Breast cancer incidence in postmenopausal women with osteoporosis or low bone mass using arzoxifene

The Generations trial, a multicenter, placebo-controlled, double-blind trial, compared arzoxifene 20 mg/day and placebo in 9,354 postmenopausal women with osteoporosis (N=5,252) or low bone mass (N=4,102). Primary outcomes were vertebral fracture in the osteoporotic population and invasive breast cancer in all study participants. Here, we report the detailed breast cancer findings from the trial. Breast cancers were detected by annual mammograms and clinical examination. After 48 months follow-up, breast cancer incidence was compared between treatment groups by estrogen receptor (ER) and progesterone receptor (PR) status and baseline risk factors. Baseline breast cancer risk factors, including age, estimated Gail risk, and bone mineral density, were well balanced between treatment groups. A total of 75 breast cancers occurred 53 in the placebo group and 22 in the arzoxifene group (HR 0.41, 95% CI 0.25-0.68, P<0.001). There were 62 invasive breast cancers, 39 identified as invasive ER-positive (placebo 30, arzoxifene 9; HR 0.30, 95% CI 0.14-0.63, P=0.001) and 30 identified as invasive PR-positive (placebo 23, arzoxifene 7; HR 0.30, 95% CI 0.13-0.71, P=0.003). Breast cancer risk reduction with arzoxifene was similar between Gail risk groups (P interaction=0.31) and between low bone mass and osteoporosis groups (P interaction=0.35). Although generally well tolerated, there was a significant increase in venous thromboembolism, vasomotor symptoms, muscle cramps, and some gynecological events with arzoxifene. These findings demonstrate that in this study arzoxifene reduced the risk of ER-positive breast cancer in this population of postmenopausal women with low bone mass or osteoporosis, an effect similar to that seen with other SERMs.     

Effect of tibolone on breast cancer cell proliferation in postmenopausal ER+ patients: results from STEM trial.

PURPOSE: Tibolone is a selective tissue estrogenic activity regulator, approved for the treatment of vasomotor symptoms in postmenopausal women. We have done an exploratory, double-blind, randomized, placebo-controlled pilot trial to investigate the tissue-specific effects of 2.5 mg tibolone on breast cancer in postmenopausal women, in particular on tissue proliferation (STEM, Study of Tibolone Effects on Mamma carcinoma tissue). EXPERIMENTAL DESIGN: Postmenopausal women with initially stage I/II, estrogen receptor-positive (ER+) primary breast cancer, were randomly assigned to 14 days of placebo or 2.5 mg/d tibolone. Core biopsies of the primary tumor were obtained before and after treatment. Ki-67 and apoptosis index were analyzed in baseline and corresponding posttreatment specimen. RESULTS: Of 102 enrolled patients, 95 had evaluable data. Baseline characteristics were comparable between both treatment groups. Breast cancer cases are mainly invasive (99%), stage I or II (42% and 50% respectively), and ER+ (99%). Median intratumoral Ki-67 expression at baseline was 13.0% in the tibolone group and 17.8% in the placebo group, and decreased to 12.0% after 14 days of tibolone while increasing to 19.0% in the placebo group. This change from baseline was not significantly different between tibolone and placebo (Wilcoxon test; P=0.17). A significant difference was observed between the treatment groups when the median change from baseline apoptosis index was compared between the treatment groups (tibolone, 0.0%; placebo, +0.3%; Wilcoxon test; P=0.031). The incidence of adverse effects was comparable. CONCLUSIONS: In ER+ breast tumors, 2.5 mg/d tibolone given for 14 days has no significant effect on tumor cell proliferation.     

Reduction in proliferation with six months of letrozole in women on hormone replacement therapy

The objective of this study was to determine if 6 months of the aromatase inhibitor letrozole, administered to postmenopausal women taking a stable dose of hormone replacement remedy, would be safe and would modulate biomarkers of breast cancer risk. The intent was to reduce the proliferation marker Ki-67 while maintaining adequate systemic levels of estradiol so as to avoid perimenopausal symptoms. Postmenopausal women at high risk for development of breast cancer and taking a stable dose of estrogen or estrogen plus progestin were screened by random periareolar fine needle aspiration (RPFNA). To be eligible, the acquired breast epithelial cells had to be characterized as cytologic atypia or borderline atypia with ≥1,000 epithelial cells on the cytomorphology slide; plus ≥500 epithelial cells on a slide processed for Ki-67 immunocytochemistry. Forty-two women were enrolled in the one arm study and received 2.5 mg letrozole per day for 6 months, followed by repeat assessment of biomarkers. Ki-67 was reduced by a median relative value of 66%. There was no significant change in breast cell cytomorphology; ER weighted index score; serum estradiol, testosterone, or IGF-1:IGFBP-3 ratio; mammographic breast density, or frequency or severity of perimenopausal symptoms. Given the dramatic reduction in proliferation, the effect of letrozole on risk and response biomarkers should be explored further in a randomized, placebo-controlled Phase IIB breast cancer chemoprevention trial.     

Randomized, double-blind, multicenter trial comparing two doses of arzoxifene (LY353381) in hormone-sensitive advanced or metastatic breast cancer patients.

BACKGROUND: This randomized, double-blind, phase II study assessed two doses of the selective estrogen receptor modulator arzoxifene in women with advanced breast cancer. The primary end point was to choose the best of two doses of arzoxifene based on the response rate or the clinical benefit rate (CBR). Pharmacokinetics and toxicities were also assessed. PATIENTS AND METHODS: Ninety-two patients with advanced breast cancer received arzoxifene 20 or 50 mg/day. Tumor response was assessed using World Health Organization criteria. Toxicities were graded according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC) system. Pharmacokinetic data were analyzed using the NONMEM software program (GloboMax, Hanover, MD, USA). RESULTS: Response rates in the 20 mg arm were numerically higher than the 50-mg arm according to the investigator (40.5% versus 36.4%) and the independent review panel (42.9% versus 27.3%). CBR was higher in the 20 mg arm according to the investigator (64.3% versus 61.4%) and the independent review panel (59.5% versus 47.7%). Arzoxifene was well tolerated. There were no study drug-related deaths. Mean observed steady-state plasma concentrations of arzoxifene were 3.62 and 7.48 ng/ml for the 20 and 50 mg doses, respectively. CONCLUSIONS: There were no significant differences in efficacy or safety between 20 and 50 mg of arzoxifene. Accordingly, arzoxifene 20 mg/day was selected for further study in patients with breast cancer.     

Pharmacokinetics and tolerability of exemestane in combination with raloxifene in postmenopausal women with a history of breast cancer

Purpose: Raloxifene is a second-generation selective estrogen receptor modulator that reduces the incidence of breast cancer in postmenopausal women. Exemestane, a steroidal aromatase inhibitor, decreases contralateral new breast cancers in postmenopausal women when taken in the adjuvant setting. Preclinical evidence suggests a rationale for coadministration of these agents to achieve complete estrogen blockade. Experimental design: We tested the safety and tolerability of combination exemestane and raloxifene in 11 postmenopausal women with a history of hormone receptor-negative breast cancer. Patients were randomized to either raloxifene (60 mg PO daily) or exemestane (25 mg PO daily) for 2 weeks. Patients then initiated combination therapy at the same dose levels for a minimum of 1 year. Pharmacokinetic and pharmacodynamic data for plasma estrogens, raloxifene, exemestane, and their metabolites were collected at the end of single-agent therapy and during combination therapy. Results: Plasma concentration-time profiles for each drug were unchanged with monotherapy versus combination therapy. Raloxifene did not affect plasma estrogen levels. Plasma estrogen concentrations were suppressed below the lower limit of detection by exemestane as monotherapy and when administered in combination with raloxifene. The most common adverse events of any grade included arthralgias, hot flashes, vaginal dryness and myalgias. Conclusions: In this small study, coadministration of raloxifene and exemestane did not affect the pharmacokinetics or pharmacodynamics of either agent to a significant degree in postmenopausal women. The combination of estrogen receptor blockade and suppression of estrogen synthesis is well tolerated and warrants further investigation.     

Neoadjuvant percutaneous 4-hydroxytamoxifen decreases breast tumoral cell proliferation: a prospective controlled randomized study comparing three doses of 4-hydroxytamoxifen gel to oral tamoxifen.

PURPOSE: Two chemoprevention randomized studies using tamoxifen showed drug efficacy; however, adverse effects such as hot flushes, endometrial cancer, and above all, thromboembolism, remain a problem. 4 hydroxytamoxifen (4-OHT) is a very active metabolite of tamoxifen. This randomized study was designed to analyze if 4-OHT gel, administered percutaneously on the breast skin, can inhibit the proliferation of malignant breast cells to the same extent as orally administered tamoxifen. PATIENTS AND METHODS: Fifty-five postmenopausal women with an invasive estrogen receptor-positive breast cancer were randomly assigned to receive (for 2 to 3 weeks) either 4-OHT gel (0.5, 1, or 2 mg/d) or oral tamoxifen (20 mg/d) or no treatment. Response was evaluated using proliferation markers (Ki-67, proliferating cell nuclear antigen) and apoptosis markers in tissue samples obtained by Tru-cut biopsy before treatment, and at surgery after treatment. RESULTS: Administration of 4-OHT gel resulted in reductions in tumor tissue proliferation indexes (Ki-67 and PCNA), with approximate equivalence between the 1.0 mg/d or 2.0 mg/d 4-OHT dose, and oral tamoxifen, but had no effect on apoptotic markers. Plasma levels of 4-OHT were consistently higher in the oral tamoxifen group than in the gel groups. No dose-related pattern was shown for estrogen or progesterone receptor levels, and topical 4-OHT gel appeared to be generally well tolerated. Hot flushes are as common in the two higher gel doses as with tamoxifen. CONCLUSION: Percutaneous 4-OHT gel has a local impact on tumor proliferation. It could be tested in future prospective trials of chemoprevention or ductal carcinoma in situ adjuvant hormonotherapy.     

Effects of fulvestrant 250mg in premenopausal women with oestrogen receptor-positive primary breast cancer

Fulvestrant (Faslodex) reduces markers of hormone sensitivity and proliferation in postmenopausal women. This Phase II double-blind, randomised, multicentre study compared the effects of a single 250mg intramuscular dose of fulvestrant and placebo 14-21 days prior to surgery of curative intent on the oestrogen receptor (ER), progesterone receptor and Ki67 levels in 66 premenopausal women with ER-positive primary breast cancer. There were no statistically significant differences between fulvestrant and placebo with respect to any of the three markers analysed. The most common adverse events in both groups were nausea, headache and pyrexia. Fulvestrant 250mg had no effects on markers of hormone-sensitivity and proliferation in premenopausal women with primary breast cancer when measured at 14-21 days after injection. These findings suggest that a higher fulvestrant dose may be required in this patient population. Further clinical trials are necessary to evaluate the efficacy of fulvestrant in premenopausal women.     

Bone Mineral Density and Lipid Changes During 5 Years of Follow-up in a Study of Prevention of Breast Cancer with Toremifene in Healthy,High-risk Pre- and Post-menopausal Women

Summary A double-blind, randomised, placebo-controlled pilot study was initiated to evaluate the feasibility of chemoprevention with toremifene 60 mg/day in healthy women at high risk for breast cancer. Enrolment in the study was terminated earlier than planned because of slow patient accrual, although 13% of patients continued for 5 years. The revised efficacy outcomes were change in bone mineral density (BMD) from baseline at four skeletal sites, plus effects on serum lipids. In premenopausal women there was a trend for sustained increase in BMD during toremifene therapy after year 1 in lumbar spine. In postmenopausal women, toremifene had little or no effect on BMD trends. Levels of total and low-density lipoprotein (LDL) cholesterol were largely unchanged from baseline in premenopausal women treated with toremifene but were often slightly lower than in the placebo group during follow-up. Total and LDL cholesterol levels declined slightly from baseline in the postmenopausal women and were, at several points during the first 3 years, significantly lower than in the corresponding placebo group (p < 0.01). We conclude that: (a) assessment of toremifene 60 mg/day in chemoprevention will require further clinical trials; (b) toremifene 60 mg/day has no substantive negative effects on BMD in pre- or postmenopausal women and may exert a minor favourable influence (in particular, the effects of toremifene 60 mg/day on BMD in premenopausal women may make the drug an attractive alternative to tamoxifen 20 mg/day for that patient subset); (c) lipid effects of toremifene 60 mg/day are, at minimum, neutral and may be modestly favourable for reducing cardiovascular risk.     

Phase II, randomized, double-blind study of two dose levels of arzoxifene in patients with locally advanced or metastatic breast cancer.

PURPOSE: To select a daily dose of arzoxifene (LY353381), a selective estrogen receptor modulator, for use in future studies in women with locally advanced or metastatic breast cancer who are either potentially tamoxifen sensitive (TS) or tamoxifen refractory (TR). PATIENTS AND METHODS: This trial was a randomized, double-blind, phase II study of arzoxifene 20 mg (n = 55) and 50 mg (n = 57) in women with advanced or metastatic breast cancer. Patients were randomly assigned to balance for number of metastatic disease sites, prior tamoxifen therapy, and estrogen receptor status. The primary end point was tumor response rate (RR). Secondary end points included clinical benefit rate (CBR), time to progression (TTP), and toxicity. RESULTS: Forty-nine patients were TS and 63 were TR. According to independent review, among TS patients, RR was higher in the 20-mg arm than the 50-mg arm (26.1% v 8.0%), with a longer TTP (8.3 v 3.2 months; P >.05). Among the TR patients, response rate was the same in the 20-mg and 50-mg arms (10.3%) with similar TTP (2.7 and 2.8 months, respectively; P >.05). CBR was higher in the 20-mg arm than in the 50-mg arm among TS patients (39.1% v 20.0%) and TR patients (13.8% v 10.3%). Arzoxifene was well tolerated. Dose-dependent toxicity was not demonstrated. There were no deaths during study. CONCLUSION: Arzoxifene is effective in the treatment of TS and TR patients with advanced or metastatic breast cancer at the 20-mg and 50-mg dose levels. Toxicities are minimal, and the therapy is tolerated. The 20-mg dose seems to be at least as effective as the 50-mg dose. Accordingly, arzoxifene 20 mg/d was selected for further study in patients with breast cancer.     

Effect of raloxifene on breast cancer cell Ki67 and apoptosis: a double-blind, placebo-controlled, randomized clinical trial in postmenopausal patients.

PURPOSE: Raloxifene is a selective estrogen receptor (ER) modulator approved for prevention and treatment of postmenopausal osteoporosis. This is an exploratory study of raloxifene in primary breast cancer patients. Experimental Design: Postmenopausal women (50-80 years of age), with histological or cytological diagnosis of stage I or II primary breast cancer, were randomly assigned to 14 days of placebo, 60 mg/day raloxifene, or 300 mg twice daily (600 mg/day) of raloxifene. A core biopsy of the primary tumor was obtained before therapy, and a representative sample of the excised tumor was obtained from the operative specimen after treatment. Paired baseline and endpoint biopsies from each patient were analyzed for Ki67, apoptosis, and estrogen and progesterone receptors. Treatment group differences in efficacy measurements were primarily evaluated for baseline-to-endpoint change and percentage change using a one-way ANOVA with treatment as the fixed effect. RESULTS: Of 167 enrolled patients, 143 had evaluable efficacy data. Most breast cancer cases were invasive (98.6%), stage I (76.6%), and ER-positive (83.2%). In patients with ER-positive tumors, Ki67 increased 7% from baseline on placebo and decreased by 21% on 60 mg/day raloxifene (P = 0.015 versus placebo) and by 14% on 600 mg/day raloxifene (P = 0.064 versus placebo). Raloxifene did not affect apoptosis. ER decreased significantly with 60 mg/day or 600 mg/day raloxifene compared with placebo (P < 0.01 for each comparison). Raloxifene had no statistically significant effects on Ki67 among patients with ER-negative tumors. There were no treatment differences in adverse events. CONCLUSION: In this exploratory trial, 60 mg/day raloxifene showed a significant antiproliferative effect in ER-positive breast cancer, demonstrated by the decrease in Ki67, with no effect in ER-negative cancer. This provides support for raloxifene having a breast cancer preventive effect in postmenopausal women.     

Effects of estradiol with micronized progesterone or medroxyprogesterone acetate on risk markers for breast cancer in postmenopausal monkeys

The addition of the synthetic progestin medroxyprogesterone acetate (MPA) to postmenopausal estrogen therapy significantly increases breast cancer risk. Whether this adverse effect is specific to MPA or characteristic of all progestogens is not known. The goal of this study was to compare the effects of oral estradiol (E2) given with either MPA or micronized progesterone (P4) on risk biomarkers for breast cancer in a postmenopausal primate model. For this randomized crossover trial, twenty-six ovariectomized adult female cynomolgus macaques were divided into social groups and rotated randomly through the following treatments (expressed as equivalent doses for women): (1) placebo; (2) E2 (1 mg/day); (3) E2 + P4 (200 mg/day); and (4) E2 + MPA (2.5 mg/day). Hormones were administered orally, and all animals were individually dosed. Treatments lasted two months and were separated by a one-month washout period. The main outcome measure was breast epithelial proliferation, as measured by Ki67 expression. Compared to placebo, E2 + MPA resulted in significantly greater breast proliferation in lobular (P < 0.01) and ductal (P < 0.01) epithelium, while E2 + P4 did not. Intramammary gene expression of the proliferation markers Ki67 and cyclin B1 was also higher after treatment with E2 + MPA (P < 0.01) but not E2 + P4. Both progestogens significantly attenuated E2 effects on body weight, endometrium, and the TFF1 marker of estrogen receptor activity in the breast. These findings suggest that oral micronized progesterone has a more favorable effect on risk biomarkers for postmenopausal breast cancer than medroxyprogesterone acetate.     

Selective oestrogen receptor modulators/new antioestrogens: a clinical perspective

Following tamoxifen, the first selective oestrogen receptor modulator (SERM), a number of other antioestrogens have been developed. The first-generation SERMs exhibit cross-resistance with tamoxifen and have agonist effects on the uterus. Toremifene has equal efficacy to tamoxifen and may be useful as a tamoxifen alternative. Efficacy results for droloxifene and idoxifene were disappointing and their clinical development ceased. Response rates for second-generation SERMs such as raloxifene and arzoxifene are also not high, although raloxifene shows promise in the chemoprevention of breast cancer. Paradoxically, high-dose oestrogens are proving to be effective breast cancer treatment with similar responses to tamoxifen in postmenopausal women with advanced disease, although these drugs are not well tolerated. Fulvestrant is a new type of oestrogen receptor (ER) antagonist with no agonist effects, which binds, blocks and degrades the ER. Fulvestrant produces high response rates compared with the SERMs, is not cross-resistant with SERMs or aromatase inhibitors (AIs) and is equally as effective as the AI anastrozole in the treatment of postmenopausal women with advanced breast cancer who have progressed after prior antioestrogen therapy. Pure antioestrogens such as the ER antagonist fulvestrant provide opportunities for therapeutic sequencing with tamoxifen and AIs and offer exciting possibilities for the future treatment of breast cancer.     

Use of tamoxifen and raloxifene for breast cancer chemoprevention in 2010

Two selective estrogen receptor modulators, tamoxifen and raloxifene, have been shown in randomized clinical trials to reduce the risk of developing primary invasive breast cancer in high-risk women. In 1998, the U.S. Food and Drug Administration (FDA) used these studies as a basis for approving tamoxifen for primary breast chemoprevention in both premenopausal and postmenopausal women at high risk. In 2007, the FDA approved raloxifene for primary breast cancer chemoprevention for postmenopausal women. Data from the year 2010 National Health Interview Survey were analyzed to estimate the prevalence of tamoxifen and raloxifene use for chemoprevention of primary breast cancers among U.S. women. Prevalence of use of chemopreventive agents for primary tumors was 20,598 (95 % CI, 518-114,864) for U.S. women aged 35-79 for tamoxifen. Prevalence was 96,890 (95 % CI, 41,277-192,391) for U.S. women aged 50-79 for raloxifene. Use of tamoxifen and raloxifene for prevention of primary breast cancers continues to be low. In 2010, women reporting medication use for breast cancer chemoprevention were primarily using the more recently FDA approved drug raloxifene. Multiple possible explanations for the low use exist, including lack of awareness and/or concern about side effects among primary care physicians and patients.     

Fulvestrant in the treatment of postmenopausal women with advanced breast cancer

Fulvestrant is a new type of estrogen receptor antagonist with no agonist effects, and represents a valuable addition to the range of endocrine treatments available to treat postmenopausal women with advanced breast cancer. Fulvestrant binds, blocks and degrades the estrogen receptor, thereby retarding growth and progression of hormone-sensitive tumors. Two Phase III trials have demonstrated that fulvestrant is at least as effective as the third-generation aromatase inhibitor anastrozole in the treatment of advanced breast cancer following progression on antiestrogen therapy. In addition, a Phase III trial comparing fulvestrant with tamoxifen in postmenopausal women with advanced breast cancer showed similar efficacy and tolerability. Clinical trials are ongoing to evaluate different endocrine sequence options for postmenopausal women with breast cancer, and to evaluate the efficacy of fulvestrant in combination with anticancer agents that target other signaling pathways.     

Fulvestrant in the treatment of postmenopausal women with advanced breast cancer

Fulvestrant is a new type of estrogen receptor antagonist with no agonist effects, and represents a valuable addition to the range of endocrine treatments available to treat postmenopausal women with advanced breast cancer. Fulvestrant binds, blocks and degrades the estrogen receptor, thereby retarding growth and progression of hormone-sensitive tumors. Two Phase III trials have demonstrated that fulvestrant is at least as effective as the third-generation aromatase inhibitor anastrozole in the treatment of advanced breast cancer following progression on antiestrogen therapy. In addition, a Phase III trial comparing fulvestrant with tamoxifen in postmenopausal women with advanced breast cancer showed similar efficacy and tolerability. Clinical trials are ongoing to evaluate different endocrine sequence options for postmenopausal women with breast cancer, and to evaluate the efficacy of fulvestrant in combination with anticancer agents that target other signaling pathways.     

Indication of hysteroscopy in tamoxifen treated breast cancer patients

The aim of this study was to indicate the patients treated with tamoxifen for breast cancer in which hysteroscopy with biopsy should be considered mandatory. 414 breast cancer patients who underwent hysteroscopy with bioptic evaluation were enrolled in the study. 334 subjects were treated with 20 mg of tamoxifen daily as adjuvant therapy for six up to a hundred months. Of the remaining 80 control patients, which had not received tamoxifen, 30 were in premenopause (Group IA) and 50, in postmenopause (Group IIA). The tamoxifen-treated patients were subdivided in premenopausal (Group IB = 72 patients) and in postmenopausal (Group IIB = 262 patients) groups. All patients were further classified in asymptomatic or symptomatic groups considering whether uterine bleeding was absent or present. The evaluation of the endometrial mucosa was performed by office hysteroscopy. In group IIB patients presenting uterine bleeding, malignant lesions were found in 7.8% of the cases. The incidence of premalignant and malignant lesions in IIB patients treated for longer than 3 years (11.7%) was higher than that observed in IIB patients treated for less than 3 years (1.3%). There was a significant difference in terms of endometrial pathology between Group IIB (32.8%) and Group IIA (8%) (p < 0.001); and between Group IIB (32.8%) and Group IB (13.9%) women (p = 0.003). Among IA and IIA patients there were no cases of endometrial hyperplasia or cancer; on the contrary, in IB and IIB women, 2 and 22 cases of atypical hyperplasia were observed, respectively. All cases of endometrial cancer were observed in Group IIB and had a diagnosis of poor prognosis. In conclusion the hysteroscopy with biopsy should be considered the first diagnostic procedure to perform in tamoxifen-treated postmenopausal patients presenting uterine bleeding and in postmenopausal women treated for longer than 3 years. In premenopause, hysteroscopy should be proposed to women with ultrasonographic abnormalities and/or with uterine bleeding to patients at high risk for endometrial cancer.     

Past oral contraceptive use and current dietary soy isoflavones influence estrogen metabolism in postmenopausal monkeys (Macaca fascicularis)

Estrogen metabolism may play an important role in mammary carcinogenesis in postmenopausal women. We evaluated the effects of prior oral contraceptive (OC) treatment and current soy isoflavone consumption on endogenous estrogen metabolite concentration and biomarkers of tissue estrogen exposure in a monkey model. One hundred eighty-one female cynomolgus macaques were randomized to receive OC or placebo for 26 months premenopausally, then ovariectomized and randomized to one of three diets for 36 months: an isoflavone-depleted soy protein isolate (Soy-) diet, a diet containing soy protein isolate with a human equivalent of 129 mg isoflavone/d (Soy+), or a Soy- diet supplemented with conjugated equine estrogens (CEE+) at a human equivalent dose of 0.625 mg/d. Reverse-phase high-performance liquid chromatography directly coupled with tandem mass spectrometry was used to measure the concentrations of estrogen species in urine samples. Generally, prior OC treatment was associated with significantly reduced urinary estrogen metabolites (25-55% reduction; P<0.05 for each versus OC-). Animals that consumed isoflavones postmenopausally had increased urinary 2-hydroxyestrone and 16alpha-hydroxyestrone (50% and 56% increases, respectively), but reduced levels of 2-hydroxyestradiol, 2-methoxyestradiol, and 17-epiestriol (92%, 63%, and 66%, respectively), compared with animals fed a Soy- diet. Isoflavones did not have widespread effects on uterine or mammary proliferation biomarkers, whereas prior OC significantly reduced two of three proliferation end points in the endometrium. Premenopausal OCs may have long-term systemic effects on response to estrogen and its metabolism whereas postmenopausal dietary isoflavones may alter endogenous estrogen metabolism in a modest but selective manner.     

The efficacy of 9-cis-retinoic acid (aliretinoin) as a chemopreventive agent for cervical dysplasia: results of a randomized double-blind clinical trial.

9-Cis-retinoic acid (aliretinoin) is a pan-retinoid receptor agonist and has been demonstrated in preclinical models to have potent chemoprevention effects. The purpose of this study was to determine the utility of using aliretinoin as a chemoprevention agent in cervical dysplasia. Patients with histological evidence of cervical intraepithelial neoplasia (CIN) 2/3 were randomized in a double-blind manner to receive high-dose aliretinoin (50 mg), low-dose of aliretinoin (25 mg), or placebo daily for 12 weeks. Compliance and side effects were monitored at various time points during therapy. At the completion of therapy, all of the patients underwent a loop procedure. Histology of pretreatment biopsies was compared with that of loop specimens. One-hundred and fourteen patients with CIN 2/3 were enrolled in the study. In the 112 patients evaluable for toxicity, headache was the most common clinical side effect and was experienced more frequently (74%) in the high-dose aliretinoin group. Eight patients withdrew from the study before completion of study medication because of unacceptable side effects. In the 104 patients evaluable for efficacy, there was no statistical difference in the rate of regression among the placebo (32%), the low-dose aliretinoin (32%), and the high-dose aliretinoin (36%) groups. (P = not significant; power 0.06). Aliretinoin at these dosages and this schedule does not appear to result in significant regression rates in CIN 2/3 patients when compared with placebo. Headache is encountered frequently and may thwart efforts to increase the dose or duration of aliretinoin in future cervical cancer chemoprevention studies. The rate of histological regression in biopsied CIN 2/3 patients is high even over a short time interval, and emphasizes the importance of having a placebo arm and an adequate sample size in cervical dysplasia chemoprevention studies.     

A phase II breast cancer chemoprevention trial of oral alpha-difluoromethylornithine: breast tissue, imaging, and serum and urine biomarkers.

PURPOSE: A double-blind randomized Phase II chemoprevention trial of alpha-difluoromethylornithine (DFMO) was conducted in a group of women at high risk for development of breast cancer. DFMO is an irreversible inhibitor of ornithine decarboxylase, the limiting enzyme of polyamine synthesis that is often up-regulated in breast cancer. Experimental Design: Study entrants were required to have random periareolar fine-needle aspiration cytology prior to entry that exhibited hyperplasia or hyperplasia with atypia, as well as a mammogram and clinical breast exam judged as not suspicious for breast cancer and no clinical hearing loss. Subjects were randomized to 6 months of oral DFMO (0.5 g/m(2)/day) or placebo, followed by repeat fine-needle aspiration and biomarker assessment. The main study end point was an improvement in cytologic pattern. RESULTS: Of 119 subjects entered, 96% completed the study and were evaluable for the main study end point. A modest reduction (28%) in average total urine polyamines was obtained in the DFMO group, but there was no reduction in the spermidine:spermine ratio. There was no difference in cytologic improvement between DFMO and placebo. Likewise, there was no difference between DFMO and placebo for the secondary end points of breast molecular marker changes (immunocytochemical expression of proliferating cell nuclear antigen, p53, and epidermal growth factor receptor), mammographic breast density, serum insulin-like growth factor I: insulin-like growth factor binding protein 3 ratio, adverse events, quality of life indices, or subsequent cancer development. CONCLUSIONS: DFMO at a dose level of 0.5 g/m(2)/day administered for 6 months does not modulate breast risk biomarkers tested in this study.     

A pilot surrogate end point biomarker trial of perillyl alcohol in breast neoplasia.

PURPOSE: Efficient strategies to screen promising agents in early phase development are essential for rapid progress in breast cancer chemoprevention. We report our experience with the natural compound perillyl alcohol (POH) administered in a short-term surrogate end point biomarker (SEB) protocol, using the "window" between diagnostic and definitive surgery. EXPERIMENTAL DESIGN: Eligible patients included those with a diagnosis of atypical ductal hyperplasia, ductal carcinoma in situ, lobular carcinoma in situ, or invasive carcinoma (<3 cm in size) that required further surgery. Thirty-seven of 267 women screened were enrolled in the study (14%). Five women received single-dose POH (1.5 g/m2) 2 days before surgery, 16 received escalating doses of POH (1.2 g/m2 to 4.8 g/m2/day) for 2 days before surgery, and 16 served as untreated controls. Exploratory SEB analysis [estrogen receptor, progesterone receptor, proliferation, apoptosis, M6P/insulin-like growth factor (IGF)-2R, IGF1, IGF2 and transforming growth factor beta] was conducted before and after POH. RESULTS: Only a small portion of the population screened entered the study. Reasons for nonparticipation included protocol ineligibility, conflict of timing of surgery, miscellaneous logistical reasons, or patient's choice. POH administration was well tolerated and did not interfere with surgical management. The power to observe changes in candidate SEB was diminished by a 44% incidence of cases in which the index lesion was not present in the definitive surgical specimen. CONCLUSIONS: Preoperative POH exposure was safe and suitable for a more definitive phase II SEB study. Further investigations must overcome logistical obstacles to accrual, and they must focus on approaches to maximize tissue collection and to incorporate genomic analysis of target lesions.