Clinicopathological characteristics of colon cancer diagnosed at primary health care institutions.

BACKGROUND/AIMS: The purpose of this study was to evaluate the clinicopathologic characteristics of colon cancers detected at the SOK Sokpeynhan Internal Medical Network, a nationwide system of primary health care institutions. METHODS: We analyzed 579 colon cancer patients diagnosed using colonoscopy at the SOK network from January 2011 through December 2012. Cancers from the rectum to the splenic flexure were classified as left colon cancer. Patients over 65 were classified as senior. RESULTS: The mean age (±SD) of subjects was 60.9±10.5 years and 61.1% were men. More than one quarter (28.2%) of patients were asymptomatic. The prevalence of left colon cancer was higher (77.9%) than that for right colon cancer. The most frequent macroscopic and histologic types were depressed (58.9%) and moderately differentiated adenocarcinoma (52.2%), respectively. Asymptomatic subjects displayed protruding or well differentiated adenocarcinoma, while symptomatic patients were more likely to display depressed or moderately differentiated adenocarcinoma (P<0.05). The mean age of the right colon cancer group was higher than that for the left colon cancer group (P<0.05). Among symptomatic patients, the most frequent symptoms were bloody stool for patients with left colon cancer and abdominal discomfort for patients with right colon cancer (P<0.05). The prevalence of depressed cancer was higher in older subjects as compared to younger subjects (P<0.05). The prevalence of right colon cancer tended to increase with age, although this difference did not achieve statistical significance (P>0.05). CONCLUSIONS: Study results indicated an increase of colon cancer amongst younger demographics in recent years. The effectiveness of colonoscopy screening was also evident, as asymptomatic patients demonstrated frequent findings of well differentiated adenocarcinomas. Study results also suggested a need for closer examination of older patients, as right colon cancer tended to increase with age.

[Clinicopathologic characteristics of superficial gastric cancer diagnosed at primary health care institutions in 2011].

BACKGROUND/AIMS: Stomach cancer is prevalent in Korea. The purpose of this study was to evaluate the characteristics of superficial gastric cancers detected at SOK Sokpeynhan Internal Medical Network, the nationwide primary health care institutions. METHODS: We prospectively analysed the clinicopathologic and endoscopic characteristics of 218 superficial gastric cancer patients diagnosed using gastric endoscopy at SOK network from January 2011 through December 2011. RESULTS: The mean age was 58.5 years old and male to female ratio was 1.7 : 1. Asymptomatic patients were most common (45.0%). The macroscopic classification revealed that simple types (63.8%) were more common than complex types (36.2%). The most common type was IIc (28.4%) and other types were as follows; IIb (16.1%), IIb+IIc (13.3%), IIa (10.6%), III (9.2%), IIa+IIc (7.3%), IIc+IIa (6.0%), IIc+IIb (5.0%). The most commonly involved sites were the body (53.1%) and greater curvature (32.6%) of the stomach. The size of lesion was less than 1 cm (69.3%) and less than 5 mm (33.5%) in diameter. The most common pathologic type was tubular adenocarcinoma (75.7%). Helicobacter pylori infection rate was 50.2%. Fifty five percent of the cases were diagnosed via endoscopy of National Health Insurance Corporation screenings. CONCLUSIONS: Superficial gastric cancers in 2011 at primary health care SOK network were different from those of previous reports. Type IIc was most common but type IIb was more prevalent and the body and greater curvature of the stomach were the most commonly involved sites. Therefore, careful observation of the proximal gastric mucosa and mucosal color change is needed.

Expression of Cyclooxygenase-2 and Bcl-2 in human gastric adenomas.

BACKGROUND: Cyclooxygenase (COX)-2 is the rate-limiting enzyme in prostaglandin synthesis. An increased expression has been implicated in the development and progression of human gastric cancers and colorectal adenomas and cancers. This study aimed to determine the involvement and association of COX-2 and Bcl-2 in precancerous gastric adenomas. METHODS: Seventy-nine gastric polyps were obtained by endoscopic mucosal resection or polypectomy from January, 2000 to July, 2003. Immunohistochemical expression of COX-2 and Bcl-2 was observed, and their relationships with various clinicopathological factors were analyzed. RESULTS: Histologically, 13 hyperplastic polyps and 66 tubular adenomas, of which 17 showed high-grade dysplasia, were observed. Increased COX-2 expression was observed in low-grade and high-grade tubular adenomas compared to hyperplastic polyps (p=0.004 and p=0.001, respectively). COX-2 expression was significantly higher in larger (>1 cm) compared with smaller (<1 cm) tubular adenomas (o=0.034), but no relation was observed in hyperplastic polyps. While Bcl-2 expression differed significantly according to histology, increased Bcl-2 expression was observed especially in COX-2 positive low-grade tubular adenomas. CONCLUSION: COX-2 expression increased in a size-dependent manner in tubular adenomas, suggesting a role in polyp growth. The increased expression of Bcl-2 in tubular adenomas, especially in COX-2 positive tubular adenomas, suggests that COX-2 action may be related to Bcl-2 expression.

[Cyclooxygenase-2 expression according to size and location of gastric and colorectal tubular adenomas].

BACKGROUND/AIMS: Recent studies have shown that cyclooxygenase-2 (COX-2) may be involved in the process of invasion, growth and apoptosis in colorectal carcinoma and in the growth and tumorigenesis in familial adenomatous polyposis. This study was conducted to determine the significance of the expression of COX-2 in gastric and colorectal adenomas. METHODS: Forty-nine samples of gastric adenoma and fifty-seven samples of colorectal adenoma were obtained by endoscopic mucosal resection or polypectomy from 106 patients from January 2000 to July 2003. COX-2 expression was determined by immunohistochemistry. Correlation between COX-2 expression and several clinical factors were compared in each gastric and colorectal adenomas. RESULTS: The expression of COX-2 in epithelial cells was significantly higher in the group with large adenoma (>1 cm) compared with the group with small adenoma (< or =1 cm) in gastric (76.5% vs. 46.7%, p=0.04) and colorectal adenomas (75% vs. 41.5%, p=0.023). Moreover, increased COX-2 expression was shown in distal compared to proximal colorectal adenoma (64.3% vs. 37.9%, p=0.047). CONCLUSIONS: COX-2 was expressed in a size-dependent manner in gastric and colorectal tubular adenomas. The expression of COX-2 was different according to the location of colorectal adenoma. The association of COX-2 expression with the size of adenoma may suggest that the role of COX-2 is not related to the early development of adenoma, but related to the progression of adenoma.

The bone regenerative effect of chitosan microsphere-encapsulated growth hormone on bony consolidation in mandibular distraction osteogenesis in a dog model.

The purpose of this project was to study the effect of chitosan microsphere-encapsulated human growth hormone, which causes sustained release of chitosan and human growth hormone after implantation on early bony consolidation in distraction osteogenesis of a canine model. Forty-eight dogs were used for this study. An external distraction device was applied to the mandibular body after a vertical osteotomy, and the mandibular distraction was started 5 days after the operation at a rate of 1 mm/d up to a 10-mm distraction. The experimental group was divided into a control group (I), hyaluronic acid group (II), chitosan microsphere group (III), and chitosan microsphere-encapsulated human growth hormone group (IV). Normal saline was injected in group I. In group II, a 1-ml volume of hyaluronic acid solution was injected into the distracted area. In the group III, powder of chitosan microspheres and hGH were mixed with a 1-ml volume of hyaluronic acid to make an injectable form, and it was implanted into the distracted area. In group IV, powder of chitosan microsphere-encapsulated hGH was mixed with a 1-ml volume of hyaluronic acid. A total of 1-ml volume of the solution mix was implanted into the distracted area. Five dogs in each group (total of 20 dogs) were killed 3 weeks after completion of distraction. Twenty-eight dogs were killed at 6 weeks. Bone mineral density was 13.1% of the contralateral normal mandible at 3 weeks and 29.6% at 6 weeks in group I, 16.4% at 3 weeks and 40.4% at 6 weeks in group II, 16.6% at 3 weeks and 45.95% at 6 weeks in group III, and 29.6% at 3 weeks and 66.7% at 6 weeks in group IV. The mean three-point failure load was 16.1% in the control group, 34.7% in group II, 41.5% in group III, and 52.1% in group IV compared with the intact contralateral mandible, with statistical significance. In the histological findings, new bone was generated in all groups. In group IV, the formation of active woven bone was observed throughout the distracted area at 6 weeks. The amount of new bone formation in the distracted zone was in the order of group IV, group III, group II, and the control group. In conclusion, these findings suggest that chitosan microsphere-encapsulated hGH seems to be quite effective in early bone consolidation in distraction osteogenesis.

[Clinical efficacy of AST/ALT ratio and platelet counts as predictors of degree of fibrosis in HBV infected patients without clinically evident liver cirrhosis].

BACKGROUND/AIMS: Hepatic fibrosis is an important prognostic factor in chronic hepatitis B. Liver biopsy is a gold standard diagnostic tool but an invasive procedure, so it cannot be done on all patients. We evaluated the clinical efficacy of AST/ALT ratio and platelet counts as predictors of fibrosis in chronic hepatitis B. METHODS: We reviewed retrospectively clinical records of 323 patients, who visited Kyungpook National University Hospital for chronic hepatitis B and underwent liver biopsy from September 1998 to May 2002. Correlation with laboratory parameters with hepatic fibrosis stage was identified. RESULTS: Of 323 patients, there were 278 male patients with mean age 27 (9~59). Platelet counts showed a significant correlation (r=-0.343, p=0.000), and AST/ALT ratio showed a weak but significant correlation (r=0.137, p=0.013) with fibrosis stage. Patients with severe fibrosis or cirrhosis (stage 3 and 4) can be identified to have AST/ALT ratio > 1 and platelet counts < 150,000/mm3, which showed with positive predictive value of 66.7%. Sensitivity, specificity, and negative predictive value were 14.6%, 97.5%, and 77.0%, respectively. CONCLUSIONS: In chronic hepatitis B patients without clinical evidence of cirrhosis, severe hepatic fibrosis might be predicted using laboratory parameters of AST/ALT > 1 in combination with platelet counts. However, its sensitivity is too low to replace liver biopsy.

[Laparoscopic and percutaneous ultrasound guided radiofrequency ablation for hepatocellular carcinoma: a preliminary study].

BACKGROUND/AIMS: Radiofrequency ablation (RFA) is emerging as a new therapeutic method in the management of hepatocellular carcinoma (HCC). We report the results of 64 patients with a follow-up interval of 3 to 19 months. METHOD: Sixty-four patients with 82 nodules underwent ultrasound guided RFA. The mean tumor diameter was 2.5+/-1.0 cm. Laparoscopic ultrasound guided RFA was performed in 38 cases, and percutaneous ultrasound guided RFA in 26 cases. The therapeutic efficacy was evaluated by means of three-phase dynamic abdominal computed tomography (CT) performed within at least one week after ablating. The recurrence was evaluated after treatment by means of abdominal CT and alpha fetoprotein every 3 months. We calculated cumulative recurrence rates, survival rates of patients, and found out complication of RFA. RESULTS: Cumulative recurrence rates in 3, 6, 12 months after RFA was 8.8%, 15.8%, 25.9%. 12 cases were recurred during follow-up. Among them, intrahepatic recurrences were noted in 11 cases, local recurrences in 3 cases. Cumulative survival curves indicated that survival rate was 95% at the third month, 94% at the sixth month, 81% at the twelfth month. After RFA, the alpha fetoprotein level was decreased significantly after 1 month (p<0.05), and serum transaminase levels were transiently elevated (p<0.01) but returned to normal within one week. Complications of RFA were not serious, and resolved spontaneously. CONCLUSION: RFA can be considered a useful new treatment for HCC. Laparoscopic RFA is a useful procedure for the treatment of HCC regardless of its location.