Functional Variations in the ATM Gene and Susceptibility to Differentiated Thyroid Carcinoma

Context: ATM is critical in response to ionizing radiation-induced DNA damage. Objective: Variations in ATM are hypothesized to affect individual susceptibility to thyroid cancer. Our objective was to evaluate the association between ATM polymorphisms and thyroid cancer risk. Design, Participants, and Methods: Six ATM single nucleotide polymorphisms (SNP) were genotyped in two independent case-control series including 592 patients with differentiated thyroid carcinoma (DTC) and 885 healthy individuals. An unconditional logistic regression model was applied to calculate odds ratios (OR) and 95% confidence intervals (CI) for each SNP with respect to risk of DTC and the combination effect of SNP on cancer risk. Results: The risk-allele frequencies of all the SNP were similar in the two case-control populations. Under a dominant model of inheritance, the G allele of ATM rs189037 exhibited a protective effect against DTC (adjusted OR = 0.8; 95% CI, 0.6 -1.0; P = 0.04), and the G allele of rs1800057 was associated with increased risk of DTC (adjusted OR = 1.9; 95% CI, 1.1-3.1; P = 0.02). A protective haplotype (A-G-C-T-C-A) was associated with decreased risk of DTC in non-Hispanic whites (adjusted OR = 0.2; 95% CI, 0.0-0.8; P = 0.03). A significant dose-response relationship was observed between the total number of risk alleles of ATM and DTC risk (P = 0.01). Carriers of a combination of six to seven and eight to 10 risk alleles were at 30% (adjusted OR = 1.3; 95% CI, 1.0-1.7) and 50% (adjusted OR = 1.5; 95% CI, 1.1-2.1) increased risk of DTC, respectively. Conclusion: Individual susceptibility to DTC may be attributable to polymorphisms of ATM, and the associations warrant confirmation in independent studies. (J Clin Endocrinol Metab 97: 1913-1921, 2012)