Second-look endoscopy findings after endoscopic submucosal dissection for colorectal epithelial neoplasms

Background/Aims@#Although second-look endoscopy (SLE) is frequently performed after gastric endoscopic submucosal dissection (ESD) to prevent bleeding, no studies have reported SLE findings after colorectal ESD. This study aimed to investigate SLE findings and their role in preventing delayed bleeding after colorectal ESD. @*Methods@#Post-ESD ulcer appearances were divided into coagulation (with or without remnant minor vessels) and clip closure groups. SLE findings were categorized according to the Forrest classification (high-risk ulcer stigma [type I and IIa] and low-risk ulcer stigma [type IIb, IIc, III, or clip closure]), and risk factors for high-risk ulcer stigma were analyzed. @*Results@#Among the 375 cases investigated, SLEs were performed in 171 (45.6%) patients. The incidences of high-risk ulcer stigma and low-risk stigma were 5.3% (9/171) and 94.7% (162/171), respectively. During SLE, endoscopic hemostasis was performed more frequently in the high-risk ulcer stigma group than in the lowrisk ulcer stigma group (44.4% [4/9] vs. 1.9% [3/162], respectively; p < 0.001), but most of the endoscopic hemostasis in the high-risk ulcer stigma group (3/4, 75.0%) were prophylactic hemostasis. Post-ESD delayed bleeding occurred in three (0.8%) patients belonging to the SLE group, of which, one patient was from the high-risk stigma group and two were from the low-risk stigma group. @*Conclusions@#The incidence of high-risk ulcer stigma during SLE was low, and delayed bleeding occurred in, both, high-risk and low-risk groups of SLE. SLEs performed after colorectal ESD may not be effective in preventing delayed bleeding, and further prospective studies are needed to evaluate the efficacy of SLE in post-colorectal ESD.

Enteroscopy in Crohn’s Disease: Are There Any Changes in Role or Outcomes Over Time? A KASID Multicenter Study

Background/Aims@#Although balloon-assisted enteroscopy (BAE) enables endoscopic visualization of small bowel (SB) involvement in Crohn’s disease (CD), there is no data on the changes in outcomes over time. We therefore investigated the changes in BAE use on CD patients over different time periods in terms of its role and clinical outcomes. @*Methods@#We used a multicenter enteroscopy database to identify CD patients with SB involvement who underwent BAE (131 procedures, 116 patients). We compared BAE-related factors and outcomes between the first period (70 procedures, 60 patients) and the second period (61procedures, 56 patients). The specific cutoff point for dividing the two periods was 2007, when BAE guidelines were introduced. @*Results@#Initial diagnosis of SB involvement in CD was the most common indication for BAE during each period (50.0% vs 31.1%, p=0.034). The largest change was in the number of BAE uses for stricture evaluation and/or treatment, which increased significantly in the latter period (2.9% vs 21.3%, p=0.002). The diagnostic yield in patients with suspected CD was 90.7% in the first period and 95.0% in the second (p=0.695). More endoscopic interventions were performed in the second period than in the first (5.1% vs 17.6%, p=0.041). Enteroscopic success rates were high throughout (100% in the first period vs 80.0% in the second period, p>0.999). In the first and second periods, therapeutic plans were adjusted in 62.7% and 61.4% of patients, respectively. @*Conclusions@#The overall clinical indications, outcomes, and effectiveness of BAE were constant over time in CD patients with SB involvement, with the exception that the frequency of enteroscopic intervention increased remarkably.

Diode Laser—Can It Replace the Electrical Current Used in Endoscopic Submucosal Dissection? (with Video)

Background/Aims@#A new medical fiber-guided diode laser system (FDLS) is expected to offer high-precision cutting with simultaneous hemostasis. Thus, this study aimed to evaluate the feasibility of using the 1,940-nm FDLS to perform endoscopic submucosal dissection (ESD) in the gastrointestinal tract of an animal model. @*Methods@#In this prospective animal pilot study, gastric and colorectal ESD using the FDLS was performed in ex vivo and in vivo porcine models. The completeness of en bloc resection, the procedure time, intraprocedural bleeding, histological injuries to the muscularis propria (MP) layer, and perforation were assessed. @*Results@#The en bloc resection and perforation rates in the ex vivo study were 100% (10/10) and 10% (1/10), respectively; those in the in vivo study were 100% (4/4) and 0% for gastric ESD and 100% (4/4) and 25% (1/4) for rectal ESD, respectively. Deep MP layer injuries tended to occur more frequently in the rectal than in the gastric ESD cases, and no intraprocedural bleeding occurred in either group. @*Conclusions@#The 1,940-nm FDLS was capable of yielding high en bloc resection rates without intraprocedural bleeding during gastric and colorectal ESD in animal models.

The role of platelet to lymphocyte ratio and neutrophil to lymphocyte ratio in ulcerative colitis

Background/Aims@#Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) can serve as biomarkers for diagnosing and assessing disease activity in ulcerative colitis (UC). We investigated their clinical significance in UC. @*Methods@#We analyzed 48 patients with UC who underwent measurement of fecal calprotectin (FC) and endoscopy and 96 age- and sex-matched healthy controls. NLR and PLR were compared between the patients and healthy controls. The endoscopic activity was divided into 2 groups: group 1 (mild to moderate inflammation) and group 2 (severe inflammation) according to the Mayo endoscopic subscore in UC. @*Results@#To diagnose UC, the optimal cutoff of NLR and PLR was 2.26 (sensitivity 54.2%; specificity 90.6%; positive likelihood ratio 5.778, 95% confidence interval [CI] 2.944–11.339; area under the curve [AUC] 0.774, 95% CI, 0.690–0.859) and 179.8 (sensitivity 35.4%; specificity 90.6%; positive likelihood ratio 3.778, 95% CI 1.821–7.838; AUC 0.654, 95% CI 0.556–0.753), respectively. The optimal cutoff to differentiate group 1 and group 2 was 3.44, 175.9, and 453 µg/g for NLR, PLR, and FC, respectively (sensitivity, 63.6% vs. 90.9% vs. 81.8%; specificity, 81.1% vs. 78.4% vs. 73.0%; positive likelihood ratio, 3.364 vs. 4.205 vs. 3.027; AUC, 0.714 vs. 0.897 vs. 0.813). PLR had the highest AUC and positive likelihood ratio. @*Conclusions@#NLR and PLR help differentiate patients with UC from healthy controls. NLR, PLR, and FC indicate endoscopic activity and may reflect intestinal mucosal conditions.

Enteroscopy in Crohn’s Disease: Are There Any Changes in Role or Outcomes Over Time? A KASID Multicenter Study

Background/Aims@#Although balloon-assisted enteroscopy (BAE) enables endoscopic visualization of small bowel (SB) involvement in Crohn’s disease (CD), there is no data on the changes in outcomes over time. We therefore investigated the changes in BAE use on CD patients over different time periods in terms of its role and clinical outcomes. @*Methods@#We used a multicenter enteroscopy database to identify CD patients with SB involvement who underwent BAE (131 procedures, 116 patients). We compared BAE-related factors and outcomes between the first period (70 procedures, 60 patients) and the second period (61procedures, 56 patients). The specific cutoff point for dividing the two periods was 2007, when BAE guidelines were introduced. @*Results@#Initial diagnosis of SB involvement in CD was the most common indication for BAE during each period (50.0% vs 31.1%, p=0.034). The largest change was in the number of BAE uses for stricture evaluation and/or treatment, which increased significantly in the latter period (2.9% vs 21.3%, p=0.002). The diagnostic yield in patients with suspected CD was 90.7% in the first period and 95.0% in the second (p=0.695). More endoscopic interventions were performed in the second period than in the first (5.1% vs 17.6%, p=0.041). Enteroscopic success rates were high throughout (100% in the first period vs 80.0% in the second period, p>0.999). In the first and second periods, therapeutic plans were adjusted in 62.7% and 61.4% of patients, respectively. @*Conclusions@#The overall clinical indications, outcomes, and effectiveness of BAE were constant over time in CD patients with SB involvement, with the exception that the frequency of enteroscopic intervention increased remarkably.

Diode Laser—Can It Replace the Electrical Current Used in Endoscopic Submucosal Dissection? (with Video)

Background/Aims@#A new medical fiber-guided diode laser system (FDLS) is expected to offer high-precision cutting with simultaneous hemostasis. Thus, this study aimed to evaluate the feasibility of using the 1,940-nm FDLS to perform endoscopic submucosal dissection (ESD) in the gastrointestinal tract of an animal model. @*Methods@#In this prospective animal pilot study, gastric and colorectal ESD using the FDLS was performed in ex vivo and in vivo porcine models. The completeness of en bloc resection, the procedure time, intraprocedural bleeding, histological injuries to the muscularis propria (MP) layer, and perforation were assessed. @*Results@#The en bloc resection and perforation rates in the ex vivo study were 100% (10/10) and 10% (1/10), respectively; those in the in vivo study were 100% (4/4) and 0% for gastric ESD and 100% (4/4) and 25% (1/4) for rectal ESD, respectively. Deep MP layer injuries tended to occur more frequently in the rectal than in the gastric ESD cases, and no intraprocedural bleeding occurred in either group. @*Conclusions@#The 1,940-nm FDLS was capable of yielding high en bloc resection rates without intraprocedural bleeding during gastric and colorectal ESD in animal models.

Second-look endoscopy findings after endoscopic submucosal dissection for colorectal epithelial neoplasms

Background/Aims@#Although second-look endoscopy (SLE) is frequently performed after gastric endoscopic submucosal dissection (ESD) to prevent bleeding, no studies have reported SLE findings after colorectal ESD. This study aimed to investigate SLE findings and their role in preventing delayed bleeding after colorectal ESD. @*Methods@#Post-ESD ulcer appearances were divided into coagulation (with or without remnant minor vessels) and clip closure groups. SLE findings were categorized according to the Forrest classification (high-risk ulcer stigma [type I and IIa] and low-risk ulcer stigma [type IIb, IIc, III, or clip closure]), and risk factors for high-risk ulcer stigma were analyzed. @*Results@#Among the 375 cases investigated, SLEs were performed in 171 (45.6%) patients. The incidences of high-risk ulcer stigma and low-risk stigma were 5.3% (9/171) and 94.7% (162/171), respectively. During SLE, endoscopic hemostasis was performed more frequently in the high-risk ulcer stigma group than in the lowrisk ulcer stigma group (44.4% [4/9] vs. 1.9% [3/162], respectively; p < 0.001), but most of the endoscopic hemostasis in the high-risk ulcer stigma group (3/4, 75.0%) were prophylactic hemostasis. Post-ESD delayed bleeding occurred in three (0.8%) patients belonging to the SLE group, of which, one patient was from the high-risk stigma group and two were from the low-risk stigma group. @*Conclusions@#The incidence of high-risk ulcer stigma during SLE was low, and delayed bleeding occurred in, both, high-risk and low-risk groups of SLE. SLEs performed after colorectal ESD may not be effective in preventing delayed bleeding, and further prospective studies are needed to evaluate the efficacy of SLE in post-colorectal ESD.

Clinical outcomes of positive resection margin after endoscopic mucosal resection of early colon cancers

BACKGROUND/AIMS: When determining the subsequent management after endoscopic resection of the early colon cancer (ECC), various factors including the margin status should be considered. This study assessed the subsequent management and outcomes of ECCs according to margin status.METHODS: We examined the data of 223 ECCs treated by endoscopic mucosal resection (EMR) from 215 patients during 2004 to 2014, and all patients were followed-up at least for 2 years.RESULTS: According to histological analyses, the margin statuses of all lesions after EMR were as follows: 138 cases (61.9%) were negative, 65 cases (29.1%) were positive for dysplastic cells on the resection margins, and 20 cases (8.9%) were uncertain. The decision regarding subsequent management was affected not only by pathologic outcomes but also by the endoscopist’s opinion on whether complete resection was obtained. Surgery was preferred if the lesion extended to the submucosa (odds ratio [OR], 25.46; 95% confidence interval [CI], 7.09–91.42), the endoscopic resection was presumed incomplete (OR, 15.55; 95% CI, 4.28–56.56), or the lymph system was invaded (OR, 13.69; 95% CI, 1.76–106.57). Fourteen patients (6.2%) had residual or recurrent malignancies at the site of the previous ECC resection and were significantly associated with presumed incomplete endoscopic resection (OR, 4.59; 95% CI, 1.21–17.39) and submucosal invasion (OR, 5.14; 95% CI, 1.18–22.34).CONCLUSIONS: Subsequent surgery was associated with submucosa invasion, lymphatic invasion, and cancer-positive margins. Presumed completeness of the resection may be helpful for guiding the subsequent management of patients who undergo endoscopic resection of ECC.

Small Bowel Tumors and Polyposis: How to Approach and Manage? / 대한소화기학회지

Although small bowel the mainly occupies the most part of the gastrointestinal tract, small intestine tumors are rare, insidious in clinical presentation, and frequently represent a diagnostic and management challenge. Small bowel tumors are generally classified as epithelial, mesenchymal, lymphoproliferative, or metastatic. Familial adenomatous polyposis and Peutz-Jeghers syndrome are the most common inherited intestinal polyposis syndromes. Until the advent of capsule endoscopy (CE) and device-assisted enteroscopy (DAE) coupled with the advances in radiology, physicians had limited diagnostic examination for small bowel examination. CE and new radiologic imaging techniques have made it easier to detect small bowel tumors. DAE allows more diagnosis and deeper reach in small intestine. CT enteroclysis/CT enterography (CTE) provides information about adjacent organs as well as pictures of the intestinal lumen side. Compared to CTE, Magnetic resonance enteroclysis/enterography provides the advantage of soft tissue contrast and multiplane imaging without radiation exposure. Treatment and prognosis are tailored to each histological subtype of tumors.

Practice patterns and clinical significance of use of capsule endoscopy in suspected and established Crohn's disease

BACKGROUND/AIMS: Although the role of capsule endoscopy (CE) in Crohn's disease (CD) has expanded, CE is not used routinely for diagnosing and evaluating CD in Korea. We aimed to investigate current patterns of practice and evaluate the clinical significance of the use of CE in CD in Korean patients. METHODS: Among 651 CE procedures performed for various indications, we retrospectively analyzed the medical records of patients who underwent CE in 57 cases of suspected CD (sCD) and 14 cases of established CD (eCD). RESULTS: In the sCD group, CE was most commonly used for the initial diagnosis of CD (54.4%). Capsule retention was found in only 1 patient in the eCD group (1/71, 1.4%). In the sCD group, 28.1% of patients were diagnosed with CD on the basis of CE findings; other diseases diagnosed included tuberculous enteritis (7.0%), non-steroidal anti-inflammatory drug-induced enteropathy (5.3%), and other enteritis (17.5%). Only 11.5% of patients with eCD (14/122) underwent CE. The indication for CE in the 14 patients with eCD was to assess disease extent and activity. The overall diagnostic yield of CE was 59.7%. Therapeutic strategies were changed in 70.2% of patients in the sCD group and 50% of those in the eCD group based on CE findings. CONCLUSIONS: In clinical practice, CE was most commonly indicated for the initial diagnosis of CD and was not generally performed in patients with eCD. CE appears to be an effective diagnostic modality for evaluating sCD and is useful for determining therapeutic strategies for patients with sCD and those with eCD.

Complete STK11 Deletion and Atypical Symptoms in Peutz-Jeghers Syndrome

No abstract available.

History and Development of Accessories for Endoscopic Submucosal Dissection

Endoscopic submucosal dissection (ESD) procedure is composed of circumferential mucosal incision and submucosal dissection. A variety of endoscopic accessories are required to perform mucosal incision and submucosal dissection safely. As a result of the improvements in ESD devices and peripheral equipment and development of the ESD technique, ESD procedures have been performed extensively worldwide. Here I review the history of the development of accessories used in performing ESD procedures.

Eradication Rate by Duration of Third-line Rescue Therapy with Levofloxacin after Helicobacter pylori Treatment Failure in Clinical Practice / 대한소화기학회지

BACKGROUND/AIMS: This study evaluated the eradication rate of levofloxacin-containing rescue therapy by treatment duration in patients in whom previous first- and second-line treatment failed. METHODS: Fifty-five patients with persistent Helicobacter pylori infection after first-line therapy and second-line therapy were studied in a single referral academic center. We compared the eradication rates by the treatment duration of third-line therapy. RESULTS: Of 55 patients, 12 (21.8%) received rescue therapy for seven days, 24 (43.6%) received rescue therapy for 10 days, and 19 (34.5%) received rescue therapy for 14 days. The eradication rates of therapy with levofloxacin were 65.5% in the 55 enrolled patients and 73.5% in the 49 patients who underwent follow-up testing. In cases where follow-up testing was performed, the eradication rate of 7-day therapy was 58.3%, of 10-day 68.2%, and of 14-day therapy 93.3%. Eradication rate of 14-day therapy was higher than 7-day (p=0.06) and 10-day (p=0.108), but chance could not be ruled out in the difference among groups. CONCLUSIONS: This study showed somewhat increasing of H. pylori eradication rate by extending the duration of levofloxacin-containing rescue therapy to 14 days.

Feasibility and response of helical tomotherapy in patients with metastatic colorectal cancer

PURPOSE: To investigate the treatment outcome and the toxicity of helical tomotherapy (HT) in patients with metastatic colorectal cancer (mCRC). MATERIALS AND METHODS: We retrospectively reviewed 18 patients with 31 lesions from mCRC treated with HT between 2009 and 2013. The liver (9 lesions) and lymph nodes (9 lesions) were the most frequent sites. The planning target volume (PTV) ranged from 12 to 1,110 mL (median, 114 mL). The total doses ranged from 30 to 70 Gy in 10-30 fractions. When the alpha/beta value for the tumor was assumed to be 10 Gy for the biologically equivalent dose (BED), the total doses ranged from 39 to 119 Gy10 (median, 55 Gy10). Nineteen lesions were treated with concurrent chemotherapy (CCRT). RESULTS: With a median follow-up time of 16 months, the median overall survival for 18 patients was 33 months. Eight lesions (26%) achieved complete response. The 1- and 3-year local progression free survival (LPFS) rates for 31 lesions were 45% and 34%, respectively. On univariate analysis, significant parameters influencing LPFS rates were chemotherapy response before HT, aim of HT, CCRT, PTV, BED, and adjuvant chemotherapy. On multivariate analysis, PTV 48 Gy10 were associated with a statistically significant improvement in LFPS. During HT, four patients experienced grade 3 hematologic toxicities, each of whom had also received CCRT. CONCLUSION: The current study demonstrates the efficacy and tolerability of HT for mCRC. To define optimal RT dose according to tumor size of mCRC, further study should be needed.

A Case of Localized Amyloid Light-Chain Amyloidosis in the Small Intestine

Amyloidosis is characterized by the abnormal deposition of extracellular amyloid fibrils. Cases involving amyloid light-chain amyloidosis in the small intestine have been reported infrequently in Korea. Here, we report a case of localized light chain protein amyloidosis in the small intestine. Esophagogastroduodenoscopy, push enteroscopy, and capsule endoscopy revealed submucosal tumor-like lesions, multiple shallow ulcers, and several erosions in the distal duodenum and jejunum. An endoscopic biopsy established the diagnosis of amyloidosis. In through an immunohistochemical analysis, the presence of lambda light chain protein was detected. The patient had no evidence of an underlying clonal plasma cell disorder or additional organ involvement. Therefore, we concluded that the patient had localized amyloidosis of the small intestine.

Meckel's Diverticulum Diagnosed by Enteroscopy / 대한소화기학회지

No abstract available.

Long-Term Efficacy of Endoscopic Submucosal Dissection Compared with Surgery for Early Gastric Cancer: A Retrospective Cohort Study

BACKGROUND/AIMS: This study aimed to compare the outcomes of endoscopic submucosal dissection (ESD) and gastrectomy based on the two sets of indications for ESD, namely guideline criteria (GC) and expanded criteria (EC). METHODS: Between January 2004 and July 2007, 213 early gastric cancer (EGC) patients were enrolled in this study. Of these patients, 142 underwent ESD, and 71 underwent gastrectomy. We evaluated the clinical outcomes of these patients according to the criteria. RESULTS: The complication rates in the ESD and gastrectomy groups were 8.5% and 28.2%, respectively. The duration of hospital stay was significantly shorter in the ESD group than the gastrectomy group according to the GC and EC (p<0.001 and p<0.001, respectively). There was no recurrence in the ESD and gastrectomy groups according to the GC, and the recurrence rates in the ESD and gastrectomy groups were 4.7% and 0.0% according to the EC, respectively (p=0.279). The occurrence rates of metachronous cancer in the ESD and gastrectomy groups were 5.7% and 5.0% according to the GC (p=1.000) and 7.5% and 0.0% according to the EC (p=0.055), respectively. CONCLUSIONS: Based on safety, duration of hospital stay, and long-term outcomes, ESD may be an effective and safe first-line treatment for EGC according to the EC and GC.

Colon Cancer Screening with Image-Enhanced Endoscopy

Colorectal cancer (CRC) is a major cause of cancer mortality worldwide, and this has led to an increased use of screening colonoscopy. This screening has resulted in long-term risk reduction in asymptomatic individuals. However, endoscopists may fail to detect advanced adenomas or colon cancer during screening. The reasons that adenomas or cancers are missed are thought to be associated with the location of the lesions or the skills of the endoscopist. To address the limitations of white light endoscopy (WLE) for adenoma detection, advanced endoscopic images have recently been used. Image-enhanced endoscopies (IEEs), including the use of topical dyes, optical filtering, and ultramagnification, allow for gastrointestinal lesion analysis. Many studies have compared the adenoma detection rate (ADR) obtained by using WLE and IEE, but with different results. IEE can be used to help the endoscopist to improve their ADR in screening colonoscopy. This review examines the possible roles of image-enhanced colonoscopy in CRC screening.

Double-Balloon Enteroscopy in Elderly Patients: Is It Safe and Useful?

BACKGROUND/AIMS: Providers may be hesitant to perform double-balloon enteroscopy (DBE) in the elderly because the increased number of co-morbidities in this population poses a greater risk of complications resulting from sedation. There are limited data on the use of DBE in the elderly. Here, we assessed the safety and efficacy of DBE in the elderly compared to those in younger patients. METHODS: We retrospectively analyzed the medical records of 158 patients who underwent 218 DBEs. Patients were divided into an elderly group (age > or =65 years; mean 71.4+/-5.4; n=34; 41 DBEs) and a younger group (age <65 years; mean 39.5+/-13.5; n=124; 177 DBEs). RESULTS: In both groups, the most common indication for DBE was obscure gastrointestinal bleeding. Mucosal lesions (33.3% vs. 60.9%; P=0.002) were the most common finding in both groups, followed by tumors (30.8% vs. 14.1%; P=0.036). The elderly were more likely to receive interventional therapy (51.3% vs. 23.5%; P=0.001). The diagnostic yield of DBE was slightly higher in the elderly group (92.3% vs. 86.5%; P=0.422), but was not statistically significant. The therapeutic success rate of DBE was 100% in the elderly group compared to 87.5% in the younger group (P=0.536). The overall DBE complication rate was 1.8% overall, and this rate did not differ significantly between the groups (2.6% vs. 1.7%; P=0.548). CONCLUSIONS: DBE is safe and effective in the elderly, and has a high diagnostic yield and high therapeutic success rate.

Does Metformin Affect The Incidence of Colonic Polyps and Adenomas in Patients with Type 2 Diabetes Mellitus?

BACKGROUND/AIMS: Colorectal cancer (CRC) develops from colonic adenomas. Type 2 diabetes mellitus (DM) is associated with a higher risk of CRC and metformin decreases CRC risk. However, it is not certain if metformin affects the development of colorectal polyps and adenomas. This study aimed to elucidate if metforminaffects the incidence of colonic polyps and adenomas in patients with type 2 DM. METHODS: Of 12,186 patients with type 2 DM, 3,775 underwent colonoscopy between May 2001 and March 2013. This study enrolled 3,105 of these patients, and divided them in two groups: 912 patients with metformin use and 2,193 patients without metformin use. Patient clinical characteristics, polyp and adenoma detection rate in the two groups were analyzed retrospectively. RESULTS: The Colorectal polyp detection rate was lower in the metformin group than in the non-meformin group (39.4% vs. 62.4%, P<0.01). Colorectal adenoma detection rate was significantly lower in the metformin group than in the non-metformin group (15.2% vs. 20.5%, P<0.01). Fewer advanced adenomas were detected in the metformin group than in the non-metformin group (12.2% vs. 22%, P<0.01). Multivariate analysis identified age, sex, Body mass index and metformin use as factors associated with polyp incidence, whereas only metforminwas independently associated with decreased adenoma incidence (Odd ratio=0.738, 95% CI=0.554-0.983, P=0.03). CONCLUSIONS: In patients with type 2 DM, metformin reduced the incidence of adenomas that may transform into CRC. Therefore, metformin may be useful for the prevention of CRC in patients with type 2 DM.