View clinical trials related to Adenoma.
Filter by:This is a randomized controlled trial of aspirin and/or folate supplementation for the prevention of the recurrence of neoplastic polyps (adenomas) of the large bowel.
The proposed research aims to determine the prevalence, size, shape and histology of flat colorectal neoplasms in a cohort of asymptomatic, average-risk individuals presenting for screening colonoscopy. Patients will be randomized to either conventional colonoscopy or chromocolonoscopy, where the entire colon will be sprayed with indigocarmine dye and examined in the usual manner. The primary outcome will be the total number of adenomas detected, with special attention to the subgroup of flat and depressed lesions. To promote the generalizability of the results, neoplasms will be described according to standard Western and Japanese classification schemes.
Experimental and epidemiologic studies have suggested that aspirin intake reduces the risk for colorectal cancer. In the APACC study we randomly assigned 291 patients to daily Aspirin or Placebo for 4 years. However, the available data are not sufficient to serve as the basis for firm recommendations
Dopamine (DA) is one of the main catecholamines in mammals. Its major role as a brain neurotransmitter is well known as well as its contribution to the development of pathologies, mainly arterial hypertension. Traditionally, dopamine receptors are divided into two families according to the stimulation or inhibition they may produce at the adenyl cyclase level. Five dopamine receptors have been identified: D1 (D1a) and D5 (D1b) exist in the D1 family. D2s, D2l, D3 and D4 belong to the D2 family. Formerly, less than 1% of patients with hypertension were believed to have primary hyperaldosteronism; however, recent studies have suggested that primary aldosteronism affects 5-13% of patients with hypertension and aldosteronomas are a more common cause of hypertension than previously thought. At least 2% of patients with hypertension may have an aldosteronoma. The investigators' previous clinical observation found two subtypes of aldosterone-producing adenoma (APA), which were defined according to their responses to metoclopramide during salt manipulation. On a high-salt diet (HS), the nonsuppressible subjects, with less dopaminergic inhibition of aldosterone secretion, had less urinary DA excretion and greater blood pressure (BP) elevation [Wu KD et al. 2002]. The investigators' recent study of six patients with an APA found that the expression of the D2 receptor in APA was not universal. The amounts of D2 receptor messenger ribonucleic acid (mRNA) were more variant in either APA or their remnant adrenal glands. Only two cases of APA expressed the D2 receptors with much weaker signals compared with those in their respective remnant adrenals [Wu KD et al. 2001]. The investigators' current work demonstrates that the D2 receptor negatively regulates AII-stimulated aldosterone secretion and aldosterone synthase mRNA expression in NCI-H295R cells. On the other hand, the D4 receptor counteracts with the effect of the D2 receptor. In a future study, the investigators wish to quantify D2 and D4 receptor mRNA and protein expression in APA and their remnant adrenal glands and correlate them to their clinical metoclopramide test results. The investigators also wish to know whether the difference between the D2 and D4 receptor expression reflect the different effects of dopamine inhibition on AII-stimulated aldosterone secretion and aldosterone synthase transcription. Finally, the investigators will explore the role of D2 and D4 receptors on AII-stimulated adrenal cell proliferation.
Extensive experimental and observational data suggest that intake of calcium and of vitamin D exert protective effects on colorectal neoplasia. Building on their previous work, the investigators will investigate the chemopreventive effect of vitamin D in the large bowel, to study whether calcium with vitamin D is more effective than calcium alone, and to confirm their positive finding regarding calcium. The goal of this study is the development of chemopreventive combinations that will reduce risk of colorectal neoplasia sufficiently to permit the lengthening of surveillance intervals in most patients and to clarify important issues regarding the mechanisms of colorectal carcinogenesis and chemoprevention.
Malignant transformation of adenomas of the duodenum is now the leading cause of death in familial adenomatous polyposis (FAP) patients who had a restorative proctocolectomy. Ursodeoxycholic acid (UDCA) modifies the biliary acid profile and could reduce the severity of duodenal adenomas and prevent such transformation.
The purpose of this study is to see if screening with flexible sigmoidoscopy (a flexible viewing tube) may reduce large bowel cancer and cancer deaths. The researchers also want to see if the addition of screening for occult blood in stools may contribute further to this aim. Additionally, the researchers also want to see to which extent (and in which direction) the study may influence overall endoscopic activity in the general population in the screening area and in areas where controlled screening is not established.
Colorectal neoplasia is the second most common cancer in the United States and other Western countries with about 140,000 newly diagnosed cases per year in the United States with a mortality rate of about 40%. The identification of a specific natural or synthetic compound with the ability to reverse or suppress the process of colon carcinogenesis would have profound implication in the development of colorectal adenomas and their subsequent transformation to colon cancer. Furthermore, the establishment of a correlative relationship between biomarkers of cell proliferation, differentiation, apoptosis and adenoma recurrence would provide pivotal data required to elucidate cell signaling mechanisms in future colon cancer chemoprevention trials.
Lentiginosis refers to groups of diseases marked by the presence of pigmented spots on the skin. These conditions are most commonly associated with multiple tumors and changes in hormone producing glands. The cause of these diseases is unknown, but researchers suggest there may be a level of inheritance involved in their development. Meaning to say that some of these diseases may "run in the family" and be passed down form generation to generation. Primary pigmented nodular adrenocortical disease (PPNAD) is a pituitary-independent, primary adrenal form of hypercortisolism characterized by; 1. Resistance to suppression by the drug dexamethasone 2. The body is unable to secrete cortisol in a normal rhythm 3. Distinct microscopic changes of both adrenal glands PPNAD can be associated with tumors (myxomas) of the skin, heart, breast, tumors (swannomas) of the nerve sheaths, pigmented spots (nevi and lentigines) of the skin, growth hormone (GH) producing tumors of the pituitary gland, and tumors of the testicles, ovaries, and thyroid gland. In the presence of these associations the condition is referred to as the Carney Complex. Presently there are no tests for screening of PPNAD and the Carney Complex. In addition, it is unknown how these conditions are genetically transferred from generation to generation. This study proposes to use standard methods of clinical testing for endocrine and nonendocrine diseases and genetic testing in order to; 1. Define the genetic basis for PPNAD and/or the Carney Complex. 2. Determine the molecular changes associated with the development of the tumors. 3. Identify carriers of the disease. 4. Determine the prognosis for carriers and affected individuals. 5. Provide sufficient data for genetic counseling of families with PPNAD and/or Carney Complex.<TAB>...
This study will examine the safety and effectiveness of interferon-a and octreotide for the treatment of Zollinger-Ellison syndrome (gastrinoma) and advanced non-B islet cell cancer. Gastrinoma is a tumor produced by the pancreas that secretes the hormone gastrin, which in turn stimulates production of gastric juices that cause ulcers. Some of these tumors are malignant. Gastrinomas that have spread and cannot be surgically removed require drug treatment (chemotherapy). Current drug regimens, however, provide only temporary benefit and, in some cases, produce life-threatening side effects. In studies of patients with tumors similar to gastrinoma, the drugs octreotide and interferon-a, alone or in combination, showed some effect in stopping tumor growth and were better tolerated than chemotherapy. At least one-third of patients responded to treatment with either drug for at least 6 months; the two drugs given together may produce a better response than either one alone. Patients currently enrolled in an NIH study of Zollinger-Ellison syndrome whose gastrinoma has spread from the original site and cannot be surgically removed may be eligible for this study. Participants will be admitted to the NIH Clinical Center for blood and urine tests, electrocardiogram (EKG), chest X-ray and imaging studies (CT, ultrasound, MRI, octreoscan, and bone scan) before beginning treatment to evaluate the size and extent of tumors. Patients will then start interferon-a or octreotide, or both, given as injections under the skin. Treatment will continue for at least 6 months, unless side effects require stopping the drugs early. Patients whose tumors shrink or remain stable may continue treatment indefinitely. Those who do not respond to treatment will be taken off the study and offered standard chemotherapy. Patients will be admitted to the hospital for the first day or two of therapy to be monitored for side effects and to learn how to self-inject the drugs to continue therapy at home. Both drugs are given [Note: how often? once a day, twice a day, weekly?] (Octreotide is also available in long-acting form, and patients who prefer may be given this drug once a month by the doctor.) During the treatment period, patients will be seen by their personal physician every 2 weeks for the first month and once a month thereafter for a medical evaluation and check of adverse side effects of treatment. In addition, they will be admitted to the NIH Clinical Center once every 3 months for a medical evaluation and imaging studies, including CT, MRI, ultrasound, bone scan, and octreoscan, to assess the effect of treatment on tumor size.