In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 36, No. 4_suppl ( 2018-02-01), p. 555-555
Abstract:
555 Background: The role of genetic profile of polyps to predict advanced metachronous lesions (AML) remains unknown. The aim is to study the relation between genetic profile of polyps and both risk of AMLs and time to develop them in surveillance. Methods: 308 patients with colonic polyps were consecutively enrolled between 2007 and 2009 for this cohort study, and followed up to 2014 (median 26 months, range 63). Variables as age, sex, smoking, weight, number of colonoscopies and number and characteristics of polyps were collected. 995 polyps were analyzed for somatic mutations on BRAF and KRAS genes using allelic discrimination by real-time PCR and direct DNA sequenciation, respectively. High level of methylation on CpG islands (CIMP-H) was also tested using MS-MLPA. AML was defined by a size higher than 9mm, high grade dysplasia or villous component. Risk of developing AML for individual genetic markers was studied using Chi-square tests and logistic regression. Log-rank test with Kaplan Meier survival curves and Cox-regression model were also performed. Multivariate analysis were adjusted by sex, age, familial colorectal cancer, smoking and features of AML in first colonoscopy. Results: 21% of polyps in first colonoscopy were CIMP-H. KRAS and BRAF mutations accounted for 25% and 17% of polyps, respectively. In univariate analysis, KRAS-mutated polyps were related to higher risk of AML in surveillance (52% KRAS-mutated polyps vs 31% non-mutated; p = 0.01). Similar results were obtained regarding CIMP-H (77% CIMP-H polyps vs 38% non-CIMP; p = 0.005). Logistic regression showed CIMP-H as the unique genetic marker of risk for AML (OR 11.41, 95% CI 2.04-63.70; p = 0.006). Regarding time to develop AML, shorter intervals were found related to CIMP-H (median of 31 vs 48 months in non-CIMP-H; p = 0.002) and KRAS-mutations (median of 36 vs 49 months in non-mutated; p = 0.029) in univariate analysis. Multivariate analysis highlighted CIMP-H as the unique independent marker associated to shorter time to develop AML (HR 4.01, 95% CI 1.36-10.46; p = 0.01). Conclusions: Presence of CIMP-H in polyps associates higher risk of subsequent AML and shorter interval to their development. Genetic profile of polyps emerges as useful tool for colonoscopy surveillance.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/JCO.2018.36.4_suppl.555
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2018
detail.hit.zdb_id:
2005181-5
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