Clinical Practice Patterns of Hypertensive Disease in Pregnancy among Korean Obstetricians

Purpose@#The purpose of this study was to investigate the clinical practice patterns of Korean obstetricians and gynecologists the diagnosis and management of hypertensive disease in pregnant women. @*Methods@#From April 2015 to October 2015, questionnaire was distributed via email to obstetricians who were members of the Society for Maternal and Fetal Medicine. The survey consisted of 37 questions in 6 categories. Responses to the questions on the management of hypertensive disorders of pregnancy, from diagnosis to treatment, were evaluated. @*Results@#A total of 93 obstetricians and gynecologists responded to the survey. High blood pressure was allocated the highest priority as an index mainly used when deciding to hospitalize patients with hypertensive disease during pregnancy, followed by pregnancy symptoms, proteinuria, and blood test results. Calcium channel blocker (CCB) for oral administration and hydralazine for injection were preferred as antihypertensive drugs mainly used to control severe hypertension. Regarding the delivery method for hypertensive disease during pregnancy, in cases of preeclampsia, 63% of the respondents chose the delivery method according to the cervical status, and in cases of hemolysis, elevated liver enzymes and low platelets (HELLP) syndrome and eclampsia, which increased in severity, 52% and 31% responded that the delivery method was determined according to the cervical status, respectively. In cases of mild preeclampsia, the 70% of respondents preferred 37–38 weeks of gestation for the delivery time. Regarding the use of aspirin in patient with hypertension during pregnancy, 52% of the respondents occasionally administered aspirin, and in patients with a history of hypertensive disease during pregnancy, only 43% were administered prophylactic aspirin. @*Conclusion@#Domestic obstetricians regarded blood pressure as the most meaningful factor when treating women with hypertension during pregnancy and considered blood pressure control as important. The preferred antihypertensive agents were oral CCB and hydralazine injections, and the choice of delivery method was determined according to the condition of the cervix and severity of the disease. Even in women with high risk factors for preeclampsia, prophylactic aspirin was administered in as low as 50%, of patients, possibly may due to the absence of domestic guidelines for aspirin use during pregnancy. Korean guidelines for prophylactic aspirin administration during pregnancy is needed based on additional research on the efficacy of aspirin for domestic women in the future.

Clinical Practice Patterns of Hypertensive Disease in Pregnancy among Korean Obstetricians

Purpose@#The purpose of this study was to investigate the clinical practice patterns of Korean obstetricians and gynecologists the diagnosis and management of hypertensive disease in pregnant women. @*Methods@#From April 2015 to October 2015, questionnaire was distributed via email to obstetricians who were members of the Society for Maternal and Fetal Medicine. The survey consisted of 37 questions in 6 categories. Responses to the questions on the management of hypertensive disorders of pregnancy, from diagnosis to treatment, were evaluated. @*Results@#A total of 93 obstetricians and gynecologists responded to the survey. High blood pressure was allocated the highest priority as an index mainly used when deciding to hospitalize patients with hypertensive disease during pregnancy, followed by pregnancy symptoms, proteinuria, and blood test results. Calcium channel blocker (CCB) for oral administration and hydralazine for injection were preferred as antihypertensive drugs mainly used to control severe hypertension. Regarding the delivery method for hypertensive disease during pregnancy, in cases of preeclampsia, 63% of the respondents chose the delivery method according to the cervical status, and in cases of hemolysis, elevated liver enzymes and low platelets (HELLP) syndrome and eclampsia, which increased in severity, 52% and 31% responded that the delivery method was determined according to the cervical status, respectively. In cases of mild preeclampsia, the 70% of respondents preferred 37–38 weeks of gestation for the delivery time. Regarding the use of aspirin in patient with hypertension during pregnancy, 52% of the respondents occasionally administered aspirin, and in patients with a history of hypertensive disease during pregnancy, only 43% were administered prophylactic aspirin. @*Conclusion@#Domestic obstetricians regarded blood pressure as the most meaningful factor when treating women with hypertension during pregnancy and considered blood pressure control as important. The preferred antihypertensive agents were oral CCB and hydralazine injections, and the choice of delivery method was determined according to the condition of the cervix and severity of the disease. Even in women with high risk factors for preeclampsia, prophylactic aspirin was administered in as low as 50%, of patients, possibly may due to the absence of domestic guidelines for aspirin use during pregnancy. Korean guidelines for prophylactic aspirin administration during pregnancy is needed based on additional research on the efficacy of aspirin for domestic women in the future.

Degenerative joint disease in the temporomandibular joint with fibrous ankylosis in a rhesus macaque (Macaca mulatta) / 한국실험동물학회지

Background@#Ankylosis in the temporomandibular joint (TMJ) is known to have various etiologies in veterinary medicine. We observed a case of fibrous ankylosis of the TMJ in a newly imported rhesus monkey (Macaca mulatta).Case presentation:Moderate to severe attrition was found in the middle labial portion of the left maxillary canine. No tenderness around the jaw was detected in the physical examination. The WBC count, CRP level, rheumatoid factor level, and other parameters were normal. Irregularity in the joint surface was observed in both TMJs in the radiographic and computed tomographic examinations, but the left TMJ presented more severe irregularity. It was determined that the removal of the locked portion of the left canine would alleviate the case of lockjaw and allow intubation with an endotracheal tube. Canine tooth crown reduction was performed for both canine teeth. The mouth opening distance slightly (approximately 5 mm) increased up to 20 mm. We concluded that the attrition of canine teeth was not the reason for lockjaw and ankyloses originating from TMJ disease. Fibrotic synovial tissue and joint surface irregularity were observed by necropsy. The presence of fibrocartilage in most areas of the TMJ was confirmed by histology. The diagnosis was fibrous ankylosis of the TMJ associated with DJD. @*Conclusions@#To the best of our knowledge, this is the first report of degenerative joint disease of the TMJ in a rhesus monkey with fibrous ankylosis of the TMJ.

Evaluation of canine teeth crown reduction technique in macaques / 한국실험동물학회지

Background@#The reduction of canine teeth in adult males in whom permanent canine teeth eruption occurs should be considered due to the safety of humans or other monkeys. The objective of this study was to evaluate the complications of canine teeth reduction in macaques. Case presentation: Canine teeth reductions were performed in 8 rhesus and 2 cynomolgus macaques. Complications related to canine teeth reduction were evaluated at one to three week intervals during the experimental period by gross examination, CBC, and monitoring of appetite. One monkey showed a fistula due to periapical abscess and neutrophilia more than 2 years after canine teeth reduction, and extraction of the diseased canine tooth was performed; the other 9 monkeys showed no complications during the observation period. This report shows the effectiveness of canine teeth reduction with few complications. @*Conclusion@#Canine teeth reduction in male macaques is an acceptable procedure for reducing the severity of injury to humans or other monkeys.

Gold Thread Implantation for Female Sexual Dysfunction and Vaginal Laxity: A Preliminary Investigation

Objectives@#We evaluated the efficacy of gold thread implantation (GTI) in the vulva and vagina to improve female sexual dysfunction (FSD) and vaginal laxity. @*Methods@#A retrospective chart review was conducted on 46 women who underwent GTI between 2017 and 2018 at our institution.Physicians interviewed patients using questionnaires at baseline and 1–3 months post-treatment. The questionnaires consisted of eight questions: vaginal laxity, vaginal dryness, pain during intercourse, sexual satisfaction during intercourse, sexual arousal confidence, sexual satisfaction of partner, frequency, and maintaining lubrication. @*Results@#Overall, participants experienced significant improvement after GTI treatment (P < 0.0001). The median score of vaginal laxity was 3 (slightly loose) at baseline and 5 (slightly tight) at post-treatment. Vaginal dryness also improved from 4 (moderate) at baseline to 2 (little) at post-treatment. The degree of pain during intercourse decreased from 3 to 1. The sexual satisfaction score was 3 (moderately dissatisfied) at baseline and 4 (about equally satisfied and dissatisfied) at post-treatment. Sexual confidence of arousal increased from a score of 3 (low confidence) at baseline to 4 (moderate confidence) at post-treatment. They perceived greater partner sexual satisfaction, moving from a score of 2 to 4. Participants reported lubrication was more frequent during sexual activity, which was maintained until completion of sexual activity. Both scores regarding lubrication increased from 3.5 at baseline to 5 at post-treatment. @*Conclusions@#GTI may be an option for FSD and vaginal laxity.

Improved immune responses and safety of foot-and-mouth disease vaccine containing immunostimulating components in pigs

Background@#The quality of a vaccine depends strongly on the effects of the adjuvants applied simultaneously with the antigen in the vaccine. The adjuvants enhance the protective effect of the vaccine against a viral challenge. Conversely, oil-type adjuvants leave oil residue inside the bodies of the injected animals that can produce a local reaction in the muscle. The longterm immunogenicity of mice after vaccination was examined. ISA206 or ISA15 oil adjuvants maintained the best immunity, protective capability, and safety among the oil adjuvants in the experimental group. @*Objectives@#This study screened the adjuvant composites aimed at enhancing foot-andmouth disease (FMD) immunity. The C-type lectin or toll-like receptor (TLR) agonist showed the most improved protection rate. @*Methods@#Experimental vaccines were fabricated by mixing various known oil adjuvants and composites that can act as immunogenic adjuvants (gel, saponin, and other components) and examined the enhancement effect on the vaccine. @*Results@#The water in oil (W/O) and water in oil in water (W/O/W) adjuvants showed better immune effects than the oil in water (O/W) adjuvants, which have a small volume of oil component. The W/O type left the largest amount of oil residue, followed by W/O/W and O/W types. In the mouse model, intramuscular inoculation showed a better protection rate than subcutaneous inoculation. Moreover, the protective effect was particularly weak in the case of inoculation in fatty tissue. The initial immune reaction and persistence of long-term immunity were also confirmed in an immune reaction on pigs. @*Conclusions@#The new experimental vaccine with immunostimulants produces improved immune responses and safety in pigs than general oil-adjuvanted vaccines.

Stable Expression of Bovine Integrin Beta-6 Increases Susceptibility of Goat Kidney Cell Line to Foot-and-mouth Disease Virus

The integrins αvβ1, αvβ3, αvβ6, and αvβ8 are known to be the natural receptors of foot-and-mouth disease virus (FMDV). Among them, integrin αvβ6 is considered a major receptor for FMDV. We performed protein expression of full-length bovine integrins αv, β3, and β6 and confirmed the high efficiency of bovine αvβ6 as the FMDV receptor in FMDV non-permissive SW 480 cells. Next, we established the black goat kidney (BGK) cell line, stably expressing bovine integrin β6 (BGK-β6-4). We observed that BGK-β6-4 cells had significantly enhanced sensitivity to FMDV compared with that of BGK cells (P<0.05). In addition, BGK-β6-4 cells had equal or higher sensitivity to several serotypes of FMDV compared with that of other FMDV permissive cell lines, such as BHK-21 and IBRS-2. In conclusion, we established a promising novel goat cell line, BGK-β6-4, which can be used to isolate or culture FMDV. Furthermore, the BGK-β6-4 cell line may serve as a promising tool for studying integrin αvβ6 receptor functions.

New foot-and-mouth disease vaccine, O JC-R, induce complete protection to pigs against SEA topotype viruses occurred in South Korea, 2014–2015

Foot-and-mouth disease (FMD) is an acute epidemic that spreads rapidly among cattle and pigs. In 2014, in Korea, despite enforced vaccination, the type O Southeast Asia (SEA) topotype viruses (Mya-98 lineage) infected mainly cattle and pigs simultaneously, thereby causing enormous damage. If a vaccine that is completely protective against this FMD virus is developed and used, it can become a very important preventive measure in Asia, which is where this type of virus mainly circulates. The SEA topotype has been steadily evolving and transforming into new variations since it became epidemic in Asia. Therefore, it became necessary to develop a new vaccine that could provide protection against the FMD virus strain that was responsible for the 2014–2015 outbreak in Korea. This study aimed to develop a vaccine that would provide complete protection against the SEA topotype FMD virus to control sporadic FMD outbreaks, which occur despite the enforcement of vaccination, and to completely prevent virus shedding, thereby preventing the virus from spreading. The vaccine candidate virus developed in this study showed low pathogenicity and can be distinguished from the wild-type FMD virus strain. The developed vaccine was able to protect mice from SEA and Middle East–South Asia topotype virus strains and induced high titers of antibodies against both virus strains in pigs, thereby confirming the sufficiency of its protective function. In particular, the results of the SEA topotype virus challenge test in pigs revealed that perfect immunity was created in the vaccinated pigs, without virus shedding and viremia.

Needleless intradermal vaccination for foot-and-mouth disease induced granuloma-free effective protection in pigs

Vaccination is one of the most effective ways of controlling and preventing foot-and-mouth disease (FMD) outbreaks. The effective prevention of this disease requires the use of high-quality vaccines to meet the criteria that enable customers to use them simply. The administration of FMD vaccines containing oil-based adjuvants in pigs can induce the formation of granuloma in the muscle of the vaccinated, which makes these vaccines a less preferable option. Therefore, it is important to establish an FMD vaccine and vaccine delivery tool that offers better immunity and safer application. This study compared the immune responses of intramuscular and needleless intradermal vaccination in pigs. When the same amount of an FMD virus (FMDV) antigen was administered to pigs, both the intradermally and intramuscularly vaccinated groups were protected completely against a challenge of the homologous FMDV, but the intramuscularly vaccinated group showed an overall higher level of neutralizing antibodies. Importantly, the formation of granuloma in muscle could be excluded in the intradermally vaccinated group. Of the oil-based adjuvants selected in this study, ISA 207 was effective in eliciting immunogenicity in intradermal vaccination. In conclusion, a new vaccine formula can be chosen for the delivery of intradermal route to exclude the possibility of local reactions in the muscle and generate protective immunity against an FMDV challenge.

Effect of Sperm DNA Fragmentation on Embryo Quality in Normal Responder Women in In Vitro Fertilization and Intracytoplasmic Sperm Injection

PURPOSE: To investigate the associations between sperm DNA fragmentation (SDF) and embryo formation rate in normal responder women to in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). MATERIALS AND METHODS: Fifty-three consecutive, fresh IVF/ICSI cycles performed from 2014 to 2017 were selected. All women were normal responders (4 to 14 mature oocytes were retrieved) and at least one normally fertilized oocyte with two pronuclei was obtained in all cycles. Semen was collected on the day of oocyte retrieval, and SDF levels were measured by sperm chromatin dispersion test (Halosperm assay). At day 3 after insemination, embryo quality was evaluated by morphologic criteria and categorized as A/B/C/D. Top quality embryo were defined as grade A embryos with seven cells or more. RESULTS: SDF levels showed a positive linear correlation with the male's age (r=0.307, p=0.025) and a negative linear correlation with sperm motility (r=−0.491, p70%, the cut-off value SDF was <30.7% for each. Among individuals with SDF <30.7%, the median top-quality or grade A embryo formation rate was significantly higher than that among individuals with SDF ≥30.7% (38.1% vs. 20.0%, p=0.038; 50% vs. 25.0%, p=0.017). CONCLUSION: In normal responder women, high SDF level resulted in low day 3 embryo formation rates. Our results suggest a paternal effect on embryo quality in IVF/ICSI cycles.

Vaginal sling implant misdiagnosed as rectal subepithelial tumor

As cosmetic procedures receive increasing attention from the media, female genital cosmetic surgery (FGCS) has become quite popular in Korea. The safety and efficacy of these surgeries and procedures have yet to be thoroughly documented. We report a case of a 47-year-old woman who underwent a vaginal sling implantation, which resulted in the misdiagnosis of a rectal subepithelial tumor during endoscopic mucosal resection (EMR). This patient suffered an iatrogenic rectal perforation during the EMR, which necessitated an exploratory operation. The sling implant was removed via the vaginal approach, and a primary repair of the vaginal and rectal walls was performed. The patient subsequently showed no sign of complication at her 6-month follow-up. Patients need to be educated about the importance of reporting a history of FGCS prior to undergoing surgical or endoscopic procedures. Also, physicians have to check the medical history of patient thoroughly to avoid misdiagnoses and unnecessary treatment.

Successful Robotic Gastrectomy Does Not Require Extensive Laparoscopic Experience

PURPOSE: We evaluated the learning curve and short-term surgical outcomes of robot-assisted distal gastrectomy (RADG) performed by a single surgeon experienced in open, but not laparoscopic, gastrectomy. We aimed to verify the feasibility of performing RADG without extensive laparoscopic experience. MATERIALS AND METHODS: Between July 2012 and December 2016, 60 RADG procedures were performed by a single surgeon using the da Vinci® Surgical System (Intuitive Surgical). Patient characteristics, the length of the learning curve, surgical parameters, and short-term postoperative outcomes were analyzed and compared before and after the learning curve had been overcome. RESULTS: The duration of surgery rapidly decreased from the first to the fourth case; after 25 procedures, the duration of surgery was stabilized, suggesting that the learning curve had been overcome. Cases were divided into 2 groups: 25 cases before the learning curve had been overcome (early cases) and 35 later cases. The mean duration of surgery was 420.8 minutes for the initial cases and 281.7 minutes for the later cases (P<0.001). The console time was significantly shorter during the later cases (168.6 minutes) than during the early cases (247.1 minutes) (P<0.001). Although the volume of blood loss during surgery declined over time, there was no significant difference between the early and later cases. No other postoperative outcomes differed between the 2 groups. Pathology reports revealed the presence of mucosal invasion in 58 patients and submucosal invasion in 2 patients. CONCLUSIONS: RADG can be performed safely with acceptable surgical outcomes by experts in open gastrectomy.

Protective Effects of Female Reproductive Factors on Lauren Intestinal-Type Gastric Adenocarcinoma

PURPOSE: Gastric cancer shows a male predominance that might be explained by protective effects from estrogens in females. Two Lauren classification histological subtypes, intestinal and diffuse, have distinct carcinogeneses. The purpose of this study was to estimate the effects of sex hormone on female gastric cancer according to Lauren classification. MATERIALS AND METHODS: We reviewed medical records for and administered questionnaires, surveying reproductive and hormonal factors, to 758 patients who underwent gastrectomy for gastric cancer at Samsung Medical Center from May 2012 to November 2014. Clinicopathological characteristics were compared between females and males. The incidence of intestinal-type gastric cancer was compared between females subgroups, consist of premenopausal women and three groups of postmenopausal women (five-year intervals after menopause), and males. The association between reproductive factors and intestinal-type gastric cancer was analyzed by multivariate models for the female group. RESULTS: In total, 227 females (29.9%) and 531 males (70.9%) were included in the analysis. Undifferentiated adenocarcinoma and diffuse-type histology were more frequent in female patients than male patients. While 221 (41.6%) male patients had intestinal-type gastric cancer, no premenopausal female patient had this type of gastric cancer. The incidence of intestinal-type gastric cancer increased with time after menopause, and was similar to males after 10 years from menopause. Parity was associated with an increased risk of intestinal-type gastric cancer in menopausal women. CONCLUSION: These findings support that female sex hormones might be protective against intestinal-type gastric cancer.

Synergistic effect of ribavirin and vaccine for protection during early infection stage of foot-and-mouth disease

In many countries, vaccines are used for the prevention of foot-and-mouth disease (FMD). However, because there is no protection against FMD immediately after vaccination, research and development on antiviral agents is being conducted to induce protection until immunological competence is produced. This study tested whether well-known chemicals used as RNA virus treatment agents had inhibitory effects on FMD viruses (FMDVs) and demonstrated that ribavirin showed antiviral effects against FMDV in vitro/in vivo. In addition, it was observed that combining the administration of the antiviral agents orally and complementary therapy with vaccines synergistically enhanced antiviral activity and preserved the survival rate and body weight in the experimental animals. Antiviral agents mixed with an adjuvant were inoculated intramuscularly along with the vaccines, thereby inhibiting virus replication after injection and verifying that it was possible to induce early protection against viral infection prior to immunity being achieved through the vaccine. Finally, pigs treated with antiviral agents and vaccines showed no clinical signs and had low virus excretion. Based on these results, it is expected that this combined approach could be a therapeutic and preventive treatment for early protection against FMD.

Multiple Primary Malignancies in Patients with Multiple Early Gastric Cancer

PURPOSE: This study aimed to investigate the correlation between multiple early gastric cancer (MEGC) and multiple primary malignancies during the follow-up of patients with gastrectomy. MATERIALS AND METHODS: The number of primary tumors detected in other organs after gastrectomy for early gastric cancer (EGC) has been increasing because of improved survival and surveillance programs. A total of 3,129 patients underwent radical gastrectomy for treatment of EGC at Samsung Medical Center from January 2000 to December 2005. Of these, 3,057 patients were selected and their medical records were retrospectively analyzed. RESULTS: Among the 3,057 patients, 148 (4.8%) had MEGC, 84.5% were male, 57.4% were over 60 years old, 42.6% had a macroscopic type EGC IIb main lesion, and 68.9% had well-differentiated tumors with a significantly high incidence of MEGC. There were no differences between patients with solitary early gastric cancer (SEGC) and those with MEGC with regard to overall survival or recurrence-free survival, but MEGC was an independent risk factor for metachronous primary malignancies in other organs (P=0.004, hazard ratio [HR]=2.444). CONCLUSIONS: MEGC is not a risk factor for poor prognosis after curative gastrectomy, but it is a risk factor for metachronous primary malignancies in other organs during postoperative follow-up; therefore, careful surveillance is needed.

Plexiform Angiomyxoid Myofibroblastic Tumor of the Stomach: a Rare Case

Plexiform angiomyxoid myofibroblastic tumor (PAMT) of the stomach is a very rare mesenchymal tumor of the gastrointestinal tract. We report a case of asymptomatic gastric PAMT that was pathologically confirmed after surgical resection. The tumor had a multinodular plexiform growth pattern, bland-looking spindle cells, and an Alcian blue-positive myxoid stromal matrix rich in small blood vessels. Immunohistochemistry analysis revealed that the tumor cells of the PAMT were positive for smooth muscle actin (SMA) and negative for c-kit, CD34, S-100 protein, epithelial membrane antigen (EMA), and desmin. PAMT should be differentiated from other submucosal tumors of the stomach by immunohistochemical findings. Considering the benign features of this tumor, observation without resection may be an option for the treatment of PAMT if the tumor is asymptomatic.

Aortic dissection accompanied by preeclampsia in a postpartum young woman

Aortic dissection is very rare in obstetrics, but it is a fatal disease. A 37-weeks primigravida woman with dyspnea and pitting edema presented to our emergency room. The patient was diagnosed with preeclampsia and underwent an emergency cesarean section under spinal anesthesia. The patient complained of severe dyspnea after the cesarean section, and the chest computed tomography scan was done. With the finding of aortic dissection, cardiopulmonary arrest occurred 5 hours after the cesarean section, and the patient died without reaction to cardio-pulmonary resuscitation. If a patient with preeclampsia complains of severe dyspnea or chest pain, aortic dissection needs to be suspected and a diagnosis should not be delayed.

Aortic dissection accompanied by preeclampsia in a postpartum young woman

Aortic dissection is very rare in obstetrics, but it is a fatal disease. A 37-weeks primigravida woman with dyspnea and pitting edema presented to our emergency room. The patient was diagnosed with preeclampsia and underwent an emergency cesarean section under spinal anesthesia. The patient complained of severe dyspnea after the cesarean section, and the chest computed tomography scan was done. With the finding of aortic dissection, cardiopulmonary arrest occurred 5 hours after the cesarean section, and the patient died without reaction to cardio-pulmonary resuscitation. If a patient with preeclampsia complains of severe dyspnea or chest pain, aortic dissection needs to be suspected and a diagnosis should not be delayed.

Novel foot-and-mouth disease virus in Korea, July-August 2014

Despite nation-wide immunization with O, A, and Asia 1 type vaccines in Republic of Korea, foot-and-mouth disease type O occurred again in July 2014 after three years and three months. This virus was a Mya-98 strain of the Southeast Asian topotype and was most similar to the identified type that circulated in East Asia in 2014. This was new virus with the deletion of 23 amino acids in 3A/3B1 region and low pathogenic property.

Risk Factors and Tumor Recurrence in pT1N0M0 Gastric Cancer after Surgical Treatment

PURPOSE: This study aimed to evaluate the rate, patterns, and risk factors associated with tumor recurrence in patients with T1N0 gastric cancer. MATERIALS AND METHODS: The medical records of 8,753 patients with pathological T1N0M0 gastric cancer who underwent gastrectomy between 1994 and 2014 at Sungkyunkwan University School of Medicine were examined. RESULTS: Among the 8,753 patients, 95 patients (1.1%) experienced tumor recurrence; this included 31 remnant, 27 hematogenous, 9 lymph nodal, 5 peritoneal, and 23 multiple-site recurrences. When patients were divided into two groups according to the presence of tumor recurrence, the following characteristics were higher in the recurrence group than in the non-recurrence group: older age (≥65 years), male gender, undifferentiated histology, submucosal invasion, and venous invasion. In multivariate analysis, older age, male gender, tumor depth (sm2 and sm3 invasion), and venous invasion were independent risk factors for tumor recurrence. The recurrence rates were 0.7% in patients with less than two risk factors, 1.7% in those with two risk factors, 3.0% in those with three risk factors, and 6.3% in those with four risk factors (P<0.001). CONCLUSIONS: Although tumor recurrence is rare in pT1N0M0 gastric cancer, some patients with certain risk factors demonstrate an increased rate of tumor recurrence. Careful follow-up is required for patients with three or four risk factors.