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.

Background: Epidermal growth factor receptor (EGFR) gene mutation testing is crucial for the administration of tyrosine kinase inhibitors to treat non–small cell lung cancer. In addition to traditional tissue-based tests, liquid biopsies using plasma are increasingly utilized, particularly for detecting T790M mutations. This study compared tissue- and plasma-based EGFR testing methods. Methods: A total of 248 patients were tested for EGFR mutations using tissue and plasma samples from 2018 to 2023 at Pusan National University Yangsan Hospital. Tissue tests were performed using PANAmutyper, and plasma tests were performed using the Cobas EGFR Mutation Test v2. Results: All 248 patients underwent tissue-based EGFR testing, and 245 (98.8%) showed positive results. Of the 408 plasma tests, 237 (58.1%) were positive. For the T790M mutation, tissue biopsies were performed 87 times in 69 patients, and 30 positive cases (38.6%) were detected. Plasma testing for the T790M mutation was conducted 333 times in 207 patients, yielding 62 positive results (18.6%). Of these, 57 (27.5%) were confirmed to have the mutation via plasma testing. Combined tissue and plasma tests for the T790M mutation were positive in nine patients (13.4%), while 17 (25.4%) were positive in tissue only and 12 (17.9%) in plasma only. This mutation was not detected in 28 patients (43.3%). Conclusions Although the tissue- and plasma-based tests showed a sensitivity of 37.3% and 32.8%, respectively, combined testing increased the detection rate to 56.7%. Thus, neither test demonstrated superiority, rather, they were complementary.

Purpose: To analyze prognostic factors for morphological and functional recovery after vitrectomy in patients with idiopathic epiretinal membrane (ERM). Methods: We conducted a retrospective analysis of patients with ERM who underwent vitrectomy. Postoperative outcomes were evaluated in terms of functional and morphological changes, assessing best-corrected visual acuity (BCVA) and central macular thickness (CMT) after 6 months. Logistic regression was used to identify factors influencing postoperative outcomes. Results: This study included 77 patients (35.1% men). Thirty-eight patients underwent combined vitrectomy and cataract surgery. Logistic regression revealed that better preoperative BCVA was associated with improved postoperative BCVA (p = 0.002). Among the 38 eyes that underwent combined surgery, longer preoperative axial length was linked to better visual outcomes in univariate analysis (p = 0.043), although the association was not statistically significant in multivariate analysis (p = 0.064). Younger age and thinner preoperative CMT were associated with better morphological outcomes (p = 0.034 and p = 0.001, respectively). Conclusions Preoperative BCVA, age, preoperative CMT, and axial length are predictive factors for functional and morphological outcomes after vitrectomy in patients with ERM. These findings may facilitate treatment planning and prognosis prediction before surgery.

Background: Epidermal growth factor receptor (EGFR) gene mutation testing is crucial for the administration of tyrosine kinase inhibitors to treat non–small cell lung cancer. In addition to traditional tissue-based tests, liquid biopsies using plasma are increasingly utilized, particularly for detecting T790M mutations. This study compared tissue- and plasma-based EGFR testing methods. Methods: A total of 248 patients were tested for EGFR mutations using tissue and plasma samples from 2018 to 2023 at Pusan National University Yangsan Hospital. Tissue tests were performed using PANAmutyper, and plasma tests were performed using the Cobas EGFR Mutation Test v2. Results: All 248 patients underwent tissue-based EGFR testing, and 245 (98.8%) showed positive results. Of the 408 plasma tests, 237 (58.1%) were positive. For the T790M mutation, tissue biopsies were performed 87 times in 69 patients, and 30 positive cases (38.6%) were detected. Plasma testing for the T790M mutation was conducted 333 times in 207 patients, yielding 62 positive results (18.6%). Of these, 57 (27.5%) were confirmed to have the mutation via plasma testing. Combined tissue and plasma tests for the T790M mutation were positive in nine patients (13.4%), while 17 (25.4%) were positive in tissue only and 12 (17.9%) in plasma only. This mutation was not detected in 28 patients (43.3%). Conclusions Although the tissue- and plasma-based tests showed a sensitivity of 37.3% and 32.8%, respectively, combined testing increased the detection rate to 56.7%. Thus, neither test demonstrated superiority, rather, they were complementary.

Purpose: To analyze prognostic factors for morphological and functional recovery after vitrectomy in patients with idiopathic epiretinal membrane (ERM). Methods: We conducted a retrospective analysis of patients with ERM who underwent vitrectomy. Postoperative outcomes were evaluated in terms of functional and morphological changes, assessing best-corrected visual acuity (BCVA) and central macular thickness (CMT) after 6 months. Logistic regression was used to identify factors influencing postoperative outcomes. Results: This study included 77 patients (35.1% men). Thirty-eight patients underwent combined vitrectomy and cataract surgery. Logistic regression revealed that better preoperative BCVA was associated with improved postoperative BCVA (p = 0.002). Among the 38 eyes that underwent combined surgery, longer preoperative axial length was linked to better visual outcomes in univariate analysis (p = 0.043), although the association was not statistically significant in multivariate analysis (p = 0.064). Younger age and thinner preoperative CMT were associated with better morphological outcomes (p = 0.034 and p = 0.001, respectively). Conclusions Preoperative BCVA, age, preoperative CMT, and axial length are predictive factors for functional and morphological outcomes after vitrectomy in patients with ERM. These findings may facilitate treatment planning and prognosis prediction before surgery.

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.