title: Association between glutathione S-transferases M1 and T1 gene polymorphisms and esophageal cancer prognosi.
abstract: OBJECTIVE
  To investigate the independent factors affecting the prognosis of patients after resection of esophageal cancer, and to inquire into the relationship between GSTM1, GSTT1 gene polymorphisms and esophageal cancer prognosis.
  
  
  METHODS
  The clinical data of 273 patients with esophageal cancer were retrospectively analyzed. The patients were followed-up after their surgery, and the gene polymorphisms of GSTM1 and GSTT1 in each individual were detected by polymerase chain reaction (PCR). The clinical features along with the gene polymorphisms of GSTM1 and GSTT1 associated with the prognosis of patients were analyzed by using the method of univariate analysis and Cox proportional hazard model. The cumulative survival rate was estimated by Kaplan-Meier methods, and the survival curves were compared by using the log-rank test.
  
  
  RESULTS
  The overall cumulative survival rate of first year, third year and fifth year is 94.6%, 58.5% and 17.8%, respectively. The median survival time (MST) is 38.7 months. The results of univariate analysis showed that: infiltration depth, length of tumor, the number of lymph node metastasis, the region of lymph node metastasis and the genetic polymorphism of GSTM1 and GSTT1 gene loci were associated with the survival of postoperative patients. Cox multivariate analysis further indicated that the length of tumor, the number of lymph node metastasis and the combined genotype (1) [GSTM1 (+/+) or (+/-) & GSTT1 (-/-)] were the independent prognostic factors. The length of tumor, the number of lymph node metastasis were the risk factors for the prognosis, and the combined genotype (1) had protective effect on survival when compared with reference [GSTM1 (+/+) or (+/-) & GSTT1 (+/+) or (+/-)].
  
  
  CONCLUSIONS
  The length of tumor, the number of lymph node metastasis were confirmed as the independent prognostic factors of esophageal carcinoma, and the null genotypes for GSTT1 (-/-) might be a protective factor for survival and GSTM1 (-/-) might be a potential negative prognostic factor in patients with esophageal cancer.
authors.affiliation: Department of Epidemiology, School of Public Health, Guangdong Medical University Dongguan 523808, China.
authors.forename: Ge-Nan
authors.initials: GN
authors.lastname: Li
authors.affiliation: People's Hospital of Ci County Ci County 056500, China.
authors.forename: Xue-Min
authors.initials: XM
authors.lastname: Li
authors.affiliation: Department of Epidemiology, School of Public Health, Guangdong Medical University Dongguan 523808, China.
authors.forename: Yang-Qi
authors.initials: YQ
authors.lastname: Liu
authors.affiliation: People's Hospital of Ci County Ci County 056500, China.
authors.forename: Zhi-Qin
authors.initials: ZQ
authors.lastname: Bao
authors.affiliation: People's Hospital of Ci County Ci County 056500, China.
authors.forename: Li-Xia
authors.initials: LX
authors.lastname: Yang
authors.affiliation: People's Hospital of Ci County Ci County 056500, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Wang
authors.affiliation: People's Hospital of Ci County Ci County 056500, China.
authors.forename: Min-Wei
authors.initials: MW
authors.lastname: Li
authors.affiliation: Department of Epidemiology, School of Public Health, Guangdong Medical University Dongguan 523808, China.
authors.forename: Jin-Lin
authors.initials: JL
authors.lastname: Du
authors.affiliation: Department of Epidemiology, School of Public Health, Guangdong Medical University Dongguan 523808, China.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Chen
authors.affiliation: Department of Epidemiology, School of Public Health, Guangdong Medical University Dongguan 523808, China.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Huang
keywords: Esophageal carcinoma; GSTM1; GSTT1; prognostic factors