Hyung-Min Chin

The role of small intestinal bacterial overgrowth in postgastrectomy patients.

Background  Small intestinal bacterial overgrowth (SIBO) is expected in postgastrectomy patients; however, its role has not been clarified. This study was to estimate the prevalence of SIBO and investigate the clinical role of SIBO in postgastrectomy patients.

Intravascular Papillary Endothelial Hyperplasia (Masson's Hemangioma) of the Liver: A New Hepatic Lesion

Intravascular papillary endothelial hyperplasia (Massons hemangioma) is a disease characterized by exuberant endothelial proliferation within the lumen of medium-sized veins. In 1923, Masson regarded this disease as a neoplasm inducing endothelial proliferation, however, now it is considered to be a reactive vascular proliferation following traumatic vascular stasis. The lesion has a propensity to occur in the head, neck, fingers, and trunk. Occurrence within the abdominal cavity is known to be very rare, and especially in the liver, there has been no reported case up to date. The authors have experienced intravascular papillary endothelial hyperplasia of the liver in a 69-yr-old woman, and report the case with a review of the literature.

Susceptibility of gastric cancer according to leptin and leptin receptor gene polymorphisms in Korea

Purpose Leptin plays an important role in the control of body weight and also has a growth-factor-like function in epithelial cells. Abnormal expression of leptin and leptin receptor may be associated with cancer development and progression. We evaluated the relationship among leptin and leptin receptors polymorphisms, body mass index (BMI), serum leptin concentrations, and clinicopathologic features with gastric cancer and determined whether they could be the risk factor of gastric cancer. Methods We measured the serum leptin concentrations of 48 Korean patients with gastric cancer and 48 age- and sex-matched controls. By polymerase chain reaction-restriction fragment length polymorphism, we investigated one leptin gene promoter G-2548A genotype and four leptin receptor gene polymorphisms at codons 223, 109, 343, and 656. Results There was no significant difference between the mean leptin concentrations of the patient and control groups, while BMI was significantly lower in gastric cancer cases (22.9 ± 3.6 vs. 24.5 ± 2.8 kg/m2, P = 0.021). There was significant association between the LEPR Lys109Arg genotype and gastric cancer risk, heterozygotes for GA genotype had been proved to increased the risk of gastric cancer, and its corresponding odds ratio was 2.926 (95% confidence interval, 1.248 to 6.861). Conclusion Our results suggested that LEPR gene Lys109Arg polymorphism is associated with gastric cancer in Korean patients.

Clinicopathological features of retrorectal tumors in adults: 9 years of experience in a single institution.

Purpose Primary tumors of the retrorectal space in adults are very rare. Most of them are benign masses, but malignant masses are reported on occasion. This study aimed to investigate the clinicopathological features of retrorectal tumors. Methods The medical records of fifteen patients who underwent surgical resection of a retrorectal tumor from March 2002 to April 2010 in our hospital were reviewed retrospectively. Results Out of 15 patients, thirteen were females and two males. About 1.7 patients were diagnosed with retrorectal tumor annually in our hospital. The incidence is one per 1,500 surgeries performed under general anesthesia. An anterior approach was performed in eight patients and a posterior approach with excision of the coccyx in five patients. Combined approach was performed in two patients. Four patients (three in abdominal approach and one in combined approach) underwent laparoscopic resection. The mean size of tumors was 6.2 ± 2.9 cm. Mature teratoma (four) and neurilemmoma (four) were the most common tumors. Except for one case of chondrosarcoma, fourteen tumors were confirmed to be of benign nature in histologic examination. Patients who underwent a transabdominal approach with laparoscopic surgery had no postoperative complication and had a tendency to experience earlier recovery than those with open surgery. Conclusion Surgical resection of a retrorectal tumor is recommended to relieve pressure symptoms and to confirm the diagnosis. A laparoscopic approach may offer excellent visualization of the deep structures in the retrorectal space, reduce surgical trauma, and be helpful for early postoperative recovery.

Leptomeningeal carcinomatosis from gastric cancer: single institute retrospective analysis of 9 cases

Purpose The aim of this study is to investigate the clinical features and outcomes of 9 consecutive patients who suffered with leptomeningeal carcinomatosis (LMC) originating from gastric cancer. Methods Between January 1995 and December 2010, we retrospectively reviewed the medical records of 9 patients with gastric LMC who had been treated at St. Vincents Hospital, The Catholic University of Korea. Results With the exception of 1 patient, the primary gastric cancer was Borrmann type III or IV, and 5 cases had poorly differentiated or signet ring cell histology. TNM stage of the primary gastric cancer was III in 6 patients. The median interval from diagnosis of the primary malignancy to the diagnosis of LMC was 9 months. Headache (6 cases), altered mental status (4 cases), and dysarthria (3 cases) were presenting symptoms of LMC. Computed tomography findings were abnormal in 4 of 7 cases, while magnetic resonance imaging revealed abnormality in 4 of 5 cases. Radiation therapy was administered to 5 patients and intrathecal chemotherapy was administered to only 1 patient. Median overall survival duration from the diagnosis of LMC was 3 months. Conclusion LMC originating from gastric cancer had a fatal clinical course and treatment strategies remain challenging.

Expression of claudin-7 and loss of claudin-18 correlate with poor prognosis in gastric cancer

BACKGROUND The purpose of this study was to evaluate the expression of claudin-3, claudin-7, and claudin-18 in gastric cancer and to determine the significance of these proteins for patient outcome. MATERIALS AND METHODS A total of 134 samples were obtained from surgically resected specimens from patients who were diagnosed with gastric carcinoma at a single institution. Paraffin tissue sections from tissue microarray blocks were examined with immunohistochemistry for the expression of claudin-3, claudin-7, and claudin-18. RESULTS In normal gastric tissues, positive immunoreactivity was detected for claudin-18 but not for claudin-3 or claudin-7. Claudin-3 and claudin-7 were expressed in 25.4% and 29.9% of the gastric cancer tissues, respectively. However, 51.5% of gastric cancer tissues exhibited reduced expression of claudin-18. Claudin-7 expression was significantly lower in cases with diffuse histologic type and positive lymphatic invasion. There was a significant inverse correlation between claudin-18 expression and perineural invasion. In the survival analysis, the overall survival time was shorter in patients with claudin-7 expression than in those without claudin-7 expression. However, the overall survival was longer in patients with claudin-18 expression than in those without claudin-18 expression. CONCLUSIONS Our data suggest that the up-regulation of claudin-3 and claudin-7 and the down-regulation of claudin-18 may play a role in the carcinogenesis of gastric cancer. Furthermore, the expression of claudin-7 and the loss of claudin-18 may be independent indicators of a poor prognosis in patients with gastric cancer.

HMGA1/HMGA2 protein expression and prognostic implications in gastric cancer

BACKGROUND The high mobility group A1 (HMGA1) and high mobility group A2 (HMGA2) proteins are architectural transcription factors that have been implicated in the pathogenesis and progression of multiple malignant tumors, including gastric cancer. The aim of this study was to explore the roles of HMGA1 and HMGA2 in gastric carcinogenesis. METHODS The expression of HMGA1 and HMGA2 was examined in 110 gastric adenocarcinomas, 29 gastric adenomas, and 30 normal controls. The results were correlated with the clinicopathological parameters of the tumors and patient outcome. RESULTS The levels of HMGA1 and HMGA2 proteins were significantly increased in gastric cancer samples compared with adenoma and normal gastric tissues. High HMGA1 nuclear immunoreactivity was not correlated with clinicopathological features; however, high levels of HMGA2 protein were significantly associated with T stage, N stage, lymphatic invasion, perineural invasion, and TNM stage. Moreover, HMGA2 expression was significantly associated with shorter recurrence free survival. Multivariate analysis showed that HMGA2 expression was an independent prognostic factor for tumor recurrence. CONCLUSIONS Our results suggest that HMGA1 and HMGA2 are implicated in gastric carcinogenesis and may play a role in tumor progression towards a more malignant phenotype. The HMGA2 protein may be a useful prognostic marker for predicting tumor recurrence.

Risk factors associated with conversion of laparoscopic simple closure in perforated duodenal ulcer

BACKGROUND Precise patient selection criteria are necessary to guide the surgeon in selecting laparoscopic repair for patients with perforated peptic ulcers. The aims of this study are to report surgical outcomes after surgery for perforated duodenal ulcers and identify risk factors for predicting failure of laparoscopic simple closure for perforated duodenal ulcer. METHODS In total, 77 patients who underwent laparoscopic simple closure for perforated duodenal ulcers from January 2007 to September 2013 were retrospectively analyzed. Patients were divided into totally laparoscopic and conversion groups. The characteristics of patients, intraoperative findings, postoperative complications, conversion rates and suture leakage rates of each group were investigated. RESULTS Laparoscopic repair was completed in 69 (89.6%) of 77 patients, while 8 (10.4%) underwent conversion to open repair. Patients in the conversion group had longer perforation time, larger perforation size, more suture leakage, longer hospital stay, and higher 30-day mortality rate than those in the totally laparoscopic group. The size of perforation was the only risk factor for conversion in multivariable analysis. Patients with an ulcer perforation size of ≥9 mm or with perforation duration of ≥12.5 h had a significantly increased risk for conversion and suture leakage. CONCLUSIONS Ulcer size of ≥9 mm is a significant risk factor for predicting conversion in laparoscopic simple closure. Suture leakage is associated with ulcer size (9 mm) and duration of perforation (12.5 h).

Clinicopathological significance of N-cadherin and VEGF in advanced gastric cancer brain metastasis and the effects of metformin in preclinical models.

Gastric cancer is the second most common cause of cancer-related death worldwide. Although brain metastasis is a rare complication of gastric cancer, no standard therapy for gastric cancer brain metastasis has been established. We attempted to identify biological markers that predict brain metastasis, and investigated how to modulate such markers. A case-control study of patients newly diagnosed with gastric cancer who had developed brain metastasis during follow-up, was conducted. These patients were compared with patients who had advanced gastric cancer but no evidence of brain metastasis. Immunohistochemistry was used to analyze the expression of E-cadherin, N-cadherin, MSS1, claudin-3, claudin-4, Glut1, clusterin, ITGB4, vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR) and p53. The expression of VEGF tended to be higher in the case group (33.3 vs. 0%, p=0.055). Median survival was significantly correlated with vascular invasion (12 vs. 33 months, p=0.008) and N-cadherin expression (36 vs. 12 months, p=0.027). We also investigated the effects of metformin in tumor-bearing mouse models. VEGF expression was decreased and E-cadherin increased in the metformin‑treated group when compared with the control group. The expression of the mesenchymal marker MMP9 was decreased in the metformin-treated group. Brain metastasis of advanced gastric cancer was associated with the expression of VEGF. Metformin treatment may be useful for modulating the metastatic capacity by reducing VEGF expression and blocking epithelial-to-mesenchymal transition.

The rationality of N3 classification in the 7th edition of the International Union Against Cancer TNM staging system for gastric adenocarcinomas: A case-control study

BACKGROUND The 7th edition of the International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) tumor-node-metastasis (TNM) classification system for gastric cancer is more detailed than the 6th edition with respect to tumor depth and lymph node metastasis. The purpose of this study was to evaluate the rationality of the 7th UICC/AJCC TNM classification system, focusing on N3 gastric cancers. METHODS A total of 338 patients with N3 gastric cancer who underwent curative resection with ≥ 16 retrieved lymph nodes at two institutions between January 1997 and December 2007 were included in this study. Patients were divided into the N3a (n = 210) and N3b (n = 128) groups. Clinicopathologic characteristics and survival rates were compared between groups. RESULTS No difference in clinicopathologic characteristics, including age (p = 0.989), sex (p = 0.382), tumor location (p = 0.124), surgery type (p = 0.909), depth of invasion (p = 0.313), histologic type (p = 0.111), and Lauren classification (p = 0.491), was observed between patients with N3a and N3b gastric cancer. However, overall survival (OS) rates of patients with N3a gastric cancer were greater than that of patients with N3b gastric cancer (5-year OS, 46% vs. 28%; 10-year OS, 33% vs. 19%; both p < 0.001). Five-year survival rates differed significantly between patients with T3N3a and T3N3b (p = 0.006) sub-stages and between those with T4aN3a and T4aN3b (p = 0.004) sub-stages. CONCLUSIONS The results of this study support N3 sub-classification for gastric cancers, which warrant differential consideration according to TNM stage.