Purpose: Currently, trastuzumab plus chemotherapy is the standard first-line therapy for human epidermal growth factor receptor 2 (HER2)-positive advanced or metastatic gastric cancer (mGC) or esophagogastric junction cancer. However, it is not clear whether the prognosis of HER2-positive mGC treated with trastuzumab plus chemotherapy is better than that of HER2-negative mGC treated with chemotherapy as the first-line therapy. Methods: We performed a retrospective study comparing the prognosis of mGC according to first-line treatment with trastuzumab plus chemotherapy or chemotherapy only, at the Korea Cancer Center Hospital from 2011 to 2018. The Kaplan-Meier method and Cox proportional hazards model were used for univariate and multivariate survival analyses. Results: The median overall survival of trastuzumab group was 26.1 months and that of chemotherapy group was 14.8 months (P=0.047). Trastuzumab group had a longer median progression-free survival than chemotherapy group (23.4 vs. 9.2 months, P=0.026). By univariate analysis, sex, age, World Health Organization (WHO) histology, HER2 status, primary tumor site, extent of disease, number of lesions, number of metastatic, measurability of disease, prior gastrectomy, and chemotherapy group are statistically significant. Using multivariate analysis, number of lesions, number of metastatic, prior gastrectomy, and trastuzumab group (hazard ratio, 0.594; 95% confidence interval, 0.384–0.921; P=0.020) were found to be independent prognostic factors of overall survival. Conclusion The result suggests prognosis of HER2-positive mGC treated by trastuzumab plus chemotherapy could be better than that of HER2-negative mGC treated by chemotherapy only. Well-designed prospective cohort studies are needed to confirm the results of this study. HER2 testing should be performed routinely in all patients newly diagnosed with mGC.

Purpose: Currently, trastuzumab plus chemotherapy is the standard first-line therapy for human epidermal growth factor receptor 2 (HER2)-positive advanced or metastatic gastric cancer (mGC) or esophagogastric junction cancer. However, it is not clear whether the prognosis of HER2-positive mGC treated with trastuzumab plus chemotherapy is better than that of HER2-negative mGC treated with chemotherapy as the first-line therapy. Methods: We performed a retrospective study comparing the prognosis of mGC according to first-line treatment with trastuzumab plus chemotherapy or chemotherapy only, at the Korea Cancer Center Hospital from 2011 to 2018. The Kaplan-Meier method and Cox proportional hazards model were used for univariate and multivariate survival analyses. Results: The median overall survival of trastuzumab group was 26.1 months and that of chemotherapy group was 14.8 months (P=0.047). Trastuzumab group had a longer median progression-free survival than chemotherapy group (23.4 vs. 9.2 months, P=0.026). By univariate analysis, sex, age, World Health Organization (WHO) histology, HER2 status, primary tumor site, extent of disease, number of lesions, number of metastatic, measurability of disease, prior gastrectomy, and chemotherapy group are statistically significant. Using multivariate analysis, number of lesions, number of metastatic, prior gastrectomy, and trastuzumab group (hazard ratio, 0.594; 95% confidence interval, 0.384–0.921; P=0.020) were found to be independent prognostic factors of overall survival. Conclusion The result suggests prognosis of HER2-positive mGC treated by trastuzumab plus chemotherapy could be better than that of HER2-negative mGC treated by chemotherapy only. Well-designed prospective cohort studies are needed to confirm the results of this study. HER2 testing should be performed routinely in all patients newly diagnosed with mGC.

BACKGROUND/AIMS: In Korea, the nationwide gastric cancer screening program recommends biennial screening for individuals aged 40 years or older by way of either an upper gastrointestinal series or endoscopy. The national endoscopic quality assessment (QA) program began recommending endoscopy in medical institutions in 2009. We aimed to assess the effect, burden, and cost of the QA program from the viewpoint of medical institutions. METHODS: We surveyed the staff of institutional endoscopic units via e-mail. RESULTS: Staff members from 67 institutions replied. Most doctors were endoscopic specialists. They responded as to whether the QA program raised awareness for endoscopic quality (93%) or improved endoscopic practice (40%). The percentages of responders who reported improvements in the diagnosis of gastric cancer, the qualifications of endoscopists, the quality of facilities and equipment, endoscopic procedure, and endoscopic reprocessing were 69%, 60%, 66%, 82%, and 75%, respectively. Regarding reprocessing, many staff members reported that they had bought new automated endoscopic preprocessors (3%), used more disinfectants (34%), washed endoscopes longer (28%), reduced the number of endoscopies performed to adhere to reprocessing guidelines (9%), and created their own quality education programs (59%). Many responders said they felt that QA was associated with some degree of burden (48%), especially financial burden caused by purchasing new equipment. Reasonable quality standards (45%) and incentives (38%) were considered important to the success of the QA program. CONCLUSIONS: Endoscopic quality has improved after 5 years of the mandatory endoscopic QA program.
Diagnosis ; Disinfectants ; Education ; Electronic Mail ; Endoscopes ; Endoscopy ; Korea* ; Mass Screening ; Motivation ; Specialization ; Stomach Neoplasms

BACKGROUND/AIMS: We evaluated the characteristics of the National Cancer Screening Program (NCSP) and opinions regarding the National Endoscopy Quality Improvement Program (NEQIP). METHODS: We surveyed physicians performing esophagogastroduodenoscopy and/or colonoscopy screenings as part of the NCSP via e-mail between July and August in 2015. The 32-item survey instrument included endoscopic capacity, sedation, and reprocessing of endoscopes as well as opinions regarding the NEQIP. RESULTS: A total of 507 respondents were analyzed after the exclusion of 40 incomplete answers. Under the current capacity of the NCSP, the typical waiting time for screening endoscopy was less than 4 weeks in more than 90% of endoscopy units. Performance of endoscopy reprocessing was suboptimal, with 28% of respondents using unapproved disinfectants or not knowing the main ingredient of their disinfectants and 15% to 17% of respondents not following reprocessing protocols. Agreement with the NEQIP was optimal, because only 5.7% of respondents did not agree with NEQIP; however, familiarity with the NEQIP was suboptimal, because only 37.3% of respondents were familiar with the NEQIP criteria. CONCLUSIONS: The NEQ-IP remains suboptimal in Korea. Given the suboptimal performance of endoscopy reprocessing and low familiarity with the NEQIP, improved quality in endoscopy reprocessing and better understanding of the NEQIP should be emphasized in Korea.
Colonoscopy ; Colorectal Neoplasms ; Disinfectants ; Early Detection of Cancer ; Electronic Mail ; Endoscopes ; Endoscopy* ; Endoscopy, Digestive System ; Korea* ; Mass Screening ; Quality Improvement* ; Recognition (Psychology) ; Stomach Neoplasms ; Surveys and Questionnaires

PURPOSE: This study aimed to identify time-dependent prognostic factors and demonstrate the time-dependent effects of important prognostic factors in patients with advanced gastric cancer (AGC). MATERIALS AND METHODS: We retrospectively evaluated 3,653 patients with AGC who underwent curative standard gastrectomy between 1991 and 2005 at the Korea Cancer Center Hospital. Multivariate survival analysis with Cox proportional hazards regression was used in the analysis. A non-proportionality test based on the Schoenfeld residuals (also known as partial residuals) was performed, and scaled Schoenfeld residuals were plotted over time for each covariate. RESULTS: The multivariate analysis revealed that sex, depth of invasion, metastatic lymph node (LN) ratio, tumor size, and chemotherapy were time-dependent covariates violating the proportional hazards assumption. The prognostic effects (i.e., log of hazard ratio [LHR]) of the time-dependent covariates changed over time during follow-up, and the effects generally diminished with low slope (e.g., depth of invasion and tumor size), with gentle slope (e.g., metastatic LN ratio), or with steep slope (e.g., chemotherapy). Meanwhile, the LHR functions of some covariates (e.g., sex) crossed the zero reference line from positive (i.e., bad prognosis) to negative (i.e., good prognosis). CONCLUSIONS: The time-dependent effects of the prognostic factors of AGC are clearly demonstrated in this study. We can suggest that time-dependent effects are not an uncommon phenomenon among prognostic factors of AGC.
Follow-Up Studies ; Gastrectomy ; Humans ; Korea ; Lymphatic Metastasis ; Lymph Nodes ; Multivariate Analysis ; Prognosis ; Proportional Hazards Models ; Retrospective Studies ; Stomach Neoplasms*

PURPOSE: Peritoneal lavage cytology is part of the routine staging workup for patients with advanced gastric cancer. However, no quality assurance study has been conducted to show variations or biases in peritoneal lavage cytology results. The aim of this study was to demonstrate a test execution variation in peritoneal lavage cytology between investigating surgeons. MATERIALS AND METHODS: A prospective cohort study was designed for determination of the positive rate of peritoneal lavage cytology using a liquid-based preparation method in patients with potentially curable advanced gastric cancer (cT2~4/N0~2/M0). One hundred thirty patients were enrolled and underwent laparotomy, peritoneal lavage cytology, and standard gastrectomy, which were performed by 3 investigating surgeons. Data were analyzed using the chi-square test and a logistic regression model. RESULTS: The overall positive peritoneal cytology rate was 10.0%. Subgroup positive rates were 5.3% in pT1 cancer, 2.0% in pT2/3 cancer, 11.1% in pT4a cancer, and 71.4% in pT4b cancer. In univariate analysis, positive peritoneal cytology showed significant correlation with pT stage, lymphatic invasion, vascular invasion, ascites, and the investigating surgeon. We found the positive rate to be 2.1% for surgeon A, 10.2% for surgeon B, and 20.6% for surgeon C (P=0.024). Multivariate analysis identified pT stage, ascites, and the investigating surgeon to be significant risk factors for positive peritoneal cytology. CONCLUSIONS: The peritoneal lavage cytology results were significantly affected by the investigating surgeon, providing strong evidence of test execution variation that could be related to poor diagnostic accuracy and stage migration in patients with advanced gastric cancer.
Ascites ; Bias (Epidemiology) ; Cohort Studies ; Gastrectomy ; Humans ; Laparotomy ; Logistic Models ; Methods ; Multivariate Analysis ; Peritoneal Lavage* ; Prospective Studies ; Risk Factors ; Stomach Neoplasms*

PURPOSE: The effects of hepatic resection on patients with metastatic tumors from gastric adenocarcinomas are unclear. Therefore, we analyzed early clinical outcomes in patients who underwent surgical resection for hepatic metastases from gastric adenocarcinomas. MATERIALS AND METHODS: From January 2003 to December 2010, 1,508 patients with primary gastric cancers underwent curative gastric resections at the Korea Cancer Center Hospital. Of these patients, 12 with liver-only metastases underwent curative hepatic resection. Their clinical data were analyzed retrospectively. RESULTS: The median follow-up period was 12.5 months (range, 1~85 months); no operative mortalities or major complications were observed. Three patients underwent synchronous resections, and 9 underwent metachronous resections. In the latter group, the median interval between gastrectomy and hepatectomy for hepatic metastasis was 10.5 months (range, 5~47 months). The overall 1- and 5-year survival rates of these 12 patients were 65% and 39%, respectively, with a median overall survival of 31.0 months; 2 patients survived for >5 years. CONCLUSIONS: Hepatic resection can be a feasible procedure for treating hepatic metastases from gastric adenocarcinomas. Although this study was small and involved only selected cases, the outcomes of the hepatic resections were comparable and long-term (>5 years) survivors were identified. Surgical resection of the liver can be considered a feasible option in managing hepatic metastases from gastric adenocarcinomas.
Adenocarcinoma ; Follow-Up Studies ; Gastrectomy ; Hepatectomy ; Humans ; Korea ; Liver ; Neoplasm Metastasis ; Stomach Neoplasms ; Survival Rate ; Survivors

PURPOSE: Infection with Helicobacter pylori is an important risk factor for gastric cancer in humans. We compared the clinicopathologic features of gastric cancer patients based on H. pylori infection. MATERIALS AND METHODS: We prospectively studied 155 patients who had gastric cancer and underwent gastrectomies in 1 hospital in Korea. We examined H. pylori infections using the rapid urease test (RUT) with gastrectomy specimens and collected clinical and pathologic data. RESULTS: The number of H. pylori infections based on the RUT was 137 (88%). The H. pylori-negative group was significantly associated with AGC and tumor histology. H. pylori infection was significantly correlated with type I/IIa in EGC and type III/IV/V in AGC. AGC was significantly correlated with larger tumor size, lymphatic invasion, perineural invasion, and H. pylori infection based on univariate and multivariate analyses. CONCLUSIONS: We report the prevalence of H. pylori based on the RUT in gastric cancer patients. H. pylori infection influences the tumor histology, progression, and growth type of gastric cancer.
Gastrectomy ; Helicobacter ; Helicobacter pylori ; Humans ; Korea ; Phenotype ; Prevalence ; Prospective Studies ; Risk Factors ; Stomach Neoplasms ; Urease

PURPOSE: Infection with Helicobacter pylori is an important risk factor for gastric cancer in humans. We compared the clinicopathologic features of gastric cancer patients based on H. pylori infection. MATERIALS AND METHODS: We prospectively studied 155 patients who had gastric cancer and underwent gastrectomies in 1 hospital in Korea. We examined H. pylori infections using the rapid urease test (RUT) with gastrectomy specimens and collected clinical and pathologic data. RESULTS: The number of H. pylori infections based on the RUT was 137 (88%). The H. pylori-negative group was significantly associated with AGC and tumor histology. H. pylori infection was significantly correlated with type I/IIa in EGC and type III/IV/V in AGC. AGC was significantly correlated with larger tumor size, lymphatic invasion, perineural invasion, and H. pylori infection based on univariate and multivariate analyses. CONCLUSIONS: We report the prevalence of H. pylori based on the RUT in gastric cancer patients. H. pylori infection influences the tumor histology, progression, and growth type of gastric cancer.
Gastrectomy ; Helicobacter ; Helicobacter pylori ; Humans ; Korea ; Phenotype ; Prevalence ; Prospective Studies ; Risk Factors ; Stomach Neoplasms ; Urease

PURPOSE: Gastric cancer is prevalent in Korea, therefore the purpose of this study was to determine the clinicopathologic characteristics, 5-year survival rate, and prognostic factors for gastric patients who underwent gastrectomy by a single surgeon. MATERIALS AND METHODS: A total of 1,435 patients diagnosed with gastric cancer who underwent gastrectomy in the Department of Korean Gastric Cancer Center at Seoul Paik Hospital between September 1998 and August 2003, and the gender, age, location and size of the tumor, visual and histologic analysis, depth of invasion, lymph node metastasis, invasion (perineural, venous, and lymphatic), and surgical method were examined retrospectively. RESULTS: The ratio between males and females was 2.29:1, and the average age was 56.7 years. Based on the UICC TNM classification, the patients were distributed as follows: IA 35.4%, IB 14.1%, II 12.6%, IIIA 12.3%, IIIB 8.3% and IV 17.3%. The 5-year survival rate was 69.6%. The results of univariate analysis showed that there were significant differences in the survival rate by age, location and size of tumor, Borrmann type, level of differentiation, Lauren's classification, depth of invasion, metastasis in lymph nodes, UICC TNM stage, invasion (perineural, venous, and lymphatic), and surgical method. Based on multivariate analysis, only the depth of invasion and lymph node metastasis were independent prognostic factors. CONCLUSION: Although various clinicopathologic characteristics affect the prognostic factors of the patients with gastric cancer, the results of this study showed that the stage of disease, such as depth of invasion and metastasis in lymph nodes, are the most critical factors. There is a need to establish the diagnosis of gastric cancer early and to study and develop various treatment methods based on the diagnostic factors in order to improve the survival of patients with gastric cancer.
Female ; Gastrectomy ; Humans ; Korea ; Lymph Nodes ; Male ; Multivariate Analysis ; Neoplasm Metastasis ; Retrospective Studies ; Stomach Neoplasms ; Survival Rate