Polymorphic changes in the GSTM1, CYP2E1 and the CYP2D6 genes have bee
n reported to be individually associated with increased susceptibility
to certain cancers, In the present study, the relationship between ge
netic polymorphism for these genes and development of urinary bladder
cancer among Egyptian patients was investigated, Our results indicate
that the frequency of bladder cancer patients with the GSTM1 null geno
type is significantly higher than that of the normal controls (86.3 an
d 47.6%, respectively) with an odds ratio (OR) of 6.97 (95% CL = 1.59-
30.57, Fisher's exact P = 0.008), In contrast, our investigation faile
d to demonstrate any difference in the distribution of CYP2E1 polymorp
hism between bladder cancer patients and controls as detected by PstI
restriction fragment length polymorphism (RFLP) analysis. RFLP analysi
s of the CYP2D6 gene revealed a non-significant increase in the number
of extensive metabolizers (EM) among the patients compared to the con
trols (68 versus 48%). However, the EM genotypes enhances the risk fur
ther for individuals harboring the GSTM1 null genotype as individuals
harboring both the EM and the GSTM1 null genotypes have an odds ratio
of 14.0 (95% CL = 1.3-151.4, Fisher's exact P = 0.02) compared to indi
viduals harboring the EM and the GSTM1+/+ genotypes. In conclusion, ou
r results indicate that genetic polymorphism, especially in GSTM1 and
CYP2D6 could play an important role as host risk factors for developme
nt of urinary bladder cancer among Egyptians.