A case-control study on the effect of apoliprotein E genotype on head and neck cancer risk.
BACKGROUND
The apolipoprotein E gene (apoE) has three major isoforms encoded by the ε2, ε3, and ε4 alleles, with the ε4 allele associated with hypercholesterolemia and the ε2 allele with the opposite effect. An inverse relationship between cholesterolemia and head and neck cancer (HNC) has been previously reported, although the relationship between apoE genotypes and HNC has not been explored to date.


METHODS
Four hundred and seventeen HNC cases and 436 hospital controls were genotyped for apoE polymorphisms. Adjusted odds ratios (ORs) and 95% confidence intervals (CI) from logistic regression were used to explore the relationship between HNC and putative risk factors. A gene-environment interaction analysis was done.


RESULTS
A borderline significant 40% decreased HNC risk (OR, 0.58; 95% CI, 0.31-1.05) was observed for individuals carrying at least one ε2 allele. Females carrying at least one ε2 allele showed a 60% risk reduction (OR, 0.43; 95% CI, 0.21-0.90) for HNC compared with ε3 homozygotes. A statistically significant interaction was found between alcohol use and the ε4 allele (P for interaction = 0.04), with a 2-fold increased risk (OR, 2.06; 95% CI, 0.95-4.48) among ever drinkers with an ε4 allele, with respect to ε3 homozygote nondrinkers.


CONCLUSIONS
Our study provides novel evidence of a possible protective effect of the ε2 allele against HNC, probably due to its increased antioxidant properties.


CONCLUSIONS
According to our results, apolipoprotein E may play a different role in carcinogenesis other than its well-known role in regulating blood serum cholesterol levels.
De Feo
Emma
E
Institute of Hygiene, Università Cattolica del Sacro Cuore, Rome, Italy.
Rowell
Jessica
J
Cadoni
Gabriella
G
Nicolotti
Nicola
N
Arzani
Dario
D
Giorgio
Arianna
A
Amore
Rosarita
R
Paludetti
Gaetano
G
Ricciardi
Gualtiero
G
Boccia
Stefania
S
D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects; D001057:Apolipoproteins E / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006258:Head and Neck Neoplasms / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D020033:Protein Isoforms / Q000235:genetics; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects
D001057:Apolipoproteins E; D020033:Protein Isoforms