Unveiling the profound advantages of total neoadjuvant therapy in rectal cancer: a trailblazing exploration.

The standard treatments for locally advanced rectal cancer typically involved neoadjuvant therapy with either short-course radiation or long-course chemoradiation, followed by radical surgery and adjuvant chemotherapy. While the advancement of surgical techniques and the adoption of multimodal therapy have greatly contributed to reducing local failure, there has been limited improvement in overall survival, primarily due to the stagnation in systemic failure. In response to this challenge, a new strategy known as total neoadjuvant therapy (TNT) has emerged, involving the administration of both full-dose chemotherapy and radiation before surgery. It has shown promise in reducing systemic failure, enhancing tumor regression, and improving treatment adherence, ushering in a new era in the standard treatment of locally advanced rectal cancer. This review aims to summarize the evolution of multimodal treatments for locally advanced rectal cancer, ultimately converging into the current TNT strategy, and provides an assessment of the benefits and limitations of TNT based on available evidence, serving as a foundation for selecting the best treatment option.

RNA-Seq-Based Molecular Classification Analyses in Colorectal Cancer and Synchronous Adenoma.

Colorectal cancers (CRC) are classified into consensus molecular subtypes (CMS) based on gene expression profiles. The revised classification system iCMS was proposed by considering intrinsic epithelial status, microsatellite instability (MSI), and fibrosis. This study aimed to provide molecular evidence for the adenoma-carcinoma sequence concept by examining CRC and synchronous adenomas using iCMS. Epithelial CMS cell proportion was estimated using CiberSortx, an in silico cell fractionation method that included CMS cell types among the reference cell types. A random forest (RF) model estimated the posterior probabilities of CMS classes, which were compared with the CiberSortx results. Gene expression profiles of the published iCMS signature panel were retrieved from our dataset and subjected to heatmap clustering for classification. Bulk RNA sequencing data were collected from 29 adenocarcinomas and 11 adenoma samples. CiberSortx showed all CRC contained either CMS2 or CMS3 as the major epithelial cancer cell type. The RF model classified approximately half of the CRC as CMS4, whereas CMS4 was hardly detected by CiberSortx. Because they were enriched with myofibroblasts as per the CiberSortx classification, we tentatively designated them as iCMS2-F/iCMS3-F. iCMS coupled with the application of an in silico cell fractionation method can provide the molecular dissection of CRC and adenoma.

Short- and long-term outcomes of subtotal/total colectomy in the management of obstructive left colon cancer.

PURPOSE: Surgical management of obstructive left colon cancer (OLCC) is still a matter of debate. The classic Hartmann procedure (HP) has a disadvantage that requires a second major operation. Subtotal colectomy/total abdominal colectomy (STC/TC) with ileosigmoid or ileorectal anastomosis is proposed as an alternative procedure to avoid stoma and anastomotic leakage. However, doubts about morbidity and functional outcome and lack of long-term outcomes have made surgeons hesitate to perform this procedure. Therefore, this trial was designed to provide data for morbidity, functional outcomes, and long-term outcomes of STC/TC. METHODS: This study retrospectively analyzed consecutive cases of OLCC that were treated by STC/TC between January 2000 and November 2020 at a single tertiary referral center. Perioperative outcomes and long-term outcomes of STC/TC were analyzed. RESULTS: Twenty-five descending colon cancer (45.5%) and 30 sigmoid colon cancer cases (54.5%) were enrolled in this study. Postoperative complications occurred in 12 patients. The majority complication was postoperative ileus (10 of 12). Anastomotic leakage and perioperative mortality were not observed. At 6 to 12 weeks after the surgery, the median frequency of defecation was twice per day (interquartile range, 1-3 times per day). Eight patients (14.5%) required medication during this period, but only 3 of 8 patients required medication after 1 year. The 3-year disease-free survival was 72.7% and 3-year overall survival was 86.7%. CONCLUSION: The risk of anastomotic leakage is low after STC/TC. Functional and long-term outcomes are also acceptable. Therefore, STC/TC for OLCC is a safe, 1-stage procedure that does not require diverting stoma.

Clinical outcomes and prognostic factors of cone-beam CT-guided radiofrequency ablation for pulmonary metastases in colorectal cancer patients.

AIM: Radiofrequency ablation (RFA) has been increasingly used for the treatment of pulmonary metastases in various malignancies. METHODS: A retrospective analysis was performed to establish the safety and efficacy of cone-beam computed tomography (CBCT)-guided RFA in patients with metastatic colorectal cancer between 2016 and 2019, and the prognostic factors of local tumor control were assessed. RESULTS: A total of 31 patients with colorectal cancer underwent 48 sessions of lung RFA. The mean diameter of metastases targeted for RFA was 11 mm (range: 4-32), and the RFA was technically successful in 43 sessions (90%). There were 14 complications (29%), the majority of which required no intervention, with no cases of mortality. The median follow-up duration from RFA in the surviving 29 patients was 18.0 months. Only two patients (6%) died of disease progression, and the 3-year overall survival rate was 91% (95% CI: 83-99). Local tumor progression (LTP) of the RFA site was observed in 27%, and the LTP-free survival rates at 1 and 2 years were 81% (95% CI: 70-82) and 64% (95% CI: 50-77), respectively. Multivariate analysis showed that the progression of extra-RFA sites and the presence of extrapulmonary metastasis were independent prognostic factors significantly associated with LTP at RFA site. CONCLUSION: Lung RFA using CBCT guidance is a comparatively safe and effective option for the treatment of lung metastases from colorectal cancer. However, the control of extrapulmonary metastases should be accompanied by combined or sequential systemic treatment and local treatment.

Epidemiology, Risk Factors, and Prevention of Colorectal Cancer-An English Version.

Colorectal cancer (CRC) is the fourth most common malignancy in Korea and has been ranked as the third leading cause of cancer deaths in 2020. Although the incidence and mortality rates of CRC have decreased in recent years in Korea, it is still a significant public health burden. From the early 1990s until the mid-2000s, the 5-year relative survival of patients with CRC in Korea continuously increased. This finding appears to be a consequence of the successful introduction of a government-led screening program; the development of improved surgical techniques, anticancer drugs, and adjuvant treatment; and the advancement of medical resources and infrastructure along with economic growth. However, the improvement in survival has stagnated since the late 2000s. The recent coronavirus disease 2019 outbreak led to a reduction in hospital visits and screenings, which is expected to cause a stage shift to advanced disease stages and a worse prognosis for patients with CRC. Exploring modifiable environmental risk factors and appropriate screening test methods in Korea is necessary to overcome these challenges. Primary prevention through risk factor mediation and secondary prevention using suitable screening programs can help reduce the incidence and mortality rates of CRC.

Validation of a scoring system to predict bladder dysfunction after laparoscopic rectal cancer surgery.

PURPOSE: A recent trend in  urinary catheter management in patients who underwent laparoscopic rectal cancer surgery is early removal. However, some patients develop bladder dysfunction and require urinary re-catheterization. In 2016, a scoring system to predict bladder dysfunction after laparoscopic rectal cancer surgery was developed in our institution. The aim of this study was to demonstrate the validity of this scoring system and to determine the suitability of patients for early removal of urinary catheter. METHODS: A single-center, retrospective study from a prospective database was conducted on 234 patients who underwent elective laparoscopic rectal cancer surgery between January 2016 and December 2019. According to bladder dysfunction predictive score, the urinary catheter was removed on the first postoperative day (low-risk group) and fifth postoperative day (high-risk group). After catheter removal, all patients were managed using in-house protocols. RESULTS: Of 234 patients, 130 (55.6%) were classified as a low-risk group. The overall incidence of bladder dysfunction was 8.5% (11/130) in the low-risk group and 13.5% (14/104) in the high-risk group. CONCLUSION: The scoring system developed to predict bladder dysfunction showed good overall performance for discriminating between patients suitable or not for early removal of urinary catheter after laparoscopic rectal cancer surgery.

Comparison of blowhole colostomy and loop ostomy for palliation of acute malignant colonic obstruction.

PURPOSE: Surgery to create a stoma for decompression might be required for unresectable stage IV cancer patients with complete colonic obstruction. The aim of this study was to compare the results of blowhole colostomy with those of loop ostomy. METHODS: Palliative ileostomy or colostomy procedures performed at a single center between January 2011 and October 2020, were analyzed retrospectively. Fifty-nine patients were identified during this period. The demographic characteristics and outcomes between the blowhole colostomy group (n=24) and the loop ostomy group (n=35) were compared. RESULTS: The median operative time tended to be shorter in the blowhole colostomy group (52.5 minutes; interquartile range [IQR], 43-65) than in the loop ostomy group (60 minutes; IQR, 40-107), but the difference did not reach statistical significance (P=0.162). The median length of hospital stay was significantly shorter with blowhole colostomy (blowhole, 13 days [IQR, 9-23]; loop, 21 days [IQR, 14-37]; P=0.013). Mean cecum diameter was significantly larger in the blowhole group than in the loop group (8.83±1.91 cm vs. 6.78±2.36 cm, P=0.001), and the emergency operation rate was higher in the blowhole group than in the loop group (22 of 24 [91.7%] vs. 23 of 35 [65.7%], P=0.021). CONCLUSION: In surgical emergencies, diverting a blowhole colostomy can be safe and effective for palliative management of colonic obstruction in patients with end-stage cancer and might reduce the operative time in emergent situations.

Risk factors for hemorrhoidal disease among healthy young and middle-aged Korean adults.

Hemorrhoidal disease is a highly prevalent anorectal condition causing substantial discomfort, disability, and decreased quality of life. Evidence on preventable risk factors for hemorrhoidal disease is limited. We conducted a cross-sectional study of 194,620 healthy men and women who completed a health screening exam including colonoscopy in 2011-2017. We evaluated potential risk factors of hemorrhoidal disease, including lifestyle factors, medical history, birth history, gastrointestinal symptoms, and anthropometric measurements. The prevalence of hemorrhoidal disease was 16.6%, and it was higher in females than in males (17.2 vs. 16.3%; P < 0.001). Compared to men, the prevalence of hemorrhoidal disease was higher in parous women (adjusted odds ratio [OR] 1.06; 95% confidence interval [CI] 1.02-1.10), and lower in nulliparous women (adjusted OR 0.92; 95% CI 0.86-0.98). In the adjusted analyses, older age, female sex, smoking, overweight, and being hypertensive were independently associated with the presence of hemorrhoidal disease. The prevalence of hemorrhoidal disease was positively associated with body mass index and waist circumference in parous women. The prevalence of hemorrhoidal disease was higher in older age, females, ever-smokers, and hypertensive participants. The association of excess adiposity with the prevalence of hemorrhoidal disease differed by sex and parity.

Clinicopathological characteristics and outcomes of gastrointestinal stromal tumors with high progranulin expression.

BACKGROUND & AIMS: Progranulin (PGRN) is known to promote tumorigenesis and proliferation of several types of cancer cells. However, little is known about the clinicopathological features of patients with gastrointestinal stromal tumors (GISTs) with regard to PGRN expression. METHODS: A retrospective analysis was performed on patients with GISTs who underwent curative surgical resection between 2007 and 2017. PGRN expression was evaluated by immunohistochemical (IHC) analysis and semi-quantitatively categorized (no expression, 0; weak, 1+; moderate, 2+; strong, 3+). Tumors with a staining intensity of 2+ or 3+ were considered high PGRN expression. RESULTS: Fifty-four patients were analyzed; 31 patients (57%) were male. The median age at surgery was 60 years (range, 33-79), and the most common primary site was the stomach (67%). Thirty-five patients (65%) had spindle histology; 42 patients (78%) were separated as a high-risk group according to the modified National Institutes of Health (NIH) classification. High PGRN-expressing tumors were observed in 27 patients (50%), had more epithelioid/mixed histology (68% vs. 32%; p = 0.046), and KIT exon 11 mutations (76% vs. 24%; p = 0.037). Patients with high PGRN-expressing tumors had a worse recurrence-free survival (RFS) (36% of 5-year RFS) compared to those with low PGRN-expressing tumors (96%; p<0.001). Multivariate analysis showed that high PGRN expression and old age (>60 years) were independent prognostic factors for poor RFS. CONCLUSIONS: High PGRN-expressing GISTs showed more epithelioid/mixed histology and KIT exon 11 mutations. PGRN overexpression was significantly associated with poor RFS in patients with GISTs who underwent curative resection.

An Unusual Case of Colon Perforation With Multiple Transmural Ulcers After Use of Polmacoxib and Everolimus in a Metastatic Breast Cancer Patient.

Everolimus (Afinitor) is an inhibitor of mammalian target of rapamycin. Polmacoxib (Acelex) is a nonsteroidal anti-inflammatory drug that belongs to the cyclooxygenase-2 (COX-2) inhibitor family and is mainly used for treatment of arthritis. Intestinal perforation has not been reported previously as a complication of everolimus, and perforation of the lower intestinal tract caused by a selective COX-2 inhibitor is extremely rare. We present here a case of colon perforation that occurred after use of polmacoxib in a metastatic breast cancer patient who had been treated with everolimus for the preceding six months.

Routine Intraoperative Bacterial Culture May Be Needed in Complicated Appendicitis.

PURPOSE: Choosing the appropriate antibiotic is important for treatment of complicated appendicitis. However, increasing multidrug resistant bacteria have been a serious problem for successful treatment. This study was designed to identify bacteria isolated from patients with complicated appendicitis and reveal their susceptibilities for antibiotics and their relationship with patient clinical course. METHODS: This study included patients diagnosed with complicated appendicitis and examined the bacterial cultures and antimicrobial susceptibilities of the isolates. Data were retrospectively collected from medical records of Kangbuk Samsung Hospital from January 2008 to February 2018. RESULTS: The common bacterial species cultured in complicated appendicitis were as follows: Escherichia coli (n=113, 48.9%), Streptococcus spp. (n=29, 12.6%), Pseudomonas spp. (n=23, 10.0%), Bacteriodes spp. (n=22, 9.5%), Klebsiella (n=11, 4.8%), and Enterococcus spp. (n=8, 3.5%). In antibiotics susceptibility testing, the positive rate of extended-spectrum beta lactamase (ESBL) was 9.1% (21 of 231). The resistance rate to carbapenem was 1.7% (4 of 231), while that to vancomycin was 0.4% (1 of 231). E. coli was 16.8% ESBL positive (19 of 113) and had 22.1% and 19.5% resistance rates to cefotaxime and ceftazidime, respectively. Inappropriate empirical antibiotic treatment (IEAT) occurred in 55 cases (31.8%) and was significantly related with organ/space surgical site infection (SSI) (7 of 55, P=0.005). CONCLUSION: The rate of antibiotic resistance organisms was high in community-acquired complicated appendicitis in Koreans. Additionally, IEAT in complicated appendicitis may lead to increased rates of SSI. Routine intraoperative culture in patients with complicated appendicitis may be an effective strategy for appropriate antibiotic regimen.

Prognostic significance of USP10 and p14ARF expression in patients with colorectal cancer.

Ubiquitin-specific proteases (USPs) play an important role in fundamental cellular processes. Among these, USP10 is known for its association with tumor development and progression of multiple cancers. We aimed to investigate the clinical significance of USP10 expression in colorectal cancer and examined the potential link between USP10 and p14ARF in patients with colorectal cancer. USP10 and p14ARF protein expression was assessed via immunohistochemistry (IHC) on a tissue microarray from 280 colorectal cancer cases. IHC scores were evaluated by digital image analysis and compared with patients' outcomes. In addition, we examined DNA hypermethylation in colorectal cancer cell lines and tissues, which were matched with adjacent normal colon samples. USP10 expression was lost (USP10loss) in 18.6% of samples (52/280 cases), which was linked to lymphovascular invasion (p = 0.019) and distant metastases (p < 0.001). Similarly, loss of p14ARF expression (p14ARFloss) was associated with more advanced tumors. USP10 expression correlated positively with p14ARF expression (r = 0.617, p < 0.001). USP10loss, p14ARFloss, and dual loss of USP10 and p14ARF were significantly associated with shorter disease-free survival and overall survival in comparison to USP10intact, p14ARFintact, and dual loss of USP10 and p14ARF, respectively. Multivariate analysis revealed that USP10loss (p = 0.030) and dual loss of USP10 and p14ARF (p = 0.014) are independent prognostic factors for poor disease-free survival in colorectal cancer patients. Furthermore, aberrant hypermethylation of the USP10 promoter region was found in colorectal cancer cell lines and tissues. The present results suggest that USP10loss is a potential prognostic marker for colorectal cancer.

Prognostic Value of Progranulin in Patients with Colorectal Cancer Treated with Curative Resection.

Progranulin (PGRN) has been characterized as an autocrine growth and survival factor and is known to stimulate tumorigenesis and proliferation of several types of cancer cell. However, little is known about the prognostic role of PGRN in colorectal cancer (CRC). A retrospective analysis was performed for patients with colorectal cancer who underwent curative resection between May 2013 and June 2015. PGRN expression in tumor cells was semi-quantitatively categorized (no expression, 0; weak/focal, 1+; moderate/focal or diffuse, 2+; strong/diffuse, 3+), and high expression was considered for tumors graded ≥2+ staining intensity. A total of 109 patients (28 stage I, 32 stage II, and 49 stage III) were analyzed. Thirty-eight patients (35%) had tumors with high PGRN expression, and there was a trend of elevated pre-operative CEA and CA19-9 levels in patients with high PGRN-expressing tumors compared to those with low PGRN-expressing tumors (CEA, 49% vs. 21%; CA19-9, 21% vs. 7%). The 3-year recurrence-free survival (3Y-RFS) and overall survival rates were 83.7% (95% CI, 76.8-90.6) and 96.0% (95% CI, 92.3-99.7), respectively. Patients with high PGRN-expressing tumors had a worse rate of 3Y-RFS (66.8%) compared to those with low PGRN-expressing tumors (92.4%; p = 0.010). Multivariate analysis showed that high PGRN expression, age (>66 years), stage (III), and perineural invasion (+) were independent prognostic factors associated with poor RFS after adjusting for confounding factors including sex, MSI, tumor location, KRAS, and lympho-vascular invasion. PGRN overexpression was significantly associated with poor RFS in patients with CRC who have undergone curative resection.

Patient-Controlled Nutrition After Abdominal Surgery: Novel Concept Contrary to Surgical Dogma.

PURPOSE: According to surgical dogma, patients who are recovering from general anesthesia after abdominal surgery should begin with a clear liquid diet, progress to a full liquid diet and then to a soft diet before taking regular meals. We propose patient-controlled nutrition (PCN), which is a novel concept in postoperative nutrition after abdominal surgery. METHODS: A retrospective pilot study was conducted to evaluate the feasibility and effects of PCN. This study was carried out with a total of 179 consecutive patients who underwent a laparoscopic appendectomy between August 2014 and July 2016. In the PCN group, diet was advanced depending on the choice of the patients themselves; in the traditional group, diet was progressively advanced to a full liquid or soft diet and then a regular diet as tolerated. The primary endpoints were time to tolerance of regular diet and postoperative hospital stay. RESULTS: Time to tolerance of a regular diet (P < 0.001) and postoperative hospital stay (P < 0.001) showed statistically significant differences between the groups. Multivariate analysis using linear regression showed that the traditional nutrition pattern was the only factor associated with postoperative hospital stay (P < 0.001). Multivariate analysis using logistic regression showed that traditional nutrition was the only risk factor associated with prolonged postoperative hospital stay (≥3 days). CONCLUSION: After abdominal surgery, PCN may be a feasible and effective concept in postoperative nutrition. In our Early Recovery after Surgery program, our PCN concept may reduce the time to tolerance of a regular diet and shorten the postoperative hospital stay.

Association between oral health and colorectal adenoma in a screening population.

Although periodontal disease and gastrointestinal tract health are closely associated, few studies have investigated whether periodontitis is a risk factor for colorectal adenoma. The aim of this study was to investigate whether there is an association between periodontitis and the risk of colorectal adenoma in asymptomatic healthy people.From January 2013 to October 2015, we retrospectively enrolled 42,871 patients who underwent health screening at Kangbuk Samsung Hospital in South Korea. Demographic and clinical data were collected before colonoscopy. We calculated the odds ratio (OR) for adenoma in these patients.The median age was 39.3 ±â€Š8.7 years and 70.4% of the patients were men; 32.5% had a body mass index (BMI) 25.0 kg/m. The frequency of adenoma was 12% (n = 5136). A higher risk of adenoma was associated with the following factors: BMI 25.0 kg/m (OR 1.51, 95% confidence interval [CI]: 1.42-1.61), current smoker (OR 1.51, 95% CI: 1.42-1.61), former smoker (OR 1.28, 95% CI: 1.19-1.37), periodontitis (OR 1.95, 95% CI: 1.82-2.0), moderate alcohol intake (OR 1.8, 95% CI: 1.69-1.93), and heavy alcohol intake (OR 2.67, 95% CI: 2.24-3.18).Being male or a former or current smoker, alcohol intake above the moderate level, and periodontitis increase the risk of colorectal adenoma. These findings suggest that controlling oral disease is important to the prevention and management of colorectal adenoma. The findings of this study could be applied to risk stratification and colorectal cancer prevention programs, including screening guidelines.

Prospective analysis of delayed colorectal post-polypectomy bleeding.

BACKGROUNDS/AIMS: Although post-polypectomy bleeding is the most frequent complication after colonoscopic polypectomy, only few studies have investigated the incidence of bleeding prospectively. The aim of this study was to investigate the incidence of delayed post-polypectomy bleeding and its associated risk factors prospectively. METHODS: Patients who underwent colonoscopic polypectomy at Kangbuk Samsung Hospital from January 2013 to December 2014 were prospectively enrolled in this study. Trained nurses contacted patients via telephone 7 and 30 days after polypectomy and completed a standardized questionnaire regarding the development of bleeding. Delayed post-polypectomy bleeding was categorized as minor or major and early or late bleeding. Major delayed bleeding was defined as a > 2-g/dL drop in the hemoglobin level, requiring hospitalization for control of bleeding or blood transfusion; late delayed bleeding was defined as bleeding occurring later than 24 h after polypectomy. RESULTS: A total of 8175 colonoscopic polypectomies were performed in 3887 patients. Overall, 133 (3.4%) patients developed delayed post-polypectomy bleeding. Among them, 90 (2.3%) and 43 (1.1%) patients developed minor and major delayed bleeding, respectively, and 39 (1.0%) patients developed late delayed bleeding. In the polyp-based multivariate analysis, young age (< 50 years; odds ratio [OR] 2.10; 95% confidence interval [CI] 1.18-3.68), aspirin use (OR 2.78; 95% CI 1.23-6.31), and polyp size of > 10 mm (OR 2.45; 95% CI 1.38-4.36) were significant risk factors for major delayed bleeding, while young age (< 50 years; OR 2.6; 95% CI 1.35-5.12) and immediate bleeding (OR 3.3; 95% CI 1.49-7.30) were significant risk factors for late delayed bleeding. CONCLUSIONS: Young age, aspirin use, polyp size, and immediate bleeding were found to be independent risk factors for delayed post-polypectomy bleeding.

Hybrid Single-Incision Laparoscopic Colon Cancer Surgery Using One Additional 5 mm Trocar.

BACKGROUND: Single-incision laparoscopic surgery (SILS) is a feasible and safe procedure for colorectal cancer. However, SILS has some technical limitations such as collision between instruments and inadequate countertraction. We present a hybrid single-incision laparoscopic surgery (hybrid SILS) technique for colon cancer that involves use of one additional 5 mm trocar. METHODS: Hybrid SILS for colon cancer was attempted in 70 consecutive patients by a single surgeon between August 2014 and July 2016 at Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine. Using prospectively collected data, an observational study was performed on an intention-to-treat basis. RESULTS: Hybrid SILS was technically completed in 66 patients, with a failure rate of 5.7% (4/70). One patient was converted to open surgery for para-aortic lymph node dissection. Another was converted to open surgery due to severe peritoneal adhesion. An additional trocar was inserted for adhesiolysis in the other two cases. Median lengths of proximal and distal margins were 12.8 cm (interquartile range [IQR], 10.0-18.6), and 8.2 cm (IQR, 5.5-18.3), respectively. Median total number of lymph nodes harvested was 24 (IQR, 18-33). Overall rate of postoperative morbidity was 12.9%, but there were no Clavien-Dindo grade III or IV complications. There was no postoperative mortality or reoperation. Median postoperative hospital stay was 6 days (IQR, 5-7). CONCLUSIONS: Hybrid SILS using one additional 5 mm trocar is a safe and effective minimally invasive surgical technique for colon cancer. Experienced laparoscopic surgeons can perform hybrid SILS without a learning curve based on the formulaic surgical techniques presented in this article.

Is methylation analysis of SFRP2, TFPI2, NDRG4, and BMP3 promoters suitable for colorectal cancer screening in the Korean population?

BACKGROUND/AIMS: Colorectal cancer (CRC) screening using stool DNA was recently found to yield good detection rates. A multi-target stool DNA test (Cologuard®, Exact Sciences), including methylated genes has been recently approved by the U.S. Food and Drug Administration. The aim of this study was to validate these aberrantly methylated genes as stool-based DNA markers for detecting CRC and colorectal advanced adenoma (AA) in the Korean population. METHODS: A single-center study was conducted in 36 patients with AA; 35 patients with CRC; and 40 endoscopically diagnosed healthy controls using CRC screening colonoscopy. The methylation status of the SFRP2, TFPI2, NDRG4, and BMP3 promoters was investigated blindly using bisulfate-modified stool DNA obtained from 111 participants. Methylation status was investigated by methylation-specific polymerase chain reaction. RESULTS: Methylated SFRP2, TFPI2, NDRG4, and BMP3 promoters were detected in 60.0%, 31.4%, 68.8%, and 40.0% of CRC samples and in 27.8%, 27.8%, 27.8%, and 33.3% of AA samples, respectively. The sensitivities obtained using 4 markers to detect CRC and AA were 94.3% and 72.2%, respectively. The specificity was 55.0%. CONCLUSIONS: Our results demonstrate that the SFRP2, TFPI2, NDRG4, and BMP3 promoter methylation analysis of stool sample DNA showed high sensitivity but low specificity for detecting CRC and AA. Because of the low specificity, 4 methylated markers might not be sufficient for CRC screening in the Korean population. Further large-scale studies are required to validate the methylation of these markers in the Asian population and to find new markers for the Asian population.

Prospective Analysis of Minor Adverse Events After Colon Polypectomy.

BACKGROUND: The risks of minor adverse events (MAEs) such as abdominal pain and bloating after colon polypectomy (CP) are less clearly documented than major adverse events. However, these complications may cause significant discomfort during the performance of normal activities. We aimed to estimate the incidence of MAE, associated risk factors, and healthcare resource utilization after CP. METHODS: Patients who underwent CP were prospectively enrolled in this study. Trained nurses contacted patients by telephone at 7 and 30 days after the CP and administered a standardized questionnaire to obtain information regarding the development of complications. MAEs were defined as any discomfort the patient experienced after CP excluding major bleeding, perforation, and post-polypectomy coagulation syndrome. RESULTS: Among a total of 2716 patients, 2253 patients completed the interview at 7 and 30 days. MAEs occurred in 263 patients (11.7%) before day 7, among which the most common were abdominal pain (4.5%), rectal bleeding (2.8%), and bloating (2.6%). Cumulative incidence of MAEs was in 267 patients (11.9%) at 30 days. On multivariate analysis, female sex (odds ratio [OR] 2.24, 95% confidence interval [CI] 1.58-3.18) and use of meperidine (OR 1.54, 95% CI 1.04-2.27) were risk factors for the occurrence of MAEs. Two patients (0.7%) required hospital admission, 117 patients (43.8%) were treated medically in the outpatient clinic, and the majority at 148 patients (55.4%) experienced resolution of symptoms after observation. CONCLUSIONS: The post-CP MAE rate was as low as 11.8%. The MAEs occurred mainly in the first seven postoperative days and resulted in little use of healthcare resources.