title: GSTT1-null genotype is a protective factor against bladder cancer.
abstract: OBJECTIVE
  To investigate the effects of homozygous deletions of GSTM1 and GSTT1 and smoking on bladder cancer, we conducted a case-control and ecological study.
  
  
  METHODS
  The case group consisted of 216 patients with bladder cancer and the control group of 449 healthy Koreans. Every subject was personally interviewed to obtain a detailed smoking history, and a multiplex polymerase chain reaction method was used to detect the presence or absence of the GSTM1 and GSTT1 genes. In the ecological study, age-standardized bladder cancer incidence and frequencies of GSTM1 and GSTT1-null types, estimated prevalence of cigarette smoking, and estimated per capita consumption of cigarettes per adult according to nationality and ethnicity were included.
  
  
  RESULTS
  In the Korean case-control data, smoking history and the GSTT1-null genotype were significantly associated with bladder cancer, and the GSTM1-null genotype was not. In the univariate and multivariate analyses with the ecological data of various countries and ethnic groups, cigarette smoking positively, but the frequency of the GSTT1-null type negatively, correlated with the age-standardized bladder cancer incidence.
  
  
  CONCLUSIONS
  These results suggest that the GSTT1-negative genotype might not be a risk factor but a protective factor of bladder cancer.
authors.affiliation: Department of Urology, Chungbuk National University College of Medicine, Cheongju, South Korea.
authors.forename: Wun-Jae
authors.initials: WJ
authors.lastname: Kim
authors.forename: Heon
authors.initials: H
authors.lastname: Kim
authors.forename: Cheol-Hwan
authors.initials: CH
authors.lastname: Kim
authors.forename: Moo-Song
authors.initials: MS
authors.lastname: Lee
authors.forename: Bong Ryoul
authors.initials: BR
authors.lastname: Oh
authors.forename: Hyun Moo
authors.initials: HM
authors.lastname: Lee
authors.forename: Takahiko
authors.initials: T
authors.lastname: Katoh
mesh_terms: D000704:Analysis of Variance; D002295:Carcinoma, Transitional Cell / Q000208:ethnology / Q000235:genetics*; D016022:Case-Control Studies; D016001:Confidence Intervals; D005260:Female; D017353:Gene Deletion; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D007723:Korea; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012306:Risk; D012907:Smoking / Q000009:adverse effects*; D001749:Urinary Bladder Neoplasms / Q000208:ethnology / Q000235:genetics*
chemical_list: D005982:Glutathione Transferase; C413545:glutathione S-transferase T1