Pilot trial of a gonadotropin hormone agonist with replacement hormones as a prototype contraceptive to prevent breast cancer

RAZOR: A Phase II Open Randomized Trial of Screening Plus Goserelin and Raloxifene Versus Screening Alone in Premenopausal Women at Increased Risk of Breast Cancer

Background: Ovarian suppression in premenopausal women is known to reduce breast cancer risk. This study aimed to assess uptake and compliance with ovarian suppression using the luteinizing hormone releasing hormone (LHRH) analogue, goserelin, with add-back raloxifene, as a potential regimen for breast cancer prevention.Methods: Women at ≥30% lifetime risk breast cancer were approached and randomized to mammographic screening alone (C-Control) or screening in addition to monthly subcutaneous injections of 3.6 mg goserelin and continuous 60 mg raloxifene daily orally (T-Treated) for 2 years. The primary endpoint was therapy adherence. Secondary endpoints were toxicity/quality of life, change in bone density, and mammographic density.Results: A total of 75/950 (7.9%) women approached agreed to randomization. In the T-arm, 20 of 38 (52%) of women completed the 2-year period of study compared with the C-arm (27/37, 73.0%). Dropouts were related to toxicity but also the wish to have established risk-reducing procedures and proven chemoprevention. As relatively few women completed the study, data are limited, but those in the T-arm reported significant increases in toxicity and sexual problems, no change in anxiety, and less cancer worry. Lumbar spine bone density declined by 7.0% and visually assessed mammographic density by 4.7% over the 2-year treatment period.Conclusions: Uptake is somewhat lower than comparable studies with tamoxifen for prevention with higher dropout rates. Raloxifene may preserve bone density, but reduction in mammographic density reversed after treatment was completed.Impact: This study indicates that breast cancer risk reduction may be possible using LHRH agonists, but reducing toxicity and preventing bone changes would make this a more attractive option. Cancer Epidemiol Biomarkers Prev; 27(1); 58-66. ©2017 AACR.

Steroidal contraceptives: effect on bone fractures in women

BACKGROUND

Steroidal contraceptive use has been associated with changes in bone mineral density in women. Whether such changes increase the risk of fractures later in life is not clear. However, osteoporosis is a major public health concern. Age-related decline in bone mass increases the risk of fracture, especially of the spine, hip, and wrist. Concern about bone health influences the recommendation and use of these effective contraceptives globally.

OBJECTIVES

To evaluate the effect of using hormonal contraceptives before menopause on the risk of fracture in women

SEARCH STRATEGY

We searched for studies of fracture or bone health and hormonal contraceptives in MEDLINE, POPLINE, CENTRAL, EMBASE, and LILACS, as well as in clinical trials databases (ClinicalTrials.gov and ICTRP). We wrote to investigators to find additional trials.

SELECTION CRITERIA

Randomized controlled trials were considered if they examined fractures, bone mineral density (BMD), or bone turnover in women with hormonal contraceptive use prior to menopause. Studies were excluded if hormones were provided for treatment of a specific condition rather than for contraception. Interventions could include comparisons of a hormonal contraceptive with a placebo or with another hormonal contraceptive. Interventions could also include the provision of a supplement versus a placebo.

DATA COLLECTION AND ANALYSIS

We assessed for inclusion all titles and abstracts identified through the literature searches with no language limitation. The mean difference was computed with 95% confidence interval (CI) using a fixed-effect model.

MAIN RESULTS

We found 13 RCTs, 2 of which used a placebo. No trial had fracture as an outcome but most measured BMD. Combination contraceptives did not appear to affect bone health. Of progestin-only methods, depot medroxyprogesterone acetate (DMPA) was associated with decreased bone mineral density, while results were inconsistent for implants. The two placebo-controlled trials showed BMD increases for DMPA plus estrogen supplement and decreases for DMPA plus placebo.

AUTHORS' CONCLUSIONS

Whether steroidal contraceptives influence fracture risk cannot be determined from existing information. Due to different interventions, no trials could be combined for meta-analysis. Many trials had small numbers of participants and some had large losses to follow up. Health care providers and women should consider the costs and benefits of these effective contraceptives. For example, injectable contraceptives and implants provide effective, long-term birth control yet do not involve a daily regimen. Progestin-only contraceptives are considered appropriate for women who should avoid estrogen due to medical conditions.

Chemoprevention of breast cancer

Breast cancer remains the second leading cause of malignancy-related death in women in the USA, regardless of advances in novel therapeutic agents. High priority should be given to research aimed at the study of pharmacological and natural compounds that could potentially prevent the development of breast cancer in susceptible patients. Tamoxifen has been shown to reduce the incidence of estrogen receptor-positive invasive breast cancer in women with a high risk of developing this condition by nearly 50%, and studies in osteoporosis have revealed a similar protective effect of raloxifene in postmenopausal women. The aromatase inhibitors are superior to tamoxifen in reducing the recurrence of breast cancer in postmenopausal women; large clinical trials are currently evaluating the chemopreventive effect of these agents. The list of agents with the potential for chemoprevention in breast cancer is extensive and continues to expand. There is an immense need to develop drugs that will decrease the incidence of estrogen receptor-negative breast cancer in women at high risk of developing the disease. Herein, we review the most important chemopreventive agents in breast cancer and clinical trials that have evaluated their efficacy.

Reduced mammographic density with use of a gonadotropin-releasing hormone agonist-based chemoprevention regimen in BRCA1 carriers

PURPOSE

Women with a BRCA1 mutation (BRCA1(mut)) need risk reduction options beyond mastectomy and oophorectomy. We evaluated the efficacy, safety, and tolerability of hormonal chemoprevention with a gonadotropin-releasing hormone agonist (GnRHA) with low-dose add-back steroids in BRCA1(mut) carriers.

EXPERIMENTAL DESIGN

The 12-month open label clinical trial used the GnRHA deslorelin, ultra-low-dose estradiol (E(2)), and replacement testosterone, administered via daily intranasal spray in premenopausal women with a BRCA1(mut), and intermittent oral medroxyprogesterone acetate. The end points included mammographic percent density, bone mineral density, endometrial hyperplasia, symptom inventory, and quality of life (Medical Outcomes SF-36 survey).

RESULTS

Six of eight BRCA1(mut) women (mean age, 30.3 years; range, 25-36 years) completed the study. Mammographic percent density was significantly reduced at 12 months (median absolute mammographic percent density decrease, 8.3%; P = 0.043), representing a 29.2% median reduction in mammographic percent density. Bone mineral density remained within reference limits for all participants; there were no cases of atypical endometrial hyperplasia and menses resumed within a median of 67 days (range, 35-110 days) after last drug treatment day. The treatment was well tolerated; hypoestrogenic side effects were minimal and transient; and there were no significant changes in quality of life.

CONCLUSIONS

The GnRHA deslorelin, with low-dose add-back steroids, was well tolerated and significantly decreased mammographic percent density in BRCA1(mut) carriers. This regimen may reduce breast cancer risk and improve the usefulness of mammographic surveillance by reducing density. This is the first demonstration, to our knowledge, of a direct reduction of mammographic densities in young BRCA1(mut) carriers.

Steroidal contraceptives: effect on bone fractures in women

BACKGROUND

Steroidal contraceptive use has been associated with changes in bone mineral density in women. Whether such changes increase the risk of fractures later in life is not clear. However, osteoporosis is a major public health concern. Age-related decline in bone mass increases the risk of fracture, especially of the spine, hip, and wrist. Concern about bone health influences the recommendation and use of these effective contraceptives globally.

OBJECTIVES

To evaluate the effect of using hormonal contraceptives before menopause on the risk of fracture in women

SEARCH STRATEGY

We searched MEDLINE, POPLINE, CENTRAL, EMBASE, and LILACS for studies of fracture or bone health and hormonal contraceptives. We wrote to investigators to find additional trials.

SELECTION CRITERIA

Randomized controlled trials were considered if they examined fractures, bone mineral density (BMD), or bone turnover in women with hormonal contraceptive use prior to menopause. Studies were excluded if hormones were provided for treatment of a specific condition rather than for contraception. Interventions could include comparisons of a hormonal contraceptive with a placebo or with another hormonal contraceptive. Interventions could also include the provision of a supplement versus a placebo.

DATA COLLECTION AND ANALYSIS

We assessed for inclusion all titles and abstracts identified through the literature searches with no language limitation. The weighted mean difference (WMD) was computed with 95% confidence interval (CI) using a fixed-effect model.

MAIN RESULTS

No trial had fracture as an outcome. Combination contraceptives did not appear to affect bone health. Of progestin-only methods, depot medroxyprogesterone acetate (DMPA) was associated with decreased bone mineral density, while results were inconsistent for implants. The two placebo-controlled trials showed BMD increases for DMPA plus estrogen supplement and decreases for DMPA plus placebo.

AUTHORS' CONCLUSIONS

Whether steroidal contraceptives influence fracture risk cannot be determined from existing information. Due to different interventions, no trials could be combined for meta-analysis. Many trials had small numbers of participants and some had large losses to follow up. Health care providers and women should consider the costs and benefits of these effective contraceptives. For example, injectable contraceptives and implants provide effective, long-term birth control yet do not involve a daily regimen. Progestin-only contraceptives are considered appropriate for women who should avoid estrogen due to medical conditions.

Prevention of cancers of the breast, endometrium and ovary

A central epidemiological feature of cancers of the breast, endometrium and ovary is the sharp slowing down in their rate of increase with age around the time of menopause. The incidence of these tumors by the age of 70 years would be between fourfold and eightfold increased if the rapid increase with age seen in young women continued into old age. These phenomena can be explained by the different effects of ovarian hormones on cell division rates in the relevant tissues. Models of these effects provide a plausible explanation of most of the known epidemiology of each of the cancers, including the increase in breast cancer risk from menopausal estrogen-progestin therapy. Some recent epidemiological findings in endometrial and ovarian cancer suggest new avenues for possible chemoprevention of these cancers.

Hormone replacement therapy and breast cancer

There is considerable evidence that the risk of breast cancer is related to ovarian function. However, the effect of postmenopausal hormone replacement therapy (HRT) on breast cancer risk continues to be debated in the absence of data from randomised controlled trials. Observational studies suggest that HRT probably promotes the growth of pre-existing breast cancers rather than initiating malignant transformation of breast epithelial cells but without exerting an obviously detrimental effect on disease-specific mortality. The controversy surrounding HRT and breast cancer has become additionally more complex as a result of the dilemma faced by clinicians advising women rendered oestrogen-deficient by breast cancer therapy. Whilst HRT is currently contra-indicated due to theoretical concerns that it will promote disease recurrence, its increasing, ad hoc prescription to symptomatic breast cancer patients has not been associated with an increase in disease recurrence. Large-scale randomised trials of HRT in healthy women and breast cancer survivors are now ongoing but it will be some years before useful clinical information becomes available. Until then, the limitations and biases implicit as a result of the design of observational studies must be borne in mind when interpreting such studies.

Future possibilities in the prevention of breast cancer: luteinizing hormone-releasing hormone agonists

The cyclic production of estrogen and progesterone by the premenopausal ovary accounts for the steep rise in breast cancer risk in premenopausal women. These hormones are breast cell mitogens. By reducing exposure to these ovarian hormones, agonists of luteinizing hormone-releasing hormone (LHRH) given to suppress ovarian function may prove useful in cancer prevention. To prevent deleterious effects of hypoestrogenemia, the addition of low-dose hormone replacement to the LHRH agonist appears necessary. Pilot data with such an approach indicates it is feasible and reduces mammographic densities.

Prevention of rat mammary carcinoma utilizing leuprolide as an equivalent to oophorectomy

A clinical trial is currently under way to examine the effectiveness of leuprolide as a breast cancer chemopreventive agent and contraceptive. This trial, as well as similar proposed studies, is based on the assumption that leuprolide is as effective as surgical castration in preventing the onset of mammary tumors; however, this has not been well documented in the DMBA animal model. We directly compared leuprolide and oophorectomy in this model and examined a combined therapy of leuprolide/bromocriptine. Twenty-seven day old female Sprague-Dawley rats were randomly allocated into one of eight groups. All rats received a 20-mg dose of DMBA at the age of 55 days. Group 1 (n = 10), no treatment; Group 2 (n = 9), leuprolide (100 microg/kg/day) for eight weeks beginning four weeks prior to DMBA; Group 3 (n = 10), oophorectomy four weeks prior to DMBA with replacement estrogen beginning four weeks following DMBA. Estrogen replacement was achieved with a 0.05-mg estradiol tablet releasing 0.833 microg/day over a 60-day period. Group 4 (n = 10), leuprolide (100 microg/kg/day) initiated two weeks prior to DMBA and continuing for two weeks following DMBA; Group 5 (n = 9), oophorectomy two weeks prior to DMBA with 0.05 mg of estradiol in depot form, releasing 0.833 microg/day, beginning four weeks following DMBA and continuing until week 16 of the study; Group 6 (n = 10), leuprolide (100 microg/kg/day) beginning two weeks prior to DMBA and continuing for the duration of the experiment; Group 7 (n = 10), leuprolide (100 microg/kg/day) for eight weeks beginning two weeks prior to DMBA; Group 8 (n = 9), leuprolide (100 microg/kg/day) and bromocriptine (83 microg/day) for eight weeks beginning two weeks prior to DMBA. At nineteen weeks (15 weeks post DMBA), animals were sacrificed and autopsies performed. One hundred percent of untreated animals developed tumors. No animals undergoing oophorectomy four weeks prior to DMBA or receiving leuprolide four weeks prior to and simultaneously with DMBA developed tumors. In animals pretreated two weeks prior to DMBA with leuprolide or oophorectomy, each group had one animal with tumor development. No tumors developed in the animals receiving ongoing injections of leuprolide. However, one tumor developed in those receiving leuprolide for the first eight weeks beginning two weeks prior to DMBA administration. One animal receiving both leuprolide and bromocriptine developed one tumor. We conclude that chemical oophorectomy (with leuprolide) is as effective as surgical oophorectomy in inhibiting DMBA induced carcinogenesis.

Prevention of DMBA-induced rat mammary carcinomas comparing leuprolide, oophorectomy, and tamoxifen

Leuprolide, a gonadotropin releasing hormone agonist, is currently being evaluated in a pilot study of premenopausal women for the prevention of breast cancer. However, little data is available regarding the efficacy of leuprolide in experimental animal models of carcinoma when administered prior to the carcinogen. In the present study the capacity of leuprolide to prevent tumor development was evaluated by comparing its pretreatment effects in the DMBA-induced rat mammary carcinoma model to pretreatment with tamoxifen and oophorectomy. Fifty-five day old, female Sprague-Dawley rats were randomly allocated to one of four groups: 1) no treatment; 2) oophorectomy two weeks prior to DMBA; 3) leuprolide, 40 microg/kg/day; and 4) tamoxifen, 10 mg/kg/week. All animals received four 5 mg doses of DMBA for a total dose of 20 mg. Leuprolide and tamoxifen treatments began two weeks prior to DMBA and ended one week after DMBA administration. Animals were assessed weekly to determine palpable tumor onset, number, size, and volume. At the conclusion of the study (16 weeks), autopsies were performed and tumor tissue was collected for confirmation of malignancy. Seventy-eight percent of the untreated rats developed tumors. No tumors developed in the oophorectomy group, while the number of rats with tumors was significantly reduced (p<0.05) with both leuprolide (30%) and tamoxifen (21.9%) compared to controls (77.8%). There were no significant differences in the tumor number for each tumor-bearing rat or in tumor volume between treated and control groups. Using our dosage regimen, 'chemical oophorectomy' with leuprolide was not as effective as surgical oophorectomy in the prevention of chemical carcinogenesis by DMBA but was comparable to the results obtained with tamoxifen.

Assessment of preference for breast cancer chemoprevention in Japanese young women

Pills containing estrogen and progesterone or gonadotropin releasing hormone agonist have been considered valuable to prevent breast cancer. This study assessed preference for the combination-type pill for preventing breast cancer, to evaluate the hypothetical preventive effect of this agent among young Japanese women. The standard gamble method was applied. Fifty-five college students and 44 nursing school students aged between 18 and 41 years were asked to decide the probability of being affected by breast cancer at which they would start to take this agent. Preference score was calculated by subtracting the probability given by each respondent from 1, which corresponds to the value (utility) she allotted to the agent. The means of preference score were 0.58, 0.48, 0.37, and 0.27 for 100, 75, 50, and 25% of efficacy levels of the agent, respectively. Preference score was significantly lower in nursing school students and those whose knowledge about hormones were relatively high. Score of Health Locus of Control (HLC) was nonsignificantly negatively correlated with preference score at any efficacy level. HLC score was significantly higher among those who refused the agent with 50 and 25% efficacy levels at 100% level of breast cancer risk. The data suggest that perceived risk of this agent was not negligibly small in this population and school status, knowledge about hormones, and beliefs about health would affect preference for the agent. Understanding of preference for chemopreventive agents for breast cancer, especially those containing hormones, is important to assess their potential as future preventive agents and is helpful when planning a strategy of chemoprevention.

Magnesium deficiency: possible role in osteoporosis associated with gluten-sensitive enteropathy

Osteoporosis and magnesium (Mg) deficiency often occur in malabsorption syndromes such as gluten-sensitive enteropathy (GSE). Mg deficiency is known to impair parathyroid hormone (PTH) secretion and action in humans and will result in osteopenia and increased skeletal fragility in animal models. We hypothesize that Mg depletion may contribute to the osteoporosis associated with malabsorption. It was our objective to determine Mg status and bone mass in GSE patients who were clinically asymptomatic and on a stable gluten-free diet, as well as their response to Mg therapy. Twenty-three patients with biopsy-proven GSE on a gluten-free diet were assessed for Mg deficiency by determination of the serum Mg, red blood cell (RBC) and lymphocyte free Mg2+, and total lymphocyte Mg. Fourteen subjects completed a 3-month treatment period in which they were given 504-576 mg MgCl2 or Mg lactate daily. Serum PTH, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and osteocalcin were measured at baseline and monthly thereafter. Eight patients who had documented Mg depletion (RBC Mg2+ < 150 microM) underwent bone density measurements of the lumbar spine and proximal femur, and 5 of these patients were followed for 2 years on Mg therapy. The mean serum Mg, calcium, phosphorus and alkaline phosphatase concentrations were in the normal range. Most serum calcium values fell below mean normal and the baseline serum PTH was high normal or slightly elevated in 7 of the 14 subjects who completed the 3-month treatment period. No correlation with the serum calcium was noted, however. Mean serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and osteocalcin concentrations were also normal. Despite only 1 patient having hypomagnesemia, the RBC Mg2+ (153 +/- 6.2 microM; mean +/- SEM) and lymphocyte Mg2+ (182 +/- 5.5 microM) were significantly lower than normal (202 +/- 6.0 microM, p < 0.001, and 198 +/- 6.8 microM, p < 0.05, respectively). Bone densitometry revealed that 4 of 8 patients had osteoporosis of the lumbar spine and 5 of 8 had osteoporosis of the proximal femur (T-scores < or = -2.5). Mg therapy resulted in a significant rise in the mean serum PTH concentration from 44.6 +/- 3.6 pg/ml to 55.9 +/- 5.6 pg/ml (p < 0.05). In the 5 patients given Mg supplements for 2 years, a significant increased in bone mineral density was observed in the femoral neck and total proximal femur. This increase in bone mineral density correlated positively with a rise in RBC Mg2+. This study demonstrates that GSE patients have reduction in intracellular free Mg2+, despite being clinically asymptomatic on a gluten-free diet. Bone mass also appears to be reduced. Mg therapy resulted in a rise in PTH, suggesting that the intracellular Mg deficit was impairing PTH secretion in these patients. The increase in bone density in response to Mg therapy suggests that Mg depletion may be one factor contributing to osteoporosis in GSE.

The endocrine prevention of breast cancer

A clear explanation for the high incidence of breast cancer in modern women is now possible. The risk of breast cancer rises steeply from menarche until menopause. Associated with the reproductive process, the ovary, including the corpus luteum, produces substantial amounts of estrogen and progesterone, both of which induce growth of the breast epithelium. This sex-steroid-driven breast epithelial cell proliferation increases the risk of carcinogenesis by accelerating the occurrence of somatic genetic errors. Postmenopausally, as there is little cell proliferation, the breast epithelium is more "resistant" to mutagenic effects, and breast cancer risk rises at a low rate. Unfortunately, the genetic errors accumulated during the premenopausal period are not lost following menopause, and breast cancer risk remains high. Sex-steroid antagonists, such as tamoxifen, may reduce breast cancer incidence both by blocking breast epithelial cell proliferation and by direct antitumor effects on clinically occult breast cancers. The rationale for a contraceptive designed to reduce breast cell proliferation by decreasing premenopausal sex-steroid exposure is presented.

Breast cancer prevention through modulation of endogenous hormones

The use of exogenous sex-steroids for hormonal contraception is important to the way of life of many modern women. The widespread use of hormonal contraceptives represents a unique opportunity to have a substantial positive impact on women's health. The observation that users of oral combination type contraceptives have a reduced risk of ovarian cancer should encourage the extension of contraceptive development to address the most important malignancy facing modern women, breast cancer. Epidemiological evidence strongly suggests that both estrogens and progestogens contribute to breast cancer risk, and account for the steep rise in risk seen during the premenopausal years. Studies of normal breast epithelial cell proliferation confirm that progestogens are breast mitogens, and explain why current contraceptives, which are progestogen dominant, do not prevent breast cancer. A long-acting depot contraceptive can be developed which releases: 1) an agonist of gonadotropin releasing hormone to suppress ovarian function; and 2) sex-steroids at doses below those in current contraceptives, and below those associated with ovulation. Such a contraceptive should provide substantial life-time protection against both breast and ovarian cancer, and would retain many of the other health benefits of current contraceptives.

The chemoprevention of breast cancer by reducing sex steroid exposure: perspectives from epidemiology

Mitogenesis is a major driving force in neoplastic development. Blocking the effect of breast cell mitogens by reducing the actual exposure of the breast to these mitogens is an obvious strategy for breast cancer prevention. The ovarian hormones, estrogens and progesterone, are major effective (direct or indirect) breast cell mitogens. A woman's exposure to ovarian estrogens and progesterone is drastically reduced by the use of combination-type oral contraceptives (COCs), but the synthetic estrogen and progestogen in the COCs effectively replace ovarian estrogens and progesterone, so that breast cell exposure to these hormones is not decreased. Doses of estrogen and progestogen in modern COCs are close to the minimum attainable while still retaining both contraceptive efficacy and ovarian suppression (so that endogenous estrogen and progesterone do not add to the dose of estrogen and progestogen from the COC). Considerably lower effective breast cell exposure to estrogen and progestogen can, however, be achieved by using a gonadotropin-releasing hormone agonist (GnRHA) to suppress ovarian function and compensate for the resulting hypoestrogenemia with low-dose hormone replacement therapy. Compared to modern COCs, estrogen exposure can be reduced by approximately 60%, and progestogen dose by more than 80%. Such a contraceptive is predicted to reduce lifetime breast cancer risk by more than 50% if used for 10 years. The possibility that a practical contraceptive could achieve such a major benefit is shown by the dramatic decline in the incidence of both ovarian and endometrial cancer in young women in the U.S. over the last 3 decades--a direct result of COC use.