Doo Hyun Yang

Comparison of Learning Curves and Clinical Outcomes between Laparoscopy-assisted Distal Gastrectomy and Open Distal Gastrectomy

Purpose Most stomach surgeons have been educated sufficiently in conventional open distal gastrectomy (ODG) but insufficiently in laparoscopy-assisted distal gastrectomy (LADG). We compared learning curves and clinical outcomes between ODG and LADG by a single surgeon who had sufficient education of ODG and insufficient education of LADG. Materials and Methods ODG (90 patients, January through September, 2004) and LADG groups (90 patients, June 2006 to June 2007) were compared. The learning curve was assessed with the mean number of retrieved lymph nodes, operation time, and postoperative morbidity/mortality. Results Mean operation time was 168.3 minutes for ODG and 183.6 minutes for LADG. The mean number of retrieved lymph nodes was 37.9. Up to about the 20th to 25th cases, the slope decrease in the learning curve for LADG was more apparent than for ODG, although they both reached plateaus after the 50th cases. The mean number of retrieved lymph nodes reached the overall mean after the 30th and 40th cases for ODG and LADG, respectively. For ODG, complications were evenly distributed throughout the subgroups, whereas for LADG, complications occurred in 10 (33.3%) of the first 30 cases. Conclusions Compared with conventional ODG, LADG is feasible, in particular for a surgeon who has had much experience with conventional ODG, although LADG required more operative time, slightly more time to get adequately retrieved lymph nodes and more complications. However, there were more minor problems in the first 30 LADG than ODG cases. The unfavorable results for LADG can be overcome easily through an adequate training program for LADG.

Palliation of postoperative gastrointestinal anastomotic malignant strictures with flexible covered metallic stents: Preliminary results

AbstractPurpose: To evaluate the efficacy of the placement of covered metallic stents for palliation of gastrointestinal anastomotic strictures secondary to recurrent gastric cancer. Methods: Under fluoroscopic guidance, placement of one or two self-expandable covered metallic stents was attempted perorally in 11 patents (aged 48-76 years) with anastomotic stenoses due to recurrent gastric malignancies. The strictures involved both the afferent and efferent loops in three patients. All patients had poor peroral food intake with severe nausea and vomiting after ingestion. The technical and clinical success was evaluated. Results: Placement of the covered stent was technically successful in 13 of 15 (87%) attempts in ten patients. After the procedure, 9 of 11 (82%) patients overall were able to ingest at least a liquid diet and had markedly decreased incidence of vomiting. During the follow-up of 2–31 weeks (mean 8.5 weeks) there were no major complications. Conclusion: These preliminary results suggest that flexible, covered stents may provide effective palliation of malignant anastomotic stricture secondary to recurrent gastric cancer.

Clinical utility of tumor marker cutoff ratio and a combination scoring system of preoperative carcinoembryonic antigen, carbohydrate antigen 19-9, carbohydrate antigen 72-4 levels in gastric cancer

Purpose The present study is to investigate the clinical utility of tumor marker cutoff ratio (TMR) and develop a TMR combination scoring system based on preoperative tumor marker (TM) levels to prognosis prediction in gastric cancer. Methods We include 1,142 patients for whom two or more TMs were measured and who underwent radical gastrectomy between 1990 and 2003. Results Five-year risk of recurrence (5 YRR) for carcinoembryonic antigen (CEA) TMRs were 18.3%, 29.8%, 61.4% for TMR < 1.0, 1.0 ≤ TMR < 2.0, TMR ≥ 2.0 respectively. 5 YRR for carbohydrate antigen 19-9 (CA 19-9) TMR were 19.7%, 35.6%, 58.4% for TMR < 1.0, 1.0 ≤ TMR < 3.0, TMR ≥ 3.0, respectively. 5 YRR for carbohydrate antigen 72-4 (CA 72-4) TMR were 15.2% and 33.6% for TMR < 1.0 and TMR ≥ 1.0, respectively. We defined high TMR (TMR ≥ 2.0 for CEA, TMR ≥ 3.0 for CA19-9), low TMR (1.0 ≤ TMR < 2 for CEA, 1.0 ≤ TMR < 3.0 for CA 19-9 and 1.0 ≤ TMR for CA72-4) and negative TMR (TMR < 1.0 for all TMs). A TMR combination scoring system was devised with negative scored as zero points, low as 1 and high as 2 for each TMR. TMR scores were divided into four categories (score 0, 1, 2, 3 and above) based on the calculated TMR score and 5 YRR were found to be 12.8%, 23.9%, 45.5%, and 68.3%, respectively (P < 0.05). Multivariate analysis showed that our scoring system was a significant independent prognostic factor. Conclusion Preoperative TMRs such as CEA, CA 19-9, and CA 72-4 show a correlation with prognosis and the TMR combination scoring system could be a useful tool for the prediction of prognosis in gastric cancer.

Epidemiologic Study of Human Epidermal Growth Factor Receptor 2 Expression in Advanced/Metastatic Gastric Cancer: an Assessment of Human Epidermal Growth Factor Receptor 2 Status in Tumor Tissue Samples of Gastric and Gastro-Esophageal Junction Cancer

Purpose The Trastuzumab for gastric cancer (GC) trial identified human epidermal growth factor receptor 2 (HER2) as a predictor of successful treatment with trastuzumab (HER2 receptor targeting agent) among patients with advanced/metastatic GC. To date, the prevalence of HER2 overexpression in the Korean population is unknown. The present study aimed to assess the incidence of HER2 positivity among GC and gastroesophageal (GE) junction cancer samples and the relationship between HER2 overexpression and clinicopathological characteristics in Korean patients. Materials and Methods Tumor samples collected from 1,695 patients with histologically proven GC or GE junction enrolled at 14 different hospitals in Korea were examined. After gathering clinicopathological data of all patients, HER2 status was assessed by immunohistochemistry (IHC) at each hospital, and IHC 2+ cases were subjected to silver-enhanced in situ hybridization at 3 central laboratories. Results A total of 182 specimens tested positive for HER2, whereas 1,505 tested negative. Therefore, the overall HER2-positive rate in this study was 10.8% (95% confidence interval=9.3%–12.3%). The HER2-positive rate was higher among intestinal-type cases (17.6%) than among other types, and was higher among patients older than 70 years and 50 years of age, compared to other age groups. Conclusions Our evaluation of the HER2 positivity rate (10.8%) among Korean patients with GC and GE junction indicated the necessity of epidemiological data when conducting studies related to HER2 expression in GC and GE junction.

The Korean Gastric Cancer Cohort Study: Study Protocol and Brief Results of a Large-Scale Prospective Cohort Study

Purpose This study aimed to establish a large-scale database of patients with gastric cancer to facilitate the development of a national-cancer management system and a comprehensive cancer control policy. Materials and Methods An observational prospective cohort study on gastric cancer was initiated in 2010. A total of 14 cancer centers throughout the country and 152 researchers were involved in this study. Patient enrollment began in January 2011, and data regarding clinicopathological characteristics, life style-related factors, quality of life, as well as diet diaries were collected. Results In total, 4,963 patients were enrolled until December 2014, and approximately 5% of all Korean patients with gastric cancer annually were included. The mean age was 58.2±11.5 years, and 68.2% were men. The number of patients in each stage was as follows: 3,394 patients (68.4%) were in stage IA/B; 514 patients (10.4%), in stage IIA/B; 469 patients (9.5%), in stage IIIA/B/C; and 127 patients (2.6%), in stage IV. Surgical treatment was performed in 3,958 patients (79.8%), endoscopic resection was performed in 700 patients (14.1%), and 167 patients (3.4%) received palliative chemotherapy. The response rate for the questionnaire on the quality of life was 95%; however, diet diaries were only collected for 27% of patients. Conclusions To provide comprehensive information on gastric cancer for patients, physicians, and government officials, a large-scale database of Korean patients with gastric cancer was established. Based on the findings of this cohort study, an effective cancer management system and national cancer control policy could be developed.

The Result of Treatment of Anastomotic Leakage after an Elective Gastrectomy for an Adenocarcinoma

Purpose: The most feared complication of gastrointestinal tract operations is anastomotic leakage, not only because of the presumed individual surgeons culpability but also because of the assumption that this event is often fatal. We have experienced 32 cases of anastomotic leakage after elective gastric resection during 8 years. The purpose of this study was to evaluate the result of their treatment. Materials and Methods: We evaluated the records of 1335 patients who had undergone elective gastric resection for an adenocarcinoma of stomach from January 1995 to October 2003 and conducted a retrospective, multivariate analysis. Results: Of the 1335 patients, 32 () sustained an anastomotic leakage. Anastomotic leakages usually developed on mean postoperative day (range: days).Overall, (10/32) of patients who sustained an anastomotic leakage died. The anastomotic leakages were identifed by radiological study or by operative finding at the site of the duodenal stump (20 patients), the esophagojejunostomy (7), the gastroduodenostomy (4), and the gastrojejunostomy (1). Fourteen patients () underwent a relaparotomy, a drainage procedure in the main, and 18 patients () were treated conservatively. The mortality rates were (6/14) and (4/18), respectively, but this difference was not statistically significant. A coxs proportional hazard analysis showed that a body-mass Index CI: ) and non-enteral feeding (odds ratio 18.27, CI 2.22.150.69) were independent factors of mortality due to anastomotic leakage. Conclusion: Our observations show that anastomotic leakage after an elective gastric resection has a high risk of being fatal. Moreover, for a patient with a body-mass index lower than and/or non-enteral feeding, an anastomotic leakage after an elective gastric resection has a higher risk of being fatal.