Cancer prevention and early detection

Advances in the area of cancer prevention and early detection are being made constantly. Basic epidemiologic research continues to provide insight into the impact of carcinogen exposure and the development of cancer. It is exciting to note that the study of Tamoxifen and Raloxifene chemoprevention trial is successfully recruiting women, including minority women, to participate. This large chemoprevention trial is providing much insight into how to recruit and retain women to take a chemoprevention agent to ultimately prevent the development of cancer. Advances also are being made in the knowledge base of how to best detect cancer in asymptomatic people. The best screening tool recommendation for the early detection of colorectal cancer remains controversial. Screening for colorectal cancer, however, is the only way to ultimately decrease the morbidity and mortality associated with the disease. Oncology nurses need to accurately risk for colorectal cancer and provide patients with the necessary information to make an informed choice about the most appropriate screening for their situation. Oncology nurses need to be familiar with new research and advances in cancer prevention and early detection so they can share information with patients and their families.

[An alternative to postmenopausal Hormone Replacement Therapy? Selective Estrogens Receptors Modulators (SERMs)]

Hormone Replacement Therapy (HRT) represents the first and probably sole therapeutically approach for prevention and treatment of medical postmenopausal disease. Nevertheless, the adverse effects and the risks HRT associated, suggested, to clinical and pharmaceutical research new pharmacological treatment options. Actually a group of compounds, SERMs (Selective Estrogen Receptor Modulators), allows a large interest. These pharmacological agents, due to their estrogen agonist/antagonist properties, are able to bind Estrogen Receptors in female target tissues (bone, brain, heart, etc) with different actions; so, by these properties, SERMs represent actually a possible alternative to HRT.

Estrogen and raloxifene activities on amyloid-beta-induced inflammatory reaction

The prevalence of Alzheimer's disease (AD) in women is double that of men. Several studies indicate that use of estrogen after menopause by women may reduce the risk of developing AD. The risk of estrogen-dependent tumors associated with estrogen replacement therapy has prompted the use of alternatives, like the SERM raloxifene, which exert estrogen agonist effects on selected target tissues. Whether SERMS provide cognitive and cardiovascular benefits comparable to those of estrogens is an active area of investigation in women's health. A chronic inflammatory process is central to the pathology of Alzheimer's disease. Using an animal model we compared the anti-inflammatory activity of orally administered estrogens (2 mg/kg) and raloxifene (3 mg/kg) in ovariectomized rats. Morphological analysis of Abeta(1-40)-induced inflammatory reaction featured adhesion and transmigration of leukocytes across the vessel wall, endothelial disruption, and platelet activation. Estrogen showed remarkable anti-inflammatory action, whereas raloxifene had no significant beneficial effect. Inhibition of the inflammatory process may contribute to the reported efficacy of estrogen in the treatment of AD.

Long-term effects of raloxifene on bone mineral density, bone turnover, and serum lipid levels in early postmenopausal women: three-year data from 2 double-blind, randomized, placebo-controlled trials

BACKGROUND

In postmenopausal women, raloxifene hydrochloride has favorable effects on bone and lipid metabolism and does not stimulate reproductive tissues. The studies reported herein evaluated the long-term (3-year) effects of raloxifene treatment on bone mineral density (BMD), serum lipid levels, and drug tolerability in healthy postmenopausal women.

METHODS

A total of 1145 healthy European and North American postmenopausal women aged 45 through 60 years were enrolled in 2 parallel, double-blind, randomized, placebo-controlled trials of identical design and randomly assigned to receive raloxifene hydrochloride, 30, 60, or 150 mg, or placebo daily; all groups received 400 to 600 mg of elemental calcium. Assessments included measurements for BMD by dual-energy x-ray absorptiometry, markers of bone turnover, and serum lipid levels.

RESULTS

Lumbar spine BMD changed from baseline to 36 months as follows: placebo (mean percentage change + SE), -1. 32% +0.22%; raloxifene, 30 mg, 0.71% +0.23%; raloxifene, 60 mg, 1. 28% +0.23%; and raloxifene, 150 mg, 1.20% +0.24%. Comparable BMD changes were observed in the hip and total body. Biochemical markers of bone turnover were suppressed by raloxifene to normal premenopausal ranges through 3 years. Serum low-density lipoprotein cholesterol was reduced 7% to 12% below baseline through 3 years. Study withdrawals due to any reason (37%) and withdrawals due to adverse events (14%) were not different among groups. The only significant adverse effect of therapy was hot flashes (25% in the 60-mg raloxifene group vs 18% in the placebo group); hot flashes were typically reported as mild and were not associated with study withdrawal (1.7% for 60-mg raloxifene vs 2.4% for placebo).

CONCLUSIONS

Raloxifene preserves BMD at important skeletal sites, lowers serum low-density lipoprotein cholesterol levels, and has a tolerability profile comparable to placebo. These results indicate a favorable benefit-risk profile of raloxifene for long-term use in healthy postmenopausal women. Arch Intern Med. 2000;160:3444-3450.

Prevention of bone loss by EM-800 and raloxifene in the ovariectomized rat

Some undesirable effects are associated with chronic estrogen and progestin administration used to prevent bone loss in postmenopausal women, thus leading to poor compliance and the need for improved therapeutic and preventive agents. We have thus studied the ability of the new antiestrogen EM-800 (SCH 57050) to prevent bone loss and lower serum cholesterol levels and compared its effects with those of raloxifene. Ovariectomized (OVX) female rats were treated by oral gavage for 37 weeks with increasing daily doses (0.01, 0.03, 0.1, 0. 3 or 1 mg/kg) of EM-800 or raloxifene. At 35 weeks after OVX, lumbar spine bone mineral density (BMD) was 19% lower than in intact animals (P<0.01), while the OVX animals given EM-800 or raloxifene had 90-93 and 85-90%, respectively, of the BMD values observed in intact rats. Similar effects were observed on femoral BMD. Bone histomorphometry measurements were performed on proximal tibia. At the 0.01 mg/kg dose, EM-800 prevented the effect of OVX on TBV by 34% (P<0.01), while raloxifene had no detectable effect. Treatment with 1 mg/kg EM-800 and raloxifene resulted in, respectively, 68% (P<0.01) and 64% (P<0.01) prevention of the OVX-induced decrease in TBV. In addition, the administration of 0.01 and 0.03 mg/kg EM-800 caused, respectively, 54% (P<0.01) and 56% (P<0.01) inhibitions of serum cholesterol levels, while raloxifene administered at the same doses caused, respectively, 24% (P<0.01) and 41% (P<0.01) decreases of the value of the same parameter. At the highest doses used (0.1-1 mg/kg), both compounds lowered serum cholesterol levels by approximately 65% (P<0.01). No stimulatory effect of EM-800 was observed on the endometrial epithelial cells at doses up to 1 mg/kg, while hypertrophy of uterine epithelium was observed with raloxifene. EM-800 and raloxifene achieve the same degree of effectiveness on bone and serum cholesterol at higher doses, but EM-800 is at least three to ten times more potent than raloxifene at lower concentrations and has no stimulatory effect on uterine epithelium. The present data show the potent effect of EM-800 preventing bone loss and lower serum cholesterol levels without the negative effect on the endometrium, thus suggesting the particular interest of this new fully tissue-specific selective estrogen receptor modulator.

[Raloxifene]

Raloxifene belongs to the group of selective estrogen receptor modulators (SERMs). It interacts with both estrogen receptor alpha and beta, but the postreceptor responses differ from those of estrogens. Raloxifene exerts tissue specific responses that differ from estrogens. The drug increases bone mass by 2-3% and inhibits the risk of subsequent vertebral fractures by 30-50%. Raloxifene reduces the risk of breast cancer by 76% after treatment for four years and builds an atrophic endometrium without any bleedings. Furthermore, the risk of endometrial cancer is not increased. The drug exerts positive effects on plasma lipids, but the effects of these changes on subsequent risk of myocardial infarction and cardiovascular death are still unknown. The main side effects are leg cramps, increases in hot flushes and peripheral oedema. Like estrogen, the drug increases the relative risk for venous thrombosis by a factor three.

The effect of raloxifene on coronary arteries in aged ovariectomized ewes

BACKGROUND

Ovariectomized sheep are a useful model of postmenopausal osteoporosis and other postmenopausal conditions. Estrogen may have a protective effect on the coronary arteries in postmenopausal women. The effects of raloxifene, a selective estrogen receptor modulator, on coronary arteries in aged ovariectomized ewes was investigated.

METHODS AND RESULTS

Forty eight aged ewes were randomly assigned to undergo sham surgery (Sham, n = 7), ovariectomy (OVX, n = 10), ovariectomy with estradiol supplementation (OVXE, n = 8), ovariectomy with raloxifene supplementation, 0.02 mg/kg per day (RAL1, n = 10), or ovariectomy with raloxifene supplementation, 0.10 mg/kg per day (RAL2, n = 13). Contrast coronary angiography was performed 6 months after intervention. Diameters of the right main and left anterior descending coronary arteries in the RAL1, RAL2 and Sham groups were not different from each other, but were significantly greater than the OVX and OVXE groups. Intracoronary nitroglycerin did not affect the relationships of the diameters in any group. There were no differences in vascular remodeling between the groups.

CONCLUSIONS

The results indicate that raloxifene in this sheep model allows greater dilation of coronary arteries than estrogen. Raloxifene may provide a significant protective functional effect on coronary arteries in postmenopausal heart disease.

Alendronic acid in primary prevention: new indication. No reduction in fracture risk

(1) Alendronic acid at a dose of 5 mg/day is now licensed in France for primary prevention of postmenopausal fractures. (2) The clinical file is relatively bulky and methodologically adequate, but there are no comparisons with combined hormone replacement therapy or with raloxifen. (3) Three trials have shown that 5 mg/day alendronic acid slows postmenopausal bone loss. However, this effect disappears on treatment cessation, and mineral bone density is only one risk factor for postmenopausal fractures. (4) A placebo-controlled trial of primary prevention involving more than 4,000 patients showed no reduction in the risk of fracture after 4 years of treatment with alendronic acid (5 mg/day for 2 years, then 10 mg/day). (5) Alendronic acid increases the risk of oesophageal ulceration, necessitating strict precautions during ingestion.

Effects of high dose raloxifene in selected patients with advanced breast carcinoma

BACKGROUND

An earlier trial of raloxifene, conducted in women with metastatic breast carcinoma who initially had responded to tamoxifen and subsequently developed disease progression, suggested no antitumor activity for raloxifene in tamoxifen-refractory disease. However, preclinical studies and preliminary clinical data in healthy women suggest that raloxifene antagonizes growth of estrogen-dependent neoplasia.

METHODS

Raloxifene HCl 150 mg twice daily was given to 22 postmenopausal women with metastatic (American Joint Committee on Cancer Stage IV) or locoregionally recurrent, initially estrogen receptor positive breast carcinoma. Prior systemic treatment of metastatic disease was not allowed. Prior adjuvant chemotherapy or hormonal therapy was required to have been completed at least 1 year before study entry. Tumor response was evaluated every other month either radiographically or by physical examination. Evaluable disease was defined as bidimensionally measurable lesions.

RESULTS

Twenty-one patients were eligible for efficacy analysis; 6 had been treated previously with tamoxifen. There were no complete tumor responses. Four patients (19%; 95% confidence interval [95% CI], 2.2%, 36%) had partial tumor responses lasting 6.3, 17.5, 23.9, and 28.1 months, respectively. Prolonged stable disease (i.e., tumor size stable for > or = 6 months) was observed in 3 patients (14%; 95% CI, 0.0%, 29%) and lasted 7.9, 12.2, and 25.1 months, respectively. Combining partial responses and prolonged stable disease yielded an overall clinical benefit rate of 33% (95% CI, 13%, 53%). Adverse events generally were consistent with the disease state; there were no serious adverse events or laboratory changes believed to be therapy-related.

CONCLUSIONS

Raloxifene HCl, 150 mg, administered twice daily was safe, well tolerated, and modestly effective in highly selected postmenopausal women with advanced breast carcinoma. Further study of high dose raloxifene as monotherapy for advanced breast carcinoma most likely is unwarranted.

Coronary and uterine vascular responses to raloxifene in the sheep

OBJECTIVE

We sought to determine whether raloxifene increases coronary and uterine blood flow in ovariectomized ewes.

STUDY DESIGN

Twelve ewes were chronically instrumented for measurement of mean arterial pressure, heart rate, cardiac output, coronary blood flow, and uterine blood flow. Sheep received 17beta-estradiol, Estrace, raloxifene, or KY Jelly vehicle on separate days.

RESULTS

17beta-Estradiol increased uterine blood flow from 21 +/- 3 to 254 +/- 36 mL/min and coronary blood flow by 21% +/- 2% within 2 hours. Estrace increased uterine blood flow from 30 +/- 7 to 260 +/- 62 mL/min and coronary blood flow by 8% +/- 4% within 3 hours. Raloxifene increased uterine blood flow from 20 +/- 3 mL/min to 220 +/- 53 mL/min by 6 hours and coronary blood flow by 22% +/- 5% within 24 hours. To determine whether hemodynamic responses were mediated by nitric oxide, L -nitroarginine methyl ester was administered and produced an approximate 50% decrease in uterine blood flow for all 3 compounds. L -Nitroarginine methyl ester attenuated increases in coronary blood flow induced by 17beta-estradiol, Estrace, and raloxifene.

CONCLUSION

Raloxifene has significant coronary and uterine vascular effects in the ovariectomized ewe. The coronary and uterine responses are partially mediated by nitric oxide.

[Raloxifene (Celvista, Evista)]

The prevention of osteoporotic fractures in post-menopausal women must be viewed in the framework of the treatment of menopause. SERMs ("Selective Estrogen Receptor Modulators") derivative from steroid hormones have estrogenic and antiestrogenic properties according to the substance and the target tissue. Raloxifene is a second generation SERM. It increases bone mass by 1 to 3% according to the measured site and, after 3 years of therapy at the dose of 60 mg per day, it reduces the incidence of vertebral fractures by 30 to 50% if patients have or do not have vertebral fractures before therapy. This drug is approved for the prevention of vertebral fractures in post-menopausal women at increased risk of fractures. A significant reduction in the incidence of hip fractures has not been demonstrated. Raloxifene exerts favorable effects on cardiovascular risk factors but one has to wait for the results of controlled prospective trials before concluding that raloxifene reduces the risk of atherogeniec disease. Preliminary results indicate a substantial reduction of the risk of invasive breast cancer, still to be confirmed. The incidence of vaginal bleeding does not differ from placebo as raloxifene does not stimulate endometrial proliferation. The most serious adverse event, although infrequent, consists in an increase of the relative risk of thromboembolic disease by 3.1 as compared to placebo. Longer term studies are necessary to compare raloxifene with the estrogen replacement therapy and to determine the extra-bone effects.

Raloxifene reduces atherosclerosis: studies of optimized raloxifene doses in ovariectomized, cholesterol-fed rabbits

OBJECTIVE

We have previously shown that raloxifene, a selective oestrogen receptor modulator, 35 mg/day inhibits atherosclerosis in ovariectomized, cholesterol-fed rabbits. This effect was only partial as compared to 17beta-oestradiol 4 mg/day; however, plasma raloxifene concentrations were low relative to those obtained in raloxifene-treated women. We therefore investigate the effects of raloxifene at higher doses.

DESIGN

The study on atherosclerosis in ovariectomized, cholesterol-fed rabbits (n = 80) compared raloxifene 70 mg/day and 210 mg/day to 17beta-oestradiol 4 mg/day and placebo.

RESULTS

After 48 weeks of therapy, the aortic cholesterol content in the 70 mg/day and 210 mg/day raloxifene treatment groups were 471 +/- 56 nmol/mg protein and 456 +/- 56 nmol/mg protein, respectively. This was significantly less than in the placebo group (654 +/- 69 nmol/mg protein; P < 0.05). In the oestrogen-treated group, the aortic cholesterol content was 357 +/- 62 nmol/mg protein (P < 0.01 as compared to placebo). Differences in serum lipids between the treatment groups could only partly explain the effect on aortic cholesterol content, indicating that additional anti-atherogenic mechanisms may contribute to the decrease in aortic atherosclerosis. This anti-atherosclerotic activity of raloxifene was observed at plasma concentrations comparable to those in postmenopausal women during raloxifene treatment.

CONCLUSIONS

We conclude that clinically relevant raloxifene treatment inhibits aortic atherosclerosis in ovariectomized, cholesterol-fed rabbits.

Both raloxifene and estrogen reduce major cardiovascular risk factors in healthy postmenopausal women: A 2-year, placebo-controlled study

Currently raloxifene, a selective estrogen receptor modulator, is being investigated as a potential alternative for postmenopausal hormone replacement to prevent osteoporosis and cardiovascular disease. We compared the 2-year effects of raloxifene on a wide range of cardiovascular risk factors with those of placebo and conjugated equine estrogens (CEEs). Analyses were based on 56 hysterectomized but otherwise healthy postmenopausal women aged 54. 8+/-3.5 (mean+/-SD) years who entered this double-blind study and who were randomly assigned to raloxifene hydrochloride 60 mg/d (n=15) or 150 mg/d (n=13), placebo (n=13), or CEEs 0.625 mg/d (n=15). At baseline and after 6, 12, and 24 months of treatment, we assessed serum lipids, blood pressure, glucose metabolism, C-reactive protein, and various hemostatic parameters. Compared with placebo, both raloxifene and CEEs lowered the level of low density lipoprotein cholesterol by 0.53 to 0.79 mmol/L (all P<0.04) and lowered, at 24 months, the level of fibrinogen by 0.71 to 0.86 g/L (all P<0.05). The effects of raloxifene and CEEs did not differ significantly. In contrast to raloxifene, from 6 months on CEEs increased high density lipoprotein cholesterol by 0.25 to 0.29 mmol/L and reduced plasminogen activator inhibitor-1 antigen by 30.6 to 48.6 ng/mL (all P<0.02 versus both placebo and raloxifene). CEEs transiently increased C-reactive protein by 1.0 mg/L at 6 months (P<0.05 versus placebo) and prothrombin-derived fragment F1+2 by 0. 79 nmol/L at 12 months (P<0.001 versus placebo). Finally, from 12 months on, CEEs increased triglycerides by 0.33 to 0.56 mmol/L (all P<0.05 versus both placebo and raloxifene). Our findings suggest that in healthy postmenopausal women, raloxifene and estrogen monotherapy have similar beneficial effects on low density lipoprotein cholesterol and fibrinogen levels. These treatments differ, however, in their effects on high density lipoprotein cholesterol, triglycerides, and plasminogen activator inhibitor-1 and possibly in their effects on prothrombin fragment F1+2 and C-reactive protein.

An expanding landscape. Osteoporosis. Treatment options today

Choices for osteoporosis therapy have expanded within the past 5 years. This article provides an overview of currently available therapy options. Exogenous estrogen can prevent and treat osteoporosis and is available in several delivery routes. Calcitonin is also designed to reduce bone loss in osteoporosis. Bisphosphonates such as alendronate prevent bone resorption by inhibiting osteoclasts and causing increased osteoclast cell death. Raloxifene is a selective estrogen receptor modulator and is the newest osteoporosis medication on the market. It may also have beneficial effects on breast cancer risk. All postmenopausal women should obtain 1,000 mg to 1,500 mg of calcium and 400 IU to 800 IU of vitamin D every day--regardless of any prescription therapy regimen for osteoporosis. They should also perform weight-bearing exercise, such as walking, for 20 to 30 minutes every day or for 1 hour three times a week.