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 coronavirus disease 2019 (COVID-19) pandemic has led to significant global casualties. This study examines the postoperative impact of COVID-19 on patients who underwent gastrointestinal surgery, considering their heightened vulnerability to infections and increased morbidity and mortality risk. Methods: This retrospective observational study was conducted at a tertiary center and patients who underwent gastrointestinal surgery between January 2022 and February 2023 were included. Postoperative COVID-19 infection was defined as the detection of severe acute respiratory syndrome coronavirus 2 RNA by RT-PCR within 14 days after surgery. Propensity score matching was performed including age, sex, American Society of Anesthesiology physical status classification, and emergency operation between the COVID-19-negative (–) and -positive (+) groups. Results: Following 1:2 propensity score matching, 21 COVID-19(+) and 42 COVID-19(–) patients were included in the study. In the COVID-19(+) group, the postoperative complication rate was significantly higher (52.4% vs. 23.8%, P = 0.023).Mechanical ventilator requirement, intensive care unit (ICU) admission, and readmission rate did not significantly differ between the 2 groups. The median length of ICU (19 days vs. 4 days, P < 0.001) and hospital stay (18 vs. 8 days, P = 0.015) were significantly longer in the COVID-19(+) group. Patients with COVID-19 had a 2.4 times higher relative risk (RR) of major complications than patients without COVID-19 (RR, 2.37; 95% confidence interval, 1.254–4.467; P = 0.015). Conclusion COVID-19 infection during the postoperative period in gastrointestinal surgery may have adverse outcomes which may increase the risk of major complications. Preoperative COVID-19 screening and protocols for COVID-19 prevention in surgical patients should be maintained.

Purpose: This study aimed to evaluate the predictive value of lymph node yield (LNY) for survival outcomes according to tumor response after preoperative chemoradiotherapy (PCRT) in patients with rectal cancer. Methods: This study was a retrospective study conducted in a tertiary center. A total of 1,240 patients with clinical stage II or III rectal cancer who underwent curative resection after PCRT between 2007 and 2016 were included. Patients were categorized into the good response group (tumor regression grade [TRG], 0–1) or poor response group (TRG, 2–3). Propensity score matching was performed for age, sex, and pathologic stage between LNY of ≥12 and LNY of <12 within tumor response group. The primary outcome was 5-year disease-free survival (DFS) and overall survival (OS). Results: LNY and positive lymph nodes were inversely correlated with TRG. In good responders, 5-year DFS and 5-year OS of patients with LNY of <12 were better than those with LNY of ≥12, but there was no statistical significance. In poor responders, the LNY of <12 group had worse survival outcomes than the LNY of ≥12 group, but there was also no statistical significance. LNY of ≥12 was not associated with DFS and OS in multivariate analysis. Conclusion LNY of <12 showed contrasting outcomes between the good and poor responders in 5-year DFS and OS. LNY of 12 may not imply adequate oncologic surgery or proper staging in rectal cancer patients treated by PCRT. Furthermore, a decrease in LNY should be comprehended differently according to tumor response.

Background: Although atherosclerosis is likely to be involved in the development of arterial thrombotic events in patients with essential thrombocythemia (ET), abdominal aortic calcification (AAC) has rarely been investigated. We evaluated the prevalence and clinical relevance of AAC at the time of ET diagnosis. Methods: This retrospective study included patients newly diagnosed with ET who underwent abdominal computed tomography (CT) at the time of diagnosis between January 2002 and December 2021 at Chungnam National University Hospital, Daejeon, Korea. CT images were reviewed and an aortic calcification score was assigned. Results: Of the 94 patients (median age, 62 yr; range, 18‒90 yr), AAC was detected in 62 (66.0%).AAC was most commonly mild (33.0%), followed by moderate (22.7%) and severe (5.3%).Old age [odds ratio (OR), 34.37; 95% confidence interval (CI), 12.32‒95.91; P ＜0.001] was an independent risk factor for AAC. The patients with AAC had a higher WBC count (11.8±4.7 vs. 9.7±2.9×109 /L, P =0.017), higher neutrophil-to-lymphocyte ratio (4.3±2.7 vs. 3.1±1.5, P=0.039), and higher JAK2V617F positivity (81.5% vs. 58.8%, P=0.020) compared to those without AAC. AAC was an independent risk factor for arterial thrombotic vascular events that occurred before or at diagnosis of ET (OR, 4.12; 95% CI, 1.11‒15.85; P=0.034). Conclusion AAC is common in patients with ET and is associated with arterial thrombotic events.

The Korean Society for Electrolyte and Blood Pressure Research, in collaboration with the Korean Society of Nephrology, has published a clinical practice guideline (CPG) document for hyponatremia treatment. The document is based on an extensive evidence-based review of the diagnosis, evaluation, and treatment of hyponatremia with the multidisciplinary participation of representative experts in hyponatremia with methodologist support for guideline development. This CPG consists of 12 recommendations (two for diagnosis, eight for treatment, and two for special situations) based on eight detailed topics and nine key questions. Each recommendation begins with statements graded by the strength of the recommendations and the quality of the evidence. Each statement is followed by rationale supporting the recommendations. The committee issued conditional recommendations in favor of rapid intermittent bolus administration of hypertonic saline in severe hyponatremia, the use of vasopressin receptor antagonists in heart failure with hypervolemic hyponatremia, and syndrome of inappropriate antidiuresis with moderate to severe hyponatremia, the individualization of desmopressin use, and strong recommendation on the administration of isotonic fluids as maintenance fluid therapy in hospitalized pediatric patients. We hope that this CPG will provide useful recommendations in practice, with the aim of providing clinical support for shared decision-making to improve patient outcomes.

Hemorrhoids are varicose veins of the rectum that are located in or near the anal canal and are covered by mucosa. They can occur at any age, are generally symptomless, and affect both sexes equally. Hemorrhoids are a common complaint among younger women and are more likely to occur during pregnancy and the menstrual cycle. In this article, we discuss the many approaches in the treatment of hemorrhoids. Laxatives, stool softeners, and fiber supplements are all considered safe for use by pregnant women. Moderate use of laxatives is also acceptable. Since there is a lack of sufficient evidence to support the safety and efficiency of topical medicines or oral phlebotomies during pregnancy, these treatments must to be utilized with an increased degree of extreme caution. In the case that considerable bleeding occurs, anal packing may be a straight forward and helpful operation to implement. A hemorhoidectomy is the treatment option for hemorrhoids that have become strangulated, badly thrombosed, or have bleeding that cannot be controlled.

The Korean Society for Electrolyte and Blood Pressure Research, in collaboration with the Korean Society of Nephrology, has published a clinical practice guideline (CPG) document for hyponatremia treatment. The document is based on an extensive evidence-based review of the diagnosis, evaluation, and treatment of hyponatremia with the multidisciplinary participation of representative experts in hyponatremia with methodologist support for guideline development. This CPG consists of 12 recommendations (two for diagnosis, eight for treatment, and two for special situations) based on eight detailed topics and nine key questions. Each recommendation begins with statements graded by the strength of the recommendations and the quality of the evidence. Each statement is followed by rationale supporting the recommendations. The committee issued conditional recommendations in favor of rapid intermittent bolus administration of hypertonic saline in severe hyponatremia, the use of vasopressin receptor antagonists in heart failure with hypervolemic hyponatremia, and syndrome of inappropriate antidiuresis with moderate to severe hyponatremia, the individualization of desmopressin use, and strong recommendation on the administration of isotonic fluids as maintenance fluid therapy in hospitalized pediatric patients. We hope that this CPG will provide useful recommendations in practice, with the aim of providing clinical support for shared decision-making to improve patient outcomes.

Background: Information on myelofibrotic and leukemic transformations in Korean Philadelphia chromosome-negative myeloproliferative neoplasms (Ph ‒ MPNs) is limited. Methods: This study retrospectively analyzed transformations in patients diagnosed with essential thrombocythemia (ET), polycythemia vera (PV) prefibrotic/early primary myelofibrosis (pre-PMF), or overt primary myelofibrosis (PMF) based on the 2016 World Health Organization criteria between January 1996 and December 2020 at Chungam National University Hospital, Daejeon, Korea. Results: A total of 351 patients (144 with ET, 131 with PV, 45 with pre-PMF, and 31 with PMF;204 men and 147 women) with a median age of 64 years (range, 15‒91 years) were followed for a median of 4.6 years (range, 0.2‒24.8 years). The 10-year incidence of overt myelofibrosis was higher in pre-PMF than in ET (31.3% and 13.7%, respectively; P =0.031) and PV (12.2%; P =0.003). The 10-year incidence of leukemic transformation was significantly higher in PMF than in ET (40.0% and 7.9%, respectively; P =0.046), pre-PMF (4.7%; P =0.048), and PV (3.2%; P =0.031). The 5-year incidence of leukemic transformation was higher in patients with secondary myelofibrosis (SMF) than in those with PMF (19.0% and 11.4%, respectively; P =0.040). The 5-year overall survival of patients with SMF was significantly worse than that of patients with pre-PMF (74% and 93%, respectively; P =0.027) but did not differ from that of patients with PMF (57%; P =0.744). Conclusion The rates and clinical courses of myelofibrotic and leukemic transformations in Korean patients with Ph ‒ MPN did not differ from those in Western populations.

Background: Non-palpable splenomegaly in patients with polycythemia vera (PV) has seldom been addressed. In this retrospective study, we evaluated non-palpable, volumetric splenomegaly defined based on age- and body surface area (BSA)–matched criteria in patients with PV diagnosed according to the 2016 World Health Organization diagnostic criteria. Methods: Patients with PV who underwent abdominal computed tomography (CT) and who had palpable splenomegaly at diagnosis from January 1991 to December 2020 at Chungnam National University Hospital were enrolled. The spleen volume of each patient was determined by volumetric analysis of abdominal CT and adjusted for the patient’s age and BSA. Then the degree of splenomegaly was classified as no splenomegaly, borderline volumetric splenomegaly, overt volumetric splenomegaly, or palpable splenomegaly. Results: Of the 87 PV patients enrolled, 15 (17.2%) had no splenomegaly, whereas 17 (19.5%), 45 (51.7%), and 10 (11.5%) had borderline volumetric, overt volumetric, and palpable splenomegaly, respectively. The degree of splenomegaly did not affect the cumulative incidence of thrombotic vascular events (10-year incidence: 7.7%, 0%, 22.3%, and 50.7%, respectively, P = 0.414). By contrast, splenomegaly tended to adversely affect myelofibrotic transformation (10-year cumulative incidence: 0%, 0%, 7.1%, and 30.3%, respectively, P = 0.062). Moreover, the cumulative incidence of myelofibrotic transformation was significantly higher in patients with overt volumetric or palpable splenomegaly than those with no or borderline volumetric splenomegaly (10-year incidence: 0% vs. 10.3%, respectively; 15-year incidence: 0% vs. 26.3%, respectively, P = 0.020). Overall survival (OS) differed among patients with different degrees of splenomegaly (15-year OS: 100%, 78.6%, 71.7%, and 51.9%, respectively, P = 0.021). Conclusion The degree of splenomegaly, including volumetric splenomegaly, based on ageand BSA-matched reference spleen volumes at diagnosis reflects disease progression in PV patients. Therefore, volumetric splenomegaly should be evaluated at the time of diagnosis and taken into consideration when predicting the prognosis of patients with PV.