A population-based case-control study was conducted in 150 newly diagnosed invasive breast cancer and 147 healthy control individuals controls to screen for presence of the ER-α A908G mutation by using single-strand conformation polymorphism (SSCP) analysis and 33Pcycle DNA sequencing.
Collectively, these data demonstrate an important role for the K303R ERalpha mutation in hormonal regulation of tumor growth and estrogen-regulated promoter dynamics in human breast cancer.
Our data suggest that the K303R mutation and the S305 ERalpha residue may be a novel determinant of AI response in breast cancer, and blockade of S305 phosphorylation represents a new therapeutic strategy for treating tumors resistant to hormone therapy.
Expression of the K303R estrogen receptor-alpha breast cancer mutation induces resistance to an aromatase inhibitor via addiction to the PI3K/Akt kinase pathway.
Here, we have optimized the detection of a somatic mutation, an A908G transition of ERalpha, and examined its association with clinical and biological features of invasive breast cancer.
ESR1 A908G mutation-positive breast cancer was significantly associated with a first-degree family history of breast cancer (odds ratio [OR] = 2.69, 95% confidence interval [CI] = 1.15 to 6.28), whereas mutation-negative breast cancer was not.
There was also the suggestion that longer duration of oral contraceptive (OC) use (OR = 3.73, 95% CI = 1.16 to 12.03; Ptrend = 0.02 for use of more than 10 years) and recent use of OCs (OR = 3.63, 95% CI = 0.80 to 16.45; Ptrend = 0.10 for use within 10 years) were associated with ESR1 A908G mutation-positive breast cancer; however, ORs for comparison of the two case subgroups were not statistically significant.