These results do not support an impact of ATM rs1801516 on late skin reactions of radiotherapy for breast cancer, nevertheless further large studies are still required for conclusive evidences.
Five variants were previously reported to confer risk of various malignant or benign tumors (rs78378222 in TP53, rs10069690 in TERT, rs1800057 and rs1801516 in ATM, and rs7907606 at OBFC1) and four signals are located at established risk loci for hormone-related traits (endometriosis and breast cancer) at 1q36.12 (CDC42/WNT4), 2p25.1 (GREB1), 20p12.3 (MCM8), and 6q26.2 (SYNE1/ESR1).
After adjustment, rs189037 and rs1801516 were significantly associated with breast cancer under the additive model (OR: 1.37 and 1.52, 95% CI: 1.10-1.71 and 1.14-2.04, P: .005 and .005, respectively).
We observed that the ATM 5557G>A polymorphism was significantly correlated with breast cancer risk when all studies were pooled into the meta-analysis (recessive model: odds ratio, OR = 0.67; 95% confidence interval (CI) 0.51-0.89).
The results of this study suggest an association between the ATM codon 1853 Asn/Asp and Asn/Asn genotypes with the development of Grade 3 fibrosis in breast cancer patients treated with radiotherapy.
For European women, strong evidence of association with breast cancer risk was observed for PALB2 c.1592delT OR 3.44 (95% CI 1.39 to 8.52, p=7.1×10<sup>-5</sup>), PALB2 c.3113G>A OR 4.21 (95% CI 1.84 to 9.60, p=6.9×10<sup>-8</sup>) and ATM c.7271T>G OR 11.0 (95% CI 1.42 to 85.7, p=0.0012).
Based on these results, we propose that all female carriers of 40-50 years of age and female ATM c.7271T>G mutation carriers from 25 years of age onwards be offered intensified surveillance programs for breast cancer.
These findings suggest that although the more common c.1066-6T>G variant is not associated with breast cancer, the rare ATM c.7271T>G variant is associated with a substantially elevated risk.
We conclude that the ATM IVS10-6T-->G mutation does not confer a significantly elevated breast cancer risk and that ATM 7271T-->G is a rare event in familial breast cancer.