ESR1 and ESR2 polymorphisms in the BIG 1-98 trial comparing adjuvant letrozole versus tamoxifen or their sequence for early breast cancer.
Estrogen receptor 1 (ESR1) and ESR2 gene polymorphisms have been associated with endocrine-mediated physiological mechanisms, and inconsistently with breast cancer risk and outcomes, bone mineral density changes, and hot flushes/night sweats. DNA was isolated and genotyped for six ESR1 and two ESR2 single-nucleotide polymorphisms (SNPs) from tumor specimens from 3691 postmenopausal women with hormone receptor-positive breast cancer enrolled in the BIG 1-98 trial to receive tamoxifen and/or letrozole for 5 years. Associations with recurrence and adverse events (AEs) were assessed using Cox proportional hazards models. 3401 samples were successfully genotyped for five SNPs. ESR1 rs9340799(XbaI) (T>C) variants CC or TC were associated with reduced breast cancer risk (HR = 0.82,95% CI = 0.67-1.0), and ESR1 rs2077647 (T>C) variants CC or TC was associated with reduced distant recurrence risk (HR = 0.69, 95% CI = 0.53-0.90), both regardless of the treatments. No differential treatment effects (letrozole vs. tamoxifen) were observed for the association of outcome with any of the SNPs. Letrozole-treated patients with rs2077647 (T>C) variants CC and TC had a reduced risk of bone AE (HR = 0.75, 95% CI = 0.58-0.98, P interaction = 0.08), whereas patients with rs4986938 (G>A) genotype variants AA and AG had an increased risk of bone AE (HR = 1.37, 95% CI = 1.01-1.84, P interaction = 0.07). We observed that (1) rare ESR1 homozygous polymorphisms were associated with lower recurrence, and (2) ESR1 and ESR2 SNPs were associated with bone AEs in letrozole-treated patients. Genes that are involved in estrogen signaling and synthesis have the potential to affect both breast cancer recurrence and side effects, suggesting that individual treatment strategies can incorporate not only oncogenic drivers but also SNPs related to estrogen activity.
Publication Date: 2015-11-23
Journal: Breast cancer research and treatment
Plasma estrogen levels, estrogen receptor gene variation, and ischemic arterial disease in postmenopausal women: the three-city prospective cohort study.
In older postmenopausal women, high levels of endogenous estrogen have been related to adverse health outcomes including ischemic arterial disease (IAD). Whether estrogen receptor-α (ESR1) and -β (ESR2) polymorphisms modulate the effects of estrogens on IAD has not been investigated.
In the Three-City prospective cohort study among subjects older than 65 years, we used a case-cohort design in which plasma levels of total and bioavailable 17β-estradiol were measured. After exclusion of postmenopausal women using hormone therapy, a random subcohort of 533 women and 105 incident cases of first IAD events over 4 years of follow-up were analyzed. Five common polymorphisms of ESR1 and ESR2 were genotyped. Hazard ratios (HRs) of IAD for a 1-SD increase in hormones levels by the genotypes were estimated from Cox models after adjustment for cardiovascular risk factors and a correction for multiple testing. We also investigated the role of hemostasis and inflammation as potential mediators.
Neither estrogens nor IAD risk was significantly associated with estrogen receptor polymorphisms. Overall, IAD risk increased with total estradiol [HR1.40, 95% confidence interval (CI) 1.11-1.77]. Stratified analysis by genotypes showed that total estradiol was positively related to IAD risk in women with ESR1 rs9340799-AA genotype but not in women with the AG/GG genotype (HR 1.62, 95% CI 1.22-2.17 and HR 1.03, 95% CI 0.81-1.30, respectively; P for interaction <.05). An additional adjustment for hemostatic variables reduced the HR by about one third in women carrying the rs9340799-AA genotype (HR 1.41, 95% CI 1.06-1.90).
The ESR1 rs9340799 genotype may modify the IAD risk related to high endogenous estrogens levels in older postmenopausal women. Hypercoagulability may act as a mediator.
Publication Date: 2014-05-16
Journal: The Journal of clinical endocrinology and metabolism
Association of estrogen receptor alpha gene polymorphisms with autonomic modulation of heart rate in users and nonusers of oral contraceptives.
This study examined the association between estrogen receptor α gene (ESR1) polymorphisms and blood pressure (BP), heart rate (HR) and autonomic modulation of HR in a sample population.
Two hundred thirty-two young healthy women were selected, and those using oral contraceptives (OC) were compared with nonusers (control group). Short-term HR variability (HRV) was evaluated in both the supine and sitting positions using temporal indices rMSSD [square root of the mean squared differences of successive R-R intervals (RRi) divided by the number of RRi minus one], SDNN (root mean square of differences from mean RRi, divided by the number of RRi) and frequency domain methods. Power spectral components were reported at low frequency (LF) and high frequency (HF) and as LF/HF ratio. ESR1 c.454-397T>C (rs2234693) and c.454-351A>G (rs9340799) polymorphisms were determined by polymerase chain reaction and fragment restriction analysis.
The ESR1 T>C and A>G polymorphisms had no effect on HR, rMSSD, SDNN, LF, HF or LF/HF ratio (supine or sitting), independently of OC use. The ESR1 T-A, T-G, C-A and C-G haplotypes were not associated with HR, BP or HRV.
ESR1 variants had no effect on the autonomic modulation of HR in young women users and nonusers of OC and may not be implicated in cardiovascular risk in young women.
Publication Date: 2012-12-19
Hormone treatment, estrogen receptor polymorphisms and mortality: a prospective cohort study.
The association between hormone treatment (HT) and mortality remains controversial. This study aimed to determine whether the risk of mortality associated with HT use varies depending on the specific characteristics of treatment and genetic variability in terms of the estrogen receptor.
A prospective, population-based study of 5135 women aged 65 years and older who were recruited from three cities in France and followed over six years. Detailed information related to HT use was obtained and five estrogen receptor polymorphisms were genotyped. The total follow-up was 25,436 person-years and during this time 352 women died. Cancer (36.4%) and cardiovascular disease (19.3%) were the major causes of death. Cox proportional hazards models adjusted for age, education, centre, living situation, comorbidity, depression, physical and mental incapacities, indicated no significant association between HT and mortality, regardless of the type or duration of treatment, or the age at initiation. However, the association between HT and all-cause or cancer-related mortality varied across women, with significant interactions identified with three estrogen receptor polymorphisms (p-values = 0.004 to 0.03) in adjusted analyses. Women carrying the C allele of ESR1 rs2234693 had a decreased risk of all-cause mortality with HT (HR: 0.42, 95% CI: 0.18-0.97), while in stark contrast, those homozygous for the T allele had a significantly increased risk of cancer-related mortality (HR: 3.18, 95% CI: 1.23-8.20). The findings were similar for ESR1 rs9340799 and ESR2 rs1271572.
The risk of mortality was not associated with HT duration, type or age at initiation. It was however not equal across all women, with some women appearing genetically more vulnerable to the effects of HT in terms of their estrogen receptor genotype. These findings, if confirmed in another independent study, may help explain the differential susceptibility of women to the beneficial or adverse effects of HT.
Publication Date: 2012-03-30
Journal: PloS one