[Gene-gene and gene-environment interactions as modifier factors of prostatic cancer risk: "a case-only" design study].
BACKGROUND
The role of susceptibility low penetrance genes and environmental factors in the etiology of prostate cancer (PCa) is unclear, but may involve in some cases multiple alleles at multiple loci.


OBJECTIVE
To evaluate the association of gene-gene and gene-environment interactions with PCa.


METHODS
One hundred three subjects with biopsy proven PCa were studied, using a case-only design. All were interrogated about smoking habits. Polymorphisms for Glutathione-S-transferase (GS7) and Cytochrome P4501A1 (CYP1A1), were measured in DNA extracted from peripheral lymphocytes, using a restriction fragment length polymorphism analysis.


RESULTS
Our findings suggest that gene-gene interactions between GSTT1 and CYP1A1 high risk genotypes were positive modifiers and had a high predictive value for the presence of PCa, compared with non-susceptibility genotypes. The interaction between susceptibility genotypes and smoking did not modify the risk for PCa.


CONCLUSIONS
Gene-gene interactions may play a role modulating the susceptibility to PCa in a proportion of affected individuals.
División de Salud Ambiental y Ocupacional, Escuela de Salud Pública, Facultad de Medicina, Universidad de Chile.
Dante
D
Cáceres
Jeannette
J
Iturrieta
Cristian
C
Acevedo
Christian
C
Huidobro
Nelson
N
Varela
Mario
M
Escala
Luis
L
Quiñones
D000368:Aged; D000369:Aged, 80 and over; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics; D004777:Environment; D020022:Genetic Predisposition to Disease; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics; D006184:Habits; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011471:Prostatic Neoplasms / Q000235:genetics*; D012307:Risk Factors
D019363:Cytochrome P-450 CYP1A1; D005982:Glutathione Transferase