Korean Guidelines for Postpolypectomy Colonoscopic Surveillance: 2022 revised edition

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for managing advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of the limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: adenoma ≥10 mm in size; 3 to 5 (or more) adenomas; tubulovillous or villous adenoma; adenoma containing high-grade dysplasia; traditional serrated adenoma; sessile serrated lesion containing any grade of dysplasia; serrated polyp of at least 10 mm in size; and 3 to 5 (or more) sessile serrated lesions. More studies are needed to fully comprehend the patients who are most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

Clinical Practice Guideline for Percutaneous Endoscopic Gastrostomy / 대한소화기학회지

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous place­ment of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.

Clinical practice guidelines for percutaneous endoscopic gastrostomy

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tube removal for PEG based on the currently available clinical evidence.

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.

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.

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.

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.

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.

Clinical Outcomes of the Endoscopic Treatments for the Early Esophageal Carcinoma and Dysplasia

BACKGROUND/AIMS: Esophageal cancer and dysplasia are relatively rare in Korea, compared to other Far Eastern countries. So, the feasibility and safety of endoscopic treatments for these diseases is not well established in Korea. This study aimed to assess the technical feasibility, safety and the clinical outcomes of endoscopic treatment for esophageal epithelial lesions. MATERIALS AND METHODS: Between April 2005 and March 2013, 25 esophageal epithelial lesions from 22 patients were treated with endoscopic treatment such as endoscopic submucosal dissection or endoscopic mucosal resection. RESULTS: Of the 25 lesions, 11 lesions were treated with endoscopic submucosal dissection (ESD) (ESD group) and 14 lesions with endoscopic mucosal resection (EMR group). In the ESD group, the diagnosis was squamous cell carcinoma in 7 patients (64%), high grade dysplasia in 3 patients (27%), and low grade dysplasia in 1 patient (9%). In the EMR group, thediagnosis was squamous cell carcinoma in 8 patients (57%), high grade dysplasia in 2 patients (14%), and low grade dysplasia in 4 patients (29%). En bloc resection rates were 100% in ESD and 42.9% in EMR, respectively. For the median 12 months follow up period, there was no recurrence in the ESD group. However, there were three recurrences in the EMR group. CONCLUSIONS: Endoscopic treatment for esophageal epithelial lesions is safe and feasible therapeutic modalities. Especially, ESD can provide higher rate of en bloc and curative resection for early esophageal cancer and dysplasia.

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.

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.

Therapeutic Outcomes of Endoscopic Submucosal Dissection in Undifferentiated-type Early Gastric Cancer / 대한소화기학회지

BACKGROUND/AIMS: Endoscopic submucosal dissection (ESD) has been accepted as a standard treatment of early gastric cancer (EGC). However, the indication of ESD in undifferentiated-type EGC was controversial. The aim of this study was to evaluate the therapeutic outcomes of ESD in undifferentiated-type EGC according to expanded indication. METHODS: At Soonchunhyang University Bucheon Hospital, a total of 82 lesions in 81 patients with undifferentiated-type EGC were treated with ESD. The therapeutic outcomes of ESD were evaluated by resection method (en bloc resection; piecemeal resection), histologic curative resection, complications and recurrence rates after ESD. RESULTS: The rate on en bloc resection and complete resection rate were 87.8% (72/82) and 80.5% (66/82), respectively. In signet ring cell carcinoma, the complete resection rate was higher than those in poorly differentiated adenocarcinoma and poorly differentiated adenocarcinoma with signet ring cell features, but there was no statistical significance (89.3% vs. 75.0%, 76.7%; p=0.347). The lateral margin positivity rate in poorly differentiated adenocarcinoma, signet ring cell carcinoma and poorly differentiated adenocarcinoma with signet ring cell features were 12.5%, 3.6% and 13.3%, respectively (p=0.395). The vertical margin positivity rate were 12.5%, 3.6% and 10.0%, respectively (p=0.485). The overall recurrence rate was 3.0% during a mean follow-up period of 37.4 months. CONCLUSIONS: ESD may be considered as a feasible treatment for undifferentiated-type EGC according to expanded indication. The therapeutic outcome of ESD in undifferentiated-type EGC is likely to be favorable, though further longer follow-up studies are needed.

Advanced Neoplasm Detection and Its Associated Factors in Colonoscopic Surveillance of Endoscopically Resected Early Colorectal Cancer / 대한소화기학회지

BACKGROUND/AIMS: Early colon cancer can be effectively diagnosed and treated by colonoscopy, and surveillance colonoscopy is necessary to detect precursor lesions or new early colon cancer. We analyzed the surveillance results of patients with endoscopically resected early colon cancer to evaluate the detection rate of advanced neoplasia and its associated factors. METHODS: We conducted a retrospective study at Soonchunhyang University Seoul Hospital, from May 2003 to December 2011. Patients who underwent endoscopic resection for early colon cancer, showed mucosal and submucosal invasion on histopathologic examination, and received surveillance colonoscopy at least once were enrolled in the current study. Patients who underwent operation and those who were lost during surveillance period were excluded. RESULTS: Among a total of 305 patients diagnosed with early colon cancer, 211 patients met our inclusion criteria. Of these patients, 15 (7.1%) advanced neoplasias were detected at first colonoscopy. One hundred ninety-eight patients (93.8%) underwent surveillance colonoscopy within one year and 14 (7.0%) advanced neoplasias were detected in this group of patients. When patients with and without advanced neoplasia at first surveillance colonoscopy performed within one year were compared, inadequate bowel preparation (OR, 18.237; 95% CI, 3.741-88.895; p<0.001) and three or more colon polyps (OR, 9.479; 95% CI, 1.103-81.452; p=0.040) were significant risk factors for detecting advanced neoplasia. CONCLUSIONS: Considering the high detection rate of advanced neoplasia at first surveillance colonoscopy in patients with endoscopically resected early colon cancer, surveillance interval should be within one year, especially when the bowel preparation has been inadequate and three or more colon polyps have been detected.

The Early Onset of Disease May Be a Risk Factor for Decreased Bone Mineral Density in Patients with Inflammatory Bowel Disease

BACKGROUND/AIMS: The pathogenesis of bone loss in patients with inflammatory bowel disease (IBD) is complex, multifactorial, and only partly understood. We aimed to examine the extent and risk factors of bone mass reduction and to analyze the impact of early onset of a disease before attaining peak bone mass in IBD patients. METHODS: We compared the risk factors for osteoporosis and BMD at the lumbar spine and the hip bone in IBD patients. RESULTS: A total of 44 patients with IBD were enrolled. Twenty-one and 23 patients were diagnosed as IBD before and after the age of 30 and designated as group A and group B, respectively. Group A had significant bone mass reduction at the lumbar spine than group B (BMD, 1.01+/-0.10 vs. 1.14+/-0.17, p<0.01; T-score, -1.22+/-0.84 vs. -0.08+/-1.39, p<0.01; Z-score, -1.11+/-0.81 vs. -0.03+/-1.32, p<0.01, respectively). Multivariate analysis showed that patients diagnosed as IBD before the age of 30 had possible risk factor of bone mass reduction (hazard ratio, 3.96; p=0.06). CONCLUSIONS: Bone mass reduction was more severe in patients who were diagnosed with IBD before the age of 30 than in those diagnosed after the age of 30.

Aortoenteric Fistula Diagnosed by Double Balloon Enteroscopy: A Case Report

A secondary aortoenteric fistula (AEF) is a direct communication between the gastrointestinal tract and the aorta in a patient who has undergone major surgery on the aorta, often an aorta graft operation. We experienced a patient who had undergone graft interposition for abdominal aortic aneurysm and was admitted due to three episodes of hematemesis and following hamatochezia. Gastroscopy, colonoscopy, and radioactive iodine scan failed to identify the bleeding site in the patient. He was diagnosed with AEF by double balloon enteroscopy and recovered after surgical intervention.

Symptomatic Improvement of Diffuse Esophageal Spasm after Botulinum Toxin Injection / 대한소화기학회지

Diffuse esophageal spasm, an uncommon esophageal motility disorder, has recently been defined using high-resolution manometry. Patients with distal esophageal spasm usually complain of chest pain or dysphagia. The etiology and pathophysiology of this disorder are poorly known, and treatment options are limited. However, some options to improve symptoms are available, including endoscopic injection of botulinum toxin. Nevertheless, few reports have described the effects of endoscopic injection of botulinum toxin in patients with symptomatic diffuse esophageal spasm with clear endoscopic and high-resolution manometry images. Here, we report a case of diffuse esophageal spasm diagnosed with high-resolution manometry and treated by endoscopic injection of botulinum toxin with good results at the 7-month follow-up.

Influenza A (H1N1) 2009 Pandemic Calm Down the Prevalence of Acute Hepatitis A in the Latter Half of 2009: Korean Population Study / 대한소화기학회지

BACKGROUND/AIMS: There was a spiking incidence of acute hepatitis A (AHA) in 2009 summer, but it went down drastically after an outbreak of influenza A (H1N1). We assessed the relationship between 2009 H1N1 pandemic and AHA prevalence from August to December 2009. METHODS: We compared AHA cases nationwide and in our hospital for the period from the latter half of 2008 to the end of 2010. H1N1 cases in our hospital from August 2009 to December 2009 were included in the study and the correlation between 2009 H1N1 pandemic and AHA prevalence was assessed. RESULTS: The national surveillance system reported 2,233, 7,895, 15,231 and 7,660 AHA cases from 2007 to 2010, respectively. A similar trend was noted in our hospital in the same periods. Although the national total incidence was increased in 2009, it showed steep decreasing trend line in the final 21 weeks of 2009 (weeks 32-52), as compared with 2008 and 2010. The mean weekly incidence percentage (AHA cases in a week/total in a year) in weeks 32-52 of 2009 was 1.17+/-0.55%, significantly lower than that in 2008 and 2010 (1.61+/-0.43% and 1.56+/-0.51%; p<0.001). Furthermore, we found a significant negative correlation between 2009 H1N1 pandemic and AHA in our hospital for weeks 32-52 of 2009 (r=-0.597; p<0.001). CONCLUSIONS: The widespread occurrence of 2009 H1N1 pandemic highlighted the benefits of health care and good hygiene, such as effective hand washing and wearing of masks, which may have also interrupted hepatitis A virus transmission.

Hyperplastic Polyposis Syndrome Identified with a BRAF Mutation

Hyperplastic polyposis syndrome (HPS) is a rare condition characterized by the presence of numerous hyperplastic polyps (HPs) in the colon and rectum. Patients with HPS have an increased risk of colorectal cancer. This link is associated with gene mutations, especially B type Raf kinase (BRAF). However, a case of HPS associated with gene mutations has seldom been reported in Korea. Here, we describe a case of HPS in which a BRAF mutation was present in a 34-year-old woman. She had more than 110 HPs in the stomach and colorectum, which we removed. All of the polyps were diagnosed histologically as HPs, and no adenomatous or malignant changes were noted. We performed a BRAF and K-ras mutation analysis as well as a microsatellite analysis on the resected colon polyps. BRAF mutations were found in the resected colon polyps, but there was no evidence of K-RAS mutation or microsatellite instability.