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Biomedical subjects

A D Spigelman

Publications and source records attributed to A D Spigelman.

At least 19 recordsLinked to original sources
PubMed2002

Duodenal cancer in patients with familial adenomatous polyposis (FAP): results of a 10 year prospective study.

BACKGROUND: Duodenal cancer is one of the leading causes of death in familial adenomatous polyposis (FAP) patients. An endoscopic surveillance programme was therefore initiated in 1988, the outcome of which is described in this paper. METHODS: We report the 10 year follow up of 114 patients with FAP who were prospectively screened for the presence and severity of duodenal adenomas. RESULTS: Six of 114 patients (median age 67 years) developed duodenal adenocarcinoma. Four of these were from 11 patients who originally had Spigelman stage IV disease (advanced duodenal polyposis), which gives a 36% risk within this group of developing cancer. One case of duodenal cancer arose from 41 patients who originally had stage III disease (2%) and one cancer arose from 44 patients with original stage II disease (2%). All six patients have died: five were inoperable and one had recurrence three years after a pancreaticoduodenectomy. There was no association between duodenal cancer and site of germline mutation of the APC gene. CONCLUSIONS: Surveillance for duodenal adenocarcinoma and subsequent early referral for curative surgery has not been effective. Selection of patients with advanced but benign (Spigelman stage IV) duodenal polyposis for prophylactic pancreaticoduodenectomy should therefore be considered and can now be justified on the basis of these results. More comprehensive endoscopic surveillance of high risk (stage III and IV) patients is needed in an attempt to avoid underestimating the severity of duodenal polyposis, and to evaluate the role of endoscopic therapy in preventing advanced disease.

Adenocarcinoma↗
PubMed2001

The intention to hasten death: a survey of attitudes and practices of surgeons in Australia.

OBJECTIVE: To determine attitudes among surgeons in Australia to assisted death, and the proportion of surgeons who have intentionally hastened death with or without an explicit request. DESIGN: Anonymous, cross-sectional, mail-out survey between August and November 1999 PARTICIPANTS: 683 out of 992 eligible general surgeons (68.9% response rate). MAIN OUTCOME MEASURES: Proportion of respondents answering affirmatively to questions about administering excessive doses of medication with an intention to hasten death. RESULTS: 247 respondents (36.2%; 95% CI, 32.6%-39.9%) reported that, for the purpose of relieving a patient's suffering, they have given drugs in doses that they perceived to be greater than those required to relieve symptoms with the intention of hastening death. More than half of these (139 respondents; 20.4% of all respondents; 95% CI, 17.4%-23.6%) reported that they had never received an unambiguous request for a lethal dose of medication. Of all respondents, only 36 (5.3%; 95% CI, 2.9%-6.1%) reported that they had given a bolus lethal injection, or had provided the means to commit suicide, in response to an unambiguous request. CONCLUSIONS: More than a third of surgeons surveyed reported giving drugs with an intention to hasten death, often in the absence of an explicit request. However, in many instances, this may involve the use of an infusion of analgesics or sedatives, and such actions may be difficult to distinguish from accepted palliative care, except on the basis of the doctor's self-reported intention. Legal and moral distinctions based solely on a doctor's intention are problematic.

Adult↗
PubMed2001

Randomized, placebo-controlled trial of gastric acid-lowering therapy on duodenal polyposis and relative adduct labeling in familial adenomatous polyposis.

PURPOSE: Bile has been implicated in the pathogenesis of duodenal polyps in patients with familial adenomatous polyposis. In vitro experiments have shown that familial adenomatous polyposis bile is capable of producing DNA adducts. This effect can be ameliorated by increasing the pH of the incubate. The aim of this double-blind randomized placebo-controlled trial was to examine the effect of oral ranitidine on duodenal polyposis in a group of patients with familial adenomatous polyposis. METHODS: Twenty-six patients with familial adenomatous polyposis were randomly assigned to ranitidine 300 mg daily or placebo for six months after baseline endoscopy. Polyp counts were performed and biopsy specimens taken to detect DNA adducts by 32P-postlabeling. RESULTS: No difference was seen in polyp numbers (P = 0.9) or relative adduct labeling (P = 0.7) after treatment with ranitidine or placebo. DISCUSSION: Acid suppression therapy does not seem to improve duodenal polyposis despite in vitro findings. On the other hand, ranitidine does not exacerbate actual (or markers of) neoplasia in this highly tumor-prone condition.

Adenomatous Polyposis Coli↗
PubMed2001

Relationship between APC genotype, polyp distribution, and oral sulindac treatment in the colon and rectum of patients with familial adenomatous polyposis.

PURPOSE: Familial adenomatous polyposis is an inherited colorectal cancer syndrome characterized by the presence of multiple adenomatous colorectal polyps. Molecular studies have revealed that germline mutations in the APC gene are the underlying cause of the disease. The nonsteroidal anti-inflammatory agent sulindac has been shown to reduce the number of colorectal adenomas. Most sulindac trials in the large bowel have focused on the distal colon and relatively little is known about its effect on the proximal colon. Moreover, it is unknown whether the site of the APC mutation affects the efficacy of sulindac. METHODS: This study investigated whether there were regional differences in the effect of sulindac on the colon and whether response to sulindac was dependent on the site of mutation in the APC gene. In an open prospective study 17 patients with familial adenomatous polyposis were treated with 300 mg oral sulindac daily for four months followed by a washout phase of six months. Ten of the patients had an intact colon and seven had rectal stumps only. The number, size, and the degree of dysplasia of the adenomas were evaluated by colonoscopy at entry, end of treatment and end of the study. RESULTS: Overall, a statistically significant decrease in the number of adenomas was observed (120 +/- 112 to 28 +/- 64, P = 0.007). After cessation of sulindac treatment the number of adenomas increased to 48 +/- 44.5, but remained significantly lower than the values observed at baseline. In the ten patients with intact colons, adenomas decreased by sevenfold in the proximal colon (103 +/- 73 to 15.1 +/- 47.4, P = 0.011) and twofold in the distal colon (80 +/- 52 to 29.6 +/- 37.2, P = 0.005). The size of adenomas and the grade of dysplasia also decreased. No correlation could be seen between the APC mutation site and the response to treatment. CONCLUSION: These data indicate that sulindac reduces the number of adenomas in the entire colon and that the effect seems to be more pronounced in the proximal colon.

Adenomatous Polyposis Coli↗
PubMed2001

Familial adenomatous polyposis: more evidence for disease diversity and genetic heterogeneity.

Familial adenomatous polyposis (FAP) is characterised by the presence of profuse colonic carpeting of adenomas throughout the entire colon and rectum. The genetic basis of FAP has been shown to be primarily associated with germline mutations in the APC gene. Notwithstanding, several reports have been published indicating that there is genetic heterogeneity in FAP and that the most likely explanation is the existence of another gene. In this report we further delineate the genotype/phenotype correlation in families that harbour germline mutations in the APC gene and identify some previously unreported changes in the APC gene which predispose to an attenuated disease phenotype. From 53 index patients diagnosed with either FAP or attenuated FAP, 27 harboured changes in the APC gene. The remaining 26 patients were further subgrouped according to their colonic phenotype. There were nine patients with a mixed hyperplastic/adenomatous colonic phenotype and there were 17 patients with an adenomatous colonic phenotype. Evaluation of the disease characteristics of these patients and their families is presented which may aid in the identification of new genes associated with colonic polyposis.

Adenomatous Polyposis Coli↗
PubMed2000

Hereditary nonpolyposis colorectal cancer in 95 families: differences and similarities between mutation-positive and mutation-negative kindreds.

Hereditary nonpolyposis colorectal cancer (HNPCC) describes the condition of a disparate group of families that have in common a predisposition to colorectal cancer in the absence of a premalignant phenotype. The genetic basis of this disease has been linked to mutations in genes associated with DNA mismatch repair. A large proportion of families harbor changes in one of two genes, hMSH2 and hMLH1. Approximately 35% of families in which the diagnosis is based on the Amsterdam criteria do not appear to harbor mutations in DNA-mismatch-repair genes. In this report we present data from a large series of families with HNPCC and indicate that there are subtle differences between families that harbor germline changes in hMSH2 and families that harbor hMLH1 mutations. Furthermore, there are differences between the mutation-positive group (hMSH2 and hMLH1 combined) of families and the mutation-negative group of families. The major findings identified in this study focus primarily on the extracolonic disease profile observed between the mutation-positive families and the mutation-negative families. Breast cancer was not significantly overrepresented in the hMSH2 mutation-positive group but was overrepresented in the hMLH1 mutation-positive group and in the mutation-negative group. Prostate cancer was not overrepresented in the mutation-positive groups but was overrepresented in the mutation-negative group. In age at diagnosis of colorectal cancer, there was no difference between the hMSH2 mutation-positive group and the hMLH1 mutation-positive group, but there was a significant difference between these two groups and the mutation-negative group.

Adolescent↗
PubMed2000

Development of duodenal cancer in a patient with familial adenomatous polyposis.

A Japanese woman with familial adenomatous polyposis in whom a duodenal ampullary adenoma underwent malignant change during a 10-year follow-up period is reported. After restorative proctocolectomy in 1989, and extensive small bowel resection for desmoid disease in 1991, regular surveillance duodenoscopies, including three to nine biopsies (mean, 4.8) were performed annually or biannually. Until 1995, the endoscopic findings of duodenal polyposis (including an ampullary polyp) did not progress and the histopathology did not worsen. In 1996, there was an increase in the number and size of the duodenal polyps, and the ampulla of Vater looked enlarged. Open surgery was discussed but not proceeded with because of the risk for short bowel syndrome. In January 1998, she was admitted with a diagnosis of acute pancreatitis. Duodenoscopy and radiological examination revealed that an advanced ampullary cancer had developed, and histopathology revealed a well-differentiated adenocarcinoma. Multiple hepatic metastases and ascites led to her death, in June, 1998. This in-vivo demonstration of the adenoma-carcinoma sequence highlights current limitations in the surveillance and treatment of duodenal lesions.

Adenomatous Polyposis Coli↗
PubMed2000

Gastroduodenal lesions in familial adenomatous polyposis.

Prophylactic colectomy is generally recommended for patients with familial adenomatous polyposis (FAP) who are inevitably affected with large bowel cancer. After prophylactic colectomy has been performed, gastrointestinal malignancy is the leading cause of death. Duodenal adenomas are found in patients with FAP and the adenoma-carcinoma sequence exists in the FAP duodenum, suggesting that treatment of duodenal polyps might be beneficial. Several methods of treatment for duodenal lesions in patients with FAP have been reported, but the current treatment options are not ideal. The nonsteroid anti-inflammatory drugs, sulindac and aspirin, are used for chemoprevention, while recently developed cyclooxygenase-2 inhibitors may be of some use in the future. Endoscopic polypectomy has been attempted for duodenal polyps and open surgical polypectomy has proven to be effective for selected patients. Photodynamic therapy and Argon plasma coagulation may be suitable to treat carpeted polyposis. New methods of duodenal resection, such as pancreas-preserving duodenectomy and pylorus-preserving pancreaticoduodenectomy, might be considered for severe duodenal polyposis; however, because prophylactic duodenal surgery has been considered too aggressive, surveillance duodenoscopy is usually performed to detect duodenal cancer at an early stage.

Adenoma↗
PubMed2000

A survey of surgical audit in Australia: whither clinical governance?

A postal survey was undertaken to determine the extent of surgical audit in Australian public hospitals in the context of clinical governance. Participants were 88 surgical units from 74 Australian public hospitals in 1998 with more than 70 beds. The main outcome measures were performance of audit, methods used, frequency, documentation and perceived adequacy of resources and comparison of performance with Royal Australasian College of Surgeons requirements for re-certification. The main findings were that most units performed audit, but over two-thirds declared that they had insufficient resources to conduct audit according to College requirements, while a substantial proportion did not comply with other published guidelines for the conduct of audit meetings. The conclusion from this survey is that surgical audit will be unable to play its part in quality initiatives inherent in the clinical governance concept unless appropriately resourced.

Australia↗
PubMed1998

Malignant change in a duodenal adenoma in familial adenomatous polyposis: report of a case.

Patients with FAP (familial adenomatous polyposis) are known to be at high risk for duodenal cancer. Although the adenoma-carcinoma sequence is thought to exist in the duodenum, clinical observation of the development of duodenal adenoma to cancer has rarely been reported. We outline a 44-yr-old postcolectomy man with FAP who underwent regular gastroduodenoscopy annually or biannually and was found to be harboring duodenal ampullary cancer 5 yr after colectomy. Endoscopic and pathological examination of the ampullary lesion during these 5 yr revealed progression of pathology from adenoma to carcinoma. Pathology of the surgical specimen confirmed ampullary cancer. This in vivo demonstration of the adenoma-carcinoma sequence highlights the current limitations of duodenal surveillance in FAP.

Adenoma↗
PubMed1997

The use of 32P-postlabelling in studies of the nature and origin of DNA adducts formed by bile from patients with familial adenomatous polyposis and from normal patients.

32P-postlabelling is a highly sensitive technique for the detection of DNA adducts. It is unique in that it requires no prior knowledge of the nature of adducts or adduct-forming species under investigation. In the past, we have used this technique to investigate the role of bile in the production of foregut adenomas in patients with familial adenomatous polyposis (FAP). We have found that bile contains constituents that form DNA adducts directly, and after metabolic activation, and that the bile of FAP patients has an increased capacity for adduct formation with DNA in vitro, in human cell lines in culture, and in the gastrointestinal tract of rats given bile by gavage. The sensitivity of 32P-postlabelling is such that it is difficult to obtain sufficient quantities of DNA adducts for chemical analysis. The nature of the adducts produced by bile, or of the bile constituents that produce them is as yet undetermined. In the present studies, we have combined 32P-postlabelling with indirect methods to gain some insight into the nature of DNA adducts produced by bile and the properties of the reactive species that form them. Firstly, bile was incubated with synthetic monodeoxynucleotides or polydeoxynucleotides. Bile did not produce adducts when incubated with monodeoxynucleotides or single-stranded polydeoxynucleotides. However, it did produce adducts when incubated with double-stranded polydeoxynucleotides. The pattern of adduct formation suggested that human bile forms a mixture of adenine and guanine adducts. Secondly, bile was fractionated by extraction with blue cotton or with neutral, acid or alkaline organic solvent. Blue cotton, which efficiently and selectively absorbs mutagens having 3 or more fused aromatic rings, did not absorb biliary constituents that could form adducts with DNA in vitro or with DNA of MCL-5 cells, a metabolically competent human cell line. This suggests that biliary DNA adduct precursors are polar compounds that contain fewer than 3 aromatic rings or are non-aromatic. Acidic organic extracts of human bile produced much higher levels of DNA adducts in vitro or with DNA of MCL-5 cells than did neutral or alkaline organic extracts, suggesting that constituents of bile that form DNA adducts are acidic in nature.

Adenomatous Polyposis Coli↗