Tamoxifen should be cost-effective in reducing breast cancer risk in high-risk women

Endocrine therapy for breast cancer prevention in high-risk women: clinical and economic considerations

The global burden of breast cancer highlights the need for primary prevention strategies that demonstrate both favorable clinical benefit/risk profile and good value for money. Endocrine therapy with selective estrogen-receptor modulators (SERMs) or aromatase inhibitors (AIs) has been associated with a favorable clinical benefit/risk profile in the prevention of breast cancer in women at high risk of developing the disease. The available endocrine therapy strategies differ in terms of their relative reductions of breast cancer risk, potential side effects, and upfront drug acquisition costs, among others. This review highlights the clinical trials of SERMs and AIs for the primary prevention of breast cancer, and the cost-effectiveness /cost-utility studies that have examined their "value for money" in various health care jurisdictions.

Economic evaluation of chemoprevention of breast cancer with tamoxifen and raloxifene among high-risk women in Japan

Raloxifene was approved for chemoprevention against breast cancer among high-risk women in addition to tamoxifen by the US Food and Drug Administration. This study aims to evaluate cost-effectiveness of these agents under Japan's health system. A cost-effectiveness analysis with Markov model consisting of eight health states such as healthy, invasive breast cancer, and endometrial cancer is carried out. The model incorporated the findings of National Surgical Adjuvant Breast and Bowel Project P-1 and P-2 trial, and key costs obtained from health insurance claim reviews. Favourable results, that is cost saving or cost-effective, are found by both tamoxifen and raloxifene for the introduction of chemoprevention among extremely high-risk women such as having a history of atypical hyperplasia, a history of lobular carcinoma in situ or a 5-year predicted breast cancer risk of ⩾5.01% starting at younger age, whereas unfavourable results, that is ‘cost more and gain less’ or cost-ineffective, are found for women with a 5-year predicted breast cancer risk of ⩽5.00%. Therapeutic policy switch from tamoxifen to raloxifene among postmenopausal women are implied cost-effective. Findings suggest that introduction of chemoprevention targeting extremely high-risk women in Japan can be justifiable as an efficient use of finite health-care resources, possibly contributing to cost containment.

Willingness to pay for cancer prevention

Cancer inflicts great pain, burden and cost upon American society, and preventing cancer is important but not costless. The aim of this review was to explore the upper limits that American society is paying and appears willing to pay to prevent cancer, by enforced environmental regulations and implemented clinical practice guidelines. Cost-effectiveness studies of clinical and environmental cancer-prevention policies and programmes were identified through a comprehensive literature review and confirmed to be officially sanctioned and implemented, enforced or funded. Data were collected in 2005-6 and analysed in 2007. The incremental cost-effectiveness ratios (ICERs) for clinical prevention policies ranged from under $US2000 to over $US6 000 000 per life-year saved (LYS), exceeding $US100 000 per LYS for only 11 of 101 guidelines. Median ICERs for tobacco-related ($US3978/LYS), colorectal ($US22 694/LYS) and breast ($US25 687/LYS) cancer prevention were within generally accepted ranges and tended not to vary greatly, whereas those for prostate ($US73 603/LYS) and cervical ($US125 157/LYS) cancer-prevention policies were considerably higher and varied substantially more. In contrast, both the median and range of the environmental policies were enormous, with 90% exceeding $US100 000 per LYS, and ICERs ranging from $US61 004 to over $US24 billion per LYS. Notwithstanding a relatively large and accessible literature evaluating the cost effectiveness of clinical and environmental cancer-prevention policies as well as the availability of ICERs for the policies identified in this study, the apparent willingness to pay to prevent cancer in the US still varies greatly and can be extremely high, particularly for many of the environmental cancer-prevention policies.

The benefits and costs of tamoxifen for breast cancer prevention

OBJECTIVE

To estimate the effects of key uncertainties on the effectiveness and cost-effectiveness of breast cancer prevention with tamoxifen.

METHODS

The incremental cost-effectiveness ratio of tamoxifen therapy relative to placebo was estimated using decision analysis with Markov modelling of health states, outcomes and costs for a simulated cohort of women at high risk for breast cancer. Relative effects of tamoxifen's benefits and harms were estimated from meta-analyses of randomised controlled trials. Cost estimates were based on Australian treatment patterns and costs. The main outcome measure was cost per quality-adjusted life year (QALY) gained with costs and effects discounted at a 5% annual rate.

RESULTS

Tamoxifen therapy over five years reduces the incidence of breast cancer by approximately 1.4%, which is offset by an increase in endometrial cancer of 0.7% and pulmonary embolism of 0.2%. If the reduction is permanent (preventing new breast cancers emerging over five years and no further treatment effect thereafter), the model estimates an increase in life expectancy of 0.057 QALYs and an extra cost of $2,193; or $38,271/QALY gained. A model assuming further treatment effects of tamoxifen preventing new breast cancers emerging for up to 10 years results in an incremental cost of $19,354/QALY. However, if five years of tamoxifen therapy merely delays when these breast cancers appear (such that by 10 years there is no longer a reduced incidence), the incremental cost per QALY saved is estimated to be $199,149.

CONCLUSIONS

Tamoxifen is potentially cost-effective in preventing breast cancer in women at high risk. However, its cost-effectiveness as a preventive therapy is highly sensitive to whether these cancers are permanently prevented or their clinical presentation is only delayed. Long-term follow-up in randomised controlled trials is therefore crucial in forming health policy.

Letrozole: a pharmacoeconomic review of its use in postmenopausal women with breast cancer

Letrozole (Femara), an aromatase inhibitor that blocks estrogen synthesis by inhibiting the final step of the estrogen biosynthetic pathway, is approved for use in a wide range of breast cancer settings. Randomised clinical trials in postmenopausal women with hormone-responsive early-stage breast cancer have demonstrated that, as adjuvant therapy, letrozole has greater efficacy than tamoxifen. It is also more effective than placebo as extended adjuvant therapy after completion of tamoxifen therapy in these patients. In women with hormone-responsive advanced breast cancer, letrozole is superior to tamoxifen in prolonging the time to disease progression and time to treatment failure in a first-line setting, and is at least as effective as anastrozole and more effective than megestrol for some endpoints (in one of two trials) in a second-line setting. Letrozole is generally well tolerated, and in a health-related quality-of-life analysis from a large clinical trial, patient well-being with letrozole as extended adjuvant therapy did not differ from that with placebo. Modelled analyses from the UK and the US suggest that, in postmenopausal women with hormone-receptor-positive early-stage breast cancer, letrozole is likely to be a cost-effective alternative to tamoxifen as adjuvant therapy; moreover, using letrozole as extended adjuvant therapy after tamoxifen, rather than no further treatment, is also a cost-effective treatment strategy. Sensitivity analyses have shown these results to be robust. In terms of direct healthcare costs, pharmacoeconomic models suggest that letrozole is a cost-effective alternative to tamoxifen as first-line therapy in postmenopausal women with hormone-responsive advanced breast cancer from the perspectives of the UK NHS, the Canadian and Italian public healthcare systems and the Japanese national health insurance system. Incremental costs per QALY or progression-free year gained over tamoxifen were well within the recommended limits for acceptability of new agents that are more effective and more expensive than existing therapies in the UK, Japan and Canada. Modelled analyses from the UK and Canada have also suggested that letrozole is cost effective as second-line therapy for advanced breast cancer in postmenopausal women who have disease progression following anti-estrogen therapy. In conclusion, letrozole is an effective and well tolerated treatment for postmenopausal women with early-stage or advanced hormone-responsive breast cancer. Pharmacoeconomic analyses from UK and North American perspectives support the use of letrozole in hormone-responsive early-stage breast cancer in both the adjuvant and extended adjuvant settings. In addition, other modelled analyses conducted in a variety of healthcare systems across different countries consistently suggest that letrozole is cost effective in advanced treatment settings.

Sex hormones, risk factors, and risk of estrogen receptor-positive breast cancer in older women: a long-term prospective study

OBJECTIVE

Antiestrogens reduce the risk of estrogen receptor-positive (ER+) but not ER-negative (ER-) breast cancer. Women at high risk of ER+ cancer would be the most likely to benefit from these treatments, but the best approach to predicting ER+ cancer is uncertain.

METHODS

We prospectively assessed putative risk factors for breast cancer and archived serum at -190 degrees C from a community-based cohort of 7,676 women ages > or =65 years who had no history of breast cancer. Follow-up for breast cancer over 10.5 years was 99% complete. Using a case-cohort design, we measured baseline levels of estradiol and testosterone in 196 cases of invasive ER+ cancer and 378 randomly selected controls.

RESULTS

Women whose testosterone level in highest two quintiles had a 4-fold increased risk of ER+ breast cancer (P < 0.0001). High estradiol concentration also indicated an increased risk but was not a significant predictor after adjustment for testosterone. Women with >16 years of education had a 2.1 times increased risk (P = 0.03) of ER+ cancer, but no other risk factors were significantly related to an increased risk of ER+ cancer. Women with a family history of breast cancer had a 2.9-fold increased risk of ER- cancer (P = 0.002) but no increased risk of ER+ cancer (relative hazard = 1.2, 0.8-1.8).

CONCLUSIONS

High serum testosterone and advanced education predicted ER+ breast cancer. If confirmed, high testosterone level may be more accurate than family history of breast cancer and other conventional risk factors for identifying older women who are most likely to benefit from antiestrogen chemoprevention.

Impact of uncertainty on cost-effectiveness analysis of medical strategies: The case of high-dose chemotherapy for breast cancer patients

Objectives: The object of this study was to determine, taking into account uncertainty on cost and outcome parameters, the cost-effectiveness of high-dose chemotherapy (HDC) compared with conventional chemotherapy for advanced breast cancer patients.

Methods: An analysis was conducted for 300 patients included in a randomized clinical trial designed to evaluate the benefits, in terms of disease-free survival and overall survival, of adding a single course of HDC to a four-cycle conventional-dose chemotherapy for breast cancer patients with axillary lymph node invasion. Costs were estimated from a detailed observation of physical quantities consumed, and the Kaplan–Meier method was used to evaluate mean survival times. Incremental cost-effectiveness ratios were evaluated successively considering disease-free survival and overall survival outcomes. Handling of uncertainty consisted in construction of confidence intervals for these ratios, using the truncated Fieller method.

Results: The cost per disease-free life year gained was evaluated at 13,074€, a value that seems to be acceptable to society. However, handling uncertainty shows that the upper bound of the confidence interval is around 38,000€, which is nearly three times higher. Moreover, as no difference was demonstrated in overall survival between treatments, cost-effectiveness analysis, that is a cost minimization, indicated that the intensive treatment is a dominated strategy involving an extra cost of 7,400€, for no added benefit.

Conclusions: Adding a single course of HDC led to a clinical benefit in terms of disease-free survival for an additional cost that seems to be acceptable, considering the point estimate of the ratio. However, handling uncertainty indicates a maximum ratio for which conclusions have to be discussed.

Aromatase inhibitors--socio-economical issues

Novel, third-generation aromatase inhibitors are currently implemented for treatment of postmenopausal breast cancer in the metastatic and adjuvant setting and, potentially, for breast cancer prevention. Introduction of novel therapeutic strategies to large patient groups may add significant costs to health care budgets, forcing institutions to focus entirely on costs or the cost-utility of implementing such novel strategies. Breast cancer is the most frequent cancer in the female population in western societies, and its incidence is currently increasing in other parts of the world as well. Due to the proven efficacy and limited side effects of endocrine therapy in the adjuvant setting, the indications for use have been successively broadened. Currently, the majority of postmenopausal women treated for an estrogen-receptor positive breast cancer will be offered adjuvant endocrine therapy; thus, a general change of practice may cause significant implications to healthcare costs. This may relate to direct drug costs as well as indirect costs related to prevention of side effects, like additional use of bisphosphonates to prevent enhanced bone loss. The aim of this paper is to overview these considerations and put them into perspective by simple illustrations taken from current cost estimates.

Breast carcinoma chemoprevention in the community setting

BACKGROUND

The United States Preventive Services Task Force recommends that women who are at both high risk for breast carcinoma and low risk for adverse events should receive counseling regarding tamoxifen for chemoprevention. Estimates of the risks and benefits of tamoxifen based on results from clinical trials may not reflect the real-world experience. The authors determined the prevalence of women in a community-based cohort who would meet the definition of high risk for breast carcinoma and calculated the number of women needed to screen to determine one for whom the benefits of tamoxifen would outweigh the risks. Baseline incidence also was examined for adverse health events in this community-based cohort compared with participants in the Breast Cancer Prevention Trial.

METHODS

The study participants were women ages 40-70 years (n = 6048 women) who were members of the CLUE II cohort, which started in 1989, and who responded to questionnaire surveys in 1996 and 2000.

RESULTS

Eighteen percent of all women had a 5-year risk of invasive breast carcinoma > or = 1.66%. The number of women needed to screen to find 1 woman for whom the benefits outweighed the risks of tamoxifen ranged from 26 women ages 40-49 years to 142 women ages 60-70 years. For women who had undergone a hysterectomy, the numbers needed to screen were lower. Baseline incidence rates of fracture and thromboembolic disease were higher in the community-based cohort compared with the rates observed among prevention trial participants; thus, fewer women had to be treated with tamoxifen to prevent one fracture. However, fewer women in the community also had to be treated to observe harm with a thromboembolic event.

CONCLUSIONS

Clinicians who counsel women about tamoxifen should take into consideration community-level risks and benefits.

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.

The advanced practice nursing role in a high-risk breast cancer clinic

PURPOSE/OBJECTIVES

To describe the role of an oncology nurse practitioner in a breast cancer prevention clinic.

DATA SOURCES

Published articles, abstracts, and book chapters and personal experience.

DATA SYNTHESIS

Validated risk assessment models and genetic screening can be used to assess an individual's risk for breast cancer. Lifestyle changes and medical interventions can reduce that risk.

CONCLUSIONS

Interventions for primary prevention of breast cancer soon may become one of the most effective means of reducing the incidence, morbidity, and mortality of breast cancer.

IMPLICATIONS FOR NURSING

Advanced practice nurses in the oncology setting are ideal healthcare providers to assess patients' risk of breast cancer, determine physical findings that can influence that risk, provide risk education, synthesize existing data, and make recommendations for surveillance, pharmacotherapy, lifestyle changes, and genetic counseling and testing. Limitations in the existing data in cancer prevention provide excellent opportunities for nursing research.

Efficacy and economics of hormonal therapies for advanced breast cancer

Breast cancer is a leading cause of cancer-related mortality among postmenopausal women in the US, and the economic burden of breast cancer care comprises a large percentage of the healthcare budget. Hormonal therapies have a proven place in the management of advanced breast cancer. This type of therapy is more likely to be used in older, compared with younger, women, because tumours in older women are more likely to express estrogen and progesterone receptors. While it is difficult to measure the costs of cancer care because of variation in extent and duration of treatment, treatment-related costs including costs of hormonal agents used for advanced disease account for a relatively small component of the overall costs. Newer hormonal regimens such as the new third generation nonsteroidal (letrozole, anastrozole) and steroidal (exemestane) aromatase inhibitors have shown improved clinical efficacy compared with standard regimens such as megestrol and tamoxifen in the metastatic setting in terms of objective responses or time to tumour progression. In addition the newer agents have improved toxicity profiles. Cost analyses of the newer aromatase inhibitors (anastrozole and letrozole), compared with megestrol, show an optimistic outlook for these agents. Additional work needs to be done looking at a comparison of the efficacy and costs of the aromatase inhibitors relative to the currently recommended hormonal treatments used for women with metastatic breast cancer.

Survival impact of tamoxifen use for breast cancer risk reduction: projections from a patient-specific Markov model

The authors estimate tamoxifen's impact on life expectancy among healthy women. A Markov model compared the effects of 5 years of tamoxifen on survival among 50-year-old postmenopausal women. Scenarios were explored using alternative assumptions with regard to tamoxifen's long-term effects on breast and endometrial cancer. Postmenopausal women without a uterus had substantial life expectancy gains from tamoxifen (1 to 4 months), whereas women with a uterus had such gains only if they were at a very high breast cancer risk. If tamoxifen's impact on endometrial cancer persists after treatment is discontinued, women at high risk for endometrial cancer have life expectancy losses from tamoxifen unless they are at a very high risk for breast cancer. The authors conclude that tamoxifen use among postmenopausal women is associated with substantial life expectancy gains. However, this benefit is modulated in women at increased endometrial cancer risk and depends on assumptions concerning tamoxifen's lingering effects on breast and endometrial cancer.

American Society of Clinical Oncology technology assessment of pharmacologic interventions for breast cancer risk reduction including tamoxifen, raloxifene, and aromatase inhibition

OBJECTIVE

To update an evidence-based technology assessment of chemoprevention strategies for breast cancer risk reduction. POTENTIAL INTERVENTIONS: Tamoxifen, raloxifene, aromatase inhibition, and fenretinide.

OUTCOMES

Outcomes of interest include breast cancer incidence, breast cancer-specific survival, overall survival, and net health benefit.

EVIDENCE

A comprehensive, formal literature review was conducted for relevant topics. Testimony was collected from invited experts and interested parties. The American Society of Clinical Oncology (ASCO) prescribed technology assessment procedure was followed.

VALUES

More weight was given to published randomized trials. BENEFITS/HARMS: A woman's decision regarding breast cancer risk reduction strategies is complex and will depend on the importance and weight attributed to information regarding both cancer- and noncancer-related risks and benefits.

CONCLUSIONS

For women with a defined 5-year projected breast cancer risk of > or= 1.66%, tamoxifen (at 20 mg/d for 5 years) may be offered to reduce their risk. Risk/benefit models suggest that greatest clinical benefit with least side effects is derived from use of tamoxifen in younger (premenopausal) women (who are less likely to have thromboembolic sequelae and uterine cancer), women without a uterus, and women at higher breast cancer risk. Data do not as yet suggest that tamoxifen provides an overall health benefit or increases survival. In all circumstances, tamoxifen use should be discussed as part of an informed decision-making process with careful consideration of individually calculated risks and benefits. Use of tamoxifen combined with hormone replacement therapy or use of raloxifene, any aromatase inhibitor or inactivator, or fenretinide to lower the risk of developing breast cancer is not recommended outside of a clinical trial setting. This technology assessment represents an ongoing process and recommendations will be updated in a timely matter.

VALIDATION

The conclusions were endorsed by the ASCO Health Services Research Committee and the ASCO Board of Directors.

Chemoprevention of breast cancer: implications for postmenopausal women

Estrogen administration is associated with reduction in perimenopausal symptoms and the risk for several conditions affecting postmenopausal women. As estrogen administration also increases the risk for breast cancer, a common dilemma facing many women and their physicians is whether to use estrogen replacement therapy (ERT), a selective estrogen receptor modulator (SERM) that antagonises estrogenic effects in breast tissue but retains some estrogen agonist properties in other organs, or neither. For women with average to moderate risk of breast cancer and with perimenopausal symptoms, ERT may be the best short-term choice. For very high-risk women (>1% per year) with menopausal symptoms, alternatives to ERT might be offered and tried first. A diagnosis of ductal carcinoma in situ or invasive breast cancer within the last 2 to 5 years should be considered a relative contraindication for ERT unless the tumour was estrogen receptor negative. High-risk women without menopausal symptoms are the best candidates for the only currently approved drug for breast cancer risk reduction, tamoxifen. Although the drug is approved for women with a 5-year risk of breast cancer > or = 1.7% (0.34% per year), postmenopausal women most likely to experience a favourable benefit/risk ratio are those with a Gail estimated risk of >0.5% per year without a uterus or >1% per year if they retain their uterus. Tamoxifen should not be used in women with prior history of thromboembolic or precancerous uterine conditions. Tamoxifen is often used in Europe in conjunction with transdermal ERT in hysterectomised women without obvious loss of efficacy or increased risk of thromboembolism. Raloxifene is a second generation SERM with estrogen-like agonist effects on bone but with less uterine estrogen agonist activity than tamoxifen. Raloxifene may have less potent breast antiestrogenic effects than tamoxifen, particularly in a moderate- to high-estrogen environment. Raloxifene is approved for use in reducing risk of osteoporosis, but not breast cancer. Whether it is as effective as tamoxifen in reducing breast cancer risk in postmenopausal women is the subject of a current trial. All women regardless of breast cancer risk are advised to employ nonpharmacological risk reduction measures, including normalisation of bodyweight, exercise, adequate calcium and vitamin D intake, and avoidance of smoking and alcohol. The preventive options are best weighed during an individualised consultation where a woman's menopausal symptoms and risk for breast cancer and other diseases can be examined, and the options for improving postmenopausal health can be discussed.

Outcomes of tamoxifen chemoprevention for breast cancer in very high-risk women: a cost-effectiveness analysis

PURPOSE

To estimate the effects on survival, quality-adjusted survival, and health care costs of using tamoxifen for primary prevention in subgroups of women at very high risk for breast cancer.

PATIENTS AND METHODS

A decision analysis was performed using a hypothetical cohort of women that included subgroups with atypical hyperplasia, Gail risk greater than 5, lobular carcinoma-in-situ, or two or more first-degree relatives with breast cancer. Data sources were the Breast Cancer Prevention Trial, the Surveillance, Epidemiology, and End-Results program, time trade-off preference ratings, the Group Health Cooperative of Puget Sound, and the United States Health Care Financing Administration.

RESULTS

Our model predicted that tamoxifen would prolong the average survival of cohort members initiating use at ages 35, 50, and 60 years by 70, 42, and 27 days, respectively. It would prolong survival even more for those in the higher-risk groups, especially those with atypical hyperplasia (202, 89, and 45 days). Tamoxifen use was also projected to extend quality-adjusted survival by 158, 80, and 50 days in the atypical hyperplasia group. For younger women in the highest risk groups, chemoprevention with tamoxifen was estimated to have cost savings or be cost-effective, both with and without quality adjustments.

CONCLUSION

Chemoprevention with tamoxifen may be particularly beneficial to women with atypical hyperplasia, 5-year Gail model risk greater than 5%, lobular carcinoma-in-situ, or two or more first-degree relatives with breast cancer. The benefits may be greater if tamoxifen is initiated before age 50 years rather than after and if the breast cancer risk reduction conferred by tamoxifen lasts longer than 5 years. For women with a very high risk of invasive breast cancer, chemoprevention with tamoxifen seems to be cost-effective.

Costs of treatment for elderly women with early-stage breast cancer in fee-for-service settings

PURPOSE

This study provides population-based estimates of the treatment costs for elderly women with early-stage breast cancer, with emphasis on costs of modified radical mastectomy (MRM) compared with breast-conserving surgery (BCS) and radiation therapy (RT).

PATIENTS AND METHODS

Women with breast cancer from the Surveillance, Epidemiology, and End Results cancer registries were linked with their Medicare claims, 1990 through 1998. Each claim was assigned to an initial, continuing, or terminal care phase after a cancer diagnosis. Mean monthly phase-specific costs were determined for all health care and for treatment related only to cancer. Cumulative long-term costs of care that accrue during a women's remaining lifetime were calculated by treatment group.

RESULTS

Initial care costs for the 6 months after diagnosis for women who underwent BCS with RT were approximately $450 per month higher than for women with MRM. During the continuing-care phase, costs for women undergoing BCS with RT were significantly less expensive than for MRM cases. The two groups had similar costs in the terminal-care phase. Assuming the same survival distributions, long-term costs for women undergoing BCS with RT were not statistically different than for women undergoing MRM.

CONCLUSION

Although mastectomy was less costly in the initial phase, the lifetime costs of BCS with RT and mastectomy were equivalent. Thus, women's preferences, resources to cover out-of-pocket costs, and life situations should be the major factors addressed in shared decision making about treatment options.

First do no harm: extending the debate on the provision of preventive tamoxifen

The Breast Cancer Prevention Trial (BCPT-P-1) demonstrated that tamoxifen could reduce the risk of invasive breast cancer in high-risk women by 49%, but that it could also increase the risk of endometrial cancer, vascular events and cataracts. This paper provides an estimate of the net health impacts of tamoxifen administration on high-risk Canadian women with no prior history of breast cancer. The results of the BCPT-P-1 were incorporated into the breast cancer and other modules of Statistics Canada's microsimulation POpulation HEalth Model (POHEM). While the main intervention scenario conformed as closely as possible to the eligibility criteria for tamoxifen in the BCPT-P-1 protocol, 3 additional scenarios were simulated. Predicted absolute risks of breast cancer at 5 years of 1.66%, 3.32% and 4.15% were calculated for women 35 to 70 years of age. When the BCPT-P-1 results were incorporated into the simulation model, the analysis suggests no increase in life expectancy in this risk group. Tamoxifen appeared to be beneficial for women with a 5-year predicted risk of 3.32% or greater. The results of these simulations are particularly sensitive to the reduction in mortality observed in the BCPT-P-1, as well as being sensitive to other characteristics of the simulation model. Overall, the analysis raises questions about the use of tamoxifen in otherwise healthy women at high risk of breast cancer.

Systemic therapy

Our knowledge base on systemic therapy for breast cancer continues to expand, including further information regarding hormonal prevention in high-risk women, beneficial effects of tamoxifen in noninvasive disease, an update on primary systemic therapy, and optimization of adjuvant strategies, including data on adjuvant chemoendocrine regimens. The proper evaluation of high-dose strategies has been jeopardized by a serious episode of scientific misconduct. New data are also available on palliative options, bisphosphonates, antibody therapies, and novel targets. Data continue to evolve on the role and optimal schedules of taxanes in early-stage and advanced breast cancer. These and other important recent findings are discussed in this review article.

Selective oestrogen receptor modifiers (SERMs) and breast cancer therapy

Antioestrogen therapy is currently receiving renewed interest for several reasons. Tamoxifen was introduced in the treatment of metastatic breast cancer more than three decades ago. The drug significantly reduces long term mortality and also reduces the risk of contralateral tumours when administered in early breast cancer. Five years of tamoxifen is now standard in adjuvant endocrine therapy, and the drug is currently being evaluated for breast cancer prevention. Despite this, several aspects regarding the pharmacology of the drug are still unclear, and the scientific rationale for dose selection has recently been challenged. Several novel antioestrogen compounds, called selective oestrogen receptor modifiers (SERMs), express selective oestrogen agonistic or antagonistic properties depending on the organ or test system evaluated. Some of these drugs, like raloxifene, do not seem to promote the development of endometrial cancer, although they still have selected oestrogen-like beneficial effects. This paper reviews the pharmacologic and the pharmacokinetic aspects of the different SERMs with particular emphasis on their potential use in therapy and prevention of breast cancer.

Clinical management of BRCA1- and BRCA2-associated breast cancer

The recent discovery of the breast cancer-associated genes BRCA1 and BRCA2 has changed the clinical care provided to women at high risk of breast cancer. We will review what is currently known about the clinical management of patients who bear (or are suspected of bearing) mutations in either of these two genes. The issues related to establishing a diagnosis of inherited breast cancer, deciding which women are candidates for testing, the limitations of testing, and the predictive power of these tests are addressed. The prognostic features of cancers associated with a BRCA1 and BRCA2 mutation are reviewed. Further, guidelines for prophylaxis of women with a BRCA1 or BRCA2 mutation are given and recommendations are made for the care of mutation carriers with cancer.