Menstrual Phase and Menopausal Status Classification of Benign Breast Tissue Using Hormone-Regulated Gene Expression and Histomorphology: A Validation Study

BACKGROUND

The validation of breast cancer risk biomarkers in benign breast samples (BBS) is a long-sought goal, hampered by the fluctuation of gene and protein expression with menstrual phase (MP) and menopausal status (MS). Previously, we identified hormone-related gene expression and histomorphology parameters to classify BBS by MS/MP. We now evaluate both together, to validate our prior results.

PATIENTS AND METHODS

BBS were obtained from consenting women (86 premenopausal, 55 postmenopausal) undergoing reduction mammoplasty (RM) or contralateral unaffected breast (CUB) mastectomy. MP/MS was defined using classical criteria for menstrual dates and hormone levels on the day of surgery. BBS gene expression was measured with reverse transcription quantitative polymerase chain reaction (RT-qPCR) for three luteal phase (LP) genes (TNFSF11, DIO2, MYBPC1) and four menopausal genes (PGR, GREB1, TIFF1, CCND1). Premenopausal samples were classified into LP or non-LP, using published histomorphology parameters. Logistic regression and receiver-operator curve analysis was performed to assess area under the curve (AUC) for prediction of MP/MS.

RESULTS

In all 131 women, menopausal genes plus age > 50 years predicted true MS [AUC 0.93, 95% confidence interval (CI) 0.89, 0.97]. Among premenopausal women, high TNFSF11 expression distinguished non-LP from LP samples (AUC 0.80, 95% CI 0.70, 0.91); the addition of histomorphology improved the prediction nonsignificantly (AUC 0.87, 95% CI 0.78, 0.96). In premenopausal subsets, addition of histomorphology improved LP prediction in RM (AUC 0.95, 95% CI 0.87, 1.0), but not in CUB (0.84, 95% CI 0.72, 0.96).

CONCLUSIONS

Expression of five-gene set accurately predicts menopausal status and menstrual phase in BBS, facilitating the development of breast cancer risk biomarkers using large, archived sample repositories.

HPLC fractionation with immunoassay of steroids from nipple aspirate fluid

Fractionation of steroids allows for multiple assays to be run on a single low volume liquid biopsy, whereas performing the same number of assays without fractionation would require increasing the sample volume by dilution, rendering the concentration of steroids below the level of detection for most, if not all, downstream assays. Briefly, steroids are extracted from a biofluid sample using solvent phase extraction to separate the aqueous (conjugated) steroids from the non-aqueous (non-conjugated) steroids in the organic phase. The latter is further separated by high-performance liquid chromatography (HPLC) and collected in an automated fraction collector based on the UV detection of internal standards. Commercially available immunoassays are then used to quantify the < ng/ml concentrations of steroids in each fraction. This protocol was designed for small samples of nipple aspirate fluid (minimum 2 µL), but it can be modified to fractionate steroids from homogenized solid tissue samples or other liquid biopsies. Included in this protocol are precautions to help ensure reproducibility and minimize matrix effects and other errors of measurement, given that samples requiring fractionation are fundamentally precious and, like other quantitative procedures of small samples, can be prone to contamination by solvent residues and other factors.•

The method permits quantitative analysis of multiple steroids from very small volumes of biofluid.

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Fractionation by HPLC provides a highly purified sample for quantification.

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The immunoassay end point provides specificity without expensive equipment.

Functions of dehydroepiandrosterone in relation to breast cancer

Although DHEA sulfate (DS) is the most abundant steroid in the circulation, breast fluid contains an approximately 80-fold greater concentration than serum. Transport of DS into cells requires organic anion transporting polypeptides (OATPs), which are specific for cell type, cell location, and substrate, but may have a broader specificity for housekeeping functions. Specific classes, which may be modified by soluble factors including neutral steroids, have been identified in the breast. After transport, DS may be cleaved to DHEA by ubiquitous sulfatases, which may be modified by the cell milieu, or DHEA may enter by diffusion. Synthesis from cholesterol does not occur because CYP17B12 and cytochrome b5 are lacking in breast tissues. Case-control studies reveal a positive association of serum DS with risk of breast cancer. The association is even greater with DHEA, particularly in postmenopausal women with HR + invasive tumors. Metabolites of DHEA, androstenedione and testosterone, are associated with breast cancer but DHEA is likely to have an independent role as well. Mechanisms by which DHEA may promote breast cancer relate to its effect in increasing circulating IGF-I, by inhibiting the suppressive effect of glucocorticoids, and by promoting retention of pre-adipocytes with aromatase activity. In addition, DHEA may interact with the G-protein coupled receptor GPER for stimulation of miR-21 and subsequent activation of the MAPK pathway. DHEA also has antitumor properties that relate to stimulation of immunity, suppression of inflammation, and elevation of adipose tissue adiponectin synthesis. The net effect may depend on the which factors predominate.

Association of genetic polymorphisms with local steroid metabolism in human benign breasts

PURPOSE

Although alterations of concentrations in circulating steroids have been linked to single nucleotide polymorphisms (SNPs) of steroidogenic enzymes, we hypothesized that SNPs of such enzymes located within the breast affect local steroid concentrations more than products of such SNPs absorbed from the circulation.

METHODS

Steroids (estradiol, estrone, testosterone, androstenedione, DHEA, DHEA sulfate, progesterone) in nipple aspirate fluid (NAF) were purified by HPLC and they along with serum steroids were quantified by immunoassays. Polymorphisms of the transporter SLCO2B1 and enzymes HSD3B1, CYP19A1, HSD17B12, AKR1C3, CYP1B1, and SRD5A1 were measured in white blood cell DNA.

RESULTS

Steroid concentrations in NAF of subjects with homozygous minor genotypes differed from those with heterozygotes, i.e., SLCO2B1 (rs2851069) decreased DHEAS (p = 0.04), HSD17B12 (rs11555762) increased estradiol (p < 0.004), and CYP1B1 (rs1056836) decreased estradiol (p = 0.017) and increased progesterone (p = 0.05). Also, in serum, CYP19A1 (rs10046 and rs700518) both decreased testosterone (p = 0.02) and SRD5A1 increased androstenedione (p = 0.006). Steroids in subjects with major homozygotes did not differ from those with heterozygotes indicating recessive characteristics.

CONCLUSIONS

In the breast, SNPs were associated with decreased uptake of DHEAS (SLCO2B1), increased estradiol concentrations through increased oxidoreductase activity (HSD17B12), or decreased estradiol concentrations by presumed formation of 4-hydroxyestradiol (CYP1B1). CYP19A1 was associated with decreased testosterone concentrations in serum but had no significant effect on estrogen or androgen concentrations within the breast. The hormone differences observed in NAF were not usually evident in serum, indicating the importance of assessing the effect of these SNPs within the breast.

Effects of web-based cognitive behavioral stress management and health promotion interventions on neuroendocrine and inflammatory markers in men with advanced prostate cancer: A randomized controlled trial

Cognitive behavioral stress management (CBSM) improves quality of life and mitigates stress biology in patients with early-stage cancer, including men with localized prostate cancer. However, treatments for advanced prostate cancer like androgen deprivation therapy (ADT) can lead to significant symptom burden that may be further exacerbated by stress-induced inflammation and cortisol dysregulation. The aim of this study was to examine the effects of CBSM (versus an active health promotion control) on circulating inflammatory markers and cortisol in men with advanced prostate cancer.

METHODS

Men with stage III or IV prostate cancer (N = 192) who had undergone ADT within the last year were randomized to CBSM or health promotion. Both interventions were 10 weeks, group-based, and delivered online. Venous blood was drawn at baseline, 6 months, and 12 months to measure circulating levels of CRP, IL-6, IL-8, IL-10, and TNF-α. Saliva samples were collected at awakening, 30 min after awakening, evening, and night for two consecutive days at baseline, 6-months, and 12-months to measure diurnal cortisol slopes.

RESULTS

Mixed modeling analyses demonstrated that changes in inflammatory markers and cortisol did not differ by intervention. Men in both CBSM and health promotion showed decreases in IL-10, IL-8, and TNF-α from baseline to 6 months (β = -3.85--5.04, p's = 0.004-<0.001). However, these markers generally demonstrated a rebound increase from 6 to 12 months (β = 1.91-4.06, p's = 0.06-<0.001). Men in health promotion also demonstrated a flatter diurnal cortisol slope versus men in CBSM at 6 months (β = -2.27, p = .023), but not at 12 months. There were no intervention effects on CRP, IL-6, or overall cortisol output.

CONCLUSIONS

Contrary to hypotheses, CBSM did not lead to changes in the circulating inflammatory markers and cortisol relative to health promotion. CBSM may be associated with healthy diurnal cortisol rhythm because of its focus on cognitive behavioral approaches to stress management. More research is needed to understand the impact of CBSM and health promotion on biomarkers among men with advanced prostate cancer.

Adiposity Results in Metabolic and Inflammation Differences in Premenopausal and Postmenopausal Women Consistent with the Difference in Breast Cancer Risk

Obesity is associated with increased risk of breast cancer in postmenopausal but not in premenopausal women. Many factors may be responsible for this difference. The aim of this study was to determine the mechanisms by which the genes related to the AMPK pathway, inflammation, and estrogen actions are affected by adiposity in breast tissue with the objective of identifying differences that may explain the different breast cancer risk in premenopausal and postmenopausal women. Random fine needle aspirates (rFNAs) of breast tissue were collected from 57 premenopausal and 55 postmenopausal women and were classified as normal weight, overweight, or obese. Expression levels of 21 target genes were determined using a TaqMan Low Density Array procedure. Breast tissue estradiol levels were measured by a liquid chromatography-tandem mass spectrometry procedure, and serum estradiol and follicle-stimulating hormone (FSH) were measured by a radioimmunoassay and an enzyme-linked immunosorbent assay, respectively. We found that in postmenopausal women, serum and tissue estradiol levels were increased in those who were overweight, and serum FSH levels were decreased in obese status. Interestingly, RPS6KB1, an AMPK downstream-responsive gene for protein synthesis and cell growth, and estrogen receptor α (encoded by the ESR1 gene) and its target gene GATA3 were significantly decreased in rFNA of premenopausal, obese women. In postmenopausal women, RPS6KB1, ESR1, and GATA3 expression remained unchanged in relation to adiposity. However, prostaglandin-endoperoxide synthase 2 (PTGS2), cyclin D1 (CCND1), and another ESR1 target gene, TFF1, were elevated in rFNA of obese postmenopausal women. Thus, as bodyweight increases, gene expression is indicative of increased proliferation in postmenopausal women but decreased proliferation in premenopausal women. Overall, our data reveal a novel process by which obesity promotes the risk of breast cancer in postmenopausal but not premenopausal women.

Author Correction: Childhood ecology influences salivary testosterone, pubertal age and stature of Bangladeshi UK migrant men

In the version of this Article originally published, the units for the 'Weight' column in Table 1 were incorrect; they should have been kg. This has now been corrected.

Breast Hormone Concentrations in Random Fine-Needle Aspirates of Healthy Women Associate with Cytological Atypia and Gene Methylation

Sex steroid hormones contribute to breast cancer development, but data on concentrations of these within breast tissue are limited. We performed simultaneous multiparameter measurement of breast sex steroids, breast epithelial cytology, and DNA methylation in 119 healthy women (54 pre- and 65 postmenopausal) without a history of breast cancer. Random fine-needle aspiration (rFNA) of the breast was performed simultaneously with blood collection. Breast samples were analyzed by LC/MS-MS for estrone, estradiol, progesterone, androstenedione, and testosterone. Blood samples were assayed for estradiol and progesterone by immunoassay. Cytomorphology was classified using the Masood Score, and DNA methylation of eight genes was analyzed using quantitative multiplexed methylation-specific PCR, and expressed as the cumulative methylation index (CMI). Serum and breast concentrations of estradiol and progesterone showed significant correlation (Spearman r = 0.34, P_adj = 0.001 and r = 0.69, P_adj < 0.0006, respectively). Progesterone concentration was significantly higher in the premenopausal breast (P_adj < 0.0008), and showed a luteal surge. Breast estrone and estradiol concentrations did not differ significantly by menopause, but androstenedione concentration was higher in the breasts of postmenopausal women (P = 0.026 and P_adj = 0.208). Breast androgens were significantly correlated with breast density (Spearman r = 0.27, P_adj = 0.02 for testosterone) and CMI (Spearman r = 0.3, P_adj = 0.038 for androstenedione). Our data indicate that future larger studies of breast steroid hormones along with other parameters are feasible. Significant associations of breast androgen concentrations with breast density and gene methylation warrant future study. Cancer Prev Res; 11(9); 557-68. ©2018 AACR.

Abstract A22: Association of breast cancer risk and concentrations of tissue estrogens to single strand breaks in DNA

Introduction: Single-strand breaks (SSB) in DNA are discontinuities in one strand of the DNA and are usually accompanied by loss of a single base and by damaged 5- or 3-termini at the site of the break. If not repaired rapidly or appropriately, chromosomal SSBs pose a serious threat to genetic stability and cancer development. We hypothesize that if the presence of single strand DNA breaks can be quantified directly, it will provide a means of detecting a process that puts cells at high risk of developing cancer. The association between a quantitative measure of SSB and other measures of breast cancer risk was determined.

Subjects: 206 postmenopausal and 99 premenopausal, healthy women with intact, healthy bilateral breasts, without implants or history of radiation, willing to undergo a random fine-needle aspiration (rFNA) of the breast within 3.5 months of a normal mammogram were recruited to the study. Exclusions: use of tamoxifen, raloxifene, or aromatase inhibitor within 2 years of participation or oral contraceptives or other hormone treatments within 3 months of study enrollment. Participants completed personal and medical history questionnaires. Blood for hormone levels and random fine needle aspirates of the breast (rFNA) were collected following a breast exam.

Methods: rFNA of the breast of women at unspecified risks for breast cancer were analyzed for SSB by a nick translation procedure. SSB levels digital two-dimensional breast density of the entire breast (PBD), mRNA of genes associated with DNA damage, and breast steroid concentrations by a LC/MS/MS procedure.

Results: Based on the cpm in the purified sample, the specific activity of the 3H-dCTP, and quantity of DNA in the sample, the incorporation of 3H-dCTP ranged from 0.03 to 8.59 pmol/µg DNA. The β-coefficients for the relationships between SSB and measures of breast cancer risk were determined by a multiple regression procedure. PBD adjusted for age was associated with SSB in postmenopausal women (P = 0.007) but was not associated with SSB in premenopausal women. Further adjustment for BMI reduced the PBD relationship to SSB by 35% but adjustment for BMI. APEX1 was not significantly associated with SSB. XRCC1 mRNA was negatively associated with SSB in premenopausal women (p = 0.016), and was not altered by adjustment for age. The antioxidant functions NRF-1 and SOD2 were both significantly negatively associated with SSBs, P = 0.001 and 0.045, respectively, and both were decreased by less than 5% after adjustment for age. Breast tissue concentrations of 4-hydroxyestradiol exceeded those of estradiol, were correlated with tissue estradiol, and were significantly (P = 0.011) negatively related to SSB levels. Breast tissue concentrations of estradiol, estrone, 4-hydroxyestrone, and androstenedione were not significantly related to SSB.

Conclusions: The most likely mechanism by which 4-OHE2 or 2-OHE1 could protect against formation of SSBs in the breast is by their antioxidative properties. 4-OHE2 and other catechol estrogens are capable of undergoing redox reactions, cycling between the catechol structure, semiquinone radical, and o-quinone. They are also capable of forming metal complexes, sequestering metals, preventing them from undergoing redox reactions. In addition, 4-OHE2 has a binding affinity relative to that of estradiol of 1.51; that of 2-OHE1 is 1.02 Therefore, the catechol estrogens have activity similar to or greater than that of estradiol in terms of activation of NRF-1 and Mn SOD, both of which were elevated in association with lower SSB levels. We conclude that SSBs measured by the nick translation procedure are associated with, but not redundant with, measures of breast cancer risk and with deficiencies of both DNA damage responses and antioxidant mechanisms. Concentrations of 4-hydroxyestradiol in breast tissue may serve an antioxidant function and may be protective.

Citation Format: Mathavi Sahadevan, Oukseub Lee, Miguel Muzzio, Belinda Phan, Lisa Jacobs, Nagi Khouri, Jun Wang, Hong Hu, Vered Stearns, Robert T. Chatterton. Association of breast cancer risk and concentrations of tissue estrogens to single strand breaks in DNA. [abstract]. In: Proceedings of the AACR Special Conference: Improving Cancer Risk Prediction for Prevention and Early Detection; Nov 16-19, 2016; Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(5 Suppl):Abstract nr A22.

The relationship of single-strand breaks in DNA to breast cancer risk and to tissue concentrations of oestrogens

CONTEXT

Clinical study of breast cancer patients in Chicago, IL, USA.

OBJECTIVE

Ascertain the utility of measurements of single-strand breaks (SSB) in DNA for assessment of breast cancer risk.

METHODS

Fine-needle aspirates of the breast, SSB by nick translation, percent breast density (PBD), Gail model risk, cumulative methylation index (CMI), enzymes of DNA repair and tissue antioxidants.

RESULTS

DNA repair enzymes and 4-hydroxyestradiol were negatively associated with SSB; CMI and PBD were positively associated.

CONCLUSIONS

Quantitative measurement of SSBs by this procedure indicates the relative number of SSBs and is related to promoter methylation, antioxidant availability and percent breast density.

AMP-activated protein kinase and energy balance in breast cancer

Cancer growth and metastasis depends on the availability of energy. Energy-sensing systems are critical in maintaining a balance between the energy supply and utilization of energy for tumor growth. A central regulator in this process is AMP-activated protein kinase (AMPK). In times of energy deficit, AMPK is allosterically modified by the binding of increased levels of AMP and ADP, making it a target of specific AMPK kinases (AMPKKs). AMPK signaling prompts cells to produce energy at the expense of growth and motility, opposing the actions of insulin and growth factors. Increasing AMPK activity may thus prevent the proliferation and metastasis of tumor cells. Activated AMPK also suppresses aromatase, which lowers estrogen formation and prevents breast cancer growth. Biguanides can be used to activate AMPK, but AMPK activity is modified by many different interacting factors; understanding these factors is important in order to control the abnormal growth processes that lead to breast cancer neoplasia. Fatty acids, estrogens, androgens, adipokines, and another energy sensor, sirtuin-1, alter the phosphorylation and activation of AMPK. Isoforms of AMPK differ among tissues and may serve specific functions. Targeting AMPK regulatory processes at points other than the upstream AMPKKs may provide additional approaches for prevention of breast cancer neoplasia, growth, and metastasis.

Neuroendocrine Responses to Stressors in Lactating and Nonlactating Mammals: A Literature Review

Although stress research is a popular topic of study, little is known about the neuroendocrine responses to a stressor in lactating and nonlactating humans. The purpose of this systematic review of the literature was to examine the neuroendocrine responses, specifically the glucocorticoids and catecholamines, in lactating and nonlactating animals and humans to an acute stressor. A brief overview of the physiological stress response in the human is included. Animal studies strongly suggest that lactation is associated with major changes in neuroendocrine responses to a variety of acute stressors. Neuroendocrine responses in humans to stressors are less clear due to the limited research. Future research is needed involving these responses in humans generally, as well as specifically in the patterns of neuroendocrine responses to chronic stressors in lactating and nonlactating women.

Psychological Distress and Milk Volume in Lactating Mothers

The purpose of this article is twofold: (a) to compare psychological distress as measured via self-reported perceived stress, sleep, and fatigue levels in lactating mothers of a term infant and mothers of a preterm infant and(b) to determine whether the addition of psychological distress to a previous model predicts milk volume at Postpartum Week 6 by gestation group. The convenience sample of 95 mothers of a preterm infant (31 weeks) and 98 mothers of a term infant completed the Perceived Stress Visual Analogue Scale, Richards-Campbell Sleep Questionnaire, and the Fatigue Visual Analog Scale. Stress, sleep difficulty, and fatigue levels decreased during the 6-week study period for mothers of a term but not for mothers of a preterm infant. Perceived stress, sleep difficulty, and fatigue during the first 6 weeks postpartum were not related to milk volume; thus, the mother’s perceived psychological distress had no apparent effect on lactation.

Gene Methylation and Cytological Atypia in Random Fine-Needle Aspirates for Assessment of Breast Cancer Risk

Methods to determine individualized breast cancer risk lack sufficient sensitivity to select women most likely to benefit from preventive strategies. Alterations in DNA methylation occur early in breast cancer. We hypothesized that cancer-specific methylation markers could enhance breast cancer risk assessment. We evaluated 380 women without a history of breast cancer. We determined their menopausal status or menstrual cycle phase, risk of developing breast cancer (Gail model), and breast density and obtained random fine-needle aspiration (rFNA) samples for assessment of cytopathology and cumulative methylation index (CMI). Eight methylated gene markers were identified through whole-genome methylation analysis and included novel and previously established breast cancer detection genes. We performed correlative and multivariate linear regression analyses to evaluate DNA methylation of a gene panel as a function of clinical factors associated with breast cancer risk. CMI and individual gene methylation were independent of age, menopausal status or menstrual phase, lifetime Gail risk score, and breast density. CMI and individual gene methylation for the eight genes increased significantly (P < 0.001) with increasing cytological atypia. The findings were verified with multivariate analyses correcting for age, log (Gail), log (percent density), rFNA cell number, and body mass index. Our results demonstrate a significant association between cytological atypia and high CMI, which does not vary with menstrual phase or menopause and is independent of Gail risk and mammographic density. Thus, CMI is an excellent candidate breast cancer risk biomarker, warranting larger prospective studies to establish its utility for cancer risk assessment. Cancer Prev Res; 9(8); 673-82. ©2016 AACR.

Genetic Determinants of Nipple Aspiration Fluid Yield

PURPOSE

Nipple aspiration fluid (NAF) is a non-invasively-acquired biosample that can provide a window into the breast environment, but NAF yield is highly variable. Its determinants must be better understood for studies of breast cancer risk. The wet earwax phenotype was identified as one determinant of NAF yield in the 1970s, and is linked to single nucleotide polymorphisms (SNPs) in the ATP-binding cassette transporter gene ABCC11. We have investigated this, as well as SNPs in the prolactin (PRL) and prolactin receptor (PRLR) genes, in relation to NAF yield.

METHODS

DNA was extracted from white blood cells of 557 NAF yielders and 359 non-yielders, and was used to genotype ABCC11 (rs17822931), PRL (rs849870, rs849872, rs849886, rs2244502, rs1341239), and PRLR (rs37364, rs34024951, rs1610218, rs9292575, rs7718468) using Taqman genotyping assay. The association between NAF yield and each single SNP was analyzed using logistic regression adjusting for age, race, and menopausal status.

RESULTS

ABCC11 rs17822931 showed a negative association with NAF yield [odds ratio (OR) 0.66, 95 % confidence interval (CI) 0.49-0.88; p = 0.004]. The PRL rs849870 and the haplotype combination with other SNPs showed a marginal association with NAF yield. In addition, the years since last birth also showed negative association with NAF yielding (OR 0.98, 95 % CI 0.96-0.99; p = 0.001). The combination of the years since last birth with ABCC11 SNP revealed significant interaction between reproductive factor and genetic factor.

CONCLUSIONS

Our results confirmed the association between NAF yield and earwax phenotype through ABCC11 genotype. Combined with the recency of last birth, ABCC11 genotype should be considered in the design of studies utilizing NAF as a biosample.

Nipple Aspirate Fluid Hormone Concentrations and Breast Cancer Risk

Prior reports identify higher serum concentrations of estrogens and androgens as risk factors for breast cancer, but steroids in nipple aspirate fluid (NAF) may be more related to risk. Incident breast cancer cases and mammography controls were recruited. Sex steroids were measured in NAF from the unaffected breasts of cases and one breast of controls. Menopausal status and menstrual cycle phase were determined. NAF steroids were purified by HPLC and quantified by immunoassays. Conditional logistic regression models were used to examine associations between NAF hormones and case-control status. NAF samples from 160 cases and 157 controls were evaluable for hormones. Except for progesterone and dehydroepiandrosterone (DHEA), the NAF and serum concentrations were not significantly correlated. NAF estradiol and estrone were not different between cases and controls. Higher NAF (but not serum) DHEA concentrations were associated with cases, particularly among estrogen receptor (ER)-positive cases (NAF odds ratio (OR) = 1.18, 95 % confidence interval (CI) 1.02, 1.36). NAF DHEA was highly correlated with NAF estradiol and estrone but not with androstenedione or testosterone. Higher progesterone concentrations in both NAF and serum were associated with a lower risk of ER-negative cancer (NAF OR = 0.69, 95 % CI 0.51, 0.92). However, this finding may be explained by case-control imbalance in the number of luteal phase subjects (2 cases and 19 controls). The significantly higher concentration of DHEA in NAF of cases and its correlation with NAF estradiol indicates a potentially important role of this steroid in breast cancer risk; however, the negative association of progesterone with risk is tentative.

A randomized phase II presurgical trial of transdermal 4-hydroxytamoxifen gel versus oral tamoxifen in women with ductal carcinoma in situ of the breast

PURPOSE

Local transdermal therapy to the breast may achieve effective target-organ drug delivery, while diminishing systemic effects. We conducted a randomized, double-blind, placebo-controlled phase II trial comparing transdermal 4-hydroxytamoxifen gel (4-OHT) to oral tamoxifen (oral-T) in women with ductal carcinoma in situ (DCIS).

METHODS

Twenty-seven pre- and postmenopausal women were randomized to 4-OHT (4 mg/day) or oral-T (20 mg/day) for 6 to 10 weeks before surgery. Plasma, nipple aspirate fluid, and breast adipose tissue concentrations of tamoxifen and its major metabolites were determined by liquid chromatography/tandem mass spectrometry. The primary endpoint was Ki67 labeling in DCIS lesions, measured by immunohistochemistry. In plasma, insulin-like growth factor-1 (IGFI), sex hormone-binding globulin (SHBG), and coagulation protein concentrations were determined.

RESULTS

Posttherapy Ki67 decreased by 3.4% in the 4-OHT and 5.1% in the oral-T group (P ≤ 0.03 in both, between-group P = 0. 99). Mean plasma 4-OHT was 0.2 and 1.1 ng/mL in 4-OHT and oral groups, respectively (P = 0.0003), whereas mean breast adipose tissue concentrations of 4-OHT were 5.8 ng/g in the 4-OHT group and 5.4 ng/g in the oral group (P = 0.88). There were significant increases in plasma SHBG, factor VIII, and von Willebrand factor and a significant decrease in plasma IGFI with oral-T, but not with 4-OHT. The incidence of hot flashes was similar in both groups.

CONCLUSIONS

The antiproliferative effect of 4-OHT gel applied to breast skin was similar to that of oral-T, but effects on endocrine and coagulation parameters were reduced. These findings support the further evaluation of local transdermal therapy for DCIS and breast cancer prevention.

Methodological considerations in estrogen assays of breast fluid and breast tissue

Estradiol (E2) in nipple aspirate fluid (NAF), ductal lavage fluid (DLF), and random fine needle aspirates (rFNA) are compared. Quantification was by immunoassay or tandem MS. The percent of women yielding NAF varied between 24% and 48% and for DLF was 86.3%. Variation between ducts within a breast was not less than variation between breasts within women but variation between breasts and within women over time was significantly less than variation between women. Serum E2 was highly significantly different among phases of the menstrual cycle but NAF E2 was not different. The correlation between serum and breast fluid E2 concentrations in premenopausal women had coefficients of determination of less than 15%. The correlation between serum and NAF in studies of postmenopausal women varied greatly and may depend on patient selection. The difference between NAF E2 between pre- and postmenopausal women was only 22%; for rFNA it was non-significantly 44% lower in a similar group of postmenopausal women. Progesterone was 96% and 98% lower in postmenopausal NAF and rFNA samples, respectively. Measurements of E2 in breast fluid or breast tissue appears to provide similar estimates of E2 exposure. E2 levels in breast fluid do not reflect the rapid changes that occur in serum and, thus, serum availability of E2 is only one factor determining its levels in the breast. The similarity of levels between breasts and between ducts suggests that estimates of estrogen exposure does not require multiple samples, however, unavailability of fluid may require rFNA in some cases.

Comment on "Progesterone/RANKL is a major regulatory axis in the human breast"

In vivo menstrual cycle data support the findings by Tanos et al. that progesterone regulates RANKL in an ex vivo microstructure model of the human breast, but dispute the suppression of estradiol on progesterone-stimulated RANKL expression. RANKL responds to progesterone in a three-dimensional organoid culture model under conditions mimicking luteal-phase hormone concentration, suggesting that the microstructure may not be crucial to demonstrate progesterone responsiveness.

RANKL expression in normal and malignant breast tissue responds to progesterone and is up-regulated during the luteal phase

The receptor activator of nuclear factor-κB ligand (RANKL) acts as a paracrine factor in progesterone-induced mammary epithelial proliferation and tumorigenesis. This evidence comes mainly from mouse models. Our aim was to examine whether RANKL expression in human normal and malignant breast is under the control of progesterone throughout the menstrual cycle. Breast epithelial samples were obtained by random fine needle aspiration (rFNA) of the contralateral unaffected breasts (CUB) of 18 breast cancer patients, with simultaneous serum hormone measurements. Genes correlated with serum progesterone levels were identified through Illumina microarray analysis. Validation was performed using qRT-PCR in rFNA samples from CUB of an additional 53 women and using immunohistochemistry in tissue microarrays of 61 breast cancer samples. Expression of RANKL, DIO2, and MYBPC1 was correlated with serum progesterone in CUB, and was significantly higher in luteal phase. RANKL and MYBPC1 mRNA expression were highly correlated between CUB and matched tumor samples. RANKL protein expression was also significantly increased in the luteal phase and highly correlated with serum progesterone levels in cancer samples, especially in hormone receptor positive tumors. The regulatory effects of progesterone on the expression of RANKL, DIO2, and MYBPC1 were confirmed in three-dimensional cultures of normal breast organoids. In normal breast and in breast cancer, RANKL mRNA and protein expression fluctuate with serum progesterone with highest levels in the luteal phase, suggesting that RANKL is a modulator of progesterone signaling in normal and malignant breast tissue and a potential biomarker of progesterone action and blockade.

Hormonal determinants of nipple aspirate fluid yield among breast cancer cases and screening controls

BACKGROUND

Nipple aspiration fluid (NAF) use as a biosample is limited by the variable yield across studies. We investigated the endocrine determinants of yield in an ongoing breast cancer case-control study.

METHODS

One-hundred and eighteen women yielding ≥2 μL NAF and 120 non-yielders were included; serum hormones were measured; differences in median hormones were assessed using the Wilcoxon rank-sum test. ORs and 95% confidence intervals (95% CI) for yielder status relative to hormone levels were estimated using logistic regression, adjusting for parity and lactation, and, in premenopausal women, menstrual cycle phase (MCP).

RESULTS

Prolactin concentrations were higher in yielders than non-yielders (premenopausal: 7.6 and 2.5 ng/mL, P < 0.01; postmenopausal 5.3 and 2.2 ng/mL; P < 0.01). Among premenopausal-yielders, estradiol was lower (64.3 vs. 90.5 pg/mL, MCP-adjusted P = 0.02). In separate menopausal status and parity-adjusted models, significant case-control differences persisted in prolactin: case OR 1.93 (95% CI, 1.35-2.77), control OR 1.64 (95% CI, 1.17-2.29). Premenopausal control yielders had higher progesterone (OR, 1.70; 95% CI, 1.18-2.46) and sex-hormone binding-globulin (OR, 2.09; 95% CI, 1.08-4.05) than non-yielders. Among parous women, further adjustment for lactation suggested a stronger positive association of serum prolactin with yield in cases than controls.

CONCLUSION

NAF-yielders show higher prolactin than non-yielders, regardless of menopause and parity; implications of this and other endocrine differences on NAF biomarkers of breast cancer risk deserve further study.

IMPACT

NAF yield is associated with a distinct endocrine environment that must be considered in studies of NAF-based breast cancer risk markers.

Abstract 90: Estrogen accelerates the development of estrogen receptor-negative breast cancer

Long-term cumulative exposure to estrogen increases the breast cancer risk in women. Breast tissue must have a normal complement of estrogen receptor (ER) and progesterone receptor (PGR) for the normal development of breast tissue. Clinically, about 22% of patients with breast cancer overexpress the ERBB2 (HER2/neu) receptor tyrosine kinase. However, many HER2/neu-positive mammary tumors do not express ER or PGR by the time they are clinically recognizable. So far, the role of estrogen in the development of ER-negative breast cancers is not clearly defined. Aromatase is a key enzyme for estrogen biosynthesis and its expression pattern between human and mouse is drastically different. We generated transgenic humanized aromatase (Aromhum) mice to mimic the human aromatase distribution pattern in the mouse. Aromhum mice exhibited an increased incidence of lobuloalveolar breast hyperplasia associated with increased estrogen levels locally in mammary glands but not in the circulation. To demonstrate the important role of ER signaling in ER-negative breast tumor development and eventually to test a prevention strategy using aromatase inhibitors in this mouse model, Aromhum mice were crossed with ERBB2 transgenic mice to generate wild-type (WT), Aromhum, ERBB2 and Aromhum/ERBB2 (AE) mice. WT or Aromhum transgenic mice were free of tumors during the 26 week of follow-up. On the other hand, 56% of ERBB2 (only) mice developed mammary tumors, as expected. Interestingly, AE mice had a significantly higher (86%, p&lt;0.05) tumor incidence compared with ERBB2 mice. Thus, it appeared that the human aromatase transgene increased the rate of ERBB2–induced mammary tumor growth. The tumors that arose in either ERBB2 or AE mice were histological adenocarcinomas as was previously reported for the ERBB2 transgenic mice. Levels of ER and PGR in benign mammary epithelial cells were higher in Aromhum and AE mice as compared to WT and ERBB2 mice. We further measured the dynamic change of sex hormone receptor status from normal mammary epithelial cells to fully developed tumors. Different stages of mammary tumors were chosen from nonpalpable microscopic visible early stage tumor to various sizes of late stage tumors. ER and PGR were present in early stage tumor but gradually decreased and eventually were absent in late stage tumors. The estrogen response gene, cyclin D1 was higher in benign and malignant mammary epithelium of Aromhum and AE mice compared with WT mice. Cell proliferation evaluated by Ki67 staining was significantly higher in benign mammary epithelium and tumors of AE mice as compared to those of ERBB2 mice. In conclusion, estrogen expedited the early development of ER-negative mammary tumors caused by a primary genetic hit (HER2/neu) via increasing cell proliferation through ER-mediated signal transduction. This study provides a fundamental mechanism for testing prevention strategies using aromatase inhibitors in this mouse model.

Citation Format: Hong Zhao, John S. Coon, Robert T. Chatterton, Dolores Huberts, David Christopher Brooks, Francesco J. DeMayo, Serdar E. Bulun. Estrogen accelerates the development of estrogen receptor-negative breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 90. doi:10.1158/1538-7445.AM2013-90

Lipid metabolism genes in contralateral unaffected breast and estrogen receptor status of breast cancer

Risk biomarkers that are specific to estrogen receptor (ER) subtypes of breast cancer would aid the development and implementation of distinct prevention strategies. The contralateral unaffected breast of women with unilateral breast cancer (cases) is a good model for defining subtype-specific risk because women with ER-negative (ER-) index primaries are at high risk for subsequent ER-negative primary cancers. We conducted random fine needle aspiration of the unaffected breasts of cases. Samples from 30 subjects [15 ER-positive (ER+) and 15 ER- cases matched for age, race and menopausal status] were used for Illumina expression array analysis. Findings were confirmed using quantitative real-time PCR (qRT-PCR) in the same samples. A validation set consisting of 36 subjects (12 ER+, 12 ER- and 12 standard-risk healthy controls) was used to compare gene expression across groups. ER- case samples displayed significantly higher expression of 18 genes/transcripts, 8 of which were associated with lipid metabolism on gene ontology analysis (GO: 0006629). This pattern was confirmed by qRT-PCR in the same samples, and in the 24 cases of the validation set. When compared to the healthy controls in the validation set, significant overexpression of 4 genes (DHRS2, HMGCS2, HPGD and ACSL3) was observed in ER- cases, with significantly lower expression of UGT2B11 and APOD in ER+ cases, and decreased expression of UGT2B7 in both subtypes. These data suggest that differential expression of lipid metabolism genes may be involved in the risk for subtypes of breast cancer, and are potential biomarkers of ER-specific breast cancer risk.

Abstract P1-09-07: Topical 4-OHT trial in women with DCIS of the breast: report of plasma and breast tissue concentration of tamoxifen metabolites

Background: Earlier studies have shown that 1–2mg of 4-hydroxytamoxifen (4–OHT) gel applied to the breast skin reduced cell proliferation in estrogen receptor (ER) positive invasive cancers to a similar degree as oral tamoxifen (TAM), with significantly lower plasma levels. We now report results of a Phase IIB pre-surgical window trial of women with DCIS, designed to obtain pilot data in early lesions. Our ultimate goal is to develop transdermal 4-OHT as an alternative to oral TAM for women at high risk for breast cancer and those with DCIS. The study was closed early because the manufacturer discontinued the drug supply, but remains blinded until all biomarker analysis is complete. Here we report the plasma and breast adipose tissue concentration of TAM metabolites from the topical 4-OHT gel group (4 mg) in comparison with the oral TAM group (20mg).

Methods: Women with DCIS were enrolled, and randomized to 4-OHT gel (4mg/day, 2mg per breast, E: Z isomers = 1:1,) or to oral (Z) TAM (20mg/day) for 4–10 weeks before surgery. Blood was collected on the day of surgery, and breast adipose tissue was collected at surgery. There were a total of 22 patients with matched blood and breast adipose tissue. The concentration of TAM metabolites in plasma and breast tissue was determined with liquid chromatography/tandem mass spectrometry. We assumed that the subjects with detectable N-desmethyl TAM (NDT) in plasma belong to the oral TAM group because NDT is not a product of 4-OHT metabolism. Under this assumption, 13 subjects were categorized into oral TAM group, and 9 subjects into the topical 4-OHT group. Wilcoxon rank-sum test was used for statistical analysis.

Results: The results are shown in the table. The concentration is presented as mean ± SD; the lowest quantitation limit (LQL) was 1 ng/mL for plasma, and 3 ng/g for tissue. TAM and its metabolites were found in the plasma of the presumed oral TAM group, with high levels of TAM and NDT. In the presumed 4-OHT gel group, only (Z) 4-OHT was found in the plasma although both (E) and (Z) forms were applied. The mean plasma level of 4-OHT in the gel group was 70% lower than the mean of 4-OHT in the oral TAM group (p = 0.004). In breast tissue, similar amounts of (E) and (Z) forms of 4-OHT were found in the 4-OHT gel group, with the (Z) 4-OHT level being equivalent to that in the oral TAM group (p = 0.48). Endoxifen was only found in the oral TAM group. We saw no evidence of further metabolic transformation of 4-OHT in the breast following topical administration.

Abstract P4-12-04: Association of single-strand breaks (SSBs) in normal breast DNA with estimates of breast cancer risk

Background: Formation of single strand breaks in DNA is a constant process, estimated to occur 10,000 times per day in each cell, either from endogenous biosynthetic errors or from interference by endogenous or exogenous agents. Base excision repair in some cases may be impaired or may be exceeded by the rate of DNA damage, leading to cancer. Nick translation of with labeled nucleotides can be used as a quantitative indicator of SSBs.

Methods: Healthy women were recruited through the Love-Avon Army of Women and breast clinics of Northwestern and John Hopkins Universities. Digital or digitized mammograms were evaluated for percent density using Cumulus software. The medians (ranges) were age 51 (36 to 60); BMI 28.2 (18.7 to 51.3); life-time Gail estimate 12.5 (5.6 to 28.3); % breast density 16.5 (2.4 to 52.5); Masood score 13 (0 to 18). Breast tissue was obtained by random fine needle aspiration (rFNA). Specimens were rinsed into ice-cold phosphate buffered saline and were stored at −80°C. Thawed samples were centrifuged at 2200 g for 60 min. A kit from Norgen Inc., was used to separate DNA, RNA, and protein from the pellet. The lipids were extracted with ethyl acetate-hexane (3:2) from the supernatant fluid, and triglycerides were precipitated from cold 90% methanol, leaving a purified lipid fraction containing the steroids. Steroids were then fractionated by HPLC on a C18 column, and estradiol was analyzed by a radioimmunoassay. Blood was obtained at the same time as the rFNA samples and was frozen prior to analysis. An aliquot containing 200 ng of DNA (260/280 ratio 1.3 to 2.3) was taken for the nick translation assay. Incorporation of free nucleotides at SSBs with dCTP labeled with3H was catalyzed by Polymerase I from E. coli. A quality control preparation prepared from calf thymus DNA and a reagent blank without DNA was included with each set of 6 samples. Incorporation of3H-dCTP was linear with dose of DNA and reached a maximal at 30 min. Separation of free from incorporated3H-dCTP was accomplished by gel chromatography on an 80 × 15 mm column. The concordance of interassay values was 0.96.

Abstract P3-04-08: Expression of hormone-responsive genes in benign breast tissue varies with menstrual cycle phase and menopausal status

Background: The expression of many genes is known to be regulated by ambient hormone levels. In a preliminary study of random fine-needle aspirate (rFNA) samples from benign breast tissue, we found several genes that were highly correlated with the serum levels of progesterone (P4) and estradiol (E2). We now present data to further validate these genes as markers of menstrual cycle phase (MCP) and menopausal status (MPS) in benign breast tissue which may allow retrospective classification of archived breast samples with respect to MCP and MPS at the time of sampling.

Methods: 240 rFNA samples from healthy women with recorded hormonal data at the time of sampling were analyzed. We divided these subjects by menstrual cycle phase (MCP) and menopausal status (MPS): 41 early follicular: (low circulating E2 and P4); 48 mid-cycle (high E2 and low P4); 31 luteal (moderate E2 and high P4). 120 post-menopausal (low E2 and low P4). 100 ng of RNA from rFNA samples of the breast was reverse transcribed. Amplicons of interest were linearly amplified to 14 cycles for 35 genes related to hormone responsiveness. qPCR reactions were carried out using the TaqMan OpenArray (Applied Biosystems). For each gene of interest, expression levels were normalized to the average expression of GAPDH. Gene expression difference between groups were conducted using the Mann-Whitney Test. P-values from gene expression difference were adjusted via the Benjamini-Hochberg (1995) approach.

Results: The mean value of TNFSF11 expression level was 13.19 fold higher in luteal phase subjects than in post-menopausal subjects (p = 0.0003) where there was also the biggest difference of serum P4 level between groups. The expression of DIO2 and MYBPC1 was also significantly higher in luteal phase group than in the post-menopausal group (p = 0.005, p = 0.02, respectively). These 3 genes also demonstrated a higher expression pattern in luteal phase than mid-cycle and follicular phase but analysis is still ongoing. All comparisons between these groups will be presented at the meeting.

Conclusion: The expression levels of TNFSF11, DIO2 and MYBPC1 vary with MCP and MPS. These hormone-responsive genes are candidate MCP classifiers which could be applied to archived breast samples to assess whether biomarkers of breast cancer risk are stable across the menstrual cycle, since MCP and MPS variation is likely an important source of biological noise in studies of archived breast biopsy material.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-04-08.

A humanized pattern of aromatase expression is associated with mammary hyperplasia in mice

Aromatase is essential for estrogen production and is the target of aromatase inhibitors, the most effective endocrine treatment for postmenopausal breast cancer. Peripheral tissues in women, including the breast, express aromatase via alternative promoters. Female mice lack the promoters that drive aromatase expression in peripheral tissues; thus, we generated a transgenic humanized aromatase (Arom(hum)) mouse line containing a single copy of the human aromatase gene to study the link between aromatase expression in mammary adipose tissue and breast pathology. Arom(hum) mice expressed human aromatase, driven by the proximal human promoters II and I.3 and the distal promoter I.4, in breast adipose fibroblasts and myoepithelial cells. Estrogen levels in the breast tissue of Arom(hum) mice were higher than in wild-type mice, whereas circulating levels were similar. Arom(hum) mice exhibited accelerated mammary duct elongation at puberty and an increased incidence of lobuloalveolar breast hyperplasia associated with increased signal transducer and activator of transcription-5 phosphorylation at 24 and 64 wk. Hyperplastic epithelial cells showed remarkably increased proliferative activity. Thus, we demonstrated that the human aromatase gene can be expressed via its native promoters in a wide variety of mouse tissues and in a distribution pattern nearly identical to that of humans. Locally increased tissue levels, but not circulating levels, of estrogen appeared to exert hyperplastic effects on the mammary gland. This novel mouse model will be valuable for developing tissue-specific aromatase inhibition strategies.

Gene methylation in random FNA samples as biomarkers for breast cancer

518

Background: Current methods to determine breast cancer risk are insufficiently sensitive to select women most likely to benefit from preventive strategies. We hypothesized that candidate gene promoter hypermethylation may provide an individualized risk profile. We performed a prospective study to determine whether DNA cumulative methylation index (CMI) varies by menstrual phase or menopausal status, and to correlate CMI with established risk factors. Methods: We obtained random fine needle aspiration (rFNA) samples from healthy women age 35-60 and determined their menopausal and menstrual status, lifetime Gail risk, mammographic breast density, and cytologic atypia assessed as the Masood score. We evaluated CMI of 11 candidate genes in rFNA cells using the Quantitative Multiplex Methylation-Specific PCR (QM-MSP) technique. We used Wilcoxon test and ANOVA model to compare CMI across menopausal and menstrual (follicular, mid-cycle, luteal) categories, respectively. We used linear regression model to adjust for age and BMI. Methylation scores were log-transformed in the analysis. Results: We enrolled 390 women at the Avon Breast Centers at Johns Hopkins and Northwestern, the majority through the Love/Avon Army of Women, and 380 completed study procedures. Median age 50 (36-60), mean BMI 28 (18.7-50.8), 52% were postmenopausal. Mean life-time Gail risk 14.6 (5.6-54.1), mean percent mammographic density 19.6 (2.5-72.8), and mean Masood score (N=354) 13.6 (7-18). QM-MSP analysis was completed on 229 samples. We did not observe differences in CMI among menopausal (P=0.4895) or menstrual categories (P=0.2333). There was no association between CMI and life-time Gail risk (P=0.706) or breast density (P=0.4116). We observed a significant correlation between CMI and Masood score (P=0.0167). Conclusions: CMI correlates with degree of cytologic atypia and is potentially a robust indicator of breast cancer risk since it does not vary with menstrual or menopausal status. Next, we will select genes that best reflect changes in the clinical parameters to create a gene methylation signature that will be validated in other studies and correlated with breast cancer risk.

Abstract 4466: Local regulation of steroid hormones in the breast is related to single nucleotide polymorphism of steroid metabolism genes

Background: The pattern of steroid hormone levels in nipple aspirate fluid (NAF) significantly differs from systemic levels, but may be a better predictor of breast cancer risk than the systemic environment. We hypothesize that local production and clearance of estrogen precursors or estrogen in the breast is affected by genetic variation in the enzymes involved in steroid transport, biosynthesis, and metabolism, thereby contributing to breast cancer risk. We examined the effect of functional single nucleotide polymorphism (SNP) on the concentrations of the NAF steroid hormones, as compared to serum levels. Methods: NAF was collected from both the contralateral unaffected breast of breast cancer patients and controls (blinded study of 265 women). Selection criteria for SNPs were; 1) known/potential functional significance on activity of the resulting enzyme. 2) Expression in breast tissue. 3) Caucasian population frequency of the minor alleles. gDNA was extracted from the plasma buffy coat by a Qiagen kit, followed by TaqMan genotyping assays (Applied Biosystems). The NAF and serum level of estradiol (E2), estrone (E1), progesterone (P4), testosterone (T), androstenedione (A4), and dehydroepiandrosterone (DHEA) were measured by immunoassay. Hormone levels were compared across genotype groups using the ANCOVA in SAS (age-adjusted significance p &lt; 0.05). Results: (See the Table) Conclusions: There is no data yet to show that NAF hormone content is related to breast cancer risk. This hypothesis will be tested in our on-going study. Locally regulated biosynthesis and clearance of hormones from the breast seems likely. Our data support such a phenomenon, since NAF correlations with functional enzyme SNPs are more frequent than with serum. The significant relationships between SNPs and NAF hormones, not seen with the same serum hormone, support the notion that they are determinants of breast cancer risk.

Abstract 4477: Progesterone (P4) and testosterone (T) concentrations in random fine needle aspirates of the breast in pre- and postmenopausal women

Background: The availability of steroid hormones in the breast may be an important measure of the potential for proliferation of hormone-dependent breast cancer, and because retention of hormones may be influenced by serum levels, in situ formation, and the presence of binding proteins and lipids in the tissue, measurements of tissue concentrations are more informative than serum concentrations alone. Methods: Subjects were normal women, aged 36-65 yr, without breast cancer and not taking hormones. Tissue was obtained by fine needle aspiration of the breast. The cellular pellet was saved for analysis of DNA, and lipids were extracted from the supernatant including the fatty layer. Previous work had shown the cellular pellet contained a very little of the total steroids of the sample. Triglycerides were precipitated from 90% methanol at –20 °C and the remaining lipids were applied to a C18 HPLC column for purification in a gradient of methanol and acetonitrile in phosphate buffer. Fractions containing P4 and T were analyzed by immunoassays. The total DNA in the cellular pellet was isolated and quantified by UV absorbance. The steroid content was expressed as either per mg of purified lipid or per microgram of DNA. The data, when expressed as the natural log of the concentrations, followed a normal distribution. Differences in pre- and postmenopausal concentrations were analyzed by group t-tests. Results: The geometric means of the hormone concentrations are shown in the table. Comment: Despite the almost complete loss of progesterone in serum of postmenopausal women, the concentrations in the tissue are reduced but remain, on average, at more than 25% of the premenopausal level, somewhat more than the previously reported percentage in NAF of 5%. Relationships within individual women to other risk factors will be explored. Testosterone is also maintained at a relatively high level in the tissue of postmenopausal women, and may serve as a substrate for aromatase.

Abstract 5756: Protein biomarkers for breast cancer risk are specifically correlated with local steroid hormones in nipple aspirate fluid

Background: Breast cancer risk is related to endogenous lifetime steroid hormone exposure. The local production of steroid hormones in the breast is a stable contributor to the hormonal environment. Several risk marker proteins have been identified in nipple aspirate fluid (NAF) in unaffected contralateral breast or in high-risk subjects as indicators of changes in breast on oxidative stress (superoxide dismutase), inflammation (C-reactive protein and YKL40), protease activity (cathepsin D) and growth factors (bFGF). However, it is not clear whether the alteration of protein markers is related to the local steroid hormone synthesis and metabolism in the breast. In the study, we studied the correlation between protein markers and both systematic (serum) and local (NAF) abundance of hormones. Methods: NAF and blood samples were obtained from normal breast of 54 healthy women and from unaffected breast of 60 breast cancer patients. The 114 subjects consisted of 48 women in premenopausal, 54 in postmenopausal and 12 in perimenopausal. The abundance of five protein markers (SOD1, CRP, YKL40, CatD and bFGF) was measured using ELISA. The NAF concentration of estradiol (E2), estrone (E1), progesterone (P4), andostenedione (A4), testosterone (T), dehydroepiandrostrerone (DHEA) and DHEA sulfate (DHEAS), and the serum concentration of E2, E1, P4, A4, T, DHEA and follicular-stimulating hormone (FSH) were measured using ELISA or RIA. The correlation between protein markers and hormones were examined using Spearman's rank correlation test with Bonferroni adjusted p &lt; 0.05 as statistical significant. Results: The correlation among the protein markers showed that SOD1 was significantly correlated with CRP (r=0.276, p=0.033) and catD (r=0.340, p=0.0036). bFGF was significantly correlated with CRP (r=0.343, p=0.0021), indicating these proteins may be affected each other in the breast. The relationship between protein markers and hormones indicated that protein markers did not have much correlation with serum hormones, except bFGF was negatively correlated with serum T level (r=−0.339, p=0.017). In contrast, protein markers showed stronger correlation with multiple estradiol precursors in NAF. Specifically, SOD1 correlated with DHEA (r=0.333, P=0.019) and DHEAS (r=0.372, p=0.0030). YKL40 correlated with NAF T level (r=0.389, p=0.0012). CatD correlated with NAF DHEAS (r=0.400, p=0.0014). bFGF negatively correlated with NAF T (r=−0.339, p=0.015). CRP did not show significant correlation with any types of measured NAF hormones. Conclusions: NAF protein markers were more strongly related to local hormone levels in the breast, rather than systematic hormones in the blood. Protein markers were specifically correlated with different components of hormone hormones, suggesting that metabolic precursors may contribute to breast cancer risk through distinct mechanisms.

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 5756. doi:1538-7445.AM2012-5756

Soy isoflavone supplementation for breast cancer risk reduction: a randomized phase II trial

Soy isoflavone consumption may protect against breast cancer development. We conducted a phase IIB trial of soy isoflavone supplementation to examine its effect on breast epithelial proliferation and other biomarkers in the healthy high-risk breast. One hundred and twenty-six consented women underwent a random fine-needle aspiration (rFNA); those with 4,000 or more epithelial cells were randomized to a double-blind 6-month intervention of mixed soy isoflavones (PTIG-2535) or placebo, followed by repeat rFNA. Cells were examined for Ki-67 labeling index and atypia. Expression of 28 genes related to proliferation, apoptosis, and estrogenic effect was measured using quantitative reverse transcriptase PCR. Hormone and protein levels were measured in nipple aspirate fluid (NAF). All statistical tests were two-sided. Ninety-eight women were evaluable for Ki-67 labeling index. In 49 treated women, the median Ki-67 labeling index was 1.18 at entry and 1.12 post intervention, whereas in 49 placebo subjects, it was 0.97 and 0.92 (P for between-group change: 0.32). Menopausal stratification yielded similar results between groups, but within premenopausal soy-treated women, Ki-67 labeling index increased from 1.71 to 2.18 (P = 0.04). We saw no treatment effect on cytologic atypia or NAF parameters. There were significant increases in the expression of 14 of 28 genes within the soy, but not the control group, without significant between-group differences. Plasma genistein values showed excellent compliance. A 6-month intervention of mixed soy isoflavones in healthy, high-risk adult Western women did not reduce breast epithelial proliferation, suggesting a lack of efficacy for breast cancer prevention and a possible adverse effect in premenopausal women.

P3-04-03: Identification of Hormone-Responsive Genes as Biomarkers for Menstrual Cycle Phases and Menopausal Status

Background

The definition and validation of biomarkers in archived breast tissue samples for prognostic research is limited by the fact that the exact menstrual cycle phases and menopausal status at the time of tissue sampling is often unknown or not accurate by patient survey. Biomarkers that vary with menstrual cycle phases in premenopausal women would be difficult to standardize. There are also significant differences in gene expression in pre- and post-menopausal women. Therefore, menstrual cycle fluctuation and menopausal status need to be considered for all candidate biomarkers as part of the validation process. The aim of this study is to identify genes responsive to different hormones to accurately define menstrual cycle phases and menopausal status.

Methods: We studied gene expression profiles of 18 random fine-needle aspirate (rFNA) samples from unaffected contralateral breast (8 pre-menopausal, mean age 44.5; 10 post-menopausal, mean age 58.8) and investigated the correlation between gene expression and serum hormone levels of estradiol (E2), progesterone (P4) and follicle stimulating hormone (FSH). Genes that were highly correlated with the serum levels of each hormone (Pearson correlation coefficient r &gt; 0.60) were considered as specific hormone-responsive genes (P &lt; 0.0085). The combined gene profiles of hormone-responsive genes were used to dissect samples in different menstrual cycle phases and menopausal status. Selected genes related to mammary gland development and hormone regulation based on gene function and gene network analysis were validated using qRT-PCR in 18 original rFNA samples and in 28 independent samples.

Results: From 35,964 genes and 12,838 undesignated transcripts, we identified genes/transcripts highly correlated with E2 (1091 genes), P4 (127 genes) or FSH (58 genes). The most significantly correlated genes in each group were selected to define four panels of genes: Panel A-21genes stimulated by E2 (r &gt; 0.78); Panel B-22 genes stimulated by P4 (r &gt; 0.75); Panel C-7 genes stimulated by FSH (r &gt; 0.65); and Panel D-10 genes suppressed by FSH (r &lt; −0.65). Hierarchical clustering analysis using the combination of gene panels dissected the samples into four clusters based on three phases of menstrual cycles and post-menopausal status. Specifically, high panel C and low panel D expression segregated post- from pre-menopausal samples. Low expression of panel A and B genes dissected early follicular phase from late follicular and luteal phases, while higher expression of panel B genes discriminated luteal phase from late follicular samples.

Conclusion: Our results indicate that the menstrual cycle phases and menopausal status determined by age, patient survey and serum hormone concentrations are reflected in the expression of specific gene sets in the normal breast. The combination of hormone-responsive gene panels would allow the classification of breast samples regarding to the menstrual phases and menopausal status at the time of sampling. It would also facilitate the selection and validation of breast cancer biomarkers that are independent of menstrual cycle fluctuation and menopausal variation for clinical use.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-04-03.

P4-11-09: Polymorphisms Related to Steroid Hormone Concentrations in Nipple Aspirate Fluid (NAF)

Background

The steroid hormone concentrations in NAF are variable, and differ significantly from systemic levels. Single nucleotide polymorphisms (SNPs) in genes associated with the metabolism of estradiol (E2) to 4-hydroxyestradiol (CYP1B1) and a transporter of steroid sulfate uptake (SLCO2B1) may partially determine the steroid hormone level in NAF, and thereby contribute to breast cancer risk. We determined the relationship between SNPs of interest and the measured concentrations of sex steroids in NAF.

Methods: Blood samples of 263 women at high risk of breast cancer who produced NAF were extracted for gDNA, and 40 ng of gDNA was used to determine the presence of the selected SNPs or their wild type genes in all subjects by the Taqman Drug Metabolism genotyping assays (Applied Biosystems). The concentrations of six steroid hormones, estradiol(E2), estrone (E1), progesterone (P4), testosterone (T), androstenedione (A4), and dehydroepiandrosterone (DHEA), from NAF were measured by immunoassay procedures after extraction and purification by High Pressure Liquid Chromatography. Comparisons of NAF steroid hormone concentrations were made for the polymorphism and wild type groups using the nonparametric Mann-Whitney tests (significance p &lt; 0.05, two-tailed).

Results: 46% of the subjects carried the V432K polymorphism of CYP1B1 (rs 1056836, C&gt;G), and 45% of the subjects carried the S486F polymorphism of SLCO2B1 (rs 2851069, C&gt;T). All NAF hormone concentrations are represented as a median with the quartile range (25%, 75%). The NAF P4 levels of the V432K mutation carriers of CYP1B1 were significantly lower than those of subjects with the wild type alleles: 3.54(1.62, 8.79) ng/mL and 7.65(2.13, 27.77) ng/mL, respectively (p = 0.002). Those with the S486F polymorphism of SLCO2B1 had significantly higher E1 levels than the wild type subjects: 0.35(0.14, 1.12) ng/mL and 0.25(0.11, 0.59) ng/mL, respectively (p = 0.026) and significantly lower P4 levels: 3.77(1.71, 11.53) ng/mL and 6.65 (2.34, 22.24) ng/mL, respectively (p=0.021). In addition, we found that the women carrying both the V432K and S486F mutations had significantly lower P4 levels than the women carrying only the S486F mutation: 2.43(1.45, 6.67) ng/mL and 6.94(2.13, 26.64) ng/mL (p=0.013). No associations were found between the other hormones and these polymorphisms.

Conclusions: The anticipated effects of CYP1B1 in increasing clearance of E2 and E1 were not observed. Instead, NAF E1 concentrations were significantly increased. In subjects with the S486F polymorphism of SLCO2B1 the expected decrease in E1 and E2 in NAF was not observed; nor was the DHEA concentration decreased. These expectations were based on the reported lower activity of the S486F gene product. The decreased concentrations of NAF P4 associated with both polymorphisms are difficult to explain. Additional studies are required to understand the observed associations, but these findings raise the possibility that low P4 levels in NAF may be genetically determined, and suggest the hypothesis that this polymorphism may be related to a decreased risk of breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-11-09.

P5-01-09: Differences in Serum Estradiol and Prolactin Concentrations in Women Who Yield Nipple Aspiration Fluid and Those Who Do Not

Introduction: Nipple aspiration fluid, NAF is an important biosample for breast cancer research, but its utility is limited by the fact that the fraction of NAF-yielders varies from 35% to 90% in various studies. NAF yielders (Y) and non-yielders (NY) are known to differ in demographic characteristics, but the systemic endocrine profiles of Y and NY populations have not been studied, and may affect the generalizability of findings in studies of NAF.

Methods: A subset of participants from an ongoing case-control study was included (120 cases, 120 controls). Cases are women presenting to the Lynn Sage Breast Center with newly diagnosed unilateral breast cancer, and controls are women presenting to the Lynn Sage Mammography Center who do not have cancer. NAF collection was attempted on all consented subjects; those yielding ≥2 uL NAF were designated as Y and those yielding &lt;2 uL NAF were NY (120 Ys, 120 NYs). Menopausal status, age, race, menstrual cycle phase, mammographic density, and serum hormone levels were also collected. Differences between Y and NY groups were tested using a t-test for age, χ2 for race, and Wilcoxon Sum Rank Test for serum hormone levels. Mammographic density was quantitated using digital or digitized images and the CUMULUS software. Linear regression was used to test the relationship between a logged serum hormone values and if a patient yielded adjusting for phase of menstrual cycle in premenopausal women.

Results: Mean ages of Ys and NYs were not different 51.0 and 52.6, respectively (p=0.11). The distribution of Ys by race (Caucasian, African American, other), was not different (χ2 p=0.58). Median serum prolactin concentrations were higher in Ys than NYs for both pre- (7.0 and 2.5 ng/ml) and post-menopausal (5.6 and 2.4 ng/ml) women, respectively (both p&lt;0.01). Median serum estradiol was lower in yielding premenopausal patients only (pre- 90.5 and 64.3 pg/ml p=0.02; post- p=0.59). Stratifying the premenopausal women further into cases and controls, the difference only held for cases and not for controls (p=0.02, p=.033). In the premenopausal patients the regression models suggested that these relationships for estradiol and prolactin remain even after adjusting for phase of the menstrual cycle. No differences in Ys versus NYs were found for progesterone, follicle stimulating hormone, or sex hormone binding globulin. Mammographic density was not different for Ys as compared to NYs for pre- (22% and 20%, p=0.83), but was marginally lower for post-menopausal Ys versus NYs (11% and 15% density; p=0.07). Following stratification of the postmenopausal women into cases and controls, the cases who yielded had significantly lower than NYs (11% and 19% density, p=0.03), but the control Ys and NYs were not different (10% and 11% density, p=0.65).

Conclusion: Pre- and post-menopausal women who yield NAF display increased serum prolactin levels, whereas decreased estradiol levels were observed in premenopausal NAF Ys. These findings suggest that NAF yield has systemic endocrine determinants, with implications for biomarker research on NAF samples. Further characterization of Y and NY women is important, along with standardization of methods of NAF collection, since NAF yield varies widely between studies.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-01-09.

In vitro human skin permeation of endoxifen: potential for local transdermal therapy for primary prevention and carcinoma in situ of the breast

PURPOSE

Oral tamoxifen, a triphenylethylene (TPE), is useful for breast cancer prevention, but its adverse effects limit acceptance by women. Tamoxifen efficacy is related to its major metabolites 4-hydroxytamoxifen (4-OHT) and N-desmethyl-4-hydroxytamoxifen (endoxifen [ENX]). Transdermal delivery of these to the breast may avert the toxicity of oral tamoxifen while maintaining efficacy. We evaluated the relative effciency of skin permeation of 4-OHT and ENX in vitro, and tested oleic acid (OA) as a permeation-enhancer.

METHODS

4-OHT, ENX, and estradiol (E2) (0.2 mg/mL of 0.5 μCi (3)H/mg) were dissolved in 60% ethanol-phosphate buffer, ±OA (0.1%-5%). Permeation through EpiDerm™ (Matek Corp, Ashland, MA) and split-thickness human skin was calculated based on the amount of the agents recovered from the receiver fluid and skin using liquid scintillation counting over 24 hours.

RESULTS

In the EpiDerm model, the absorption of 4-OHT and ENX was 10%-11%; total penetration (TP) was 26%-29% at 24 hours and was decreased by OA. In normal human skin, the absorption of 4-OHT and ENX was 0.3%; TP was 2%-4% at 24 hours. The addition of 1% OA improved the permeation of ENX significantly more than that of 4-OHT (P < 0.004); further titration of OA at 0.25%-0.5% further improved the permeation of ENX to a level similar to that of estradiol.

CONCLUSION

The addition of OA to ENX results in a favorable rapid delivery equivalent to that of estradiol, a widely used transdermal hormone. The transdermal delivery of ENX to the breast should be further developed in preclinical and clinical studies.

Abstract 5566: In vitro human skin permeation enhancement of endoxifen by oleic acid

Background: Oral medication for breast cancer prevention is associated with systemic exposure and resulting adverse effects; there is a need for alternative drug delivery approaches. Transdermal drug delivery is such an option, and 4-Hydroxy-N-desmethytamoxifen (endoxifen, ENX) is an excellent candidate for development for this route. ENX is an active metabolite of tamoxifen with major therapeutic effect related to potent estrogen antagonism and ability to cause proteosomic degradation of ERα. We hypothesize that skin permeation of ENX with oleic acid (OA) will be equivalent or superior to that of estradiol (E2), which is a well-established transdermal agent.

Methods: Split-thickness human skin samples (354 ± 25 micron) were prepared from de-identified fresh mastectomy specimens under an IRB approved protocol using a surgical blade and placed in Franz diffusion cells (PermeGear, Inc.). ENX was prepared in 60 % (v/v) ethanol/phosphate buffer (PB) +/- OA (0.1to 1% v/v). E2 was used as a positive control drug, prepared in 60 % ethanol/PB. The receiver fluid was PBS, pH 7.4 with 4% (w/v) polyoxyethylene 20 oleyl ether (Sigma-Aldrich). 100 µL of the drug solution (30 µg + 0.1µCi of 3H-E2 or 3H-ENX) was loaded in the donor chamber. Receiver fluid was stirred at 37° C. A sample of receiver fluid was collected for 3H counting from 4 to 24 hr point with 2 hr interval. Each permeation experiment was performed in duplicate for each treatment condition using the breast skin of one individual. The permeation experiments were repeated three times with the skin from different individuals.

Results: Results were expressed as the mean and standard deviation (SD) of the % of the applied dose. Absorption is defined as the amount of drug passing into the receiver fluid. We found that the absorption of E2 was 0.2 ± 0.17% (at 12hr) and 3.16 ± 2.79 % (at 24hr) of the applied dose while the absorption of ENX was 0.07± 0.08 % (at 12hr) and 1.45 ± 1.07 % (at 24hr). In the presence of OA, the permeation of ENX was enhanced by 2 to 12- fold at 12 hr and by 1.2 to 3.8- fold at 24 hr. At the 12 hr point, the absorption of ENX alone is one third of that of E2 alone (p = 0.09) however in the presence of 0.25, 0.5, and 1% (v/v) of OA, the absorption of ENX was by 4.4-fold (p = 0.02), 6.4-fold (p = 0.01), and 3-fold (p = 0.02) higher than E2, respectively. At 24 hr, there was no further significant enhancement in the absorption of ENX by 0.25 and 0.5% of OA compared to that of E2. The addition of 0.1 and 1% OA made the absorption of ENX retarded than that of E2 at 24 hr.

Conclusion: The skin permeation of ENX was significantly enhanced in the presence of 0.25-1 % of oleic acid and was superior to that of E2 alone at 12 hr. Our results imply that the topical delivery of endoxifen is a potential option for breast cancer prevention with no or minimal systemic toxicity/side effects. Efficacy remains to be demonstrated, but is highly likely given the data on the parent compound (tamoxifen).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5566. doi:10.1158/1538-7445.AM2011-5566

Abstract P2-06-20: Hormonal Criteria for Assessment of Menopause: Role of Anti-Mullerian Hormone

Introduction: The difficulty in establishing the time of menopause poses a problem in many breast cancer research studies. We sought to determine the value of adding anti-mullerian hormone (AMH) to the accuracy of designating hormonal signs of menopause in 179 women who were recruited for a case-control study of nipple aspirate fluid (NAF) biomarkers.

Methods: A questionnaire was administered to obtain medical and reproductive history, self-reported menstrual cycle length, last menstrual period and age. Serum estradiol, progesterone, FSH, and AMH were measured in a blood sample obtained on the day of the study encounter. Criteria for premenopause were: serum FSH &lt;30 mIU/ml, AMH &gt;0.08 ng/ml, estradiol (E2) &gt;30 pg/ml, and menstrual periods of 25 to 35 days. For postmenopause the inverse of the hormone levels and no menstrual periods for &gt;12 mo and age &gt;52 years was used. Serum progesterone (P4) concentration of &lt;3 ng/ml provided confirmation of postmenopause. Results: The age range was from 35 to 69 years (median 51). By self-report (amenorrhea &gt;12 mo and age) 76 subjects were premenopausal; 70 were postmenopausal and 33 subjects were perimenopausal. Table: Designation of menopausal state based on hormonal criteria: Concordance of individual measures with the designation based on all criteria (percentages).

Table

FSH was found to be discordant in 1 (1.1%) of premenopausal subjects and in 5 (5.3%) of postmenopausal subjects. AMH was found to be discordant in 21 (24.7%) of premenopausal subjects and 6 (6.4%) of postmenopausal subjects. Estradiol was discordant in 13 (15.3%) of premenopausal subjects and in 7 (7.4%) of postmenopausal subjects. Progesterone was &lt;3 ng/ml in all of the postmenopausal subjects. The combination of FSH and AMH predicted 100% of the grouping based on all measures; FSH and E2 predicted 99.9%. The absence of progesterone is a certain criterion for postmenopause but adds nothing to the designation of premenopause. Comment: An accurate determination of the hormonal and reproductive status of women is critically important in studies relating hormones to breast cancer risk. The loss of ovarian hormones has long-term implications, and the menopausal status at the time of sampling determines the recent and current hormonal exposure. Using the hormonal criteria, all women in this study could be classified as pre-or postmenopausal. Adding AMH to the usual hormones did not improve the designation based on the other criteria.

Abstract P6-10-02: Differential qRT-PCR-Based Gene Expression Signatures by Menopausal Status and Menstrual Phase in Random Fine-Needle Aspiration Samples from Healthy High-Risk Women

Background: The utility of archived breast tissue samples for risk-related research is limited by the fact that menopausal and menstrual status at the time of tissue sampling is often unknown. We evaluated the expression of a panel of genes in degraded RNA samples from women undergoing random fine-needle aspirate (rFNA) in preparation for a soy-isoflavone intervention. Our goal was to identify breast epithelial gene expression patterns related to menopause and menstrual phase.

Methods: Among 86 at high risk women (a 5-year Gail risk estimate &gt;1.6%, or a prior history of contralateral breast cancer but no systemic therapy), 46 were premenopausal (mean age 43.8 years) and 40 were postmenopausal (mean age 55 years). Stratification by menopause and menstrual phase was accomplished using menstrual dates and plasma estradiol (E2) and progesterone(P4) concentrations, measured by radioimmunoassay. 100 ng of RNA from baseline rFNA samples of the breast was reverse transcribed(mean RNA integrity 3.2). Amplicons of interest were linearly amplified to 10 cycles for 28 genes related to breast cancer and estrogen responsiveness. Assays were designed with small amplicons (&lt;100 bp) and qPCR reactions were carried out using the TaqMan Low Density Arrays (Applied Biosystems). For each gene of interest, expression levels were normalized to the average expression of GAPDH and HPRT1. The means, standard deviations, and 95% confidence intervals were calculated for plasma E2, P4, and gene expression difference between pre-and postmenopausal groups, and between the follicular and luteal phase within the premenopausal group were conducted using the unpaired t-test. P-values from gene expression difference were adjusted via the Benjamini-Hochberg (1995) approach.

Results: Within the premenopausal women group, there was no significant change in plasma E2 level between follicular and luteal phase groups (p=0.1756) while P4 level was higher in luteal phase (p=0.0474). The expression of five genes was significantly higher in the premenopausal than in the postmenopausal group: relative expression was 5-fold higher for progesterone receptor (PGR), 6-fold for pS2 (TFF1), 7-fold for gene regulated in breast cancer 1 protein (GREB1), 2-fold for prolactin receptor (PRLR) and 2-fold for CyclinD1 (CCND1) (adjusted p&lt; 0.026 for all). Within the premenopausal women group, the expression of ERα (ESR1) was one-third lower, and the signal peptide, CUB domain, EGF-like 2 (SCUBE2) was one-fifth lower in the luteal phase group compared to the follicular phase group (adjusted p=0.0423 for ESR1, p=0.0076 for SCUBE2).

Conclusion: Our findings suggest that the expression of genes related to estrogenic response in the breast epithelium of premenopausal women declines following menopause, whereas the relative suppression of ESR1 and SCUBE2 relate to effects of progesterone during the luteal phase of the menstrual cycle. These changes may allow the development of a model to date archived breast samples by menopausal and menstrual status.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-10-02.

Abstract B33: Serum hormone concentrations in women who yield breast nipple aspirate fluid (NAF) and those who do not

Objective: Determine whether differences in serum hormone concentrations explain the lack of NAF yield among women participating in a study of NAF hormone concentrations in breast cancer cases and screening controls.

Methods: 80 NAF yielders (Y) and 80 non-yielders (NY) were randomly selected from women who had completed participation in an ongoing case-control study, equally divided by menopausal status and case-control status (only the contralateral breast was aspirated in cases). Average age of premenopausal women was 45.95 years and of postmenopausal women was 57.54 years. The percentage of African American and Caucasian subjects was similar among those who yielded NAF and those who did not. Serum was collected on the same day that nipple aspiration was attempted and the serum was assayed for estradiol, progesterone, and FSH by standard immunoassays. Hormonal concentrations were compared among 80 subjects who produced &gt;2 microliters of NAF and 80 who did not. Wilcoxon tests were used to compare rank distributions of the values for yielders and non-yielders within each menopausal and case/control category.

Results: Hormonal data were analyzed in quintiles with the following comparisons: premenopausal cases Y vs NY; postmenopausal cases Y vs NY; premenopausal controls N vs NY; postmenopausal controls N vs NY. Among premenopausal cases estradiol was significantly greater at the P = 0.0067 level among those who did not produce NAF. This remained significant after correction for multiple comparisons. The difference remained significant after combining cases and controls at the P = 0.021 level. The other comparisons were not significant. Analyses of progesterone and FSH yielded no significant differences.

Discussion: The inhibition of breast fluid accumulation by estradiol is consistent with the effect of ovarian steroids on milk secretion observed after parturition. The observation that this effect was greater in cases is interesting and will be investigated further to ascertain whether other factors associated with breast cancer may play a role in the observed inhibition.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):B33.

Cellular and hormonal content of breast nipple aspirate fluid in relation to the risk of breast cancer

In research settings, the measurement of serum and urine hormone concentrations has shown modest positive relationships with breast cancer risk in postmenopausal women. However, the local production of sex steroids in the breast is a significant contributor to the hormonal environment of the breast. Nipple aspiration fluid provides a window into this environment and allows the measurement of hormone and protein content which may show stronger relations to breast cancer risk, and therefore enable both more accurate risk assessment, and the use of preventive measures directed to the lowering of local breast hormonal exposure.

Abstract 2907: Endoxifen, a potential alternative to 4-OHT gel for chemoprevention

Background: Topical application of 4-hydroxytamoxifen (4-OHT) to the breast has been reported to inhibit breast tumor cell proliferation to the same degree as the standard dose of oral tamoxifen (TAM) and results in substantially lower systemic effects. Recently, 4-Hydroxy-N-desmethytamoxifen (endoxifen, ENX), another active anti-estrogenic metabolite of TAM has been reported to give a major therapeutic effect because of its abundance and ability to cause proteosomic degradation of ERα. We hypothesize that transdermal permeation of ENX will be significantly enhanced by chemical permeation enhancers (CPEs), making it superior to that of 4-OHT. For the first time, we are reporting the skin permeation of ENX compared to 4-OHT using split-thickness skin of human breast.

Methods: De-identified human skins were obtained from mastectomy specimens with IRB approval. The split-thickness skin were prepared using a surgical dermatome from fresh skin and placed in the MatTek Corp. permeation device (MPD). Procedures for permeation studies were followed as recommended by MatTek Corp. 4-OHT and ENX were prepared in 60 % ethanol/phosphate buffer +/− oleic acid (OA). The receiver solution was phosphate buffered saline (PBS), pH 7.4. 200 µL of the drug solution (40 µg + 0.1µCi of 3H-4-OHT or 3H-ENX) was loaded in the donor chamber. Receiver solutions were stirred at 37° C. The samples of receiver solutions at 24 hr were collected for 3H counting. The percent permeation of the 3H-4-OHT and 3H-ENX was calculated based on the ratio of the amount of 3H-drugs recovered from the receiver to total dose loaded on donor chamber. All permeation experiments were performed in triplicate with a minimum of 4 skin replicates.

Figure 1. Percent permeation of 4-OHT and ENX using split-thickness human skin at 24 h.

Results: Our permeation study using split-thickness skin samples showed relatively small and consistent intra/inter- batch variance in permeation experiments. (figure 1). We found that although the permeation of 4-OHT alone is two-fold higher than that of ENX alone (p=0.006), in the presence of 1 to 2.5% (v/v) of OA, the permeation of ENX was improved by 5 to 7-fold compared to that of ENX alone (p=0.000) and was 2-fold higher than that of 4-OHT+OA (p=0.000). Although the permeation of ENX with OA cotreatment is 1.4%, this is four-fold higher than that of the 4-OHT topical gel being used in a NIH-sponsored clinical trial.

Conclusion: We have found that transdermal permeation of ENX was significantly enhanced in the presence of oleic acid and was superior to that of the 4-OHT topical gel being tested in a current clinical trial. We have been actively screening other CPEs and nano-particles for improving ENX permeation. In addition, we will shortly initiate studies to validate anti-tumor efficacy of ENX in an appropriate animal model for transdermal delivery.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2907.

A prospective study of variability in mammographic density during the menstrual cycle

Mammographic breast density has been proposed as a surrogate endpoint in breast cancer prevention studies, but little is known about its variability over time, particularly in relation to menstrual cycle phase. The purpose of this study was to assess variation in breast density on digital mammograms using quantitative and qualitative density measures. Menstrual cycle phase was determined by salivary estradiol and progesterone assays. 73 healthy subjects with regular menses had 1-3 mammograms with paired saliva collection during a 12-month period. The mean difference in density as a percentage of the mean density was calculated for follicular-luteal (n = 50), luteal-luteal (n = 26) and follicular-follicular (n = 23) pairs in the same woman using the same breast. Two density measures (measurement of dense area and BIRADS) were used. The mean luteal density exceeded the mean follicular density by 7.1-9.2%, but density differences between luteal pairs and follicular pairs did not exceed 5%. The intraclass correlation for measurement of dense area was greater than 85% in all phases of the menstrual cycle, but was below 50% for BIRADS for luteal-follicular and follicular-follicular pairs. Our study provides estimates of the amount of variation in mammographic density during the menstrual cycle, and that inherent in repeated density measurement in premenopausal women, and suggests that menstrual phase of mammographic evaluation should be controlled for in intervention studies where density is being used as a surrogate measure.

Association of Serum Prolactin and Oxytocin With Milk Production in Mothers of Preterm and Term Infants

The present study was designed to compare milk production and hormone responses (prolactin [PRL], oxytocin [OT]) and to determine associations of hormone levels with milk production in mothers of preterm (PT) and term (TM) infants during the first 6 weeks postpartum. Mothers of PT infants ( n = 95) were all pump dependent; mothers of TM infants ( n = 98) were all feeding their infant at breast. Mothers of nonnursing PT infants produced less milk over time compared to mothers of TM infants. A higher proportion of PT mothers had lower basal PRL levels compared with TM mothers. PRL and frequency of breast stimulation combined positively influenced milk production in PT mothers. OT levels were higher in PT versus TM mothers, but OT was not related to milk production. Further study is warranted regarding interventions to enhance milk production, particularly in pump-dependent mothers of PT infants.