ACGME) emphasizes the importance of medical trainees meeting specific performance benchmarks and demonstrating readiness for unsupervised practice. The aim of this study was to examine the readiness of Gastroenterology (GI) fellowship programs for competency-based evaluation in endoscopic procedural training. METHODS: ACGME-accredited GI program directors (PDs) and GI trainees nationwide completed an online survey of domains relevant to endoscopy training and competency assessment. Participants were queried about current methods and perceived quality of endoscopy training and assessment of competence. Participants were also queried about factors deemed important in endoscopy competence assessment. Five-point Likert items were analyzed as continuous variables by an independent t-test and χ(2)-test was used for comparison of proportions. RESULTS: Survey response rate was 64% (94/148) for PDs and 47% (546/1,167) for trainees. Twenty-three percent of surveyed PDs reported that they do not have a formal endoscopy curriculum. PDs placed less importance (1­very important to 5­very unimportant) on endoscopy volume (1.57 vs. 1.18, P<0.001), adenoma detection rate (2.00 vs. 1.53, P<0.001), and withdrawal times (1.96 vs. 1.68, P=0.009) in determining endoscopy competence compared with trainees. A majority of PDs report that competence is assessed by procedure volume (85%) and teaching attending evaluations (96%). Only a minority of programs use skills assessment tools (30%) or specific quality metrics (28%). Specific competencies are mostly assessed by individual teaching attending feedback as opposed to official documentation or feedback from a PD. PDs rate the overall quality of their endoscopy training and assessment of competence as better than overall ratings by trainees. CONCLUSIONS: Although the majority of PDs and trainees nationwide believe that measuring specific metrics is important in determining endoscopy competence, most programs still rely on procedure volume and subjective attending evaluations to determine overall competence. As medical training transitions from an apprenticeship model to competency-based education, there is a need for improved endoscopy curricula which are better suited to demonstrate readiness for unsupervised practice.


Asunto(s)
Competencia Clínica , Educación Basada en Competencias , Curriculum , Educación de Postgrado en Medicina , Endoscopía del Sistema Digestivo/educación , Becas , Gastroenterología/educación , Acreditación , Adulto , Benchmarking , Educación Basada en Competencias/métodos , Educación Basada en Competencias/normas , Educación Basada en Competencias/tendencias , Recolección de Datos , Educación de Postgrado en Medicina/métodos , Educación de Postgrado en Medicina/normas , Educación de Postgrado en Medicina/tendencias , Femenino , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Programas y Proyectos de Salud , Estados Unidos
3.
Dig Dis Sci ; 60(3): 748-61, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25698379

RESUMEN

Colorectal cancer (CRC) incidence and mortality are steadily declining and CRC screening rates are increasing in the United States. Although this a very good news, several definable groups still have very low screening rates including younger (under age 50) members of high-risk CRC families. This opinion piece describes five strategies that could be incorporated into routine practice to improve identification and guideline-based screening in members of high-risk families. Routine incorporation of a simple family history screening tool and outreach to high-risk family members could substantially improve guideline-based screening in this population. Identification of CRCs and advanced adenomas in the endoscopy suite defines another group of high-risk families for similar outreach. Lynch syndrome families can be identified by testing CRCs and selected adenomas for microsatellite instability or loss of DNA repair protein expression. Finally, selective addition of aspirin to surveillance endoscopy can decrease the risk of new adenomas and CRCs. The rationale for these strategies as well as mechanisms for their implementation and evaluation in clinical practice is described.


Asunto(s)
Adenoma/diagnóstico , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/prevención & control , Diagnóstico Precoz , Humanos , Tamizaje Masivo , Guías de Práctica Clínica como Asunto , Prevención Primaria
4.
Aliment Pharmacol Ther ; 41(6): 573-80, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25604623

RESUMEN

BACKGROUND: Familial occurrence is common in colorectal cancer (CRC), but whether this increased familial risk differs by colonic subsite of the index patients CRC is not well understood. AIM: To quantify the risk of CRC in first-degree (FDR), second-degree (SDR) and first cousin (FC) relatives of individuals with CRC, stratified by subsite in the colorectum and age at diagnosis. METHODS: Colorectal cancers diagnosed between 1980 and 2010 were identified from the Utah Cancer Registry and linked to pedigrees from the Utah Population Database. Age and gender-matched CRC-free controls were selected to form the comparison group for determining CRC risk in relatives using Cox regression analysis. RESULTS: Of the 18,208 index patients diagnosed with CRC, 6584 (36.2%) were located in the proximal colon, 5986 (32.9%) in the distal colon and 5638 (31%) in the rectum. The elevated risk of CRC in relatives was similar in analysis stratified for CRC colorectal subsites in the index cases. FDR had similarly elevated risk of all site CRC, whether the index patient had cancer in the proximal colon [hazards ratio (HR): 1.85; 95% CI: 1.70-2.02], distal colon (HR: 1.90; 95% CI: 1.73-2.08) or rectum (HR: 1.83; 95% CI: 1.66-2.02) compared to relatives of controls. This risk was consistently greater for FDR when cases developed CRC below the age of 60 years. CONCLUSIONS: Relatives of CRC patients have a similarly elevated risk of CRC regardless of colonic tumour subsite in the index patient, and it is greatest for relatives of younger age index cases.


Asunto(s)
Neoplasias del Colon/epidemiología , Neoplasias Colorrectales/epidemiología , Salud de la Familia , Recto/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Neoplasias del Colon/patología , Neoplasias Colorrectales/patología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Utah/epidemiología , Adulto Joven
5.
Br J Cancer ; 105(1): 162-9, 2011 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-21559014

RESUMEN

BACKGROUND: Carriers of germline mutations in DNA mismatch repair (MMR) genes have a high risk of colorectal cancer (CRC), but the modifiers of this risk are not well established. We estimated an association between body mass index (BMI) in early adulthood and subsequent risk of CRC for carriers and, as a comparison, estimated the association for non-carriers. METHODS: A weighted Cox regression was used to analyse height and weight at 20 years reported by 1324 carriers of MMR gene mutations (500 MLH1, 648 MSH2, 117 MSH6 and 59 PMS2) and 1219 non-carriers from the Colon Cancer Family Registry. RESULTS: During 122,304 person-years of observation, we observed diagnoses of CRC for 659 carriers (50%) and 36 non-carriers (3%). For carriers, the risk of CRC increased by 30% for each 5 kg m(-2) increment in BMI in early adulthood (hazard ratio, HR: 1.30; 95% confidence interval, CI: 1.08-1.58; P=0.01), and increased by 64% for non-carriers (HR: 1.64; 95% CI: 1.02-2.64; P=0.04) after adjusting for sex, country, cigarette smoking and alcohol drinking (and the MMR gene that was mutated in carriers). The difference in HRs for carriers and non-carriers was not statistically significant (P=0.50). For MLH1 and PMS2 (MutLα heterodimer) mutation carriers combined, the corresponding increase was 36% (HR: 1.36; 95% CI: 1.05-1.76; P=0.02). For MSH2 and MSH6 (MutSα heterodimer) mutation carriers combined, the HR was 1.26 (95% CI: 0.96-1.65; P=0.09). There was no significant difference between the HRs for MutLα and MutSα heterodimer carriers (P=0.56). CONCLUSION: Body mass index in early adulthood is positively associated with risk of CRC for MMR gene mutation carriers and non-carriers.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Adenosina Trifosfatasas/genética , Índice de Masa Corporal , Neoplasias Colorrectales/genética , Enzimas Reparadoras del ADN/genética , Proteínas de Unión al ADN/genética , Mutación de Línea Germinal/genética , Proteína 2 Homóloga a MutS/genética , Proteínas Nucleares/genética , Adulto , Reparación de la Incompatibilidad de ADN , Femenino , Estudios de Seguimiento , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Endonucleasa PMS2 de Reparación del Emparejamiento Incorrecto , Homólogo 1 de la Proteína MutL , Pronóstico , Factores de Riesgo , Adulto Joven
6.
Aliment Pharmacol Ther ; 22(2): 123-8, 2005 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-16011670

RESUMEN

BACKGROUND: Prior studies suggest that histamines may modulate the development of colorectal neoplasia. AIM: To assess whether histamine receptor antagonist use was associated with adenoma formation. METHODS: Patients (n = 2366) were drawn from three adenoma chemoprevention trials. All underwent baseline colonoscopy with removal of adenoma(s) and were deemed free of remaining lesions; they were followed with surveillance colonoscopy. Medication use was assessed by questionnaire. Adjusted risk ratios for adenoma formation related to histamine receptor antagonist use (histamine H1 and H2 receptor, H1RA and H2RA) were determined using log linear models. RESULTS: In pooled analyses, H1RA exposure was not associated with subsequent adenoma risk (RR = 1.10; 95% CI 0.97-1.25) or multiple adenoma formation (RR = 0.85; 95% CI 0.67-1.07). H2RA use also was not associated with adenoma (RR = 0.90; 95% CI 0.77-1.06), or multiple adenoma (RR = 0.77; 95% CI 0.57-1.04) in the pooled analyses, but H2RA users in the first trial had a decreased risk of adenoma (RR = 0.70; 95% CI 0.48-1.03) and multiple adenoma (RR = 0.31; 95% CI 0.12-0.79). CONCLUSION: H2RA use was associated with reduced risk for adenoma in one trial, but not in the pooled analyses. Further study would be warranted before undertaking randomized trials of H2RAs for adenoma chemoprevention.


Asunto(s)
Adenoma/tratamiento farmacológico , Neoplasias Colorrectales/tratamiento farmacológico , Antagonistas de los Receptores Histamínicos H1/uso terapéutico , Antagonistas de los Receptores H2 de la Histamina/uso terapéutico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto , Factores de Riesgo , Resultado del Tratamiento
7.
JAMA ; 286(16): 1985-93, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11667935

RESUMEN

CONTEXT: Since publication in 1994 of guidelines for management of peptic ulcer disease (PUD), trends in physician practice and outcomes related to guideline application have not been evaluated. OBJECTIVES: To describe changes in process of care that occurred in a quality improvement program for patients hospitalized with PUD and to evaluate associations between in-hospital treatment of PUD and 1-year rehospitalization for PUD and mortality in a subset of these patients. DESIGN, SETTING, AND PATIENTS: Cohort study of 4292 sequential Medicare beneficiaries hospitalized at acute care hospitals with a principal diagnosis of PUD in 5 states (Colorado, Georgia, Connecticut, Oklahoma, and Virginia) in 1995 (baseline) and 1997 (remeasurement); outcomes were evaluated for 752 patients in Colorado. MAIN OUTCOME MEASURES: Changes in rates of screening for Helicobacter pylori infection, treatment for H pylori infection, screening for nonsteroidal anti-inflammatory drug (NSAID) use, counseling about NSAID use; outcomes included rehospitalization for PUD and all-cause mortality within 1 year of discharge in Colorado. RESULTS: Screening for H pylori infection increased significantly (12%-19% increase; P<.001) in each of the 5 states. Treatment of H pylori infection increased in each state and was significantly increased for the entire group of hospitalizations examined (8% increase overall; P =.001). Despite increased screening, detection of H pylori infection was less frequent than expected in every state, (13%-24%) and did not increase in any state. Screening for and counseling about NSAIDs did not significantly increase overall or in any state. In the Colorado cohort, the proportion of patients rehospitalized was unchanged in 1995 (8.9%) and 1997 (6.8%), and 124 patients (16%) in the combined 1995 and 1997 cohorts died within 1 year. Treatment for H pylori was not associated with a reduction in rehospitalization within 1 year (adjusted odds ratio [OR], 1.24; 95% confidence interval [CI], 0.65-2.36) or with a reduction in mortality (adjusted OR, 1.08; 95% CI, 0.68-1.71). Counseling about NSAID use was associated with a decrease in risk of 1-year rehospitalization for PUD (adjusted OR, 0.47; 95% CI, 0.22-0.99) and risk of all-cause mortality (adjusted OR, 0.44; 95% CI, 0.26-0.75). CONCLUSIONS: This quality improvement program for elderly patients with PUD resulted in increased screening for H pylori and increased treatment of H pylori infection but no change in counseling about NSAID use. However, with the low prevalence of H pylori detected, treatment of H pylori infection was not associated with a reduction in repeat hospitalization for PUD or subsequent mortality, whereas counseling about the risks of using NSAIDs was associated with a reduction in the risk of both outcomes.


Asunto(s)
Adhesión a Directriz , Hospitales/normas , Evaluación de Procesos y Resultados en Atención de Salud , Úlcera Péptica/terapia , Anciano , Antiinflamatorios no Esteroideos/efectos adversos , Antiinflamatorios no Esteroideos/uso terapéutico , Femenino , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Mortalidad Hospitalaria , Hospitales/estadística & datos numéricos , Humanos , Modelos Logísticos , Masculino , Medicare/normas , Persona de Mediana Edad , Readmisión del Paciente , Úlcera Péptica/etiología , Guías de Práctica Clínica como Asunto , Indicadores de Calidad de la Atención de Salud , Estados Unidos/epidemiología
8.
Gastroenterology ; 121(2): 302-9, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11487539

RESUMEN

BACKGROUND & AIMS: [corrected] The goal of this study was to examine the relationship between Ki-ras mutations in colorectal adenomas and characteristics of both the subject (age, gender, and family/personal history of colonic neoplasia) and the adenoma (multiplicity, size, location, and histologic features). METHODS: Ki-ras mutations were detected by direct sequencing in 738 adenomatous polyps removed at baseline from 639 participants in a nutritional trial of adenoma recurrence. RESULTS: Ki-ras mutations were detected in 17.2% of the adenomas. Ki-ras mutations were unrelated to gender, family, or personal history of colonic neoplasia, location within the colorectum, or adenoma multiplicity, but were more common in older subjects (P = 0.01 for trend), in larger adenomas (P < 0.0001 for trend), in adenomas with villous histology (odds ratio [OR], 3.2; 95% confidence interval [CI], 2.1-4.9 vs. tubular), and in adenomas with high-grade dysplasia (32.0% vs. 13.6%; OR, 3.0; 95% CI, 1.9-4.6 vs. low-grade dysplasia). Multivariate analysis showed Ki-ras mutations to be independently associated with subject age (P = 0.01 for trend), tubulovillous/villous histology (OR, 2.3; 95% CI, 1.5-3.7), and high-grade dysplasia (OR, 1.9; 95% CI, 1.2-3.1). Adenoma size was not independently related to Ki-ras mutation. CONCLUSIONS: Ki-ras mutations are associated with the histologic features of adenoma progression (villous histology and high-grade dysplasia) rather than with adenoma growth.


Asunto(s)
Adenoma/genética , Adenoma/patología , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Genes ras/genética , Anciano , Neoplasias Colorrectales/epidemiología , Análisis Mutacional de ADN , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Mutación , Recurrencia Local de Neoplasia , Prevalencia , Proto-Oncogenes Mas
9.
JAMA ; 285(18): 2331-8, 2001 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-11343480

RESUMEN

CONTEXT: Severe gastroesophageal reflux disease (GERD) is a lifelong problem that can be complicated by peptic esophageal stricture and adenocarcinoma of the esophagus. OBJECTIVE: To determine the long-term outcome of medical and surgical therapies for GERD. DESIGN AND SETTING: Follow-up study conducted from October 1997 through October 1999 of a prospective randomized trial of medical and surgical antireflux treatments in patients with complicated GERD. Mean (median) duration of follow-up was 10.6 years (7.3 years) for medical patients and 9.1 years (6.3 years) for surgical patients. PARTICIPANTS: Two hundred thirty-nine (97%) of the original 247 study patients were found (79 were confirmed dead). Among the 160 survivors (157 men and 3 women; mean [SD] age, 67 [12] years), 129 (91 in the medical treatment group and 38 in the surgical treatment group) participated in the follow-up. MAIN OUTCOME MEASURES: Use of antireflux medication, Gastroesophageal Reflux Disease Activity Index (GRACI) scores, grade of esophagitis, frequency of treatment of esophageal stricture, frequency of subsequent antireflux operations, 36-item Short Form health survey (SF-36) scores, satisfaction with antireflux therapy, survival, and incidence of esophageal adenocarcinoma, compared between the medical antireflux therapy group and the fundoplication surgery group. Information on cause of death was obtained from autopsy results, hospital records, and death certificates. RESULTS: Eighty-three (92%) of 90 medical patients and 23 (62%) of 37 surgical patients reported that they used antireflux medications regularly (P<.001). During a 1-week period after discontinuation of medication, mean (SD) GRACI symptom scores were significantly lower in the surgical treatment group (82.6 [17.5] vs 96.7 [21.4] in the medical treatment group; P =.003). However, no significant differences between the groups were found in grade of esophagitis, frequency of treatment of esophageal stricture and subsequent antireflux operations, SF-36 standardized physical and mental component scale scores, and overall satisfaction with antireflux therapy. Survival during a period of 140 months was decreased significantly in the surgical vs the medical treatment group (relative risk of death in the medical group, 1.57; 95% confidence interval, 1.01-2.46; P =.047), largely because of excess deaths from heart disease. Patients with Barrett esophagus at baseline developed esophageal adenocarcinomas at an annual rate of 0.4%, whereas these cancers developed in patients without Barrett esophagus at an annual rate of only 0.07%. There was no significant difference between groups in incidence of esophageal cancer. CONCLUSION: This study suggests that antireflux surgery should not be advised with the expectation that patients with GERD will no longer need to take antisecretory medications or that the procedure will prevent esophageal cancer among those with GERD and Barrett esophagus.


Asunto(s)
Neoplasias Esofágicas/etiología , Estenosis Esofágica/etiología , Esofagitis/etiología , Reflujo Gastroesofágico/complicaciones , Reflujo Gastroesofágico/terapia , Adenocarcinoma/epidemiología , Adenocarcinoma/etiología , Esófago de Barrett/complicaciones , Causas de Muerte , Neoplasias Esofágicas/epidemiología , Estenosis Esofágica/epidemiología , Esofagitis/epidemiología , Esofagoscopía , Femenino , Estudios de Seguimiento , Fundoplicación , Reflujo Gastroesofágico/cirugía , Fármacos Gastrointestinales/uso terapéutico , Humanos , Concentración de Iones de Hidrógeno , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Ensayos Clínicos Controlados Aleatorios como Asunto , Índice de Severidad de la Enfermedad , Análisis de Supervivencia
10.
Cancer Res ; 61(4): 1541-7, 2001 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-11245463

RESUMEN

Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and sulindac is associated with a decreased mortality from colorectal cancer. Sulindac causes regression of precancerous adenomatous polyps and inhibits the growth of cultured colon cell lines. Whereas induction of apoptotic cell death is thought to account for the growth inhibitory effect of sulindac, less is known about its biochemical mechanism(s) of action. Sulindac is metabolized in vivo to sulfide and sulfone derivatives. Both the sulfide and sulfone metabolites of sulindac as well as more potent cyclic GMP-dependent phosphodiesterase inhibitors were shown to cause inhibition of extracellular signal-regulated kinase (ERK)1/2 phosphorylation at doses (40-600 microM) and times (1-5 days) consistent with the induction of apoptosis by the drugs. Treatment of HCT116 human colon cancer cells with the specific mitogen-activated protein kinase kinase, U0126 (5-50 microM) resulted in a time- and dose-dependent inhibition of ERK1/2 phosphorylation, and induction of apoptosis. U0126 treatment (20 microM) increased basal apoptosis, and potentiated the apoptotic effect of sulindac sulfide and sulindac sulfone. These results suggest that the inhibition of ERK1/2 phosphorylation is responsible for at least part of the induction of programmed cell death by sulindac metabolites. Inhibition of ERK1/2 activity may, therefore, be a useful biochemical target for the development of chemopreventive and chemotherapeutic drugs for human colon cancer.


Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Quinasa 1 de Quinasa de Quinasa MAP , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Sulindac/farmacología , 3',5'-GMP Cíclico Fosfodiesterasas/antagonistas & inhibidores , 3',5'-GMP Cíclico Fosfodiesterasas/metabolismo , Antiinflamatorios no Esteroideos/metabolismo , Apoptosis/fisiología , Butadienos/farmacología , Caspasa 3 , Caspasa 7 , Caspasas/metabolismo , Neoplasias del Colon/enzimología , Neoplasias del Colon/patología , Regulación hacia Abajo , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/fisiología , Proteína Quinasa 1 Activada por Mitógenos/antagonistas & inhibidores , Proteína Quinasa 1 Activada por Mitógenos/biosíntesis , Proteína Quinasa 3 Activada por Mitógenos , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas Activadas por Mitógenos/biosíntesis , Nitrilos/farmacología , Fosforilación/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/metabolismo , Sulindac/análogos & derivados , Sulindac/metabolismo , Células Tumorales Cultivadas/efectos de los fármacos
12.
Carcinogenesis ; 21(11): 1935-40, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11062151

RESUMEN

Mutations of the APC gene are thought to be early events in the process of colorectal carcinogenesis. Although the complete function(s) of the APC gene product is not known, it has been shown that the APC protein interacts with beta-catenin in a multi-protein complex to regulate the level of expression of beta-catenin. Loss of normal APC protein function can lead to an accumulation of beta-catenin in the cytosol and the nucleus. Immunohistochemical methods were used to determine the relationship between APC and beta-catenin protein expression in human colonic tissues (150 normal, 9 hyperplastic, 58 adenomas and 83 carcinomas) and 12 paired samples of normal and cancer tissue in mouse colon. In all samples of normal human and mouse colonic mucosa and in human hyperplastic polyps both APC and beta-catenin immunoreactivity were present in colonocytes. APC expression was cytoplasmic, with maximal immunoreactivity in the goblet cells. beta-Catenin expression was predominantly localized to the plasma membrane, with no nuclear immunoreactivity. APC immunoreactivity was absent in all of the mouse adenocarcinomas and 83% of the human colon cancers. All of the human and mouse carcinomas had nuclear and cytoplasmic beta-catenin expression. In contrast, only 29% of the 58 colonic adenomas were completely negative for APC immunoreactivity. Regardless of the presence or absence of APC, all of the adenomas had cytoplasmic and nuclear beta-catenin immunoreactivity. Many colonic adenomas retain expression of full-length APC protein whereas it is usually lost in colorectal cancers. Regardless of the status of APC protein expression, beta-catenin protein was found in the cytoplasm and nucleus of all neoplastic colonic mucosa. The dissociation between loss of expression of APC and accumulation of beta-catenin in the nucleus suggests that inactivation of both alleles of the APC gene may not be required for beta-catenin nuclear accumulation in colonic adenomas.


Asunto(s)
Colon/metabolismo , Neoplasias del Colon/metabolismo , Proteínas del Citoesqueleto/biosíntesis , Transactivadores , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Adenoma/metabolismo , Adenoma/patología , Proteína de la Poliposis Adenomatosa del Colon , Animales , Colon/patología , Neoplasias del Colon/patología , Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/inmunología , Progresión de la Enfermedad , Humanos , Hiperplasia/metabolismo , Inmunohistoquímica , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Ratones , Lesiones Precancerosas/metabolismo , Lesiones Precancerosas/patología , beta Catenina
14.
N Engl J Med ; 343(3): 162-8, 2000 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-10900274

RESUMEN

BACKGROUND AND METHODS: The role of colonoscopy in screening for colorectal cancer is uncertain. At 13 Veterans Affairs Medical Centers, we performed colonoscopy to determine the prevalence and location of advanced colonic neoplasms and the risk of advanced proximal neoplasia in asymptomatic patients (age range, 50 to 75 years) with or without distal neoplasia. Advanced colonic neoplasia was defined as an adenoma that was 10 mm or more in diameter, a villous adenoma, an adenoma with high-grade dysplasia, or invasive cancer. In patients with more than one neoplastic lesion, classification was based on the most advanced lesion. RESULTS: Of 17,732 patients screened for enrollment, 3196 were enrolled; 3121 of the enrolled patients (97.7 percent) underwent complete examination of the colon. The mean age of the patients was 62.9 years, and 96.8 percent were men. Colonoscopic examination showed one or more neoplastic lesions in 37.5 percent of the patients, an adenoma with a diameter of at least 10 mm or a villous adenoma in 7.9 percent, an adenoma with high-grade dysplasia in 1.6 percent, and invasive cancer in 1.0 percent. Of the 1765 patients with no polyps in the portion of the colon that was distal to the splenic flexure, 48 (2.7 percent) had advanced proximal neoplasms. Patients with large adenomas (> or = 10 mm) or small adenomas (< 10 mm) in the distal colon were more likely to have advanced proximal neoplasia than were patients with no distal adenomas (odds ratios, 3.4 [95 percent confidence interval, 1.8 to 6.5] and 2.6 (95 percent confidence interval, 1.7 to 4.1], respectively). However, 52 percent of the 128 patients with advanced proximal neoplasia had no distal adenomas. CONCLUSIONS: Colonoscopic screening can detect advanced colonic neoplasms in asymptomatic adults. Many of these neoplasms would not be detected with sigmoidoscopy.


Asunto(s)
Adenoma/diagnóstico , Colonoscopía , Neoplasias Colorrectales/diagnóstico , Adenoma/epidemiología , Adenoma/patología , Anciano , Pólipos del Colon/patología , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/patología , Estudios de Evaluación como Asunto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Invasividad Neoplásica , Prevalencia
15.
Cancer Res ; 60(13): 3338-42, 2000 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-10910034

RESUMEN

Sulindac sulfone (exisulind), although a nonsteroidal anti-inflammatory drug derivative, induces apoptosis in tumor cells by a mechanism that does not involve cyclooxygenase inhibition. SW480 colon tumor cells contain guanosine 3',5'-monophosphate (cGMP) phosphodiesterase (PDE) isoforms of the PDE5 and PDE2 gene families that are inhibited by exisulind and new synthetic analogues. The analogues maintain rank order of potency for PDE inhibition, apoptosis induction, and growth inhibition. A novel mechanism for exisulind to induce apoptosis is studied involving sustained increases in cGMP levels and cGMP-dependent protein kinase (PKG) induction not found with selective PDE5 or most other PDE inhibitors. Accumulated beta-catenin, shown to be a substrate for PKG, is decreased by exisulind, suggesting a mechanism to explain apoptosis induction in neoplastic cells harboring adenomatous polyposis coli gene mutations.


Asunto(s)
3',5'-GMP Cíclico Fosfodiesterasas/antagonistas & inhibidores , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Proteínas del Citoesqueleto/metabolismo , Inhibidores de Fosfodiesterasa/farmacología , Proteínas Quinasas/metabolismo , Sulindac/análogos & derivados , Transactivadores , 3',5'-GMP Cíclico Fosfodiesterasas/genética , Cadherinas/metabolismo , Neoplasias del Colon , GMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de GMP Cíclico/metabolismo , Activación Enzimática , Humanos , Isoenzimas/antagonistas & inhibidores , Isoenzimas/genética , Cinética , Piperidinas/farmacología , Quinazolinas/farmacología , Sulindac/farmacología , Células Tumorales Cultivadas , beta Catenina
16.
Aliment Pharmacol Ther ; 14(6): 651-68, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10848649

RESUMEN

This review examines the evidence for the development of adverse effects due to prolonged gastric acid suppression with proton pump inhibitors. Potential areas of concern regarding long-term proton pump inhibitor use have included: carcinoid formation; development of gastric adenocarcinoma (especially in patients with Helicobacter pylori infection); bacterial overgrowth; enteric infections; and malabsorption of fat, minerals, and vitamins. Prolonged proton pump inhibitor use may lead to enterochromaffin-like cell hyperplasia, but has not been demonstrated to increase the risk of carcinoid formation. Long-term proton pump inhibitor treatment has not been documented to hasten the development or the progression of atrophic gastritis to intestinal metaplasia and gastric cancer, although long-term studies are required to allow definitive conclusions. At present, we do not recommend that patients be tested routinely for H. pylori infection when using proton pump inhibitors for prolonged periods. Gastric bacterial overgrowth does increase with acid suppression, but important clinical sequelae, such a higher rate of gastric adenocarcinoma, have not been seen. The risk of enteric infection may increase with acid suppression, although this does not seem to be a common clinical problem with prolonged proton pump inhibitor use. The absorption of fats and minerals does not appear to be significantly impaired with chronic acid suppression. However, vitamin B12 concentration may be decreased when gastric acid is markedly suppressed for prolonged periods (e.g. Zolllinger-Ellison syndrome), and vitamin B12 levels should probably be assessed in patients taking high-dose proton pump inhibitors for many years. Thus, current evidence suggests that prolonged gastric acid suppression with proton pump inhibitors rarely, if ever, produces adverse events. Nevertheless, continued follow-up of patients taking proton pump inhibitors for extended periods will provide greater experience regarding the potential gastrointestinal adverse effects of long-term acid suppression.


Asunto(s)
Adenocarcinoma/inducido químicamente , Antiulcerosos/efectos adversos , Tumor Carcinoide/inducido químicamente , Ácido Gástrico/metabolismo , Inhibidores de la Bomba de Protones , Neoplasias Gástricas/inducido químicamente , Antiulcerosos/administración & dosificación , Infecciones por Helicobacter/complicaciones , Humanos , Síndromes de Malabsorción/inducido químicamente , Factores de Riesgo , Gastropatías/inducido químicamente , Úlcera Gástrica/tratamiento farmacológico
17.
Cancer Epidemiol Biomarkers Prev ; 9(2): 229-32, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10698488

RESUMEN

End points for trials promoting cancer screening are often based on self-reported screening behavior. This study was designed to evaluate and optimize the reliability of a computer-assisted telephone interview for collecting self-reported colorectal cancer screening behavior. Cases who had received a fecal occult blood test (FOBT), flexible sigmoidoscopy, and/or colonoscopy, and controls who had no record of colorectal screening were identified among 40-75-year-old members of the Denver Kaiser Permanente Health Care Program and were contacted by telephone. Sensitivities and specificities of self-reported screening were calculated by comparison of subjects' recall with Kaiser Permanente records. The questionnaire was revised based upon results of the pilot phase of the study. Using the revised questionnaire, the sensitivity of self-reported screening was 96.2% for the FOBT, 94.9% for flexible sigmoidoscopy, 88.7% for colonoscopy, and 96.2% for either endoscopic screening test. The specificity of self-reported screening was 85.9% for the FOBT, 92.2% for flexible sigmoidoscopy, 96.8% for colonoscopy, and 92.0% for either endoscopic screening test. No marked differences in the accuracy of the self-reports were detected as a function of gender, age, ethnicity, or family history of colorectal cancer of the participants. Self-reports of colon cancer screening behavior can be reliably used as end points for intervention trials when carefully phrased questions are used.


Asunto(s)
Neoplasias Colorrectales/diagnóstico , Conductas Relacionadas con la Salud , Tamizaje Masivo , Cooperación del Paciente , Adulto , Anciano , Colonoscopía , Recolección de Datos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sangre Oculta , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Sigmoidoscopía , Teléfono , Revelación de la Verdad
18.
Cancer Res ; 59(20): 5181-5, 1999 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-10537295

RESUMEN

The Ki-ras protooncogene frequently is mutated in colorectal adenocarcinomas, but the etiology of this molecular event is uncertain. We investigated the association between variables known or suspected to be related to risk for colorectal cancer and the occurrence of Ki-ras mutations in colorectal adenomas. This study was conducted among 678 male and female participants, 40-80 years of age, enrolled in a phase III trial testing the effects of a wheat bran fiber supplement on adenoma recurrence. Exposure information on the risk factors of interest was assessed through self-administered questionnaires. Mutations in codons 12 and 13 of the Ki-ras protooncogene were analyzed in baseline adenomas 0.5 cm or larger by PCR amplification followed by direct sequencing. Eighteen percent (120 of 678) of the participants had one or more adenoma(s) with Ki-ras mutations. A higher risk of Ki-ras mutations was associated with increasing age and a lower intake of total folate. The odds ratio (OR) for Ki-ras mutations for individuals >72 years of age was 1.98 [95% confidence interval (CI) = 1.19-3.27; P for trend = 0.008] compared with those less than 65 years of age. Compared with individuals in the lower tertile of total folate, those in the upper tertile had an approximately 50% lower risk of having Ki-ras mutation-positive adenomas (OR = 0.52; 95% CI = 0.30-0.88; P for trend = 0.02). There was a suggestion of a stronger inverse association of total folate with G-->T transversions (OR = 0.41; 95% CI = 0.20-0.87) than G-->A transitions (OR = 0.61; 95% CI = 0.31-1.21), although the CIs for the associations overlap. The results of these analyses suggest that the protective effect of folate in colon cancer observed in published studies may be mediated through folate's effect on Ki-ras mutations.


Asunto(s)
Adenoma/genética , Neoplasias Colorrectales/genética , Genes ras , Mutación , Adenoma/etiología , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Colorrectales/etiología , Metilación de ADN , Femenino , Ácido Fólico/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo
19.
Prev Med ; 28(3): 229-42, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10072740

RESUMEN

BACKGROUND: In this paper two large nationwide trials are described, both of which will test a comparable telephone-based counseling intervention to promote cancer screening among the first-degree relatives (FDRs) of breast and colorectal cancer patients. The unit of randomization will be the family unit of eligible FDRs. Access to FDRs will be obtained from their relatives with cancer. Selected intervention and design issues are reviewed, including how both projects will respond to FDRs who exhibit significant levels of cancer-specific anxiety or distress and how potential high-risk cancer families will be accommodated. METHODS: Pursuant to the development of both studies, two feasibility surveys were conducted to determine whether patients would grant access to their FDRs and whether the FDRS identified by these patients would be receptive to the telephone intervention. RESULTS: Approximately 80% (106 of 132) of breast cancer patients agreed to provide access to their eligible FDRs when contacted on-site at participating hospitals and clinics. Of those subsequently selected for telephone follow-up (n = 95 or 90%), 80% (n = 76) were successfully contacted by telephone, and of these 97% (n = 74) provided the names and telephone numbers of their FDRs. Among colorectal cancer patients contacted on-site (n = 46), 96% (n = 44) agreed to provide access to their FDRs, and of those contacted by telephone (n = 33 or 75%), 91% (n = 30) provided the requested information about their FDRs. Once contacted, 95% of breast cancer FDRs (55 of 58) and 91% of colorectal cancer patients (51 of 56) endorsed the intervention strategy. CONCLUSIONS: It is argued that this intervention, if proven effective, could provide an exportable strategy for reaching large numbers of high-risk individuals to promote cancer screening.


Asunto(s)
Neoplasias de la Mama/prevención & control , Neoplasias Colorrectales/prevención & control , Consejo/métodos , Familia/psicología , Promoción de la Salud/métodos , Tamizaje Masivo/estadística & datos numéricos , Ensayos Clínicos Controlados Aleatorios como Asunto , Proyectos de Investigación , Algoritmos , Estudios de Factibilidad , Femenino , Humanos , Consentimiento Informado , Masculino , Anamnesis , Selección de Paciente , Linaje , Encuestas y Cuestionarios , Teléfono , Estados Unidos
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