Purpose: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Materials and Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Purpose: Although human epidermal growth factor receptor 2 (HER2) positivity is prevalent in microinvasive breast cancer (MIBC), data focused on HER2-positive MIBC are limited. We investigated the clinical course and long-term outcomes of HER2-positive MIBC and evaluated the role of adjuvant chemotherapy. Materials and Methods: The study included patients with curatively resected pT1mi pN0 HER2-positive breast cancer between January 2000 and January 2020. Treatments and survival outcomes, including invasive breast cancer-free survival (IBCFS), distant recurrence-free survival (DRFS), and overall survival (OS) were analyzed. Results: The analysis included 799 female patients. The median age was 51 years (range, 23 to 79 years), and 51.6% (n=412) were premenopausal. Multifocality was confirmed in 17.3% (n=138), and estrogen receptor (ER) positivity in 29.8% (n=238). Adjuvant chemotherapy was administered to 17.5% (n=140), with doxifluridine in 96.4% of cases. One patient (0.1%) received trastuzumab. With a median follow-up of 119.0 months (95% confidence interval [CI], 114.0 to 127.0), the 8-year IBCFS, DRFS, and OS were 91.2% (95% CI, 89.1 to 93.3), 97.5% (95% CI, 96.4 to 98.7), and 98.8% (95% CI, 98.0 to 99.6), respectively. No significant differences were observed between patients with and without adjuvant chemotherapy. The lack of differences in IBCFS by chemotherapy was consistent across subgroups, including pre-/postmenopausal patients, grade 1-2/3 tumors, and ER-negative disease. Conclusion A clinically meaningful proportion of HER2-positive MIBC patients experience IBCFS events with long-term follow-up. Adjuvant chemotherapy did not improve survival, potentially due to the use of an outdated, ineffective regimen. The role of modern adjuvant regimens, particularly those incorporating HER2-targeted therapy, warrants further exploration.

Background/Aims: Biliary tract cancer (BTC) is a rare malignancy with poor prognosis. We investigated genomic determinants of clinical benefit from gemcitabine, cisplatin, and nab-paclitaxel (GAP) versus gemcitabine and cisplatin (GC) in advanced BTC. Methods: Clinical and genomic data using TruSight Oncology 500 were analyzed from patients treated with GAP (N=198) or GC (N=89) as first-line therapy. Results: With a median follow-up of 33.0 months, GAP modestly improved progression-free survival (PFS) (hazard ratio [HR] 0.764; 95% confidence interval [CI] 0.591–0.989) without significant overall survival (OS) difference compared to GC. Genomic profiling revealed frequent alterations in TP53 (35.2%), KRAS (16.4%), SMAD4 (10.5%), and TNFRSF14 (10.5%), involving RTK/RAS (44.3%), TP53 (41.8%), and PI3K (20.2%) pathways. Single-gene mutations did not predict treatment benefit. However, pathway-level analysis identified PI3K pathway activation as significantly associated with inferior PFS (HR 2.148; 95% CI 1.478–3.124) and OS (HR 2.096; 95% CI 1.413–3.109) in patients receiving GAP, an effect not observed with GC. Importantly, GAP conferred clinical benefit only in patients without PI3K pathway activation, while no survival advantage was seen in those with such alterations (Pinteraction=0.023 for PFS, Pinteraction=0.003 for OS). Similar results were obtained in the independent validation cohort treated with GAP (N=103) or GC (N=64) for BTC. Conclusions Genomic profiling using next-generation sequencing identified PI3K pathway activation as key molecular determinant that differentiates patient outcomes between GAP and GC treatments in advanced BTC.

Background: Dual energy X-ray absorptiometry (DXA) measurements vary among instruments from different manufacturers. This study aimed to assess the correlation between bone mineral density (BMD) and body composition measured by the GE Lunar Prodigy and Hologic Horizon W DXA systems and to develop conversion equations. Methods: A total of 120 healthy volunteers (59 males, 61 females) aged 20 to 70 years were scanned on both DXA systems on the same day. BMD was measured at the lumbar spine (L1-L4) and bilateral femurs. Body composition parameters were measured for the whole body and regional sites. Bland-Altman analysis, Pearson correlation, and concordance correlation coefficient (CCC) were used to assess agreement. Linear regression was performed to derive conversion equations. Results: The Hologic system measured BMD values 14% to 20% lower at the lumbar spine and 8% to 17% lower at femoral sites compared to the GE Lunar system (all P<0.0001). Lean mass values were 4% to 10% lower on the Hologic system. Very strong correlations were observed for both BMD (r=0.944-0.980) and lean mass (r=0.963-0.984). Cross-calibration equations were developed for all measurement sites. Conclusions Despite significant systematic differences, there was very high correlation between the two DXA systems. The conversion equations can facilitate comparison of measurements between these systems in clinical practice and research.

Purpose: Based on the KEYNOTE-522 study, neoadjuvant pembrolizumab plus chemotherapy has become the standard treatment for early-stage triple-negative breast cancer (TNBC).This study evaluated the real-world efficacy, safety, and predictors of pathologic complete response (pCR) in Korean patients. Methods: We conducted a retrospective cohort study of 174 patients with early-stage TNBC who received the KEYNOTE-522 regimen (neoadjuvant pembrolizumab plus paclitaxel and carboplatin, followed by doxorubicin and cyclophosphamide) at a tertiary cancer center between August 2022 and July 2024. We assessed the primary endpoints, including pCR rate and event-free survival (EFS). We performed univariable and multivariable logistic regression analyses to identify independent predictors of pCR. Results: The median patient age was 50 years (range, 24–74 years). The clinical stages were II and III in 79.3% and 20.1% of patients, respectively, and 10.9% had clinical N3 disease. The overall pCR rate was 62.1%, and the N3 subgroup had a pCR rate of 47.4%. On multivariable analysis, high baseline Ki-67 expression (≥ median, 75%) was significantly associated with pCR (odds ratio, 2.84; 95% confidence interval, 1.45 to 5.66; p = 0.002). At a median followup of 18.4 months, the 12-month EFS rate was 97.4%, with significantly superior outcomes observed in patients who achieved pCR compared with those who did not achieve pCR (100% vs. 93.1%, p = 0.007). The treatment completion rate was 92.0%, and immune-related adverse events occurred in 13.8% of patients. Conclusion In this real-world analysis of one of the largest Asian cohorts of patients with earlystage TNBC treated with neoadjuvant pembrolizumab, the KEYNOTE-522 regimen demonstrated substantial efficacy and manageable toxicity, consistent with the original trial findings.

Objectives: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes. Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5460 ESD cases from 5250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

This study aimed to evaluate the long-term efficacy and complication of radiotherapy for benign soft tissue tumors. Five cases of benign soft tissue tumors (two plexiform neurofibromas, two juvenile nasopharyngeal angiofibromas, and one cavernous sinus hemangioma) who underwent radiotherapy were enrolled. All patients had at least 10 years of follow-up. The median follow-up duration was 12 years (range, 10 to 27). Three patients underwent incomplete excision prior to radiotherapy. Radiation doses were either 54 Gy in 30 fractions or 50.4 Gy in 28 fractions (1.8 Gy per fraction). Every patient achieved complete remission (CR) or near-CR. The tumor volume decreased significantly within the first 2 years of follow-up and continued to decrease slowly up to 10 years; no distinct further decrease in tumor volume was observed after 10 years. One patient developed left mandibular hypoplasia 8 years after radiotherapy. Significant volume decrease was achievable within a few years after radiotherapy in benign soft tissue tumors. Therefore, radiotherapy is a viable option for unresectable or incompletely resected benign soft tissue tumors with a minimum risk of complication.

Background: s/Aims: Hepatocellular carcinoma (HCC) is a malignant cancer with an increasing incidence worldwide. Although numerous efforts have been made to identify effective therapies for HCC, current strategies have limitations. We present a new approach for targeting L-arginine and argininosuccinate synthetase 1 (ASS1). Methods: ASS1 expression in HCC cell lines and primary hepatocytes was detected using polymerase chain reaction and western blotting. Proliferation, migration, signaling pathways, and nitric oxide production in HCC cell lines were measured using MTS, colony formation, wound healing, Western blot, and Griess assays. Results: ASS1 expression varied among the HCC cell lines, and cisplatin cytotoxicity was ASS1-dependent. L-arginine alone induced apoptosis in HCC cell lines, regardless of ASS1 expression; however, its effect was enhanced in ASS1-expressing HCC cell lines. Cisplatin cytotoxicity also increased, suggesting that L-arginine acts as a sensitizer to cisplatin in HCC cell lines. ASS1 and L-arginine produced nitric oxide and inhibited key proliferation- and survival-related signaling pathways such as PI3K/Akt and MAPK. Additionally, ASS1 and L-arginine reduced the expression of PKM1 and PKM2 in the glycolysis pathway. Conclusions Our study revealed that ASS1 and L-arginine exhibited anticancer effects in HCC and sensitized cisplatin-resistant HCC cells to chemotherapy. The combination of ASS1 and L-arginine significantly enhanced the anticancer effects, even in HCC cell lines with low or absent ASS1 expression. These findings highlight the critical roles of arginine and ASS1 in HCC and suggest that increasing arginine availability could be a promising therapeutic strategy.

This study aimed to evaluate the long-term efficacy and complication of radiotherapy for benign soft tissue tumors. Five cases of benign soft tissue tumors (two plexiform neurofibromas, two juvenile nasopharyngeal angiofibromas, and one cavernous sinus hemangioma) who underwent radiotherapy were enrolled. All patients had at least 10 years of follow-up. The median follow-up duration was 12 years (range, 10 to 27). Three patients underwent incomplete excision prior to radiotherapy. Radiation doses were either 54 Gy in 30 fractions or 50.4 Gy in 28 fractions (1.8 Gy per fraction). Every patient achieved complete remission (CR) or near-CR. The tumor volume decreased significantly within the first 2 years of follow-up and continued to decrease slowly up to 10 years; no distinct further decrease in tumor volume was observed after 10 years. One patient developed left mandibular hypoplasia 8 years after radiotherapy. Significant volume decrease was achievable within a few years after radiotherapy in benign soft tissue tumors. Therefore, radiotherapy is a viable option for unresectable or incompletely resected benign soft tissue tumors with a minimum risk of complication.