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.

Objective: This retrospective study aimed to investigate the prevalence of chronic endometritis, diagnosed using CD138 immunohistochemistry, among infertile women and to assess the association between chronic endometritis and recurrent implantation failure (RIF). Methods: In total, 266 patients who underwent hysteroscopy due to infertility between 2019 and 2020 were included in the analysis. Of these, 136 patients with RIF and 130 non-RIF patients were included in the study. CD138 immunohistochemistry test results, blood biomarkers (including natural killer cells, white blood cells, and the lymphocyte-to-neutrophil ratio), and data on pregnancy outcomes were obtained. If the CD138 test yielded a positive result, the patients received antibiotic treatment. Results: The overall proportion of CD138-positive patients was 32.7% (87/266). The CD138 positivity rate was not related to the number of cycles with implantation failure. In the RIF patient group, no significant associations were found between CD138 positivity and peripheral blood markers. The clinical pregnancy rates were similar between infertile women treated with antibiotics for chronic endometritis and those without chronic endometritis. Conclusion To improve the pregnancy rate in infertile patients, it may be helpful to combine CD138 testing with other laboratory tests and administer antibiotic treatment if the result is positive.

With an aging population, the number of patients with difficulty swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. 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, aided endoscopically, which may be an alternative to a nasogastric tube when enteral nutritional is required for 4 weeks or more. This paper is the first Korean clinical guideline for PEG. It was 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.

Background: For acute ischemic stroke (AIS) patients with history of prior stroke (PS) and diabetes mellitus (DM), intravenous recombinant tissue plasminogen activator (IV-tPA) therapy in the 3- to 4.5-hour window is off-label in Korea. This study aimed to assess the safety and efficacy of IV-tPA in these patients. Methods: Using data from a prospective multicenter stroke registry between January 2009 and March 2021, we identified AIS patients who received IV-tPA in the 3- to 4.5-hour window, and compared the outcomes of symptomatic intracranial hemorrhage (SICH), 3-month mortality, 3-month modified Rankin Scale (mRS) score 0-1 and 3-month mRS distribution between patients with both PS and DM (PS/DM, n=56) versus those with neither PS nor DM, or with only one (non-PS/DM, n=927). Results: The PS/DM group versus the non-PS/DM group was more likely to have a prior disability, hypertension, hyperlipidemia, coronary heart disease and less likely to have atrial fibrillation. The PS/DM and the non-PS/DM groups had comparable rates of SICH (0% vs. 1.7%; p>0.999) and 3-month mortality (10.7% vs. 10.2%; p=0.9112). The rate of 3-month mRS 0-1 was non-significantly lower in the PS/DM group than in the non-PS/DM group (30.4% vs. 40.7%; adjusted odds ratio [95% confidence interval], 0.81 [0.41-1.59]). Conclusions In the 3- to 4.5-hour window, AIS patients with PS/DM, as compared to those with non-PS/DM, might benefit less from IV-tPA. However, given the similar risks of SICH and mortality, IV-tPA in the late time window could be considered in patients with both PS and DM.

Purpose: Whether administering chemotherapy followed by tamoxifen plus a gonadotropin-releasing hormone (GnRH) agonist to treat patients with lower-risk hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer provides a greater benefit than administering tamoxifen plus GnRH agonist alone remains unclear. This study aimed to compare the outcomes of propensity score-matched (PSM) patients who underwent these 2 types of treatment plans. Methods: This retrospective study included patients treated at our institution between 2009 and 2019. Eligible patients had HR-positive, HER2-negative, invasive breast cancer who had undergone surgery. There were 579 patients with HR-positive, HER2-negative breast cancer who were treated with a GnRH agonist and tamoxifen; patients with pathologic N2 and those who received neoadjuvant chemotherapy were excluded. After 1:1 PSM of patients who underwent GnRH agonist treatment and tamoxifen with versus without chemotherapy, 122 patients from these 2 groups were analyzed. Survival rates were calculated using the Kaplan-Meier method and compared via the log-rank test. Results: After PSM, there were no significant differences in several baseline characteristics between the 2 groups. After a median follow-up of 62.8 months, the patients in both groups demonstrated similar outcomes with no significant difference in disease-free survival (P = 0.596). Conclusion Patients derived no significant survival benefit from undergoing a chemotherapy regimen before receiving tamoxifen and GnRH agonist therapy compared to forgoing such chemotherapy.

Purpose: Although the overall survival (OS) of breast cancer patients is increasing with improved detection and therapies, so is the risk of breast cancer patients developing subsequent malignancies. We investigated the OS of breast cancer survivors according to sites of second primary malignancies (SPM). The OS of the second primary hematologic malignancy (SPHM) was then compared with that of metastatic breast cancer (MBC). Methods: We retrospectively analyzed patients diagnosed with primary breast cancer between 1998 and 2019. Only those with SPM were eligible for analysis. First, the OS of patients with SPM diagnosed as the first event after the diagnosis of breast cancer was analyzed. Next, the OS of patients with SPHM, with or without breast cancer relapse, was compared with that of patients with MBC, matched using the propensity score. Results: Patients diagnosed with SPM without breast cancer relapse as the first event had a significantly better OS than did patients with MBC, but the OS of those with SPHM as the first event did not differ significantly from that of patients with MBC (hazard ratio [HR], 1.558; 95% confidence interval [CI], 0.856–2.839; P = 0.147). The OS of patients with SPHM with or without breast cancer relapse was worse than that of the MBC group after propensity score matching (HR, 1.954; 95% CI, 1.045–3.654; P = 0.036). Conclusion Prognosis of SPM diagnosed as the first event was statistically better than that of MBC, except in case of SPHM. Patients with SPHM, with or without MBC, showed poor OS before and after propensity score matching.

Background: This study aims to elucidate clinical features, therapeutic strategies, and prognosis of pineal parenchymal tumors (PPT) by analyzing a 30-year dataset of a single institution. Methods: We reviewed data from 43 patients diagnosed with PPT at Seoul National UniversityHospital between 1990 and 2020. We performed survival analyses and assessed prognostic factors. Results: The cohort included 10 patients with pineocytoma (PC), 13 with pineal parenchymaltumor of intermediate differentiation (PPTID), and 20 with pineoblastoma (PB). Most patients presented with hydrocephalus at diagnosis. Most patients underwent an endoscopic third ventriculostomy and biopsy, with some undergoing additional resection after diagnosis confirmation. Radiotherapy was administered with a high prevalence of gamma knife radiosurgery for PC and PPTID, and craniospinal irradiation for PB. Chemotherapy was essential in the treatment of grade 3 PPTID and PB. The 5-year progression-free survival rates for PC, grade 2 PPTID, grade 3 PPTID, and PB were 100%, 83.3%, 0%, and 40%, respectively, and the 5-year overall survival rates were 100%, 100%, 40%, and 55%, respectively. High-grade tumor histology was associated with lower survival rates. Significant prognostic factors varied among tumor types, with World Health Organization (WHO) grade and leptomeningeal seeding (LMS) for PPTID, and the extent of resection and LMS for PB. Three patients experienced malignant transformations. Conclusion This study underscores the prognostic significance of WHO grades in PPT. It is nec-essary to provide specific treatment according to tumor grade. Grade 3 PPTID showed a poor prognosis. Potential LMS and malignant transformations necessitate aggressive multimodal treatment and close-interval screening.

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.

Background: and Purpose To understand the characteristics of Korean patients with anti-3-hydroxy-3-methylglutaryl-coenxyme A reductase (HMGCR) myopathy, we measured antiHMGCR antibodies and analyzed the clinical, radiological, and pathological features of patients with anti-HMGCR myopathy. Methods: We measured titers of anti-HMGCR antibodies in the sera of 99 patients with inflammatory myopathy, 36 patients with genetic myopathy, and 63 healthy subjects using an enzyme-linked immunosorbent assay. We tested 16 myositis-specific autoantibodies (MSAs) in all patients with anti-HMGCR myopathy. Results: Positivity for the anti-HMGCR antibody was observed in 17 (4 males and 13 females) of 99 patients with inflammatory myopathy. The median age at symptom onset was 60 years.Ten (59%) of the patients with anti-HMGCR positivity had taken statins. The titer of antiHMGCR antibodies was significantly higher in the statin-naïve group (median=230 U/mL, interquartile range=170–443 U/mL) than in the statin-exposed group (median=178 U/mL, interquartile range=105–210 U/mL, p=0.045). The most common symptom was proximal muscle weakness in 15 patients (88%), followed by myalgia in 9 (53%), neck weakness in 4 (24%), dysphagia in 3 (18%), and skin lesions in 2 (12%). The median titer of anti-HMGCR antibody was 202 U/mL. We found eight different MSAs in nine (53%) patients. The median disease duration from symptom onset to diagnosis was significantly shorter in the MSA-positive group than in the MSA-negative group (p=0.027). Conclusions Our study was the first to measure anti-HMGCR antibodies in inflammatory myopathy. It has provided new findings, including the suggestion of the coexistence of other MSAs in Korean patients.