Optimal Colonoscopy Surveillance Interval after Polypectomy

Risk factors for intraepithelial neoplasia in patients with colorectal adenoma

AIM

To identify risk factors for intraepithelial neoplasia in colorectal adenoma by analyzing the clinical, endoscopic, and histopathological features of patients with colorectal adenoma.

METHODS

The clinical, endoscopic, and histopathological features of 657 patients with colorectal adenomatous polyps diagnosed by colonoscopy from January 2014 to April 2016 at Wuhan Union Hospital were retrospectively analyzed. The patients were divided into an intraepithelial neoplasia group and a non-intraepithelial neoplasia group according to the pathological diagnosis. χ² test was applied for univariate analysis between the two groups. Multivariate Logistic regression analysis was used to identify the risk factors for intraepithelial neoplasia and its malignancy degree in adenoma.

RESULTS

Most of colorectal adenomas were located in the left colon. The total incidence of intraepithelial neoplasia in colorectal adenoma was 22.68%. Age, polyp diameter, length of pedicle, and pathologic type were identified to be risk factors for intraepithelial neoplasia in adenoma, which could be incorporated in Logistic regression equation: logit P = -4.384 + 0.796X2 (age) + 0.324X3 (polyp diameter) + 1.296X4 (pedicle condition) + 0.944X7 (pathology type). Gender, age, and polyp size were identified to be risk factors for high-grade intraepithelial neoplasia in adenoma, which could be incorporated in Logistic regression equation: logit P = -2.939 + 1.036X1 (gender) + 0.853X2 (age) + 1.023X3 (polyp diameter). Total cholesterol (TC) and triglyceride (TG) in the low-grade and high-grade intraepithelial neoplasia groups were both significantly higher than those in the non-intraepithelial neoplasia group (P < 0.05). Low-density lipoprotein cholesterol (LDL-C) and uric acid (URIC) in the high-grade intraepithelial neoplasia group were both significantly higher than those in the non-intraepithelial neoplasia group (P < 0.05). There was no significant difference in the high-density lipoprotein cholesterol (HDL-C) or CEA among the three groups.

CONCLUSION

There is a greater risk of intraepithelial neoplasia among patients older than 40, having villous adenoma with diameter > 1 cm and pedicle. Male, polyp diameter, and age are risk factors for high-grade intraepithelial neoplasia in colorectal adenoma. The occurrence of intraepithelial neoplasia in adenoma may be related to blood lipids and uric acid levels.

Three-year colonoscopy surveillance after polypectomy in Korea: a Korean Association for the Study of Intestinal Diseases (KASID) multicenter prospective study

Background/Aims

Colonoscopic surveillance is currently recommended after polypectomy owing to the risk of newly developed colonic neoplasia. However, few studies have investigated colonoscopy surveillance in Asia. This multicenter and prospective study was undertaken to assess the incidence of advanced adenoma based on baseline adenoma findings at 3 years after colonoscopic polypectomy.

Methods

A total of 1,323 patients undergoing colonoscopic polypectomy were prospectively assigned to 3-year colonoscopy surveillance at 11 tertiary endoscopic centers. Relative risks for advanced adenoma after 3 years were calculated according to baseline adenoma characteristics.

Results

Among 1,323 patients enrolled, 387 patients (29.3%) were followed up, and the mean follow-up interval was 31.0±9.8 months. The percentage of patients with advanced adenoma on baseline colonoscopy was higher in the surveillance group compared to the non-surveillance group (34.4% vs. 25.7%). Advanced adenoma recurrence was observed in 17 patients (4.4%) at follow-up. The risk of advanced adenoma recurrence was 2 times greater in patients with baseline advanced adenoma than in those with baseline non-advanced adenoma, though the difference was not statistically significant (6.8% [9/133] vs. 3.1% [8/254], P=0.09). Advanced adenoma recurrence was observed only in males and in subjects aged ≥50 years. In contrast, adenoma recurrence was observed in 187 patients (48.3%) at follow-up. Male sex, older age (≥50 years), and multiple adenomas (≥3) at baseline were independent risk factors for adenoma recurrence.

Conclusions

A colonoscopy surveillance interval of 3 years in patients with baseline advanced adenoma can be considered appropriate.