title: Geographic difference in safety and efficacy of systemicchemotherapy for advanced gastric or gastroesophagealcarcinoma: a meta-analysis and meta-regression.
abstract: BACKGROUND
  The standard of chemotherapy regimens for advanced or metastatic gastric cancer and the clinical outcome were heterogeneous in Asian versus non-Asian countries. This study aimed to explore predictors of safety and efficacy of chemotherapy for patients with advanced or metastatic gastric cancer.
  
  
  METHODS
  Treatment group-based meta-analysis and met a regression were performed to analyze results of randomized trials published since 2005 for advanced or metastatic gastric cancer patients who received systemic chemotherapy as first-line treatment. Data were extracted and synthesized according to the Cochrane guidelines.
  
  
  RESULTS
  Twenty-five trials (8 Asian, 17 Western or international) with 56 treatment groups were analyzed. Asian trials reported a lower percentage of gastroesophageal junctional carcinoma, higher percentage of diffuse type histology, and more frequent use of second-line chemotherapy. Meta-analysis revealed significant heterogeneity both in treatment safety (grade 3–4 neutropenia and diarrhea) and efficacy [6-month progression-free survival(PFS) and 1-year overall survival (OS)]. Meta-regression analyses indicate that Asian trials are associated with an 8.2% lower incidence of grade 3–4 neutropenia and 2.1%lower incidence of grade 3–4 diarrhea. A lower percentage of patients with gastroesophageal junction carcinoma and the use of combination regimens predicted better PFS. The use of second-line chemotherapy predicts better 1-year OS,which will increase by 10% for every 10% increase inpatients who received second-line chemotherapy.
  
  
  CONCLUSIONS
  Geographic region (Asian vs. non-Asian) is an independent predictor of safety in systemic therapy for gastric cancer.
authors.affiliation: Department of Oncology, National Taiwan University Hospital, 7 Chung-Shan South Road, Zhongzheng District, Taipei 100, Taiwan.
authors.forename: Chiun
authors.initials: C
authors.lastname: Hsu
authors.forename: Ying-Chun
authors.initials: YC
authors.lastname: Shen
authors.forename: Chia-Chi
authors.initials: CC
authors.lastname: Cheng
authors.forename: Ann-Lii
authors.initials: AL
authors.lastname: Cheng
authors.forename: Fu-Chang
authors.initials: FC
authors.lastname: Hu
authors.forename: Kun-Huei
authors.initials: KH
authors.lastname: Yeh
mesh_terms: D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use; D001208:Asia / Q000453:epidemiology; D002277:Carcinoma / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology; D003967:Diarrhea / Q000139:chemically induced; D018572:Disease-Free Survival; D004938:Esophageal Neoplasms / Q000188:drug therapy* / Q000453:epidemiology* / Q000473:pathology; D005060:Europe / Q000453:epidemiology; D006801:Humans; D009503:Neutropenia / Q000139:chemically induced; D016032:Randomized Controlled Trials as Topic; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000453:epidemiology* / Q000473:pathology; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
chemical_list: D000970:Antineoplastic Agents