title: Outcomes of surgery for gastric cancer with distant metastases: a retrospective study from the SEER database.
abstract: BACKGROUND
  The role of surgical therapy in gastric cancer patients with distant metastases remains controversial. This retrospective analysis was performed to identify whether gastric cancer patients with distant metastases might benefit from surgery.
  
  
  METHODS
  A total of 5185 patients from the SEER database who were initially diagnosed with histologically confirmed gastric cancer with distant metastases from 2004 to 2009 were included. Patients were divided into the following three groups: patients who underwent resection of both the primary tumor and distant metastatic tumors ('PMTR' group), patients who only underwent resection of the primary tumor ('PTR' group) and patients who did not undergo any surgery ('No surgery' group). We employed the Kaplan-Meier analysis, the log-rank test and multivariate Cox proportional hazards regression models to estimate the survival time of the different groups.
  
  
  RESULTS
  A total of 5185 patients had a median survival time (MST) of 9.0 months. The improvement in survival of the 'PMTR' and 'PTR' groups was significantly different compared with that of the 'No surgery' group (MST, 12.0 vs 12.0 vs 9.0 months, respectively, P<0.001; 1-year survival rate, 49.6% vs 49.1% vs 30.1%, respectively, P<0.001; 3-year survival rate, 12.5% vs 15.1% vs 5.8%, respectively, P<0.001), whereas no significant difference was found between the 'PMTR' group and 'PTR' group (P=0.642). Multivariate Cox proportional analysis showed that surgery was an independent prognostic factor ('PMTR', hazard ratio (HR) =0.648, 95% confidence interval (CI) 0.574-0.733, P<0.001; 'PTR', HR=0.631, 95% CI 0.583-0.684, P<0.001).
  
  
  CONCLUSIONS
  This retrospective analysis demonstrated that combined PTR and metastasectomy or PTR alone were independent prognostic factors for survival improvement in gastric cancer patients with distant metastases. Because no statistically significant difference in survival was observed between the 'PMTR' group and 'PTR' group, PTR, which is a more minor surgery, might be more appropriate than PMTR in clinical practice for gastric cancer patients with distant metastases.
authors.affiliation: Department of Medical Oncology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Medical Oncology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.
authors.forename: Yiyao
authors.initials: Y
authors.lastname: Kong
authors.affiliation: Department of Medical Oncology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Weng
authors.affiliation: Department of Medical Oncology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.
authors.forename: Caixia
authors.initials: C
authors.lastname: Dong
authors.affiliation: Department of Medical Oncology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.
authors.forename: Lizhen
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Department of Medical Oncology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.
authors.forename: Ziru
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Gastroenterology, The Second Affiliated Hospital, School of Medicine and Institute of Gastroenterology, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhong
authors.affiliation: Department of Medical Oncology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.|Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, Chinese National Ministry of Education; Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province, China), The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yuan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D013505:Digestive System Surgical Procedures / Q000379:methods*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D059146:Metastasectomy / Q000379:methods*; D008875:Middle Aged; D009362:Neoplasm Metastasis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018426:SEER Program; D013274:Stomach Neoplasms / Q000601:surgery*; D016896:Treatment Outcome
keywords: gastric cancer with distant metastases; outcomes; surgery