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.

Objectives: . FDXR encodes mitochondrial ferredoxin reductase, which is associated with auditory neuropathy spectrum disorder (ANSD) and optic atrophy. To date, only two studies have described FDXR-related hearing loss. The auditory rehabilitation outcomes of this disease entity have not been investigated, and the pathophysiological mechanisms remain incompletely understood. Here we report a hearing-impaired individual with co-segregation of the FDXR variant and post-synaptic type ANSD, who underwent cochlear implantation (CI) with favorable outcomes. We suggest a possible pathophysiological mechanism of adult-onset ANSD involving mitochondrial dysfunction. Methods: . A 35-year-old woman was ascertained to have ANSD. Exome sequencing identified the genetic cause of hearing loss, and a functional study measuring mitochondrial activity was performed to provide molecular evidence of pathophysiology. Expression of FDXR in the mouse cochlea was evaluated by immunohistochemistry. Intraoperatively, electrically evoked compound action potential (ECAP) responses were measured, and the mapping parameters were adjusted accordingly. Audiological outcomes were monitored for over 1 year. Results: . In lymphoblastoid cell lines (LCLs) carrying a novel FDXR variant, decreased ATP levels, reduced mitochondrial membrane potential, and increased reactive oxygen species levels were observed compared to control LCLs. These dysfunctions were restored by administering mitochondria isolated from umbilical cord mesenchymal stem cells, confirming the pathogenic potential of this variant via mitochondrial dysfunction. Partial ECAP responses during CI and FDXR expression in the mouse cochlea indicate that FDXR-related ANSD is post-synaptic. As a result of increasing the pulse width during mapping, the patient’s CI outcomes showed significant improvement over 1-year post-CI. Conclusion . A novel FDXR variant associated with mitochondrial dysfunction and post-synaptic ANSD was first identified in a Korean individual. Additionally, 1-year post-CI outcomes were reported for the first time in the literature. Excellent audiologic results were obtained, and our results reiterate the correlation between genotype and CI outcomes in ANSD.

Post-tuberculosis lung disease (PTLD) is emerging as a significant area of global interest. As the number of patients surviving tuberculosis (TB) increases, the subsequent long-term repercussions have drawn increased attention due to their profound clinical and socioeconomic impacts. A primary obstacle to its comprehensive study has been its marked heterogeneity. The disease presents a spectrum of clinical manifestations which encompass tracheobronchial stenosis, bronchiectasis, granulomas with fibrosis, cavitation with associated aspergillosis, chronic pleural diseases, and small airway diseases—all persistent consequences of PTLD. The spectrum of symptoms a patient may experience varies based on the severity of the initial infection and the efficacy of the treatment received. As a result, the long-term management of PTLD necessitates a detailed and specific approach, addressing each manifestation individually—a tailored strategy. In the immediate aftermath (0–12 months after anti-TB chemotherapy), there should be an emphasis on monitoring for relapse, tracheobronchial stenosis, and smoking cessation. Subsequent management should focus on addressing hemoptysis, managing infection including aspergillosis, and TB-associated chronic obstructive pulmonary disease or restrictive lung function. There remains a vast expanse of knowledge to be discovered in PTLD. This review emphasizes the pressing need for comprehensive, consolidated guidelines for management of patients with PTLD.

Background/Aims: We evaluated the role of next-generation sequencing (NGS)-based disease monitoring for elderly patients diagnosed with acute myeloid leukemia (AML) who received decitabine therapy. Methods: A total of 123 patients aged > 65 years with AML who received decitabine were eligible. We analyzed the dynamics of variant allele frequency (VAF) in 49 available follow-up samples after the fourth cycle of decitabine. The 58.6% VAF clearance (Δ, [VAF at diagnosis − VAF at follow-up] × 100 / VAF at diagnosis) was the optimal cut-off for predicting overall survival (OS). Results: The overall response rate was 34.1% (eight patients with complete remission [CR], six of CR with incomplete hematologic recovery, 22 with partial responses, and six with morphologic leukemia-free status). Responders (n = 42) had significantly better OS compared with non-responders (n = 42) (median, 15.3 months vs. 6.5 months; p < 0.001). Of the 49 patients available for follow-up targeted NGS analysis, 44 had trackable gene mutations. The median OS of patients with ΔVAF ≥ 58.6% (n=24) was significantly better than that of patients with ΔVAF < 58.6% (n = 19) (20.5 months vs. 9.8 months, p = 0.010). Moreover, responders with ΔVAF ≥ 58.6% (n = 20) had a significantly longer median OS compared with responders with VAF < 58.6% (n = 11) (22.5 months vs. 9.8 months, p = 0.004). Conclusions This study suggested that combining ΔVAF ≥ 58.6%, a molecular response, with morphologic and hematologic responses can more accurately predict OS in elderly AML patients after decitabine therapy.

Objective: Dysphagia is a common clinical condition characterized by difficulty in swallowing. It is sub-classified into oropharyngeal dysphagia, which refers to problems in the mouth and pharynx, and esophageal dysphagia, which refers to problems in the esophageal body and esophagogastric junction. Dysphagia can have a significant negative impact one’s physical health and quality of life as its severity increases. Therefore, proper assessment and management of dysphagia are critical for improving swallowing function and preventing complications. Thus a guideline was developed to provide evidence-based recommendations for assessment and management in patients with dysphagia. Methods: Nineteen key questions on dysphagia were developed. These questions dealt with various aspects of problems related to dysphagia, including assessment, management, and complications. A literature search for relevant articles was conducted using Pubmed, Embase, the Cochrane Library, and one domestic database of KoreaMed, until April 2021. The level of evidence and recommendation grade were established according to the Grading of Recommendation Assessment, Development and Evaluation methodology. Results: Early screening and assessment of videofluoroscopic swallowing were recommended for assessing the presence of dysphagia. Therapeutic methods, such as tongue and pharyngeal muscle strengthening exercises and neuromuscular electrical stimulation with swallowing therapy, were effective in improving swallowing function and quality of life in patients with dysphagia. Nutritional intervention and an oral care program were also recommended. Conclusion This guideline presents recommendations for the assessment and management of patients with oropharyngeal dysphagia, including rehabilitative strategies.

Background: /Aim: Abdominal ultrasonography (USG) is recommended as a surveillance test for high-risk groups for hepatocellular carcinoma (HCC). This study aimed to analyze the current status of the national cancer surveillance program for HCC in South Korea and investigate the effects of patient-, physician-, and machine-related factors on HCC detection sensitivity. Methods: This multicenter retrospective cohort study collected surveillance USG data from the high-risk group for HCC (liver cirrhosis or chronic hepatitis B or C >40 years of age) at eight South Korean tertiary hospitals in 2017. Results: In 2017, 45 experienced hepatologists or radiologists performed 8,512 USG examinations. The physicians had a mean 15.0±8.3 years of experience; more hepatologists (61.4%) than radiologists (38.6%) participated. Each USG scan took a mean 12.2±3.4 minutes. The HCC detection rate by surveillance USG was 0.3% (n=23). Over 27 months of follow-up, an additional 135 patients (0.7%) developed new HCC. The patients were classified into three groups based on timing of HCC diagnosis since the 1st surveillance USG, and no significant intergroup difference in HCC characteristics was noted. HCC detection was significantly associated with patient-related factors, such as old age and advanced fibrosis, but not with physician- or machine-related factors. Conclusions This is the first study of the current status of USG as a surveillance method for HCC at tertiary hospitals in South Korea. It is necessary to develop quality indicators and quality assessment procedures for USG to improve the detection rate of HCC.

Gossypiboma, an infrequent surgical complication, describes a mass of cotton material inadvertently left in the body cavity after an operation. It is an extremely rare iatrogenic complication of nasal surgery, with only a few cases reported in literature to date. Here we present a case of gossypiboma in the nasal septum of a 35-year-old male patient who previously underwent septorhinoplasty fourteen years prior. He was treated by endoscopic endonasal surgery to remove the lesion. Pathologic findings showed a foreign body (gauze filament) with a giant cell reaction. This report will be helpful for treating patients with similar histories in the future.

Objective: Emergency medicine residents are expected to exhibit a poor health status due to excessive working hours and high stress. Because much of patient care depends on them, their health conditions will have a significant impact on patient outcomes. Our study was designed to analyze the health status of emergency medicine residents and the affecting factors using the 2019 Korean Emergency Medicine Residents Survey (KEMRS) results. Methods: The study evaluated the self-rated health-defined percentage of responders who thought they were in good health. Based on this response, the influencing factors were categorized statistically. These factors included personal characteristics, lifestyle (drinking, smoking, eating, sleeping, and exercise), and emotional stress. Results: Of a total of 384 respondents, 176 (46%) thought they were in good health. Participants who perceived themselves to be unhealthy included residents who were married, female, and those in the 3rd grade. Drinking and smoking were not perceived to affect health status, but regular exercise and proper eating patterns were seen to be positive influencing factors. Daytime sleepiness, depressive moods, and personal well-being were correlated with health status. Conclusion While personal characteristics and emotional problems cannot be changed easily, lifestyle changes can be made for better health. The health conditions of emergency residents have not been considered a matter of importance thus far. To overcome their health problems, responsible improvements in schedules and a program of long-term follow-ups need to be implemented, followed by training programs.