Purpose: Since 1995, the Korean Gastric Cancer Association (KGCA) has been periodically conducting nationwide surveys on patients with surgically treated gastric cancer. This study details the results of the survey conducted in 2023. Materials and Methods: The survey was conducted from March to December 2024 using a standardized case report form. Data were collected on 86 items, including patient demographics, tumor characteristics, surgical procedures, and surgical outcomes. The results of the 2023 survey were compared with those of previous surveys. Results: Data from 12,751 cases were collected from 66 institutions. The mean patient age was 64.6 years, and the proportion of patients aged ≥71 years increased from 9.1% in 1995 to 31.7% in 2023. The proportion of upper-third tumors slightly decreased to 16.8% compared to 20.9% in 2019. Early gastric cancer accounted for 63.1% of cases in 2023.Regarding operative procedures, a totally laparoscopic approach was most frequently applied (63.2%) in 2023, while robotic gastrectomy steadily increased to 9.5% from 2.1% in 2014.The most common anastomotic method was the Billroth II procedure (48.8%) after distal gastrectomy and double-tract reconstruction (51.9%) after proximal gastrectomy in 2023.However, the proportion of esophago-gastrostomy with anti-reflux procedures increased to 30.9%. The rates of post-operative mortality and overall complications were 1.0% and 15.3%, respectively. Conclusions The results of the 2023 nationwide survey demonstrate the current status of gastric cancer treatment in Korea. This information will provide a basis for future gastric cancer research.

Purpose: The opacity of zirconia sometimes requires a veneering material; thus lithium disilicate, a veneer material with excellent strength, can be used. This study investigated the fracture resistance of zirconia–lithium disilicate (Zr-LS2) bi-layered crowns according to the design of the substructure. Materials and Methods: Five groups of posterior Zr-LS2 restorations (Zirtooth and Amber LiSi-POZ) were fabricated with different zirconia substructure coverage (control group, groups half occlusal zirconia coverage; 1/2OZ, and three-quarter occlusal zirconia coverage; 3/4OZ) and margin designs (control group, groups collar margin; C-M, and collarless margin; Cl-M). All restorations were cemented with self-adhesive resin cement followed by 24-h water storage and thermocycling (10,000 cycles, 5°C and 55°C). The fracture load was measured, and failure mode analysis, fractography, and elemental analysis were performed. The one-way analysis of variance and Fisher’s exact test were performed for statistical analyses (α=.05). Results: A significant difference was found in the fracture load of Zr-LS2 restorations according to the zirconia coverage of the occlusal area and margin design (P<.05). Group 3/4OZ was significantly larger than the control group C and 1/2OZ (P<.05). The C-M group had greater fracture loads based on margin design than the control group C and Cl-M (P<.05). Conclusion The fracture resistance of posterior Zr-LS2 restorations increased with the zirconia coverage, occlusal thickness, and collar margin.

PURPOSE: The aim of this study was to evaluate the clinical performance and survival rate of implant-supported zirconia-lithium disilicate (Zr-LiSi) bilayered ceramic prostheses over 3 years. MATERIALS AND METHODS: This study included 71 patients, including 34 with implant-supported metal-ceramic prostheses (control group) and 37 with implant-supported Zr-LiSi bilayered ceramic prostheses (test group). The implant survival rate and incidence of prosthetic and biological complications (veneer fractures, dislodgement of screw-access hole filling material, screw loosening, peri-implant mucositis and peri-implantitis, and marginal bone loss) were investigated. The survival rate was analyzed using Kaplan-Meier survival curves, and the identity between two groups was confirmed by the log-rank test. RESULTS: Both groups showed a 100% survival rate, whereas the prosthetic survival rates were 77% and 73% for the metal-ceramic and Zr-LiSi groups, respectively. Biological complications did not appear in the metal-ceramic group, and 16.2% of peri-implant mucositis occurred in the Zr-LiSi group, which was significant (P < .05). Prosthetic complications occurred in 5.8% of the metal-ceramic group with veneer fractures and did not occur in the Zr-LiSi bilayered ceramic group. CONCLUSION This study revealed that posterior Zr-LiSi bilayered ceramic implant prostheses showed high survival rates and similar survival rates to metal-ceramic implant prostheses; however, additional consideration should be given to avoid overcontouring. Zr-LiSi bilayered ceramic implant prostheses may be an option for posterior implant-supported prosthetic treatment.

Patients with ectodermal dysplasia often have atrophied alveolar bone and an inadequate maxillomandibular relationship owing to congenital edentulism.Accurate implant placement that can overcomes anatomical limitations and orthognathic surgery to improve the maxillomandibular relationship is necessary for creating implant-supported prosthesis for these patients. Implant placement and provisional prosthesis fabrication before orthognathic surgery can provide critical fixed reference points and ensure accuracy during orthognathic surgery.In our patient, a digital system was used to design a surgical guide that considered the predictable position of the definitive prosthesis, allowing the placement of implants to overcome anatomical limitations and the creation of fixed reference points via the delivery of a provisional prosthesis for effective orthognathic surgery. The lack of compensation during orthognathic surgery was considered in the definitive prosthesis. As a result, a prosthesis with a minimal anterior cantilever was fabricated. This study aimed to determine the appropriate sequence of multidisciplinary collaborations that would, result in the best functional and aesthetic outcomes.

Purpose: Precise control of proliferation and differentiation of Leydig cells is important for gonadal androgenesis and spermatogenesis. Though cyclin-dependent kinase inhibitors are crucial for cell proliferation and differentiation, their role in the development of early adult Leydig cells (ALCs) remained unanswered. To understand mechanism for ALC development, functional expression of p57KIP2 (cdkn1c) was investigated in the stem Leydig cells (SLCs) and progenitor Leydig cells (PLCs) in mice. Materials and Methods: The roles of p57KIP2 in the proliferation, differentiation, apoptosis, and steroidogenesis in SLCs and PLCs were investigated by antibodies and bromodeoxyuridine (BrdU) labeling in the early neonatal testes and p57kip2 siRNA in the isolated SLCs and PLCs. Steroidogenic differentiation of PLCs was examined by progesterone and testosterone production in cell culture. Results: From postnatal day (PND) 1 to 14, p57KIP2(+) spindle-shaped cells in the testis interstitium were α-smooth muscle actin (αSMA)(-), a peritubular myoid cells marker, suggesting that they are SLCs and PLCs. Besides, p57KIP2 was also expressed in HSD3β(+) fetal Leydig cells. From PND1 to 14, BrdU(+)/αSMA(-), Ki67(+)/p57KIP2(+), and BrdU(+)/p57KIP2(+) spindle-shaped cells were gradually decreased. From PND1 to 14, p57KIP in the αSMA(-)/p57KIP2(+) cells was peaked at PND7 and decreased thereafter. In THY1(+) isolated SLCs, p57kip2 siRNA significantly increased ki67 and pcna mRNA and pdgfrα mRNA, a differentiation marker and decreased nestin mRNA, a SLC marker. No significant difference in apoptosis related genes mRNA was found after p57kip2 siRNA treatment. In HSD3β(+) PLCs, p57kip2 siRNA increased proapoptotic genes mRNA, annexin V(+) early-apoptotic cells. Importantly, p57kip2 siRNA significantly decreased hsd3β6 and cyp17a1 mRNA and progesterone production. Conclusions p57KIP2 may suppress proliferation and support stemness of SLCs. In PLCs, p57KIP2 may suppress apoptosis and potentiate the steroidogenic differentiation.

Purpose: The results of the TAILORx trial have shown that premenopausal patients with intermediate Oncotype Dx (ODx) recurrence score of 16–25 may benefit from adjuvant chemotherapy. In addition, the clinicopathological features showed the information complementary to ODx results. However, the characteristics may vary depending on menopausal status even in the same score. This study aimed to analyze the differences in the clinical characteristics by menopausal status. Methods: This study conducted a retrospective analysis of 756 patients with estrogen receptor-positive, human epidermal growth factor receptor 2-negative, and node-negative breast cancer who underwent the ODx test from July 2013 to December 2020 at the Severance Hospital. Results: Of the 756 patients, 261 patients were postmenopausal, and 495 were premenopausal. The premenopausal patients with a midrange ODx had similar clinicopathological features as compared to those with a high ODx. Conversely, the postmenopausal patients with a midrange ODx did not show significantly different clinicopathological features from those with a low ODx, whereas a difference was seen as compared to those with a high ODx. Conclusion In this study, unlike the postmenopausal patients, some of the clinicopathological characteristics of the premenopausal patients with a midrange ODx were closer to those with a high ODx than those with a low ODx. In the premenopausal patients with a midrange ODx, considering the baseline characteristic itself, there was a significant difference between those with a low ODx when compared with postmenopausal patients. Therefore, more aggressive treatment decisions may be helpful in premenopausal patients with a midrange ODx.

PURPOSE: The aim of this study was to evaluate the clinical performance and survival rate of implant-supported zirconia-lithium disilicate (Zr-LiSi) bilayered ceramic prostheses over 3 years. MATERIALS AND METHODS: This study included 71 patients, including 34 with implant-supported metal-ceramic prostheses (control group) and 37 with implant-supported Zr-LiSi bilayered ceramic prostheses (test group). The implant survival rate and incidence of prosthetic and biological complications (veneer fractures, dislodgement of screw-access hole filling material, screw loosening, peri-implant mucositis and peri-implantitis, and marginal bone loss) were investigated. The survival rate was analyzed using Kaplan-Meier survival curves, and the identity between two groups was confirmed by the log-rank test. RESULTS: Both groups showed a 100% survival rate, whereas the prosthetic survival rates were 77% and 73% for the metal-ceramic and Zr-LiSi groups, respectively. Biological complications did not appear in the metal-ceramic group, and 16.2% of peri-implant mucositis occurred in the Zr-LiSi group, which was significant (P < .05). Prosthetic complications occurred in 5.8% of the metal-ceramic group with veneer fractures and did not occur in the Zr-LiSi bilayered ceramic group. CONCLUSION This study revealed that posterior Zr-LiSi bilayered ceramic implant prostheses showed high survival rates and similar survival rates to metal-ceramic implant prostheses; however, additional consideration should be given to avoid overcontouring. Zr-LiSi bilayered ceramic implant prostheses may be an option for posterior implant-supported prosthetic treatment.

Patients with ectodermal dysplasia often have atrophied alveolar bone and an inadequate maxillomandibular relationship owing to congenital edentulism.Accurate implant placement that can overcomes anatomical limitations and orthognathic surgery to improve the maxillomandibular relationship is necessary for creating implant-supported prosthesis for these patients. Implant placement and provisional prosthesis fabrication before orthognathic surgery can provide critical fixed reference points and ensure accuracy during orthognathic surgery.In our patient, a digital system was used to design a surgical guide that considered the predictable position of the definitive prosthesis, allowing the placement of implants to overcome anatomical limitations and the creation of fixed reference points via the delivery of a provisional prosthesis for effective orthognathic surgery. The lack of compensation during orthognathic surgery was considered in the definitive prosthesis. As a result, a prosthesis with a minimal anterior cantilever was fabricated. This study aimed to determine the appropriate sequence of multidisciplinary collaborations that would, result in the best functional and aesthetic outcomes.

Purpose: Precise control of proliferation and differentiation of Leydig cells is important for gonadal androgenesis and spermatogenesis. Though cyclin-dependent kinase inhibitors are crucial for cell proliferation and differentiation, their role in the development of early adult Leydig cells (ALCs) remained unanswered. To understand mechanism for ALC development, functional expression of p57KIP2 (cdkn1c) was investigated in the stem Leydig cells (SLCs) and progenitor Leydig cells (PLCs) in mice. Materials and Methods: The roles of p57KIP2 in the proliferation, differentiation, apoptosis, and steroidogenesis in SLCs and PLCs were investigated by antibodies and bromodeoxyuridine (BrdU) labeling in the early neonatal testes and p57kip2 siRNA in the isolated SLCs and PLCs. Steroidogenic differentiation of PLCs was examined by progesterone and testosterone production in cell culture. Results: From postnatal day (PND) 1 to 14, p57KIP2(+) spindle-shaped cells in the testis interstitium were α-smooth muscle actin (αSMA)(-), a peritubular myoid cells marker, suggesting that they are SLCs and PLCs. Besides, p57KIP2 was also expressed in HSD3β(+) fetal Leydig cells. From PND1 to 14, BrdU(+)/αSMA(-), Ki67(+)/p57KIP2(+), and BrdU(+)/p57KIP2(+) spindle-shaped cells were gradually decreased. From PND1 to 14, p57KIP in the αSMA(-)/p57KIP2(+) cells was peaked at PND7 and decreased thereafter. In THY1(+) isolated SLCs, p57kip2 siRNA significantly increased ki67 and pcna mRNA and pdgfrα mRNA, a differentiation marker and decreased nestin mRNA, a SLC marker. No significant difference in apoptosis related genes mRNA was found after p57kip2 siRNA treatment. In HSD3β(+) PLCs, p57kip2 siRNA increased proapoptotic genes mRNA, annexin V(+) early-apoptotic cells. Importantly, p57kip2 siRNA significantly decreased hsd3β6 and cyp17a1 mRNA and progesterone production. Conclusions p57KIP2 may suppress proliferation and support stemness of SLCs. In PLCs, p57KIP2 may suppress apoptosis and potentiate the steroidogenic differentiation.