Background: Although various surface modifications enhance titanium (Ti) implant osseointegration, achieving rapid bone formation comparable to native healing remains challenging. Current strategies primarily focus on micro-scale topography, often overlooking the critical role of macroscopic three-dimensional (3D) architecture in osteoconduction. Methods: We hypothesized that mimicking native bone’s porous architecture is key to accelerating osseointegration. First, we verified the impact of structural continuity by comparing standard Ti implants with decellularized bone grafts in a mouse calvaria defect model. Subsequently, we developed a biomimetic polycaprolactone (PCL)-based 3D architectural cover (Cover-type) and evaluated its osseointegration efficacy in a rat femur model against conventional Ti implants. Results: The mouse study confirmed that decellularized bone integrated significantly faster than Ti, highlighting the necessity of 3D continuity. In the rat model, micro-computed tomography analysis indicated a clear trend of increased bone formation in the Cover-type group, though statistical significance was limited by sample size. However, histological analysis confirmed a statistically significant enhancement in bone-to-implant contact compared to controls (P<0.05). The PCL structure served as a scaffold for cell migration, effectively bridging the implant-bone gap. Conclusions These findings suggest that providing a bone-like 3D environment via a PCL cover may enhance histological osseointegration, rather than relying solely on surface chemistry.

Purpose: While the benefit of neoadjuvant chemotherapy (NAC) has been established in human epidermal growth factor receptor 2 (HER2)-positive and triple-negative breast cancers, its effectiveness in achieving pathological complete response (pCR) and optimal patient selection in estrogen receptor (ER)-positive, HER2-negative breast cancers remain less clearly defined. This study aimed to identify immunohistochemistry (IHC)-based predictors of pCR and to develop a scoring model for ER-strong positive/HER2-negative breast cancer. Methods: Data from a prospective cohort were retrospectively analyzed. We included 522 patients with ER-strong positive/HER2-negative tumors who received NAC and surgery between 2008 and 2021. IHC markers including progesterone receptor (PR), Ki-67, epidermal growth factor receptor (EGFR), cytokeratin 5/6 (CK5/6), and p53 were evaluated to identify predictors of pCR. Independent predictors of pCR from multivariate logistic regression were used to develop a weighted 4-point model. Model performance was assessed using receiver operating characteristic analysis. The prognostic impact of pCR was evaluated using KaplanMeier and Cox regression analyses. Results: Independent predictors of pCR included PR-negative status, positivity for basallike markers (EGFR or CK5/6), and Ki-67 ≥ 50%. The scoring model demonstrated good discrimination for pCR (area under the curve = 0.754). pCR rates increased stepwise, with scores of 4.9% (low), 10.7% (intermediate), and 36.2% (high). In the high-score group, pCR was significantly associated with improved disease-free survival (hazard ratio [HR], 0.09; p = 0.023) and distant metastasis-free survival (HR, 0.11; p = 0.035), whereas no significant survival differences according to pCR status were observed in the low and intermediate score groups. Conclusion This IHC-based model predicts pCR and helps identify subgroups in which pCR is associated with meaningful survival benefit following NAC in ER-positive/HER2-negative breast cancers. High-scoring patients may benefit from NAC, while patients with low- or intermediatescores may be better managed with surgery and endocrine therapy. This model may support personalized treatment decisions regarding NAC.

Purpose: Lobular carcinoma In Situ (LCIS) is a noninvasive lesion associated with an increased risk of invasive cancer. Since its removal from the tumor, node, metastasis classification in the 8th edition of the American Joint Committee on Cancer (AJCC) guidelines, the clinical management of LCIS has shifted from surgery to surveillance. However, studies focusing on the risk and associated factors for invasive cancer development in pure LCIS without ductal carcinoma In Situ (DCIS) or invasive cancer remain limited. Methods: We retrospectively analyzed 106 patients diagnosed with pure LCIS between 2008 and 2018. This study evaluated the effect of tamoxifen use and histologic type on the development of invasive cancer. Results: All 106 patients underwent surgery, and nine (8.5%) developed invasive cancer over a median follow-up of 67.5 months. The incidence of invasive cancer was lower in the tamoxifen group (6.3%, n = 4) than in the non-tamoxifen group (11.9%, n = 5), although this difference was not statistically significant (p = 0.266). Pleomorphic LCIS had a significantly higher incidence of invasive cancer (30.0%, n = 3) than classic LCIS (6.3%, n = 6) (p = 0.045).Multivariable Cox regression analysis showed no significant difference in the risk of invasive cancer according to tamoxifen use (hazard ratio [HR], 2.031; 95% confidence interval [CI], 0.544–7.579; p = 0.292). However, pleomorphic LCIS showed a trend toward an increased risk of invasive cancer compared to classic LCIS (HR, 3.856; 95% CI, 0.922–16.126; p = 0.064). Conclusion Postoperative tamoxifen did not significantly lower invasive cancer development in patients with pure LCIS. Pleomorphic LCIS may carry a higher risk than classic LCIS. These findings require tailored follow-up and treatment strategies based on the histologic subtype of LCIS.

Composite gangliocytomaeuroma and neuroendocrine tumors (CoGNETs) are extremely rare periampullary neoplasms composed of neuroendocrine epithelial, Schwannian spindle, and ganglion cells. Although endoscopic papillectomy or surgery have been used to treat ampullary CoGNETs, underwater endoscopic mucosal resection (UEMR) for periampullary lesions has not been previously described. In this study, we present a case of a 53-year-old man referred to our hospital with an incidentally detected subepithelial tumor in the second portion of the duodenum. Endoscopic ultrasound revealed a 13×10-mm homogeneous, hypoechoic, and well-demarcated submucosal mass. UEMR was performed under conscious sedation without submucosal injection, achieving safe en bloc resection within 12 min. Histopathology revealed a 2.0×1.5×1.2-cm lesion composed of mixed neuroendocrine epithelial, Schwannian spindle, and ganglion cells. Immunohistochemical staining was positive for chromogranin A, synaptophysin, CD56, neuron-specific enolase, and S-100, confirming CoGNET with a Ki-67 index of <1% and no lymphovascular or perineural invasion. Follow-up endoscopy 3 months later revealed only a post-resection scar without residual or recurrent tumors. This appears to be the first reported case of periampullary CoGNET successfully treated with UEMR. Therefore, UEMR might represent a safe and effective therapeutic option for selected periampullary subepithelial tumors.

Purpose: We aimed to evaluate the precision of preoperative colonoscopic tattooing and intraoperative colonoscopic tumor localization in determining distal surgical margins for leftsided colorectal cancer surgery. Methods: This retrospective study included 30 patients who underwent laparoscopic colorectal surgery, preoperative colonoscopic tattooing, and intraoperative colonoscopic localization for colorectal cancer at our center between July 2020 and March 2024. Clinical data were collected, and the precision of these methods was assessed by measuring the differences between the target resection margin and the actual pathological resection margin. Results: In four patient cases, the indocyanine green tattoo was not visible in the laparoscopic surgical field. The average stained length of the tattoo was 2.89 cm, with a mean distance of 1.18 cm between the low margin of the tattoo and the cancer. The difference between the target distal resection margin by intraoperative colonoscopic localization and the actual pathological resection margin was 0.88 cm. No complications related to the intraoperative colonoscopy were observed. Conclusion Preoperative tattooing showed limitations, such as spreading and occasional invisibility. Intraoperative colonoscopic localization proved to be an effective method for achieving more precise distal surgical margins in left-sided colorectal cancer surgery.

Purpose: We aimed to evaluate the precision of preoperative colonoscopic tattooing and intraoperative colonoscopic tumor localization in determining distal surgical margins for leftsided colorectal cancer surgery. Methods: This retrospective study included 30 patients who underwent laparoscopic colorectal surgery, preoperative colonoscopic tattooing, and intraoperative colonoscopic localization for colorectal cancer at our center between July 2020 and March 2024. Clinical data were collected, and the precision of these methods was assessed by measuring the differences between the target resection margin and the actual pathological resection margin. Results: In four patient cases, the indocyanine green tattoo was not visible in the laparoscopic surgical field. The average stained length of the tattoo was 2.89 cm, with a mean distance of 1.18 cm between the low margin of the tattoo and the cancer. The difference between the target distal resection margin by intraoperative colonoscopic localization and the actual pathological resection margin was 0.88 cm. No complications related to the intraoperative colonoscopy were observed. Conclusion Preoperative tattooing showed limitations, such as spreading and occasional invisibility. Intraoperative colonoscopic localization proved to be an effective method for achieving more precise distal surgical margins in left-sided colorectal cancer surgery.

Background/Aims: The clinical outcomes and optimal treatment of esophageal squamous cell carcinoma (ESCC) in elderly patients are unclear. This study aimed to assess the clinical outcomes of ESCC in patients aged ≥ 80 years. Methods: Medical records of patients diagnosed with ESCC between December 2008 and February 2024 were retrospectively reviewed. In total, 479 patients with ESCC were included and divided into the elderly (n = 52) and younger (n = 427) groups based on age. The clinical outcomes and survival rates, according to treatment, were compared between the two groups. Results: The median ages of the two groups were 82 years (range, 80–95 yr) and 66 years (41–79 yr). The overall survival was slightly lower in the elderly group; however, no statistical significance (hazard ratio [HR] 1.27, 95% confidence interval [CI] 0.85−1.91; p = 0.238) was observed. No differences were observed in the outcomes or survival between the two groups according to the treatment method (surgery, chemoradiotherapy or radiotherapy alone, and endoscopic resection). The elderly group was more likely to receive no treatment for cancer (30.8% vs. 13.6%, p = 0.002) than the younger group. However, when there was no treatment for cancer in the elderly group, survival was significantly lower than when treatment was administered (HR 0.08, 95% CI 0.03−020; p < 0.001). Conclusions In patients with ESCC aged ≥ 80 years, active cancer treatment was beneficial, and the results did not differ from those of younger patients.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Background/Aims: The incidence of steatotic liver disease (SLD) is increasing across all age groups as the incidence of obesity increases worldwide. The existing noninvasive prediction models for SLD require laboratory tests or imaging and perform poorly in the early diagnosis of infrequently screened populations such as young adults and individuals with healthcare disparities. We developed a machine learning-based point-of-care prediction model for SLD that is readily available to the broader population with the aim of facilitating early detection and timely intervention and ultimately reducing the burden of SLD. Methods: We retrospectively analyzed the clinical data of 28,506 adults who had routine health check-ups in South Korea from January to December 2022. A total of 229,162 individuals were included in the external validation study. Data were analyzed and predictions were made using a logistic regression model with machine learning algorithms. Results: A total of 20,094 individuals were categorized into SLD and non-SLD groups on the basis of the presence of fatty liver disease. We developed three prediction models: SLD model 1, which included age and body mass index (BMI); SLD model 2, which included BMI and body fat per muscle mass; and SLD model 3, which included BMI and visceral fat per muscle mass. In the derivation cohort, the area under the receiver operating characteristic curve (AUROC) was 0.817 for model 1, 0.821 for model 2, and 0.820 for model 3. In the internal validation cohort, 86.9% of individuals were correctly classified by the SLD models. The external validation study revealed an AUROC above 0.84 for all the models. Conclusions As our three novel SLD prediction models are cost-effective, noninvasive, and accessible, they could serve as validated clinical tools for mass screening of SLD.