Risk of differentiated thyroid carcinoma and polymorphisms within the susceptibility cancer region 8q24.
BACKGROUND
Genome-wide association studies have shown that the 8q24 region harbours multiple independent cancer susceptibility loci and it was also defined as the "susceptibility cancer region." Thus, it could be hypothesized that genetic variants within this region could play a role in the risk of differentiated thyroid carcinoma (DTC).


METHODS
Six single-nucleotide polymorphisms within 8q24 were analyzed, previously associated with the risk of cancer (i.e., rs6983267, rs1447295, rs10808556, rs7000448, rs13254738, and rs13281615) in a population of 1,250 patients affected by DTC and 1,250 controls from Central and Southern Italy.


RESULTS
A strong association between smoking habit and risk of DTC was found [OR, 1.63; 95% confidence interval (CI), 1.39-1.91; P < 10(-6)]. The polymorphisms rs10808556 and rs1447295 showed an association with the risk of DTC (the strongest were the heterozygotes with OR, 1.38; 95% CI, 1.13-1.68 and OR, 1.35; 95% CI, 1.02-1.78, respectively), but, overall, they were unable to reach the statistically significant threshold following Bonferroni's correction.


CONCLUSIONS
Present study suggested a limited involvement of polymorphisms within 8q24 region in relation to the risk of DTC in Central and Southern Italians.


IMPACT
The exclusion of a relationship between DTC and 8q24 among Italians further highlights the tissue-specificity of this chromosomal segment in relation to human cancer and stresses the importance of other population-specific cofactors.