Introduction of Multidisciplinary Team Approach for Head and Neck Cancer: Patient Satisfaction / 대한이비인후과학회지

Background and Objectives@#The head and neck multidisciplinary team (MDT) approach plays a crucial role in bringing together the ideas of various medical professionals. This study aimed to evaluate the early characteristics of the MDT approach for head and neck cancer and analyzed patients’ satisfaction.Subjects and Method We analyzed 450 head and neck cancer patients who received MDT care from August 2014 to June 2022. Patient satisfaction with MDT care was evaluated by selfadministered questionnaires consisting of 9 questions. @*Results@#Of 450, 298 (66.2%) were male and 152 (33.8%) were female. The mean age was 60.8±14.7 year. The most common primary site was the larynx (17.3%), followed by the oral cavity and oropharynx. A total of 726 cases of the MDT approach were performed in 266 MDT sessions, and the mean number of patients per MDT session was 2.74. The number of medical professionals participating in MDT ranged from a minimum of 3 to a maximum of 9, with a mean of 5.11. The mean running time of MDT meetings per case was 19.51 minutes. The time of the 2nd MDT was significantly shorter than that of the 1st or 3rd MDT. The mean score was close to very satisfactory in each of the 9 patient satisfaction questions. @*Conclusion@#We believe that the MDT approach is feasible and recommend its introduction for the treatment of head and neck cancer as most patients have shown very high satisfaction. Further studies on the role and efficacy of MDT care for head and neck cancer are necessary.

Medications and the Risk of Colorectal Cancer in Patients with Inflammatory Bowel Diseases:Use of the Landmark Method

Purpose@#This study aimed to determine whether the use of drugs in the treatment of inflammatory bowel disease is related to the risk of colorectal cancer using a Cox proportional hazards model with the landmark method to minimize immortal time bias. @*Materials and Methods@#This study was conducted as national cohort-based study using data from Korea’s Health Insurance Corporation. Newly diagnosed patients with inflammatory bowel disease from 2006 to 2010 were monitored for colorectal cancer until 2015. Hazard ratios and 95% confidence intervals were calculated and compared with the incidence of colorectal cancer with or without medications by applying various landmark points. @*Results@#In patients with Crohn’s disease, the prevention of colorectal cancer in the group exposed to immunomodulators was significant in the basic Cox model; however, the effect was not statistically significant in the model using the landmark method. The preventive effect of 5-aminosalicylic acid in patients with ulcerative colitis was significant in the basic and 6-month landmark point application models, but not in the remaining landmark application models. @*Conclusion@#In patients with inflammatory bowel disease, the preventive effect of drug exposure on colorectal cancer varies depending on the application of the landmark method. Hence, the possibility of immortal time bias should be considered.

Medications and the Risk of Colorectal Cancer in Patients with Inflammatory Bowel Diseases:Use of the Landmark Method

Purpose@#This study aimed to determine whether the use of drugs in the treatment of inflammatory bowel disease is related to the risk of colorectal cancer using a Cox proportional hazards model with the landmark method to minimize immortal time bias. @*Materials and Methods@#This study was conducted as national cohort-based study using data from Korea’s Health Insurance Corporation. Newly diagnosed patients with inflammatory bowel disease from 2006 to 2010 were monitored for colorectal cancer until 2015. Hazard ratios and 95% confidence intervals were calculated and compared with the incidence of colorectal cancer with or without medications by applying various landmark points. @*Results@#In patients with Crohn’s disease, the prevention of colorectal cancer in the group exposed to immunomodulators was significant in the basic Cox model; however, the effect was not statistically significant in the model using the landmark method. The preventive effect of 5-aminosalicylic acid in patients with ulcerative colitis was significant in the basic and 6-month landmark point application models, but not in the remaining landmark application models. @*Conclusion@#In patients with inflammatory bowel disease, the preventive effect of drug exposure on colorectal cancer varies depending on the application of the landmark method. Hence, the possibility of immortal time bias should be considered.

The Effectiveness of Postoperative Chemotherapyon pT1bN0 and pT2N0 Gastric Cancer Patients withRisk Factors: An International Dual-Center Analysis

Purpose@#This study aimed to investigate the effectiveness of postoperative chemotherapy in pT1bN0 and pT2N0 gastric cancer patients with high risk factors. @*Materials and Methods@#Clinicopathological data of gastric cancer patients, who had undergone gastrectomy in high volume centers in Korea and China and were finally diagnosed with pT1bN0 and pT2N0 between 2006 and 2010, were analyzed retrospectively. Survival analyses stratified by risk factors and multivariable analyses were performed. @*Results@#A total of 1509 patients were enrolled, with 41 (2.7%) patients receiving adjuvant chemotherapy after gastrectomy and 1468 (97.3%) patients undergoing surgery alone. The adjuvant chemotherapy group showed higher percentages of tumor with maximal diameter >3 cm (51.2% vs. 25.8%), poor differentiation (68.3% vs. 49.8%), and less harvested lymph nodes (17.1% vs. 5.2%) compared to the surgery alone group. The overall survival rates were 95.1% in the adjuvant chemotherapy group and 93.3% in the surgery alone group, without significant difference. In multivariable analysis, age was found to be an independent prognostic factor. However, there were no difference in the overall survival between patients with risk factors and those without risk factors, even in terms of age. Meanwhile, patients with more than two risk factors who received chemotherapy showed better survival trend, especially for pT2N0 patients, compared to the surgery alone group, although no significant differences were observed. @*Conclusion@#In pT1bN0 and pT2N0 patients, age was found to be an independent prognostic factor. However, adjuvant chemotherapy seemed to be unnecessary, while postoperative chemotherapy might offer survival benefits to pT2N0 patients with more than two risk factors.

Efficacy of non-surgical treatment accompanied by professional toothbrushing in the treatment of chronic periodontitis in patients with type 2 diabetes mellitus:a randomized controlled clinical trial

Purpose@#The present study aimed to evaluate the clinical benefit of additional toothbrushing accompanying non-surgical periodontal treatment on oral and general health in patients with type 2 diabetes mellitus (T2DM). @*Methods@#We conducted a doubled-blind randomized controlled trial in 60 T2DM patients between June 2013 and June 2014. The patients were randomly assigned to the scaling and root planing (SRP) group; the scaling and root planing with additional toothbrushing (SRPAT) group, in which additional toothbrushing was performed by toothpick methods; or the control group. Microbiological and oral examinations were performed for up to 12 weeks following treatment. Non-surgical treatment was conducted in the experimental groups. The SRP group received scaling and root planing and the SRPAT group received additional toothbrushing with the Watanabe method once a week from the first visit through the fifth visit. The primary outcomes were changes in haemoglobin A1c (or glycated haemoglobin; HbA1c) levels, serum endotoxin levels, and interleukin-1 beta levels. Periodontal health status was measured by periodontal pocket depth, the calculus index, and bleeding on probing (BOP). @*Results@#Both the SRP and SRPAT groups showed improvements in periodontal health and HbA1c, but the SRPAT group showed significantly less BOP than the SRP group. Furthermore, only the SRPAT group showed a statistically significant decrease in serum endotoxin levels. @*Conclusions@#Non-surgical periodontal treatment was effective in improving HbA1c and serum endotoxin levels in T2DM patients. Furthermore, non-surgical treatment with additional tooth brushing had a more favourable effect on gingival bleeding management.Trial RegistrationClinical Research Information Service Identifier: KCT000416

A Multi-cohort Study of the Prognostic Significance of Microsatellite Instability or Mismatch Repair Status after Recurrence of Resectable Gastric Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#High microsatellite instability (MSI) is related to good prognosis in gastric cancer. We aimed to identify the prognostic factors of patients with recurrent gastric cancer and investigate the role of MSI as a prognostic and predictive biomarker of survival after tumor recurrence. @*Materials and Methods@#This retrospective cohort study enrolled patients treated for stage II/III gastric cancer who developed tumor recurrence and in whom the MSI status or mismatch repair (MMR) status of the tumor was known. MSI status and the expression of MMR proteins were evaluated using polymerase chain reaction and immunohistochemical analysis, respectively. @*Results@#Of the 790 patients included, 64 (8.1%) had high MSI status or MMR deficiency. The tumor-node-metastasis stage, type of recurrence, Lauren classification, chemotherapy after recurrence, and interval to recurrence were independently associated with survival after tumor recurrence. The MSI/MMR status and receiving adjuvant chemotherapy were not associated with survival after recurrence. In a subgroup analysis of patients with high MSI or MMR-deficient gastric cancer, those who did not receive adjuvant chemotherapy had better treatment response to chemotherapy after recurrence than those who received adjuvant chemotherapy. @*Conclusion@#Patients with high MSI/MMR-deficient gastric cancer should be spared from adjuvant chemotherapy after surgery, but aggressive chemotherapy after recurrence should be considered. Higher tumor-node-metastasis stage, Lauren classification, interval to recurrence, and type of recurrence are associated with survival after tumor recurrence and should thus be considered when establishing a treatment plan and designing clinical trials targeting recurrent gastric cancer.

Prescription of antibiotics after tooth extraction in adults: a nationwide study in Korea

OBJECTIVES: This study aimed to understand the nationwide patterns of antibiotic prescription after tooth extraction in adult patients.MATERIALS AND METHODS: This study analyzed dental records from the National Health Insurance Service–National Sample Cohort (NHIS–NSC) database on 503,725 tooth extractions performed in adults (≥19 years) during 2011–2015. Patient sex, age, household income, systemic disease (diabetes mellitus and hypertension), type of dental institution, region of dental institution, year of prescription, and type of tooth extraction procedure were considered. The antibiotic prescription rate and broad-spectrum antibiotic prescription frequency were analyzed using chi-squared tests. Factors affecting the prescription of broad-spectrum antibiotics were evaluated using multivariate logistic regression analysis.RESULTS: The rate of antibiotic prescription after tooth extraction was 81.85%. Penicillin was most commonly prescribed (45.25%), followed by penicillin with beta-lactamase inhibitors (18.76%), metronidazole (12.29%), and second- to fourth-generation cephalosporins (11.52%). The proportion of broad-spectrum antibiotics used among all prescribed antibiotics was 45.88%.CONCLUSION: The findings of this study demonstrate that the rate of antibiotic prescription after tooth extraction is higher in Korea than in other countries. Furthermore, broad-spectrum antibiotics are used more frequently, which may indicate unnecessary drug prescription, an important contributor to antibiotic resistance.

Prescription of antibiotics after tooth extraction in adults: a nationwide study in Korea

OBJECTIVES@#This study aimed to understand the nationwide patterns of antibiotic prescription after tooth extraction in adult patients.@*MATERIALS AND METHODS@#This study analyzed dental records from the National Health Insurance Service–National Sample Cohort (NHIS–NSC) database on 503,725 tooth extractions performed in adults (≥19 years) during 2011–2015. Patient sex, age, household income, systemic disease (diabetes mellitus and hypertension), type of dental institution, region of dental institution, year of prescription, and type of tooth extraction procedure were considered. The antibiotic prescription rate and broad-spectrum antibiotic prescription frequency were analyzed using chi-squared tests. Factors affecting the prescription of broad-spectrum antibiotics were evaluated using multivariate logistic regression analysis.@*RESULTS@#The rate of antibiotic prescription after tooth extraction was 81.85%. Penicillin was most commonly prescribed (45.25%), followed by penicillin with beta-lactamase inhibitors (18.76%), metronidazole (12.29%), and second- to fourth-generation cephalosporins (11.52%). The proportion of broad-spectrum antibiotics used among all prescribed antibiotics was 45.88%.@*CONCLUSION@#The findings of this study demonstrate that the rate of antibiotic prescription after tooth extraction is higher in Korea than in other countries. Furthermore, broad-spectrum antibiotics are used more frequently, which may indicate unnecessary drug prescription, an important contributor to antibiotic resistance.

Prescription of antibiotics after tooth extraction in adults: a nationwide study in Korea

OBJECTIVES@#This study aimed to understand the nationwide patterns of antibiotic prescription after tooth extraction in adult patients.@*MATERIALS AND METHODS@#This study analyzed dental records from the National Health Insurance Service–National Sample Cohort (NHIS–NSC) database on 503,725 tooth extractions performed in adults (≥19 years) during 2011–2015. Patient sex, age, household income, systemic disease (diabetes mellitus and hypertension), type of dental institution, region of dental institution, year of prescription, and type of tooth extraction procedure were considered. The antibiotic prescription rate and broad-spectrum antibiotic prescription frequency were analyzed using chi-squared tests. Factors affecting the prescription of broad-spectrum antibiotics were evaluated using multivariate logistic regression analysis.@*RESULTS@#The rate of antibiotic prescription after tooth extraction was 81.85%. Penicillin was most commonly prescribed (45.25%), followed by penicillin with beta-lactamase inhibitors (18.76%), metronidazole (12.29%), and second- to fourth-generation cephalosporins (11.52%). The proportion of broad-spectrum antibiotics used among all prescribed antibiotics was 45.88%.@*CONCLUSION@#The findings of this study demonstrate that the rate of antibiotic prescription after tooth extraction is higher in Korea than in other countries. Furthermore, broad-spectrum antibiotics are used more frequently, which may indicate unnecessary drug prescription, an important contributor to antibiotic resistance.

Short-Term Outcomes of Intracorporeal Delta-Shaped Gastroduodenostomy Versus Extracorporeal Gastroduodenostomy after Laparoscopic Distal Gastrectomy for Gastric Cancer

BACKGROUND: Billroth I anastomosis is one of the most common reconstruction methods after distal gastrectomy for gastric cancer. Intracorporeal Billroth I (ICBI) anastomosis and extracorporeal Billroth I (ECBI) anastomosis are widely used in laparoscopic surgery. Here we compared ICBI and ECBI outcomes at a major gastric cancer center. METHODS: We retrospectively analyzed data from 2,284 gastric cancer patients who underwent laparoscopic distal gastrectomy between 2009 and 2017. We divided the subjects into ECBI (n=1,681) and ICBI (n=603) groups, compared the patients’ clinical characteristics and surgical and short-term outcomes, and performed risk factor analyses of postoperative complication development. RESULTS: The ICBI group experienced shorter operation times, less blood loss, and shorter hospital stays than the ECBI group. There were no clinically significant intergroup differences in diet initiation. Changes in white blood cell counts and C-reactive protein levels were similar between groups. Grade II–IV surgical complication rates were 2.7% and 4.0% in the ECBI and ICBI groups, respectively, with no significant intergroup differences. Male sex and a body mass index (BMI) ≥30 were independent risk factors for surgical complication development. In the ECBI group, patients with a BMI ≥30 experienced a significantly higher surgical complication rate than those with a lower BMI, while no such difference was observed in the ICBI group. CONCLUSION: The surgical safety of ICBI was similar to that of ECBI. Although the chosen anastomotic technique was not a risk factor for surgical complications, ECBI was more vulnerable to surgical complications than ICBI in patients with a high BMI (≥30).

Clinical Implications of Microsatellite Instability in Early Gastric Cancer

PURPOSE: We aimed to evaluate the clinical characteristics of microsatellite instability in early gastric cancer.MATERIALS AND METHODS: The microsatellite instability status of resected early gastric tumors was evaluated using two mononucleotide repeat markers (BAT25 and BAT26) and three dinucleotide repeat markers (D5S346, D2S123, and D17S250). Tumors with instability in two or more markers were defined as microsatellite instability-high (MSI-H) and others were classified as microsatellite stable (MSS).RESULTS: Overall, 1,156 tumors were included in the analysis, with 85 (7.4%) classified as MSI-H compared with MSS tumors. For MSI-H tumors, there was a significant correlation with the female sex, older age, tumor location in the lower gastric body, intestinal histology, lymphovascular invasion (LVI), and submucosal invasion (P<0.05). There was also a trend toward an association with lymph node (LN) metastasis (P=0.056). In mucosal gastric cancer, there was no significant difference in MSI status in tumors with LN metastasis or tumors with LVI. In submucosal gastric cancer, LVI was more frequently observed in MSI-H than in MSS tumors (38.9% vs. 25.0%, P=0.027), but there was no difference in the presence of LN metastases. The prognosis of MSI-H tumors was similar to that of MSS tumors (log-rank test, P=0.797, the hazard ratio for MSI-H was adjusted by age, sex, pT stage, and the number of metastatic LNs, 0.932; 95% confidence interval, 0.423–2.054; P=0.861).CONCLUSIONS: MSI status was not useful in predicting prognosis in early gastric cancer. However, the frequent presence of LVI in early MSI-H gastric cancer may help guide the appropriate treatment for patients, such as endoscopic treatment or limited LN surgical dissection.

Immunohistochemistry Biomarkers Predict Survival in Stage II/III Gastric Cancer Patients: From a Prospective Clinical Trial / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Identification of biomarkers to predict recurrence risk is essential to improve adjuvant treatment strategies in stage II/III gastric cancer patients. This study evaluated biomarkers for predicting survival after surgical resection. MATERIALS AND METHODS: This post-hoc analysis evaluated patients from the CLASSIC trial who underwent D2 gastrectomywith orwithout adjuvant chemotherapy (capecitabine plus oxaliplatin) at the Yonsei Cancer Center. Tumor expressions of thymidylate synthase (TS), excision repair cross-complementation group 1 (ERCC1), and programmed death-ligand 1 (PD-L1) were evaluated by immunohistochemical (IHC) staining to determine their predictive values. RESULTS: Among 139 patients, IHC analysis revealed high tumor expression of TS (n=22, 15.8%), ERCC1 (n=23, 16.5%), and PD-L1 (n=42, 30.2%) in the subset of patients. Among all patients, high TS expression tended to predict poor disease-free survival (DFS; hazard ratio [HR], 1.80; p=0.053), whereas PD-L1 positivity was associated with favorable DFS (HR, 0.33; p=0.001) and overall survival (OS; HR, 0.38; p=0.009) in multivariate Cox analysis. In the subgroup analysis, poor DFS was independently predicted by high TS expression (HR, 2.51; p=0.022) in the adjuvant chemotherapy subgroup (n=66). High PD-L1 expression was associated with favorable DFS (HR, 0.25; p=0.011) and OS (HR, 0.22; p=0.015) only in the surgery-alone subgroup (n=73). The prognostic impact of high ERCC1 expression was not significant in the multivariate Cox analysis. CONCLUSION: This study shows that high TS expression is a predictive factor for worse outcomes on capecitabine plus oxaliplatin adjuvant chemotherapy, whereas PD-L1 expression is a favorable prognostic factor in locally advanced gastric cancer patients.

Clinical Utility of Quantitative CT Analysis for Fissure Completeness in Bronchoscopic Lung Volume Reduction: Comparison between CT and Chartis™

OBJECTIVE: The absence of collateral ventilation (CV) is crucial for effective bronchoscopic lung volume reduction (BLVR) with an endobronchial valve. Here, we assessed whether CT can predict the Chartis™ results. MATERIALS AND METHODS: This study included 69 patients (mean age: 70.9 ± 6.6 years; 66 [95.7%] males) who had undergone CT to assess BLVR eligibility. The Chartis™ system (Pulmonox Inc.) was used to check CV. Experienced thoracic radiologists independently determined the completeness of fissures on volumetric CT images. RESULTS: The comparison between the visual and quantitative analyses revealed that 5% defect criterion showed good agreement. The Chartis™ assessment was performed for 129 lobes; 11 (19.6%) of 56 lobes with complete fissures on CT showed positive CV, while this rate was significantly higher (40 of 49 lobes, i.e., 81.6%) for lobes with incomplete fissures. The size of the fissure defect did not affect the rate of CV. Of the patients who underwent BLVR, 22 of 24 patients (91.7%) with complete fissures and three of four patients with incomplete fissures (75%) achieved target lobe volume reduction (TLVR). CONCLUSION: The quantitative analysis of fissure shows that incomplete fissures increased the probability of CV on Chartis™, while the defect size did not affect the overall rates. TLVR could be achieved even in some patients with relatively large fissure defect, if they showed negative CV on Chartis™.

Ten Thousand Consecutive Gastrectomies for Gastric Cancer: Perspectives of a Master Surgeon

As radical gastrectomy with lymph node dissection is currently the best strategy to cure gastric cancer, the role of the surgeon remains quite important in conquering it. Dr. Sung Hoon Noh, a surgeon and surgical oncologist specializing in gastric cancer, has treated gastric cancer for 30 years and has conducted over 10000 cases of gastrectomy for gastric cancer. He first adapted an electrocautery device into gastric cancer surgery and has led standardization of surgical procedures, including spleen preserving gastrectomy. His procedures based on patient-oriented insights have become the basis of the concept of enhanced recovery after surgery. He has also contributed to improving patient's survival through adoption of a multidisciplinary approach: he proved the benefit of adjuvant chemotherapy after radical D2 gastrectomy for stage II/III gastric cancer in clinical trials, updating treatment guidelines throughout the world. Dr. Noh also opened the era of precision medicine for treating gastric cancer, as he developed and validated a mRNA expression based algorithm to predict prognosis and response to chemotherapy. This article reviews his contribution and long history of service in the field of gastric cancer. The perspectives of this master surgeon, based on his profound experience and insights, will outline directions for integrative multidisciplinary health care and how can surgeons prepare for the future.

Single Patient Classifier Assay, Microsatellite Instability, and Epstein-Barr Virus Status Predict Clinical Outcomes in Stage II/III Gastric Cancer: Results from CLASSIC Trial

PURPOSE: Clinical implications of single patient classifier (SPC) and microsatellite instability (MSI) in stage II/III gastric cancer have been reported. We investigated SPC and the status of MSI and Epstein-Barr virus (EBV) as combinatory biomarkers to predict the prognosis and responsiveness of adjuvant chemotherapy for stage II/III gastric cancer. MATERIALS AND METHODS: Tumor specimens and clinical information were collected from patients enrolled in CLASSIC trial, a randomized controlled study of capecitabine plus oxaliplatin-based adjuvant chemotherapy. The results of nine-gene based SPC assay were classified as prognostication (SPC-prognosis) and prediction of chemotherapy benefit (SPC-prediction). Five quasimonomorphic mononucleotide markers were used to assess tumor MSI status. EBV-encoded small RNA in situ hybridization was performed to define EBV status. RESULTS: There were positive associations among SPC, MSI, and EBV statuses among 586 patients. In multivariate analysis of disease-free survival, SPC-prognosis [hazard ratio (HR): 1.879 (1.101–3.205), 2.399 (1.415–4.067), p=0.003] and MSI status (HR: 0.363, 95% confidence interval: 0.161–0.820, p=0.015) were independent prognostic factors along with age, Lauren classification, TNM stage, and chemotherapy. Patient survival of SPC-prognosis was well stratified regardless of EBV status and in microsatellite stable (MSS) group, but not in MSI-high group. Significant survival benefit from adjuvant chemotherapy was observed by SPC-Prediction in MSS and EBV-negative gastric cancer. CONCLUSION: SPC, MSI, and EBV statuses could be used in combination to predict the prognosis and responsiveness of adjuvant chemotherapy for stage II/III gastric cancer.

Modification of the TNM Staging System for Stage II/III Gastric Cancer Based on a Prognostic Single Patient Classifier Algorithm

PURPOSE: The modification of the cancer classification system aimed to improve the classical anatomy-based tumor, node, metastasis (TNM) staging by considering tumor biology, which is associated with patient prognosis, because such information provides additional precision and flexibility. MATERIALS AND METHODS: We previously developed an mRNA expression-based single patient classifier (SPC) algorithm that could predict the prognosis of patients with stage II/III gastric cancer. We also validated its utilization in clinical settings. The prognostic single patient classifier (pSPC) differentiates based on 3 prognostic groups (low-, intermediate-, and high-risk), and these groups were considered as independent prognostic factors along with TNM stages. We evaluated whether the modified TNM staging system based on the pSPC has a better prognostic performance than the TNM 8th edition staging system. The data of 652 patients who underwent gastrectomy with curative intent for gastric cancer between 2000 and 2004 were evaluated. Furthermore, 2 other cohorts (n=307 and 625) from a previous study were assessed. Thus, 1,584 patients were included in the analysis. To modify the TNM staging system, one-grade down-staging was applied to low-risk patients according to the pSPC in the TNM 8th edition staging system; for intermediate- and high-risk groups, the modified TNM and TNM 8th edition staging systems were identical. RESULTS: Among the 1,584 patients, 187 (11.8%), 664 (41.9%), and 733 (46.3%) were classified into the low-, intermediate-, and high-risk groups, respectively, according to the pSPC. pSPC prognoses and survival curves of the overall population were well stratified, and the TNM stage-adjusted hazard ratios of the intermediate- and high-risk groups were 1.96 (95% confidence interval [CI], 1.41–2.72; P < 0.001) and 2.54 (95% CI, 1.84–3.50; P < 0.001), respectively. Using Harrell's C-index, the prognostic performance of the modified TNM system was evaluated, and the results showed that its prognostic performance was better than that of the TNM 8th edition staging system in terms of overall survival (0.635 vs. 0.620, P < 0.001). CONCLUSIONS: The pSPC-modified TNM staging is an alternative staging system for stage II/III gastric cancer.

Eight to Ten Year Follow-Up Results of Total Knee Arthroplasty Using Electromagnetic Navigation System / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to compare the clinical and radiological results between patients who underwent total knee arthroplasty using the conventional method and the navigation-assisted method. MATERIALS AND METHODS: A retrospective review of was performed on 32 patients (40 knees) who underwent total knee arthroplasty between February 2004 and December 2006 and were followed-up for 8 to 10 years. Mechanical axis deviation, range of motion, radiologic position of the implants, and subjective clinical scores were measured and compared between 20 navigation-assisted total knee arthroplasties and 20 conventional total knee arthoplasties. Change in the values (α, β, γ, and δ angles) from the immediate postoperative period to the last follow-up were also calculated and compared between the two groups. RESULTS: The mean range of motion in the navigation group was improved to 121.8°±16.3° (92°–140°) at the last follow-up, and the Western Ontario McMaster Universities osteoarthritis Index (WOMAC) score was 89.8±5.4 and the Knee Society score (KSS) was 91.5±7.5. The mean range of motion in the conventional group was 112.6°±25.6° (60°–140°) at the last follow-up. The WOMAC score was 84.2±10.6, and the KSS was 81.1±14.3. The α, β, γ, and δ angles of the implants were not significantly changed until the last follow-up. In the comparison between the two groups, only the mean range of motion (p=0.018) and the KSS (p=0.038) showed statistically better results in the navigation group than the conventional group. CONCLUSION: Navigation-assisted total knee arthroplasty showed better KSS and range of motion compared with the conventional group in a cross-sectional study with 8 to 10 years of follow-up results. However, only the KSS showed a significant difference between the two groups by the amount of changes in the clinical and radiological results.

Colorimetric evaluation of white spot lesions following external bleaching with fluoridation: An in-vitro study / 대한치과교정학회지

OBJECTIVE: This study was performed to investigate the effects of external tooth bleaching with flouridation on the appearance of white spot lesions (WSLs) in vitro. METHODS: In total, 125 bracket-bonded bovine incisor enamel blocks with artificial WSLs were randomly divided into a control group and four treatment groups (home bleaching, home bleaching + fluoridation, in-office bleaching, and in-office bleaching + fluoridation). A spectroradiometer (SR) and digital images (DIs) were used to evaluate colorimetric parameters (Commission Internationale l'Eclairage L*a*b*) for all specimens. Color measurements were obtained before WSL formation (T1), after WSL formation (T2), and after completion of the external tooth bleaching treatment (T3). RESULTS: The SR-based color change after bleaching was significantly greater in the treatment groups than in the control group (p 0.05). CONCLUSIONS: The findings of this study suggested that external tooth bleaching with fluoridation can alleviate the conspicuity of WSLs.

Femoral Periprosthetic Fractures after Total Knee Arthroplasty: New Surgically Oriented Classification with a Review of Current Treatments

PURPOSE: As the number of total knee arthroplasties (TKAs) increases, the incidence of femoral periprosthetic fractures after TKA is also increasing. This review aimed to suggest a new surgically oriented classification system for femoral periprosthetic fractures. METHODS: We investigated the classifications, and current treatment trends for femoral periprosthetic fractures after TKA by means of a thorough review of the relevant literature. RESULTS: Numerous studies reported good results of surgical treatment with modern fixatives including locking compression plates and retrograde intramedullary nails. However, few classifications of femoral periprosthetic fractures reflect the recent developments in surgical treatment. CONCLUSIONS: We recommend that surgical management be considered the first-line treatment for femoral periprosthetic fractures after TKA. Our new classification will help in deciding the surgical treatment option for femoral periprosthetic fractures after TKA.

Combined Rotational Alignment Change after Total Knee Arthroplasty in Different Tibial Component Designs: Implications for Optimal Tibial Component Rotational Alignment

PURPOSE: The rotational alignment of the femoral and tibial components is closely related to the results after total knee arthroplasty (TKA). In this study, we measured the combined rotational alignment change (ΔCR) after TKA and compared the different influence of symmetric and asymmetric tibial component designs on the combined rotational alignment. MATERIALS AND METHODS: Eighty-four patients (mean age, 67.9 years) were included. A symmetric tibial component was used in 51 knees (group I), whereas an asymmetric tibial component was used in 50 knees (group II). We measured the angles of four anatomical landmarks by using preoperative and postoperative computed tomography images. The combined rotational alignment and the amount of change were calculated. The correlation between the isolated tibial component rotation (ITR) and ΔCR was analyzed by using the Spearman correlation coefficient. RESULTS: The mean ΔCR was −0.1°±6.3° in group I and −4.8°±5.7° in group II after TKA. Excluding the intercomponent rotation, the change was −1.0°±7.3° and −6.7°±6.7° in group I and group II, respectively. A correlation analysis between the ITR and tibial component rotation relative to the tibial tuberosity showed a statistically significant correlation. CONCLUSIONS: The combined lower limb rotational alignment was internally rotated in both symmetric and asymmetric tibial component designs after TKA. The asymmetric tibial component was better than the symmetric tibial component in achieving internally rotated combined lower limb rotational alignment. The internal rotation of the symmetric tibial component relative to the tibial tuberosity tip should fall within 20° to correct the externally deformed lower limb.