Polymorphisms of CYP1A1 and GSTM1 genes and susceptibility to oral cancer.
OBJECTIVE
Oral cancer is the fifth most common form of cancer in the world and comprises 6.5% of all cancer deaths. Since one of the major risk factors for oral cancer is tobacco use, we hypothesized that polymorphic genes coding for tobacco carcinogen-metabolizing enzymes may play a role in oral cancer susceptibility.


METHODS
To investigate the association between polymorphisms of the CYP1A1 and GSTM1 genes and risks for oral squamous cell carcinoma (OSCC) in the Korean population, the prevalence of the CYP1A1 Mspl and GSTM1 null polymorphisms were examined in 72 patients with histologically confirmed primary OSCC, as well as in 221 healthy control subjects.


RESULTS
A significant risk increase for oral cancer was observed among subjects with the homozygous CYP1A1 (m2/m2) genotype (OR=3.8, 95% CI=1.9-7.7), but not the GSTM1 null genotype (OR=0.7, 95% CI=0.4-1.3). Risk for oral cancer was significantly increased in subjects with the homozygous CYP1A1 (m2/m2)genotype, regardless of smoking history (smokers; OR=4.4; 95% CI=1.2-16.3; non- smokers OR=4.9; 95% CI=1.9-12.5). Using the potentially most protective genotype GSTM1 (+)/CYP1A1 [(m1/m1)+ (m1/m2)] as the reference group, an increased risk for oral cancer was observed among subjects with the GSTM1 (+)/ CYP1A1 (m2/m2) (OR= 2.0, 95% CI=0.8-5.2), and GSTM1 (-)/ CYP1A1 (m2/m2) (OR=4.9, 95% CI=1.5-15.5) genotypes (p < 0.009, (chi2 trend test).


CONCLUSIONS
Our results suggest that individuals with a genotype of CYP1A1 (m2/m2) and GSTM1 (-) are highly susceptible for OSCC and that the CYP1A1 (m2/m2) genotype is closely associated with increased risk of OSCC in Koreans.
Cha
In-Ho
IH
Department of Oral Biology, Yonsei University College of Dentistry, 134 Sinchon-Dong, Seodaemoon-Gu, Seoul, Korea,
Park
Jong Yun
JY
Chung
Won-Yoon
WY
Choi
Min-Ah
MA
Kim
Hyung-Jun
HJ
Park
Kwang-Kyun
KK
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics*; D005260:Female; D017353:Gene Deletion; D020022:Genetic Predisposition to Disease; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000453:epidemiology / Q000235:genetics*; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology
D019363:Cytochrome P-450 CYP1A1; D005982:Glutathione Transferase