The probability of having CaP was increased in men who had nondeleted (functional) genotypes at GSTT1 (odds ratio, 1.83; 95% confidence interval, 1.19-2.80) but not GSTM1 (odds ratio, 1.07; 95% confidence interval, 0.74-1.55).
Smokers that lack either GSTM1 or GSTT1 activity had a slightly higher risk of prostatic cancer than smokers expressing the genes, OR 1.4 (95% CI 0.6-3.3) and 1.6 (0.6-3.9), respectively.
We observed no main effect of smoking (odds ratio, 0.95; confidence interval, 0.69-1.29) or GSTM1 (odds ratio, 1.00; confidence interval, 0.73-1.36) with CaP, but did observe a statistically significant main effect of GSTT1 with CaP (odds ratio, 1.61; confidence interval, 1.14-2.28) as reported previously.
Specific results anticipated from these molecular studies will provide information on factors hypothesized to contribute to prostate cancer risk and that may modify the efficacy of either trial supplement, including: steroid sex hormones and several polymorphic genes that encode proteins affecting androgenic stimulation of the prostate, including the androgen receptor, steroid 5alpha-reductase type II, CYP17, and beta-hydroxysteroid dehydrogenase; polymorphisms of DNA repair genes and carcinogen metabolism genes, including those involved in the activation of chemical carcinogens to reactive intermediates (e.g., CYP1A1) or the detoxification of reactive intermediates (e.g., glutathione S-transferase M1); DNA and protein adducts; and insulin-like growth factors and leptin.
On the contrary, no significant effect on prostate-cancer risk was detectable for either GSTM1 (OR = 0.86, 95% CI = 0.55-1.36) or GSTT1 (OR = 0.78, 95% CI = 0.43-1.42).
The combination analysis of genotypes of the three genes showed that presence of two high-risk genotypes, i.e., null genotype of the GSTM1 or GSTT1 gene, or any Val genotypes of the GSP1 gene, significantly increased the risk of prostate cancer (OR = 2.67, 95% CI = 1.08-6.59, p = 0.03).
Taken together, these findings suggest that Chilean people carrying single or combined GSTM1 and CYP1A1 polymorphisms are more susceptible to prostate cancer.
The GSTM1 null genotype was found in 13.1% of the control subjects; no statistical differences were noted in the frequency of the null genotype in patients with PCa (OR = 1.558, 95% CI = 0.735-3.305).
No increased PC risk was observed for men carrying any of the GSTM1 or GSTT1 genotypes (OR = 1.20, 95% CI 0.75-1.90; P = 0.420 for GSTM1 null and OR = 0.87, 95% CI 0.50-1.51; P = 0.550 for GSTM1 null).
Our findings provide evidence that two or more servings per month of cruciferous vegetables may reduce risk of prostate cancer, especially among men with GSTM1-present alleles, and are consistent with a role of dietary ITCs as chemopreventive agents against prostate cancer.
To assess whether CYP1A1, GSTM1, GSTT1 susceptibility genotypes, smoking status and alcohol consumption factors contribute to PCa risk, gene-gene and gene-environment interactions were analyzed.
Our aim was to investigate whether polymorphisms of glutathione S-transferase M1 (GST M1), insulin-like growth factor-2 (IGF-2), and epidermal growth factor (EGFR) genes could be used as genetic markers for risk of prostate cancer.
In this study, association of the prostate cancer risk with genotype frequencies of the Phase I (CYP1A1) and Phase II (GSTM1 and GSTT1) biotransformation enzymes was investigated in 321 Turkish individuals (152 prostate cancer patients and 169 age-matched male controls).
Our results suggest that a combination of p53cd72, CYP1A1, GSTM1 alleles and smoking plays a significant role in modified prostate cancer risk on the study population, which means that smokers carrying susceptible genotypes might have a significantly higher risk than those carrying non-susceptible genotypes.
In this report, genetic polymorphism of phase I and II metabolic enzyme (CYP2E1, CYP17, GSTM1 and GSTT1) genes, living habits, and risk of prostate cancer (PCa) was studied in 163 patients with prostate carcinoma of Han nationality in Southern China and 202 age-matched controls.
Among Caucasians, heavy smoking increased prostate cancer risk nearly 2-fold in those with the GSTM1 null genotype (OR, 1.73; 95% CI, 0.99-3.05) but this increased risk was not observed in heavy smokers who carried the GSTM1 nondeleted allele (OR, 0.95; 95% CI, 0.53-1.71).
The association between the GSTM1-null genotype and prostate cancer was not different according to cancer aggressiveness defined by stage at diagnosis and Gleason score.