Purpose: High microsatellite instability (MSI) is related to good prognosis in gastric cancer. We aimed to identify the prognostic factors of patients with recurrent gastric cancer and investigate the role of MSI as a prognostic and predictive biomarker of survival after tumor recurrence. Materials and Methods: This retrospective cohort study enrolled patients treated for stage II/III gastric cancer who developed tumor recurrence and in whom the MSI status or mismatch repair (MMR) status of the tumor was known. MSI status and the expression of MMR proteins were evaluated using polymerase chain reaction and immunohistochemical analysis, respectively. Results: Of the 790 patients included, 64 (8.1%) had high MSI status or MMR deficiency. The tumor-node-metastasis stage, type of recurrence, Lauren classification, chemotherapy after recurrence, and interval to recurrence were independently associated with survival after tumor recurrence. The MSI/MMR status and receiving adjuvant chemotherapy were not associated with survival after recurrence. In a subgroup analysis of patients with high MSI or MMR-deficient gastric cancer, those who did not receive adjuvant chemotherapy had better treatment response to chemotherapy after recurrence than those who received adjuvant chemotherapy. Conclusion Patients with high MSI/MMR-deficient gastric cancer should be spared from adjuvant chemotherapy after surgery, but aggressive chemotherapy after recurrence should be considered. Higher tumor-node-metastasis stage, Lauren classification, interval to recurrence, and type of recurrence are associated with survival after tumor recurrence and should thus be considered when establishing a treatment plan and designing clinical trials targeting recurrent gastric cancer.

PURPOSE: We aimed to evaluate the clinical characteristics of microsatellite instability in early gastric cancer.MATERIALS AND METHODS: The microsatellite instability status of resected early gastric tumors was evaluated using two mononucleotide repeat markers (BAT25 and BAT26) and three dinucleotide repeat markers (D5S346, D2S123, and D17S250). Tumors with instability in two or more markers were defined as microsatellite instability-high (MSI-H) and others were classified as microsatellite stable (MSS).RESULTS: Overall, 1,156 tumors were included in the analysis, with 85 (7.4%) classified as MSI-H compared with MSS tumors. For MSI-H tumors, there was a significant correlation with the female sex, older age, tumor location in the lower gastric body, intestinal histology, lymphovascular invasion (LVI), and submucosal invasion (P<0.05). There was also a trend toward an association with lymph node (LN) metastasis (P=0.056). In mucosal gastric cancer, there was no significant difference in MSI status in tumors with LN metastasis or tumors with LVI. In submucosal gastric cancer, LVI was more frequently observed in MSI-H than in MSS tumors (38.9% vs. 25.0%, P=0.027), but there was no difference in the presence of LN metastases. The prognosis of MSI-H tumors was similar to that of MSS tumors (log-rank test, P=0.797, the hazard ratio for MSI-H was adjusted by age, sex, pT stage, and the number of metastatic LNs, 0.932; 95% confidence interval, 0.423–2.054; P=0.861).CONCLUSIONS: MSI status was not useful in predicting prognosis in early gastric cancer. However, the frequent presence of LVI in early MSI-H gastric cancer may help guide the appropriate treatment for patients, such as endoscopic treatment or limited LN surgical dissection.
Dinucleotide Repeats ; Female ; Humans ; Lymph Nodes ; Microsatellite Instability ; Microsatellite Repeats ; Neoplasm Metastasis ; Prognosis ; Stomach Neoplasms

OBJECTIVES: The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status. METHODS: Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results. RESULTS: The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis. CONCLUSIONS: The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.
Asymptomatic Infections ; Coronavirus ; Coronavirus Infections* ; Cross Infection ; Delivery of Health Care ; Epidemiology ; Fluorescent Antibody Technique ; Humans ; Hypertension ; Inpatients ; Korea* ; Middle East Respiratory Syndrome Coronavirus* ; Middle East* ; Osteoarthritis

OBJECTIVES: The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status.METHODS: Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results.RESULTS: The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis.CONCLUSIONS: The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.
Asymptomatic Infections ; Coronavirus ; Coronavirus Infections ; Cross Infection ; Delivery of Health Care ; Epidemiology ; Fluorescent Antibody Technique ; Humans ; Hypertension ; Inpatients ; Korea ; Middle East Respiratory Syndrome Coronavirus ; Middle East ; Osteoarthritis

OBJECTIVES: The rates of asymptomatic infection with Middle East Respiratory Syndrome (MERS) coronavirus vary. A serologic study was conducted to determine the asymptomatic MERS infection rate in healthcare workers and non-healthcare workers by exposure status. METHODS: Study participants were selected from contacts of MERS patients based on a priority system in 4 regions strongly affected by the 2015 MERS outbreak. A sero-epidemiological survey was performed in 1,610 contacts (average duration from exposure to test, 4.8 months), and the collected sera were tested using an enzyme-linked immunespecific assay (ELISA), immunofluorescence assay (IFA), and plaque reduction neutralization antibody test (PRNT). Among the 1,610 contacts, there were 7 ELISA-positive cases, of which 1 exhibited positive IFA and PRNT results. RESULTS: The asymptomatic infection rate was 0.060% (95% confidence interval, 0.002 to 0.346). The asymptomatic MERS case was a patient who had been hospitalized with patient zero on the same floor of the hospital at the same time. The case was quarantined at home for 2 weeks after discharge, and had underlying diseases, including hypertension, angina, and degenerative arthritis. CONCLUSIONS The asymptomatic infection was acquired via healthcare-associated transmission. Thus, it is necessary to extend serologic studies to include inpatient contacts who have no symptoms.

Nephronophthisis-related ciliopathy (NPHP-RC) is a common genetic cause of end-stage renal failure during childhood and adolescence and exhibits an autosomal recessive pattern of inheritance. Genetic diagnosis is quite limited owing to genetic heterogeneity in NPHP-RC. We designed a novel approach involving the step-wise screening of Sanger sequencing and targeted exome sequencing for the genetic diagnosis of 55 patients with NPHP-RC. First, five NPHP-RC genes were analyzed by Sanger sequencing in phenotypically classified patients. Known pathogenic mutations were identified in 12 patients (21.8%); homozygous deletions of NPHP1 in 4 juvenile nephronophthisis patients, IQCB1/NPHP5 mutations in 3 Senior–Løken syndrome patients, a CEP290/NPHP6 mutation in 1 Joubert syndrome patient, and TMEM67/MKS3 mutations in 4 Joubert syndrome patients with liver involvement. In the remaining undiagnosed patients, we applied targeted exome sequencing of 34 ciliopathy-related genes to detect known pathogenic mutations in 7 (16.3%) of 43 patients. Another 18 likely damaging heterozygous variants were identified in 13 NPHP-RC genes in 18 patients. In this study, we report a variety of pathogenic and candidate mutations identified in 55 patients with NPHP-RC in Korea using a step-wise application of two genetic tests. These results support the clinical utility of targeted exome sequencing to resolve the issue of allelic and genetic heterogeneity in NPHP-RC.
Adolescent ; Diagnosis* ; Exome* ; Genetic Heterogeneity* ; Humans ; Kidney Failure, Chronic ; Korea ; Liver ; Mass Screening ; Wills

East Asian surgeons generally report lower morbidity and mortality rates for gastrectomy with D2 lymphadenectomy than do surgeons in Western countries; however, the disparity remains unexplained. The aim of this article was to determine the feasibility and safety regarding cases in which East Asian surgeons perform such procedures in Caucasian patients (CPs). Twelve CPs underwent gastrectomy with lymphadenectomy for gastric cancer at Yonsei University Severance Hospital, Seoul, Korea between June 2011 and April 2014. Procedures performed included total gastrectomy (7 of 12, 58%), distal gastrectomy (4 of 12, 33%), and completion total gastrectomy (1 of 12, 8%). Nine patients (75%) underwent D2 lymphadenectomy, and D1+ lymphadenectomy was performed in three others (25%). In four patients (33%), combined resections were carried out. The median values of surgical parameters were as follows: operative time, 266.5 min (range, 120-586 min); estimated blood loss, 90 mL (range, 37-350 mL); retrieved lymph node count, 37.5 (range, 22-63); and postoperative hospital stay, 13.7 days (range, 5-63 days). No mortality was encountered, although two patients (17%) experienced complications (both Clavien-Dindo classification grade IIIa anastomotic leakages), which were successfully managed by conservative treatment. In the hands of East Asian surgeons, mortality and short-term morbidity appears to be acceptably low in CPs subjected to gastrectomy with lymphadenectomy for gastric cancer.
Adult ; Aged ; *European Continental Ancestry Group ; Female ; *Gastrectomy/adverse effects ; Humans ; Length of Stay ; *Lymph Node Excision/adverse effects ; Male ; Middle Aged ; Operative Time ; *Patients ; Pilot Projects ; Republic of Korea ; Safety ; Stomach Neoplasms/pathology/*surgery ; *Surgeons

OBJECTIVEThe aim of this review was to overview the current practice of gastric cancer treatment including surgery and other adjuvant modalities.

DATA SOURCESThe review was based on data obtained from the published articles and main guidelines in the East and West.

STUDY SELECTIONArticles with high level of evidence or current best evidence in each issue were selected to be reviewed.

RESULTSAlthough varied adjuvant modalities have been proved to be benefit for treating gastric cancer, surgery is still the most important treatment strategy against gastric cancer. Actively adapting to new technology is important but it should be balanced with an effort to establish sound scientific rationale that adheres to oncologic principles.

CONCLUSIONSFuture treatment of gastric cancer will be focused on tailored, personalized therapy. For achieving it, collaboration across disciplines is essential. Also the philosophy of caring for the patients with gastric cancer should be rooted in the realization of true patient benefit regardless of who is providing the care. With these philosophies, we can shift the scientific and technological advances toward triumph over gastric cancer.

PURPOSE: Although neoadjuvant therapy has been accepted as a treatment option in locally-advanced gastric cancer, its prognostic value has been difficult to evaluate. MATERIALS AND METHODS: Seventy-four gastric cancer patients who underwent gastrectomy after neoadjuvant treatment were divided into two groups according to the pathologic response: favorable (ypT0) and others (ypT1-4). The clinicopathologic characteristics, predictive factors for pathologic response, and oncologic outcome were evaluated. RESULTS: Eleven patients (14.8%) demonstrated ypT0 and the remaining 63 patients (85.2%) were ypT1-4. Chemoradiotherapy (CCRTx) rather than chemotherapy (CTx) was the only predictive factor for a favorable pathologic response. Chemotherapeutic factors and tumor marker levels did not predict pathologic response. The 1-, 2-, and 3-year disease-free survivals were 83.4%, 70%, and 52.2%. The 1-, 3-, 5-year overall survivals were 88.5%, 67.5%, and 51.2%, respectively. Although a complete pathologic response (ypT0N0M0) was achieved in 7 patients, 28.6% of them demonstrated recurrence of the tumor within 6 months after curative surgery. CONCLUSION: CCRTx rather than CTx appears to be more effective for achieving good pathologic response. Although favorable pathologic response has been achieved after neoadjuvant treatment, the survival benefit remains controversial.
Aged ; Chemoradiotherapy/*methods ; Disease-Free Survival ; Female ; Gastrectomy ; Humans ; Male ; Middle Aged ; Neoadjuvant Therapy ; Neoplasm Recurrence, Local/pathology ; Stomach Neoplasms/*drug therapy/mortality/pathology/*radiotherapy/surgery ; Treatment Outcome ; Tumor Markers, Biological

PURPOSE: Medullary sponge kidney (MSK) is a rare congenital disease characterized by diffuse ectasia or dilatation of precalyceal collecting tubules. MSK incidence and prevalence in the general population is uncertain and only a few patients are reported especially in the pediatric age. There has been increasing reports of patients with MSK who have other malformative disorders. Also several case reports concerning about etiological association of some genes. METHODS: Collaborative study through nation-wide survey was done to investigate the incidence and etiological association of some genes such as GDNF gene, ATP6V1B1, ATP6V0A4 gene in developing MSK in Korean children. RESULTS: Four cases of MSK who have various other malformative disorders were collected. There are no mutations of GDNF gene, ATP6V1B1, ATP6V0A4 gene in all patients. CONCLUSION: MSK is one of the very rare diseases in pediatric age. The etiological association of GDNF gene , ATP6V1B1, ATP6V0A4 gene in developing MSK in Korean children is not proved.
Child ; Dilatation ; Dilatation, Pathologic ; Glial Cell Line-Derived Neurotrophic Factor ; Humans ; Incidence ; Medullary Sponge Kidney ; Prevalence ; Rare Diseases