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.

Background: During the coronavirus disease 2019 (COVID-19) pandemic, patients with myasthenia gravis (MG) were more susceptible to poor outcomes owing to respiratory muscle weakness and immunotherapy. Several studies conducted in the early stages of the COVID-19 pandemic reported higher mortality in patients with MG compared to the general population. This study aimed to investigate the clinical course and prognosis of COVID-19 in patients with MG and to compare these parameters between vaccinated and unvaccinated patients in South Korea. Methods: This multicenter, retrospective study, which was conducted at 14 tertiary hospitals in South Korea, reviewed the medical records and identified MG patients who contracted COVID-19 between February 2022 and April 2022. The demographic and clinical characteristics associated with MG and vaccination status were collected. The clinical outcomes of COVID-19 infection and MG were investigated and compared between the vaccinated and unvaccinated patients. Results: Ninety-two patients with MG contracted COVID-19 during the study. Nine (9.8%) patients required hospitalization, 4 (4.3%) of whom were admitted to the intensive care unit. Seventy-five of 92 patients were vaccinated before contracting COVID-19 infection, and 17 were not. During the COVID-19 infection, 6 of 17 (35.3%) unvaccinated patients were hospitalized, whereas 3 of 75 (4.0%) vaccinated patients were hospitalized (P < 0.001). The frequencies of ICU admission and mechanical ventilation were significantly lower in the vaccinated patients than in the unvaccinated patients (P = 0.019 and P = 0.032, respectively). The rate of MG deterioration was significantly lower in the vaccinated patients than in the unvaccinated patients (P = 0.041). Logistic regression after weighting revealed that the risk of hospitalization and MG deterioration after COVID-19 infection was significantly lower in the vaccinated patients than in the unvaccinated patients. Conclusion This study suggests that the clinical course and prognosis of patients with MG who contracted COVID-19 during the dominance of the omicron variant of COVID-19 may be milder than those at the early phase of the COVID-19 pandemic when vaccination was unavailable. Vaccination may reduce the morbidity of COVID-19 in patients with MG and effectively prevent MG deterioration induced by COVID-19 infection.

Purpose: This study examined the factors affecting valgus deformities after arthroscopic reduction and internal fixation (ARIF) in lateral joint-depression tibial plateau fractures. Materials and Methods: Patients with lateral joint-depression tibial plateau fractures treated with ARIF were assessed retrospectively. The radiological evaluations included the articular depression distance (ADD) and the lateral plateau widening distance (LPWD) on preoperative and postoperative computed tomography. A postoperative valgus deformity was defined as valgus malalignment (mechanical axis ≥3°) and valgus deviation (Δmechanical axis of the operated knee from the healthy knee of ≥5°). Subgroup analyses based on a postoperative valgus deformity were performed to compare the clinical outcomes, including the range of motion, patient-reported outcomes measures, and failure and osteoarthritis progression. Furthermore, factors affecting the postoperative mechanical and Δmechanical axes were assessed. Results: Thirty-nine patients were included with a mean follow-up of 44.6 months (range, 24-106 months). Valgus malalignment and valgus deviation were observed after ARIF in 10 patients (25.6%) and five patients (12.8%), respectively. The clinical outcomes were similar in patients with and without a postoperative valgus deformity. On the other hand, lateral compartment osteoarthritis progression was significantly higher in the valgus deformity group than in the non-valgus deformity group (valgus malalignment group: 50.0% vs 6.9%, p=0.007; valgus deviation group: 60.0% vs 11.8%, p=0.032).One patient with valgus deformity underwent realignment surgery at postoperative five years. The preoperative ADD and postoperative LPWD were significantly associated with the postoperative mechanical (both, p<0.001) and Δmechanical (ADD, p=0.001; LPWD, p=0.025) axes. Moreover, the lateral meniscectomized status during ARIF was significantly associated with the Δmechanical axis (p=0.019). Conclusion Osteoarthritis progression was highly prevalent in patients with postoperative valgus deformity. Thus, the restoration of lateral plateau widening and articular depression and preservation of the meniscus are necessary to prevent a valgus deformity after ARIF in lateral joint-depression tibial plateau fractures.

Interleukin-1 receptor-associated kinase 4 (IRAK4) is a pivotal enzyme in the Toll-like receptor (TLR)/MYD88 dependent signaling pathway, which is highly activated in rheumatoid arthritis tissues and activated B cell-like diffuse large B-cell lymphoma (ABC-DLBCL). Inflammatory responses followed by IRAK4 activation promote B-cell proliferation and aggressiveness of lymphoma. Moreover, proviral integration site for Moloney murine leukemia virus 1 (PIM1) functions as an anti-apoptotic kinase in propagation of ABC-DLBCL with ibrutinib resistance. We developed a dual IRAK4/PIM1 inhibitor KIC-0101 that potently suppresses the NF-κB pathway and proinflammatory cytokine induction in vitro and in vivo. In rheumatoid arthritis mouse models, treatment with KIC-0101 significantly ameliorated cartilage damage and inflammation. KIC-0101 inhibited the nuclear translocation of NF-κB and activation of JAK/STAT pathway in ABC-DLBCLs. In addition, KIC-0101 exhibited an anti-tumor effect on ibrutinib-resistant cells by synergistic dual suppression of TLR/MYD88-mediated NF-κB pathway and PIM1 kinase. Our results suggest that KIC-0101 is a promising drug candidate for autoimmune diseases and ibrutinib-resistant B-cell lymphomas.

Objectives: Adenosine triphosphate-binding cassette subfamily G member 2 (ABCG2) and CD133 are recognized stem cell markers of gastric cancer. Extensive research has examined the significance of these markers in different types of cancers and their impact on prognoses, linking them to unfavorable clinical outcomes in various tumors. However, the prognostic value of these markers for gastric cancer remains unclear. We investigated the expression of ABCG2 and CD133 and their relationship with clinical outcomes in gastric cancer. Methods: ABCG2 and CD133 expression levels were analyzed, using immunohistochemistry and tissue microarrays, in tumor samples from 459 patients who underwent surgical resections due to gastric cancer. ABCG2 and CD133 expression levels were defined by intensity and dichotomized as medians. The associations among the expression levels of these markers, disease severity, and patient survival were also determined. Results: In the 411 patients for whom we analyzed the expression levels of these markers, 74.9% and 80.5% were found to have high levels of ABCG2 and CD133, respectively. High expression levels of ABCG2 and CD133 were more commonly observed in well-differentiated (p<0.001 and p=0.004, respectively) and intestinal lesions (p<0.001 and p=0.002, respectively). High ABCG2 expression correlated with improved survival outcomes, whereas high CD133 expression was associated with poorer outcomes. Cox regression analysis confirmed that stage, high ABCG2 (overall survival [OS]: hazard ratio [HR], 0.61; 95% confidence interval [CI], 0.41–0.91; p=0.015; recurrencefree survival [RFS]: HR, 0.55; 95% CI, 0.34–0.88; p=0.012), and CD133 expression (OS: HR, 1.59; 95% CI, 1.00–2.51; p=0.049; RFS: HR, 2.29; 95% CI, 1.21–4.34; p=0.011) were predictors of survival. A subgroup analysis indicated that ABCG2 expression was also associated with an improved RFS rate in patients who received systemic chemotherapy. Conclusions High ABCG2 expression and low CD133 expression in tumors correlated with improved survival outcomes in post-resection patients with gastric cancer, suggesting their potential utility as prognostic biomarkers.

Purpose: The outcomes of non-trauma patients requiring intra-abdominal gauze packing for the management of uncontrollable hemorrhage following surgery, and the evaluation of survival risk factors were examined. Methods: Data from patients who underwent intra-abdominal gauze packing to control bleeding during abdominal surgery between September 2012 and March 2019 were retrospectively reviewed. Results: A total of 28 patients were included in the study population analysis. There were 9 patients who died during hospitalization. One patient died as a result of uncontrolled bleeding. In spite of gauze packing, 2 patients who had increasing blood transfusion requirements (> 4 packs/4 hours) were found to have arterial bleeding. Univariate analysis for hospital death showed that immunocompromised status, emergency surgery, a thrombocytopenic state prior to initial surgery, and a longer duration until gauze removal had a negative association with survival outcomes. Among these factors, only time to gauze removal > 36 hours was identified as an independent risk factor for survival outcome in the multivariate analysis. Conclusions Gauze packing could be considered as an effective method for the management of uncontrolled hemorrhage, in non-trauma patients. In cases of persistent bleeding after gauze packing, arterial bleeding should be suspected. Gauze removal after > 36 hours may indicate a poor survival outcome.

Purpose: To evaluate the long-term clinical results and survivorship of unicompartmental knee arthroplasty (UKA) in elderly patients older than 70 years by analyzing cases that have been implanted for >10 years ago. Materials and Methods: The long-term follow-up results were evaluated in 39 patients (46 cases) who underwent medial UKA from March 2002 to February 2004. The mean age of the patients at the time of surgery was 74.0 years, and the preoperative diagnosis was degenerative arthritis of the knee in all cases. Results: Of the 46 cases, reoperation occurred due to the complications in four cases. In 22 cases without 14 cases of death and six cases of follow-up loss, follow-up more than 10 years was possible. The mean Knee Society knee and function scores improved significantly from 53.0 and 52.5 points pre-operatively to 89.4 and 80.9 points at the last follow-up, respectively (p<0.001). The mean range of motion of the knee recovered to 132.5°, and the mean tibiofemoral angle changed to 5.9° of valgus at the last follow-up. Complications following the UKA occurred in four cases; the most prevalent complication was mobile bearing dislocation (n=2). One case of failure occurred due to aseptic loosening and degenerative arthritis of the lateral compartment, respectively. The cumulative survival rate of the implants was 95.0% at 10 years and 85.7% at 15 years. Of the 40 cases, excluding six cases of follow-up loss, 36 cases (90.0%) could be used without reoperation until death or at the last follow-up after surgery. Conclusion These results showed the outstanding functions of the knee and satisfactory long-term survivorship after UKA. Therefore, UKA could be a useful method for the treatment of osteoarthritis of the knee in elderly patients older than 70 years of age.

Purpose: The outcomes of non-trauma patients requiring intra-abdominal gauze packing for the management of uncontrollable hemorrhage following surgery, and the evaluation of survival risk factors were examined. Methods: Data from patients who underwent intra-abdominal gauze packing to control bleeding during abdominal surgery between September 2012 and March 2019 were retrospectively reviewed. Results: A total of 28 patients were included in the study population analysis. There were 9 patients who died during hospitalization. One patient died as a result of uncontrolled bleeding. In spite of gauze packing, 2 patients who had increasing blood transfusion requirements (> 4 packs/4 hours) were found to have arterial bleeding. Univariate analysis for hospital death showed that immunocompromised status, emergency surgery, a thrombocytopenic state prior to initial surgery, and a longer duration until gauze removal had a negative association with survival outcomes. Among these factors, only time to gauze removal > 36 hours was identified as an independent risk factor for survival outcome in the multivariate analysis. Conclusions Gauze packing could be considered as an effective method for the management of uncontrolled hemorrhage, in non-trauma patients. In cases of persistent bleeding after gauze packing, arterial bleeding should be suspected. Gauze removal after > 36 hours may indicate a poor survival outcome.

Background: Pedicle screw augmentation with bone cement has been experimentally demonstrated to increase the pullout strength. However, the mechanisms of screw loosening are complicated and interacting. Although vertebroplasty augmentation and fenestrated screw augmentation have been compared in many studies, there has been no comparative study on their clinical effects and complications in real clinical settings. We investigated clinical effects of bone cement augmentation of a pedicle screw and differences according to augmentation methods. Methods: Of the total 241 patients who had osteoporosis and underwent posterior pedicle screw fixation without anterior bone graft between January 2010 and December 2016, 132 patients with ≥2 years of radiological follow-up were included in this retrospective study. The patients were divided into group I (unaugmented) and group II (bone cement augmented). Group II was subdivided into II-S group (solid screw augmented) and II-F group (fenestrated screw augmented). The incidence of screw loosening was compared between groups I and II. Cement leakage, screw loosening, and screw fractures were investigated in the subgroups. Results: In total, 36 of 71 (52%, group I) unaugmented cases and 96 of 170 (56%, group II) augmented cases were followed up for ≥2 years. Of the total 78 solid screw augmented cases, 42 (56%) were in II-S group; 54 of the total 92 (59%) fenestrated screw augmented cases were in II-F group. Groups I and II were homogenous regarding demographic characteristics; II-S and II-F groups were also homogenous. The incidence of screw loosening was 50.0% (18/36) in group I and 7.3% (7/96) in group II (p < 0.001). Cement leakage developed in 2 of 42 (4.8%) cases in II-S group and in 5 of 54 (9.3%) cases in II-F group (p = 0.462). Screw loosening developed in 6 of 42 (14.3%) cases in II-S group and in 1 of 54 cases (1.9%) in II-F group (p = 0.041). Screw fracture developed in none of 42 cases in II-S group and in 3 of 54 cases (5.6%) in II-F group (p = 0.254). Conclusions In osteoporotic patients, bone cement augmentation of a pedicle screw decreased the incidence of screw loosening, and fenestrated screw augmentation was more effective than vertebroplasty augmentation.

Purpose: Isoform 2 of tight junction protein claudin-18 (CLDN18.2) is a potential target for gastric cancer treatment. A treatment targeting CLDN18.2 has shown promising results in gastric cancer. We investigated the clinical significance of CLDN18.2 and other cell-adherens junction molecules (Rho GTPase-activating protein [RhoGAP] and E-cadherin) in metastatic diffuse-type gastric cancer (mDGC). Materials and Methods: We evaluated CLDN18.2, RhoGAP, and E-cadherin expression using two-plex immunofluorescence and quantitative data analysis of H-scores of 77 consecutive mDGC patients who received first-line platinum-based chemotherapy between March 2015 and February 2017. Results: CLDN18.2 and E-cadherin expression was significantly lower in patients with peritoneal metastasis (PM) than those without PM at the time of diagnosis (P=0.010 and 0.013, respectively), whereas it was significantly higher in patients who never developed PM from diagnosis to death than in those who did (P=0.001 and 0.003, respectively). Meanwhile, CLDN18.2 and E-cadherin expression levels were significantly higher in patients with bone metastasis than in those without bone metastasis (P=0.010 and 0.001, respectively).Moreover, we identified a positive correlation between the expression of CLDN18.2 and E-cadherin (P<0.001), RhoGAP and CLDN18.2 (P=0.004), and RhoGAP and E-cadherin (P=0.001). Conversely, CLDN18.2, RhoGAP, and E-cadherin expression was not associated with chemotherapy response and survival. Conclusions CLDN18.2 expression was reduced in patients with PM but significantly intactin those with bone metastasis. Furthermore, CLDN18.2 expression was positively correlated with other adherens junction molecules, which is clinically associated with mDGC and PM pathogenesis.