title: Does tumor size improve the accuracy of prognostic predictions in node-negative gastric cancer (pT1-4aN0M0 stage)?
abstract: BACKGROUND
  The prognostic importance of tumor size in gastric cancer is unclear. This study investigated whether the inclusion of tumor size could improve prognostic accuracy in node-negative gastric cancer.
  
  
  METHODS
  Clinical and pathological data of 492 patients with node-negative gastric cancer who underwent radical surgery in our department from January 1995 to December 2008 were analyzed. The prognostic accuracy of T stage was compared with that of T stage plus tumor size. The ability of tumor size to improve the 95% confidence interval (CI) of postoperative 5-year survival rate in gastric cancer patients was assessed. Different T stages plus tumor size were further analyzed to assess improvements in prognosis.
  
  
  RESULTS
  Mean tumor size was 3.79±1.98 cm with a normal distribution. Multivariate analysis showed that tumor size and T stage were independent prognostic factors. Postoperative 5-year survival rate tended to decrease as tumor size increased in 1 cm increments. The addition of tumor size to T stage improved accuracy in predicting 5-year survival by 4.2% (P<0.05), as well as improving the 95% CI of postoperative 5-year survival rate by 3.2-5.1%. The addition of tumor size improved the predictive accuracy of postoperative 5-year survival rate by 3.9% (95% CI 70.4%-91.1%, P = 0.033) in patients with stage T3N0M0 tumors and by 6.5% (95% CI 68.7%-88.4%, P = 0.014) in patients with stage T4aN0M0 tumors.
  
  
  CONCLUSIONS
  Tumor size is an independent prognostic factor for survival in patients with node-negative gastric cancer, as well as improving prognostic accuracy in stage T3/4aN0M0 tumors.
authors.affiliation: Department of Gastric Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China.
authors.forename: Mu
authors.initials: M
authors.lastname: Xu
authors.affiliation: Department of Gastric Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China.
authors.forename: Chang-Ming
authors.initials: CM
authors.lastname: Huang
authors.affiliation: Department of Gastric Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China.
authors.forename: Chao-Hui
authors.initials: CH
authors.lastname: Zheng
authors.affiliation: Department of Gastric Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.affiliation: Department of Gastric Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China.
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Xie
authors.affiliation: Department of Gastric Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China.
authors.forename: Jia-Bin
authors.initials: JB
authors.lastname: Wang
authors.affiliation: Department of Gastric Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China.
authors.forename: Jian-Xian
authors.initials: JX
authors.lastname: Lin
authors.affiliation: Department of Gastric Surgery, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Lu
mesh_terms: D005260:Female; D005743:Gastrectomy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000473:pathology* / Q000601:surgery; D016019:Survival Analysis; D047368:Tumor Burden