Gynecologic effects of tamoxifen and the association with endometrial carcinoma

Hormonal Therapies in Cancers

The hormonal therapy for cancer has become a household name and the series of experiments performed leading to the discovery of hormones use in the treatments of breast cancer. The hormones like antiestrogen, aromatase restrictors, antiandrogens, and use of extremely strong luteinizing hormone-releasing hormone agonists to perform a "medical hypophysectomy" because of their ability of causing desensitization in the pituitary gland have proven their value in the treatment of cancers over the last two decades. Millions of women still use hormonal therapy for menopause symptoms. Estrogen plus progestin or estrogen separately utilized as a menopause hormonal therapy throughout the world. Women receiving different premenopausal and postmenopausal hormonal therapies are on higher risk of having ovarian cancer. The risk of ovarian cancer did not increase with the increase of duration of hormonal therapy. Postmenopausal hormone use was found to be inversely related to major colorectal adenomas.

Uterine Malignant Mixed Müllerian Tumors Following Treatment with Selective Estrogen Receptor Modulators in Patients with Breast Cancer: A Report of 13 Cases and Their Clinicopathologic Characteristics

BACKGROUND

Breast cancer treatment with selective estrogen receptor modulators (SERMs) increasesthe incidence of uterine malignant mixed Müllerian tumors (uMMMTs). We examine clinicopathologiccharacteristics and prognosis of SERM-associated uMMMTs (S-uMMMTs) and discusspossible pathogenetic mechanisms.

METHODS

Among 28,104 patients with breast cancer, clinicopathologicfeatures and incidence of uMMMT were compared between patients who underwentSERM treatment and those who did not. Of 92 uMMMT cases that occurred during the same period,incidence, dose, and duration of SERM treatment, as well as overall survival rate, were comparedfor patients with breast cancer who underwent SERM treatment and those who did not (S-uMMMTvs NS-uMMMT) and for patients without breast cancer (de novo-uMMMT). Histopathologicalfindings and immunophenotypes for myogenin, desmin, p53, WT-1, estrogen receptor (ER) α, ERβ,progesterone receptor, and GATA-3 were compared between S-uMMMT and de novo-uMMMT.

RESULTS

The incidence of S-uMMMT was significantly higher than that of NS-uMMMT (6.35-fold).All patients with SERM were postmenopausal and received daily 20-40 mg SERM. CumulativeSERM dose ranged from 21.9 to 73.0 g (mean, 46.0) over 39-192 months (mean, 107). Clinicopathologicfeatures, such as International Federation of Gynecology and Obstetrics stage andoverall survival, were not significantly different between patients with S-uMMMT and NS-uMMMTor between patients with S-uMMMT and de novo-uMMMT. All 11 S-uMMMT cases available forimmunostaining exhibited strong overexpression/null expression of p53 protein and significantlyincreased ERβ expression in carcinomatous and sarcomatous components.

CONCLUSIONS

SERMtherapy seemingly increases risk of S-uMMMT development; however, clinicopathologic featureswere similar in all uMMMTs from different backgrounds. p53 mutation and increased ERβ expressionmight be involved in the etiology of S-uMMMT.

Pomegranate extract demonstrate a selective estrogen receptor modulator profile in human tumor cell lines and in vivo models of estrogen deprivation

Selective estrogen receptor modulators (SERMs) are estrogen receptor (ER) ligands exhibiting tissue-specific agonistic or antagonistic biocharacter and are used in the hormonal therapy for estrogen-dependent breast cancers. Pomegranate fruit has been shown to exert antiproliferative effects on human breast cancer cells in vitro. In this study, we investigated the tissue-specific estrogenic/antiestrogenic activity of methanol extract of pericarp of pomegranate (PME). PME was evaluated for antiproliferative activity at 20-320 μg/ml on human breast (MCF-7, MDA MB-231) endometrial (HEC-1A), cervical (SiHa, HeLa), ovarian (SKOV3) carcinoma and normal breast fibroblast (MCF-10A) cells. Competitive radioactive binding studies were carried out to ascertain whether PME interacts with ER. The reporter gene assay measured the estrogenic/antiestrogenic activity of PME in MCF-7 and MDA MB-231 cells transiently transfected with plasmids coding estrogen response elements with a reporter gene (pG5-ERE-luc) and wild-type ERα (hEG0-ER). PME inhibited the binding of [³H] estradiol to ER and suppressed the growth and proliferation of ER-positive breast cancer cells. PME binds ER and down-regulated the transcription of estrogen-responsive reporter gene transfected into breast cancer cells. The expressions of selected estrogen-responsive genes were down-regulated by PME. Unlike 17β-estradiol [1 mg/kg body weight (BW)] and tamoxifen (10 mg/kg BW), PME (50 and 100 mg/kg BW) did not increase the uterine weight and proliferation in ovariectomized mice and its cardioprotective effects were comparable to that of 17β-estradiol. In conclusion, our findings suggest that PME displays a SERM profile and may have the potential for prevention of estrogen-dependent breast cancers with beneficial effects in other hormone-dependent tissues.

Estrogenic effects of a Kampo formula, Tokishakuyakusan, in parous ovariectomized rats

Female hormone-dependent cancers and other diseases pose a serious health threat for women, and low-risk medicines against such cancers have not yet been discovered. The present study examines the effects of the traditional Chinese herbal mixture, Tokishakuyakusan (TS) and 17beta-estradiol on the uterus of parous ovariectomized rats. Uterine atrophy that causes a reduction in uterine tissue and the uterine cavity area, was induced by ovariectomy, and slightly recovered by the daily oral administration of TS for two weeks (1000 mg/kg body weight). TS restored the decreased plasma estradiol concentration due to ovariectomy. However the yeast two-hybrid assay showed that TS did not bind estrogen receptors alpha and beta and immunohistochemical staining revealed that 17beta-estradiol stimulated the protein expression of estrogen receptor alpha, progesterone receptor, c-fos and c-jun in the uterus, whereas TS did not. These results suggest that TS might be useful for treating menopausal syndromes among women, as well as for patients when hormone replacement therapy (HRT) with estrogen is contraindicated.

Tumorigenic effects of tamoxifen on the female genital tract

Tamoxifen is widely used for endocrine treatment and breast cancer prevention. It acts as both an estrogen antagonist in breast tissue and an estrogen agonist in the female lower genital tract. Tamoxifen causes severe gynecologic side effects, such as endometrial cancer. This review focuses on the effects of prolonged tamoxifen treatment on the human female genital tract and considers its tumorigenicity in the gynecologic organs through clinical data analysis. Tamoxifen is associated with an increased incidence of benign endometrial lesions such as polyps and hyperplasia and a two- to four-fold increased risk of endometrial cancer in postmenopausal patients. Moreover, the incidence of functional ovarian cysts is significantly high in premenopausal tamoxifen users. To prevent tamoxifen from having severe side effects in gynecologic organs, frequent gynecological examination should be performed for both premenopausal and postmenopausal patients with breast cancer who are treated with this drug.

[Uterine abnormalities in non menopausal women who received tamoxifen for breast cancer adjuvant therapy]

OBJECTIVE

To elaborate a strategy of endometrial follow-up for premenopausal women treated with Tamoxifen as adjuvant hormonal treatment of breast cancer.

PATIENTS AND METHODS

Retrospective study of 152 premenopausal patients treated with Tamoxifen in Nantes Comprehensive Cancer Center for a breast cancer from January 2003 to December 2005. Vaginal sonography was used in the follow-up of 70 of them.

RESULTS

Endometrial hypertrophy was found in 26 patients. Sonohysterography and hysteroscopy allowed to find 11 polyps and three hyperplasias in the 19 women who were investigated. In our study, endometrial pathology was found in 20% of premenopausal women treated with Tamoxifen (polyps or hyperplasia). Uterine bleeding was found in half patient of this group.

DISCUSSION AND CONCLUSION

Vaginal sonography monitoring could be proposed to premenopausal women treated with Tamoxifen among whom endometrial pathology is usual.

[Chemotherapy of advanced endometrial carcinoma]

<zakljucak> Pri donosenju odluke o lecenju bolesnice sa karcinomom endometrijuma znacajno je: 1) da li je bolest u odmaklom stadijumu ili je prisutan recidiv tumora, 2) da li je prethodno sprovedena terapija i ako jeste, koji vid terapije (zracenje ili hemioterapija), 3) da li je tumor merljiv ili nemerljiv i 4) o kom se histoloskom tipu tumora radi. Kod pojave recidiva znacajno je da li se on javio u prethodno zracenom polju ili van njega. Treba imati u vidu da je prezivljavanje bolesnica sa odmaklim i recidivirajucim karcinomom endometrijuma oko jedne godine i da su dosadasnji protokoli pokazali manje ili vise izrazenu toksicnost. S tog aspekta, vazno je i da primenjena terapija ne izazove znacajno oboljenje i narusavanje kvaliteta zivota bolesnice. Terapija uznapredovalog, metastatskog i recidivirajuceg karcinoma endometrijuma zahteva individualni pristup u zavisnosti od zivotne dobi i opsteg stanja bolesnice, mesta recidiva i prethodno sprovedene terapije. Pored hemioterapije, terapijske mogucnosti koje su na raspolaganju za sada su palijativna hirurgija i radioterapija, kao i hormonska terapija. .

An alpha-fetoprotein-derived peptide reduces the uterine hyperplasia and increases the antitumour effect of tamoxifen

Tamoxifen (Tam) is effective for the treatment and prevention of breast cancer. However, it has toxic drawbacks and has limited-duration utility because, over time, human tumours become refractory to Tam. Recently, a new nontoxic peptide, alpha-fetoprotein-derived peptide (AFPep) has been proposed for the treatment and prevention of breast cancer. The purpose of this paper is to determine whether combining AFPep with Tam would increase efficacy and reduce toxicity in experimental models of breast cancer. Low doses of AFPep and Tam were more effective in combination than either agent alone against breast cancer growth in cell culture, in tumour-xenografted mice, and in carcinogen-exposed rats. alpha-Fetoprotein-derived peptide interfered with Tam-induced uterine hyperplasia in immature mice, and showed no toxic effects. Unlike Tam, AFPep did not inhibit binding of oestradiol (E(2)) to oestrogen receptor (ER). Thus, these two agents utilise different mechanisms to interfere with ER functionality, yet work cooperatively to reduce breast cancer growth and alleviate Tam's troubling toxicity of uterine hyperplasia and appear to be a rational combination for the treatment of ER-positive breast cancer.

Modeling the effect of tamoxifen chemoprevention on long-term mortality in white women at high risk of breast cancer

Tamoxifen has long been studied as a drug to treat breast cancer and now for its preventive effect. Intermediate results from studies on the preventive effect of tamoxifen vs. placebo endorsed tamoxifen's efficacy after a short follow-up. Effect of tamoxifen on long-term survival was simulated in women at a high risk of breast cancer. The model allows for tamoxifen effect on breast cancer according to estrogen receptor status, endometrial cancer, and pulmonary embolism. A virtual cohort of 200,000 white women was split into two treatment arms (placebo vs. tamoxifen), two age groups (35-49 and 50-74), and followed-up for 20 years. Incidence rates stemmed from the National Surgical Adjuvant Breast and bowel Project-P1, or the chemoprevention trials overview by Cuzick et al., and relative survival probabilities from surveillance, epidemiology, and end results. Six hypotheses of tamoxifen effects and their variations along time were considered. In the National Surgical Adjuvant Breast and Bowel Project-based results, women aged 35-49 took advantage of tamoxifen whatever the follow-up duration and hypothesis, except the one of only side effects remaining 15 years after treatment withdrawal. In the overview-based results, the advantage existed only when effect on pulmonary embolism stopped. Women aged 50-74 experienced underwent tamoxifen side effects that outweighed advantages whatever the follow-up duration and hypothesis, except the one of only beneficial remaining effect 15 years after treatment withdrawal. Overall, the slight positive effect of tamoxifen on long-term mortality should be cautiously interpreted for young women. In women aged over 50 years, however, tamoxifen chemoprevention could not be recommended.

Biologic basis of sequential and combination therapies for hormone-responsive breast cancer

Although pharmacologic therapies that reduce or block estrogen signaling are effective treatments of estrogen receptor (ER)-positive breast cancer, acquired resistance to individual drugs can develop. Furthermore, this approach is ineffective as initial therapy for a subgroup of receptor-positive patients. The mechanisms of drug resistance are not completely understood, but the presence of alternative signaling pathways for activating ER response appears to play a significant role. Cross-talk between signaling pathways can activate ERs when conventional ER pathways are blocked or inactivated. For example, signaling via epidermal growth factor or HER-2 receptors, mitogen-activated protein kinases, phosphatidylinositol 3' kinase/protein kinase B, and vascular endothelial growth factor receptor can lead to estrogen-independent stimulation of ERs and tumor growth. The discovery that alternative pathways are involved in estrogen signaling has prompted development of newer endocrine therapies, such as aromatase inhibitors and pure estrogen antagonists, with distinct mechanisms for interrupting signal transduction. The existence of multiple pathways may explain the effectiveness of follow-up therapy with a different class of endocrine agents after failure of prior endocrine treatment. Because they do not have the partial agonist activity of tamoxifen that is enhanced by the adaptive hypersensitivity process, these alternative endocrine agents may play an increasingly important role in the treatment of ER-positive breast cancer. Although optimal sequencing of these agents has not been determined and is continuing to evolve, current evidence allows rational recommendations to be made. The multiple pathways involved in activating ERs also provide a rationale for combining endocrine and non-endocrine therapies that block different signaling pathways, which may have synergistic and overlapping interactions.

Identification of a novel, orally bioavailable estrogen receptor downregulator

Tamoxifen has been widely used for the treatment of estrogen receptor (ER)-positive breast cancer, but its partial agonist activity is considered to limit the efficacy, and cause tumor flare and endometrial cancer. Fulvestrant, on the other hand, binds and degrades ER, thereby acting as a pure anti-estrogen without partial agonist activity. However, due to its low oral bioavailability, fulvestrant has to be intramuscularly administered to patients, which limits the convenience of the drug, and causes pain and inflammation at the site of injection. In search of a patient- friendly pure anti-estrogen, we screened and identified an ER antagonist, CH4893237, which bound to ER with an IC50 value of 1.4 muM and, by oral administration, inhibited estrogen-stimulated uterine growth in ovariectomized mice. CH4893237 reduced the amount of ER at the protein level and impaired the nuclear accumulation of ER, indicating an orally active pure anti-estrogen. Furthermore, CH4893237 inhibited the estrogen-stimulated proliferation of MCF-7, ZR-75-1 and BT-474 cells, and caused a marked growth inhibition of the MCF-7 xenograft in vivo. Thus, CH4893237 will provide an additional option for second-line hormone treatment of breast cancer.

Prevention of N-methyl-N-nitrosourea-induced breast cancer by alpha-fetoprotein (AFP)-derived peptide, a peptide derived from the active site of AFP

PURPOSE

alpha-Fetoprotein (AFP) is a protein of pregnancy associated with a decrease in lifetime risk of breast cancer in parous women. A synthetic, cyclic nonapeptide has been developed that mimics the antioncogenic active site of AFP. To test the hypothesis that the AFP-derived peptide (AFPep) can prevent breast cancer, the N-methyl-N-nitrosourea-induced breast cancer model was used in rats.

EXPERIMENTAL DESIGN

AFPep was given daily by injection beginning 10 days after N-methyl-N-nitrosourea treatment and continued for 23 days (a time designed to mimic pregnancy) or for other times to assess efficacy as a function of drug duration. Tumor incidence, multiplicity, and latency were noted as end points. At necropsy, pathology analysis of tumors and major organs were obtained.

RESULTS

AFPep prevented cancer in a dose-dependent fashion. Significantly longer mean tumor-free days (P < 0.02), lower tumor incidence (P = 0.004), and lower tumor multiplicity were observed for AFPep-treated groups. No evidence of host toxicity as measured by body weight, cage activity, fur texture, and organ weights (liver, uterus, heart, kidney, and spleen) were found in animals treated with AFPep. Mechanistic studies using transplantable human breast cancer xenografts showed that the peptide interfered with estrogen-dependent breast cancer growth inhibited the phosphorylation of the estrogen receptor and activated phosphorylation of p53.

CONCLUSIONS

AFPep is a well-tolerated, mechanistically novel, chemopreventive agent in models of breast cancer and warrants further development for the prevention and treatment of this disease in humans.

Ovarian cysts in tamoxifen-treated women with breast cancer

OBJECTIVE

The objective of this study was to detect any ovarian changes in tamoxifen-treated breast cancer patients.

METHODS

In all, 51 patients with breast cancer were enrolled in the study, which was conducted in the SSK (Social Security Agency) Aegean Maternity Hospital between January 1999 and December 2002. The patients' demographic and medical data were reviewed. All patients taking part in the study received tamoxifen therapy, but the duration was not uniform. Gynecological examination and transvaginal ultrasonography (TVU) were performed in each case. Any ovarian cysts or masses were identified, and serum Ca-125 levels were recorded.

RESULTS

Of the 51 tamoxifen-treated patients enrolled in this study, 24 were still premenopausal and 27 were postmenopausal when they were monitored for breast cysts during the tamoxifen treatment started after the diagnosis of breast cancer. Their average age was 53.7 (range 31-64) years. The mean duration of tamoxifen therapy was 23.5 (range 8-49) months. Ovarian cysts were diagnosed in nine (17.6%) patients and required surgery in two of these; pathological examination revealed serous cysts of the ovary in both.

CONCLUSION

: In cases with ovarian cyst formation during tamoxifen treatment of breast cancer, discontinuation of tamoxifen followed by monitoring is quite a reasonable way to proceed in most cases. Surgical intervention should be carried out when cysts are >5 cm in diameter.

The History and Mechanism of Action of Fulvestrant

Fulvestrant is a pure antiestrogen that emerged from a systematic medicinal chemistry strategy of modification of long-chain alkyl substitutes in the 7a-position of estradiol. Fulvestrant has no uterotrophic effects on the immature or ovariectomized rat and blocks the agonistic effects of estradiol and tamoxifen in a dose-dependent manner. In in vivo and in vitro breast cancer models, fulvestrant has anticancer activity at least as good as tamoxifen and is superior to tamoxifen in some models. Fulvestrant requires intramuscular administration in a proprietary formulation of castor oil and alcohols. When fulvestrant binds to estrogen receptor monomers it inhibits receptor dimerization, activating function 1 (AF1) and AF2 are rendered inactive, translocation of receptor to the nucleus is reduced, and degradation of the estrogen receptor is accelerated. This results in pure antiestrogenic effects. There is substantial preclinical evidence that the nonsteroidal hormone-dependent mechanisms of estrogen receptor activation and regulation via growth factor receptors and their signal transduction pathways are important in the development of breast cancer hormonal resistance. Methods of exploiting the interactions between these nonsteroidal hormone-dependent mechanisms of resistance and hormonal agents such as fulvestrant are an active area for drug development and clinical investigation.

Advances in estrogen receptor biology: prospects for improvements in targeted breast cancer therapy

Estrogen receptor (ER) has a crucial role in normal breast development and is expressed in the most common breast cancer subtypes. Importantly, its expression is very highly predictive for response to endocrine therapy. Current endocrine therapies for ER-positive breast cancers target ER function at multiple levels. These include targeting the level of estrogen, blocking estrogen action at the ER, and decreasing ER levels. However, the ultimate effectiveness of therapy is limited by either intrinsic or acquired resistance. Identifying the factors and pathways responsible for sensitivity and resistance remains a challenge in improving the treatment of breast cancer. With a better understanding of coordinated action of ER, its coregulatory factors, and the influence of other intracellular signaling cascades, improvements in breast cancer therapy are emerging.

Update on clinical role of tamoxifen

PURPOSE OF REVIEW

Breast cancer is the most common malignancy amongst women in the United States and decreased mortality over the past decade has been attributed to a combination of screening and adjuvant therapies. There has been a resurgence of interest in hormonal therapies and this article discusses the clinical status of tamoxifen in the context of emerging alternative agents for treatment and prevention of breast cancer.

RECENT FINDINGS

Tamoxifen has served as a prototype for the development of selective estrogen receptor modulators at the laboratory-clinical interface. Molecular technologies have permitted elucidation of mechanisms for tissue specific action and led to newer selective estrogen receptor modulators with potentially greater antitumour efficacy and attenuated uterotrophic profile. Publications over the past 12 months have emphasized the risks of thromboembolism and endometrial carcinoma associated with tamoxifen use which has accelerated application of other hormonal agents for treatment of advanced disease and as neoadjuvant therapy. This article reviews the current role of tamoxifen in the treatment of early and advanced breast cancer together with its potential for chemoprevention. Models for quantitative risk assessment are being developed to identify women for whom chemoprotection is justified.

SUMMARY

Recent data showing a survival advantage for the aromatase inhibitor letrozole compared with tamoxifen in the advanced setting and improvement in disease-free survival for the aromatase inhibitor anastrozole versus tamoxifen as adjuvant treatment may herald a major shift in standard first-line endocrine therapies for both advanced and early disease and ultimately chemoprevention of breast cancer. Other agents including newer SERMs and pure antiestrogens are undergoing phase III clinical trials and future endocrine and biological therapies are likely to include more selective and targeted therapies, which may be efficacious in both hormone-sensitive and receptor-negative disease.

Tamoxifen ("Nolvadex"): a review

Tamoxifen has been used in the management of breast cancer for over 30 years. Since its introduction for the treatment of advanced breast cancer, its indications have increased to include the treatment of early breast cancer, ductal carcinoma in situ, and more recently for breast cancer chemoprevention. Tamoxifen has a good tolerability profile and moreover, unlike many other endocrine therapies, it is efficacious in both pre- and postmenopausal women. It is the combination of efficacy and tolerability that allows tamoxifen to maintain its position as the hormonal treatment of choice for most patients with oestrogen-receptor positive breast cancer. Ongoing studies will provide further information about the optimal duration of tamoxifen therapy and how it compares with the newer aromatase inhibitors.

The effect on menstrual blood loss in women with uterine fibroids of a novel "frameless" intrauterine levonorgestrel-releasing drug delivery system: a pilot study

OBJECTIVE

To evaluate the effect on menstrual blood loss, in women with uterine fibroids, of a novel "frameless" intrauterine drug delivery system (IUS), FibroPlant-levonorgestrel (LNG), releasing 14 microg of LNG per day.

STUDY DESIGN

An open label, non-comparative ongoing pilot study. Fourteen insertions were performed in premenopausal women between 39 and 48 years of age for the treatment of menorrhagia. The effect on menstrual blood loss was evaluated using a simple visual assessment technique. Women were followed-up for at least 12 months (range 12-30 months).

RESULTS

At the time of study analysis the total number of women-months was 283. All women, except one reported greatly reduced bleeding. In two women, the treatment failed although both reported reduced bleeding. One failure (patient no. 4) was due to the presence of a large endometrial polyp. This patient underwent hysterectomy. The other women (patient no. 1) had submucosal fibroids. She refused hysterectomy and is continuing treatment. In the other 12 patients, reduction of bleeding was appreciable after one month of treatment and tended to decrease further over the next months to stabilize afterwards. The mean bleeding score before treatment was 465 (185-960) and dropped to a mean score of 100 (range 5-300) after a minimum of 12 months of treatment which is highly statistically significant (P<0.001). In eight women, the bleeding reduced to very low scores. An effect on the size of the uterine fibroids could not be demonstrated. Significant spotting was rare after the first 3 months following insertion. Neither complications (e.g. infection, expulsion or perforation) nor pregnancies occurred. The FibroPlant-LNG IUS was well tolerated by all women involved in the study and no systemic hormonal side effects were reported.

CONCLUSION

This study suggests that FibroPlant-LNG IUS is effective to significantly reduce the amount of menstrual blood loss in women with menorrhagia in the presence of intramural and subserosal fibroids and can avoid surgery. The strong endometrial suppression is the principal mechanism explaining the effect on menstrual blood loss of the IUS. The two failures probably explain that a successful treatment in women with endometrial abnormalities (e.g. polyps, submucous fibroids) is unlikely with the IUS. The low daily release rate of LNG from the FibroPlant-LNG IUS results in a low incidence of hormonal side effects. The simple design characteristics and revolutionary anchoring system account for minimizing the occurrence of complaints of pain and expulsion. The flexible fibrous delivery system adapts to cavities of every size even when severely distorted.

Tamoxifen-induced endometrial changes in postmenopausal women with breast carcinoma

OBJECTIVES

To assess the effects of tamoxifen (TAM) on the endometrium in postmenopausal women.

METHODS

A case control study of postmenopausal women with breast carcinoma, who were undergoing treatment in the Department of Radiotherapy and Surgery at the Christian Medical College Hospital, Vellore, India was done. Thirty-five women who were on tamoxifen (20 mg/day) for a period of at least 6 months formed the study group. Thirty-three women who were not receiving tamoxifen, formed the control group. Subjects in both groups had a pelvic examination and transvaginal sonogram followed by endometrial biopsy.

RESULTS

There was a statistically significant difference in the mean endometrial thickness between the study group and control group (7.8+/-6.4 mm vs. 4.0+/-2.0 mm, respectively) More women in the tamoxifen group had an endometrial thickness of >5 mm but the number of women with polyps or hyperplasia of the endometrium did not differ significantly between the two groups. There were no women with endometrial carcinoma in either group.

CONCLUSION

All patients on tamoxifen need to be evaluated by clinical examination annually. A transvaginal sonogram and endometrial biopsy/hysteroscopy may be performed on patients with abnormal vaginal bleeding, bloody discharge, staining or spotting.

A peptide derived from alpha-fetoprotein prevents the growth of estrogen-dependent human breast cancers sensitive and resistant to tamoxifen

An 8-mer peptide (EMTOVNOG) derived from alpha-fetoprotein was compared with tamoxifen for activity against growth of human breast cancer xenografts implanted in immune-deficient mice. Both peptide and tamoxifen prevented growth of estrogen-receptor-positive MCF-7 and T47D human breast cancer xenografts. A subline of MCF-7, made resistant to tamoxifen by a 6-month exposure to this drug in culture, was found to be resistant to tamoxifen in vivo. Peptide completely prevented the xenograft growth of this tamoxifen-resistant subline of MCF-7. Neither peptide nor tamoxifen was effective in slowing the xenograft growth of the estrogen-receptor-negative MDA-MB-231 human breast cancer. A worrisome side effect of tamoxifen is its hypertrophic effect on the uterus. In this study, tamoxifen was shown to stimulate the growth of the immature mouse uterus in vivo, and the peptide significantly inhibited tamoxifen's uterotrophic effect. The mechanism of action of peptide is different from that of tamoxifen in that the peptide does not interfere with the binding of [(3)H]estradiol to the estrogen receptor. In conclusion, alpha-fetoprotein-derived peptide appears to be a novel agent that interferes with the growth of tamoxifen-sensitive as well as tamoxifen-resistant estrogen-receptor-positive human breast cancers; it inhibits the uterotrophic side effect of tamoxifen and, thus, it may be useful in combination with or in place of tamoxifen for treatment of estrogen-receptor-positive human breast cancers.

Endometrial disorders in 406 breast cancer patients on tamoxifen: the case for less intensive monitoring

OBJECTIVES

To describe the endometrial appearance in postmenopausal breast cancer patients on tamoxifen and to assess a routine surveillance scheme for endometrial lesions.

STUDY DESIGN

Three hundred and seventeen postmenopausal breast cancer women already on tamoxifen at the start of the study (group I) and 89 breast cancer women assessed before any tamoxifen intake (group II) underwent an initial and then yearly scans with transvaginal ultrasonography, followed by an hysteroscopy and biopsy for women with an endometrium thickened above 8mm. Endometrial thickness was also measured in 823 women with no breast cancer nor tamoxifen intake (group III).

RESULTS

Initial mean endometrial thickness was 8.2mm in group I, 4.4mm in group II and 3.4mm in group III (P<0.001). Eighteen percent endometrial lesions were found in group I and 3.3% in group II. We observed a significant association between endometrial pathology and both cumulated dose and total duration. Polyps were the most frequent and first to appear pathology. Five cancers were detected in group I, and all of them had taken tamoxifen for more than 3 years.

CONCLUSION

Our surveillance scheme could be lightened; an acceptable screening scheme might include a baseline assessment before the start of tamoxifen and, if normal, yearly screening after 3 years of tamoxifen therapy, yearly surveillance for women with an abnormal baseline assessment and immediate investigation for symptomatic women.

Fulvestrant

Fulvestrant, a novel oestrogen receptor (ER) downregulator, is a pure anti-oestrogen which completely blocks the trophic actions of oestrogens without exerting any partial agonist effects. It reduces expression of oestrogen receptor, progesterone receptor and proliferative and cell turnover indices. The drug is well-tolerated with minimal systemic side effects. Large randomised trials have demonstrated similar efficacy to anastrozole in the treatment of postmenopausal advanced breast cancer. While results of a Phase III trial comparing fulvestrant with tamoxifen as first-line endocrine therapy for postmenopausal advanced breast cancer are awaited, future studies on its role in adjuvant and neoadjuvant settings, as well as in premenopausal women are required. With the role of tamoxifen as the gold standard of first-line therapy being challenged by the third generation aromatase inhibitors, direct comparison of the latter with fulvestrant in the first-line setting may also be worthwhile.

Development of a miniature, low-dose, frameless intrauterine levonorgestrel-releasing system for contraception and treatment: a review of initial clinical experience

A low-dose levonorgestrel (LNG)-releasing intrauterine system (IUS) (FibroPlant) has been clinically developed since 1997 for endometrial suppression during hormone replacement therapy in peri- and postmenopausal women, for the treatment of menorrhagia in women with normal uteri or with uterine fibroids, for contraception, for the treatment of endometrial hyperplasia, and for alleviating primary and secondary dysmenorrhoea. Results of preliminary studies confirm the promising nature of this all-round drug delivery system. The low dose of LNG released accounts for the low hormonal side-effect rate and virtual absence of amenorrhoea in premenopausal women. The system has not yet been evaluated in tamoxifen users (to protect the endometrium), or in women with rectovaginal endometriosis. However, early indications suggest that the system will also be suitable for these indications. The frameless drug delivery support of this LNG-releasing IUS has been optimized to reduce the size of the foreign body and to maximize tolerance and continuation of use while simultaneously providing for the maximum duration of action.

Tamoxifen and ovarian cysts: a prospective study

PURPOSE

To prospectively follow a group of women with breast cancer on tamoxifen for the development of ovarian cysts.

METHODS

72 women were followed every 6 months with pelvic examination and vaginal ultrasound. Chi square and Student's t-test were used for statistical analysis.

RESULTS

The duration of treatment was 31.5+/-20 months. The mean age was 51.2+/-9.8 years. 55.6% were post-menopausal. Out of 72 women, 18 (25%) developed ovarian cysts. The mean age of women who developed ovarian cysts was significantly lower than in those who did not (47.0+/-7.0 and 52.5+/-10.2 years, respectively, P=0.03), however, the mean duration of treatment was not significantly different (33.3+/-17.4 and 29.3+/-20 months, respectively, P=0.45). Out of 32, 14 (43.8%) pre-menopausal and out of 40, 4 (10%) post-menopausal women developed ovarian cysts (P=0.003). They developed the cysts after an average duration of 33.3+/-18 and 50.7+/-6.2 months, respectively (P=0.7). The average diameter of the cysts was 2.8+/-1.2 cm. All cysts were simple except for one pre-menopausal women. All the cysts in post-menopausal women resolved spontaneously. One pre-menopausal patient had a multi-loculated cyst, was operated and had a serious cystadenoma. In nine patients, the cysts resolved spontaneously and in three after discontinuation of tamoxifen, and one patient was lost to follow-up. All cysts were asymptomatic.

CONCLUSION

Ovarian cysts frequently develop in women with breast cancer on tamoxifen. The majority of the cysts resolve spontaneously, therefore an expectant management with follow-up ultrasonography is recommended.

Faslodex (ICI 182, 780), a novel estrogen receptor downregulator--future possibilities in breast cancer

Tamoxifen is an effective treatment for breast cancer; however, as well as exerting antagonistic effects on the estrogen receptor (ER), tamoxifen acts as a partial agonists in estrogen-sensitive tissues, resulting in stimulation of the endometrium and tumor growth in some patients who become resistant to treatment.ICI 182, 780 (Faslodex), a steroidal estrogen antagonist, is the first in a new class of agent-an estrogen receptor downregulator. Pre-clinical breast cancer models show that ICI 182, 780 leads to a prolonged duration of response, and that it exerts its effects via a different mode of action to tamoxifen. This was confirmed in a small clinical study involving 19 post-menopausal advanced breast cancer patients, where ICI 182, 780 was highly effective after tamoxifen failure. Definitive evidence of the differing modes of action of ICI 182, 780 and tamoxifen, were provided in a study involving post-menopausal women with primary breast cancer, where analyses of tumor samples following short-term exposure to both drugs, showed that ICI 182, 780 reduced tumor ER levels in a dose-dependent manner, and to a significantly greater extent than tamoxifen. Additionally, unlike tamoxifen, ICI 182, 780 did not promote ER-mediated progesterone receptor expression, indicating that it lacks estrogen agonist activity. Ongoing studies in post-menopausal women with advanced breast cancer are comparing ICI 182, 780 to anastrozole and tamoxifen, respectively. Future studies being considered are whether ICI 182, 780 may also be effective in breast cancer in pre-menopausal women, in early breast cancer and in ductal carcinoma in situ in the breast, in combination with other hormonals, cytotoxics and biological modifiers.

ICI 182,780 (Fulvestrant)--the first oestrogen receptor down-regulator--current clinical data

ICI 182,780 (Fulvestrant) is the first in a new class of novel, steroidal, 'pure' antioestrogens--the oestrogen receptor (ER) down-regulators. Its unique mode of action and the absence of partial agonist activity make it a candidate for the treatment of advanced breast cancer in both pre- and postmenopausal women. Tamoxifen has been available for use over the past 25 years. However, its partial agonist activity has been associated with detrimental effects, particularly on the endometrium, and may be associated with the development of tamoxifen resistance. Other antioestrogen agents have previously been unable to demonstrate clinically relevant activity following the development of resistance to tamoxifen. In contrast, the unique mechanism of action of ICI 182,780 results in significant clinical activity in patients failing on tamoxifen therapy. Indeed, phase III clinical trials have demonstrated that ICI 182,780 is at least as effective as the aromatase inhibitor anastrozole in the treatment of postmenopausal patients with advanced disease who have progressed during threatment with prior enocrine therapy. As such, ICI 182,780 will provide a valuable addition to the armamentarium for the treatment of advanced breast cancer.

From adjuvant therapy to breast cancer prevention: BCPT and STAR

The continued widespread prevalence of breast cancer supports placing a high priority on research aimed at its primary prevention, particularly among women who are at increased risk for developing this disease. The suggestion of potential agents for the primary chemoprevention of breast cancer evolved out of the treatment setting. Extensive experience with tamoxifen, a first-generation selective estrogen receptor modulator (SERM) showing efficacy, first, in the treatment of advanced breast cancer and, subsequently, as adjuvant therapy for early stage disease established the safety of this agent. Cumulative data from multiple adjuvant studies documented the efficacy of tamoxifen in reducing second primary breast cancers in the contralateral breast, supporting its potential as a chemopreventive agent for breast cancer. The safety and second primary data on tamoxifen, together with extensive information on its pharmacokinetics, metabolism, and antitumor effects, as well as its potentially beneficial effects on lipid metabolism and osteoporosis, led the National Surgical Adjuvant Breast and Bowel Project (NSABP) to select tamoxifen for testing in the first prospective randomized phase III trial of the efficacy of a chemopreventive agent for preventing breast cancer in women at increased risk of the disease. Accordingly, in 1992 the NSABP started the Breast Cancer Prevention Trial (P-1) in which 13,388 women > or = 35 years of age who were at increased risk of breast cancer according to Gail model risk factors [family history, age, and personal history (i.e., age at first birth, age at menarche, previous breast biopsies)] were randomized to tamoxifen 20 mg/day or placebo for 5 years. Through 69 months of follow-up tamoxifen reduced the risk of invasive breast cancer, primarily estrogen receptor-positive tumors, by 49% (two-sided p < 0.00001). Tamoxifen reduced the risk of noninvasive breast cancer by 50% (two-sided p < 0.002). In addition, tamoxifen reduced fractures of the hip, radius, and spine, but it had no effect on the rate of ischemic heart disease. As previously shown, the rates of endometrial cancer and vascular events increased with tamoxifen. With the P-1 results establishing tamoxifen as the standard of care for the primary chemoprevention of breast cancer in high-risk women, concern over the side effects of tamoxifen has prompted a continuing search for an agent that displays a more desirable efficacy/toxicity profile. Raloxifene, a second-generation SERM approved for the prevention of osteoporosis in postmenopausal women, displays antiestrogenic properties in the breast and possibly the endometrium, and estrogenic effects in the bone and on the lipid profile, suggesting it as a candidate for comparison with the chemopreventive standard, tamoxifen. Raloxifene will be compared to tamoxifen in an equivalency trial, the Study of Tamoxifen and Raloxifene (STAR) NSABP P-2, which began in July 1999 at almost 500 centers in North America. The plan is to randomize 22,000 postmenopausal women > or = 35 years of age at increased risk of breast cancer by Gail criteria to tamoxifen 20 mg/day or raloxifene 60 mg/day for 5 years. Study endpoints include invasive and noninvasive breast cancer, cardiovascular disease, endometrial cancer, bone fractures, and vascular events.

Effect of adjuvant tamoxifen on the endometrium in women with breast cancer: a prospective study using office endometrial biopsy

PURPOSE

To determine the frequency of developing abnormal pathologic changes in the endometria of tamoxifen-treated women. To characterize the type of pathologic changes involved.

PATIENTS AND METHODS

Between October 1991 and September 1998, 159 patients initiating tamoxifen therapy for breast cancer confined to the breast and axillary lymph nodes were entered in a prospective study. In this study, office endometrial biopsies (EMBs) were obtained during the initiation of tamoxifen and at 6-month intervals for a 2-year period. Three subsequent annual EMBs were recorded for each patient, amounting to a 5-year surveillance.

RESULTS

One hundred fifty-nine patients with a median age of 50 years were entered onto study. Patients were assessable if EMBs were performed at least 1 year after the initiation of tamoxifen treatment. Nine patients (5. 7%) were considered protocol violations. The remaining 111 assessable patients underwent a total of 635 EMBs (mean, 5.8 EMBs), with a median surveillance time of 36 months. Eighty-two (12.9%) of the 635 biopsies revealed tissue insufficient for diagnosis. Fourteen patients (12.6%) underwent dilation and curettage (D&C) for an abnormal EMB, persistent bleeding, or for evaluation of adnexal masses at the time of laparoscopy. Findings at D&C included complex hyperplasia (n = 1), abnormal histiocytes (n = 1), simple hyperplasia (n = 2), polyps (n = 4), endocervical polyp (n = 1), and decidualization (n = 2). Three D&Cs were negative. Three patients have undergone hysterectomy.

CONCLUSION

EMB was used to monitor the endometrium in the majority (95%) of breast cancer patients on tamoxifen in this trial, but the utility of routine EMB for screening in tamoxifen-treated women seems limited.

Selective estrogen receptor modulators: structure, function, and clinical use

The sex hormone estrogen is important for many physiologic processes. Prolonged stimulation of breast ductal epithelium by estrogen, however, can contribute to the development and progression of breast cancer, and treatments designed to block estrogen's effects are important options in the clinic. Tamoxifen and other similar drugs are effective in breast cancer prevention and treatment by inhibiting the proliferative effects of estrogen that are mediated through the estrogen receptor (ER). However, these drugs also have many estrogenic effects depending on the tissue and gene, and they are more appropriately called selective estrogen receptor modulators (SERMs). SERMs bind ER, alter receptor conformation, and facilitate binding of coregulatory proteins that activate or repress transcriptional activation of estrogen target genes. Theoretically, SERMs could be synthesized that would exhibit nearly complete agonist activity on the one hand or pure antiestrogenic activity on the other. Depending on their functional activities, SERMs could then be developed for a variety of clinical uses, including prevention and treatment of osteoporosis, treatment and prevention of estrogen-regulated malignancies, and even for hormone replacement therapy. Tamoxifen is effective in patients with ER-positive metastatic breast cancer and in the adjuvant setting. The promising role for tamoxifen in ductal carcinoma-in-situ or for breast cancer prevention is evolving, and its use can be considered in certain patient groups. Other SERMs are in development, with the goal of reducing toxicity and/or improving efficacy, and future agents have the potential of providing a new paradigm for maintaining the health of women.

ICI 182,780 (Faslodex): development of a novel, "pure" antiestrogen

BACKGROUND

The nonsteroidal antiestrogen tamoxifen is well established as an effective treatment for patients with breast carcinoma, both for the treatment of metastatic disease and as an adjuvant to surgery for patients with primary breast carcinoma. In addition to exerting antagonistic effects on the estrogen receptor, tamoxifen and its derivatives act as partial agonists on certain tissues. These agonistic effects, for example, endometrial stimulation and stimulation of tumor growth after previous response to tamoxifen, may limit their clinical efficacy. ICI 182,780 (Faslodex) from AstraZeneca (Cheshire, United Kingdom) is a novel, steroidal estrogen antagonist that was designed to be devoid of estrogen agonist activity in preclinical models.

METHODS

ICI 182,780 was tested in a large number of in vitro and in vivo preclinical models, and its value was assessed clinically when administered before surgery for breast carcinoma and hysterectomy for benign conditions and after failure of tamoxifen in patients with advanced breast carcinoma.

RESULTS

All data indicated that ICI 182,780 is devoid of agonist activity in preclinical models and in clinical trials. It inhibits growth of the breast and endometrium. In animal models, it does not cross the blood-brain barrier and appears to be neutral with respect to lipids and bone. ICI 182,780 down-regulates the estrogen receptor and is active in tamoxifen-resistant breast carcinoma. In a small, Phase II study, durable responses were seen: Phase III clinical trials are in progress comparing ICI 182,780 with anastrozole and tamoxifen in the treatment of patients with advanced breast carcinoma.

CONCLUSIONS

ICI 182,780 specifically down-regulates the estrogen receptor and, thus, represents the first of a new class of therapeutic agents. In this report, the authors present the current evidence that distinguishes ICI 182,780 from tamoxifen and related nonsteroidal compounds and establishes ICI 182,780 as the first in a new class of therapeutic agents.

Saline sonohysterography for monitoring asymptomatic postmenopausal breast cancer patients taking tamoxifen

OBJECTIVES

To evaluate the effectiveness of sonohysterography for monitoring asymptomatic postmenopausal breast cancer patients on long-term tamoxifen therapy.

METHODS

Thirty-eight asymptomatic postmenopausal patients receiving tamoxifen for breast cancer were enrolled into the study. The endometrium of study subjects was measured by transvaginal ultrasound. If a distinct echo measured < or = 5 mm, no further procedure was performed. For thickened or inadequately visualized endometrium by transvaginal ultrasound (TVS), sonohysterography was performed. Endometrial biopsies were performed for patients with generalized symmetrical changes on sonohysterography. In cases with focal changes, or inadequate SHG, hysteroscopy/dilatation and curettage (D&C) were performed.

RESULTS

Transvaginal ultrasound examination showed 12 (31.6%) patients with thin endometrium < or = 5 mm, 18 (47.4%) cases with thickened endometrium while eight (21%) cases were not adequately visualized by TVS. Sonohysterography was satisfactorily performed in 22 of 26 (84.6%) cases. Of these, three cases showed thin endometrium, 10 patients had endometrial polyps (45.5%) and nine patients showed abnormal endometrial-myometrial junction. Histology revealed hyperplasia in three cases and well differentiated adenocarcinoma associated with one polyp. Endometrial curettage for cases with abnormal endometrial-myometrial junction showed endometrial hyperplasia in two cases. Hysteroscopy and D&C were performed for four (15.4%) patients where SHG was unsuccessful, histopathology revealed inactive endometrium in three cases and one was hyperplastic.

CONCLUSIONS

Sonohysterography is superior to unenhanced transvaginal sonography in specifying the abnormal ultrasonographic appearance induced by prolonged tamoxifen therapy, it is easily performed, cost-effective and very well tolerated by the patients with no complications. Sonohysterography is recommended as a minimally invasive diagnostic tool for the assessment of endometrial changes in asymptomatic postmenopausal breast cancer patients on long-term tamoxifen therapy with thickened endometrium or inadequately visualized endometrial echo on transvaginal sonography.

Tamoxifen and endometrial pathologies: a prospective study

OBJECTIVE

The purpose of this study was to prospectively follow a group of women with breast cancer, on tamoxifen, for the development of endometrial pathologies.

MATERIALS AND METHODS

Eighty women with breast cancer, on tamoxifen, were prospectively followed every 6 months with pelvic examination, Pap smear, vaginal ultrasound, and endometrial biopsy.

RESULTS

Nine women were lost to follow-up prior to initiation of treatment and 4 refused biopsies, leaving 67 patients for evaluation. Fifty (74.6%) of the 67 patients were already on tamoxifen for a mean duration of 15.8 +/- 16.6 months and had a baseline benign, unremarkable endometrium at the time of entry into the study. The total duration of treatment was 32.5 +/- 19.6 months (median 30 months). The mean age of the patients was 51.7 +/- 9.9 years (median 52 years). Of the patients, 56.7% were postmenopausal. Sixty-three patients had a benign endometrium (mean age 51.8 +/- 10.1 years, mean duration 33.1 +/- 19.6 months). Two patients had simple hyperplasia (mean age 43.5 years, duration 28.5 +/- 33.2 months), 1 patient had complex hyperplasia with atypia (age 57 years, duration 13 months), and another patient developed adenocarcinoma (grade 3) after 22 months. These 4 patients had abnormal vaginal bleeding. Seven patients developed endometrial polyps (mean age 54.0 +/- 8.5 years, duration 36 +/- 24.2 months). The mean endometrial thickness for patients with histologically unremarkable and abnormal endometrium was not significantly different (7.6 +/- 3.9 vs 8.8 +/- 5.0 mm, respectively) (median 7.0 mm for both groups). No endometrial thickness cutoff point reached statistical significance. The patient who developed endometrial cancer had a thickness of only 3 mm.

CONCLUSION

All patients who developed an abnormal endometrium had abnormal vaginal bleeding. There was no correlation between endometrial thickness and endometrial pathology; thus the value of routine screening remains controversial.

Phase III, large-scale chemoprevention trials. Approach to chemoprevention clinical trials and phase III clinical trial of tamoxifen as a chemopreventive for breast cancer--the US National Cancer Institute experience

Clinical trials to evaluate interventions for cancer prevention are designed as early (phase I, IIa, and IIb) or late-phase studies. Whereas the former are small and generally rely on intermediate endpoint biomarkers of carcinogenesis, the latter are large-scale, long-term, randomized, phase III studies that address endpoints such as cancer incidence. The Breast Cancer Prevention Trial, P-1, conducted by the National Surgical Adjuvant Breast and Bowel Project (NSABP), is discussed as an example of a large, extended, phase III trial designed to answer the question of whether tamoxifen reduces the incidence of breast cancer in women who are at increased risk for the disease.

Gynecologic health and disease

Traditionally the obstetrician/gynecologist has been the sole provider of health care for women. As the United States moves toward a system of greater managed care, however, family practitioners, internists, and other physician extenders (physician assistants, nurse-practitioners, and nurse-midwives) are the first-line providers for many women. These practitioners have the opportunity to influence behavioral changes and promote healthy habits by identifying risk factors and their potential consequences.