Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients’ values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Purpose: The original eCura system was designed to stratify the risk of lymph node metastasis (LNM) after endoscopic resection (ER) in patients with early gastric cancer (EGC).We assessed the effectiveness of a modified eCura system for reflecting the characteristics of undifferentiated-type (UD)-EGC. Materials and Methods: Six hundred thirty-four patients who underwent non-curative ER for UD-EGC and received either additional surgery (radical surgery group; n=270) or no further treatment (no additional treatment group; n=364) from 18 institutions between 2005 and 2015 were retrospectively included in this study. The eCuraU system assigned 1 point each for tumors >20 mm in size, ulceration, positive vertical margin, and submucosal invasion <500 µm; 2 points for submucosal invasion ≥500 µm; and 3 points for lymphovascular invasion. Results: LNM rates in the radical surgery group were 1.1%, 5.4%, and 13.3% for the low-(0–1 point), intermediate- (2–3 points), and high-risk (4–8 points), respectively (P-fortrend<0.001). The eCuraU system showed a significantly higher probability of identifying patients with LNM as high-risk than the eCura system (66.7% vs. 22.2%; McNemar P<0.001).In the no additional treatment group, overall survival (93.4%, 87.2%, and 67.6% at 5 years) and cancer-specific survival (99.6%, 98.9%, and 92.9% at 5 years) differed significantly among the low-, intermediate-, and high-risk categories, respectively (both P<0.001). In the high-risk category, surgery outperformed no treatment in terms of overall mortality (hazard ratio, 3.26; P=0.015). Conclusions The eCuraU system stratified the risk of LNM in patients with UD-EGC after ER. It is strongly recommended that high-risk patients undergo additional surgery.

BACKGROUND: Current polymer-based drug-eluting stents (DESs) have fundamental issues about inflammation and delayed re-endothelializaton of the vessel wall. Substance-P (SP), which plays an important role in inflammation and endothelial cells, has not yet been applied to coronary stents. Therefore, this study compares poly lactic-co-glycolic acid (PLGA)-based everolimus-eluting stents (PLGA-EESs) versus 2-methacryloyloxyethyl phosphorylcholine (MPC)-based SP-eluting stents (MPC-SPs) in in-vitro and in-vivo models. METHODS: The morphology of the stent surface and peptide/drug release kinetics from stents were evaluated. The invitro proliferative effect of SP released from MPC-SP is evaluated using human umbilical vein endothelial cell. Finally, the safety and efficacy of the stent are evaluated after inserting it into a pig’s coronary artery. RESULTS: Similar to PLGA-EES, MPC-SP had a uniform surface morphology with very thin coating layer thickness (2.074 lm). MPC-SP showed sustained drug release of SP for over 2 weeks. Endothelial cell proliferation was significantly increased in groups treated with SP (n = 3) compared with the control (n = 3) and those with everolimus (n = 3) (SP:118.9 ± 7.61% vs. everolimus: 64.3 ± 12.37% vs. the control: 100 ± 6.64%, p < 0.05). In the animal study, the percent stenosis was higher in MPC-SP group (n = 7) compared to PLGA-EES group (n = 7) (MPC-SP: 28.6 ± 10.7% vs. PLGAEES: 16.7 ± 6.3%, p < 0.05). MPC-SP group showed, however, lower inflammation (MPC-SP: 0.3 ± 0.26 vs. PLGAEES: 1.2 ± 0.48, p < 0.05) and fibrin deposition (MPC-SP: 1.0 ± 0.73 vs. PLGA-EES: 1.5 ± 0.59, p < 0.05) around the stent strut. MPC-SP showed more increased expression of cluster of differentiation 31, suggesting enhanced reendothelialization. CONCLUSION Compared to PLGA-EES, MPC-SP demonstrated more decreased inflammation of the vascular wall and enhanced re-endothelialization and stent coverage. Hence, MPC-SP has the potential therapeutic benefits for the treatment of coronary artery disease by solving limitations of currently available DESs.

Purpose: Thyroid cancer incidence has increased in recent decades, and thyroid surgery is continuously evolving in response to demands for postoperative comfort and cosmesis. This study aimed to introduce a new surgical method for minimally invasive open bilateral total thyroidectomy (MI-BTT) using a unilateral 2.5–3.0 cm neck incision. Furthermore, we reported the surgical outcomes and postoperative quality of life (QoL) using a validated Korean translated Dermatology Life Quality Index (DLQI) questionnaire. Materials and Methods: We retrospectively evaluated 41 Asian patients who underwent MI-BTT for low-risk papillary thyroid cancer by a single surgeon from March 2019 to December 2021. Results: A total of 4 male and 37 female patients were included. The mean age and body mass index were 46.2±10.1 years and 23.3±3.3 kg/m2 , respectively. The average tumor size was 1.1±0.6 cm, and 36 patients (87.8%) had bilateral cancer. Twenty-three (56.1%) patients had occult central lymph node (CLN) metastasis in the final pathologic report, with the mean number of dissected CLNs being 7.2±6.5. Gross capsular extension was found in 6 patients (14.6%). Moreover, 28 patients (68.3%) received additional treatment after surgery with low or high doses of radioactive iodine. The average serum-stimulated thyroglobulin value identified during treatment was 1.57±2.30 ng/mL. The mean operation time was 78.0±13.9 minutes, and postoperative complications included transient hypocalcemia (36.6%), transient hoarseness (24.4%), and seroma (2.4%). The mean total DLQI score was 2.73±0.78, indicating a small effect on QoL. Conclusion MI-BTT is a novel, safe, and feasible technique to improve patient satisfaction for surgical scars and QoL.

Background/Aims: The eCura system, a scoring model for stratifying the lymph node metastasis risk after noncurative endoscopic resection for early gastric cancer (EGC), has been internally validated, primarily for differentiated-type EGC. We aimed to externally validate this model for undifferentiated-type EGC. Methods: This multicenter, retrospective cohort study included 634 patients who underwent additional surgery (radical surgery group, n=270) or were followed up without additional treatment (no additional treatment group, n=364) after noncurative endoscopic resection for undifferentiated-type EGC between 2005 and 2015. The lymph node metastasis and survival rates were compared according to the risk categories. Results: For the radical surgery group, the lymph node metastasis rates were 2.6%, 10.9%, and 14.8% for the low-, intermediate-, and high-risk eCura categories, respectively (p for trend=0.003). For the low-, intermediate-, and high-risk categories in the no additional treatment group, the overall survival (92.7%, 68.9%, and 80.0% at 5 years, respectively, p<0.001) and cancer-specific survival rates (99.7%, 94.7%, and 80.0% at 5 years, respectively, p<0.001) differed significantly. In the multivariate analysis, the hazard ratios (95% confidence interval) in the no additional treatment group relative to the radical surgery group were 3.18 (1.41 to 7.17; p=0.005) for overall mortality and 2.60 (0.46 to 14.66; p=0.280) for cancer-specific mortality in the intermediate-tohigh risk category. No such differences were noted in the low-risk category. Conclusions The eCura system can be applied to undifferentiated-type EGC. Close follow-up without additional treatment might be considered for low-risk patients, while additional surgery is recommended for intermediate- and high-risk patients.

Background/Aims: Although an association between achalasia and esophageal cancer has been reported, whether achalasia confers a substantial increase in mortality is unknown. Moreover, the causes of death related to achalasia have not been investigated. We performed this nationwide, population-based cohort study on achalasia because no such study has been performed since the introduction of high-resolution manometry in 2008. Methods: This study was performed using data extracted from the Korean National Health Insurance Service database, covering a 9-year period from 2009 to 2017. Control participants without a diagnostic code for achalasia were randomly selected and matched by sex and birth year at a case-to-control ratio of 1:4. Data on the cause of death from Statistics Korea were also analyzed. Results: The overall incidence of achalasia was 0.68 per 100,000 person-years, and the prevalence was 6.46 per 100,000 population. Patients with achalasia (n=3,063) had significantly higher adjusted hazard ratio (aHR) for esophageal cancer (aHR, 3.40; 95% confidence interval [CI], 1.25 to 9.22; p=0.017), pneumonia (aHR, 2.30; 95% CI, 1.89 to 2.81; p<0.001), aspiration pneumonia (aHR, 3.92; 95% CI, 2.38 to 6.48; p<0.001), and mortality (aHR, 1.68; 95% CI, 1.44 to 1.94; p<0.001). Esophageal cancer carried the highest mortality risk (aHR, 8.82; 95% CI, 2.35 to 33.16; p=0.001), while pneumonia had the highest non-cancer mortality risk (aHR, 2.28; 95% CI, 1.31 to 3.96; p=0.004). Conclusions In this nationwide study, achalasia was associated with increased risk of mortality.Esophageal cancer and pneumonia were the most common comorbidities and the major causes of death in patients with achalasia.

Background/Aims: Gastroesophageal reflux disease (GERD) is a common chronic gastrointestinal disorder that typically requires long-term maintenance therapy. However, little is known about patient preferences and satisfaction and real-world prescription patterns regarding maintenance therapy for GERD. Methods: This observational, cross-sectional, multicenter study involved patients from 18 referral hospitals in Korea. We surveyed patients who had been prescribed proton pump inhibitors (PPIs) for GERD for at least 90 days with a minimum follow-up duration of 1 year. The main outcome was overall patient satisfaction with different maintenance therapy modalities. Results: A total of 197 patients were enrolled. Overall patient satisfaction, patient preferences, and GERD health-related quality of life scores did not significantly differ among the maintenance therapy modality groups. However, the on-demand therapy group experienced a significantly longer disease duration than the continuous therapy group. The continuous therapy group demonstrated a lower level of awareness of potential adverse effects associated with PPIs than the on-demand therapy group but received higher doses of PPIs than the on-demand therapy group. The prescribed doses of PPIs also varied based on the phenotype of GERD, with higher doses prescribed for non-erosive reflux disease than erosive reflux disease. Conclusion Although overall patient satisfaction did not significantly differ among the different PPI maintenance therapy modality groups, awareness of potential adverse effects was significantly different between the on-demand and continuous therapy groups.

Background/Aims: It remains unclear which maintenance treatment modality is most appropriate for mild gastroesophageal reflux disease (GERD).We aimed to compare on-demand treatment with continuous treatment using a proton pump inhibitor (PPI) in the maintenance treatment for patients with non-erosive GERD or mild erosive esophagitis. Methods: Patients whose GERD symptoms improved after 4 weeks of standard dose PPI treatment were prospectively enrolled at 25 hospitals.Subsequently, the enrolled patients were randomly assigned to either an on-demand or a continuous maintenance treatment group, and followed in an 8-week interval for up to 24 weeks. Results: A total of 304 patients were randomized to maintenance treatment (continuous, n = 151 vs on-demand, n = 153). The primary outcome, the overall proportion of unwillingness to continue the assigned maintenance treatment modality, failed to confirm the noninferiority of on-demand treatment (45.9%) compared to continuous treatment (36.1%). Compared with the on-demand group, the GERD symptom and health-related quality of life scores significantly more improved and the overall satisfaction score was significantly higher in the continuous treatment group, particularly at week 8 and week 16 of maintenance treatment. Work impairment scores were not different in the 2 groups, but the prescription cost was less in the on-demand group. Serum gastrin levels significantly elevated in the continuous treatment group, but not in the on-demand group. Conclusions Continuous treatment seems to be more appropriate for the initial maintenance treatment of non-erosive GERD or mild erosive esophagitis than on-demand treatment. Stepping down to on-demand treatment needs to be considered after a sufficient period of continuous treatment.