Colorectal polyps: the scope and management of the problem.
ABSTRACT Colorectal cancer affects over 150,000 individuals yearly, and accounts for over 50,000 deaths. Much of the benefit of colorectal cancer screening has been attributed to detection and removal of adenomatous polyps, highlighting the importance of colorectal polyps as targets for intervention and as biomarkers for colorectal cancer risk. This review details the epidemiology of sporadic colorectal polyps, rationale behind use of polyps as an important surrogate for colorectal cancer risk, the benefits and limitations of secondary prevention of colorectal polyps through chemopreventive and dietary interventions, as well as colon surveillance.
BMJ (online) 10/2013; 347:f5843. DOI:10.1136/bmj.f5843 · 16.38 Impact Factor
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ABSTRACT: Adenocarcinoma represents 96-98% of colorectal neoplasms, and neoplastic polyps (adenomas) are their precursors. The aim of this study is to correlate size, location and histologic type of colorectal polyps at the presence of dysplasia and adenocarcinoma. Methods: Colonoscopies from January/2007 to December/2008 were retrospectively studied, in order to evaluate the characteristics of the polyps. Results and Discussion: Out of the 2,401 analyzed colonoscopies, 583 (24.3%) presented polyps. Due to the lack of histopathologic data, 139 exams were excluded. Mean age of the patients was 58±12 years, and 60% were females. Polyps were prevalent in the left colon (38.5%) and rectum (32.5%). Out of the 850 polyps which were histologically examined, 55.17% were tubular adenomas; 21.88%, hyperplastic; 17.05%, serrated; 5.4%, tubulovillous; and 0.47%, villous. As to polyps £1.0 cm, dysplasia was observed in 16.0% and adenocarcinoma in 1.9%. Those >1.0 cm, 72.0% (p<0.001) presented dysplasia, and 25.3% (p<0.001) presented adenocarcinoma. Polyps in the right and transverse colon were strongly associated with dysplasia (17.8% and 16.7%). Adenocarcinomas were prevalent in the left colon (2.5%) and rectum (2.1%). Conclusion: Polyps were more frequent in the left colon and rectum. The right and transverse colons were strongly correlated with dysplasia. Those of the left colon and rectum were associated with adenocarcinoma. Lesions >1.0 cm were positively related to dysplasia and neoplasm.09/2011; 31(3):241-247. DOI:10.1590/S2237-93632011000300003
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ABSTRACT: Risk stratification using number, size, and histology of colorectal adenomas is currently suboptimal for identifying patients at increased risk for future colorectal cancer (CRC). We hypothesized that molecular markers of carcinogenesis in adenomas, measured via immunohistochemistry, may help identify high-risk patients. To test this hypothesis, we conducted a retrospective, 1:1 matched case-control study (n=216; 46% female) in which cases were patients with CRC and synchronous adenoma and controls were patients with adenoma but no CRC at baseline or within 5 years of follow-up. In phase I of analyses, we compared expression of molecular markers of carcinogenesis in case and control adenomas, blind to case status. In phase II of analyses, patients were randomly divided into independent training and validation groups to develop a model for predicting case status. We found that seven markers (p53, p21, Cox-2, beta-catenin, DNA dependent protein kinase (DNApkcs), survivin, and 0(6)-methylguanine-DNA methyltransferase (MGMT)) were significantly associated with case status on unadjusted analyses, as well as analyses adjusted for age and advanced adenoma status (p<0.01 for at least one marker component). When applied to the validation set, a predictive model using these 7 markers showed substantial accuracy for identifying cases (AUC=0.83; 95% CI:0.74-0.92). A parsimonious model employing 3 markers performed similarly to the 7 marker model (AUC=0.84). In summary, we found that molecular markers of carcinogenesis distinguished adenomas from patients with and without CRC. Further, we speculate that prospective studies utilizing molecular markers to identify individuals with polyps at risk for future neoplasia are warranted.Cancer Prevention Research 08/2014; 7(10). DOI:10.1158/1940-6207.CAPR-14-0140 · 5.27 Impact Factor