Biomedical subjects
Publications and source records attributed to J D Waye.
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Interest in risk factors for the recurrence of adenomatous polyps derives from the use of recurrent adenomas as surrogate end points in longitudinal studies of invasive colorectal cancer. In this case-control study, the effect of increased body mass index (BMI) on the risk of recurrent adenomas was investigated. Subjects consisted of patients seen at three colonoscopy practices in New York City, all of whom had a previous history of adenomas. On index colonoscopy, recurrent cases had an adenoma, whereas controls were normal. Men and women were analyzed separately, with different logistic models developed using backward elimination from a full model containing the covariates age at diagnosis, age-at-highest-weight, pack-years of smoking, activity level, energy intake, and fat and fiber intake. Men in the upper quartiles of BMI were found to be at greater risk of recurrent adenomas. In a model which controlled for age at diagnosis, age-at-highest-weight, activity level, pack-years of smoking and kilocalories, the estimated odds ratios were 2.2, 1.9 and 1.9 respectively for the second, third and fourth quartiles compared to the first quartile. Only the estimate for the second quartile was found to be statistically significant. No effect was observed for women, even in a model which controlled for age at diagnosis, age-at-highest-weight, pack-years and total fat. Obesity may play a role in adenoma recurrence. Confirmation of this finding would have important implications for possible prevention strategies in the future.
Events of reproductive life, such as parity and age at menarche, have been found in some but not all studies to be associated with risk for colorectal cancer in females. Because adenomatous polyps (adenomas) are precursors of colorectal cancer, we investigated whether reproductive variables were associated with colorectal adenomas. We conducted a case-control study among patients examined in three colonoscopy practices in New York City (NY, United States) from 1986 to 1988. Adenoma cases (n = 128) were defined as women who had an adenoma detected at the index colonoscopy with no history of inflammatory bowel disease, adenomas, or cancer. Controls (n = 283) were women with a normal index colonoscopy and no history of inflammatory bowel disease, adenomas, or cancer. The adjusted odds ratio (OR) for the association of early menarche (age less than 13 years) with adenomas was 0.6 (95 percent confidence interval = 0.4-0.9). Parity, history of spontaneous or induced abortion, infertility, type of menopause, age at menopause, use of oral contraceptives, and use of menopausal hormone replacement therapy were not associated statistically significantly with adenoma risk, although some possible trends were observed. Our findings do not implicate reproductive events, nulliparity, or overexposure to estrogens or to menstrual cycles as mechanisms of increased risk for colorectal neoplasia.
Recently published good quality data are the basis for this update. The newly reported studies include randomized trials, non-randomized cohort studies, and case-control studies; some of the data had mortality reduction as the endpoint. These guidelines, which were developed by the WHO Collaborating Center for the Prevention of Colorectal Cancer at Memorial Sloan-Kettering Cancer Center in conjunction with an International Advisory Committee, include primary prevention, screening of average-risk individuals, screening of individuals with heritable factors for colorectal cancer, surveillance of patients with colorectal polyps, and surveillance of patients with chronic ulcerative colitis. A list of papers reviewed for this update are cited, including recently published trials evaluating faecal occult-blood testing, case-control studies of sigmoidoscopy, the National Polyp study, and familial colon cancer studies. These guidelines will help inform patients and guide physicians in their approach to the prevention of colorectal cancer.
Upper intestinal endoscopy is a well-accepted method for evaluation of the esophagus, stomach, and duodenum. The techniques are standardized and extremely safe. The therapeutic capability for control of gastrointestinal hemorrhage is a major advance in the treatment of gastrointestinal bleeding. Endoscopic ultrasound is useful in the staging of upper intestinal malignancies. Above all, the ability to directly visualize the mucosal lining, to obtain biopsies, and to remove polyps has made endoscopy a primary tool for investigation of upper gastrointestinal pathology.
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Adenomatous polyps (hereinafter referred to as adenomas) are known precursors of colorectal cancer. Cigarette smoking has been associated with adenomas but not with colorectal cancer, while alcohol and fat intake have been associated with both adenomas and cancer in some studies. Approximately 30 percent of patients with resected adenomas develop another adenoma within three years. This case-control study explores the association of cigarette smoking with adenoma recurrence. Between April 1986 and March 1988, we administered a questionnaire to colonoscoped patients aged 35 to 84 years in three New York City (NY, USA) practices. We compared 186 recurrent polyp cases (130 males, 56 females) and 330 controls (187 males, 143 females) who had a history of polypectomy but normal follow-up colonoscopy, by cigarette-smoking pack-years adjusted for possible confounders. Risk for a metachronous or recurrent adenoma was significantly greater in the highest quartile of smokers than in never-smokers among both men (odds ratio [OR] = 1.8, 95 percent confidence interval [CI] = 1.0-3.4) and women (OR = 3.6, CI = 1.7-7.6). Adjustment for time since smoking cessation reduced risk only slightly, as did adjustment for dietary fat intake, which itself remained significant. No association was found between alcohol intake and risk of recurrence. Cigarette smokers appear to have an elevated risk of adenoma recurrence that is not eliminated entirely by smoking cessation. Intervention trials that use adenoma recurrence as an endpoint should take smoking into account.
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We report three patients with chronic ulcerative colitis and colonic strictures that were found to harbor advanced adenocarcinomas despite previous endoscopic examinations that had failed to demonstrate dysplasia or carcinoma. This experience calls into question the reliability of endoscopic monitoring of the subset of ulcerative colitis patients with strictures. Review of the literature supports the thesis that the management of these patients requires a high index of suspicion of malignancy, and should include timely consideration of surgery. It is suggested that evaluation of the effectiveness of endoscopic surveillance programs for patients with ulcerative colitis should consider the subset of patients with strictures as a separate cohort.
BACKGROUND: The current practice of removing adenomatous polyps of the colon and rectum is based on the belief that this will prevent colorectal cancer. To address the hypothesis that colonoscopic polypectomy reduces the incidence of colorectal cancer, we analyzed the results of the National Polyp Study with reference to other published results. METHODS: The study cohort consisted of 1418 patients who had a complete colonoscopy during which one or more adenomas of the colon or rectum were removed. The patients subsequently underwent periodic colonoscopy during an average follow-up of 5.9 years, and the incidence of colorectal cancer was ascertained. The incidence rate of colorectal cancer was compared with that in three reference groups, including two cohorts in which colonic polyps were not removed and one general-population registry, after adjustment for sex, age, and polyp size. RESULTS: Ninety-seven percent of the patients were followed clinically for a total of 8401 person-years, and 80 percent returned for one or more of their scheduled colonoscopies. Five asymptomatic early-stage colorectal cancers (malignant polyps) were detected by colonoscopy (three at three years, one at six years, and one at seven years). No symptomatic cancers were detected. The numbers of colorectal cancers expected on the basis of the rates in the three reference groups were 48.3, 43.4, and 20.7, for reductions in the incidence of colorectal cancer of 90, 88, and 76 percent, respectively (P < 0.001). CONCLUSIONS: Colonoscopic polypectomy resulted in a lower-than-expected incidence of colorectal cancer. These results support the view that colorectal adenomas progress to adenocarcinomas, as well as the current practice of searching for and removing adenomatous polyps to prevent colorectal cancer.
BACKGROUND: The identification and removal of adenomatous polyps and post-polypectomy surveillance are considered to be important for the control of colorectal cancer. In current practice, the intervals between colonoscopies after polypectomy are variable, often a year long, and not based on data from randomized clinical trials. We sought to determine whether follow-up colonoscopy at three years would detect important colonic lesions as well as follow-up colonoscopy at both one and three years. METHODS: Patients were eligible if they had one or more adenomas, no previous polypectomy, and a complete colonoscopy and all their polyps had been removed. They were randomly assigned to have follow-up colonoscopy at one and three years or at three years only. The two study end points were the detection of any adenoma, and the detection of adenomas with advanced pathological features (defined as those > 1 cm in diameter and those with high-grade dysplasia or invasive cancer). RESULTS: Of 2632 eligible patients, 1418 were randomly assigned to the two follow-up groups, 699 to the two-examination group and 719 to the one-examination group. The percentage of patients with adenomas in the group examined at one and three years was 41.7 percent, as compared with 32.0 percent in the group examined at three years (P = 0.006). The percentage of patients with adenomas with advanced pathological features was the same in both groups (3.3 percent). CONCLUSIONS: Colonoscopy performed three years after colonoscopic removal of adenomatous polyps detects important colonic lesions as effectively as follow-up colonoscopy after both one and three years. An interval of at least three years is recommended before follow-up colonoscopy after both one and three years. An interval of at least three years is recommended before follow-up examination after colonoscopic removal of newly diagnosed adenomatous polyps. Adoption of this recommendation nationally should reduce the cost of post-polypectomy surveillance and screening.
OBJECTIVE: To investigate the association of dietary factors with the incidence and recurrence of colorectal adenomatous polyps. DESIGN: Two case-control studies. SETTING: Three university-based colonoscopy practices in New York City. PATIENTS: For the incidence study, 286 patients with pathologically confirmed incident adenomatous polyps (162 men and 124 women) were compared with 480 controls (210 men and 270 women) with no current or previous neoplasia. For the recurrence study, 186 patients with recurrent polyps (130 men and 56 women) were compared with 330 controls (187 men and 143 women). These patients had a history of polyps but no current neoplasia. MEASUREMENTS: Structured interviews using the Block food frequency questionnaire were conducted on all participants and were compared over quartiles of crude nutrient intake of total and saturated fat; fiber; protein; carbohydrates; carotene; vitamins A, C, and E; and various food groups. Data were adjusted for age, Quetelet index, and caloric intake by multiple logistic regression for men and women separately. RESULTS: For incident polyps, elevated adjusted odds ratios (high to low quartile) for women were found for saturated fat (odds ratio, 2.3; 95% CI, 0.9 to 5.8) and the ratio of red meat to chicken and fish intake (odds ratio, 1.9; CI, 1.0 to 3.6). Protective associations were observed for fish and chicken (odds ratio, 0.6; CI, 0.3 to 1.2) and vitamin A intake (odds ratio, 0.4; CI, 0.2 to 0.9). Among women, recurrent polyps showed an association with total dietary fat (odds ratio, 4.4; CI, 1.0 to 19.5), saturated fat (odds ratio, 3.8; CI, 1.0 to 14.9; P = 0.15 for the trend), and total fiber (odds ratio, 0.2; CI, 0.1 to 0.5; P = 0.01) and a borderline association with carbohydrates (odds ratio, 0.3; CI, 0.1 to 1.3; P = 0.10). No consistent relations were observed for men, although increased caloric intake increased the risk for incidence and recurrence in both men and women. CONCLUSIONS: These findings are consistent with previously described relations between diet and the incidence of colon cancer and suggest that, at least in women, dietary modification may be warranted in patients diagnosed with polyps.
The possible association of colorectal adenomatous polyps, a precursor lesion for colorectal cancer, with cigarette smoking, alcohol consumption, and coffee and caffeine consumption was investigated in a case-control study. Between April 1986 and March 1988, 271 cases of patients with pathologically confirmed incident colorectal adenomatous polyps and 457 control subjects were collected from three colonoscopy practices in New York City. Information on exposure was obtained by structured interviews. After adjustment of age, statistically significant odds ratios (highest-lowest quartile) were found for cigarette smoking in males (2.2; 95% confidence interval (CI), 1.2 to 3.8) and coffee consumption in females (2.0%; 95% CI, 1.0 to 3.9). No significant associations were obtained for cigarette smoking in females, for coffee consumption in males, or for alcohol or caffeine consumption. After adjustments for alcohol, coffee, and caffeine consumption, the association of adenomas with cigarette smoking remained in males and significant associations were also observed in subcategory analysis for both left-side and right-side adenomatous polyps. Adjustment for cigarette smoking eliminated the association between colorectal adenomatous polyps and coffee consumption in females. Cigarette smoking appears to be a significant risk factor for colorectal adenomatous polyps in males.
Complications can occur following therapeutic endoscopy. The most serious complication is bleeding, which occurs in 1.4% of all colonoscopic polypectomies. Perforation occurs in 0.3% of patients and postpolypectomy coagulation syndrome is seen in 1% of all patients following polypectomy. Bleeding is a dramatic complication, but most cases can be handled colonoscopically without the need for surgery or angiography. For patients who present with delayed bleeding (2% of all patients), emergency colonoscopy should be performed if the patient has active ongoing bleeding. Once a patient stops bleeding, rebleeding is not commonly seen. A schema is given for polypectomy when the patient is on anticoagulants. Other postpolypectomy syndromes discussed include pain, a contrecoup burn of the wall, and the transmural burn. Most of these resolve without any therapy. A review of the literature and personal comments are included in this article, which provides practical guidelines for postpolypectomy complications.
OBJECTIVES: To assess the clinical yield of colonoscoping in patients who present with rectal bleeding, persistent abdominal pain, or change in bowel habits in the absence of bleeding. DESIGN: A prospective study of colonoscopy patients. SETTING: Three colonoscopy practices in New York City between April 1986 and November 1989. PATIENTS: Eight hundred sixty-one patients with rectal bleeding, 113 patients with abdominal pain, 154 with change in bowel habits, and 44 patients with both abdominal pain and bowel change. MAIN RESULTS: Of 861 patients with rectal bleeding, 293 (33.6%) had colonic neoplasia (8.6% cancer and 25% adenomatous polyps). In patients who had colonoscopy because of abdominal pain (n = 113), change in bowel habits (n = 154), or both abdominal pain and bowel change (n = 44), respectively 25 (22.1%), 42 (27.3%), and 10 (22.7%) had colonic neoplasms. If one looks at significant neoplasia (cancer or adenomas > 1 cm), then the findings in rectal bleeders were 14.5%, whereas the abdominal pain, change in bowel habits, and both groups had 7.1%, 7.1%, and 13.6%, respectively. Patients with rectal bleeding were more likely to have multiple adenomas than those with nonbleeding symptoms (p < 0.05). CONCLUSIONS: Patients with persistent nonbleeding GI symptoms, including abdominal pain and change in bowel habits, have almost as high a yield of colorectal neoplasia as those with rectal bleeding.
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The National Polyp Study (NPS) is a multicenter prospective randomized trial designed to evaluate follow-up surveillance strategies in patients who have undergone polypectomy for the control of large bowel cancer. The study design was developed by a joint research committee from American Gastroenterological Association, the American Society for Gastrointestinal Endoscopy, and the American College of Gastroenterology. Subjects who met the eligibility criteria were randomized into two different treatment arms. Eligibility criteria included: removal of one or more adenomas; complete colonoscopy; no prior polypectomy, inflammatory bowel disease, or familial polyposis; and no history of colon cancer. The treatment arms consisted of a frequent follow-up (1 and 3 years after initial polypectomy) and a less frequent follow-up (3 years). Follow-up examinations included fecal occult blood tests, air-contrast barium enema, and colonoscopy. The latter was done on 9112 referred patients at the seven participating centers from November 1980 until February 1990 who had no history of polypectomy, colon cancer, familial polyposis, or inflammatory bowel disease. Of these patients, 4763 (52.3%) had no polyps; 549 (6.0%) had an invasive cancer; 776 (8.5%) had nonadenomatous polyps; 208 (2.3%) had incomplete examinations; 184 (2.0%) had other findings; and 2632 (28.9%) had one or more adenomas, of which 1418 (53.9%) were randomized to one of the two treatment arms. This article reports the background, rationale, objectives, methods, and organization of this study and includes patient characteristics on initial presentation. Future data provided by the NPS may help in the development of recommendations for surveillance guidelines for such patients. This study also provides a framework to address questions regarding the natural history of adenomas and their relationship with colorectal cancer.