Metachronous Colorectal Adenomas Research Articles

Metachronous Colorectal Adenomas Occur Close to the Index Lesion.

The aim of this study is to assess the spatial relationship between index and metachronous colorectal adenoma location. After the complete excision of a human sporadic colorectal adenoma, patients are at elevated risk of developing a further metachronous adenoma. Data regarding the occurrence site of a metachronous colorectal adenoma relative to the index adenoma are scarce. Prospectively maintained databases were interrogated to identify all colonoscopies and adenoma excisions performed over a 10-year period at a single university teaching hospital. Data for the colonic segments at which adenoma removal were reported at index and all subsequent colonoscopies were extracted and 2 allied data sets merged. A total of 15,121 colonoscopies and 4759 polyp events were recorded. Four hundred fifty-two patients [296 male, 156 female, median (range) age 75 (32 to 100) y] developed at least 1 metachronous adenoma at follow-up colonoscopy. When single index events only are considered (ie, synchronous adenoma cases excluded), over 61% of metachronous adenomas were recorded in the same or an adjacent colonic segment. When the full span of the colon is considered, metachronous adenomas were more likely to occur in a section of the colon proximal to that of the index adenoma (41%±5%) than the same (39%±5%) or distal segment (20%±5%; P=0.006; 1-way χ2 test). A metachronous human sporadic colorectal adenoma is more likely to be found in the same colonic segment to that of the index adenoma or 1 immediately adjacent. These data suggest a shared origin of metachronous adenoma with preceding lesions, supporting the existence of precancerous fields.

Genome-Wide Association Study of Metachronous Colorectal Adenoma Risk among Participants in the Selenium Trial

Genetic variants related to colorectal adenoma may help identify those who are at highest risk of colorectal cancer development or illuminate potential chemopreventive strategies. The purpose of this genome-wide association study was to identify genetic variants that are associated with risk of developing a metachronous colorectal adenoma among 1,215 study participants of European descent from the Selenium Trial. Associations of variants were assessed with logistic regression analyses and validated in an independent case-control study population of 1,491 participants from the Colorectal Cancer Study of Austria (CORSA). No statistically significant genome-wide associations between any variant and metachronous adenoma were identified after correction for multiple comparisons. However, an intron variant of FAT3 gene, rs61901554, showed a suggestive association (P = 1.10 × 10−6) and was associated with advanced adenomas in CORSA (P = 0.04). Two intronic variants, rs12728998 and rs6699944 in NLRP3 were also observed to have suggestive associations with metachronous lesions (P = 2.00 × 10−6) in the Selenium Trial and were associated with advanced adenoma in CORSA (P = 0.03). Our results provide new areas of investigation for the genetic basis of the development of metachronous colorectal adenoma and support a role for FAT3 involvement in the Wnt/β-catenin pathway leading to colorectal neoplasia. Trial Registration number: NCT00078897 (ClinicalTrials.gov).

Effect Modification of Selenium Supplementation by Intake and Serum Concentrations of Antioxidants on the Development of Metachronous Colorectal Adenoma

BackgroundSelenium (Se) is a trace element that has been investigated as a potential chemopreventive agent for colorectal cancer. Dietary intake of other antioxidant nutrients may modify the effect of Se.ObjectiveWe examined the association between intake and serum concentrations of retinol, β-carotene, β-cryptoxanthin, lycopene, lutein/zeaxanthin, and α- and γ-tocopherol and the development of metachronous colorectal adenoma, and if these nutrients modified the effect of Se.MethodsWe conducted a prospective study of 1874 participants from the Se Trial with data for antioxidant intake, as well as a subcohort of 508 participants with serum biomarker concentrations.ResultsStatistically significantly lower odds for the development of metachronous adenoma were observed for those participants in the highest tertile of intake for lutein/zeaxanthin compared to the lowest, with an OR (95% CI) of 0.72 (0.56-0.94). No effect modification for intake of any nutrient was observed. However, circulating concentrations of lycopene exhibited statistically significant effect modification of selenium supplementation (p < 0.06),ConclusionThese findings show that intake and circulating concentrations of antioxidant nutrients were not consistently associated with reduced odds for the development of metachronous lesions, although blood concentrations of lycopene may modify the effect of selenium supplementation.

Oral Antibiotics and Risk of New Colorectal Adenomas During Surveillance Follow-up.

Antibiotics may increase colorectal neoplasia risk by modifying the gut microbiome. It is unknown whether use is associated with the risk of new colorectal adenomas among individuals with prior adenomas. We performed a secondary analysis of four randomized clinical trials for the chemoprevention of colorectal adenomas. Participants self-reported all currently used prescription drugs shortly after an initial colorectal adenoma diagnosis and two or three times a year thereafter over 3 to 5 years of follow-up. We estimated adjusted risk ratios (RR) with 95% confidence intervals (CI) for incident adenomas, analyzing the four trials together. Cumulatively, the four trials enrolled 5,174 participants (3,491 men and 1,683 women), of whom 4,769 (92%) completed ≥1 follow-up colonoscopy. A total of 763 (15%) participants reported using oral antibiotics on ≥2 occasions. Overall, 39% of those using oral antibiotics at least twice developed new colorectal adenomas compared with 40% of those with no use or a single report of use (RR, 0.99; 95% CI, 0.90-1.10). No statistically significant associations were found in study-specific analyses, and results were similar for high- and low-risk adenoma findings, antibiotic class, anatomic location of adenomas, and analyses excluding those with interim colorectal exams. Oral antibiotic use during colonoscopic surveillance after an initial adenoma diagnosis was not associated with risk of these polyps. Any changes to the gut microbiome as a consequence of oral antibiotic use during surveillance may not affect the development of metachronous colorectal adenomas.

Fecal Fusobacterium nucleatum as a predictor for metachronous colorectal adenoma after endoscopic polypectomy.

Fusobacterium nucleatum is increasingly being recognized as an important risk factor in colorectal cancer and colorectal adenoma. Endoscopic polypectomy is associated with a decreased incidence of colorectal cancer; however, patients still suffer from a risk of metachronous adenoma. Currently, there are few effective non-invasive factors that may predict metachronous colorectal adenoma. Here, we evaluated the performance of F.nucleatum in predicting metachronous adenoma. Fecal samples and clinical information of patients before endoscopic polypectomy were collected from 367 patients in a retrospective cohort, and 238 patients in a prospective cohort. The abundance of fecal F.nucleatum was measured via quantitative polymerase chain reaction. Surveillance colonoscopies were conducted between 1 and 3years after polypectomy (average follow-up 27.07months for the retrospective cohort & 22.57months for the prospective cohort) to identify metachronous adenoma. Candidate predictive factors and cut-off value of F.nucleatum abundance were identified from the retrospective cohort and then validated in the prospective cohort. A high abundance of fecal F.nucleatum was found to be an independent risk factor for metachronous adenomas (odds ratio, 6.38; P<0.001) in the retrospective cohort and was validated in the prospective cohort with a specificity of 65.00%, and a sensitivity of 73.04%, and an overall performance with the area under the curve of 0.73. Fecal abundance of F.nucleatum may be a reliable predictor for metachronous adenoma after endoscopic polypectomy.

Characteristics and risk factors for early-onset metachronous colorectal adenoma

Characteristics and risk factors for early-onset metachronous colorectal adenoma

Circulating Fibroblast Growth Factor-21 and Risk of Metachronous Colorectal Adenoma.

Prior work has shown that higher circulating concentrations of fibroblast growth factor-21 (FGF-21) are associated with an increased likelihood of developing colorectal cancer. We conducted a prospective study to assess the relationship between circulating FGF-21 and odds of developing early neoplastic lesions in the colorectum. A total of 94 study participants were included from the ursodeoxycholic acid (UDCA) trial, a phase III, randomized, double-blind, placebo-controlled clinical trial of the effect of 8-10mg/kg of body weight UDCA vs. placebo. Logistic regression analyses were conducted to evaluate the association between baseline FGF-21 concentrations and odds of developing a metachronous adenoma. Of the characteristics compared across tertiles of FGF-21 concentrations, including age, race, sex, BMI, and other variables, only a previous personal history of colorectal polyps prior to entry into the UDCA trial was statistically significantly related to FGF-21 levels, with a proportion of 26.7%, 56.7%, and 50.0% across the first, second, and third tertiles, respectively (p < 0.05). Higher circulating concentrations of FGF-21 were statistically significantly associated with greater odds of developing a metachronous colorectal adenoma. After adjusting for potential confounders and when compared with the lowest tertile of FGF-21, the adjusted ORs (95% CIs) for metachronous colorectal adenoma in the second and third tertiles were 4.72 (95% CI, 1.42-15.72) and 3.82 (95% CI, 1.15-12.68), respectively (p trend < 0.05). Our results reveal for the first time that, in addition to a recently discovered association with colorectal cancer, circulating FGF-21 concentrations are significantly and directly associated with odds of developing metachronous colorectal adenoma.

Abstract 1143: Circulating 27-hydroxycholesterol and risk of metachronous colorectal adenomas

Abstract Purpose: Oxysterols are cholesterol metabolites thought to play a role in basic carcinogenic mechanisms. One of the most abundant oxysterols in circulation is 27-hydroxycholesterol (27HC), which has been shown to be an endogenous selective estrogen receptor modulator and implicated in breast cancer etiology. 27HC is a ligand for liver X receptors expressed in the liver, gut, adipose tissue, and macrophages. In the colorectum, expression of these receptors suppresses cellular proliferation. It is unknown whether circulating 27HC is associated with the risk of developing colorectal neoplasia. Methods: Circulating 27HC was measured in plasma collected at baseline from participants of the Vitamin D/Calcium Polyp Prevention Study, a completed placebo-controlled randomized clinical trial of daily supplementation with vitamin D, calcium, or both for the prevention of colorectal adenomas. Participants were 2,259 men and women, 45-75 years old, diagnosed with ≥1 colorectal adenoma within 120 days prior to enrollment. Each was followed for new colorectal adenomas during a 3- or 5-year colonoscopy surveillance interval. 27HC concentrations were quantified using high-performance liquid chromatography/mass spectrometry for those who reported fasting ≥8 hours at the time of blood draw. Premenopausal women and postmenopausal women currently using hormone therapy were excluded from analyses. Risk ratios (RR) and 95% confidence intervals (CI) were estimated from log-linear regression models with adjustment for sex, age, race/ethnicity, body mass index, smoking status, family history of colorectal cancer, aspirin use, nonsteroidal anti-inflammatory drug use, and former use of postmenopausal hormone therapy. High-risk colorectal adenoma findings were defined as ≥1 advanced adenoma (≥1 cm in diameter, with 25% villous components, high-grade dysplasia, or adenocarcinoma) or ≥3 synchronous adenomas of any type. Secondary analyses considered results stratified by sex and anatomic location of lesions (proximal colon vs. distal colon/rectum). Results: In total, 27HC was measured for 1,246 participants (894 men and 352 women). Circulating 27HC was higher among men (mean, 181 ng/mL; standard deviation, SD, 49 ng/mL) than among postmenopausal women (mean, 154 ng/mL; SD, 46 ng/mL). During follow-up, 596 (46%) participants were diagnosed with ≥1 new colorectal adenoma. Circulating 27HC was associated with 9% higher risk of any colorectal adenoma per SD increase (RR, 1.09; 95% CI, 1.02-1.15; P=0.008) and 19% higher risk of high-risk colorectal adenoma findings per SD increase (RR, 1.19; 95% CI, 1.07-1.33; P=0.002). Sex-stratified results were of similar magnitude, and there were no meaningful differences according to anatomic location of adenomas. Conclusions: Circulating 27HC concentration may be a novel risk factor for metachronous colorectal adenomas. Citation Format: Michael N. Passarelli, Bonne M. Thompson, Jeffrey G. McDonald, Thomas J. Palys, Judy R. Rees, Elizabeth L. Barry, John A. Baron. Circulating 27-hydroxycholesterol and risk of metachronous colorectal adenomas [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1143.

Green tea extract to prevent colorectal adenomas in men and women: Results of the MIRACLE trial.

1551 Background: Prevention of colorectal adenomas (CA) can reduce colorectal cancers (CRC). Epidemiological and experimental data suggest that the green tea catechin epigallocatechingallate has an antineoplastic effect in the large bowel. MIRACLE is the largest trial so far to examine the effect of three-year daily intake of green tea extract (GTE) on the incidence of metachronous CA in a Caucasian population. Methods: Prospective, parallel group, double-blinded, placebo-controlled, randomized multicenter trial (40 German centers, recruitment 11/2011-6/2015). Patients (n = 1001, age 50-80y), polypectomy ≤ 6 months and tolerating GTE well (one-month run-in) were randomized to receive decaffeinated GTE standardized to EGCG (150 mg bid, capsules) or placebo (P) for 3 years. Primary endpoint: Incidence of metachronous CA at the 3-year follow-up colonoscopy. Secondary endpoints: Occurrence, number, localization, size, histological subtype of CA, frequency of CRC, biomarker and safety. Strata: study center, low-dose aspirin (≤100 mg/d). Results: Clinical parameters were well balanced. CA incidence at the 3-year follow-up colonoscopy was analyzed in the modified ITT set (modITT; n = 309 patients (GTE), n = 323 (placebo), timely follow up colonoscopy) and the per protocol set (PP, modITT set without major protocol violations). Incidence of CA was 55.7 % (P) and 51.1% (GTE), (modITT, adj. RR 0.905, one sided, p = 0.081), respectively 54.3 % (P) and 48.3% (GTE) (PP, adj. RR 0.883, one sided, p = 0.058). These differences did not reach statistical significance. In the preplanned exploratory analysis regarding gender incidence of CA in females was 47.9% (P) and 47.6% (GTE) in the modITT-set (adj. RR 0.989; 95%-CI: 0.753,1.299; p = 0.935), respectively 45.4% (P) and 46.9% (GTE) in the PP-set (adj. RR 1.014; 95%-CI: 0.748, 1.373; p = 0.930). In contrast, in the male population incidence of CA in the follow-up colonoscopy was 60.4% (P) and 52.9% (GTE) in the modITT-set (adj. RR 0.846; 95% CI 0.717, 0.999); p = 0.048), respectively 59.1% (P) and 49.1% (GTE) in the PP-set (RR 0.803, 95% CI: 0.666, 0.969; p = 0.022). Thus, GTE intake was associated with a significant, 12.4 relative and 7.5% absolute reduction of metachronous CA in the male modITT population. There were no differences with respect to safety between the groups. Conclusions: GTE reduced the incidence of metachronous CA. However, a significant effect was only observed in the in the male population whereas there was no effect in the female population. Clinical trial information: NCT 01360320.

Body Composition and Aspirin Dose for Colorectal Adenoma Prevention in a Randomized Clinical Trial.

Visceral adiposity is a risk factor for colorectal adenomas, and aspirin is an established chemopreventive agent. Evidence from clinical trials suggests the effectiveness of aspirin at preventing cardiovascular disease and cancer may require higher doses for higher body weight. Body mass index, body surface area, fat-free mass, and fat mass were calculated from baseline height and weight in 1,121 participants of the Aspirin/Folate Polyp Prevention Study, a double-blind, placebo-controlled, 3 × 2 factorial randomized clinical trial of low-dose (81 mg/day) or high-dose (325 mg/day) aspirin and/or 1 mg/day folic acid to prevent metachronous colorectal adenomas. Participants were treated during a surveillance colonoscopy interval of approximately 3 years. Risk ratios (RR) with 95% confidence intervals (CI) for any colorectal neoplasia and high-risk adenoma (HRA, advanced or ≥3 adenomas) were estimated from log-linear regression. We did not find evidence to suggest aspirin dose-response differed by body composition measurements, including weight alone. Among those weighing ≥ 80 kg, treatment effects for low-dose aspirin (RR for colorectal neoplasia, 0.75; 95% CI, 0.60-0.94; RR for HRA, 0.52; 95% CI, 0.31-0.86) and high-dose aspirin (RR for colorectal neoplasia, 0.88; 95% CI, 0.72-1.08; RR for HRA, 0.68; 95% CI, 0.43-1.09) were not meaningfully different than for those weighing 70-79 kg or <70 kg. Measurements of body composition calculated from height and weight did not modify aspirin treatment effects for colorectal adenoma prevention. Aspirin dosing strategies accounting for body weight suggested in previous trials of colorectal cancer may not apply to adenomas.

Does Colonic Diverticulosis Raise the Risk of Colorectal Adenoma in Patients with Colorectal Cancer?

Background The aim of this study was to evaluate the risk of development of colorectal adenomas in patients with colorectal cancer (CRC) with and without colonic diverticulosis. Methods We performed a retrospective cohort study that included patients with CRC between 2008 and 2011. All patients underwent preoperative colonoscopic and barium enema examinations. Follow-up colonoscopic examinations were performed within 1 year and between 3 and 5 years postoperatively. The incidence of colorectal adenomas was compared based on the presence or absence of diverticulosis. Additionally, multivariate logistic regression analysis was performed to identify the factors independently associated with the development of synchronous and metachronous colorectal adenomas. Results Of the 168 patients with CRC included in the study, 55 showed colonic diverticulosis. Synchronous colorectal adenomas were more common in CRC patients with diverticulosis than in those without diverticulosis (P > 0.001). Multivariate regression analysis showed that colonic diverticulosis (odds ratio (OR) 3.874, 95% confidence interval (CI) 1.843–8.144, P > 0.001) and obesity (body mass index > 25.0 kg/m2, OR 2.395, 95% CI 1.089–5.270, P = 0.030) were associated with an increased risk of synchronous colorectal adenomas. The presence of synchronous colorectal adenomas increased the risk of metachronous colorectal adenomas (OR 4.407, 95% CI 1.855–10.473, P > 0.001). Conclusions Colonic diverticulosis was associated with synchronous colorectal adenomas in patients with CRC, which is eventually increasing the risk of metachronous adenomas.

A Comparison of the Cumulative Incidences of Metachronous Colorectal Adenoma and Cancer According to the Initial FindingsAmong Colonoscopically Followed-up Patients

A Comparison of the Cumulative Incidences of Metachronous Colorectal Adenoma and Cancer According to the Initial FindingsAmong Colonoscopically Followed-up Patients

Prevalence and risk factors for colorectal adenomas in patients with ulcerative colitis.

Patients with ulcerative colitis (UC) have an increased risk of colorectal cancer. Scarce data regarding the development of adenomas in these patients are available both for normal and colitic mucosa. The objective of this article is to evaluate the prevalence of adenomatous polyps and associated risk factors in patients with UC. Patients with UC were identified from the databases of two tertiary referral centers. Medical, endoscopic and histologic reports were reviewed. A total of 403 patients were included (53% male; 33% extensive colitis) and 1065 colonoscopies (median per patient, 2) were recorded and analyzed. Seventy-four adenomas in 47 patients (11.7%) and three cases of colorectal cancer were found during a median follow-up of 6.3 years. The cumulative risk of colorectal adenoma was 4.7%, 16.7%, 23.6% and 34.4% at 10, 20, 30 and 40 years from UC diagnosis, respectively. The cumulative risk of developing metachronous colorectal adenoma was 66.7%, 87.9%, and 90.9% at 5, 10, and 15 years from first adenoma detection. Older age at UC diagnosis and longer disease duration were independent risk factors for colorectal adenoma development. The prevalence of colorectal adenomas among UC patients seems to be higher than previously reported, although lower than in the background population.

Family history of colorectal cancer in first-degree relatives and metachronous colorectal adenoma.

Little is known about the relationship between having a first-degree relative (FDR) with colorectal cancer (CRC) and risk for metachronous colorectal adenoma (CRA) following polypectomy. We pooled data from seven prospective studies of 7697 patients with previously resected CRAs to quantify the relationship between having a FDR with CRC and risk for metachronous adenoma. Compared with having no family history of CRC, a positive family history in any FDR was significantly associated with increased odds of developing any metachronous CRA (OR = 1.14; 95% CI = 1.01-1.29). Higher odds of CRA were observed among individuals with an affected mother (OR = 1.27; 95% CI = 1.05-1.53) or sibling (OR = 1.34; 95% CI = 1.11-1.62) as compared with those without, whereas no association was shown for individuals with an affected father. Odds of having a metachronous CRA increased with number of affected FDRs, with ORs (95% CIs) of 1.07 (0.93-1.23) for one relative and 1.39 (1.02-1.91) for two or more. Younger age of diagnosis of a sibling was associated with higher odds of metachronous CRA, with ORs (95% CIs) of 1.66 (1.08-2.56) for diagnosis at <54 years; 1.34 (0.89-2.03) for 55-64 years; and 1.10 (0.70-1.72) for >65 years (p-trend = 0.008). Although limited by sample size, results for advanced metachronous CRA were similar to those for any metachronous CRA. A family history of CRC is related to a modestly increased odds of metachronous CRA. Future research should explore whether having a FDR with CRC, particularly at a young age, should have a role in risk stratification for surveillance colonoscopy.

Left-Sided Colectomy: One of the Important Risk Factors of Metachronous Colorectal Adenoma After Colectomy for Colon Cancer.

Patients with a history of colonic resection for cancer have an increased risk for the development of metachronous malignant lesions. However, there is a lack of data on the detection rates of premalignant lesions during colonoscopy surveillance in these patients, and the few existing studies have shown conflicting results. To identify the risk factor of metachronous premalignant lesions after colon cancer surgery. We retrospectively screened consecutive patients who had undergone colonic surgery to treat colon cancer at the Chungnam National University Hospital between September 2009 and April 2014. We measured polyp, adenoma, and advanced adenoma detection rates (PDR, ADR, AADR) from the second surveillance colonoscopy in patients with left-sided colectomy (LCR) or right-sided colectomy (RCR). Multivariate analysis was performed to adjust for other confounding factors. A total of 348 patients were enrolled (220 LCR patients and 128 RCR patients). The PDR, ADR, and AADR in patients in the LCR and RCR groups were 56.4, 43.6, and 11.8% and 35.9, 26.6, and 9.4%, respectively. PDR and ADR in the LCR group were significantly higher than those in the RCR group. A multivariate analysis showed that male sex, hypertension, body mass index higher than 25, and LCR (odds ratio 2.090; 95% confidence interval 1.011-4.317) were associated with adenoma recurrence. The LCR group had a higher adenoma recurrence rate than the RCR group. Further studies are required to determine the optimal surveillance intervals according to the type of colonic resection.

Obesity-related parameters and colorectal adenoma development.

Obesity increases the risk of colorectal adenoma and colorectal cancer. However, the obesity-related parameters that are best for assessing the risk of colorectal adenoma development remain unclear. We analyzed the parameters that may best describe the association between obesity and colorectal adenoma development. In this retrospective cohort study, 3405 individuals underwent screening colonoscopy during routine health examinations. We measured body mass index; waist circumference; and metabolic parameters such as high-density lipoprotein-cholesterol, glucose, triglyceride, and systolic blood pressure. We analyzed the risk of developing colorectal adenoma, relative to obesity-related parameters, over a mean interval of 5.8years from baseline colonoscopy. In a multivariate analysis, waist circumference was the only obesity-related marker associated with an increased risk of metachronous colorectal adenoma. Men with waist circumferences ≥85cm and women with waist circumference ≥82cm had a 31% increased risk of metachronous colorectal adenoma compared to those with smaller waist circumferences [odds ratio (OR) 1.31; 95% confidence interval (CI, 1.09-1.57)]. Other factors associated with metachronous colorectal adenoma were age (OR, 1.03; 95% CI 1.02-1.04), male sex (OR 1.49; 95% CI 1.17-1.88), alcohol consumption ≥3/week (OR 1.33; 95% CI 1.10-1.62), the number of adenoma at baseline (OR 1.21; 95% CI 1.10-1.33), and the presence of advanced adenoma at baseline (OR 1.60; 95% CI 1.24-2.06). Our findings suggest that central obesity, represented by waist circumference, is a significant predictor of metachronous colorectal adenoma, independent of body mass index and other metabolic variables.

Green tea extracts for the prevention of metachronous colorectal polyps among patients who underwent endoscopic removal of colorectal adenomas: A randomized clinical trial

To determine the preventive effect of green tea extract (GTE) supplements on metachronous colorectal adenoma and cancer in the Korean population. One hundred seventy-six subjects (88 per each group) who had undergone complete removal of colorectal adenomas by endoscopic polypectomy were enrolled. They were randomized into 2 groups: supplementation group (0.9g GTE per day for 12 months) or control group without GTE supplementation. The 72-h recall method was used to collect data on food items consumed by participants at baseline and the 1-year follow-up during the past 48h. Follow-up colonoscopy was conducted 12 months later in 143 patients (71 in control group and 72 in the GTE group). Of the 143 patients completed in the study, the incidences of metachronous adenomas at the end-point colonoscopy were 42.3% (30 of 71) in control group and 23.6% (17 of 72) in GTE group (relative risk [RR], 0.56; 95% confidence interval [CI], 0.34-0.92). The number of relapsed adenoma was also decreased in the GTE group than in the control group (0.7±1.1 vs. 0.3±0.6, p=0.010). However, there were no significant differences between the 2 groups in terms of body mass index, dietary intakes, serum lipid profiles, fasting serum glucose, and serum C-reactive protein levels (all p>0.05). This study of GTE supplement suggests a favorable outcome for the chemoprevention of metachronous colorectal adenomas in Korean patients(ClinicalTrials.gov number, NCT02321969).

Colorectal Cancer Prevention.

Colorectal Cancer Prevention.

NSAIDs and EGFR Inhibitors for Duodenal Polyp Prevention.

Familialadenomatouspolyposis (FAP)andattenuatedFAP(AFAP) are relatedgeneticconditions thatarecharacterizedbymultiple synchronous and metachronous colorectal adenomas with a 70% to 100%riskofdevelopingcolorectal cancer (CRC)and, lessoften,duodenal neoplasia. Although both of these conditions are caused by mutations in the coding region of the adenomatous polyposis coli (APC) tumor suppressor gene, thephenotypespresentquitedistinctly in correlationwith the position of the mutation within the coding region. In classic FAP, which presents with amuch greater polyp burden at an earlier age and a greater risk of CRC than AFAP, the mutation occurs in the central region of the protein, whereas mutations in the Nor CterminusareassociatedwithAFAP.TheAmericanGastroenterological Association recommends an annual sigmoidoscopy, beginning at ages 10 to 12 years, for patients with a genetic diagnosis of FAP, or at-risk familymemberswhohavenotundergonegenetic testing.1 Genetic and endoscopic screening of patients and family members, followed by timely treatment, has led to a 55% reduction in the occurrence of CRC at diagnosis of FAP, and improved cumulative survival amongall FAPpatients. In fact, duodenal cancer is now amore common cause of death than CRC in this population. TreatJAMA

Risk factors for metachronous colorectal cancer following a primary colorectal cancer: A prospective cohort study.

Individuals diagnosed with colorectal cancer (CRC) are at risk of developing a metachronous CRC. We examined the associations between personal, tumour-related and lifestyle risk factors, and risk of metachronous CRC. A total of 7,863 participants with incident colon or rectal cancer who were recruited in the USA, Canada and Australia to the Colon Cancer Family Registry during 1997-2012, except those identified as high-risk, for example, Lynch syndrome, were followed up approximately every 5 years. We estimated the risk of metachronous CRC, defined as the first new primary CRC following an interval of at least one year after the initial CRC diagnosis. Observation time started at the age at diagnosis of the initial CRC and ended at the age at diagnosis of the metachronous CRC, last contact or death whichever occurred earliest, or were censored at the age at diagnosis of any metachronous colorectal adenoma. Cox regression was used to derive hazard ratios (HRs) and 95% confidence intervals (CIs). During a mean follow-up of 6.6 years, 142 (1.81%) metachronous CRCs were diagnosed (mean age at diagnosis 59.8; incidence 2.7/1,000 person-years). An increased risk of metachronous CRC was associated with the presence of a synchronous CRC (HR = 2.73; 95% CI: 1.30-5.72) and the location of cancer in the proximal colon at initial diagnosis (compared with distal colon or rectum, HR = 4.16; 95% CI: 2.80-6.18). The presence of a synchronous CRC and the location of the initial CRC might be useful for deciding the intensity of surveillance colonoscopy for individuals diagnosed with CRC.