Background: The taxonomic status of house mice (Mus musculus) on the Korean Peninsula has long been debated due to conflicting morphological classifications and limited genetic evidence. Historically, three subspecies (M. m.molossinus, M. m. utsuryonis, and M. m. yamashinai) have been proposed based on external traits, although the validity of these proposals remains uncertain. Thus, this study aimed to integrate genetic and morphological analyses to clarify the phylogenetic relationships of Korean mice relative to the well-known primary M. musculus subspecies and evaluate the taxonomic distinctiveness. Results: Genetic analysis of mitochondrial DNA (cytb gene) from mice across Korea, including islands, mountains, and agricultural fields, confirmed that these mice belong to the Eurasian M. m. musculus lineage. Morphologically, Korean mice exhibited tail ratios consistent with previously assigned subspecies, suggesting these traits represent intraspecific variation within M. m. musculus. Craniometric analyses revealed distinctive features, such as a shorter, narrower premaxillary tooth-patch width and a longer maxillary tooth-row length, thereby distinguishing these mice from laboratory strains derived from M. m. domesticus. These cranial configurations, visualized via three-dimensional micro-computed tomography scans, further supported the morphological divergence of these mice from other subspecies. Conclusions Our findings indicate that Korean house mice belong to a single subspecific group within M. m.musculus, with observed morphological variations reflecting local adaptation rather than distinct taxonomic divisions.The Korean Peninsula likely served as an ecological bridge, facilitating the spatiotemporal diversification of M. m.musculus across East Eurasia. This study resolves longstanding taxonomic ambiguities and underscores the subspecific status of Korean house mice within M. m. musculus. These insights provide a foundation for understanding the biogeographic history of human commensal species and future biomedical research utilizing wild-derived mouse models.

Purpose: The aim of this study is to compare the detection ability of quality of life (QoL) changes and responsiveness of the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS)-40 and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ). Materials and Methods: A multicenter prospective observational study was conducted to evaluate QoL changes after various gastrectomies between January 2021 and April 2022. Participants were instructed to complete the KOQUSS-40 and EORTC QLQ-C30/STO22 preoperatively and at 1, 3, 6, and 12 months postoperatively. QoL changes over time and QoL responsiveness were assessed for each questionnaire. Results: Data from 491 patients who underwent curative gastrectomy for gastric cancer at 22 institutions were analyzed. The summary scores of the KOQUSS-40 and EORTC QLQ-STO22 showed significant differences between the total and proximal gastrectomy groups (p=0.044 and p=0.038, respectively), but no difference was observed for the EORTC QLQ-C30. Dysphagia on the KOQUSS-40 was significantly different between the total and proximal gastrectomy groups (p=0.031); however, dysphagia on the EORTC QLQ-STO22 did not differ. The responsiveness of the KOQUSS-40 was similar to that of the EORTC QLQ in patients who experienced ≥ 10% body weight loss, but approximately 10% less in patients receiving adjuvant chemotherapy than the EORTC QLQ. Conclusion KOQUSS-40 has several advantages over EORTC QLQ-C30/STO22 when comparing QoL between the total and proximal gastrectomy groups. The findings provide information for researchers investigating the QoL of patients who have undergone curative gastrectomy for gastric cancer.

Purpose: The male predominance in the incidence of gastric cancer (GC) is established; however, sex differences in the prognosis of GC remain controversial. As such, this study analyzed the prognosis of patients with GC based on age and sex. Materials and Methods: Data from 14,739 patients diagnosed with GC at Seoul National University Bundang Hospital between 2003 and 2023 were analyzed. Baseline characteristics, histological types of GC, overall and GC-specific survival rates (age and stage stratification), and associated risk factors were analyzed. Results: Females were significantly younger (p < 0.001) and exhibited more gastric body cancers (p < 0.001) and tumors with diffuse-type or poorly differentiated histology (p < 0.001) than males. Females exhibited an advantage over males in terms of overall survival (p=0.004), but not in GC-specific survival. However, age stratification revealed significant sex differences, that females < 50 years of age exhibited survival disadvantages (p < 0.001); however, this trend was reversed with age, and females > 60 years exhibited survival advantages (p < 0.001) for both overall and GC-specific survival. This may be explained by the lower ratio of diffuse-type GC as females age. Furthermore, in the analysis according to stage, females with stage IV disease exhibited significant survival disadvantages, with significantly younger age and a higher proportion of diffuse-type GC which exhibits aggressive features, resulting in poorer survival than in males. Conclusion Age and stage stratification revealed significant differences in survival between the sexes, which can be helpful for public health strategies.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

Purpose: This study evaluated the postoperative quality of life (QoL) after various types of gastrectomy for gastric cancer. Materials and Methods: A multicenter prospective observational study was conducted in Korea using the Korean Quality of Life in Stomach Cancer Patients Study (KOQUSS)-40, a new QoL assessment tool focusing on postgastrectomy syndrome. Overall, 496 patients with gastric cancer were enrolled, and QoL was assessed at 5 time points: preoperatively and at 1, 3, 6, and 12 months after surgery. Results: Distal gastrectomy (DG) and pylorus-preserving gastrectomy (PPG) showed significantly better outcomes than total gastrectomy (TG) and proximal gastrectomy (PG) with regard to total score, indigestion, and dysphagia. DG, PPG, and TG also showed significantly better outcomes than PG in terms of dumping syndrome and worry about cancer. Postoperative QoL did not differ significantly according to anastomosis type in DG, except for Billroth I anastomosis, which achieved better bowel habit change scores than the others. No domains differed significantly when comparing double tract reconstruction and esophagogastrostomy after PG. The total QoL score correlated significantly with postoperative body weight loss (more than 10%) and extent of resection (P<0.05 for both).Reflux as assessed by KOQUSS-40 did not correlate significantly with reflux observed on gastroscopy 1 year postoperatively (P=0.064). Conclusions Our prospective observation using KOQUSS-40 revealed that DG and PPG lead to better QoL than TG and PG. Further study is needed to compare postoperative QoL according to anastomosis type in DG and PG.

Purpose: GC1118 is a novel antibody targeting epidermal growth factor receptor (EGFR) with enhanced blocking activity against both low- and high-affinity EGFR ligands. A phase 1b/2a study was conducted to determine a recommended phase 2 dose (RP2D) of GC1118 in combination with 5-fluorouracil, leucovorin, and irinotecan (FOLFIRI) (phase 1b) and to assess the safety and efficacy of GC1118 plus FOLFIRI as a second-line therapy for recurrent/metastatic colorectal cancer (CRC) (phase 2a). Materials and Methods: Phase 1b was designed as a standard 3+3 dose-escalation study with a starting dose of GC1118 (3 mg/kg/week) in combination with biweekly FOLFIRI (irinotecan 180 mg/m2; leucovorin 400 mg/m2; 5-fluorouracil 400 mg/m2 bolus and 2,400 mg/m2 infusion over 46 hours) in patients with solid tumors refractory to standard treatments. The subsequent phase 2a part was conducted with objective response rate (ORR) as a primary endpoint. Patients with KRAS/NRAS/BRAF wild-type, EGFR-positive, recurrent/metastatic CRC resistant to the first-line treatment were enrolled in the phase 2a study. Results: RP2D of GC1118 was determined to be 3 mg/kg/wk in the phase 1b study (n=7). Common adverse drug reactions (ADRs) observed in the phase 2a study (n=24) were acneiform rash (95.8%), dry skin (66.7%), paronychia (58.3%), and stomatitis (50.0%). The most common ADR of ≥ grade 3 was neutropenia (33.3%). ORR was 42.5% (95% confidence interval [CI], 23.5 to 62.0), and median progression-free survival was 6.7 months (95% CI, 4.0-8.0). Conclusion GC1118 administered weekly at 3 mg/kg in combination with FOLFIRI appears as an effective and safe treatment option in recurrent/metastatic CRC.

Purpose: Bone metastasis (BM) adversely affects the prognosis of gastric cancer (GC). We investigated molecular features and immune microenvironment that characterize GC with BM compared to GC without BM. Materials and Methods: Targeted DNA and whole transcriptome sequencing were performed using formalin-fixed paraffin-embedded primary tumor tissues (gastrectomy specimens) of 50 GC cases with distant metastases (14 with BM and 36 without BM). In addition, immunohistochemistry (IHC) for mucin-12 and multiplex IHC for immune cell markers were performed. Results: Most GC cases with BM had a histologic type of poorly cohesive carcinoma and showed worse overall survival (OS) than GC without BM (p < 0.05). GC with BM tended to have higher mutation rates in TP53, KDR, APC, KDM5A, and RHOA than GC without BM. Chief cell-enriched genes (PGA3, PGC, and LIPF), MUC12, MFSD4A, TSPAN7, and TRIM50 were upregulated in GC with BM compared to GC without BM, which was correlated with poor OS (p < 0.05). However, the expression of SERPINA6, SLC30A2, PMAIP1, and ITIH2 were downregulated in GC with BM. GC with BM was associated with PIK3/AKT/mTOR pathway activation, whereas GC without BM showed the opposite effect. The densities of helper, cytotoxic, and regulatory T cells did not differ between the two groups, whereas the densities of macrophages were lower in GC with BM (p < 0.05). Conclusion GC with BM had different gene mutation and expression profiles than GC without BM, and had more genetic alterations associated with a poor prognosis.

Background: The etiology and pathology of mucoid degeneration of the anterior cruciate ligament (MD-ACL) remain poorly understood. MD-ACL may be associated with knee osteoarthritis (OA) or a mechanism other than OA. This study evaluated the radiological differences between knees with MD-ACL and those with a normal ACL and compared the clinical and radiological features of knees with MD-ACL according to the knee OA status. Methods: This retrospective study compared the radiological features of the intercondylar notch width index (NWI) and posterior tibial slope (PTS) of 67 MD-ACL patients (MD group) and 67 age-, sex-, and OA grade-matched patients with a normal ACL (control group). During the subgroup analysis, MD-ACL patients were divided into the non-OA subgroup (n = 41) and OA subgroup (n = 26). The pain location and characteristics of the knee, PTS, and NWI were compared between these subgroups. Results: Compared to the control group, the MD group had a lower NWI (0.26 ± 0.03 vs. 0.28 ± 0.01, p < 0.001) and a larger PTS (11.3° ± 3.0° vs. 9.2° ± 2.5°, p < 0.001). During the subgroup analysis, the most common pain locations were the posterior and medial aspects of the knee in the non-OA subgroup (43.9%) and OA subgroup (53.8%), respectively. Pain on terminal flexion was the most common pain characteristic in both subgroups (non-OA subgroup, 73.1%; OA subgroup, 53.8%). The PTS was not different between subgroups (11.7° ± 3.2° in the non-OA subgroup vs. 10.6° ± 2.7° in the OA subgroup; p = 0.159). However, the non-OA subgroup had a lower NWI than the OA subgroup (0.25 ± 0.03 vs. 0.28 ± 0.02, p = 0.001). Conclusions Patients with MD-ACL had a lower NWI and a larger PTS than patients with a normal ACL. Furthermore, the clinical and radiological features of MD-ACL differed according to the knee OA status. A narrow intercondylar notch may be more closely associated with the development of MD-ACL without OA.

Background/Aims: Synchronous multiple gastric cancer (SMGC) accounts for approximately 6% to 14% of gastric cancer (GC) cases. This study aimed to identify risk factors for SMGC. Methods: A total of 14,603 patients diagnosed with GC were prospectively enrolled. Data including age, sex, body mass index, smoking, alcohol consumption, family history, p53 expression, microsatellite instability, cancer classification, lymph node metastasis, and treatment were collected. Risk factors were analyzed using logistic regression analysis between a single GC and SMGC. Results: The incidence of SMGC was 4.04%, and that of early GC (EGC) and advanced GC (AGC) was 5.43% and 3.11%, respectively. Patients with SMGC were older (65.33 years vs 61.75 years, p<0.001) and more likely to be male. Lymph node metastasis was found in 27% of patients with SMGC and 32% of patients with single GC. Multivariate analysis showed that SMGC was associated with sex (male odds ratio [OR], 1.669; 95% confidence interval [CI], 1.223 to 2.278; p=0.001), age (≥65 years OR, 1.532; 95% CI, 1.169 to 2.008; p=0.002), and EGC (OR, 1.929; 95% CI, 1.432 to 2.600; p<0.001). Survival rates were affected by Lauren classification, sex, tumor size, cancer type, distant metastasis, and venous invasion but were not related to the number of GCs. However, the survival rate of AGC with SMGC was very high. Conclusions SMGC had unique characteristics such as male sex, older age, and EGC, and the survival rate of AGC, in which the intestinal type was much more frequent, was very good (Trial registration number: NCT04973631).