16 α-Hydroxyestrone induced adduct generate high affinity autoantibodies in SLE.

PURPOSE: Increased 16 α-hydroxyestrone (16 α-OHE1) and autoantibodies against histone H1 (H1) have been well described in systemic lupus erythematosus (SLE), but the combination effects of 16 α-OHE1 and H1 remains unclear. Here, we tried to assess the affinity and binding specificity of SLE autoantibodies against the 16 α-OHE1-H1 adduct. IgG was induced against this adduct and was also used as immunochemical probe for the estimation of 16 α-OHE1 in the serum of SLE patients. MATERIALS AND METHODS: The affinity and binding specificities of SLE autoantibodies against 16 α-OHE1-H1 were determined by direct binding and inhibition ELISA as well as quantitative precipitation titration in 60 patients and 30 control subjects. RESULTS: Purified SLE autoantibodies showed greater recognition to 16 α-OHE1-H1 over H1 (p < 0.05) or 16 α-OHE1 (p < 0.001). The relative affinity of SLE autoantibodies for 16 α-OHE1-H1, H1 and 16 α-OHE1 was 1.41 × 10-7, 1.31 × 10-6, and 1.03 × 10-6, respectively. The concentration of 16 α-OHE1 in the sera of SLE patients was significantly higher than controls (p < 0.05) as estimated by anti-16 α-OHE1-H1 antibodies. CONCLUSIONS: High affinity of 16 α-OHE1-H1 with SLE autoantibodies might suggest an antigenic role of this adduct in the production of these autoantibodies. The anti-16 α-OHE1-H1 antibody is a good immunochemical probe to measure 16 α-OHE1 in different SLE sera.

Depression enhanced the production of autoantibodies against 16α­hydroxyestrone-estrogen receptor adduct in breast cancer.

Mentally depressed breast cancer (MDBC) patients expressed estrogen receptor (ER) and 16α­hydroxyestrone (16α­OHE1) is directly responsible for causing breast cancer (BC). This study aimed to identify whether depression in breast cancer patients enhanced the production of autoantibodies against 16α­OHE1-ER adduct in breast cancer patients. The antibodies in the serum of 65 breast cancer patients (including 35 MDBC) and 40 control subjects were screened by direct binding, inhibition enzyme-linked immunosorbent assay (ELISA), and quantitative precipitin titration. Competition ELISA was also utilized for the estimation of 16α­OHE1 in the serum of 30 cancer patients. Autoantibodies from MDBC showed strong recognition to 16α­OHE1-ER in comparison to overall breast cancer patients (p < 0.05) and control subjects (p < 0.001). Although breast cancer sera showed high binding to 16α­OHE1-ER in comparison to ER (p < 0.05) or 16α­OHE1 (p < 0.001), the relative affinities of autoantibodies for 16α­OHE1-ER were found to be 1.38 × 10-7 and 1.23 × 10-7 for breast cancer and MDBC patients respectively. No significant difference, either in the level of 16α­OHE1 or 2­hydroxyestrone/16α­OHE1 ratio, was observed in the serum of cancer patients compared with controls, although inflammatory cytokines (IL-6, TNF-α) were significantly high in these patients. Depression in breast cancer patients augments the production of autoantibodies against 16α­OHE1-ER through the generation of inflammatory conditions. Depression in these patients increased the release of pro-inflammatory cytokines that generate more autoantibodies and show strong binding with 16α­OHE1-ER.

Effect of Dietary Flaxseed Intake on Circulating Sex Hormone Levels among Postmenopausal Women: A Randomized Controlled Intervention Trial.

Lignan intake, and its richest food source, flaxseed, have been associated with reduced breast cancer risk. Endogenous sex hormones, such as estrogens, play a role in breast cancer development, and lignans may alter these sex hormone levels. To assess the effect of flaxseed on circulating sex hormones, a randomized controlled trial was conducted among 99 postmenopausal women in Toronto, Canada. The intervention arm consumed 2 tablespoons (15 g) of ground flaxseed daily for 7 weeks; the control arm maintained usual diet. Baseline and week 7 concentrations of 14 serum sex hormones were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and immunoassay, and serum enterolignans (lignan biomarker) using LC-MS/MS. Intervention effects on sex hormone levels were assessed using analysis of covariance. Serum enterolignans increased among the flaxseed arm (+516%). Women consuming flaxseed (vs. controls) had increased serum 2-hydroxyestrone [treatment effect ratio (TER) = 1.54; 95% CI: 1.18-2.00] and 2:16α-hydroxyestrone ratio (TER =1.54; 95% CI: 1.15-2.06); effects on other hormones were not statistically significant. Within the flaxseed arm, change in enterolignan level was positively correlated with changes in 2-hydroxyestrone and 2:16α-hydroxyestrone ratio, and negatively with prolactin. Findings suggest flaxseed affects certain circulating sex hormone levels with possible implications for future breast cancer prevention research.

Sex Hormone Metabolism and Threatened Abortion.

BACKGROUND The aim of this study was to evaluate changes in sex hormone metabolism in patients with threatened miscarriage. MATERIAL AND METHODS We recruited 73 women in early pregnancy (6-8 weeks of gestation) and divided them into the following 2 groups based on whether they had vaginal bleeding: group A (n=34), the threatened abortion group; and group B (n=39), the normal pregnancy group. Human chorionic gonadotrophin (hCG), estradiol (E2), progesterone (P4), and testosterone (T) serum levels were tested and sex hormone metabolites in the urine were detected using gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). As the control, data for sex hormones and their metabolites were obtained in normal women of childbearing age without pregnancy (group C: n=23). RESULTS E2 and T serum levels were lower in women with threatened miscarriage (group A). Estrone (E1), E2, estriol (E3), 16α-hydroxyestrone (16α-OHE1), 4-methoxyestrone (4-MeOE1), 2-hydroxyestradiol (2-OHE2), and 4-methoxyestradiol (4-MeOE2) levels were significantly lower in group A (P=0.001, 0.003, 0.009, 0.001, 0.012, 0.032, and 0.047, respectively.). Urine levels of dehydroepiandrosterone (DHEA), androstenedione (A2), and the metabolite of (A2) were also significantly lower in group A (P=0.007, 0.009, and 0.011, respectively). The 2-OHE1/E1, 4-OHE1/E1, 2-MeOE1/E1, and 2-MeOE2/E2 ratios were lower in group B, whereas the 2-OHE2/E2, 4-OHE2/E2, and 4-MeOE2/E2 ratios were dramatically lower in all pregnant women (groups A and B) than in group C. CONCLUSIONS Deficiency in DHEA and abnormal levels of sex hormone metabolites may cause a reduction in the activity of estrogens in women with threatened abortion. These alterations may result in bleeding during the first trimester of pregnancy.

A randomized, placebo-controlled trial of diindolylmethane for breast cancer biomarker modulation in patients taking tamoxifen.

PURPOSE: Diindolylmethane (DIM), a bioactive metabolite of indole-3-carbinol found in cruciferous vegetables, has proposed cancer chemoprevention activity in the breast. There is limited evidence of clinically relevant activity of DIM or long-term safety data of its regular use. A randomized, double-blind, placebo-controlled trial was conducted to determine the activity and safety of combined use of BioResponse DIM® (BR-DIM) with tamoxifen. METHODS: Women prescribed tamoxifen (n = 130) were randomly assigned oral BR-DIM at 150 mg twice daily or placebo, for 12 months. The primary study endpoint was change in urinary 2/16α-hydroxyestrone (2/16α-OHE1) ratio. Changes in 4-hydroxyestrone (4-OHE1), serum estrogens, sex hormone-binding globulin (SHBG), breast density, and tamoxifen metabolites were assessed. RESULTS: Ninety-eight women (51 placebo, 47 DIM) completed intervention; compliance with treatment was >91%. BR-DIM increased the 2/16α-OHE1 ratio (+3.2 [0.8, 8.4]) compared to placebo (-0.7 [-1.7, 0.8], P < 0.001). Serum SHBG increased with BR-DIM compared to placebo (+25 ± 22 and +1.1 ± 19 nmol/L, respectively). No change in breast density measured by mammography or by MRI was observed. Plasma tamoxifen metabolites (endoxifen, 4-OH tamoxifen, and N-desmethyl-tamoxifen) were reduced in women receiving BR-DIM versus placebo (P < 0.001). Minimal adverse events were reported and did not differ by treatment arm. CONCLUSION: In patients taking tamoxifen for breast cancer, daily BR-DIM promoted favorable changes in estrogen metabolism and circulating levels of SHBG. Further research is warranted to determine whether BR-DIM associated decreases in tamoxifen metabolites, including effects on endoxifen levels, attenuates the clinical benefit of tamoxifen. TRIAL REGISTRATION: ClinicalTrials.gov NCT01391689.

Relation of Serum Estrogen Metabolites with Terminal Duct Lobular Unit Involution Among Women Undergoing Diagnostic Image-Guided Breast Biopsy.

Higher levels of circulating estrogens and estrogen metabolites (EMs) have been associated with higher breast cancer risk. In breast tissues, reduced levels of terminal duct lobular unit (TDLU) involution, as reflected by higher numbers of TDLUs and acini per TDLU, have also been linked to elevated breast cancer risk. However, it is unknown whether reduced TDLU involution mediates the risk associated with circulating EMs. In a cross-sectional analysis of 94 premenopausal and 92 postmenopausal women referred for clinical breast biopsy at an academic facility in Vermont, we examined the associations of 15 EMs, quantified using liquid chromatography-tandem mass spectrometry, with the number of TDLUs and acini count/TDLU using zero-inflated Poisson regression with a robust variance estimator and ordinal logistic regression models, respectively. All analyses were stratified by menopausal status and adjusted for potential confounders. Among premenopausal women, comparing the highest vs. the lowest tertiles, levels of unconjugated estradiol (risk ratio (RR) = 1.74, 95 % confidence interval (CI) = 1.06-2.87, p trend = 0.03), 2-hydroxyestrone (RR = 1.74, 95 % CI = 1.01-3.01, p trend = 0.04), and 4-hydroxyestrone (RR = 1.74, 95 % CI = 0.99-3.06, p trend = 0.04) were associated with significantly higher TDLU count. Among postmenopausal women, higher levels of estradiol (RR = 2.09, 95 % CI = 1.01-4.30, p trend = 0.04) and 16α-hydroxyestrone (RR = 2.27, 95 % CI = 1.29-3.99, p trend = 0.02) were significantly associated with higher TDLU count. Among postmenopausal women, higher levels of EMs, specifically conjugated estrone and 2- and 4-pathway catechols, were also associated with higher acini count/TDLU. Our data suggest that higher levels of serum EMs are generally associated with lower levels of TDLU involution.

Metabolomic analysis of serum from obese adults with hyperlipemia by UHPLC-Q-TOF MS/MS.

The prevalence of obesity has dramatically increased and poses a major threat to human health. Obesity often accompanies hyperlipemia, which is strongly related to the occurrence and development of obesity-related chronic diseases. Differences in metabolomic profiling of serum between obese (with hyperlipemia) and normal-weight men (n = 30 in each group) were investigated using ultrahigh-pressure liquid chromatography-quadrupole-time of flight mass spectrometry (UHPLC-Q-TOF MS/MS) and partial least-squares-discriminant analysis (PLS-DA). Obese men showed higher levels of weight, body mass index, fat mass, systolic blood pressure, fasting plasma glucose, triglyeride, total cholesterol, insulin, HOMA-IR and high-sensitivity CRP. Obese and normal-weight groups were clearly discriminated from each other on a PLS-DA score plot and nine major metabolites contributing to the discrimination were assigned, including increased 2-octenoylcarnitine, eicosadienoic acid, 12-hydroperoxyeicosatetraenoic acid, 4-hydroxyestrone sulfate, lysoPE[18:1(11Z)/0:0], thromboxane B2 and pyridinoline and decreased vitamin D3 glucosiduronate and 9,10-DHOME. These metabolites were associated with lipid metabolism and obesity-related diseases, and reflected the metabolic differences between normal and obese men, which may be important for future clinical diagnosis, treatment and assessment of the therapeutic effect on obesity-related chronic disease.

Measurement of serum estrogen and estrogen metabolites in pre- and postmenopausal women with osteoarthritis using high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry

Although 17β-estradiol (E2) deficiency has been linked to the development of osteoarthritis (OA) in middle-aged women, there are few studies relating other estrogens and estrogen metabolites (EMs) to this condition. We developed a high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method to measure the levels of six EMs (i.e., estrone, E2, estriol, 2-hydroxyestrone, 2-hydroxyestradiol, and 16a-hydroxyestrone) in healthy pre- and postmenopausal women and women with OA. This method had a precision ranging from 1.1 to 3.1% and a detection limit ranging from 10 to 15 pg. Compared to healthy women, serum-free E2 was lower in the luteal and postmenopausal phases in women with OA, and total serum E2 was lower in postmenopausal women with OA. Moreover, compared to healthy women, total serum 2-hydroxyestradiol was higher in postmenopausal women with OA and total serum 2-hydroxyestrone was lower in both the luteal and follicular phases in women with OA. In conclusion, our HPLC-ESI-MS/MS method allowed the measurement of multiple biochemical targets in a single assay, and, given its increased cost-effectiveness, simplicity, and speed relative to previous methods, this method is suitable for clinical studies.

Measurement of serum estrogen and estrogen metabolites in pre- and postmenopausal women with osteoarthritis using high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry.

Although 17ß-estradiol (E2) deficiency has been linked to the development of osteoarthritis (OA) in middle-aged women, there are few studies relating other estrogens and estrogen metabolites (EMs) to this condition. We developed a high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method to measure the levels of six EMs (i.e., estrone, E2, estriol, 2-hydroxyestrone, 2-hydroxyestradiol, and 16a-hydroxyestrone) in healthy pre- and postmenopausal women and women with OA. This method had a precision ranging from 1.1 to 3.1% and a detection limit ranging from 10 to 15 pg. Compared to healthy women, serum-free E2 was lower in the luteal and postmenopausal phases in women with OA, and total serum E2 was lower in postmenopausal women with OA. Moreover, compared to healthy women, total serum 2-hydroxyestradiol was higher in postmenopausal women with OA and total serum 2-hydroxyestrone was lower in both the luteal and follicular phases in women with OA. In conclusion, our HPLC-ESI-MS/MS method allowed the measurement of multiple biochemical targets in a single assay, and, given its increased cost-effectiveness, simplicity, and speed relative to previous methods, this method is suitable for clinical studies.

Circulating estrogen metabolites and risk of breast cancer in postmenopausal women.

BACKGROUND: It has been hypothesized that predominance of the 2-hydroxylation estrogen metabolism pathway over the 16α-hydroxylation pathway may be inversely associated with breast cancer risk. METHODS: We examined the associations of invasive breast cancer risk with circulating 2-hydroxyestrone (2-OHE1), 16α-hydroxyestrone (16α-OHE1), and the 2-OHE1:16α-OHE1 ratio in a case-control study of postmenopausal women nested within two prospective cohorts: the New York University Women's Health Study (NYUWHS) and the Northern Sweden Mammary Screening Cohort (NSMSC), with adjustment for circulating levels of estrone, and additional analyses by tumor estrogen receptor (ER) status. Levels of 2-OHE1 and 16α-OHE1 were measured using ESTRAMET 2/16 assay in stored serum or plasma samples from 499 incident breast cancer cases and 499 controls, who were matched on cohort, age, and date of blood donation. RESULTS: Overall, no significant associations were observed between breast cancer risk and circulating levels of 2-OHE1, 16α-OHE1, or their ratio in either cohort and in combined analyses. For 2-OHE1, there was evidence of heterogeneity by ER status in models adjusting for estrone (P ≤ 0.03). We observed a protective association of 2-OHE1 with ER+ breast cancer [multivariate-adjusted OR for a doubling of 2-OHE1, 0.67 (95% confidence interval [CI], 0.48-0.94; P = 0.02)]. CONCLUSIONS: In this study, higher levels of 2-OHE1 were associated with reduced risk of ER+ breast cancer in postmenopausal women after adjustment for circulating estrone. IMPACT: These results suggest that taking into account the levels of parent estrogens and ER status is important in studies of estrogen metabolites and breast cancer.

Multi-nutrient supplement improves hormone ratio associated with cancer risk.

BACKGROUND: Gynecological cancers are among the most common in women and are directly related to a variety of hormonal factors. One potential risk factor associated with developing a gynecological malignancy is the ratio of two hormone metabolites, 2-Hydroxyestrone (2-HE) and 16alpha-Hydroxyestrone (16alpha-HE). A number of botanical constituents such as indoles, flavonoids, and resveratrol have been shown to have a favorable effect on the metabolic pathways that affect this ratio. The present study was designed to evaluate if a multi-nutrient supplement containing targeted botanical constituents would affect the 2-HE/16 alpha-HE ratio in middle-aged women. METHODS: A retrospective analysis was performed on 76 female patients (mean age 54 years) who received 2-HE/16 alpha-HE ratio assessments at two separate time points. The ratio assessment was part of standard care for women who presented with risk indicators associated with a high proliferative state. All patients who completed pre and post assessments were included. Sixty-five of the patients received a multi-nutrient supplement, Lucentia Peak, during the study period. Eleven patients chose not to take the supplement, but did receive ratio assessments at similar time points as the treatment group, allowing for between group comparisons. Paired t-tests were used to compare the changes in the 2-HE and 16alpha-HE measures as well as their ratio, both within groups and between groups. RESULTS: The results demonstrated a significant increase in the 2-HE/16alpha-HE ratio in the treated group (pre 0.38 to post 0.57, p<0.0001), and was significantly different (p=0.02) compared to the change in the control group (pre 0.65 to post 0.64). This change appears to be mediated primarily by an increase in the 2-HE level. Individually, 54 patients given Lucentia Peak had increased ratios while 11 patients had a decrease. In the control group, 3 patients had an increase in their ratio and 8 patients had a decrease. CONCLUSIONS: The results demonstrated that women receiving the Lucentia Peak multi-nutrient supplement had significant increases in their 2-HE:16alpha-HE ratio, which appears to be mediated primarily by increasing the 2-HE levels. These results suggest further research on phytonutrients that might positively affect estrogen metabolism is warranted.

Postmenopausal circulating levels of 2- and 16α-hydroxyestrone and risk of endometrial cancer.

BACKGROUND: It has been suggested that the relative importance of oestrogen-metabolising pathways may affect the risk of oestrogen-dependent tumours including endometrial cancer. One hypothesis is that the 2-hydroxy pathway is protective, whereas the 16α-hydroxy pathway is harmful. METHODS: We conducted a case-control study nested within three prospective cohorts to assess whether the circulating 2-hydroxyestrone : 16α-hydroxyestrone (2-OHE1 : 16α-OHE1) ratio is inversely associated with endometrial cancer risk in postmenopausal women. A total of 179 cases and 336 controls, matching cases on cohort, age and date of blood donation, were included. Levels of 2-OHE1 and 16α-OHE1 were measured using a monoclonal antibody-based enzyme assay. RESULTS: Endometrial cancer risk increased with increasing levels of both metabolites, with odds ratios in the top tertiles of 2.4 (95% CI=1.3, 4.6; P(trend)=0.007) for 2-OHE1 and 1.9 (95% CI=1.1, 3.5; P(trend)=0.03) for 16α-OHE1 in analyses adjusting for endometrial cancer risk factors. These associations were attenuated and no longer statistically significant after further adjustment for oestrone or oestradiol levels. No significant association was observed for the 2-OHE1 : 16α-OHE1 ratio. CONCLUSION: Our results do not support the hypothesis that greater metabolism of oestrogen via the 2-OH pathway, relative to the 16α-OH pathway, protects against endometrial cancer.

A prospective phase II study of 2-methoxyestradiol administered in combination with bevacizumab in patients with metastatic carcinoid tumors.

PURPOSE: Angiogenesis inhibition has emerged as a potentially promising treatment strategy for neuroendocrine tumors. 2-Methoxyestradiol (2ME2; Panzem(®)) is a natural derivative of estradiol with demonstrated anti-angiogenic activity in animal models. We performed a prospective, phase II study of 2ME2, administered in combination with bevacizumab, in patients with advanced carcinoid tumors. METHODS: Thirty-one patients with advanced carcinoid tumors were treated with 2ME2, administered orally at a dose of 1,000 mg four times daily. Patients also received bevacizumab 5 mg/kg intravenously every 2 weeks. Patients were observed for evidence of toxicity, tumor response, and survival. RESULTS: The combination of 2ME2 and bevacizumab was relatively easily tolerated and was associated with anticipated toxicities for these two agents. No confirmed radiologic responses (by RECIST) were observed. However, 68% of the radiologically evaluable patients experienced at least some degree of tumor reduction, and the median progression-free survival (PFS) time was 11.3 months. CONCLUSION: 2ME2 and bevacizumab can be safely administered to patients with advanced carcinoid tumors. While major tumor regression was not observed with this regimen, the encouraging median progression-free survival time suggests that this regimen has some degree of antitumor activity and supports the further investigation of angiogenesis inhibitors in this disease.

Dietary fiber and serum 16α-hydroxyestrone, an estrogen metabolite associated with lower systolic blood pressure.

OBJECTIVE: We recently identified an inverse relation between systolic blood pressure (SBP) and serum 16α-hydroxyestrone, a metabolite of 17ß-estradiol, in postmenopausal women. Formation of 16α-hydroxyestrone is catalyzed primarily by CYP1A2, a cytochrome P450 enzyme. The objective of this study was to evaluate the relations between known modifiers of CYP1A2 activity and serum 16α-hydroxyestrone in postmenopausal women. We hypothesized that fruits, vegetables, and grains, which contain more soluble fiber (a known inducer of CYP1A2) as a proportion of total fiber, would be more positively associated with serum 16α-hydroxyestrone than legumes, which contain less soluble fiber as a proportion of total fiber. METHODS: Serum from a population-based sample of 42 postmenopausal women 55 to 69 y of age living in Cook County, Illinois, was assayed for 16α-hydroxyestrone using mass spectrometry. Ordinal logistic regression was used to evaluate the cross-sectional relation between dietary fiber and serum 16α-hydroxyestrone after adjusting for multiple covariates. RESULTS: Compared with dietary fiber from legumes, dietary fiber from fruits and vegetables was associated with a greater log odds (B=0.201, P=0.036) of having higher serum concentrations of 16α-hydroxyestrone. The log odds of having higher serum concentrations of 16α-hydroxyestrone was also lower in African-American women (B=-2.300, P=0.030) compared with white women. CONCLUSION: These results are consistent with previous studies demonstrating a negative relation between SBP and dietary fruits and vegetables and a positive relation between African-American race and SBP. Further research is needed regarding dietary factors that may influence the serum concentration of 16α-hydroxyestrone.

Serum concentrations of selected endogenous estrogen and estrogen metabolites in pre- and post-menopausal Chinese women with osteoarthritis.

The purpose of this study was to investigate whether serum levels of selected endogenous estrogens and their metabolites are involved in the pathogenesis of osteoarthritis in pre- and post-menopausal women with osteoarthritis. Sixty-four patients with osteoarthritis (OA) of the knee, 48 patients with rheumatoid arthritis (RA) of the knee, and 48 healthy women were included in this study. Serum concentrations of estradiol and estrogen metabolites, such as 2- hydroxyestrone, 2-hydroxyestradiol, and 16α-hydroxyestrone, were measured by high performance liquid chromatography-mass spectrometry. Our results show that the serum concentrations of free estradiol and total 2-hydroxyestrone were significantly lower in pre-menopausal women with OA compared to the levels detected in the control groups (RA and healthy women). While serum concentrations of free and total estradiol in post-menopausal women with OA was significantly decreased compared to those of the control groups, the level of total 2-hydroxyestradiol significantly increased in postmenopausal women. Furthermore, the total 2-hydroxyestrone concentration positively correlated with the total estradiol level in pre-menopausal women with OA. In addition, the total 2- hydroxyestradiol level positively correlated with free and total estradiol levels in post-menopausal women with OA. In conclusion, estradiol and estrogen metabolites, including 2-hydroxyestrone and 2-hydroxyestradiol, were found in the sera of pre- and post-menopausal women with OA. Except for free and total estradiol deficiency, a decreased serum level of total 2- hydroxyestrone in pre-menopausal women and an increased total 2-hydroxyestradiol level in post-menopausal women with OA may also correlate with the pathogenesis of female OA.

Circulating estrogen metabolites and risk for breast cancer in premenopausal women.

BACKGROUND: It has been proposed that a shift toward 2-hydroxyestrone from 16alpha-hydroxyestrone metabolic pathway may be inversely associated with breast cancer risk because 2-hydroxyestrone is thought to be less genotoxic and estrogenic than 16alpha-hydroxyestrone. METHODS: We examined the associations of invasive breast cancer risk with circulating 2-hydroxyestrone, 16alpha-hydroxyestrone, and the 2-hydroxyestrone:16alpha-hydroxyestrone ratio in a case-control study on premenopausal women nested within a prospective cohort the New York University Women's Health Study. The serum levels of 2-hydroxyestrone and 16alpha-hydroxyestrone were measured in 377 incident premenopausal breast cancer cases and 377 premenopausal controls, who were matched on age at enrollment, number and dates of blood donations, and day and phase of menstrual cycle. RESULTS: Overall, no significant associations were observed between breast cancer risk and serum levels of 2-hydroxyestrone, 16alpha-hydroxyestrone, or their ratio. The 2-hydroxyestrone:16alpha-hydroxyestrone ratio was positively associated with risk for estrogen receptor-positive breast cancer in the analyses controlling for matching factors. However, the association was attenuated and not significant after adjustment for potential confounders (odds ratio for the highest versus the lowest quartile, 2.15; 95% CI, 0.88-5.27; P(trend) = 0.09). CONCLUSIONS: The results of the current study do not support the hypothesis that a metabolic shift from 16alpha-hydroxyestrone toward 2-hydroxyestrone in premenopausal women is associated with reduced risk for breast cancer. The association between the 2-hydroxy:16alpha-hydroxyestrone ratio and estrogen receptor-positive breast cancer needs to be explored in future studies.

Serum estrogen metabolites and systolic blood pressure among middle-aged and older women and men.

BACKGROUND: Hypertension is more common among men at younger ages and among women after age 60, suggesting a possible link between endogenous estrogens and systolic blood pressure (SBP). We tested whether serum 17beta-estradiol (E(2)) or any of its metabolites were associated with SBP among middle-aged and older adults. METHODS: Using a cross-sectional study design, we examined data from a population-based sample of 98 adults living in Cook County, Illinois. Age ranged between 55 and 69 years and body mass index (BMI) ranged between 19.8 and 50.6 kg/m(2). Serum was analyzed for 17beta-E(2) and 14 estrogen metabolites (EMs) using mass spectrometry. SBP was measured using a tonometric device that records a pulse wave at the radial artery. Demographic and health history information were obtained via questionnaires. RESULTS: Univariate analysis revealed an inverse relationship between SBP and both natural log (ln) 16alpha-hydroxyestrone (OHE(1)) (r = -0.360, P < 0.05) and ln 16-ketoestradiol (ketoE(2)) (r = -0.360, P < 0.05) among women but not men. No significant correlations were found between SBP and 17beta-E(2) in either sex. In multivariate analysis which adjusted for age, race, ethnicity, BMI, and use of cardiovascular medications, ln 16alpha-hydroxyestrone (16alpha-OHE(1)) (B = -5.3, s.e. = 2.1, P < 0.05) and ln 16-ketoE(2) (B = -4.7, s.e. = 1.9, P < 0.05) continued to be negatively associated with SBP among postmenopausal women. CONCLUSIONS: These data suggest that serum 16alpha-OHE(1) or 16-ketoE(2) may be important for vascular health among postmenopausal women but not among similarly aged men.

Activity of 2 methoxyestradiol (Panzem NCD) in advanced, platinum-resistant ovarian cancer and primary peritoneal carcinomatosis: a Hoosier Oncology Group trial.

BACKGROUND: 2-Methoxyestradiol (Panzem, 2ME2) is an endogenous metabolite of estradiol that destabilizes microtubules and exerts anti-angiogenic properties. This study was conducted to determine the activity and safety of 2ME2 administered as a NanoCrystal dispersion (NCD) formulation in patients with recurrent, platinum-resistant epithelial ovarian cancer (EOC). METHODS: Eligible patients had relapsed, platinum-resistant or refractory EOC with measurable or detectable disease. There was no limit on the number of prior treatment regimens. 2ME2 NCD 1000 mg orally four times daily (q.i.d.) was administered continuously during 4 week cycles. The primary endpoint was objective response rate (ORR). Secondary endpoints were assessment of toxicity, rate of clinical benefit defined as the number of patients experiencing an objective response, a CA125 response or stable disease (SD) >3 months, mean change in CA-125, progression-free survival (PFS), and pharmacokinetic analyses of 2ME2. RESULTS: Eighteen patients were enrolled. Median age was 65.5 (range 40-73). Patients had received a median of five prior treatments. The most common adverse events were fatigue (78%), nausea (78%), diarrhea (39%), neuropathy (50%), edema (39%), and dyspnea (44%), the majority being grade 1-2. There were no objective responses, but seven patients had SD as best response. Of those, two patients had SD for greater than 12 months. The rate of clinical benefit was 31.3%. Fairly stable plasma levels of 2ME2 ranging within the predicted therapeutic window were observed. CONCLUSIONS: The NCD formulation of 2ME2 is well tolerated in patients with heavily pretreated EOC. Few of these heavily pretreated patients had sustained stable disease.

Ethnicity, body size, and estrogen levels in postmenopausal Hispanic and non-Hispanic white women.

BACKGROUND: Hispanic women are at lower risk for incident breast cancer, but the reasons for this lower risk are unknown. Among postmenopausal women, breast cancer risk is inversely associated with circulating levels of 2-hydroxyestrone but directly associated with levels of 16alpha-hydroxyestrone, according to most studies. Likewise, according to most research, the ratio of 2-hydroxyestrone/16alpha-hydroxyestrone is, therefore, inversely associated with breast cancer risk. METHODS: We measured levels of these two circulating estrones as well as estradiol in 40 Hispanic women and 40 non-Hispanic white women who were all postmenopausal and not taking hormones. RESULTS: Compared with non-Hispanic white women, Hispanic women had 69% higher circulating levels of 2-hydroxyestrone (p = 0.04), and 10% lower levels of 16alpha-hydroxyestrone (p = 0.09). Consequentially, Hispanic women had more favorable estrogen profiles than non-Hispanic white women, with an 89% higher 2:16 ratio (p = 0.01). This finding was not substantially affected by adjustment for other breast cancer risk factors, including matching on body mass index (BMI). CONCLUSIONS: This ethnic difference in estrogen profile requires further research to establish whether there is a causal relationship to breast cancer risk that may, at least partially, explain why postmenopausal Hispanic women have a lower incidence of breast cancer.

Oestrogen metabolites in relation to isoprostanes as a measure of oxidative stress.

OBJECTIVE: Oestradiol (E2) and its metabolites 2-hydroxyoestrone (2-OHE1) and 16alpha-hydroxyoestrone (16alpha-OHE1) are thought to curtail the greater oxidative stress found in the development and progression of disease conditions including atherosclerosis. We related oestrogen levels to F(2a)-isoprostane levels, a biomarker of oxidative stress. DESIGN AND PARTICIPANTS: Data were obtained from 1647 women, aged 47-57 years, participating in the fifth annual follow-up of the Study of Women's Health Across the Nation (SWAN), a study of the menopausal transition. MEASUREMENTS: Serum E2 and urinary 2-OHE1 and 16alpha-OHE1 concentrations were determined by enzyme-linked immunosorbent assay (ELISA) and urinary F(2a)-isoprostanes were measured by enzyme immunoassay (EIA). RESULTS: F(2a)-isoprostane concentrations were elevated in women who smoked, a behaviour associated with increased oxidative stress, but not in stages of the natural menopause. Mean F(2a)-isoprostane concentrations among pre- and postmenopausal women who smoked were 1082 and 1064 pg/ml, respectively, values double those in pre- (343 pg/ml) and postmenopausal (379 pg/ml) nonsmoking women. 2-OHE1 and F(2a)-isoprostane concentrations were positively and highly correlated (partial correlations rho(Y|X) = 0.44 and rho(Y|X) = 0.43 in pre- and postmenopausal women, respectively). Similarly, 16alpha-OHE1 concentrations were positively and highly correlated with F(2a)-isoprostane concentrations (rho(Y|X) = 0.52 and rho(Y|X) = 0.59 in pre- and postmenopausal women, respectively). E2 was significantly correlated with F(2a)-isoprostanes only in postmenopausal women (rho(Y|X) = 0.20). Associations were adjusted for age, body mass index (BMI), race/ethnicity, lipids, physical activity level and alcohol consumption. CONCLUSIONS: This study does not support the commonly held hypothesis that levels of endogenous E2 or its oestrone metabolites favourably modify oxidative stress by decreasing F2(a)-isoprostane levels.