Effect of tamoxifen on bone fractures in older nursing home residents

Adjuvant Endocrine Therapy and Bone Health in Breast Cancer

Breast cancer is one of the most common malignancies of women. The majority of breast cancers express estrogen and/or progesterone receptors, permitting anticancer targeting strategies to reduce estrogen signaling in the cancer cells and thereby lowering the risk of breast cancer recurrence. The development of the selective estrogen receptor modulator (SERM) tamoxifen marked a significant milestone in breast cancer care that transcended older estrogen ablative strategies such as oophorectomy and ovarian irradiation. An unintended benefit of tamoxifen in postmenopausal women was bone density preservation. The third generation of aromatase inhibitors (AIs) have demonstrated superior efficacy to tamoxifen in improving disease-free survival in postmenopausal women. However, the AIs significantly increase bone resorption, reduce bone mineral density, and increase the risk of fracture above that of tamoxifen. As a consequence of this, clinical oncologists have assumed a larger role in the screening and treatment of the skeletal complications of breast cancer therapies. The key features of managing bone health in women with early stage breast cancer receiving adjuvant endocrine therapy are reviewed here.

Oral low dose and topical tamoxifen for breast cancer prevention: modern approaches for an old drug

Tamoxifen is a drug that has been in worldwide use for the treatment of estrogen receptor (ER)-positive breast cancer for over 30 years; it has been used in both the metastatic and adjuvant settings. Tamoxifen's approval for breast cancer risk reduction dates back to 1998, after results from the Breast Cancer Prevention Trial, co-sponsored by the National Cancer Institute and the National Surgical Adjuvant Breast and Bowel Project, showed a 49% reduction in the incidence of invasive, ER-positive breast cancer in high-risk women. Despite these positive findings, however, the public's attitude toward breast cancer chemoprevention remains ambivalent, and the toxicities associated with tamoxifen, particularly endometrial cancer and thromboembolic events, have hampered the drug's uptake by high-risk women who should benefit from its preventive effects. Among the strategies to overcome such obstacles to preventive tamoxifen, two novel and potentially safer modes of delivery of this agent are discussed in this paper. Low-dose tamoxifen, expected to confer fewer adverse events, is being investigated in both clinical biomarker-based trials and observational studies. A series of systemic biomarkers (including lipid and insulin-like growth factor levels) and tissue biomarkers (including Ki-67) are known to be favorably affected by conventional tamoxifen dosing and have been shown to be modulated in a direction consistent with a putative anti-cancer effect. These findings suggest possible beneficial clinical preventive effects by low-dose tamoxifen regimens and they are supported by observational studies. An alternative approach is topical administration of active tamoxifen metabolites directly onto the breast, the site where the cancer is to be prevented. Avoidance of systemic administration is expected to reduce the distribution of drug to tissues susceptible to tamoxifen-induced toxicity. Clinical trials of topical tamoxifen with biological endpoints are still ongoing whereas pharmacokinetic studies have already shown that appropriate formulations of drug successfully penetrate the skin to reach breast tissue, where a preventive effect is sought.

Bone health in adult cancer survivorship

Optimizing health outcomes, including prevention of osteoporotic fractures, is essential for promoting the well-being of the growing number of cancer survivors. Medical providers who participate in the care of cancer survivors should be aware that various cancer treatments may cause bone loss, which can increase the risk of subsequent of osteoporosis. Healthy bone remodeling is a balanced and dynamic equation between new bone formation and bone resorption. Aging, natural menopause, and cancer treatments such as surgical oophorectomy, gonadotropin-releasing hormone agonists, chemotherapy-induced ovarian failure, androgen deprivation therapy, and aromatase inhibitors can all promote bone loss. The WHO Fracture Assessment Tool can be used as a clinical aid to assess an individual's osteoporotic fracture risk, with or without bone mineral density measurements obtained from dual-energy x-ray absorptiometry. Preventative strategies include adequate calcium and vitamin D supplementation and modifying risk factors such as alcohol intake, tobacco use, and lack of exercise. Bisphosphonate therapy and rank-ligand monoclonal antibody therapy are the most commonly used agents for management of bone loss resulting from cancer treatment. This review will summarize the mechanisms by which cancer treatments cause bone loss as well provide screening and treatment recommendations for the management of bone loss.

Minimal trauma fractures: lifting the specter of misconduct by identifying risk factors and planning for prevention

Minimal trauma fractures are an unfortunate, yet not uncommon, event for frail elderly individuals in long term care facilities. These fractures result in significant morbidity including pain and loss of function along with significantly increased mortality. Further concern exists for the medico-legal issues raised after a minimal trauma fracture is discovered. The controversy at hand is whether such fractures are primarily the result of inadequate, careless, or abusive care practices. We build a case to the contrary. Although the data regarding this condition are limited, there exists a reasonable evidence base to identify an at-risk patient population. We present a representative case and subsequent literature review of minimal trauma fractures to illustrate the condition, including risk factors, mode of presentation, and patient outcomes. No direct research has been conducted on the pathophysiology of these fractures. Extrapolating from other similar conditions and likely associated comorbid illnesses, we explore possible physiologic explanations for their occurrence. Again, no direct investigation into prevention or treatment of minimal trauma fractures has been published. Instead, we consider a variety of pharmacologic and nonpharmacologic interventions that may modify the risk for minimal trauma fractures considering the previously identified risk factors and probable pathophysiologic changes leading to fracture development. We propose that reducing minimal trauma fractures in the frail elderly nursing home population will require careful staff education, close attention to identify at-risk patients, and implementation of select interventions aimed at preventing such fractures.

DT56a (Femarelle): a natural selective estrogen receptor modulator (SERM)

A selective estrogen receptor modulator (SERM) is defined as a substance with dissimilar effects on different tissues: agonist in some and antagonists in others. The natural compound DT56a (Femarelle) was shown to activate estrogen receptors in human cultured female derived osteoblasts. It was also shown to relieve menopausal symptoms and to increase bone mineral density with no effect on sex steroid hormone levels and on the endometrial thickness. DT56a, similarly to estradiol-17beta (E2), stimulated the specific activity of creatine kinase (CK) in skeletal and vascular tissues of female rats, as a marker of estrogen receptor (ER) activation. However, in the uterus, CK was activated only by E2 but not by DT56a. In order to prove that DT56a is a SERM, we examined the mutual interaction between DT56a and E2, at supra physiological doses, in different tissues in both intact and ovariectomized female rats, as well as in human cultured vascular and bone cells. Administration of DT56a or E2 stimulated CK in all tissues tested, but when given simultaneously, in intact immature female rats, DT56a completely abolished E2 stimulation of CK in all organs except in the diaphyseal bone where the inhibition was partial. In ovariectomized female rats, DT56a abolished E2's stimulation of CK in diaphyseal bone, thymus, uterus and pituitary but caused a partial inhibition in aorta, left ventricle and epiphyseal cartilage. In human bone cells E2 stimulation of CK, of alkaline phosphatase (AP) activity and of DNA synthesis was completely abolished by DT56a in post-menopausal cells and partially inhibited in pre-menopausal cells. In human vascular cells, inhibition of DNA synthesis by E2 was completely abolished by DT56a and E2-induced CK was partially inhibited by DT56a. The results support the finding that DT56a is a SERM; it stimulated different parameters similar to E2, but when given simultaneously, at supra physiological doses, inhibited these E2's effects. Further investigations regarding intra and extra cellular mechanism of action of DT56a are currently performed.

SERMs in chemoprevention of breast cancer

Selective estrogen receptor modulators (SERMs) play a key role in breast cancer chemoprevention. Tamoxifen has been shown to reduce breast cancer incidence by 30-40% in at-risk subjects in large phase III trials. However, toxicity may be a limiting factor. Thus, different strategies are being pursued to improve the risk: benefit ratio of using these compounds in chemoprevention. Firstly, the second generation SERM raloxifene is currently undergoing evaluation in comparison with tamoxifen in a large phase III trial. Also, lower doses of tamoxifen are being assessed in phase II-III trials. In addition, the combination of hormone replacement therapy (HRT) or aromatase inhibitors and tamoxifen at low doses may reduce the risks while retaining the benefits of either agents. Finally, new agents that interfere with the onset of ER-negative breast cancer are being sought for combination chemoprevention since almost a third of breast cancers will not be sensitive to hormonal modulation.

Are Oral Bisphosphonates Effective in Improving Lumbar Bone Mineral Density in Breast Cancer Survivors With Osteopenia or Osteoporosis?

OBJECTIVE

Breast cancer survivors with osteoporosis or osteopenia are commonly encountered in primary care and gynaecology practices. Our objective was to determine whether treatment with oral bisphosphonates (alendronate or cyclic etidronate) was more effective than calcium with vitamin D in improving lumbar spine bone mineral density (BMD) within one year in breast cancer survivors.

METHODS

Breast cancer survivors with at least one year of clinical follow-up were identified from the prospective observational Canadian Database of Osteoporosis and Osteopenia (CANDOO). Analysis of covariance was used to examine the effects of bisphosphonate therapy on change in lumbar spine BMD at one year compared with the effects of calcium with vitamin D (analysis adjusted for baseline L2-L4 BMD, current tamoxifen use, number of prevalent vertebral fractures [VFs], and time since diagnosis of breast cancer, and age).

RESULTS

Eighteen patients took calcium and vitamin D, 25 took cyclic etidronate, and 27 took oral alendronate. Adjusted one-year BMD increases for alendronate and cyclic etidronate compared to calcium and vitamin D were as follows: alendronate 4.53% (95% confidence interval [CI] 1.26%, 7.81%, P = 0.008), and cyclic etidronate 1.85% (-1.55%, 5.25%, P = 0.280). BMD increases were significantly greater in patients with prevalent VF compared to those without VF (P = 0.025). In contrast, time since diagnosis of breast cancer was significantly associated with a decrease in BMD (P = 0.002). We were unable to detect any effect of current tamoxifen use, baseline lumbar spine BMD, or age on changes in BMD at one year.

CONCLUSION

Treatment with alendronate was associated with significantly greater improvements in lumbar spine BMD within one year in breast cancer survivors when compared with treatment with cyclic etidronate or calcium and vitamin D.

Tamoxifen for breast cancer prevention: a framework for clinical decisions

OBJECTIVE

Given the potential side effects and an uncertain survival benefit, decisions about tamoxifen treatment for the primary prevention of breast cancer remain complex. Primary care providers, including gynecologists, will need to counsel patients regarding this form of preventive care. In this report, we update cost-effectiveness calculations for tamoxifen chemoprevention and establish reasonable parameters for clinicians' use.

METHODS

We performed a cost-effectiveness analysis that compared women aged 50 years who were treated with tamoxifen for 5 years with an untreated cohort. In the base model, we assumed a 3.4% 5-year breast cancer risk. Quality-of-life estimates for important outcomes (breast cancer, endometrial cancer, deep venous thrombosis, pulmonary embolism, stroke, metastatic cancer, and hot flushes) were obtained from 106 women. Probabilities and costs of outcomes were derived from the Breast Cancer Chemoprevention Trial and other published estimates. Broad sensitivity analyses were performed. Cost per quality-adjusted life-year gained as a result of tamoxifen breast cancer prevention was the main outcome measure.

RESULTS

The use of tamoxifen led to a remaining life expectancy of 26.07 quality-adjusted life-years compared with 25.97 without treatment. The cost per quality-adjusted life-year gained was $43,300. Sensitivity analysis revealed that younger age, the absence of the uterus, higher initial risk of breast cancer, increased fear of curable breast cancer, and reduced tamoxifen cost further favored treatment.

CONCLUSION

Tamoxifen chemoprevention is cost-effective for women aged 40-50 years who are at significant breast cancer risk. Whether this holds true for older women depends on the initial breast cancer risk, fear of breast cancer, and presence of the uterus.

Progress in chemoprevention of breast cancer

Primary prevention trials have shown that tamoxifen lowers breast cancer incidence by 30-40%. Because of the endometrial risk of tamoxifen and the pro-thrombotic effects of tamoxifen and raloxifene, different strategies are being pursued to improve the risk:benefit ratio of breast cancer chemoprevention. Thus, raloxifene is being compared with tamoxifen in a phase III trial, while the minimal active dose of tamoxifen is being assessed in phase I-II trials. Also, the combination of hormone replacement therapy (HRT) and tamoxifen may reduce the risks while retaining the benefits of either agent. Anastrozole holds promise as a preventive agent based on preliminary results on contralateral breast cancer. The identification of women at increased risk for estrogen receptor (ER)-positive breast cancer due to hormonal and reproductive factors may maximize the therapeutic index of hormonal agents. Finally, new targets that interfere with ER-negative breast carcinogenesis are being sought as one-third of breast cancers will not be preventable by hormonal interventions.

HRT opposed to low-dose tamoxifen (HOT study): rationale and design

The rationale for the HOT study is mainly based on the findings of the Italian Tamoxifen Prevention Study, where 5,408 healthy hysterectomized women aged 35-70 years were randomized to 20 mg/day of tamoxifen or placebo for 5 years. After 81.2 months median follow-up, 79 breast cancers occurred (34 on tamoxifen versus 45 on placebo, p=0.215). In the subgroup of 1,580 women who used estrogen replacement therapy (ERT) at some point during the study, 23 breast cancers were observed: 17 on placebo and 6 on tamoxifen (hazard ratio=0.35, 95% CI, 0.14-0.89). Pharmacokinetic and pharmacodynamic (surrogate endpoint biomarkers) studies showed that a lower dose of tamoxifen (such as 5 mg/day) does not affect the drug's activity on several biomarkers of both cardiovascular and breast cancer risk. We therefore propose a multicenter placebo-controlled phase III trial in postmenopausal healthy women on hormone replacement therapy (HRT) to assess whether the combination of HRT and low-dose tamoxifen retains the benefits while reducing the risks of either.

Pharmacological prevention of breast cancer: quo vadis?

Although tamoxifen reduces breast cancer incidence by 30-40% in at-risk subjects, its adverse events may be a limiting factor. Thus, different strategies are being pursued to improve the risk:benefit ratio of breast cancer chemoprevention intervention. Firstly, raloxifene is being compared with tamoxifen in a phase-III trial, whereas the minimal active dose of tamoxifen is being assessed in phase I-II trials. The combination of HRT and tamoxifen may also reduce the risks while retaining the benefits of either agent. Anastrozole holds promise as a preventive agent based on preliminary data on contralateral breast cancer. Another important area is the appropriate identification of women at increased risk for ER-positive breast cancer due to reproductive factors, which may maximize the therapeutic index of hormonal agents. Finally, new targets that interfere with the onset of ER-negative breast cancer are being sought since one-third of breast cancers will not be modulated by hormonal interventions.

Osteopenia and osteoporosis in women with breast cancer

Osteopenia and osteoporosis are prevalent in women. Epidemiologic studies show that the risk of breast cancer is greater in postmenopausal women with higher bone mineral density (BMD). Standard treatments for breast cancer such as adjuvant chemotherapy or hormonal therapy can increase bone loss, and hence may increase the risk of osteoporosis. Premenopausal women treated with standard adjuvant chemotherapy frequently develop permanent ovarian failure, or early menopause. Ovarian failure is associated with accelerated bone loss, and bisphosphonates may mitigate this bone loss in women treated with adjuvant chemotherapy. Tamoxifen preserves BMD in postmenopausal women; however, in premenopausal women tamoxifen may increase bone loss. Anastrazole, an aromatase inhibitor, is approved for adjuvant treatment of postmenopausal women with early-stage, estrogen receptor-positive breast cancer. With a follow-up duration of less than 5 years, anastrazole-treated women experience increased fractures relative to those treated with tamoxifen. The management of osteopenia and osteoporosis in women with breast cancer generally does not differ from women without breast cancer. Adequate dietary calcium and vitamin D intake, encouraging weight-bearing exercise, and counseling about the relationship between smoking and alcohol and bone loss are all prudent recommendations for overall health and may lessen bone loss and the risk of subsequent osteoporosis. BMD should be measured in women with chemotherapy-induced ovarian failure, and in those on aromatase inhibitors. Bisphosphonates reduce the bone loss associated with chemotherapy-induced ovarian failure, and clinical trials evaluating third-generation bisphosphonates in women with chemotherapy-induced ovarian failure are underway. As many women with breast cancer will be long-term survivors, increasing recognition of maintaining skeletal health is important.

DT56a (Tofupill/Femarelle) selectively stimulates creatine kinase specific activity in skeletal tissues of rats but not in the uterus

The novel natural product DT56a (Tofupill/Femarelle), derived from soybean, has been shown to relieve menopausal vasomotor symptoms and to increase bone mineral density with no effect on sex steroid hormone levels or endometrial thickness. In the present study, we compared the effects of DT56a and estradiol-17beta (E2) on bone and cartilage (Ep) of immature or ovariectomized female rats, by measuring the changes in the specific activity of the BB isozyme of creatine kinase (CK). Single short-term injection of high doses of DT56a induced estrogenic activity in bones and uterus similar to that of E2. When administered in multiple oral doses, DT56a stimulated skeletal tissues similarly to E2, but whereas E2 increased CK specific activity in the uterus, DT56a did not. The selective estrogen receptor modulator (SERM) raloxifene (Ral) blocked the stimulation of CK by either DT56a or by E2 in all tissues tested. Our findings suggest that DT56a acts as a selective estrogen receptor modulator stimulating skeletal tissues without affecting the uterus. The effect of DT56a on other systems, such as the vascular and the central nervous system, are currently under investigation.

Effects of low dose tamoxifen on normal breast tissue from premenopausal women

The aim of this study was to determine the effects of low doses of tamoxifen (5 and 10mg/day) for 50 days compared with the standard dose (20 mg/day) on breast biomarkers measured in normal breast tissue from premenopausal patients. A randomised double-blind study was performed using tissue from 56 premenopausal women with a diagnosis of fibroadenoma of the breast. Excisional biopsy was performed on the 50th day of therapy. Normal breast tissue samples were collected during surgery. The patients were divided in groups: A (placebo, n=11); group B (5 mg, n=16), group C (10 mg, n=14) and group D (20 mg, n=15). In this cross-sectional study, differences in the expression of Oestrogen Receptor alpha (ERalpha), Progesterone Receptor (PR), Ki-67, apoptotic bodies and mitotic index between the different groups after treatment can be seen on the normal breast tissue. We believe that a lower dose of tamoxifen could reduce the side-effects associated with treatment without affecting its chemopreventive activity in the breast.

Selective estrogen receptor modulators

Because of recent concerns about the long-term risks of estrogen replacement therapy in postmenopausal women, there is growing interest in a group of compounds known as selective estrogen receptor modulators (SERMs). The SERMs bind to estrogen receptors and have tissue-specific effects that allow them to function as estrogen agonists in some tissues and estrogen antagonists in other tissues. There are four SERMs currently marketed in the United States. These include the triphenylethylenes--clomiphene citrate (Clomid), tamoxifen, and toremifene--and the benzothiophene, raloxifene. Clomid is used primarily in the treatment of infertility. Tamoxifen is indicated for the treatment and prevention of breast cancer. It has an estrogen antagonist effect on breast tissue, but an estrogen-like effect on lipids, bone, and the endometrium. Toremifene has an antagonist/agonist profile similar to that of tamoxifen. Raloxifene is approved for the prevention of osteoporosis in postmenopausal women. It is thought to be an estrogen antagonist on the uterus and breast tissues and an estrogen agonist with respect to bone and serum lipids.

Human osteoblasts' proliferative responses to strain and 17beta-estradiol are mediated by the estrogen receptor and the receptor for insulin-like growth factor I

The mechanism by which mechanical strain and estrogen stimulate bone cell proliferation was investigated using monolayer cultures of human osteoblastic TE85 cells and female human primary (first-passage) osteoblasts (fHOBs). Both cell types showed small but statistically significant dose-dependent increases in [3H]thymidine incorporation in response to 17beta-estradiol and to a single 10-minute period of uniaxial cyclic strain (1 Hz). In both cell types, the peak response to 17beta-estradiol occurred at 10(-8) - 10(-7) M and the peak response to strain occurred at 3500 microstrain ((mu)epsilon). Both strain-related and 17beta-estradiol-related increases in [3H]thymidine incorporation were abolished by the estrogen receptor (ER) modulator ICI 182,780 (10-8 M). Tamoxifen (10(-9) - 10(-8) M) increased [3H]thymidine incorporation in both cell types but had no effect on their response to strain. In TE85 cells, tamoxifen reduced the increase in [3H]thymidine incorporation associated with 17beta-estradiol to that of tamoxifen alone but had no such effect in fHOBs. In TE85 cells, strain increased medium concentrations of insulin-like growth factor (IGF) II but not IGF-I, whereas 17beta-estradiol increased medium concentrations of IGF-I but not IGF-II. Neutralizing monoclonal antibody (MNAb) to IGF-I (3 microg/ml) blocked the effects of 17beta-estradiol and exogenous truncated IGF-I (tIGF-I; 50 ng/ml) but not those of strain or tIGF-II (50 ng/ml). Neutralizing antibody to IGF-II (3 microg/ml) blocked the effects of strain and tIGF-II but not those of 17beta-estradiol or tIGF-I. MAb aIR-3 (100 ng/ml) to the IGF-I receptor blocked the effects on [3H]thymidine incorporation of strain, tIGF-II, 17beta-estradiol, and tIGF-I. HOBs and TE85 cells, act similarly to rat primary osteoblasts and ROS 17/2.8 cells in their dose-related proliferative responses to strain and 17beta-estradiol, both of which can be blocked by the ER modulator ICI 182,780. In TE85 cells (as in rat primaries and ROS 17/2.8 cells), the response to 17beta-estradiol is mediated by IGF-I, and the response to strain is mediated by IGF-II. Human cells differ from rat cells in that tamoxifen does not block their response to strain and reduces the response to 17beta-estradiol in TE85s but not primaries. In both human cell types (unlike rat cells) the effects of strain and IGF-II as well as estradiol and IGF-I can be blocked at the IGF-I receptor.

The Italian breast cancer prevention trial with tamoxifen: findings and new perspectives

The Italian Tamoxifen Prevention Study includes 5408 healthy hysterectomized women aged 35-70 years who have been randomized to 20 mg/day of tamoxifen or placebo for 5 years. After 46 months median follow-up, an increased risk of venous vascular events (38 women on tamoxifen vs. 18 women on placebo, P = 0.0053), mainly consisting of superficial phlebitis, has been observed and 41 breast cancers have occurred (19 on tamoxifen vs. 22 on placebo, P = 0.64). However, subgroup analyses indicated a borderline significant reduction of breast cancer among women continuously on estrogen replacement therapy (ERT, mostly transdermal) and receiving tamoxifen, with 8 cases of breast cancer among 390 ERT users on placebo versus 1 case among 362 ERT users on tamoxifen (RR = 0.13, 95% CI = 0.02-1.02). Withdrawal rate (mainly due to menopausal symptoms) differed according to ERT use, with compliance being 78% and 75% at 3 and 5 years, respectively, for women who never took ERT, and 92% and 88% at 3 and 5 years, respectively, for women not on ERT at baseline, but who took ERT at some time during the trial. Pharmacokinetic and pharmacodynamic (surrogate end point biomarkers) studies showed that a lower dose of tamoxifen (such as 5 mg/day) does not affect the drug's activity on several biomarkers of both cardiovascular and breast cancer risk. We are therefore planning a multicenter placebo-controlled phase III trial in postmenopausal healthy women on hormone replacement therapy (HRT) to test whether the combination of HRT and low-dose tamoxifen retains the benefits while reducing the risks of either agent maintaining a high compliance rate.

The relationship of tamoxifen with dementia, depression, and dependence in activities of daily living in elderly nursing home residents

OBJECTIVES

To evaluate the association between tamoxifen treatment and the prevalence of Alzheimer's disease, other dementias, depression, and the levels of dependence in activities of daily living (ADL) in elderly, nursing home residents.

PARTICIPANTS

93,031 women, at least 65 years old, whose data were part of the 1993 New York State MDS, and for whom there was documentation of treatment with at least one medication.

SETTING

New York State long-term care facilities.

DESIGN

Cross-sectional study via secondary analysis of 1,385 matched sets of residents. Each set included one resident who received tamoxifen treatment and up to four residents who did not.

MEASUREMENTS

Included age, ethnicity, tamoxifen treatment, hormone replacement therapy, depression, levels of dependence in ADL and in cognitive skills for daily decision-making, and documentation of Alzheimer's disease and other dementias.

RESULTS

Women receiving tamoxifen were less likely to have a diagnosis of Alzheimer's disease documented on the MDS (odds ratio: 0.674; 95% confidence interval: 0.551-0.823), were significantly more independent in bed mobility, eating, toileting (in each case P < 0.0001), personal hygiene (P = 0.0155), dressing (P = 0.0015), transferring (P = 0.0006), locomotion (P = 0.0016), and they had better cognitive skills for daily decision-making (P < 0.0001). They were, however, 42% more likely to have a MDS diagnosis of depression (P < 0.0001). All tests of statistical significance are two-sided.

CONCLUSION

In this population, tamoxifen was associated with a higher level of independence in ADL and decision-making. While the MDS also suggested a relationship of tamoxifen with a lower prevalence of Alzheimer's disease, there seemed to be an increased prevalence of depression among treated women. The findings of this cross-sectional study could be evaluated in the randomized clinical trial that has just begun, and that will compare tamoxifen and raloxifene treatments.

Hormone replacement therapy and fractures in older adults

Estrogen deficiency in women is associated with accelerated bone loss, and estrogen replacement therapy has been proven to be effective in preventing osteoporosis and fractures in postmenopausal women. The introduction of selective estrogen receptor modulators that have an estrogen-like effect on the skeleton but have a different pattern of effects on other tissues may have an important role in the management of osteoporosis in women in the near future. In men, androgen deficiency has been shown to be associated with osteoporosis. Although androgen replacement in hypogonadal men may decrease bone resorption and increase bone mass, long-term placebo-controlled trials are needed to better define the benefits and risks of such therapy before it can be recommended. Sex hormone deficiency is linked to the development of osteoporosis in both women and men. In women, hormonal replacement by estrogen or the newly developed selective estrogen receptor modulators may prevent the development of osteoporosis and its related fractures. In men, there is early evidence that testosterone replacement therapy may enhance bone mass in hypogonadal men.

Hormonal Therapy and Chemoprevention

Hormone replacement therapy (HRT) can increase the quality as well as the length of life, but a prolonged use can also increase the risk of breast cancer. The combination of HRT and a selective estrogen receptor modulator (SERM) such as tamoxifen may retain the benefits while reducing the risks of either agent. A post hoc analysis of the Italian Tamoxifen Prevention Study showed a borderline significant reduction of breast cancer among women who were on HRT continuously and tamoxifen as compared with continuous HRT users who received placebo. Recent studies suggest that the standard dose of tamoxifen may be reduced to one-quarter (i.e., 10 mg every other day) without loss of its beneficial biological effects. Since the endometrial effect of tamoxifen seems to be both dose and time dependent, a dose reduction could substantially reduce the risk of endometrial cancer while retaining its preventive efficacy. On the other hand, the addition of HRT containing progestins could also minimize the risk of endometrial cancer associated with tamoxifen. Moreover, estrogen should reduce the incidence of vasomotor and urogenital symptoms, which are a major reason for tamoxifen withdrawal in prevention studies. Notably, in the National Surgical Adjuvant Breast Project (NSABP) P-1 trial, women ages 50 or younger had no increased incidence of adverse events, including endometrial cancer and venous thromboembolic events. One possible explanation for the lack of toxicity in premenopause is the presence of adequate circulating estrogen levels which prevent tamoxifen to act as an estrogen agonist at these target tissues. Moreover, data from the current Italian tamoxifen prevention trial indicate that the compliance was substantially higher for de novo and current HRT users as compared to women who never received HRT during the study. The combination of HRT and tamoxifen at low doses could thus reduce the risks and side effects while retaining the benefits of either agent.

Cancer in the frail patient. A coming epidemic

With the aging of the population, frailty has emerged as a new clinical entity. The frail person has exhausted any functional reserve. Current criteria for the recognition of frailty include age of over 85 years, dependence in one or more activities of daily living, three or more comorbid conditions, and the presence of one or more geriatric syndromes. It is calculated that there are approximately 6 million frail patients in the United States and approximately 400,000 of them have cancer. Management of cancer in the frail person is mainly comprised of palliation, which may include some forms of chemotherapy, such as navelbine, gemcitabine, or low-dose taxanes.

SERM Drugs for the Prevention of Osteoporosis

Although estrogens have proved useful in the prevention and treatment of osteoporosis, their side effects (for example, those on breast and endometrial cancer) are worrying to patients and physicians alike. Therefore, selective estrogen receptor modulator (SERM) drugs have been developed for use in their stead. The triphenylethylene drug tamoxifen proved to be protective against bone loss, but had side effects on uterus similar to those of natural estrogens. The tamoxifen derivative toremifene has less effect on bone. Further derivatives of tamoxifen (droloxifene, idoxifene) can be expected to act like tamoxifen when approved for clinical testing. The non-steroidal benzothiophene derivative, raloxifene, is the best SERM available thus far. It does not increase the incidence of endo-metrial cancer; in addition, like tamoxifen, it has the potential to prevent breast cancer, but has a better profile in its actions on bone (for example, it reduces the vertebral fracture rate more effectively than tamoxifen). Unlike estrogen, it decreases blood triglicerides as well as cholesterol.