Characteristics and outcomes of endoscopically resected colorectal cancers that arose from sessile serrated adenomas and traditional serrated adenomas

Small sessile serrated polyps might not be at a higher risk for future advanced neoplasia than low-risk adenomas or polyp-free groups

BACKGROUND

Polypectomy surveillance colonoscopy is recommended according to the risk stratification of initially removed polyps. This study aimed to evaluate the risk of advanced neoplasia following low-risk SSPs compared with that following LRAs and polyp-free groups.

MATERIALS AND METHODS

From September 2013 to August 2017, asymptomatic Koreans aged 50-75 years who underwent surveillance colonoscopy post-baseline colonoscopy were enrolled. The 1314 participants who met the study design criteria were stratified into three groups according to the presence of LRAs or low-risk SSPs. The rate of advanced neoplasia was then compared between groups by surveillance colonoscopy.

RESULTS

A total of 1314 participants were classified according to baseline colonoscopy findings: no polyp (n = 551), LRA (n = 707), and low-risk SSP (n = 56). All participants underwent surveillance colonoscopy after an average of 28.1 ± 8.7 months. The rate of advanced neoplasia at surveillance was not different between groups: no polyp group (13/551, 2.4%), LRA group (27/707, 3.8%), and low-risk SSP group (0/56, 0%). The LRA group exhibited a significantly higher rate of low- and high-risk polyps (47.5, 13.4%) than did the no polyp (35.6, 7.4%, p < .001, p = .001), but no significant differences to the low-risk SSP group (35.7, 7.1%, p = .117, p = .253), respectively.

CONCLUSIONS

Patients with low-risk SSPs were not at a higher risk of advanced neoplasia than LRA patients, even in the polyp-free group. We suggest that surveillance colonoscopy after the removal of low-risk SSPs is not required more often than for LRAs.

The incidence and risk factors of sessile serrated adenomas in left side colon cancer patients after curative surgery

Sessile serrated adenomas (SSAs) are precursors of colorectal cancer (CRC). However, there are limited data on detection rates of this premalignant lesion during colonoscopy surveillance in patients with a history of left side colonic resection for cancer. We aimed to identify the incidence and risk factors of SSAs in post-left side colectomy patients.We retrospectively reviewed the medical records of patients who had undergone left side colectomy for colon and rectal cancer between September 2009 and September 2016 and had at least 1 follow-up colonoscopy. Patient baseline characteristics, SSA diagnoses and characteristics, and colonoscopy information were collected.In total, 539 patients were enrolled. At the first follow-up (mean duration 11.5 months), 98 SSAs were identified (22.2%). At the second follow-up (mean duration 25.8 months), 51 SSAs were identified in 212 patients (24.0%). Multivariate analysis showed that alcohol intake (hazard ratio [HR] 1.524; 95% confidence interval [CI] .963-2.411, P = .041), excellent bowel preparation (HR 2.081; 95% CI 1.214-3.567, P = .049), and use of a transparent cap (HR 1.702; 95% CI 1.060-2.735, P = .013) were associated with higher SSA incidence in the first surveillance colonoscopy, while body mass index (BMI) ≥ 25.0 (HR 1.602; 95% CI 1.060-2.836) was associated with a significantly increased risk of SSAs in the second surveillance.Considering the endoscopic appearance of SSAs, adequate bowel preparation and use of transparent caps during postoperative surveillance colonoscopy can increase the diagnosis rate. Modification of alcohol intake and BMI may reduce the incidence of SSAs in left side colon cancer patients.

Improved Real-Time Optical Diagnosis of Colorectal Polyps Following a Comprehensive Training Program

BACKGROUND & AIMS

The optimal training method for endoscopic characterization of colorectal polyps using narrow-band imaging is uncertain, and sessile serrated lesions (SSLs) optical diagnosis data are lacking. We aimed to evaluate a comprehensive training program for real-time optical diagnosis of colorectal polyps, including SSLs.

METHODS

We performed a single-institution prospective study of 15 endoscopists trained with the Workgroup Serrated Polyps and Polyposis classification system. After the first phase of in vivo optical diagnosis, their performances were evaluated. After re-education for insufficient competency, they began the second phase. The learning curves and performance on 2 preservation and incorporation of valuable endoscopic innovations benchmarks were assessed.

RESULTS

A total of 7294 polyps, including 486 SSLs, were diagnosed in real-time. The overall accuracy improved from 73.5% in the first phase to 77.1% in the second. The accuracy with high confidence was 79.4% and 85.1% in the first and second phases, respectively. In the first and second phases, the negative predictive values for diminutive neoplastic polyps were 82.1% and 92.5%, respectively, and concordances of the surveillance intervals were 80.7% and 89.7%, respectively. Eight endoscopists achieved the preservation and incorporation of valuable endoscopic innovations benchmarks after the second phase compared with none after the first. In contrast, the high confidence rate decreased from 74.6% to 70.2% as training progressed.

CONCLUSION

A comprehensive training program for real-time optical diagnosis significantly improved performance and reduced individual variability in less-experienced endoscopists. ClinicalTrials.gov no: NCT02516748.

Identification of risk factors for sessile and traditional serrated adenomas of the colon by using big data analysis

BACKGROUND AND AIM

Little is known about the risk factors associated with serrated polyps, because the early studies, which occurred before the new World Health Organization classification was introduced, included mixtures of serrated polyps. This study aimed to evaluate the risk factors associated with the presence of sessile serrated adenomas (SSAs) and traditional serrated adenomas (TSAs) using big data analytics.

METHODS

Using a case-control design, we evaluated the risk factors associated with the presence of SSAs and TSAs. Subjects who underwent colonoscopies from 2002 to 2012 as part of the comprehensive health screening programs undertaken at the Samsung Medical Center, Korea, participated in this study.

RESULTS

Of the 48 677 individuals who underwent colonoscopies, 183 (0.4%) had SSAs and 212 (0.4%) had TSAs. The multivariate analysis determined that being aged ≥ 50 years (odds ratio [OR] 1.91, 95% confidential interval [CI] 1.27-2.90, P = 0.002) and a history of colorectal cancer among first-degree relatives (OR 3.14, 95% CI 1.57-6.27, P = 0.001) were significant risk factors associated with the presence of SSAs and that being aged ≥ 50 years (OR 2.61, 95% CI 1.79-3.80, P < 0.001), obesity (OR 1.63, 95% CI 1.12-2.36, P = 0.010), and a higher triglyceride level (OR 1.63, 95% CI 1.12-2.36, P = 0.010) were independent risk factors associated with the presence of TSAs.

CONCLUSIONS

We used big data analytics to determine the risk factors associated with the presence of specific polyp subgroups, and individuals who have these risk factors should be carefully scrutinized for the presence of SSAs or TSAs during screening colonoscopies.

Clinical outcomes of surveillance colonoscopy for patients with sessile serrated adenoma

Background/Aims

Sessile serrated adenomas (SSAs) are known to be precursors of colorectal cancer (CRC). The proper interval of follow-up colonoscopy for SSAs is still being debated. We sought to determine the proper interval of colonoscopy surveillance in patients diagnosed with SSAs in South Korea.

Methods

We retrospectively reviewed the medical records of patients diagnosed with SSAs who received 1 or more follow-up colonoscopies. The information reviewed included patient baseline characteristics, SSA characteristics, and colonoscopy information.

Results

From January 2007 to December 2011, 152 SSAs and 8 synchronous adenocarcinomas were identified in 138 patients. The mean age of the patients was 62.2 years and 60.1% patients were men. SSAs were located in the right colon (i.e., from the cecum to the hepatic flexure) in 68.4% patients. At the first follow-up, 27 SSAs were identified in 138 patients (right colon, 66.7%). At the second follow-up, 6 SSAs were identified in 65 patients (right colon, 66.7%). At the 3rd and 4th follow-up, 21 and 11 patients underwent colonoscopy, respectively, and no SSAs were detected. The total mean follow-up duration was 33.9 months. The mean size of SSAs was 8.1±5.0 mm. SSAs were most commonly found in the right colon (126/185, 68.1%). During annual follow-up colonoscopy surveillance, no cancer was detected.

Conclusions

Annual colonoscopy surveillance is not necessary for identifying new CRCs in all patients diagnosed with SSAs. In addition, the right colon should be examined more carefully because SSAs occur more frequently in the right colon during initial and follow-up colonoscopies.

Endoscopic Resection of Cecal Polyps Involving the Appendiceal Orifice: A KASID Multicenter Study

BACKGROUND

Endoscopic resection of polyps located at the appendiceal orifice (AO) is challenging, and the feasibility and outcomes of endoscopic resection for cecal polyps involving AO are unconfirmed.

AIMS

We evaluated the feasibility and outcomes of endoscopic resection for cecal polyps involving AO.

METHODS

In this retrospective, multicenter study involving nine tertiary referral centers, we evaluated 131 patients who underwent endoscopic resection for cecal polyps involving AO.

RESULTS

The median size of polyps resected was 10 mm (range 3-60 mm). Endoscopic mucosal resection, endoscopic piecemeal mucosal resection, and endoscopic submucosal dissection were performed in 75 (57.3%), 31 (23.7%), and 5 (3.8%) patients, respectively. The en bloc resection rate was 68.7%. Endoscopic complete resection was achieved in 123 lesions (93.9%). Intraprocedural and delayed bleeding occurred in 14 (10.7%) and three patients (2.3%), respectively, and perforation occurred in two patients (1.5%). Seven patients (5.3%) underwent additional surgery because of treatment failure or recurrence. Polyps of ≥20 mm in size showed significantly higher rates of perforation and additional surgery (p < 0.05), and a lower rate of en bloc resection (p < 0.005). Patients with polyps involving ≥75% of AO circumference exhibited a significantly lower rate of en bloc resection (p < 0.001), and significantly higher rates of surgery and recurrence (p < 0.05). Recurrence during follow-up occurred in 12 patients (15.6%); polyps involving ≥75% of AO circumference were an independent risk factor for recurrence.

CONCLUSION

Endoscopic resection of cecal polyps involving AO is safe and effective in select patients.

Risk factors of missed colorectal lesions after colonoscopy

Several studies have reported a significant rate of missed colorectal polyps during colonoscopy. This study aimed to determine the variables that affect the miss rate of colorectal polyps.We performed a retrospective observational study of patients who, between January 2007 and December 2014, had undergone a second colonoscopy within 6 months of their first. In all patients, the first colonoscopy constituted a screening or surveillance colonoscopy as part of a health check-up, and the patients were referred to the endoscopic clinic if there were meaningful polyps. The miss rate of colorectal polyps was evaluated, as were the variables related to these missed lesions.Among 659 patients (535 men), the miss rate of colorectal polyps was 17.24% (372/2158 polyps), and 38.69% of patients (255/659 patients) had at least 1 missed polyp. The most common site for missed polyps was the ascending colon (29.8%), followed by the sigmoid colon (27.8%). The miss rate of polyps was higher in men [odds ratio (OR) = 1.611, 95% confidence interval (95% CI) = 1.024-2.536], patients with multiple polyps at their first colonoscopy (OR = 1.463, 95% CI = 0.992-2.157), and patients who had a history of polyps (OR = 23.783, 95% CI = 3.079-183.694). Multiple missed polyps were more frequently located in the right colon (OR = 2.605, 95% CI = 1.458-4.657), and the risk of sessile serrated adenoma/polyp was greater in the right colon (OR = 10.418, 95% CI = 2.073-52.353).Endoscopists should pay careful attention in patients who have multiple polyps and in those who have a history of polyps, because such patients are at a high risk of missed polyps in colonoscopy.

Derivation and validation of a risk scoring model to predict advanced colorectal neoplasm in adults of all ages

BACKGROUND AND AIMS

Little is known about how to include adults < 50 years in colonoscopy screening. This study aimed to derive a risk-scoring model incorporating laboratory indicators for metabolic risks to predict advanced colorectal neoplasia (ACN) in asymptomatic Korean adults both younger and older than 50 years.

METHODS

In this cross-sectional study, 70 812 consecutive adult recipients of a screening colonoscopy in a single health check-up center in Korea between 2003 and 2012 were enrolled. A risk score model was developed using multiple logistic regression model and internally validated.

RESULTS

Overall prevalence of ACN was 1.4% (956/70 812). A 15-point score model was developed to comprise age, sex, family history of colorectal cancer, smoking, body mass index, serum levels of fasting glucose, low-density lipoprotein cholesterol, and carcinoembryonic antigen. Based on the score, the validation cohort could be categorized into five risk groups (low, borderline, moderate, high, and very high) with an ACN prevalence of 0.7%, 1.3%, 2.7%, 6.6%, and 13.2%, respectively. Compared with the borderline risk group, the low-risk group showed a 50.3% reduced risk of ACN. Meanwhile, the moderate, high, and very high risk groups showed 2, 5, and 10-fold increased risk of ACN. The score showed significantly superior discriminative power than the Asian-Pacific colorectal screening score (P = 0.003).

CONCLUSIONS

Our scoring model based on both clinical and laboratory risk factors is useful for the prediction of ACN. This score may be used to include adults < 50 years in colonoscopy screening.