Detection of Polyps After Resection of Colorectal Cancer

Bile acids as carcinogens in the colon and at other sites in the gastrointestinal system

Colon cancer incidence is associated with a high-fat diet. Such a diet is linked to elevated levels of bile acids in the gastrointestinal system and the circulation. Secondary bile acids are produced by microorganisms present at high concentrations in the colon. Recent prospective studies and a retrospective study in humans associate high circulating blood levels of secondary bile acids with increased risk of colon cancer. Feeding mice a diet containing a secondary bile acid, so their feces have the bile acid at a level comparable to that in the feces of humans on a high-fat diet, also causes colon cancer in the mice. Studies using human cells grown in culture illuminate some mechanisms by which bile acids cause cancer. In human cells, bile acids cause oxidative stress leading to oxidative DNA damage. Increased DNA damage increases the occurrence of mutations and epimutations, some of which provide a cellular growth advantage such as apoptosis resistance. Cells with such mutations/epimutations increase by natural selection. Apoptosis, or programmed cell death, is a beneficial process that eliminates cells with unrepaired DNA damage, whereas apoptosis-resistant cells are able to survive DNA damage using inaccurate repair processes. This results in apoptosis-resistant cells having more frequent mutations/epimutations, some of which are carcinogenic. The experiments on cultured human cells have provided a basis for understanding at the molecular level the human studies that recently reported an association of bile acids with colon cancer, and the mouse studies showing directly that bile acids cause colon cancer. Similar, but more limited, findings of an association of dietary bile acids with other cancers of the gastrointestinal system suggest that understanding the role of bile acids in colon carcinogenesis may contribute to understanding carcinogenesis in other organs.

Current status of water-assisted colonoscopy

Compared with the traditional air insufflation method, water-assisted colonoscopy has many advantages in clinical application with regard to reduced abdominal pain, increased cecal intubation rate, increased detection rate of colon adenoma, and increased complete resection rate of larger polyps. It has gradually attracted more and more attention both in China and other countries. The aim of this article is to elaborate the invention, development, and therapeutic applications of water-assisted colonoscopy, as well as its advantages and shortcomings.

Efficacy of three intestinal preparation methods for colonoscopy

AIM

To compare the advantages and disadvantages of three intestinal preparation methods for colonoscopy to identify the safest, simplest and fastest intestinal preparation method.

METHODS

A total of 105 patients undergoing colonoscopy at Department of Anorectal Surgery, Yuyao People's Hospita between August 2017 and January 2018 were randomly divided into groups A, B and C, which were orally administrated with sodium phosphate, compound polyethylene glycol electrolytes powder, and compound polyethylene glycol electrolytes powder + magnesium sulphate, respectively. Adverse reactions of the three intestinal cleansers were evaluated using questionnaires. Intestinal cleansing effect and intestinal bubble volume were evaluated by endoscopic surgeons.

RESULTS

Intestinal cleansing effect in groups A and C was superior to that of group B (P < 0.05). Adverse reactions in the group A were obviously less than those in group C (P < 0.05), although there was no statistically significant difference between group A and group B or between group B and group C (P > 0.05). Intestinal bubble volume presented no statistically significant difference among groups A, B and C (P > 0.05).

CONCLUSION

Intestinal cleansing effect of sodium phosphate and compound polyethylene glycol electrolytes powder + magnesium sulphate is superior to compound polyethylene glycol electrolytes powder. Moreover, sodium phosphate is characterized by low dose and mild intestinal adverse reactions; therefore, it should be the first choice in clinical practice.

Resting heart rate is an independent predictor of advanced colorectal adenoma recurrence

Background and aim

High heart rate is an independent predictor of total cancer incidence and all-cause mortality in patients with cancer. We aimed to evaluate the impact of resting heart rate on the recurrence of colorectal polyp, using long-term surveillance follow-up data of colorectal cancer survivors.

Methods

Three hundred patients were selected from the colorectal cancer survivor cohort of Severance Hospital, Seoul, Korea. Resting heart rate, physical activity, and body composition analysis at the time of 5-year survival, and clinical data including colonoscopy surveillance results were collected for mean follow-up duration of 8 years.

Results

Patients with a high resting heart rate showed a significantly higher recurrence rate of advanced adenoma than those with a low resting heart rate (quartile 1, 45–66 beats per minute (b.p.m.); quartile 2, 67–73 b.p.m.; quartile 3, 74–80 b.p.m.; quartile 4, 81–120 b.p.m.; 3.8% vs. 7.9% vs. 10.0% vs. 14.7%, p for trend = 0.018). After adjustment for various risk factors, patients in the highest quartile of resting heart rate (≥ 81 b.p.m.) had a significantly higher risk of advanced adenoma recurrence (hazard ratio [HR]: 6.183, 95% confidence interval [CI]: 1.181–32.373, p = 0.031), compared to those in the lowest quartile (≤ 66 b.p.m.). In subgroup analysis, the association of resting heart rate with advanced adenoma recurrence appeared to be stronger among patients who had more than normal body fat mass or sedentary life style.

Conclusions

Elevated resting heart rate was independently associated with a higher rate of advanced adenoma recurrence in colorectal cancer survivors.

The Effects of Physical Activity and Body Fat Mass on Colorectal Polyp Recurrence in Patients with Previous Colorectal Cancer

We aimed to identify the effects of physical activity and body composition on colorectal polyp recurrence in patients with previous colorectal cancer. A total of 300 patients were selected randomly from the colorectal cancer survivor cohort of Severance Hospital (Seoul, Korea). Patients reported various recreational physical activities and received surveillance colonoscopy. Body composition was measured with a body composition analyzer. We compared patients who exercised for at least 1 hour/week (active) with those who exercised less frequently or not at all (sedentary). The active exercise group (n = 203) had a lower recurrence of advanced adenoma than the sedentary group (n = 97; 6.4% vs. 14.4%, P = 0.023). The prevalence of advanced adenoma recurrence decreased in an exercise dose-dependent manner (P_trend = 0.019). In multivariate logistic analysis, the independent factors associated with advanced polyp recurrence were body fat mass [OR, 7.601; 95% confidence interval (CI), 1.583-36.485; P = 0.011] and active exercise (OR, 0.340; 95% CI, 0.143-0.809; P = 0.015). In Cox proportional hazards models, body fat mass (HR, 5.315; 95% CI, 1.173-24.083; P = 0.030) and active exercise (HR, 0.367; 95% CI, 0.162-0.833; P = 0.017) were the independent factors associated with cumulative advanced adenoma recurrence. In conclusion, exercising for at least 1 hour/week and low body fat mass were found to be related to lower rates of colorectal polyp recurrence in the surveillance of colorectal cancer survivors. Cancer Prev Res; 10(8); 478-84. ©2017 AACR.

Frequency of colonic adenomatous polyps in a tertiary hospital in Mumbai

INTRODUCTION

Incidence of colorectal carcinoma is increasing all over world. There is limited data on colorectal polyps from India. We evaluated the histomorphological features of colorectal polyps and determined risk stratification in adenomatous polyps.

METHODS

In 4970 consecutive colonoscopies, colorectal polyps were detected in 515 cases (10.3 %). Polyps were classified using standard histological criteria. Each polyp was evaluated for presence of dysplasia. Adenomatous polyps were classified as low-risk adenomas (1-2 tubular adenomas <10 mm) and high-risk adenomas characterized by villous histology, high-grade dysplasia, size ≥10 mm, or ≥3 adenomas.

RESULTS

Of 515 colorectal polyps, 270 (52.4 %) were adenomatous, followed by 78 (15.1 %) inflammatory, 78 (15.1 %) hyperplastic, 32 (6.2 %) hamartomatous polyps, 25 (4.8 %) benign epithelial polyps, 5 (0.9 %) cap polyps, 5 (0.9 %) lipomatous polyps, 3 (0.5 %) angiomatous polyps, 4 (0.7 %) lymphoid, and 15 (2.9 %) cases with adenocarcinoma masquerading as polyps. Mean (SD) age with colorectal polyps was 54.8 (33.0) years while for adenomatous polyps, 59.5 (14.8) years with male to female ratio of 2:1. Majority of adenomatous polyps 124 (45.9 %) were tubular adenomas present in rectosigmoid. High-grade dysplasia was found in 38 (14 %) adenomas. One hundred and fifty-five (57.4 %) were high risk of which majority were villous adenomas and nine (7.2 %) tubular adenomas.

CONCLUSION

The most common colorectal polyps found during routine colonoscopy were 270 adenomatous (52.4 %) cases. Of these, 155 (57.4 %) adenomatous polyps were high-risk category. Population prevalence data of colonic polyps in general population beyond the age of 50 years needs to be obtained.