Treatment of endometriosis with a delayed release preparation of the agonist D-Trp6-luteinizing hormone-releasing hormone: long-term follow-up in a series of 50 patients

Induction of follicular growth and ovulation with urinary and recombinant gonadotrophins

Gonadotrophins have been used since the 1930s. By the 1990s, a pure biological extract of FSH was obtained. The increase in the demand for new assisted reproduction techniques led to the creation of recombinant FSH, 99% pure and highly consistent between batches, with no LH activity, and a high specific activity. In gonadotrophin protocols, follicular growth can be monitored with regular ultrasounds and/or hormonal testing, mainly oestradiol in the follicular phase. In assisted reproduction the adoption of ovulation induction strategies with GnRH analogues, control the endogenous secretion of LH, avoiding cancellations due to an early LH surge, and premature ovulation. Depending on the moment when pituitary suppression starts, there are short, ultra-short and long protocols The use of long protocols not only increases pregnancies and live births, it also allows an easier programming and simplifies IVF treatments. Ovarian stimulation entails some risks such as ovarian hyperstimulation syndrome and multiple pregnancies that can be avoided in many cases with an accurate prediction and an active prevention.

Prevention of bone loss and hypoestrogenic symptoms by estrogen and interrupted progestogen add-back in long-term GnRH-agonist down-regulated patients with endometriosis and premenstrual syndrome

OBJECTIVE

To examine the utility of a low-dose estrogen and pulsed progestogen hormone replacement therapy (HRT) regimen for add-back during long-term gonadotropin-releasing hormone-agonist (GnRH-agonist) therapy.

DESIGN

A pilot clinical trial conducted at a tertiary referral, academic, reproductive sciences center. The study included 15 patients with endometriosis and 5 patients with severe premenstrual syndrome (PMS). Patients with endometriosis received leuprolide acetate depot 3.75 mg IM monthly until their symptoms had resolved (2-3 months), at which time HRT was initiated along with the GnRH-agonist. Patients with severe PMS received the same treatment with the addition of HRT after 1 month. The HRT regimen consisted of 1 mg oral micronized estradiol daily and 0.35 mg norethindrone daily for 2 days alternating with 2 days without norethindrone. The main outcome measure included bone density assessment in the lumbar spine and femoral neck by dual-energy x-ray absorptiometry at 6- to 12-month intervals. The mean follow-up duration +/- SD while on GnRH-agonist treatment was 31.2 +/- 17 months (for endometriosis patients) and 37.7 +/- 8.4 months (for patients with severe PMS).

RESULTS

Bone mineral density was stable after initiation of HRT for the entire follow-up period. No patient had return of pelvic pain or resumption of mood swings after HRT add-back. After the first 3 months of HRT, all women remained amenorrheic.

CONCLUSIONS

Long-term GnRH-agonist down-regulation is safe and effective when combined with HRT add-back. Furthermore, on the basis of this small study, the low-dose pulsed progestogen, continuous estrogen HRT regimen seems to be safe for use as add-back therapy in terms of bone health.

Medical and surgical therapies for pain associated with endometriosis

Endometriosis is a common condition for which a number of treatments have been proposed. Medical treatments are based on the hormonal responsiveness of endometriosis implants. These therapies include progestins (with or without estrogens), androgens, and gonadotropin-releasing hormone (GnRH) analogs. Surgical treatments may include hysterectomy with oophorectomy or organ-sparing surgery involving ablation or resection of visible lesions of endometriosis and restoration of pelvic anatomy. There are no studies that directly compare the effectiveness or adverse effects of medical therapy and surgical therapy. Studies on medical therapy compare different treatments with placebo or with other active treatments. Hormone-based therapies for endometriosis show 80%-100% effectiveness in relief of pelvic pain over a 6-month course of therapy. Serious adverse outcomes after medical therapy are unusual. Studies on surgical therapy are largely anecdotal, with noncomparative reports on a variety of surgical methods. A few comparative surgical studies have been reported. Because of the noncomparative nature of many of the surgical studies, the use of combinations of surgical procedures and techniques in the reported studies, and the reporting of results from surgeons with an unusually high level of technical skill, the gynecological practitioner has little basis in the literature for assessing the optimum surgical approach. Surgical complications are believed to be underreported and may be related to how aggressive a surgical procedure is undertaken.

Medical management of endometriosis and infertility

OBJECTIVE

To review the literature on the use of medical management of endometriosis and infertility.

DESIGN

Literature review.

RESULT(S)

Endometriosis is a common finding in women with infertility, but the mechanism by which it renders a woman infertile remains unclear. Despite many years of controversy and debate, there remains a strong bias against medical treatment for endometriosis-associated infertility. A review of the current literature suggests that medical management of endometriosis may be effective in selected patients and in certain settings, including patients undergoing IVF.

CONCLUSION(S)

A closer look at the question of medical management of endometriosis reveals that much remains to be learned before a final decision can be made about the use of medical therapies, such as GnRH agonists, for endometriosis and associated infertility.

Psychoneuroendocrinology of depression. Hypothalamic-pituitary-gonadal axis

Women are more susceptible than men to depression, particularly during periods of rapid fluctuation of gonadal hormones, such as premenstrually, postpartum, and during the climacteric. This review summarizes the evidence for the association of depression with abnormalities in reproductive hormones. Although there are similarities in stress hormones changes between depressed women and women with stress-related amenorrhea, no abnormalities in LH activity have been documented in depression. Similarly no abnormalities in LH, estradiol, or progesterone have been documented in premenstrual syndrome (PMS), although complete elimination of monthly cycling with leuprolide improves mood. Some studies have suggested beneficial effects of estrogen on mood in postmenopausal women but as yet there have been no adequately controlled studies of estrogen treatment of either premenopausal or postmenopausal women.

Long-acting triptorelin for the treatment of endometriosis

OBJECTIVE

To evaluate the efficacy and adverse effects of monthly triptorelin injection for the treatment of endometriosis.

METHODS

A multicenter clinical trial including 45 women with endometriosis, treated with triptorelin 3.75 mg i.m. every 4 weeks in six consecutive doses. The main outcome measures were symptom relief, reduction according to revised American Fertility Society (rAFS) scores, reduction in size of ovarian endometrioma, effects on hormone and lipid profiles, changes in bone mineral density (BMD), adverse effects, and return of menstruation. Data were analyzed using repeated measures analysis of variance and paired t-tests.

RESULTS

Pain-related symptoms decreased in all cases after 8 weeks of treatment. Laparoscopic assessment revealed a reduction in rAFS scores in 21 out of 25 cases (mean pretreatment scores 43.44 +/- 5.75 vs. post-treatment scores 22.30 +/- 3.40, P < 0.001). The size of ovarian endometrioma decreased in eight of nine women but none disappeared. Serum luteinizing hormone, follicle-stimulating hormone and estradiol levels were effectively suppressed during treatment. A slight increase in cholesterol and triglyceride levels was observed but all values were within normal limits. After 24 weeks of treatment there was a slight decrease in BMD of total body, lumbar vertebrae and femoral neck but not radius. The main adverse effects included hot flushes, night sweating, vaginal dryness, headache, dizziness and nausea Menstruation returned 83.76 +/- 2.91 days after the last injection of triptorelin.

CONCLUSION

Long-acting triptorelin is efficacious in the treatment of endometriosis and has tolerable side effects.

Multiple polypoid endometriosis--a rare complication following withdrawal of gonadotrophin releasing hormone (GnRH) agonist for severe endometriosis: a case report

A 30-year old female who initially had typical endometriosis treated according to a standard regimen later developed numerous highly vascular endometrial polyps on the vagina, cervix, ureter, serosal surfaces of the uterus, pouch of Douglas (POD) and other areas of pelvic peritoneum as well as the endometrium 8 months after withdrawal of treatment with Zoladex gonadotrophin releasing hormone (GnRH) agonist used for treatment of this disease. We postulate that these polyps developed as a rebound phenomenon upon withdrawal of Zoladex. We believe this is the first report of this complication following use of GnRH analogue.

The effect of add-back treatment with tibolone (Livial) on patients treated with the gonadotropin-releasing hormone agonist triptorelin (Decapeptyl)

OBJECTIVE

To assess whether tibolone can prevent the bone loss and symptomatic side effects normally associated with GnRH agonist (GnRH-a) use and whether tibolone modifies the effect of GnRH-a on endometriosis.

DESIGN

Prospective, double-blind, placebo-controlled, group comparative study.

SETTING

Gynecological research unit in a London teaching hospital.

PATIENTS

Twenty-nine patients with endometriosis and two with fibroids.

INTERVENTIONS

Six months of treatment with 3.75 mg/mo IM triptorelin combined with daily tablets of either placebo or 2.5 mg tibolone.

MAIN OUTCOME MEASURES

Daily symptom diary for hot flushes and bleeding episodes, laparoscopic scoring of endometriosis, endocrine and biochemical changes, and bone mineral density scans.

RESULTS

Lumbar spine bone mineral density decreased significantly from baseline in the placebo group (-5.1%) but not in the tibolone group (-1.1%). The frequency of hot flushes and sweating episodes was reduced significantly by tibolone. There was no difference between the two treatment groups with regard to the endometriosis scores.

CONCLUSIONS

The addition of tibolone to GnRH-a treatment reduces the bone loss and vasomotor symptoms that normally occur with GnRH-a, thus making long-term treatment with GnRH-a safer and more acceptable. It does not negate the therapeutic effect of GnRH-a on endometriosis.

Pain recurrence: a quality of life issue in endometriosis

Studies reveal endometriosis to be present in 38-51% of women undergoing laparoscopy for chronic pelvic pain. Symptoms attributable to endometriosis include dysmenorrhea, dyspareunia, generalized pelvic pain, dyschezia, and radiation of pain to the back or leg. Psychological factors may also contribute to a more intense pain experience. Medical therapy provides symptom relief in 72-93% of patients, although recurrence is common following treatment discontinuation. Surgical therapy has had varying results for long-term pain relief; adequacy of the initial surgical treatment appears to be a critical factor. Important adjunctive measures include presacral neurectomy and excisional techniques to remove deep, fibrotic, retroperitoneal lesions. The quality of life of women with endometriosis will improve with greater focus on achieving the long-term relief of pelvic pain. Limitation of pain recurrence would benefit the patient greatly, by providing symptom relief and preventing the cycle of its probably adverse effects on physical activity, work productivity, sexual fulfilment, and mood.

Evaluation of the in vitro and in vivo activity of the L-, D,L- and D-Cit6 forms of the LH-RH antagonist Cetrorelix (SB-75)

The objective of this study was to examine the in vivo and in vitro gonadotropin-inhibiting potencies, edematogenic activities and the receptor binding affinities of the D-Cit6, D,L-Cit6 and L-Cit6 forms of the LH-RH antagonist Cetrorelix (SB-75) [Ac-D-Nal(2)1,D-Phe(4Cl)2,D-Pal(3)3,D-Cit6,D-Ala10]LH- RH. In order to demonstrate the suppressive effects of two different diastereomers of SB-75 and their racemic mixture on LH and FSH release, [D-Cit6] SB-75 was injected subcutaneously in doses of 2.5 and 10 micrograms/rat, [D,L-Cit6]-SB-75 in doses of 5 and 20 micrograms/rat and [L-Cit6] SB-75 in doses of 12.5 and 50 micrograms/rat to castrated male rats. Two hours after administration, there was no difference in LH levels between rats injected with the L-form and control animals, indicating a low activity and/or a rapid enzymatic degradation of this peptide. The (1:1) diastereomeric mixture was only about half as potent in suppression of LH release compared to [D-Cit6] SB-75. Serum FSH levels were suppressed significantly (p < 0.01) for more than 48 h after the administration of 10 micrograms [D-Cit6] SB-75 and 20 micrograms of [D,L-Cit6] SB-75, respectively. [D-Cit6] SB-75 administered at a dose of 2 micrograms/rat induced 100% inhibition of ovulation, while 4 micrograms/rat of the D,L-Cit6 peptide were necessary to produce the same effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Deeply infiltrating endometriosis is a disease whereas mild endometriosis could be considered a non-disease

Deeply infiltrating endometriosis can be defined as endometriosis infiltrating deeper than 5 mm under the peritoneal surface. Type I is a conical lesion suggested to be caused by infiltration; type II is mainly caused by retraction of the bowel over the lesion; type III is the most severe lesion suggested to be caused by adenomyosis externa. Severe cases are clinically apparent by nodularities in the pouch of Douglas, whereas mild and subtle forms of deep endometriosis are easily missed. Clinical examination during menstruation and scrutiny at laparoscopy for indurations, followed, preferably, by CO2-laser-excision are the key features for diagnosis and treatment. It is important to realize that depth of infiltration and lateral spread cannot be evaluated by laparoscopic inspection but only during excision, that CA125 concentration but not ultrasound or nuclear magnetic resonance can be helpful in the diagnosis, and that in the most severe cases medical pretreatment is advocated. Results of excision, as evaluated by disappearance of pain in some 80% of women, by a cumulative pregnancy of some 70% and a low recurrence rate, are excellent. The peritoneal fluid is thought to play a key role in the physiopathology of deep endometriosis which is considered to be endometriosis which has escaped from the influence of the peritoneal fluid. This concept is clinically important for the medical treatment of endometriosis, which is suggested to shrink deep lesions and to bring them back under peritoneal fluid control. A model of endometriosis is proposed and discussed. Subtle lesions are considered a natural condition occurring intermittently in all women, whereas we question whether mild endometriosis is a disease. In some women endometriosis has an aggressive behavior and develops into cystic ovarian endometriosis or into deeply infiltrating endometriosis. In this model subtle and mild forms would be called "endometriosis," whereas deep and cystic ovarian forms could be called "endometriotic disease." It is stressed that deep and cystic ovarian endometriosis are two distinct entities, which is important for our understanding of endometriosis, for classification and for treatment of endometriosis.

Impact of different GnRH analogs in benign gynecological disorders related to their chemical structure, delivery systems and dose

This review addresses the question of whether the different gonadotropin releasing hormone (GnRH) agonists in clinical use might have different impacts, related to their chemical structure, delivery system and dose. Impact was investigated in benign gynecological disorders, i.e. endometriosis and leiomyoma. Arguments are presented indicating that a difference in impact of different analogs can be expected. All currently used intranasal, daily subcutaneous and depot preparations finally give rise to low levels of serum estradiol. The number of days before the first ovulatory menstruation after discontinuation of GnRH agonist treatment is remarkably constant. Four weeks after the last impact of the agonist, there is resumption of follicle growth. This phenomenon is independent of chemical structure, delivery system and dose. One should realize, however, that it generally takes about 30 days before the impact of a depot preparation disappears. Consequently, the impact of a depot preparation lasts 4 weeks longer than that of an otherwise applied agonist. Thus resumption of pituitary activity after discontinuation of a depot formulation takes 4 weeks longer than after discontinuation of non-depot formulations. All agonists have an impressive effect on endometriosis, independent of their chemical structure and delivery system. However, there are no studies comparing different agonists with the same delivery system in comparable endometriosis groups. Similarly, all agonists considerably reduce myoma volume, independently of their chemical structure and delivery system.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Depot leuprolide acetate versus danazol in the treatment of women with symptomatic endometriosis: a multicenter, double-blind randomized clinical trial. II. Assessment of safety. The Lupron Endometriosis Study Group

OBJECTIVES

This is the first multicenter, double-blind randomized clinical trial that compares a depot gonadotropin-releasing hormone agonist with danazol in the treatment of endometriosis. Efficacy results have been previously reported; this report focuses on safety data.

STUDY DESIGN

A total of 270 patients from 22 centers were randomly selected to receive either leuprolide acetate depot (3.75 mg injected monthly) or danazol (800 mg administered orally daily). Safety outcomes included adverse effects, clinical laboratory changes, and bone mineral density changes.

RESULTS

Most patients receiving either drug reported side effects, most of which were related to the hypoestrogenism of leuprolide (e.g., vasodilatation) and relative hyperandrogenism of danazol (e.g., weight gain). Similarly small numbers of patients dropped out of the two treatment groups because of the side effects encountered. Leuprolide depot caused a greater decrease in bone density; preliminary data suggest a return to baseline on cessation of the drug. Danazol was associated with alteration of serum lipids, specifically a significant decrease in high-density lipoprotein.

CONCLUSIONS

Although side effects were commonly reported in both groups, the drugs were similarly safe in terms of the absence of serious complications and the results of cessation of therapy. Side effects were largely reversible on discontinuation of medication. More longitudinal data are necessary before the possibility of long-term risks can be excluded, especially as they pertain to bone mineral density and lipids.

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

Combination oral contraceptive (COC) users have reduced risks of ovarian and endometrial cancer, but COCs have not reduced breast cancer risk. We have previously argued that a hormonal contraceptive with substantially lower doses of sex-steroids should reduce breast cancer risk by decreasing the breast epithelial cell proliferation below usual premenopausal levels. We report here the preliminary results of a pilot trial with such a prototype contraceptive consisting of an agonist of gonadotropin releasing hormone (GnRHA) administered with low doses of an oral estrogen (0.625 mg of conjugated estrogen, CE, for 6 days every week) and intermittent oral progestogen (10 mg of medroxyprogesterone acetate, MPA, for 13 days every 4 months). Eighteen subjects at five-fold or greater increased breast cancer risk were entered and randomized -12 to the contraceptive arm and 6 to a control arm. The principal endpoints included tolerance of the regimen, vaginal bleeding patterns, and the regimen's effect on the endometrium, bone metabolism, and lipids. A symptom questionnaire was used to assess tolerance; the contraceptive subjects had fewer symptoms following initiation of the regimen. This results from the elimination of symptoms associated with the luteal phase of the menstrual cycle, commonly referred to collectively as premenstrual syndrome, PMS. The few occurrences of hot flushes or vaginal dryness that did occur were eliminated by small increases in estrogen dose (0.9 mg CE). Scheduled vaginal bleeding occurred associated with most periods of progestogen administration. Unscheduled bleeding or spotting was infrequent and decreased with time on the regimen. A beneficial rise in high-density lipoprotein cholesterol was evident in the contraceptive subjects. Despite the use of an estrogen dose which is known to prevent loss of bone mineral density in normal postmenopausal women, an annualized loss of 1.9% was seen in contraceptive subjects. It is hypothesized that this is secondary to inhibition of ovarian androgen production by the GnRHA, which may additionally account for changes in libido occasionally reported with GnRHA. The study continues with the addition of a small dose of androgen to replace that lost by the action of the GnRHA.

Evaluation of biological activities of new LH-RH antagonists (T-series) in male and female rats

A series of new highly potent LH-RH antagonists (T-series) has been synthesized in our laboratory. Among these analogs, antagonists [Ac-D-Nal(2), D-Phe(4Cl)2, D-Pal(3)3, D-Lys(A2pr(Car)2)6, D-Ala10]LH-RH (T-140); [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Lys(A2pr(Ac)2)6, D-Ala10]LH-RH (T-148); [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Lys(A2pr(For)2)6, D-Ala10]LH-RH (T-151) and [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Lys(A2bu(For)2)6, D-Ala10]LH-RH (T-159) were the most powerful. Antagonists T-140, T-148 and T-151 produced a complete blockade of ovulation in normal cycling rats at a dose of 1.5 micrograms/rat and antagonist T-159 at a dose of only 0.75 micrograms/rat. The inhibitory effects of compounds T-148, T-151 and T-159 on gonadotropin and sex steroid secretion were investigated in male and female rats. To determine their effect on LH levels in castrated male and ovariectomized female rats, T-148, T-151 and T-159 were injected subcutaneously in doses of 0.625 and 2.5 micrograms/rat. Blood samples were taken at different intervals for 48 h. All three compounds at either dose caused a significant (P < 0.01) decrease in LH levels for more than 6 h. Significant (P < 0.01) inhibition of LH lasted for more than 24 h following a dose of 2.5 micrograms sc of all 3 antagonists in both male and female rats. Serum FSH levels were also suppressed significantly for more than 48 h in castrated male rats by all three antagonists at a dose of 5 micrograms/rat sc.(ABSTRACT TRUNCATED AT 250 WORDS)

Depot leuprolide versus danazol in treatment of women with symptomatic endometriosis. I. Efficacy results

OBJECTIVE

We aimed to assess the efficacy of depot leuprolide versus danazol in the treatment of endometriosis.

STUDY DESIGN

A double-blind randomized trial of 270 patients from 22 centers compared the pretreatment and posttreatment laparoscopic extent of endometriosis. Pretreatment and posttreatment endometriosis symptoms and signs were assessed with standardized methods.

RESULTS

When compared with danazol, leuprolide depot caused a more rapid and profound suppression of estradiol. Leuprolide depot and danazol were similarly efficacious in decreasing the extent of endometriosis, as well as the pain and tenderness associated with endometriosis.

CONCLUSION

Depot leuprolide is an effective alternative to danazol in decreasing the extent of endometriosis and endometriosis-related pain.

Treatment of experimental DMBA induced mammary carcinoma with Cetrorelix (SB-75): a potent antagonist of luteinizing hormone-releasing hormone

Cetrorelix, (Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10)-LHRH (SB-75) is a new highly potent antagonist of LH-RH. In the model of DMBA-induced mammary carcinoma, this antagonist was very effective in reducing tumor mass. A rapid decrease in tumor weights to levels below 0.1 g total tumor mass was achieved with 300 micrograms/kg given sc. daily for 14 days. The weights of uteri and ovaries were reduced to about 40-50% of control values. In all treated rats the estrus cycle was interrupted and the animals remained in a state of anestrus. Microscopically, the effects of Cetrorelix on the tumors were characterized by a loss of mitotic activity, marked regression with apoptosis, an increase of stroma and differentiation towards a normal mammary architecture. On the basis of a dose-response curve, a dose of 100 micrograms/kg/d of Cetrorelix was determined as sufficient for a full antitumor response. Large DMBA-tumors with total tumor mass of about 6 g could also be treated very effectively with a dose of 100 micrograms/kg/d. To achieve a complete tumor regression, the treatment had to last 34 days. After the cessation of treatment with 100 micrograms/kg/d and regrowth of the tumors the animals were treated with the agonist Decapeptyl (Trp6-LHRH) using a dose of 50 micrograms/rat/d for 14 days. Again, the tumors responded well and regressed within 10 days. The treatment with an overlapping dose schedule of Cetrorelix and Decapeptyl showed a continuous antitumor response. A transient stimulation of tumor growth by the LH-RH agonist was not observed under these experimental conditions. In ovariectomized rats bearing DMBA-tumors, treatment with Cetrorelix and estradiol, produced no tumor growth inhibition as compared to estradiol control group, indicating that there is no estrogen nullifying effect of this antagonist on tumor cells in this model. On the basis of these results, Cetrorelix is a highly effective antitumor agent in this breast cancer model, which might also be useful under clinical conditions.

GnRH agonists as contraceptive agents: predicted significantly reduced risk of breast cancer

Gonadotrophin-releasing hormone agonists (GnRHAs) were investigated as contraceptive agents from the late 1970's to the mid-1980's. They were abandoned as they appeared to offer no advantage over conventional combination-type oral contraceptives (COCs). This conclusion appears to be incorrect. We propose here a contraceptive regimen of a depot formulation of a GnRHA plus add-back estrogen and intermittent progestogen. The dose of add-back sex-steroids is substantially less than that in COCs; this reduction in sex-steroids should lead to a major reduction in lifetime breast cancer occurrence.