Purpose: Radiotherapy is used to reduce the risk of breast cancer recurrence after surgery, but it is a potential cause of secondary cancer. We validated the risk of secondary cancer in primary breast cancer who received radiotherapy compared with those who did not from a matched cohort using a large-scale observational study of the Observational Health Data Sciences and Informatics (OHDSI) data network. Materials and Methods: A retrospective comparative cohort study using propensity score-matched cohorts was performed using two Observational Medical Outcome Partnership common data model databases, from tertiary general hospitals in South Korea. Among female patients who underwent surgery after the diagnosis of breast cancer, the risk of secondary primary malignant occurrence after 1:1 matching was analyzed. Results: Among 27,078 patients with breast cancer, there was no significant difference in the risk of secondary cancer following radiotherapy in 4,426 patients after 1:1 propensity-score matching. Further, there were no significant differences in the sensitivity analysis according to age, latency period, and number of radiation treatments. Conclusion There was no difference in the risk of secondary cancer in the patients diagnosed with breast cancer depending on whether or not radiotherapy was performed after surgery. In the future, it is necessary to analyze including data generated during cancer treatment.

Purpose: Radiotherapy (RT) remains a cornerstone of curative treatment for localized and locally advanced prostate cancer. However, dose escalation to improve tumor control is often constrained by the proximity of the rectum, which increases the risk of gastrointestinal (GI) and genitourinary toxicities. Biodegradable rectal spacers inserted between the prostate and rectum have emerged as an effective approach to reduce rectal radiation exposure. This guideline provides evidence-based recommendations on indications, contraindications, procedural standards, and clinical management for biodegradable rectal spacer insertion during prostate cancer RT. Materials and Methods: This guideline was developed by a multidisciplinary expert panel through a systematic review of the literature, analysis of international guidelines (National Comprehensive Cancer Network, European Association of Urology, American Society for Radiation Oncology), and expert consensus among radiation oncologists, radiologists, and urologists with clinical experience in spacer insertion. The strength of each recommendation and the level of evidence were classified according to the modified GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Results: Spacer insertion is conditionally recommended (Grade C, Level I) for patients receiving definitive external-beam RT without rectal invasion. It reduces the high-dose rectal irradiation volume (V70–75) by >50%, decreases acute GI toxicity, and helps maintain bowel-related quality of life. However, the benefit for late severe toxicity (grade 2 or higher) remains debated in recent meta-analyses. Contraindications include rectal invasion, anatomical inaccessibility, infection, and material hypersensitivity. Procedures should be performed under local anesthesia in a sterile environment by trained physicians. Short-course antibiotics and simulator-based training, including completion of multiple supervised cases, are advised. Conclusion Biodegradable rectal spacer insertion is clinically validated and effective in reducing acute rectal toxicity. Although pivotal trials demonstrated a favorable procedural safety profile, real-world postmarket data include reports of rare but severe procedural complications. This guideline provides standardized recommendations tailored to Korean clinical practice while remaining consistent with international standards, emphasizing the importance of operator training and careful patient selection.

Many neoplasms, including lung cancer, breast cancer, melanoma, and gastrointestinal tract malignancy, possess potential for skin metastasis. Skin metastases can represent the first presentation of such malignancies and may be observed incidentally during routine exam. Skin metastases from gastric adenocarcinoma are uncommon, with a prevalence rate of 0.04-0.8%. Cutaneous metastases from gastric cancer are generally observed as the initial symptom of advanced gastric cancer. Early detection and treatment can increase patient survival. A 42-year-old woman visited our department with nodule about 1 cm in size on the right frontal scalp noticed incidentally after laparoscopy-assisted distal gastrectomy and adjuvant systemic chemotherapy for early gastric cancer about 16 months prior. The patient was diagnosed with skin metastasis from gastric adenocarcinoma. Complete excision of the skin lesion and additional chemotherapy were performed. Herein, we report a case of nodular tumor-like scalp metastasis from early gastric cancer with a brief review of the literature.
Adenocarcinoma ; Adult ; Breast Neoplasms ; Drug Therapy ; Female ; Gastrectomy ; Gastrointestinal Tract ; Humans ; Lung Neoplasms ; Melanoma ; Neoplasm Metastasis* ; Prevalence ; Scalp* ; Skin ; Stomach Neoplasms*

Stem cells have attracted much attention due to their distinct features that support infinite self-renewal and differentiation into the cellular derivatives of three lineages. Recent studies have suggested that many stem cells both embryonic and adult stem cells reside in a specialized niche defined by hypoxic condition. In this respect, distinguishing functional differences arising from the oxygen concentration is important in understanding the nature of stem cells and in controlling stem cell fate for therapeutic purposes. ROS act as cellular signaling molecules involved in the propagation of signaling and the translation of environmental cues into cellular responses to maintain cellular homeostasis, which is mediated by the coordination of various cellular processes, and to adapt cellular activity to available bioenergetic sources. Thus, in this review, we describe the physiological role of ROS in stem cell fate and its effect on the metabolic regulation of stem cells.
Adult Stem Cells ; Cues ; Energy Metabolism ; Glucose ; Homeostasis ; Metabolism* ; Oxygen ; Reactive Oxygen Species ; Stem Cells*

The pneumonia severity index (PSI) and CURB-65 are widely used tools for the prediction of community-acquired pneumonia (CAP). This study was conducted to evaluate validation of severity scoring system including the PSI and CURB-65 scores of Korean CAP patients. In the prospective CAP cohort (participated in by 14 hospitals in Korea from January 2009 to September 2011), 883 patients aged over 18 yr were studied. The 30-day mortalities of all patients were calculated with their PSI index classes and CURB scores. The overall mortality rate was 4.5% (40/883). The mortality rates per CURB-65 score were as follows: score 0, 2.3% (6/260); score 1, 4.0% (12/300); score 2, 6.0% (13/216); score 3, 5.7% (5/88); score 4, 23.5% (4/17); and score 5, 0% (0/2). Mortality rate with PSI risk class were as follows: I, 2.3% (4/174); II, 2.7% (5/182); III, 2.3% (5/213); IV, 4.5% (11/245); and V, 21.7% (15/69). The subgroup mortality rate of Korean CAP patients varies based on the severity scores and CURB-65 is more valid for the lower scores, and PSI, for the higher scores. Thus, these variations must be considered when using PSI and CURB-65 for CAP in Korean patients.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Asian Continental Ancestry Group ; Cohort Studies ; Community-Acquired Infections/*mortality ; Female ; Humans ; Intensive Care Units ; Male ; Middle Aged ; Pneumonia/*mortality ; Prospective Studies ; Republic of Korea ; *Severity of Illness Index ; Young Adult

OBJECTIVE: To evaluate the depiction rate and morphologic features of myocardial bridging (MB) of the left anterior descending coronary artery (LAD) using dual-source CT (DSCT). MATERIALS AND METHODS: CT scans from a total of 1,353 patients who underwent DSCT were reviewed retrospectively for LAD-MB. Seventy-eight patients were excluded due to poor image quality or poor enhancement of the coronary artery. The length and depth of the MB were analyzed and classified as superficial or deep with respect to the depth (< or = 1 or > 1 mm) of the LAD tunneled segment. Superficial MB was subdivided into complete or incomplete types according to full or partial encasement of the myocardium. RESULTS: Of the 1,275 patients included in this study, 557 cases of MB were found from 536 patients (42%). Superficial MB was observed in 368 of 557 (66%) cases, and deep MB was seen in 189 of 557 (34%) cases. Superficial MB showed 2 types: complete (128 of 368, 35%) and incomplete (240 of 368, 65%). The mean length of a tunneled segment for superficial MB was 16.4 +/- 8.6 mm. The mean length and depth of a tunneled segment for deep MB were 27.6 +/- 12.8 mm and 3.0 +/- 1.4 mm, respectively. The incidence of atherosclerotic plaques in a 2-cm-long segment proximal to MB was 16%. CONCLUSION: The depiction rate of LAD-MB using DSCT in a large series of patients was 42%, with two-thirds of MB segments being the superficial type.
Contrast Media/diagnostic use ; Coronary Angiography/*methods ; Electrocardiography ; Female ; Humans ; Iohexol/analogs & derivatives/diagnostic use ; Male ; Middle Aged ; Myocardial Bridging/*radiography ; Radiographic Image Interpretation, Computer-Assisted ; Retrospective Studies ; Tomography, X-Ray Computed/*methods

The successful treatment of community-acquired pneumonia requires appropriate, empirical antimicrobial therapy. The etiology and antimicrobial susceptibility of major pneumonia pathogens can differ by country. Therefore, the ideal treatment guidelines for community-acquired pneumonia should be based on the studies performed in each country. We developed a treatment guideline for community-acquired pneumonia for immunocompetent adults in Korea. This guideline was developed by the joint committee of the Korean Society for Chemotherapy, the Korean Society of Infectious Diseases, and the Korean Academy of Tuberculosis and Respiratory diseases.
Adult ; Anti-Bacterial Agents ; Communicable Diseases ; Humans ; Joints ; Korea ; Pneumonia ; Tuberculosis

PURPOSE: Urethrocutaneous fistulas and urethral strictures are the most frequent complications after hypospadias repair. We reviewed outcomes after surgical repair of these complications to evaluate the factors determining successful outcome. MATERIALS AND METHODS: In 60 patients with fistula or stricture after hypospadias repair performed between September 1993 and January 2008, we reviewed incidences, clinical features, and outcome after repair with respect to initial hypospadias types. RESULTS: Fistulas were observed in 42 patients and were surgically repaired in 39 (92.8%). In 8 (19.0%) and 3 (7.1%) patients, concurrent meatal and urethral strictures were noted, respectively. The number of fistulas was single in 38 (90.5%) and 2 in 4 (9.5%) patients. Fistulas occurred most frequently from the penoscrotal type hypospadias (22/65, 33.8%) and had initially undergone transverse preputial island flap repair (13/26, 50%). Complete excision of the fistulous tract and multilayer advancement flap closure was the most common method for fistula repair (24), followed by cross-suture in 9 and repeat urethroplasty in 6. Initial management was successful in 35 (89.7%) patients. Urethral strictures were observed in 16 patients with equal incidences at the meatus and the other portion of the urethra. Successful outcome was achieved in all metal stenosis after repeat meatoplasty, whereas for urethral strictures, 4 (20%) patients who underwent visual urethrotomy experienced recurrent strictures. CONCLUSIONS: Urethrocutaneous fistulas can be successfully repaired by complete excision and cross-suture closure and multiple coverage with healthy tissues. In urethral strictures, reconstruction of ample neo-meatus is the key to achieving sufficient stream regardless of the stricture site.
Constriction, Pathologic ; Female ; Fistula ; Humans ; Hypospadias ; Incidence ; Male ; Rivers ; Urethra ; Urethral Obstruction ; Urethral Stricture

A successful therapy of community-acquired pneumonia requires appropriate empirical antimicrobial therapy. Etiology and antimicrobial susceptibility of major pathogens of pneumonia can differ by country. Therefore, an ideal treatment guideline of community-acquired pneumonia should be based on the studies performed in each country. We developed a treatment guideline for community-acquired pneumonia in immunocompetent adults in Korea. This guideline was developed by the joint committee of the Korean Society for Chemotherapy, the Korean Society of Infectious Diseases, and the Korean Academy of Tuberculosis and Respiratory diseases.
Adult ; Communicable Diseases ; Community-Acquired Infections ; Humans ; Joints ; Korea ; Pneumonia ; Tuberculosis

A successful therapy of community-acquired pneumonia requires appropriate empirical antimicrobial therapy. Etiology and antimicrobial susceptibility of major pathogens of pneumonia can differ by country. Therefore, an ideal treatment guideline of community-acquired pneumonia should be based on the studies performed in each country. We developed a treatment guideline for community-acquired pneumonia in immunocompetent adults in Korea. This guideline was developed by the joint committee of the Korean Society for Chemotherapy, the Korean Society of Infectious Diseases, and the Korean Academy of Tuberculosis and Respiratory diseases.
Adult ; Communicable Diseases ; Community-Acquired Infections ; Humans ; Joints ; Korea ; Pneumonia ; Tuberculosis