Pathologic Features of Initial Adenomas as Predictors for Metachronous Adenomas of the Rectum
04 Nov 1998-Journal of the National Cancer Institute (Oxford University Press)-Vol. 90, Iss: 21, pp 1661-1665
TL;DR: The risk of metachronous adenomas is closely related to the pathology of initial adenomatous polyps, thus allowing identification of a high-risk group of adenoma patients for close surveillance after their initial polypectomy.
Abstract: Background Colorectal cancer is the third most common cancer in the world, arising mostly from pre-existing adenomatous polyps (adenomas) of the large bowel. Patients with colorectal adenomas are at increased risk of colorectal cancer because of a high recurrence rate for adenomas. We followed a cohort of 1490 patients with rectal adenomas to determine whether recurrence might be related to pathologic characteristics of the initial adenomas. Methods The patients were identified in Haining County, China, from 1977 through 1978 by means of examination with a 15-cm rigid sigmoidoscope. They were followed by endoscopic examination at years 2, 4, 6, 11, and 16 after their initial polypectomy. New adenomas in the rectum were identified in 280 patients in these follow-up examinations. Results Statistically significant twofold to threefold elevated risks of metachronous (recurrent) adenomas were observed for patients who had more than two initial adenomas or whose most advanced initial adenoma was more than 1.0 cm in size, was of villous/tubulovillous type, or showed moderate to severe dysplasia. Much stronger associations were observed for advanced metachronous neoplasms, which are defined as cancers or adenomas with severe dysplasia, with multivariate adjusted relative risks (95% confidence interval) of 4.2 (1.8-9.9) for a large initial adenoma (>1.0 cm), 8.1 (4.2-15.6) for villous/tubulovillous architecture, and 14.4 (5.0-41.3) for severe dysplasia. In particular, patients who had a large (>1.0 cm) adenoma with severe dysplasia at baseline had a relative risk of 37 (7.8-174.7) of developing advanced metachronous neoplasms compared with patients who had small adenoma(s) with mild dysplasia. Conclusions The risk of metachronous adenomas is closely related to the pathology of initial adenomas, thus allowing identification of a high-risk group of adenoma patients for close surveillance after their initial polypectomy.
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TL;DR: This study provides support for the use of a novel risk score as a clinical predictor of ACA recurrence after colon polypectomy with an internal 10-fold cross validation by means of bootstrap sampling.
Abstract: Development and validation of a risk score for advanced colorectal adenoma recurrence after endoscopic resection
15 citations
TL;DR: A systematic review and meta‐analysis was conducted to identify personal, lifestyle, and tumor‐related risk factors for metachronous colorectal cancer (CRC) and polyp.
Abstract: Background and aim We conducted a systematic review and meta-analysis to identify personal, lifestyle, and tumor-related risk factors for metachronous colorectal cancer (CRC) and polyp. Methods Relevant studies were identified by searching MEDLINE, Web of Science and Cochrane Central Register through 15 May 2016. Estimates for associations were summarized using random effects models. Results Fifty-five studies were included in the review. For individuals who had a CRC resection, having a synchronous polyp was a risk factor for metachronous CRC or polyp (relative risk [RR], 2.04; 95% confidence interval [CI], 1.48-2.82) and having a synchronous CRC (RR, 1.90; 95% CI, 1.25-2.91) and proximally located CRC (RR, 2.12; 95% CI, 1.24-3.64) were risk factors for metachronous CRC. For individuals who had a polypectomy, larger size (RR, 4.26; 95% CI, 2.11-8.57) or severe dysplasia of the initial polyp (RR, 5.15; 95% CI, 2.02-13.14), and having a synchronous polyp (RR, 2.52; 95% CI, 1.35-4.73) were risk factors for metachronous CRC; and a family history of CRC (RR, 1.90; 95% CI, 1.26-2.87), having a synchronous polyp (RR, 2.47; 95% CI, 1.74-3.50) and a larger size (RR, 1.49; 95% CI, 1.03-2.15) and proximal location of the initial polyp (RR, 1.20; 95% CI, 1.02-1.40) were risk factors for metachronous polyp. Meta-regression showed duration of follow-up was not a source of heterogeneity for most associations. There was no evidence that lifestyle factors were associated with metachronous CRC or polyp risk. Conclusion A comprehensive list of risk factors identified for metachronous CRC or polyp may have important clinical implications.
15 citations
TL;DR: Overall, AMACR expression was associated with the grade of dysplasia, as well as with the size and configuration of adenomas, i.e. the consensus risk factors applied to colorectal adenoma patient surveillance.
Abstract: AIM: To analyze α-methylacyl CoA racemase (AMACR) expression in relation to various dysplasia phenotypes and clinicopathological parameters of sporadic colorectal adenomas.
METHODS: Fifty-five cases of sporadic colorectal adenomas were categorized according to the Vienna classification for Gastrointestinal Neoplasia. These corresponded to a total of 98 different intra-lesion microscopic fields that were further independently assigned a histological grade based on the old nomenclature (mild, moderate, severe dyplasia and carcinoma in situ). AMACR expression was evaluated by immunohistochemistry and statistical analysis was performed to investigate possible associations with various clinicopathologic parameters of adenomas i.e. gender, age, localization, grade of dysplasia, size and configuration.
RESULTS: Patient age ranged from 41 to 84 years (mean 65 ± 13.2 years); 37 patients were males and 18 were females. Adenomas ranged in size between 0.5 and 30 cm (mean 2 ± 1.3 cm), including 18 tubular, 16 villous, 20 mixed or tubulovillous, and 1 giant sessile villous adenoma. AMACR expression was observed in 3 out of 16 (18.8%) of low-grade vs 23 out of 35 (62.8%) of high-grade lesions (P = 0.002). Most adenomas exhibiting high grade dysplasia with in situ carcinoma-like areas stained positive for AMACR (15/17 or 88.2%) as compared to adenomas with high grade dysplasia which contained severe dysplasia-like foci (6/15 or 40%), (P = 0.005). In AMACR positive adenomas featuring severe dysplasia-like or in situ carcinoma-like areas, AMACR staining was not necessarily observed in the in situ component. Positivity in intra-lesion of mild, moderate or severe dysplasia-like foci was more often encountered in adenomas harboring in situ, intramucosal or infiltrative carcinoma [21/33 (63.6%) vs 9/40 (22.5%), P 1 cm stained more frequently for AMACR than smaller ones [27/45 (60%) vs 2/10 (20%), P = 0.02]. Overall, AMACR expression was associated with the grade of dysplasia, as well as with the size and configuration of adenomas, i.e. the consensus risk factors applied to colorectal adenoma patient surveillance.
CONCLUSION: It may be worthy to further evaluate the possible use of AMACR as an additional risk factor for the assessment of colorectal adenoma patients.
13 citations
TL;DR: The distribution and characteristics of polyps removed in colonoscopy screening are described, finding most patients with adenomatous polyps in the right colon showed no synchronic adenomas on the left side, and most individuals undergoing CRC screening would have gone undetected if they had been explored with proctosigmoidoscopy.
Abstract: Background and study aimsBecause the relationship between distal and proximal colonic findings remains uncertain, controversy exists over whether proctosigmoidoscopy or colonoscopy is more suitable for colorectal cancer (CRC) screening. We aim to describe the distribution and characteristics of poly
13 citations
TL;DR: The recurrence rate of colorectal adenoma corrected by lowering the miss rate was lower than reported rates and the presence of multiple adenomas on initial colonoscopy was an important predictor of recurrence.
Abstract: Background/Aims: Although colorectal adenoma is reported to recur frequently, this may result from missing it at baseline. However, few studies of recurrence have considered the miss rate. This study evaluated the recurrence rate prospectively and clinical predictors of recurrence in colorectal adenoma after lowering the miss rate. Methods: The study population comprised 128 patients who underwent baseline colonoscopy with resection of colorectal adenomas. Re-examination to lower the miss rate was performed within 2 months. Follow-up colonoscopy to detect recurrence was done more than 1 year after removal. Results: The mean follow-up period was 35.1 months (range, 12 to 84 months). Thirty patients had a recurrent adenoma, for a recurrence rate of 23.4%. Older patients (over 60 years) had a two-fold greater risk of recurrence than younger patients (hazard ratio, 2.39; 95% confidence interval (CI), 1.16-4.90). Patients with three or four adenomas at baseline colonoscopy had a two-fold greater risk than those with one adenoma (hazard ratio, 2.44; 95% CI, 1.11-5.35). Patients with advanced adenoma had a two-fold greater risk than those with no advanced adenoma (hazard ratio, 2.88; 95% CI, 1.40-5.95). In multivariate analysis, only the presence of three or four adenomas independently predicted the recurrence of adenoma (hazard ratio, 3.19; 95% CI, 1.04-9.79). Conclusions: The recurrence rate of colorectal adenoma corrected by lowering the miss rate was lower than reported rates. The presence of multiple adenomas on initial colonoscopy was an important predictor of recurrence. (Korean J Intern Med 2009;24:196-202)
12 citations
References
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TL;DR: A model for the genetic basis of colorectal neoplasia that includes the following salient features is presented, which may be applicable to other common epithelial neoplasms, in which tumors of varying stage are more difficult to study.
11,576 citations
TL;DR: The results of the National Polyp Study 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.
Abstract: 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...
4,310 citations
TL;DR: Evidence is presented which suggests that most cancers of the colon and rectum have evolved through the polyp‐cancer sequence although the majority of adenomas do not become cancerous during a normal adult life span.
Abstract: The malignant potential of adenomas of the colon and rectum varies with size, histological type and grade of epithelial atypia. The adenomatous polyp is usually small and has a low malignant potential, whereas tumors with a villous structure are usually larger and have a much higher cancer rate. Severe atypia is more common in villous adenomas than in adenomatous polyps. Evidence is presented which suggests that most cancers of the colon and rectum have evolved through the polyp-cancer sequence although the majority of adenomas do not becoma cancerous during a normal adult life span. The slow evolution of the polyp-cancer sequence is stressed. The implications of the polyp-cancer sequence for the design of cancer prevention programmes and the study of the aetiology of large bowel cancer are discussed.
1,944 citations
TL;DR: The long-term risk of colorectal cancer after rigid-instrument sigmoidoscopy and polypectomy in 1618 patients with rectosigmoid adenomas who did not undergo surveillance was assessed, finding that surveillance may not be of value because the risk of cancer is so low.
Abstract: Background and Methods Surveillance by repeated colonoscopy is currently recommended for patients with colorectal adenomas. We assessed the long-term risk of colorectal cancer after rigid-instrument sigmoidoscopy and polypectomy in 1618 patients with rectosigmoid adenomas (tumors of the rectum or distal sigmoid colon) who did not undergo surveillance. A total of 22,462 person-years of observation were accrued (mean, 14 years per patient). Results The incidence of subsequent rectal cancer in these patients was similar to that in the general population (standardized incidence ratio, 1.2; 95 percent confidence interval, 0.7 to 2.1). Most rectal cancers developed in patients whose adenomas had been inadequately removed; the risk was very low after complete removal. The risk of subsequent colon cancer depended on the histologic type, size, and number of adenomas in the rectosigmoid. Among 842 patients with a rectosigmoid adenoma that was tubulovillous, villous, or large (≥1 cm), colon cancer developed...
1,018 citations
TL;DR: 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.
Abstract: 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 if 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, 141...
933 citations