Lack of influence of glutathione S-transferase genotype profile on cancer susceptibility in smokers and nonsmokers.
BACKGROUND
The glutathione-S-transferase (GST) gene family has an important role in the biotransformation and detoxification of different xenobiotics and endogenous carcinogens. GST profile has been associated to an increased risk for several types of tumors in different populations, but ethnic stratification makes data interpretation difficult. The Brazilian population represents a unique model in which the types and frequencies of GST gene polymorphisms are less influenced by ethnicity.


METHODS
To evaluate the influence of GST profile in different age and gender groups regarding the risk of developing cancer and its relationship to smoking habit, the GSTT1, GSTM1, and GSTP1 genotypes of 785 Brazilian patients with cancer and 873 cancer-free controls paired on the basis of sex, age, ethnicity, diet and exercise routine, lifetime occupational history, smoking history, general health conditions, and previous diseases were compared.


RESULTS
A univariate logistic regression analysis demonstrated that age over 45 years (p=0.0417) and smoking (p=0.0015) were related to cancer. Multivariate analysis confirmed the importance of advanced age in susceptibility to cancer (p=0.0001). It was also observed that smoking significantly increased the risk of cancer among individuals over 45 years old (OR: 1.825, 95%CI: 1.241-2.682). However, no correlation between risk of cancer, smoking habit, age, or gender and any of the studied GST polymorphisms was found.


CONCLUSIONS
It is suggested that GST profile does not exert an important impact on the influence of tobacco smoking on cancer risk.
Sampaio
Aline Castaldi
AC
Laboratory of Cancer Molecular Genetics and Division of Oncology, Faculty of Medical Sciences, State University of Campinas-Unicamp, Sao Paulo, Brazil.
Morari
Elaine Cristina
EC
Bufalo
Natassia Elena
NE
Leite
Janaina Luisa
JL
Lima
Carmen Silvia Passos
CS
Ward
Laura S
LS
D000367:Age Factors; D001938:Brazil; D005260:Female; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D016015:Logistic Models; D008297:Male; D009369:Neoplasms / Q000139:chemically induced / Q000235:genetics*; D011110:Polymorphism, Genetic; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects*
D005982:Glutathione Transferase