Estrogen Levels In Postmenopausal Women Research Articles

Double-Blind, Randomized Trial of Alternative Letrozole Dosing Regimens in Postmenopausal Women with Increased Breast Cancer Risk.

Aromatase inhibitors (AI) profoundly suppress estrogen levels in postmenopausal women and are effective in breast cancer prevention among high-risk postmenopausal women. Unfortunately, AI treatment is associated with undesirable side effects that limit patient acceptance for primary prevention of breast cancer. A double-blind, randomized trial was conducted to determine whether low and intermittent doses of letrozole can achieve effective estrogen suppression with a more favorable side-effect profile. Overall, 112 postmenopausal women at increased risk for breast cancer were randomized to receive letrozole at 2.5 mg once daily (QD, standard dose arm), 2.5 mg every Monday, Wednesday, and Friday (Q-MWF), 1.0 mg Q-MWF, or 0.25 mg Q-MWF for 24 weeks. Primary endpoint was suppression in serum estradiol levels at the end of letrozole intervention. Secondary endpoints included changes in serum estrone, testosterone, C-telopeptide (marker of bone resorption), lipid profile, and quality-of-life measures (QoL) following treatment. Significant estrogen suppression was observed in all dose arms with an average of 75% to 78% and 86% to 93% reduction in serum estradiol and estrone levels, respectively. There were no differences among dose arms with respect to changes in C-telopeptide levels, lipid profile, adverse events (AE), or QoL measures. We conclude that low and intermittent doses of letrozole are not inferior to standard dose in estrogen suppression and resulted in a similar side-effect profile compared with standard dose. Further studies are needed to determine the feasibility of selecting an effective AI dosing schedule with better tolerability.

Aromatase inhibitor-associated bone fractures: a case-cohort GWAS and functional genomics.

Bone fractures are a major consequence of osteoporosis. There is a direct relationship between serum estrogen concentrations and osteoporosis risk. Aromatase inhibitors (AIs) greatly decrease serum estrogen levels in postmenopausal women, and increased incidence of fractures is a side effect of AI therapy. We performed a discovery case-cohort genome-wide association study (GWAS) using samples from 1071 patients, 231 cases and 840 controls, enrolled in the MA.27 breast cancer AI trial to identify genetic factors involved in AI-related fractures, followed by functional genomic validation. Association analyses identified 20 GWAS single nucleotide polymorphism (SNP) signals with P < 5E-06. After removal of signals in gene deserts and those composed entirely of imputed SNPs, we applied a functional validation "decision cascade" that resulted in validation of the CTSZ-SLMO2-ATP5E, TRAM2-TMEM14A, and MAP4K4 genes. These genes all displayed estradiol (E2)-dependent induction in human fetal osteoblasts transfected with estrogen receptor-α, and their knockdown altered the expression of known osteoporosis-related genes. These same genes also displayed SNP-dependent variation in E2 induction that paralleled the SNP-dependent induction of known osteoporosis genes, such as osteoprotegerin. In summary, our case-cohort GWAS identified SNPs in or near CTSZ-SLMO2-ATP5E, TRAM2-TMEM14A, and MAP4K4 that were associated with risk for bone fracture in estrogen receptor-positive breast cancer patients treated with AIs. These genes displayed E2-dependent induction, their knockdown altered the expression of genes related to osteoporosis, and they displayed SNP genotype-dependent variation in E2 induction. These observations may lead to the identification of novel mechanisms associated with fracture risk in postmenopausal women treated with AIs.

Efficacy of Vaginally Applied Estrogen, Testosterone, or Polyacrylic Acid on Sexual Function in Postmenopausal Women: A Randomized Controlled Trial

Female libido is multifactorial and complex. Declining estrogen levels in postmenopausal women affects vaginal function. The aim of this study was to evaluate female sexual function after using topical estrogen, testosterone, or polyacrylic acid as vaginal lubricants with K-Y jelly as a placebo lubricant. This was a randomized controlled clinical trial on 80 postmenopausal women between 40 and 70 years of age with follow-up at the Menopause Clinic of the CAISM Unicamp. The women were randomized to treatment with topical vaginal estrogen, testosterone, polyacrylic acid, or oil lubricant alone, three times a week for a period of 12 weeks from November 2011 to January 2013. We used the Female Sexual Function Index (FSFI) to assess changes in sexual response at baseline, and after 6 and 12 weeks. After 12 weeks of treatment, polyacrylic acid and topical testosterone produced improvements in the FSFI domains of sexual desire, lubrication, satisfaction, reduced pain during intercourse, and total score compared with lubricant alone. Treatment with topical estrogen in comparison with lubricant alone showed an improvement in the FSFI field of desire. The intragroup analysis over the time of the treatment showed improvements in the fields of desire, lubrication, and reduced pain for polyacrylic acid, testosterone, and estrogen. Furthermore, women who used testosterone showed improvements over time in the fields of arousal, orgasm, and satisfaction. Treatment of postmenopausal women with symptoms of vaginal atrophy with polyacrylic acid, testosterone, and estrogen for 12 weeks produced improvements in self-reported female sexual function when compared with a placebo lubricant.

Abstract P1-13-09: Sensitive liquid chromatography-tandem mass spectrometry method for serum estradiol and estrone assessment without derivatisation, overcoming cross reactivity with exemestane

Abstract Objective Measuring serum estrogen levels in postmenopausal women on oral aromatase inhibitors is important but challenging. Direct immunoassays are the most widely used techniques for measuring serum estradiol (E2) in research and clinical laboratories. Unfortunately, commercially available immunoassays for E2 lack precision and accuracy in the low range (&amp;lt;20 ng/l) and are susceptible to interference. In addition, particularly in exemestane users biochemical monitoring of E2 is problematic because exemestane metabolites cross react in most immunoassays for E2. We developed a sensitive, routinely applicable liquid chromatography-tandem mass spectrometry (LC-MSMS) method for E2 and estrone (E1) quantification in human serum without the need for derivatization or an extended extraction protocol. Materials and methods Serum E2 levels, assessed with LC-MSMS and electrochemiluminescence estradiol assay (ECLIA) on Modular E170 from Roche Diagnostics, of 10 breast cancer patients treated with exemestane were compared. Limit of quantification (LOQ) was 1.3 ng/l for LC-MSMS (coefficient of variation &amp;lt;20% and signal-to-noise ratio &amp;gt; 10, own validation) and 5 pg/ml for ECLIA (Roche, according to manufacturer). Results Patients treated with exemestane showed much higher E2 levels when measured by ECLIA compared to E2 levels determined by LC-MSMS (Table 1). All patients, but one, had E2 values below LOQ when assessed with LC-MSMS whereas ECLIA measurements showed higher levels with a large variety (mean: 16.5 ng/l; range: 7-33 ng/l). Results for E2 via ECLIA and LC-MSMS for patients treated with exemestanePatientE2 LC-MSMS ng/lE2 ECLIA ng/l1&amp;lt;1.3212&amp;lt;1.373&amp;lt;1.3124&amp;lt;1.3335&amp;lt;1.3156&amp;lt;1.3227&amp;lt;1.398&amp;lt;1.32692.51010&amp;lt;1.310 Conclusion E2 levels in exemestane users measured with ECLIA from Roche are overestimated, probably due to cross reactivity of its metabolites. Therefore, this assay can not be used in these patients. Here, we demonstrate that this hurdle can be overcome by assessment of estrogen values with LC-MSMS. Our group was able to develop such a sensitive method, without derivatization. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-13-09.

The Effect of Grapefruit Intake on Endogenous Serum Estrogen Levels in Postmenopausal Women

Although grapefruit intake leads to elevated serum estrogen levels when hormones are taken orally, there are no published data on the effect on endogenous levels. We conducted a pilot dietary intervention study among healthy postmenopausal volunteers to test whole grapefruit, 2 juices, and 1 grapefruit soda. Fifty-nine participants were recruited through the Love/Avon Army of Women. The study consisted of a 3-wk run-in, 2 wk of grapefruit intake, and a 1-wk wash-out. Eight fasting blood samples were collected. An additional 5 samples drawn at 1, 2, 4, 8, and 10 hr after grapefruit intake were collected during an acute-phase study for 10 women. Serum assays for estrone (E1), estradiol (E2), estrone-3-sulfate (E1S), dehydroepiandrosterone sulfate, and sex hormone-binding globulin were conducted. Whole grapefruit intake had significant effects on endogenous E1S. Peak effects were seen at 8 hr, increasing by 26% from baseline. No changes in mean E1 or E2 with whole fruit intake were observed. In contrast, fresh juice, bottled juice, and soda intake all had significant lowering effects on E2. The findings suggest an important interaction between grapefruit intake and endogenous estrogen levels. Because endogenous estrogen levels are associated with breast cancer risk, further research is warranted.

Fibromyalgia and breast cancer

The article entitled ‘‘Frequency of fibromyalgia syndrome in breast cancer patients’’ by Akkaya et al. [1], published online in 2012 in your journal, was quite interesting. We perceived the article as an important topic while screening the literature for our own study in which we are researching the frequency of fibromyalgia (FM) in patients with nonmetastatic colorectal cancer. According to the title, we thought that the article defining the prevalence of FM in breast cancer was considerable. Therefore, we wanted to emphasize some points. In this article by Akkaya et al. [1], we first want to point to the missing ‘‘adjuvant’’ terminology. Tamoxifen and aromatase inhibitors (AIs) are part of adjuvant ‘‘endocrine’’ treatment in patients with early-stage breast cancer (ESBC). We would like to draw your attention to the fact that the adjuvant terms for chemotherapy and radiation treatment given to the patients were not expressed clearly. For this reason when the article was first read, we thought that adjuvant treatment was only given with hormone therapy to the patients included in the study. According to the article we understood that 10 patients out of 101 patients with ESBC were diagnosed with FM syndrome according to the 1990 ACR criteria [2]. After further analysis, we now understand that seven of the 10 patients were followed up with hormonotherapy after adjuvant chemo-radiotherapy. We know that AIs cause musculoskeletal menopausal symptoms by lowering estrogen levels in postmenopausal women. In previous studies, when tamoxifen and placebo were compared with AIs, the women using AIs had more musculoskeletal sideeffects. In these studies, arthralgia and myalgia were reported as the most common musculoskeletal side-effects [3]. Therefore, the design of the study group is statistically poor as the frequency of FM is analyzed and, in fact, this situation removes the study from the topic it describes. Because most of the 10 patients (n = 7) diagnosed with FM were taking hormonotherapy, this significantly limited the study which already only had a few patients. If the study’s title was ‘‘the effect of regional and widespread pain on the quality of life in breast cancer patients’’ then perhaps it would more appropriately reflect the contents of the article. Again, in the patients with FM who have widespread pain, by using the tender points diagnosed according to the 1990 ACR criteria, the tender points indicated the radiation and mastectomy areas in the 10 patients. Therefore, the study could only be meaningful if it was performed in a large series, taking the effects of hormonotherapy into account according to the ACR 2010 criteria [4]. In our project, we will research the frequency of FM according to the 2010 ACR criteria in patients with ESBC which we have divided into two groups—those taking hormonotherapy and those not taking it. This comment refers to the article available at doi:10.1007/s10147-012-0377-9.

Abstract 639: The effect of grapefruit intake on endogenous serum estrogen levels in postmenopausal women

Abstract The inhibitory effect of grapefruit juice on the intestinal cytochrome P450 3A4 system interacts with more than 60% of orally administered drugs leading to elevation of their serum concentrations. While grapefruit has been shown to lead to elevated serum levels of estrogens when hormones are administered orally, there are no published data on the effect of grapefruit intake on endogenous levels. To begin to address that data gap, we conducted a dietary intervention study among healthy postmenopausal volunteers to determine whether endogenous estrogen levels are significantly affected by grapefruit consumption. We tested 4 grapefruit products: whole fresh grapefruit, fresh squeezed juice “not from concentrate,” shelf-stable juice from concentrate, and grapefruit soda. The majority of volunteers were recruited through the Love/Avon Army of Women. The six-week study consisted of a run-in period of three weeks, a two-week period of grapefruit consumption, and a one-week wash-out period. Eight fasting blood samples were collected during the study. An additional 5 samples drawn at 1, 2, 4, 8 and 10 hours after initial grapefruit intake were collected during an acute-phase study. Serum assays for estrone (E1), estradiol (E2), estrone-3- sulfate (E1S), and sex hormone-binding globulin (SHBG) were conducted. Sixty-two women participated in the study, 10 of whom also participated in the acute phase. Only the whole grapefruit had statistically significant effects on endogeneous estrogen levels. The largest increases were seen in the women with the highest BMI. The changes were evident at 24 hours and remained relatively constant over the 2 week period. With whole grapefruit at the average BMI of 26.6 kg/m2, E1S increased overall by 10.6% (p=0.031), and at a BMI of 30 kg/m2 this increased to 16.4% (p=0.003). Approximately double the effects were seen around 10 hours after whole grapefruit consumption. The effects of fresh juice consumption were around 25% of these increases but were not statistically significant. Small increases in E1 were seen with whole grapefruit, but no increase was seen in E2. The findings of the present study suggest an important interaction between grapefruit consumption and serum levels of endogenous E1S. The increase in E1S is difficult to interpret in term of risk of breast cancer as we found only a small increase in E1 and failed to find any increase in E2. More detailed studies are needed to gain an understanding how the increased levels of E1S are not reflected in similar increases in E1 and E2, and whether the increased E1S levels are reflected in an increase in E1 and E2 levels in the breast itself. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 639. doi:1538-7445.AM2012-639

HRT decreases DNA and lipid oxidation in postmenopausal women

ABSTRACTBackground Postmenopausal women have increased oxidative stress and decreased antioxidant status. Estrogen has great antioxidant capacity both in vitro and in vivo. Few authors have studied the effect that hormone replacement therapy (HRT) has on the oxidant and antioxidant status and none have studied the effect on DNA oxidation as a possible explanation for the aging process itself.Aim The aim of this study was to evaluate both oxidation and antioxidation markers in postmenopausal woman and to determine the effects that HRT has on them.Method Sixty-two postmenopausal women with similar biophysical characteristics were divided into three groups: (1) 18 not taking any HRT, (2) 20 receiving estrogen-only replacement therapy (ERT, conjugated equine estrogen), and (3) 22 receiving combined estrogen/progestin HRT (conjugated equine estrogen + medroxyprogesterone acetate). Specific molecular oxidative damage was detected by measuring 8- hydroxy-2-deoxy guanosine (8-OH-2dG) (DNA damage), standardized thiobarbituric acid reactive substances (TBARS) (lipid damage) and protein carbonyl (proteins). Antioxidant enzyme activity was detected by measuring catalase activity, and total antioxidant status was measured using 1,1,difenil-2-picril hydrazil. Both ELISA and photometric methods were used.Results 8-OH-2dG levels were significantly lower in women who received combined HRT compared to women who did not receive HRT (ANOVA, p < 0.05). Lipid oxidation was significantly lower in women on ERT compared to women taking no HRT (ANOVA, p < 0.05). Pearson correlation showed that lipid oxidation decreased as the estradiol concentration increased within the study range (r = −0.362, p < 0.05). No statistical difference was noted for protein oxidation and catalase activity among the groups. No statistical difference was found for total antioxidant status between the groups (ANOVA).Conclusions HRT decreases oxidative damage to both DNA and lipids in postmenopausal women. Lipid oxidation status may be inversely related to estrogen levels in postmenopausal women.

Estrogen and Skin

Aging of the skin is associated with skin thinning, atrophy, dryness, wrinkling, and delayed wound healing. These undesirable aging effects are exacerbated by declining estrogen levels in postmenopausal women. With the rise in interest in long-term postmenopausal skin management, studies on the restorative benefits that estrogen may have on aged skin have expanded. Systemic estrogen replacement therapy (ERT) has been shown to improve some aspects of skin. Estrogen restores skin thickness by increasing collagen synthesis while limiting excessive collagen degradation. Wrinkling is improved following estrogen treatment since estrogen enhances the morphology and synthesis of elastic fibers, collagen type III, and hyaluronic acids. Dryness is also alleviated through increased water-holding capacity, increased sebum production, and improved barrier function of the skin. Furthermore, estrogen modulates local inflammation, granulation, re-epithelialization, and possibly wound contraction, which collectively accelerates wound healing at the expense of forming lower quality scars. Despite its promises, long-term ERT has been associated with harmful systemic effects. In the search for safe and effective alternatives with more focused effects on the skin, topical estrogens, phytoestrogens, and tissue-specific drugs called selective estrogen receptor modulators (SERMs) have been explored. We discuss the promises and challenges of utilizing topical estrogens, SERMs, and phytoestrogens in postmenopausal skin management.

Effect of CYP19 rs6493497 and rs7176005 haplotype status on in vivo aromatase transcription, plasma and tissue estrogen levels in postmenopausal women

High plasma levels of estradiol (E 2) are correlated to increased breast cancer risk in postmenopausal women. Recently, a study reported two single nucleotide polymorphisms (SNPs) (rs6493497; C → T and rs7176005; G → A) in the aromatase ( CYP19) promoter 1.1 to be associated with elevated plasma E 2 levels, most likely due to enhanced transcription. In silico predictions suggested increased transcription factor binding for the rs7176005_A allele. We genotyped 46 breast cancer patients for rs6493497 and rs7176005 status and assessed the potential association between CYP19 SNP status and (i) CYP19 mRNA levels in tumour and normal breast tissue, and (ii) estrogen levels in plasma, tumour and normal breast tissue. In addition, we measured CYP19 SNP status and correlated it to plasma estrogen levels in a confirmatory dataset of 108 healthy postmenopausal women. We found no correlation between either of the two SNPs and CYP19 mRNA level. In the breast cancer patients, the rs6493497_T/rs7176005_A variant haplotype was associated with low plasma estrone (E 1) ( p = 0.038) and low E 2 ( p = 0.050) levels; however, no correlation was recorded between SNP status and plasma estrogen levels in the cohort of 108 healthy postmenopausal women. Our findings indicate rs6493497 and rs7176005 status not to enhance CYP19 transcription or increase estrogen levels in postmenopausal women.

Effect of Letrozole on Plasma Lipids, Triglycerides, and Estradiol in Postmenopausal Women with Metastatic Breast Cancer

The aromatase inhibitor letrozole effectively treats breast cancer by decreasing estrogen levels in postmenopausal women. The aim of this prospective study was to evaluate the effect of letrozole on plasma lipids, triglyceride lipase (TGL), and estradiol levels in women with metastatic breast cancer (MBC). Fifty-two postmenopausal women with MBC received letrozole, 2.5 mg/day. Blood samples for assessment of plasma levels of total cholesterol (TC), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, TGL, and estradiol were taken at baseline and after 3, 6, and 12 months of treatment. A nonsignificant increase was found in TC and HDL cholesterol levels after 3 months, which returned to baseline levels after 6 months (p = .794 and p = .444, respectively). LDL cholesterol increased nonsignificantly after 6 months and returned to baseline thereafter (p = .886). The mean estradiol level was suppressed from 44 pmol/l before treatment to <18 pmol/l after 6 months (p = .014). No difference was found in the estradiol suppression rate whether baseline levels were >40 or <40 pmol/l. Letrozole has a safe effect on the lipid and TGL profiles of postmenopausal women with MBC. Estradiol levels were maximally suppressed within 6 months of treatment. The increased levels of TC during treatment were reversible and returned to normal levels after 3 months.

A randomized, placebo-controlled trial (NCIC CTG MAP1) examining the effects of letrozole on mammographic breast density and other end organs in postmenopausal women

Mammographically detected breast density has been correlated with breast cancer risk. Breast density appears to be influenced by hormonal factors including increasing age, postmenopausal status, number of pregnancies, lower body weight, hormone replacement therapy, and tamoxifen therapy. The aromatase inhibitor letrozole profoundly reduces breast and circulating estrogen levels in postmenopausal women. We hypothesize that letrozole may reduce breast density and report here on its effects on mammographic breast density, bone mineral density (BMD), bone biomarkers, plasma hormone, and serum lipid levels. MAP1 was a multicenter, randomized, double-blind, placebo-controlled, feasibility trial in which postmenopausal women with or without prior invasive breast cancer were randomized in a 2:1 ratio of letrozole (2.5 mg daily) or placebo for 12 months and followed for a total of 24 months. Eligible women had an estimated >25% breast density on baseline mammogram. The primary endpoint was change in percent breast density (PD) between the baseline and 12-month mammograms as estimated by a computer-assisted thresholding program. Baseline and 12-month mammographic density was also assessed in a blinded manner by visual inspection. Secondary endpoints included changes in serum hormones, plasma lipid levels, bone biomarkers, and BMD. Data are available for 67 women (44 on letrozole and 23 on placebo). No significant changes in PD were noted between the treatment arms at either 12 or 24 months. No distinguishable difference in density measurements by visual inspection were noted between baseline and 12-month mammograms. A significant decrease in percentage change in T-score of the femoral neck at 12 months was noted in the letrozole arm without other significant changes in BMD parameters. Lipid values did not differ between treatment groups except for a borderline significant decrease in total cholesterol at 3 months among women treated with letrozole. Letrozole therapy was associated with a significant reduction in mean serum estradiol, estrone, and estrone sulfate levels at 12 months, but not at 24 months. A significant increase in serum IGF-1 levels was also noted in the letrozole group compared to the placebo group at both 12 and 24 months. To conclude, compared with placebo, 12 months of letrozole therapy does not appear to have a significant effect on mammographic PD. Twelve months of letrozole was associated with a decrease of uncertain clinical significance in the T-score of the femoral neck at 12 months which was reversible at 24 months with recovery of estrogen levels. Letrozole therapy was found to increase IGF-1 levels at 12 and 24 months.

Regular consumption of apples may promote cardiovascular health

Decline in estrogen levels in postmenopausal women is associated with unfavorable changes in lipid profiles and markers of inflammation placing them at a higher risk for cardiovascular disease (CVD). The present short‐term study examined the effects of daily consumption of 75 g dried apples on lipid profiles, independent atherogenic risk factors including lipoprotein (a) [Lp(a)] and high‐sensitive C‐reactive protein (hs‐CRP), in postmenopausal women. Fifty‐five postmenopausal women not on hormone replacement therapy consumed 75 g of dried apple daily for three months. Overnight fasting blood was collected at baseline and at the end of three months. The findings suggest that CVD protective effect of apple consumption is beyond improving lipid profiles (TC, LDL‐C, and TG) as evident by significant reductions in serum levels of Lp (a) (21±3.2 vs. 19±3.1 ) and hs‐CRP (1.8±0.16 vs. 1.3±0.17). Future studies are warranted to investigate the long‐term favorable effects of apple or its bioactive components consumption in improving endothelial function which is compromised as a result of aging.Grant Funding SourceAbstract submitted to the competition shall just have a title and the abstract body and nothing else

Effect of one-week treatment with vaginal estrogen preparations on serum estrogen levels in postmenopausal women

Approximately 50% of postmenopausal women suffer from vaginal atrophy, and a large proportion of them choose intravaginal estrogen preparations administered for local action to avoid systemic exposure to estrogens and its associated risk of breast and uterine cancer. The primary objective of this study was the evaluation of the systematic bioavailability of estradiol and estrone and the pharmacokinetics of two of the most frequently used intravaginal estrogen preparations, namely Vagifem and Premarin cream. While immunobased assays could not previously provide accurate measurement of serum estrogen concentrations in postmenopausal women, we have used validated mass spectrometry assays to measure the pharmacokinetics of serum estradiol and estrone during the 24 hours following the seventh daily application of 25 microg estradiol (Vagifem) and 1 g (0.625 mg) conjugated estrogens (Premarin) cream in 10 postmenopausal women in each group. Serum estradiol was increased on average by 5.4-fold from 3 to 17 pg/mL during the 24-hour period after daily administration of 25 microg estradiol or 1 g (0.625 mg) conjugated estrogens cream. Serum estrone, conversely, increased 150% with Vagifem and 500% with Premarin cream. The present data using validated, accurate, and sensitive mass spectrometry assays of estrogens show that the Vagifem pill and Premarin cream, after 1 week of daily treatment, cause an approximately fivefold increase in serum estradiol in postmenopausal women, thus indicating that the effects are unlikely to be limited to the vagina and that systemic actions are expected after application of these intravaginal estrogen preparations.

Two Estrogen-Related Variants in CYP19A1 and Endometrial Cancer Risk: A Pooled Analysis in the Epidemiology of Endometrial Cancer Consortium

Common variants in CYP19A1 (the A alleles of rs749292 and rs727479) have been associated with a 10% to 20% increase in circulating estrogen levels in postmenopausal women. We hypothesized that the presence of one or both A alleles in these single nucleotide polymorphisms (SNP) is associated with increased endometrial cancer risk. We tested this hypothesis in a large pooled analysis of 4,998 endometrial cancer cases and 8,285 controls from 10 studies in the Epidemiology of Endometrial Cancer Consortium. The majority of women (>66%) were whites, with smaller proportions of other races and ethnic groups (blacks, Asians, and Latinas) also included in this pooled analysis. Unconditional logistic regression was used to model the association between SNPs/haplotypes and endometrial cancer risk. Carrying the A allele of either of these SNPs was associated with an increased risk of endometrial cancer, with pooled odds ratios per allele of 1.14, 95% confidence interval of 1.09-1.21, and P = 7.1 x 10(-7) for rs749292, and odds ratio per allele of 1.08, 95% confidence interval of 1.02-1.14, and P = 0.009 for rs727479. For rs749292, these associations were generally stronger among women age >or=55 years. For both SNPs, risk increased with increasing body mass index, and for rs727479, this pattern seemed stronger among women age >or=55 years (P interaction = 0.007). The combination of A alleles in the two SNPs, either by direct count or by haplotype analysis, did not increase risk above that observed for the individual SNPs. Our study provides evidence that CYP19A1 genetic variation influences susceptibility to endometrial cancer, particularly among older and obese women.

Safety of Adjuvant Endocrine Therapy in Postmenopausal Women With Breast Cancer

The use of aromatase inhibitors (AIs) as adjuvant endocrine therapy for hormone-sensitive breast cancer is increasing, as these drugs are more effective than tamoxifen alone in improving disease-free survival in breast cancer patients-whether used in lieu of tamoxifen as upfront therapy or after tamoxifen treatment periods of 2 years or longer. AIs differ from tamoxifen in their mechanism of action, effectively suppressing estrogen levels in postmenopausal women to near-undetectable levels. AI-associated adverse events largely mimic menopausal symptoms, including hot flashes, losses in bone mineral density, gynecologic symptoms, and arthralgias. The AIs lack the infrequent but potentially serious adverse events associated with tamoxifen (eg, endometrial cancer, thromboembolic events, and stroke). Large randomized studies of AIs in the adjuvant setting have not demonstrated an adverse effect on lipids and cardiovascular health, but postmenopausal women receiving AIs are at risk for age-related changes in lipid parameters and an increased risk for cardiovascular events. To optimize the overall benefits of adjuvant endocrine therapy with an AI, patients should be monitored for bone loss and cardiovascular risk factors, and symptoms such as joint pain and vaginal dryness should be anticipated and managed proactively.

Effect of single-nucleotide polymorphisms in the CYP19 gene on response to Letrozole among breast cancer patients

22096 Background: Letrozole's effect in metastatic breast cancer (BC) patients was shown to be associated with a single nucleotide polymorphism (SNP) in the CYP19 aromatase gene. Two CYP19 polymorphisms; the 3'UTR rs10046 and IVS4(tct)± significantly correlate with serum estrogen levels in postmenopausal women. We evaluated their impact on response among BC patients treated with Letrozole. Methods: 70 BC patients treated with Letrozole with clinically evaluable disease (local stage III in 3, and metastatic in 67) were included. 65/67 metastatic patients, were treated with Tamoxifen before Letrozol (37-adjuvant, 28-first line for metastatic disease). DNA from whole blood was genotyped using DHLPC. Presence of WT or SNP was recorded. Correlation with tumor response (progressive, stable or responsive) in all patients and time to progression (TTP) from date of Letrozole start to progression were analyzed in 67/70 patients with metastatic disease. Results: Median age at diagnosis was 52 (range: 27–86). In 66, tumor was positive for estrogen receptor, in 2 it was negative and in additional 2 unknown. 28/70 (40%) carried the 3'UTR rs10046 wild type allele (WT). In the IVS4(tct)±, 3 genotypes, homozygous IVS4(tct)+, heterozygous IVS4(tct)± and homozygous IVS(tct)− were recorded with corresponding frequencies of 22/68 (32%), 30/68 (44%) and 15/68 (22%). These genotypes were not significantly associated with tumor response. However, median TTP was not reached at 30.4 months among carriers of IVS4 (tct)−/− allele compared with 14 and 12.7 months in heterozygots and homozygous (tct)+/+ respectively (p=0.02). Conclusion: homozygous delition of the (tct) at IVS4(tct)± of CYP19 is associated with longer TTP in patients with metastatic BC treated with Letrozole. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Novartis

Bone Mineral Density and Bone Turnover in Postmenopausal Women Treated for Breast Cancer

Chemotherapy and endocrine treatments for breast cancer are believed to increase risk of osteoporosis by causing early menopause in premenopausal women and by further depleting estrogen levels in postmenopausal women. Multivariate analyses were used to evaluate the contributions of 7 predictors (age, body mass index [BMI], family history of osteoporosis, months since menopause, past use of chemotherapy, and current use of tamoxifen or aromatase inhibitors) in explaining variability in bone mineral density (BMD) at the hip and the spine and bone turnover in 249 postmenopausal women who are breast cancer survivors. This report was an analysis of baseline data from a federally funded (1 R01 NR07743-01A1) intervention study on osteoporosis prevention. Mean age of the women was 58.5 years, and average BMI was 26.7 kg/m; 98% were white. All had measurable bone loss, 167 had chemotherapy, 76 were on tamoxifen, and 21 were on aromatase inhibitors. Women with higher BMI had higher BMD at the hip (P < .001) and the spine (P = .004). Women on tamoxifen had lower measures of bone formation (Alkphase B) (P < .001), suggesting less bone turnover, and higher BMD at the hip (P = .035). There was a trend for women who had received chemotherapy to have lower BMD at the spine (P = .06). The implications of these findings are discussed in the article.

An optimised, highly sensitive radioimmunoassay for the simultaneous measurement of estrone, estradiol and estrone sulfate in the ultra-low range in human plasma samples

Following the introduction of potent aromatase inhibitors for the treatment of breast cancer patients, highly sensitive methods have become mandatory to evaluate the influence of these drugs on plasma estrogen levels. Commercially available kits for estrogen measurements are not suitable for these kinds of evaluations due to their detection limits that are close to baseline estrogen levels in postmenopausal women. We describe here an optimised radioimmunoassay suitable for the simultaneous measurement of plasma estrone (E 1), estradiol (E 2) and estrone sulfate (E 1S) levels in the ultra-low range. Following incubation with [ 3H]-labelled estrogens as internal standards, crude estrogen fractions were separated by ether extraction. The E 1S fraction was hydrolysed with sulfatase followed by eluation on a Sephadex column. Free estrogens (E 1, E 2) were separated by chromatography (LH-20). Estrone and E 1S (following hydrolysis) were converted into E 2, and each estrogen fraction was measured by the same highly sensitive and specific radioimmunoassay using estradiol-6-(O-carboxymethyl)-oximino-2-(2-[ 125I]-iodo-histamine) as ligand. Although several purification steps were involved, the internal recovery values for tritiated estrogens were found to be 88%, 90%, and 49% for E 1, E 2 and E 1S, respectively. The intra-assay coefficient of variation was <5% for all recovery measurements. The detection limits were calculated following repeated blank measurements and found to be 1.14 pmol/L for E 1, 0.67 pmol/L for E 2, and 0.55 pmol/L for E 1S, respectively. The intra-assay coefficient of variation (CV) was found to be 3.4% for E 1, 5.1% for E 2 and 6.1% for E 1S, while the inter-assay CV was 13.6%, 7.6% and 7.5% for E 1, E 2, and E 1S, respectively. Considering normal plasma levels for E 2 (15 pmol/L), E 1 (80 pmol/L) and E 1S (400 pmol/L) in postmenopausal women, the method allows theoretically to detect suppression of plasma E 2, E 1 and E 1S levels by 95.5%, 98.6% and 99.9% when starting from average, normal postmenopausal levels. Thus, the method presented here is to our knowledge the currently most sensitive assay available for plasma estrogen measurements in the ultra-low range and, as such, a reliable tool for a proper evaluation of potent aromatase inhibitors and other potential drugs influencing on plasma estrogen levels.

236 RELATIONSHIP BETWEEN BONE TEXTURE AND LOCATION-SPECIFIC JOINT SPACE WIDTH IN KNEE RADIOGRAPHS OF SEVERELY OSTEOARTHRITIC PATIENTS

236 – Table I. Correlation between trabecular space (TrSp) & JSW(x=20.0%) and TrSp & JSW(x=27.5%) JSW(x=20.0%) JSW(x=27.5%) Covariate Adjustment β P-value Lower CI Upper CI β P-value Lower CI Upper CI Unadjusted 0.217 0.218 0.000 0.000 0.243 0.166 0.000 0.000 Gender 0.262 0.023 0.000 0.000 0.246 0.033 0.000 0.000 Gender & BMI 0.313 0.008 0.000 0.000 0.304 0.011 0.000 0.000 Abstract 236 – Table II. Correlation between free ends (FE) & JSW(x=20.0%) and FE & JSW(x=27.5%).236 – Table II. Correlation between free ends (FE) & JSW(x=20.0%) and FE & JSW(x=27.5%). JSW(x=20.0%) JSW(x=27.5%) Covariate Adjustment β P-value Lower CI Upper CI β P-value Lower CI Upper CI Unadjusted -0.249 0.156 -0.012 0.002 -0.252 0.151 -0.009 0.001 BMI -0.370 0.027 -0.014 -0.001 -0.397 0.018 -0.011 -0.001 Age & BMI -0.400 0.021 -0.011 -0.001 -0.400 0.021 -0.011 -0.001 Figure 1. Placement of locater-rule endpoints on anatomic landmarks in knee radiograph for identification of subchondral regions of interest. of significance were identified between the JSW(x=20.0%) and JSW(x=27.5%) sites. No significant correlations between either JSW(x=20.0%) or JSW(x=27.5%) and each of BsTv, BvTv, CI, NL and TrTh were revealed (p>0.05). Conclusions: In the subchondral bone of the tibia, lower JSW(x) measures appear to be associated with larger values in trabecular FE and lower amounts of TrSp after accounting for gender, age and BMI. We anticipated that BMI and age would explain some variability in FE since older individuals tend to have higher BMI and more severe JSW narrowing. On the other hand, smaller JSW(x) correlating with lower TrSp after gender and BMI adjustment supports the proposition that severely OA patients with more JSW narrowing may have higher subchondral bone density. The influence of BMI may be similar to that formerly explained, while gender effects may be due to reduced estrogen levels in postmenopausal women. While minimum JSW may act as a surrogate measure for cartilage thickness, we further propose that digital assessment of JSW(x) could allow estimation of subchondral bone texture properties.