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PubMed2003

Selective COX-2 inhibitors as chemopreventive and therapeutic agents.

Selective cyclooxygenase-2 (COX-2) inhibitors have received increasing attention for their role in the prevention and treatment of cancer. Considerable preclinical data support this use. Furthermore, clinical studies have shown that this enzyme is upregulated in a variety of premalignant and malignant states and that its inhibition can decrease colon polyp formation in patients with familial adenomatous polyposis. A number of studies are now investigating the use of COX-2 inhibitors to prevent or treat a number of different cancers. These ongoing trials will determine whether these agents are useful in the treatment of cancer.

Animals↗
PubMed2000

Gastrointestinal effects of growth hormone.

GH receptor immunoreactivity is found throughout the gastrointestinal tract. GH has proliferative effects upon intestinal epithelium, and influences enteroendocrine cell secretion, calcium absorption, and intestinal amino acid and ion transport. The proliferative effects of GH may be reflected in the increased incidence of neoplastic colonic polyps in individuals with long-term GH excess reported by some investigators. GH also increases hepatic cytochrome P450 expression, potentially altering drug and steroid hormone metabolism. Current clinical research efforts include the use of exogenous GH as a stimulant of gut growth and adaptation in patients who have undergone massive intestinal resection. Exogenous GH is also being studied in animal models of critical illness where it appears to increase intestinal glutamine uptake, which may prevent deterioration of the intestinal mucosal barrier.

Animals↗
PubMed1994

Colonoscopic polypectomy with local injection of methylene blue.

For safer and complete colonoscopic polypectomy of large broad-based adenomas, we attempted submucosal injection of methylene blue before electrosurgical snare excision. Twenty-five large broad-based sessile adenomas 20 mm or more in diameter were resected. Methylene blue was injected about 2 mm away from the edge of the lesion. After injection, the lesion appearing as a blue bleb was resected by snare polypectomy. All the lesions were completely resected by single-step polypectomy. During and after polypectomy, no complication occurred. Endoscopic resection of large sessile adenomas with the aid of submucosal injection of methylene blue thus appears to be safe and effective.

Adenomatous Polyps↗
PubMed2003

Cancer chemoprevention drug targets.

Cancer chemoprevention is a new approach in the management of cancer. Traditional cytotoxic chemotherapeutic approaches cannot cure most advanced solid malignancies. Chemoprevention can be defined as the use of non-cytotoxic drugs and natural agents to block the progression to invasive cancer. Chemoprevention can either prevent DNA damage that initiates the neoplastic transformation process or reverses the progression of pre-invasive lesions. Epidemiological observations, experimental evidence from animal carcinogenesis models, knock-out models, cancer cell lines and clinical trials have shown the efficacy of this approach. Recent advances in our understanding of carcinogenesis have led to the synthesis of new drugs that target specific receptors. Non-steroidal anti-inflammatory drugs target the prostaglandin pathway. The identification of the role of cyclooxygenase-2 in epithelial carcinogenesis led to the synthesis of selective cyclooxygenase-2 inhibitors (Celecoxib). Celecoxib was subsequently approved for the prevention of colon polyps in familial adenomatous polyposis after the completion of a randomized clinical trial. The large chemoprevention clinical trial with the selective estrogen receptor modulator, tamoxifen, showed the benefit of tamoxifen in the prevention of breast cancer in high-risk women. Retinoids and rexinoids target the retinoid receptors and have a role in chemoprevention of aerodigestive, hepatic and cervical neoplasia. Selenium, an inhibitor of the glutathione peroxidase system, is being tested in the chemoprevention of prostate cancer and lung cancer. The different isoforms of vitamin E (tocopherols) may be chemopreventive. Recent evidence indicates that gamma-tocopherol may be a more powerful chemopreventive than the alpha-tocopherol. The review details the rationale, experimental and clinical evidence and the drug targets of the chemopreventive agents that are currently in various phases of clinical development.

Animals↗
PubMed2005

Full-body cardiovascular and tumor MRI for early detection of disease: feasibility and initial experience in 298 subjects.

OBJECTIVE: High diagnostic accuracy, emerging whole-body concepts, and lack of side effects combine to render MRI a natural candidate for screening purposes. The aim of this study was to evaluate the technical feasibility of a comprehensive multiorgan-targeting MRI examination and determine the frequency of findings in subjects without a history of serious disease. SUBJECTS AND METHODS: The study group was composed of 331 subjects. The MRI protocol (mean examination time, 63 min) encompassed the target organs: the brain, arterial system, heart, and colon. Diagnoses were deemed relevant if the physician had to inform the subject about the findings. Subjects with a history of serious illnesses were excluded from subsequent analysis (n=33). All analyses were performed for the resulting subgroup of 298 subjects (247 men, 51 women; mean age, 49.7 years). RESULTS: All 298 examinations were diagnostic excluding eight MR colonography components in which remaining stool hampered reliable diagnosis. Follow-up or radiologic confirmation could be obtained in 75% of all cases with relevant findings (128/169); only one false-positive result was encountered. Of the study group, 21% exhibited signs of atherosclerotic disease. Two cerebral infarctions and one myocardial infarction, previously unknown, were encountered; 12% had peripheral vascular disease. Twelve colonic polyps and nine pulmonary lesions were correctly detected. Of all MRI examinations, 29% revealed relevant additional findings in nontargeted organs. Only one minor allergoid reaction was encountered. CONCLUSION: The presented data point toward an increased use of MRI for screening in the future, but to date screening MRI should not be performed outside a research setting because the cost-benefit relation is unclear.

Adult↗
PubMed1991

Long-time survival of a patient with glioblastoma and Turcot's syndrome. Case report.

A rare case of Turcot's syndrome is reported in a long-time survivor of glioblastoma multiforme. The patient was treated for his tumor in 1976 with macroscopically complete surgical resection and radiotherapy consisting of 60 Gy to the tumor bed and 40 Gy to the whole brain. Five years later, in 1981, he developed adenocarcinoma of the colon Dukes Stage B which was successfully treated at another hospital by surgery alone. In 1990, he presented with multiple colon polyps and adenocarcinoma Dukes Stage A. For more than 15 years, the patient has been afflicted with cystic and conglobate acne. Possible mechanisms and treatment with 13-cis retinoic acid are discussed.

Acne Vulgaris↗
PubMed2006

Colorectal screening after polypectomy: a national survey study of primary care physicians.

BACKGROUND: Recommendations by primary care physicians for colorectal screening after polypectomy will influence rates of colonoscopy in open-access systems that do not require consultation by a gastroenterologist before colonoscopy. OBJECTIVE: To determine the surveillance recommendations of primary care physicians after polypectomy and compare them with recommendations from the U.S. Multisociety Task Force on Colorectal Cancer. DESIGN: Cross-sectional study of physicians. SETTING: United States. PARTICIPANTS: A random sample of 500 physicians from the American College of Physicians and 500 physicians from the American Academy of Family Physicians, obtained by using a mail survey. MEASUREMENTS: Physicians were asked when they would recommend repeated colonoscopy for a hypothetical 55-year-old man with no family history of colorectal cancer after the following 6 results on colonoscopy: hyperplastic polyp, one 6-mm tubular adenoma, two 6-mm tubular adenomas, one 12-mm tubulovillous adenoma, one 12-mm tubular adenoma with focal high-grade dysplasia, and no polyp but a previous tubular adenoma. RESULTS: The overall response rate was 57% (568 physicians). Of the respondents, 48% were internists and 52% were family practitioners. Sixty-one percent of respondents would survey a hyperplastic polyp in 5 years or less, 71% would survey a single tubular adenoma in 3 years or less, and 80% would survey 2 tubular adenomas in 3 years or less. LIMITATIONS: The results are based on physicians' self-reported practices from clinical vignettes and may not match actual practice. CONCLUSION: Primary care physicians recommend postpolypectomy colonoscopic surveillance more frequently than is recommended by practice guidelines, especially if the colonoscopy showed a hyperplastic polyp or a single small adenoma.

Adenoma, Villous↗
PubMed1999

Enhanced epithelial cell turnover associated with p53 accumulation and high p21WAF1/CIP1 expression in ulcerative colitis.

To cast light on accelerated epithelial cell turnover as an important risk factor of dysplasia and carcinoma development in patients with long-standing ulcerative colitis (UC), we examined cell proliferation and cell death, as well as expression of apoptosis-related markers, including p53 and p21WAF1/CIP1, in a series of cases. Biopsy specimens (n = 176; 84, active phase; 92, remission) were endoscopically obtained from 25 Japanese patients with UC. As controls, 68 biopsy specimens of normal mucosa were also examined from 27 Japanese patients with colon polyps. We counted the numbers of mitoses, apoptotic bodies, Ki-67-immunoreactive cells, and p21WAF1/CIP1-immunoreactive cells per 1000 crypt cells and the numbers of p53-positive cells per crypt. All of the indices in active UC were significantly higher than in either remitting UC cases or normal cases (mean mitotic index = 0.52, 0.28, and 0.15%, respectively; apoptotic index = 5.40, 2.91, and 1.30%, respectively; Ki-67 labeling index = 39.5, 28.3, and 26.8%, respectively; p21WAF1/CIP1 labeling index = 33.6, 20.0, and 19.0%, respectively; p53 labeling index = 0.66, 0.13, 0.13 per crypt, respectively). In addition, the mitotic, apoptotic, and Ki-67 labeling indices were increased in remitting UC of more than 10 years' duration, in comparison with those of less than 10 years' duration or the normal group. Immunostaining of serial sections revealed a small number of crypt cells coexpressing p53 and p21WAF1/CIP1. Increases in both epithelial cell proliferation and cell death, partially associated with p53 accumulation and high p21WAF1/CIP1 expression, are thus characteristic of active phase UC, as well as in remission of long-standing UC. Accelerated epithelial cell turnover caused by chronic inflammation and epithelial damage might predispose the mucosa to DNA damage, resulting in an elevated risk of mutation in line with dysplasia and carcinoma development in patients with UC.

Adult↗
PubMed1999

The somatopause is no indication for growth hormone therapy.

Growth hormone (GH) secretion in the elderly is generally diminished although there are marked individual differences ranging from normal GH secretion and normal levels of insulin-like growth factor (IGF)-I through low GH and subnormal IGF-I. It is assumed that the reduced central cholinergic activity leading to unrestrained somatostatin release leads to impaired GH secretion. The somatopause, if it occurs at all, is, in contrast to the menopause, a subtly developing physiological event. The menopause often causes severe symptoms that justify hormone replacement therapy, but the somatopause is a physiological event at the end of the lifespan with no acute symptoms that can be attributed to GH deficiency with certainty. Whether the non-specific symptoms of old age, i.e. truncal obesity, muscle atrophy, decreasing energy, and mental disorders, can be--even partially--blamed on decreased GH secretion is unclear. Thus, GH therapy in elderly patients, in the absence of pituitary disease cannot be recommended. In addition, the following has to be considered: 1) GH has to be given by subcutaneous injection, which may be technically difficult in elderly patients. 2) It is difficult to find the right individual dosage of GH since elderly patients may show increased sensitivity to GH therapy (compared with children) or may be GH-resistant. 3) Manifestation of diabetes mellitus may be enhanced in elderly patients. 4) The elevation of IGF-I levels may enhance the progression of malignant disease; it has been shown that the concentration of IGF-I in the circulation correlates to the frequency of prostatic cancer. Furthermore, acromegalic patients have a higher frequency of colonic polyps and gastrointestinal malignancies. 5) Even if problems such as dosage, mode of application and the questions of safety are resolved, the present costs of GH therapy will not allow to advocate GH treatment of all elderly patients with low levels of IGF-I. However, since some patients seem to benefit from GH therapy in senescence, further studies are needed. There may be a subset of elderly patients in whom GH treatment is useful. However, unless these patients are included in a study protocol, GH treatment should not be given to elderly patients in the absence of pituitary disease.

Aged↗
PubMed1999

Multiple perifollicular fibromas.

Perifollicular fibroma is a benign mesodermal tumour of the hair follicle. It can occur as a solitary papule or as multiple lesions that are clinically indistinguishable from other tumours of the pilar apparatus. Multiple perifollicular fibromas may be inherited although the pattern remains unclear. Adnexal tumours can be associated with internal malignancy and perifollicular fibromas have been linked with adenomatous colonic polyps. This report describes a patient with multiple perifollicular fibromas with no associated malignancy to date and a family pedigree suggestive of an autosomal dominant pattern of inheritance.

Adult↗
PubMed1999

Pulmonary abnormalities in Cowden's disease.

Cowden's disease is an inheritable multiple neoplastic syndrome represented by benign and malignant lesions of skin, digestive tract, mucosae, breast and thyroid. The syndrome, first described by Lloyd and Dennis in 1963, includes benign lung lesions, described in the literature only as hamartomas. The unusual condition of our case consists of multiple and bilateral lipomatous lesions of the lung and of adipose colonic polyps, diagnosed respectively by video assisted mini-thoracotomy and by endoscopic biopsies.

Biopsy↗
PubMed2000

Positron emission tomography scanning in malignant melanoma.

BACKGROUND: Several recent studies have demonstrated the low yield of anatomically based computed tomography scans in evaluating Stage III (American Joint Committee on Cancer) patients with malignant melanoma. The purpose of this study was to investigate the efficacy and clinical utility of functionally based positron emission tomography (PET) scans in the same patient population. METHODS: A prospective evaluation of 106 whole body PET scans obtained after injection of 2-fluorine-18, 2-fluoro-2-deoxy-D-glucose (FDG) was performed in 95 patients with clinically evident Stage III lymph node and/or in-transit melanoma. Areas of abnormality on FDG PET scanning were identified visually as foci of increased metabolic activity compared with background, and all positive foci were assessed pathologically. RESULTS: In this patient population, there were 234 areas that were evaluated pathologically of which 165 were confirmed histologically to be melanoma. PET scanning identified 144 of the 165 areas of melanoma for a sensitivity of 87.3%. The 21 areas of melanoma that were missed included 10 microscopic foci, 9 foci less than 1 cm, and 2 foci greater than 1 cm. There were 39 areas of increased PET activity that were not associated with malignancy for a 78.6% predictive value of a positive test. Of the 39 false-positive areas (false-positive rate of 56.5%), 13 could be attributed to recent surgery, 3 to arthritis, 3 to infection, 2 to superficial phlebitis, 1 to a benign skin nevus, and 1 to a colonic polyp. Pathologic evaluation of the remaining false-positive areas failed to reveal a definitive etiology for their increased activity on PET scan. With the application of pertinent clinical information, the predictive value of a positive PET scan could be improved to 90. 6%. The specificity of PET scanning in this study was only 43.5% because very few prophylactic lymph node dissections were performed. Thirty-six of the total 183 abnormal areas (19.7%) on PET scanning proved to be unsuspected areas of metastatic disease. These findings led to a change in the planned clinical management in patients after 16 of the 106 PET scans (15.1%). CONCLUSIONS: FDG PET scanning can be helpful in managing patients with Stage III melanoma in whom further surgery is contemplated. Although false-positive areas are not uncommon, PET scans did change the management of patients 15% of the time. PET's inability to identify microscopic disease suggests that it is of limited use in evaluating patients with Stage I-II disease.

Fluorodeoxyglucose F18↗
PubMed2000

[Glitazones (thiazolidinedione)].

Insulin resistance is the major defect in type 2 diabetes. Troglitazone is the first of a new class of drugs, the thiazolidinediones (TZD) with insulin sensitising actions. The TZD activate PPAR gamma (Peroxisome Proliferator Activated Receptor gamma). In clinical trials, the TZD decrease plasma glucose, plasma insulin and Hb A1C. Moreover they are synergistic with the glucose lowering drugs (biguanides and sulfonylureas) and with insulin therapy. The TZD also decrease triglycerides and increase HDL cholesterol, while reducing LDL oxidation. Few side effects have been reported but concerns persist about their safety. Hepatic dysfunction is seen in about 2% of the patients receiving troglitazone, leading sometimes to liver failure. This potentially lethal side effect appears to be less frequent with the second generation TZD, rosiglitazone and pioglitazone. Drug interactions, fluid retention, induction of colon polyps are other potential unwanted effects. This new class of drugs could play an important role in diabetes therapy, if clinical trials prove their long term efficacy and safety.

Animals↗
PubMed2000

Exisulind Cell Pathways.

Cell Pathways has developed exisulind (Aptosyn), an oral apoptosis modulator and cGMP phosphodiesterase inhibitor, for the potential treatment of several oncologic indications including precancerous adenomatous polyposis coli (APC), also known as familial adenomatous polyposis (FAP), precancerous sporadic colonic polyps, cervical dysplasia and the prevention of tumor recurrence in prostate and breast cancer. An NDA filing for the treatment of precancerous APC, for which the US FDA designated exisulind a Fast Track product in July 1998, was initially expected in March 1999 [291313]. However, in January of the same year the company stated that it anticipated a delay in the NDA filing. The decision was based on unsatisfactory phase III data [308912], [313124]. In June 1999, the company completed analysis of the phase III trial data [328000] and the NDA was submitted in August 1999. An NDA was accepted for review by the FDA in October 1999 for the treatment of APC [328000], [338007], [344721], after data from three additional trials were submitted to the FDA in support of the NDA. At this time phase II/III trials were also ongoing for prostate and breast cancer recurrence [287250], [326795]. Approval for the indication of FAP had been expected by the end of 2000 [365737] but in September 2000 the FDA completed its initial review and advised Cell Pathways that exisulind will not be approved at this time. Cell Pathways has received a 'non-approvable' letter and intends to advise the FDA of its intent to amend the NDA and to request a meeting to address the deficiencies in the NDA [383249], [383560]. The first of the three additional trials submitted to the FDA in October 1999 was a 6-month, open-label trial involving 48 of the patients who completed a phase II/III study of exisulind in early 1999. After 6 months of treatment with exisulind, 25 patients who had previously been taking placebo experienced a 50% reduction in polyp formation. The patients continuing treatment with exisulind exhibited a further 50% reduction from their already reduced rate of polyp formation [344991]. The second study was an extension study of 11 patients who participated in a 6-month, open-label, phase I/II, dose-ranging, safety and efficacy trial. As of October 1999, these patients were still on therapy and had been receiving exisulind for between 36 and 50 months. They had all experienced statistically significant reductions in polyp formation rates [344991]. The third study was a double-blind, placebo-controlled safety study of 26 patients. All patients exhibited a trend of reduced new polyp formation when compared to placebo. Exisulind was generally well-tolerated by all patients during the course of the studies [344991]. In July 2000, Cell Pathways signed a marketing and distribution agreement for Canada with Paladin Labs, allowing Paladin exclusive rights to commercialize exisulind within Canada [376072]. Also in July 2000, Cell Pathways announced that patents covering methods of identifying compounds that selectively stimulate apoptosis have been allowed in Europe and Japan. The patents describe the mechanism of action of Cell Pathways' SAANDs, including exisulind, and use of that knowledge in screening for new drugs [374888]. In January 1999, the company received US-05858694 covering the mechanism of action of exisulind [311504].

Animals↗
PubMed2001

Gardner's syndrome--the importance of early diagnosis: a case report and a review.

Gardner's syndrome (familial polyposis coli) is a genetic condition characterised by colonic polyps that carry a 100% risk of malignancy if untreated. Early diagnosis, in which an astute and knowledgeable dentist can play an essential role, is therefore of paramount importance. The presence of multiple unerupted teeth provides the dentist with a major pointer to the possible presence of this disease, which may be provisionally diagnosed on the detection of two other obvious features, namely osteomas and cutaneous lesions. This fact is clearly illustrated by the accompanying case report. Extracolonic manifestations increase the morbidity and make treatment more difficult. The presence of large desmoid tumours may be a serious complicating factor. Gardner's syndrome may be accompanied by adenomas of the stomach and duodenum and very rarely by malignant tumours of the central nervous system. Regular surveillance by means of colonoscopies must be carried out on all individuals suspected of having the disease in order to implement timeous life-saving prophylaxis.

Adult↗
PubMed2001

Nontruncating APC germ-line mutations and mismatch repair deficiency play a minor role in APC mutation-negative polyposis.

Familial adenomatous polyposis, an autosomal-dominantly inherited colorectal cancer predisposition syndrome, is caused by germ-line mutations in the adenomatous polyposis coli (APC) gene. Despite the use of different screening methods, studies worldwide fail to identify APC mutations in 20-50% of all familial adenomatous polyposis patients (APC mutation-negatives). In this study, missense mutations in the coding region of the APC gene, which would have been missed by the protein truncation test, as well as mutations in the APC promoter and the 3' untranslated region, were determined by the single nucleotide polymorphism discovery assay and direct DNA sequencing in 31 mutation-negative polyposis patients. Seventeen gene alterations were identified, whereof four (12.9%) represent possibly pathogenic germ-line mutations: silent A290T (promoter) and A8822G (3' untranslated region) as well as missense R99W and E1317Q (coding region). The 27 remaining, truly APC mutation-negative polyposis patients displayed a significantly later age at diagnosis compared with APC mutation carriers (46.1 versus 35.2 years; P < 0.01). APC mutation-negative individuals with >100 colonic polyps were more likely to present with extracolonic disease (P < 0.05) than those with <100. Assessment of microsatellite instability (MSI), a hallmark of mismatch repair deficiency, in 68 tumors from 21 truly APC mutation-negative patients, identified 4 (5.9%) unstable tubulo-villous adenomas (3 MSI-High and 1 MSI-Low), stemming from 4 (19%) unrelated individuals and likely to be caused by hMLH1 promoter hypermethylation. In conclusion, only a small proportion of APC germ-line mutation carriers is missed by the protein truncation test, and mismatch repair deficiency does not seem to substantially contribute to tumor development in APC mutation-negative polyposis patients.

3' Untranslated Regions↗