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

Hormone therapy in women with benign breast disease - What little is known and suggestions for clinical implementation

Benign breast disease encompasses a spectrum of lesions within the breast. While some lesions pose no increase in risk, others may elevate the likelihood of developing breast cancer by four- to five-fold. This necessitates a personalized approach to screening and lifestyle optimization for women. The menopausal transition is a critical time for the development of benign breast lesions. Increased detection can be attributed to the heightened precision and utilization of screening mammography, with or without the use of supplemental imaging. While it is widely acknowledged that combined hormone therapy involving estrogen and progesterone may elevate the risk of breast cancer, data from the Women's Health Initiative (WHI) indicates that estrogen-alone therapies may actually reduce the overall risk of cancer. Despite this general understanding, there is a notable gap in information regarding the impact of hormone therapy on the risk profile of women with specific benign breast lesions. This review comprehensively examines various benign breast lesions, delving into their pathophysiology and management. The goal is to enhance our understanding of when and how to judiciously prescribe hormone therapy, particularly in the context of specific benign breast conditions. By bridging this knowledge gap, the review provides valuable insights into optimizing healthcare strategies for women with benign breast disease, and offers a foundation for more informed decision-making regarding hormone therapy.

Long-term breast cancer incidence trends by mammography, obesity, and menopausal hormone therapy

PURPOSE

Over the past half century, the annual age-adjusted breast cancer incidence in the USA has fluctuated, potentially influenced by changes in mammography screening, obesity, and menopausal hormone therapy. As the relative contributions of these factors on breast cancer incidence have not been resolved, we assembled reliable sources of year-to-year changes in mammography, obesity, and hormone therapy to graphically display their relationship to breast cancer incidence through 50 years.

METHODS

Year-to-year trends were assembled: for mammography from the Center for Disease Control National Health Interviews; for hormone therapy from the Collaborative Group on Hormonal Factors in Breast Cancer report; for obesity from the NCD (Non-Communicable Diseases) Risk Factor Collaboration; and for breast cancer for US women 50-64 years of age from Surveillance, Epidemiology, and End Results (SEER) registry findings.

RESULTS

Increases in age-adjusted breast cancer incidence trend from about 1982 to 2002 track both mammography and hormone therapy use but not obesity. However, the sudden decrease in breast cancer incidence in 2003, subsequently sustained at a lower incidence level, only tracks the parallel reduction in hormone therapy use.

CONCLUSION

The sustained reduction in hormone therapy use from 2003 provides a plausible explanation for most of the lower breast cancer incidence seen in US postmenopausal women during the last two decades. The strong observational study obesity association with higher breast cancer risk is not reflected in breast cancer incidence trends.

Acceptability of an mHealth breast cancer risk-reduction intervention promoting risk assessment, education, and discussion of risk in the primary care setting

BACKGROUND

Breast cancer risk assessment tools and risk reduction strategies have advanced significantly over the past few decades but are underutilized in practice, due in part to limited acceptability by patients and physicians. We implemented a tablet-based Breast Cancer Risk Education Intervention (BreastCARE) tailored towards increasing patients' knowledge about their individual risk of developing breast cancer, increasing patient-physician discussion of breast cancer risk reduction practices, and increasing participation in recommended screening.

METHODS

We surveyed patients and physicians who received the BreastCARE intervention and analyzed their satisfaction and acceptability of the intervention. We compared patient satisfaction measures by race/ethnicity and used multivariable logistic regression models to examine the effect of race/ethnicity on measures of patient satisfaction with the tablet-based risk assessment and with the breast cancer risk report. We also compared measures of physician satisfaction by resident vs. attending/NP status. Finally, we identified patients' and physicians' suggestions for implementation.

RESULTS

Overall, both patients and physicians were highly satisfied with BreastCARE, with some variation by patient race/ethnicity and breast cancer risk status. The risk assessment tool and accompanying risk report helped transmit complex information in an efficient way.

CONCLUSIONS

Patient self-administered risk assessment with a health education component at the point of care is acceptable for both patients and physicians, and represents a novel approach to facilitating health promotion. This risk assessment tool should be made routine in primary care accompanied by results that are easy for the patient to understand and actionable for the clinician.

Risk for breast cancer and management of unaffected individuals with non-BRCA hereditary breast cancer

About 5%-10% of breast cancer is hereditary with BRCA1 and BRCA2 being the most common genes associated with hereditary breast cancer (HBC). Several additional genes have recently been associated with HBC. These genes can be classified as highly or moderately penetrant genes with lifetime risk >30% or 17%-30%, respectively. Highly penetrant genes associated with HBC include TP53, PTEN, CDH1, STK11, and PALB2. While, moderately penetrant genes include CHEK2, ATM, BARD1, BRIP1, NBN, NF1, RAD51D, and MSH6. Breast cancer risk and recommendations for screening and risk-reduction vary by gene. In general, screening breast MRI is recommended for women at >20% lifetime risk, which includes women with mutations in highly penetrant genes and the majority (but not all) moderately penetrant genes. Consideration of chemoprevention is recommended for women with mutations in high and moderately penetrant genes. Risk-reducing mastectomy does reduce the risk of breast cancer to the greatest extent and can be considered for women with highly penetrant genes. However, this procedure is associated with significant morbidities that should be considered, especially given the benefit of using screening breast MRI for high-risk women. BSO is only recommended for women with mutations in genes associate with increased risk for ovarian cancer and not as a breast cancer risk-reducing strategy. As more women undergo testing, additional genes may be identified and risk estimates for current genes and management recommendations may be modified.

Dietary Modification and Breast Cancer Mortality: Long-Term Follow-Up of the Women's Health Initiative Randomized Trial

PURPOSE

Observational studies of dietary fat intake and breast cancer have reported inconsistent findings. This topic was addressed in additional analyses of the Women's Health Initiative (WHI) Dietary Modification (DM) clinical trial that evaluated a low-fat dietary pattern influence on breast cancer incidence.

METHODS

In the WHI DM trial, 48,835 postmenopausal women, ages 50-79 years, with no prior breast cancer, and a dietary fat intake of ≥ 32% of energy were randomly assigned at 40 US centers to a usual diet comparison group (60%) or dietary intervention group (40%). The goals were to reduce fat intake to 20% of energy and increase vegetable, fruit, and grain intake. Breast cancers were confirmed after central medical record review and serial National Death Index linkages to enhance mortality findings.

RESULTS

During 8.5 years of dietary intervention, breast cancer incidence and deaths as a result of breast cancer were nonsignificantly lower in the intervention group, while deaths after breast cancer were statistically significantly lower both during intervention and through a 16.1-year (median) follow-up. Now, after a long-term, cumulative 19.6-year (median) follow-up, the significant reduction in deaths after breast cancer persists (359 [0.12%] v 652 [0.14%] deaths; hazard ratio [HR], 0.85; 95% CI, 0.74 to 0.96; P = .01), and a statistically significant reduction in deaths as a result of breast cancer (breast cancer followed by death attributed to the breast cancer) emerged (132 [0.037%, annualized risk] v 251 [0.047%] deaths, respectively; HR, 0.79; 95% CI, 0.64 to 0.97; P = .02).

CONCLUSION

Adoption of a low-fat dietary pattern associated with increased vegetable, fruit, and grain intake, demonstrably achievable by many, may reduce the risk of death as a result of breast cancer in postmenopausal women.

Patient and provider factors associated with the noninitiation of tamoxifen for young women at high‐risk for the development of breast cancer

We sought to identify factors associated with disparities in tamoxifen utilization among young patients at high-risk for developing breast cancer. We identified 67 premenopausal, high-risk women age 35-45, without surgical prophylaxis, who did not initiate tamoxifen. Factors associated with noninitiation were examined. About 37% of patients had no documented provider-based discussion regarding initiation. Type of high-risk diagnosis was the only factor associated with a provider-based discussion (P = .03). For patients offered tamoxifen, primary reasons for noninitiation were perceived minimal benefit (66.7%), fertility concerns (16.7%), and concerns about side effects (7.1%). Implementation of comprehensive educational strategies regarding the benefits of tamoxifen should be facilitated to improve initiation among young high-risk patients.

Use of Endocrine Therapy for Breast Cancer Risk Reduction: ASCO Clinical Practice Guideline Update

PURPOSE

To update the ASCO guideline on pharmacologic interventions for breast cancer risk reduction and provide guidance on clinical issues that arise when deciding to use endocrine therapy for breast cancer risk reduction.

METHODS

An Expert Panel conducted targeted systematic literature reviews to identify new studies.

RESULTS

A randomized clinical trial that evaluated the use of anastrozole for reduction of estrogen receptor–positive breast cancers in postmenopausal women at increased risk of developing breast cancer provided the predominant basis for the update.

UPDATED RECOMMENDATIONS

In postmenopausal women at increased risk, the choice of endocrine therapy now includes anastrozole (1 mg/day) in addition to exemestane (25 mg/day), raloxifene (60 mg/day), or tamoxifen (20 mg/day). The decision regarding choice of endocrine therapy should take into consideration age, baseline comorbidities, and adverse effect profiles. Clinicians should not prescribe anastrozole, exemestane, or raloxifene for breast cancer risk reduction to premenopausal women. Tamoxifen 20 mg/day for 5 years is still considered standard of care for risk reduction in premenopausal women who are at least 35 years old and have completed childbearing. Data on low-dose tamoxifen as an alternative to the standard dose for both pre- and postmenopausal women with intraepithelial neoplasia are discussed in the Clinical Considerations section of this article. Additional information is available at www.asco.org/breast-cancer-guidelines .

An Intervention Tool to Increase Patient-Physician Discussion of Lifestyle Risk Factors for Breast Cancer

Background: Risk assessment and discussion of lifestyle in primary care are crucial elements of breast cancer prevention and risk reduction. Our objective was to evaluate the impact of a breast cancer risk assessment and education tool on patient-physician discussion of behaviors and breast cancer risk. Materials and Methods: We conducted a randomized controlled trial with an ethnically and linguistically diverse sample of women, ages 40-74, from two primary care practices. Intervention participants completed a tablet computer-based Breast Cancer Risk Assessment and Education (BreastCARE) intervention in the waiting room before a scheduled visit. Both patients and physicians received an individualized risk report to discuss during the visit. Control patients underwent usual care. Telephone surveys assessed patient-physician discussion of weight, exercise, and alcohol use 1 week following the visit. Results: Among the 1235 participants, 27.7% (161/580) intervention and 22.3% (146/655) usual-care patients were high risk for breast cancer. Adjusting for clustering by physician, the intervention increased discussions of regular exercise (odds ratios [OR] = 1.94, 1.50-2.51) and weight (OR = 1.56, 1.23-1.96). There was no effect of the intervention on discussion of alcohol. Women with some college education were more likely to discuss their weight than those with high school education or less (OR = 1.75, 1.03-2.96). Similarly, non-English speakers were more likely to discuss their weight compared with English speakers (OR = 2.33, 1.04-5.22). Conclusions: BreastCARE is a feasible risk assessment tool that can successfully promote discussions about modifiable breast cancer risk factors between patients and primary care physicians.

Risk-reducing medications for primary breast cancer: a network meta-analysis

BACKGROUND

Breast cancer is the most frequently occurring malignancy and the second cause of death for cancer in women. Cancer prevention agents (CPAs) are a promising approach to reduce the burden of breast cancer. Currently, two main types of CPAs are available: selective estrogen receptor modulators (SERMs, such as tamoxifen and raloxifene) and aromatase inhibitors (AIs, such as exemestane and anastrozole).

OBJECTIVES

To assess the efficacy and acceptability of single CPAs for the prevention of primary breast cancer, in unaffected women, at an above-average risk of developing breast cancer.Using a network meta-analysis, to rank single CPAs, based on their efficacy and acceptability (an endpoint that is defined as the inverse of CPA-related toxicity).

SEARCH METHODS

We searched the Cochrane Breast Cancer Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, World Health Organization's International Clinical Trials Registry Platform (WHO ICTRP), and ClinicalTrials.gov on 17 August 2018. We handsearched reference lists to identify additional relevant studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that enrolled women without a personal history of breast cancer but with an above-average risk of developing a tumor. Women had to be treated with a CPA and followed up to record the occurrence of breast cancer and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and conducted risk of bias assessments of the included studies, and assessed the certainty of the evidence using GRADE. Outcome data included incidence of breast carcinoma (both invasive and in situ carcinoma) and adverse events (both overall and severe toxicity). We performed a conventional meta-analysis (for direct comparisons of a single CPA with placebo or a different CPA) and network meta-analysis (for indirect comparisons).

MAIN RESULTS

We included six studies enrolling 50,927 women randomized to receive one CPA (SERMs: tamoxifen or raloxifene, or AIs: exemestane or anastrozole) or placebo. Three studies compared tamoxifen and placebo, two studies compared AIs (exemestane or anastrozole) versus placebo, and one study compared tamoxifen versus raloxifene. The risk of bias was low for all RCTs.For the tamoxifen versus placebo comparison, tamoxifen likely resulted in a lower risk of developing breast cancer compared to placebo (risk ratio (RR) 0.68, 95% confidence interval (CI) 0.62 to 0.76; 3 studies, 22,832 women; moderate-certainty evidence). In terms of adverse events, tamoxifen likely increased the risk of severe toxicity compared to placebo (RR 1.28, 95% CI 1.12 to 1.47; 2 studies, 20,361 women; moderate-certainty evidence). In particular, women randomized to receive tamoxifen experienced a higher incidence of both endometrial carcinoma (RR 2.26, 95% CI 1.52 to 3.38; high-certainty evidence) and thromboembolism (RR 2.10, 95% CI 1.14 to 3.89; high-certainty evidence) compared to women who received placebo.For the AIs versus placebo comparison, AIs (exemestane or anastrozole) reduced the risk of breast cancer by 53% (RR 0.47, 95% CI 0.35 to 0.63; 2 studies, 8424 women; high-certainty evidence). In terms of adverse events, AIs increased the risk of severe toxicity by 18% (RR 1.18, 95% CI 1.09 to 1.28; 2 studies, 8352 women; high-certainty evidence). These differences were sustained especially by endocrine (e.g. hot flashes), gastrointestinal (e.g. diarrhea), and musculoskeletal (e.g. arthralgia) adverse events, while there were no differences in endometrial cancer or thromboembolism rates between AIs and placebo.For the tamoxifen versus raloxifene comparison, raloxifene probably performed worse than tamoxifen in terms of breast cancer incidence reduction (RR 1.25, 95% CI 1.09 to 1.43; 1 study, 19,490 women; moderate-certainty evidence), but its use was associated with lower toxicity rates (RR 0.87, 95% CI 0.80 to 0.95; 1 study, 19,490 women; moderate-certainty evidence), particularly relating to incidence of endometrial cancer and thromboembolism.An indirect comparison of treatment effects allowed us to compare the SERMs and AIs in this review. In terms of efficacy, AIs (exemestane or anastrozole) may have reduced breast cancer incidence slightly compared to tamoxifen (RR 0.67, 95% CI 0.46 to 0.98; 5 RCTs, 31,256 women); however, the certainty of evidence was low. A lack of model convergence did not allow us to analyze toxicity data.

AUTHORS' CONCLUSIONS

For women with an above-average risk of developing breast cancer, CPAs can reduce the incidence of this disease. AIs appear to be more effective than SERMs (tamoxifen) in reducing the risk of developing breast cancer. AIs are not associated with an increased risk of endometrial cancer and thromboembolic events. However, long-term data on toxicities from tamoxifen are available while the follow-up toxicity data on unaffected women taking AIs is relatively short. Additional data from direct comparisons are needed to fully address the issues of breast cancer prevention by risk-reducing medications, with special regards to acceptability (i.e. the benefit/harm ratio).

Augmented expression of Ki-67 is correlated with clinicopathological characteristics and prognosis for lung cancer patients: an up-dated systematic review and meta-analysis with 108 studies and 14,732 patients

Background

Lung cancer ranks as the leading cause of cancer-related deaths worldwide and we performed this meta-analysis to investigate eligible studies and determine the prognostic effect of Ki-67.

Methods

In total, 108 studies in 95 articles with 14,732 patients were found to be eligible, of which 96 studies reported on overall survival (OS) and 19 studies reported on disease-free survival (DFS) with relation to Ki-67 expression in lung cancer patients.

Results

The pooled hazard ratio (HR) indicated that a high Ki-67 level could be a valuable prognostic factor for lung cancer (HR = 1.122 for OS, P < 0.001 and HR = 1.894 for DFS, P < 0.001). Subsequently, the results revealed that a high Ki-67 level was significantly associated with clinical parameters of lung cancer including age (odd ratio, OR = 1.246 for older patients, P = 0.018), gender (OR = 1.874 for males, P < 0.001) and smoking status (OR = 3.087 for smokers, P < 0.001). Additionally, significant positive correlations were found between Ki-67 overexpression and poorer differentiation (OR = 1.993, P = 0.003), larger tumor size (OR = 1.436, P = 0.003), and higher pathologic stages (OR = 1.867 for III-IV, P < 0.001). Furthermore, high expression of Ki-67 was found to be a valuable predictive factor for lymph node metastasis positive (OR = 1.653, P < 0.001) and advanced TNM stages (OR = 1.497 for stage III-IV, P = 0.024). Finally, no publication bias was detected in any of the analyses.

Conclusions

This study highlights that the high expression of Ki-67 is clinically relevant in terms of the prognostic and clinicopathological characteristics for lung cancer. Nevertheless, more prospective well-designed studies are warranted to validate these findings.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0843-7) contains supplementary material, which is available to authorized users.

Towards Prevention of Breast Cancer: What Are the Clinical Challenges?

The dramatic increase in breast cancer incidence compels a paradigm shift in our preventive efforts. There are several barriers to overcome before prevention becomes an established part of breast cancer management. The objective of this review is to identify the clinical challenges for improved breast cancer prevention and discuss current knowledge on breast cancer risk assessment methods, risk communication, ethics, and interventional efforts with the aim of covering the aspects relevant for a breast cancer prevention trial. Herein, the following five areas are discussed: (i) Adequate tools for identification of women at high risk of breast cancer suggestively entitled Prevent! Online. (ii) Consensus on the definition of high risk, which is regarded as mandatory for all risk communication and potential prophylactic interventions. (iii) Risk perception and communication regarding risk information. (iv) Potential ethical concerns relevant for future breast cancer prevention programs. (v) Risk-reducing programs involving multileveled prevention depending on identified risk. Taken together, devoted efforts from both policy makers and health care providers are warranted to improve risk assessment and risk counseling in women at risk for breast cancer to optimize the prevention of breast cancer. Cancer Prev Res; 11(5); 255-64. ©2018 AACR.

Personalized prevention in high risk individuals: Managing hormones and beyond

Increasing numbers of women are being identified at 'high-risk' of breast cancer, defined by The National Institute of Health and Care Excellence (NICE) as a 10-year risk of ≥8%. Classically women have been so identified through family history based risk algorithms or genetic testing of high-risk genes. Recent research has shown that assessment of mammographic density and single nucleotide polymorphisms (SNPs), when combined with established risk factors, trebles the number of women reaching the high risk threshold. The options for risk reduction in such women include endocrine chemoprevention with the selective estrogen receptor modulators tamoxifen and raloxifene or the aromatase inhibitors anastrozole or exemestane. NICE recommends offering anastrozole to postmenopausal women at high-risk of breast cancer as cost effectiveness analysis showed this to be cost saving to the National Health Service. Overall uptake to chemoprevention has been disappointingly low but this may improve with the improved efficacy of aromatase inhibitors, particularly the lack of toxicity to the endometrium and thrombogenic risks. Novel approaches to chemoprevention under investigation include lower dose and topical tamoxifen, denosumab, anti-progestins and metformin. Although oophorectomy is usually only recommended to women at increased risk of ovarian cancer it has been shown in numerous studies to reduce breast cancer risks in the general population and in those with mutations in BRCA1/2. However, recent evidence from studies that have confined analysis to true prospective follow up have cast doubt on the efficacy of oophorectomy to reduce breast cancer risk in BRCA1 mutation carriers, at least in the short-term.

Preventing invasive breast cancer using endocrine therapy

Developments in breast cancer treatment have resulted in reduction in breast cancer mortality in the developed world. However incidence continues to rise and greater use of preventive interventions including the use of therapeutic agents is needed to control this burden. High quality evidence from 9 major trials involving more than 83000 participants shows that selective oestrogen receptor modulators (SERMs) reduce breast cancer incidence by 38%. Combined results from 2 large trials with 8424 participants show that aromatase inhibitors (AIs) reduce breast cancer incidence by 53%. These benefits are restricted to prevention of ER positive breast cancers. Restricting preventive therapy to high-risk women improves the benefit-harm balance and many guidelines now encourage healthcare professionals to discuss preventive therapy in these women. Further research is needed to improve our risk-prediction models for the identification of high risk women for preventive therapy with greater accuracy and to develop surrogate biomarkers of response. Long-term follow-up of the IBIS-I trial has provided valuable insights into the durability of benefits from preventive therapy, and underscores the need for such follow up to fully evaluate other agents. Full utilisation of preventive therapy also requires greater knowledge and awareness among both doctors and patients about benefits, harms and risk factors. Healthcare professionals should routinely discuss preventive therapy with women at high-risk of breast cancer.

What Matters to Women When Making Decisions About Breast Cancer Chemoprevention?

PURPOSE

Despite the effectiveness of chemoprevention (tamoxifen and raloxifene) in preventing breast cancer among women at high risk for the disease, uptake is low. The objective of this study was to determine the tradeoff preferences for various attributes associated with chemoprevention among women not currently taking the drugs.

METHODS

We used rating-based conjoint analysis to evaluate the relative importance of a number of attributes associated with chemoprevention, including risk of side effects, drug effectiveness, time needed to take the drugs, and availability of a blood test to see if the drugs were working in an Internet sample of women. We generated mean importance values and part-worth utilities for all attribute levels associated with taking chemoprevention. We then used multivariable linear regression to examine attribute importance scores controlling for participant age, race, Hispanic ethnicity, educational level, and a family history of breast cancer.

RESULTS

Overall interest in taking chemoprevention was low among the 1094 women included in the analytic sample, even for the scenario in which participants would receive the greatest benefit and fewest risks associated with taking the drugs. Time needed to take the pill for it to work and 5-year risk of breast cancer were the most important attributes driving tradeoff preferences between the chemoprevention scenarios.

CONCLUSIONS

Interest in taking chemoprevention among this sample of women at average risk was low. Addressing women's concerns about the time needed to take chemoprevention for it to work may help clinicians improve uptake of the drugs among those likely to benefit.

Incorporating Biomarkers in Studies of Chemoprevention

Despite Food and Drug Administration approval of tamoxifen and raloxifene for breast cancer risk reduction and endorsement by multiple agencies, uptake of these drugs for primary prevention in the United States is only 4% for risk eligible women likely to benefit from their use. Side effects coupled with incomplete efficacy and lack of a survival advantage are the likely reasons. This disappointing uptake, after the considerable effort and expense of large Phase III cancer incidence trials required for approval, suggests that a new paradigm is required. Current prevention research is focused on (1) refining risk prediction, (2) exploring behavioral and natural product interventions, and (3) utilizing novel translational trial designs for efficacy. Risk biomarkers will play a central role in refining risk estimates from traditional models and selecting cohorts for prevention trials. Modifiable risk markers called surrogate endpoint or response biomarkers will continue to be used in Phase I and II prevention trials to determine optimal dose or exposure and likely effectiveness from an intervention. The majority of Phase II trials will continue to assess benign breast tissue for response and mechanism of action biomarkers. Co-trials are those in which human and animal cohorts receive the same effective dose and the same tissue biomarkers are assessed for modulation due to the intervention, but then additional animals are allowed to progress to cancer development. These collaborations linking biomarker modulation and cancer prevention may obviate the need for cancer incidence trials for non-prescription interventions.

Impact of a primary care based intervention on breast cancer knowledge, risk perception and concern: A randomized, controlled trial

PURPOSE

To estimate the effects of a tablet-based, breast cancer risk education intervention for use in primary care settings (BreastCARE) on patients' breast cancer knowledge, risk perception and concern.

METHODS

From June 2011-August 2012, we enrolled women from two clinics, aged 40-74 years with no personal breast cancer history, and randomized them to the BreastCARE intervention group or to the control group. All patients completed a baseline telephone survey and risk assessment (via telephone for controls, via tablet computer in clinic waiting room prior to visit for intervention). All women were categorized as high or average risk based on the Referral Screening Tool, the Gail model or the Breast Cancer Surveillance Consortium model. Intervention patients and their physicians received an individualized risk report to discuss during the visit. All women completed a follow-up telephone survey 1-2 weeks after risk assessment. Post-test comparisons estimated differences at follow-up in breast cancer knowledge, risk perception and concern.

RESULTS

580 intervention and 655 control women completed follow-up interviews. Mean age was 56 years (SD = 9). At follow-up, 73% of controls and 71% of intervention women correctly perceived their breast cancer risk and 22% of controls and 24% of intervention women were very concerned about breast cancer. Intervention patients had greater knowledge (≥75% correct answers) of breast cancer risk factors at follow-up (24% vs. 16%; p = 0.002). In multivariable analysis, there were no differences in correct risk perception or concern, but intervention patients had greater knowledge ([OR] = 1.62; 95% [CI] = 1.19-2.23).

CONCLUSIONS

A simple, practical intervention involving physicians at the point of care can improve knowledge of breast cancer without increasing concern.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT01830933.

Barriers to preventive therapy for breast and other major cancers and strategies to improve uptake

The global cancer burden continues to rise and the war on cancer can only be won if improvements in treatment go hand in hand with therapeutic cancer prevention. Despite the availability of several efficacious agents, utilisation of preventive therapy has been poor due to various barriers, such as the lack of physician and patient awareness, fear of side effects, and licensing and indemnity issues. In this review, we discuss these barriers in detail and propose strategies to overcome them. These strategies include improving physician awareness and countering prejudices by highlighting the important differences between preventive therapy and cancer treatment. The importance of the agent-biomarker-cohort (ABC) paradigm to improve effectiveness of preventive therapy cannot be overemphasised. Future research to improve therapeutic cancer prevention needs to include improvements in the prediction of benefits and harms, and improvements in the safety profile of existing agents by experimentation with dose. We also highlight the role of drug repurposing for providing new agents as well as to address the current imbalance between therapeutic and preventive research. In order to move the field of therapeutic cancer prevention forwards, engagement with policymakers to correct research imbalance as well as to remove practical obstacles to implementation is also urgently needed.

Alternate dosing schedules for cancer chemopreventive agents

Pharmacologic interventions for cancer risk reduction involve the chronic administration of synthetic or natural agents to reduce or delay the occurrence of malignancy. Despite the strong evidence for a favorable risk-benefit ratio for a number of agents in several common malignancies such as breast and prostate cancer, the public's attitude toward cancer chemoprevention remains ambivalent, with the issue of toxicity associated with drugs being perceived as the main barrier to widespread use of preventive therapy by high-risk subjects. Among the strategies to overcome such obstacles to preventive therapies, two novel and potentially safer modes of administering agents are discussed in this paper. The first strategy is to lower the dose of drugs that are in common use in the adjuvant setting based on the notion that prevention of cancer cells from developing should require a lower dose than eradicating established tumor cells. A second approach is to adopt an intermittent administration similar to what is used in the chemotherapy setting in an attempt to minimize risks while retaining benefits. This article provides a detailed discussion of the principles and future development of these two approaches in the direction of a precision preventive medicine.

Use of the disulfiram/copper complex for breast cancer chemoprevention in MMTV-erbB2 transgenic mice

The disulfiram/copper complex (DS/Cu) has been demonstrated to exert potent anti-tumor effects in various types of cancer. At present, whether DS/Cu has chemopreventive effects on breast cancer development remains to be fully elucidated. In the present study, using MMTV-erbB2 transgenic mice, it was identified for the first time that DS/Cu treatment was able to inhibit cell growth in breast cancer cells while sparing normal cells in vitro, in addition to delaying the development of mammary tumor development in MMTV-erbB2 transgenic mice in vivo. Morphological examination demonstrated that DS/Cu treatment resulted in cell proliferation inhibition and apoptosis activation in vitro and in vivo. Furthermore, the present study observed that DS/Cu may inhibit proliferation via inhibition of AKT and cyclin D1 signaling and promote apoptosis via c-Jun N-terminal kinase activation and suppression of nuclear factor κB signaling. These results suggested that DS/Cu treatment may be a promising therapy for the prevention of erbB2-positive breast cancer.

Ki67 is a promising molecular target in the diagnosis of cancer (review)

The expression of Ki67 is strongly associated with tumor cell proliferation and growth, and is widely used in routine pathological investigation as a proliferation marker. The nuclear protein Ki67 (pKi67) is an established prognostic and predictive indicator for the assessment of biopsies from patients with cancer. Clinically, pKi67 has been shown to correlate with metastasis and the clinical stage of tumors. In addition, it has been shown that Ki67 expression is significantly higher malignant tissues with poorly differentiated tumor cells, as compared with normal tissue. According to its predictive role, pKi67 expression identifies subpopulations of patients who are more likely to respond to a given therapy. The Ki67 labeling index is an independent prognostic factor for survival rate, which includes all stages and grade categories. There is a correlation between the ratio of Ki67‑positive malignant cells and patient survival. It has been shown that blocking of Ki67 either by microinjection of antibodies or through the use of antisense oligonucleotides leads to the arrest of cell proliferation. Specifically, antisense oligonucleotides and antibodies against pKi67 have been shown to inhibit the progression of the cell cycle. The Ki67 protein is well characterized at the molecular level and is extensively used as a prognostic and predictive marker for cancer diagnosis and treatment. Increasing evidence indicates that Ki67 may be an effective target in cancer therapy. It therefore merits further development, including testing in more sophisticated in vitro and appropriate in vivo models. This review provides an overview of recent advances in this field.

A randomized, controlled trial to increase discussion of breast cancer in primary care

BACKGROUND

Assessment and discussion of individual risk for breast cancer within the primary care setting are crucial to discussion of risk reduction and timely referral.

METHODS

We conducted a randomized controlled trial of a multiethnic, multilingual sample of women ages 40 to 74 years from two primary care practices (one academic, one safety net) to test a breast cancer risk assessment and education intervention. Patients were randomly assigned to control or intervention group. All patients completed a baseline telephone survey and risk assessment (via telephone for controls, via tablet computer in clinic waiting room before visit for intervention). Intervention (BreastCARE) patients and their physicians received an individualized risk report to discuss during the visit. One-week follow-up telephone surveys with all patients assessed patient-physician discussion of family cancer history, personal breast cancer risk, high-risk clinics, and genetic counseling/testing.

RESULTS

A total of 655 control and 580 intervention women completed the risk assessment and follow-up interview; 25% were high-risk by family history, Gail, or Breast Cancer Surveillance Consortium risk models. BreastCARE increased discussions of family cancer history [OR, 1.54; 95% confidence interval (CI), 1.25-1.91], personal breast cancer risk (OR, 4.15; 95% CI, 3.02-5.70), high-risk clinics (OR, 3.84; 95% CI, 2.13-6.95), and genetic counseling/testing (OR, 2.22; 95% CI, 1.34-3.68). Among high-risk women, all intervention effects were stronger.

CONCLUSIONS

An intervention combining an easy-to-use, quick risk assessment tool with patient-centered risk reports at the point of care can successfully promote discussion of breast cancer risk reduction between patients and primary care physicians, particularly for high-risk women.

IMPACT

Next steps include scaling and dissemination of BreastCARE with integration into electronic medical record systems.

Lobular neoplasia

Lobular neoplasia (LN) is characterized by a dysfunctional E-cadherin-catenin axis, and loss of E-cadherin plays a causative role in the typical morphology of LN cells. LN is both a nonobligate precursor and a risk indicator of invasive breast cancer, and in particular, of invasive lobular carcinoma. Despite the evidence supporting the precursor role of LN, its impact on clinical management has been a matter of controversy, and conservative management remains the mainstay of treatment. In this article, an update is provided on the pathology and genetics of LN, and the management of these lesions in surgical practice is discussed.

Raloxifene and its role in breast cancer prevention

Raloxifene (Evista, Eli Lilly), a selective estrogen receptor modulator (SERM) and ligand for the estrogen receptor (ER), competes with endogenous estrogen for ER binding. Raloxifene is approved for the prevention and treatment of osteoporosis, and shows promise as a breast cancer prevention drug. Raloxifene may be a preferred agent over tamoxifen due to its side-effect profile; in particular, it does not stimulate the endometrium and is not associated with endometrial cancer. The mechanisms for the differential tissue effects of raloxifene compared with other SERMs are not completely understood; the roles of ERalpha and -beta, classic and alternative signaling pathways, and drug conformation are discussed in this review. The utility of raloxifene will depend on the outcome of trials that are now underway, as well as acceptance by high-risk women and their healthcare practitioners.

Use of Pharmacologic Interventions for Breast Cancer Risk Reduction: American Society of Clinical Oncology Clinical Practice Guideline

Purpose

To update the 2009 American Society of Clinical Oncology guideline on pharmacologic interventions for breast cancer (BC) risk reduction.

Methods

A systematic review of randomized controlled trials and meta-analyses published from June 2007 through June 2012 was completed using MEDLINE and Cochrane Collaboration Library. Primary outcome of interest was BC incidence (invasive and noninvasive). Secondary outcomes included BC mortality, adverse events, and net health benefits. Guideline recommendations were revised based on an Update Committee's review of the literature.

Results

Nineteen articles met the selection criteria. Six chemoprevention agents were identified: tamoxifen, raloxifene, arzoxifene, lasofoxifene, exemestane, and anastrozole.

Recommendations

In women at increased risk of BC age ≥ 35 years, tamoxifen (20 mg per day for 5 years) should be discussed as an option to reduce the risk of estrogen receptor (ER) –positive BC. In postmenopausal women, raloxifene (60 mg per day for 5 years) and exemestane (25 mg per day for 5 years) should also be discussed as options for BC risk reduction. Those at increased BC risk are defined as individuals with a 5-year projected absolute risk of BC ≥ 1.66% (based on the National Cancer Institute BC Risk Assessment Tool or an equivalent measure) or women diagnosed with lobular carcinoma in situ. Use of other selective ER modulators or other aromatase inhibitors to lower BC risk is not recommended outside of a clinical trial. Health care providers are encouraged to discuss the option of chemoprevention among women at increased BC risk. The discussion should include the specific risks and benefits associated with each chemopreventive agent.

Exemestane: one part of the chemopreventive spectrum for ER-positive breast cancer

Development of drugs to prevent breast cancer has focused largely on anti-estrogenic agents, leading to approval by the US FDA of two such agents for this purpose: tamoxifen and raloxifene. However, the uptake of these drugs by high-risk women and their primary care physicians has been limited, due in large part to a perceived unfavorable risk:benefit balance. The current focus is on aromatase inhibitors, which appear to have more acceptable side effects in addition to being more efficacious in reducing breast cancer risk in high-risk women. The placebo-controlled phase III MAP.3 trial tested the AI exemestane in high-risk women and documented a 65% relative reduction in total and a 73% reduction in ER-positive breast cancers in the intervention compared to the placebo group. Toxicities centered around musculoskeletal side effects, but in the relatively short 35-month median follow-up period, these did not impair quality-of-life. A bone study nested within MAP.3 demonstrated significant decreases in bone mineral density (BMD) and in structural parameters of bone quality. The strengths and weaknesses of preventive exemestane as evaluated in the MAP.3 trial are discussed as are relevant areas for future consideration: influence of obesity, alternative dosing, and biomarker use in phase III prevention trials of aromatase inhibitors.

Exemestane for breast cancer prevention: a critical shift?

The Mammary Prevention 3 (MAP.3) placebo-controlled randomized trial in 4,560 high-risk postmenopausal women showed a 65% reduction in invasive breast cancer with the use of exemestane at 35 months median follow-up. Few differences in adverse events were observed between the arms, suggesting a promising risk:benefit balance with exemestane for use in chemoprevention. Yet, the MAP.3 design and implementation raise concerns regarding limited data maturity and not prospectively including key bone-related and other toxicities as study end points. Exemestane for prevention is juxtaposed against selective estrogen receptor modulators and the other aromatase inhibitors. Additional issues for prevention, including the influence of obesity, alternative dosing, and biomarker use in phase III trials, are addressed.

SIGNIFICANCE

The recently completed MAP.3 trial of exemestane for breast cancer prevention offers a potential new standard for pharmaceutical risk reduction in high-risk postmenopausal women. In addition to describing key findings from the publication of MAP.3 and related trials, our review undertakes a detailed analysis of the strengths and weaknesses of MAP.3 as well as the implications for future prevention research.

[Third generation selective estrogen receptor modulators benefits beyond bone: effects on breast]

The selective estrogen receptor modulators (SERMs) are substances with estrogenic/anti-estrogen effect that act differently depending on the tissue and composition. Since the discovery that tamoxifen and raloxifene (RLX) had a breast cancer preventive effect, the search for the perfect SERM has been the goal. Thus, ospemifen, arzoxifene, lasofoxifene and bazedoxifene (BZA) appeared as third-generation SERMs. Among all them, only BZA reached the stage of clinical use. BZA has been shown to have an anti-estrogen effect in experimental studies, but not a protective effect on clinical breast cancer in pivotal clinical trials (301 and extensions). However, in these studies comparing BZA versus RLX and placebo, RLX has not shown the expected preventive effect on breast cancer. This lack of effect can be the consequence of the size and characteristics of BZA's studies in a population with low incidence of breast cancer.

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.

Breast cancer in young women: climbing for progress in care and knowledge

Approximately a third of newly diagnosed invasive breast cancers occur in women aged under 50 years and it is likely that the incidence of the disease in younger women will further increase as a result of demographic and lifestyle changes and progress in screening. Breast cancer in young women is different from that in older patients. Young women with breast cancer represent a distinct population for which tailored diagnostic, therapeutic and supportive interventions are required. This review highlights the complex diagnostic and therapeutic processes that women and care providers are faced with. Topics addressed include the need for more sensitive and specific diagnostic tools that are capable of detecting cancer in dense breasts, the development of individualized surgical and medical treatments in the early and advanced disease setting aimed at improving outcome and reducing long-term side effects, and adequate psychosocial interventions.

MGMT inhibition restores ERα functional sensitivity to antiestrogen therapy

Antiestrogen therapy resistance remains a huge stumbling block in the treatment of breast cancer. We have found significant elevation of O(6) methylguanine DNA methyl transferase (MGMT) expression in a small sample of consecutive patients who have failed tamoxifen treatment. Here, we show that tamoxifen resistance is accompanied by upregulation of MGMT. Further we show that administration of the MGMT inhibitor, O(6)-benzylguanine (BG), at nontoxic doses, leads to restoration of a favorable estrogen receptor alpha (ERα) phosphorylation phenotype (high p-ERα Ser167/low p-ERα Ser118), which has been reported to correlate with sensitivity to endocrine therapy and improved survival. We also show BG to be a dual inhibitor of MGMT and ERα. In tamoxifen-resistant breast cancer cells, BG alone or in combination with antiestrogen (tamoxifen [TAM]/ICI 182,780 [fulvestrant, Faslodex]) therapy enhances p53 upregulated modulator of apoptosis (PUMA) expression, cytochrome C release and poly (ADP-ribose) polymerase (PARP) cleavage, all indicative of apoptosis. In addition, BG increases the expression of p21(cip1/waf1). We also show that BG, alone or in combination therapy, curtails the growth of tamoxifen-resistant breast cancer in vitro and in vivo. In tamoxifen-resistant MCF7 breast cancer xenografts, BG alone or in combination treatment causes significant delay in tumor growth. Immunohistochemistry confirms that BG increases p21(cip1/waf1) and p-ERα Ser167 expression and inhibits MGMT, ERα, p-ERα Ser118 and ki-67 expression. Collectively, our results suggest that MGMT inhibition leads to growth inhibition of tamoxifen-resistant breast cancer in vitro and in vivo and resensitizes tamoxifen-resistant breast cancer cells to antiestrogen therapy. These findings suggest that MGMT inhibition may provide a novel therapeutic strategy for overcoming antiestrogen resistance.

Premenopausal serum androgens and breast cancer risk: a nested case-control study

INTRODUCTION

Prospective epidemiologic studies have consistently shown that levels of circulating androgens in postmenopausal women are positively associated with breast cancer risk. However, data in premenopausal women are limited.

METHODS

A case-control study nested within the New York University Women's Health Study was conducted. A total of 356 cases (276 invasive and 80 in situ) and 683 individually-matched controls were included. Matching variables included age and date, phase, and day of menstrual cycle at blood donation. Testosterone, androstenedione, dehydroandrosterone sulfate (DHEAS) and sex hormone-binding globulin (SHBG) were measured using direct immunoassays. Free testosterone was calculated.

RESULTS

Premenopausal serum testosterone and free testosterone concentrations were positively associated with breast cancer risk. In models adjusted for known risk factors of breast cancer, the odds ratios for increasing quintiles of testosterone were 1.0 (reference), 1.5 (95% confidence interval (CI), 0.9 to 2.3), 1.2 (95% CI, 0.7 to 1.9), 1.4 (95% CI, 0.9 to 2.3) and 1.8 (95% CI, 1.1 to 2.9; Ptrend = 0.04), and for free testosterone were 1.0 (reference), 1.2 (95% CI, 0.7 to 1.8), 1.5 (95% CI, 0.9 to 2.3), 1.5 (95% CI, 0.9 to 2.3), and 1.8 (95% CI, 1.1 to 2.8, Ptrend = 0.01). A marginally significant positive association was observed with androstenedione (P = 0.07), but no association with DHEAS or SHBG. Results were consistent in analyses stratified by tumor type (invasive, in situ), estrogen receptor status, age at blood donation, and menopausal status at diagnosis. Intra-class correlation coefficients for samples collected from 0.8 to 5.3 years apart (median 2 years) in 138 cases and 268 controls were greater than 0.7 for all biomarkers except for androstenedione (0.57 in controls).

CONCLUSIONS

Premenopausal concentrations of testosterone and free testosterone are associated with breast cancer risk. Testosterone and free testosterone measurements are also highly reliable (that is, a single measurement is reflective of a woman's average level over time). Results from other prospective studies are consistent with our results. The impact of including testosterone or free testosterone in breast cancer risk prediction models for women between the ages of 40 and 50 years should be assessed. Improving risk prediction models for this age group could help decision making regarding both screening and chemoprevention of breast cancer.

Major clinical research advances in gynecologic cancer in 2011

The annual review of 2011 comprised 11 themes of major research achievements in gynecologic oncology including breast cancer. A potential paradigm shift in the management of ovarian cancer was reviewed through comprehensive genomic analyses and a tumor-specific new intraoperative fluorescence imaging technique using folate receptor-α targeted agent, which is expected to improve intraoperative staging and more radical cytoreduction. In addition, updates of bevacizumab and poly (ADP-ribose) polymerase inhibitors, risk-reducing salpingo-oophorectomy, and risk evaluation of pelvic mass were discussed. Regarding cervical cancer, this review covered new findings on human papillomavirus vaccines and human papillomavirus tests as well as the current status of clinical trials on locally advanced cervical cancer. The promising role of sentinel lymph node biopsy in the management of early stage endometrial cancer was followed by two notable clinical researches on: exemestane, an aromatase inhibitor, for the prevention of breast cancer and eribulin, a non-taxane microtubule dynamics inhibitor for the treatment of metastatic breast cancer. Lastly, in premenopausal women with breast cancer, the effect of gonadotropin-releasing hormone analogue on the occurrence of chemotherapy-induced early menopause was discussed.

Exemestane for breast-cancer prevention in postmenopausal women

BACKGROUND

Tamoxifen and raloxifene have limited patient acceptance for primary prevention of breast cancer. Aromatase inhibitors prevent more contralateral breast cancers and cause fewer side effects than tamoxifen in patients with early-stage breast cancer.

METHODS

In a randomized, placebo-controlled, double-blind trial of exemestane designed to detect a 65% relative reduction in invasive breast cancer, eligible postmenopausal women 35 years of age or older had at least one of the following risk factors: 60 years of age or older; Gail 5-year risk score greater than 1.66% (chances in 100 of invasive breast cancer developing within 5 years); prior atypical ductal or lobular hyperplasia or lobular carcinoma in situ; or ductal carcinoma in situ with mastectomy. Toxic effects and health-related and menopause-specific qualities of life were measured.

RESULTS

A total of 4560 women for whom the median age was 62.5 years and the median Gail risk score was 2.3% were randomly assigned to either exemestane or placebo. At a median follow-up of 35 months, 11 invasive breast cancers were detected in those given exemestane and in 32 of those given placebo, with a 65% relative reduction in the annual incidence of invasive breast cancer (0.19% vs. 0.55%; hazard ratio, 0.35; 95% confidence interval [CI], 0.18 to 0.70; P=0.002). The annual incidence of invasive plus noninvasive (ductal carcinoma in situ) breast cancers was 0.35% on exemestane and 0.77% on placebo (hazard ratio, 0.47; 95% CI, 0.27 to 0.79; P=0.004). Adverse events occurred in 88% of the exemestane group and 85% of the placebo group (P=0.003), with no significant differences between the two groups in terms of skeletal fractures, cardiovascular events, other cancers, or treatment-related deaths. Minimal quality-of-life differences were observed.

CONCLUSIONS

Exemestane significantly reduced invasive breast cancers in postmenopausal women who were at moderately increased risk for breast cancer. During a median follow-up period of 3 years, exemestane was associated with no serious toxic effects and only minimal changes in health-related quality of life. (Funded by Pfizer and others; NCIC CTG MAP.3 ClinicalTrials.gov number, NCT00083174.).

Recommendations for a lifestyle which could prevent breast cancer and its relapse: physical activity and dietetic aspects

External factors such as eating habits and physical activity have an important impact on breast cancer risk. This paper reviews the literature on the relationship between breast cancer and lifestyle. It aims to produce recommendations regarding physical activity and dietary intake for clinical practice. Although strong clinical evidence of the impact of lifestyle modifications is still lacking, practising healthy eating should be encouraged for the prevention of cancer, its occurrence or relapse. Physical activity is recommended to avoid excessive weight gain. For example, the beneficial effects on the risk of breast cancer could be achieved by walking half an hour per day. Three to five hours per week of moderate physical exercise therefore should be recommended for optimising the reduction of the risk of cancer. For most women, moderate to intense activity, such as heavy housework, brisk walking, or dancing, could provide an effective level of activity to keep reduce the risk of breast cancer.

Treatment of osteoporosis and reduction in risk of invasive breast cancer in postmenopausal women with raloxifene

INTRODUCTION

Raloxifene, a non-steroidal selective estrogen receptor modulator (SERM), offers a new dimension for the treatment and prevention of osteoporosis and risk reduction of invasive breast cancer in postmenopausal populations at high risk. Both osteoporosis and breast cancer are important public health issues for postmenopausal women. It is well known that estrogen and estrogen receptors play an important role in the pathogenesis of both diseases. Initially, hormone replacement therapy (HRT) was used for the purpose of preventing and treating postmenopausal osteoporosis. However, HRT significantly contributed to an increase in breast cancer risk. The SERM, raloxifene, is used for the prevention and for the treatment of postmenopausal osteoporosis and reducing the risk of invasive breast cancer in postmenopausal women.

AREAS COVERED

This article reviews the emerging evidence of the efficacy of raloxifene in postmenopausal women, summarizes the results and places in perspective their therapeutic uses for women having either a high risk of osteoporosis or breast cancer. Emerging clinical evidence suggests bisphosphonates, currently used as drugs for the treatment of osteoporosis, may also reduce breast cancer risk. The status of other SERMs and bisphosphonates are included for completeness. A Medline search of raloxifene, osteoporosis, breast cancer and SERMs was used to derive a database of 355 references.

EXPERT OPINION

Readers will understand the value of raloxifene to prevent osteoporosis and breast cancer in postmenopausal women. Although most women do not require pharmacotherapy for menopausal symptoms, many are severely affected by osteoporosis or breast cancer at and beyond menopause and, for such women, pharmacologic intervention is important if they are to retain an acceptable quality of life. It is reasonable to use raloxifene or bisphosphonate as an appropriate drug that targets symptom-free postmenopausal women for treatment and prevention of osteoporosis but raloxifene is proven to reduce the incidence of invasive breast cancer.

Breast cancer chemoprevention: progress and controversy

The chemoprevention of breast cancer using pharmacologic agents has had substantial clinical success. Randomized clinical trials evaluating selective estrogen-receptor modulators (SERMs) have shown that these agents reduce the incidence of breast cancer by up to 50% in healthy women at increased risk for the development of the disease. SERMs have been of particular value in women with biopsy-proven risk factors, including atypical hyperplasia or lobular carcinoma in situ of the breast. The agents of established value are important options for women today, and efforts are under way to identify additional more effective therapies.

Biological reprogramming in acquired resistance to endocrine therapy of breast cancer

Endocrine therapies targeting the proliferative effect of 17β-estradiol through estrogen receptor α (ERα) are the most effective systemic treatment of ERα-positive breast cancer. However, most breast tumors initially responsive to these therapies develop resistance through molecular mechanisms that are not yet fully understood. The long-term estrogen-deprived (LTED) MCF7 cell model has been proposed to recapitulate acquired resistance to aromatase inhibitors in postmenopausal women. To elucidate this resistance, genomic, transcriptomic and molecular data were integrated into the time course of MCF7-LTED adaptation. Dynamic and widespread genomic changes were observed, including amplification of the ESR1 locus consequently linked to an increase in ERα. Dynamic transcriptomic profiles were also observed that correlated significantly with genomic changes and were predicted to be influenced by transcription factors known to be involved in acquired resistance or cell proliferation (for example, interferon regulatory transcription factor 1 and E2F1, respectively) but, notably, not by canonical ERα transcriptional function. Consistently, at the molecular level, activation of growth factor signaling pathways by EGFR/ERBB/AKT and a switch from phospho-Ser118 (pS118)- to pS167-ERα were observed during MCF7-LTED adaptation. Evaluation of relevant clinical settings identified significant associations between MCF7-LTED and breast tumor transcriptome profiles that characterize ERα-negative status, early response to letrozole and tamoxifen, and recurrence after tamoxifen treatment. In accordance with these profiles, MCF7-LTED cells showed increased sensitivity to inhibition of FGFR-mediated signaling with PD173074. This study provides mechanistic insight into acquired resistance to endocrine therapies of breast cancer and highlights a potential therapeutic strategy.

The National Cancer Institute of Canada Clinical Trials Group MAP.3 trial: an international breast cancer prevention trial

Several large phase iii trials have demonstrated that tamoxifen—and more recently, raloxifene—can effectively reduce the incidence of invasive breast cancer by 50%. However, these selective estrogen receptor modulators can also be associated with several rare, but serious, adverse events. Recently, the third-generation aromatase inhibitors (ais) have demonstrated excellent efficacy in adjuvant breast cancer trials, and they show particular promise in the breast cancer prevention setting. The National Cancer Institute of Canada Clinical Trials Group (ncic ctg) has developed a randomized phase iii study to determine the efficacy of an ai (exemestane) to reduce the incidence of invasive breast cancer in postmenopausal women at an increased risk for developing breast cancer. The ncic ctg map.3 (ExCel) trial is a double-blind placebo-controlled multicentre, multinational trial. Based on the known preclinical and clinical profile of the ais, a greater reduction in breast cancer incidence with fewer side effects is hypothesized with this class of agents than with tamoxifen or raloxifene.

Establishing a family risk assessment clinic for breast cancer

Breast cancer is the most common cancer affecting European women and the leading cause of cancer-related death. A total of 15-20% of women who develop breast cancer have a family history and 5-10% a true genetic predisposition. The identification and screening of women at increased risk may allow early detection of breast cancer and improve prognosis. We established a family risk assessment clinic in May 2005 to assess and counsel women with a family history of breast cancer, to initiate surveillance, and to offer risk-reducing strategies for selected high-risk patients. Patients at medium or high risk of developing breast cancer according to NICE guidelines were accepted. Family history was determined by structured questionnaire and interview. Lifetime risk of developing breast cancer was calculated using Claus and Tyrer-Cuzick scoring. Risk of carrying a breast cancer-related gene mutation was calculated using the Manchester system. One thousand two hundred and forty-three patients have been referred. Ninety-two percent were at medium or high risk of developing breast cancer. Formal assessment of risk has been performed in 368 patients, 73% have a high lifetime risk of developing breast cancer, and 72% a Manchester score >or=16. BRCA1/2 mutations have been identified in 14 patients and breast cancer diagnosed in two. Our initial experience of family risk assessment has shown there to be a significant demand for this service. Identification of patients at increased risk of developing breast cancer allows us to provide individuals with accurate risk profiles, and enables patients to make informed choices regarding their follow-up and management.

Prevention Strategies with Aromatase Inhibitors

Aromatase (estrogen synthetase) inhibitors are superior to tamoxifen in terms of both efficacy and toxicity in the treatment of advanced breast cancer and also in the neoadjuvant setting. Recent results from the Arimidex, Tamoxifen, Alone or in Combination adjuvant trial showed a marked reduction in contralateral primary breast cancer with anastrozole, an apparent prevention effect. A similar effect was seen in the MA.17 adjuvant trial comparing letrozole with placebo after 5 years of adjuvant tamoxifen. This has accelerated interest in aromatase inhibitors as primary preventive therapy. Two studies being conducted by the National Cancer Institute of Canada's Clinical Trials Group select women by virtue of mammographic breast density. The International Breast Cancer Intervention Study 2 trial randomizes women at elevated risk to anastrozole or placebo. Because of its steroidal structure, exemestane may be more effective than the nonsteroidal aromatase inhibitors and may protect bone and lipid metabolism from the effects of estrogen ablation. Elevated prostaglandin E2 levels from cyclooxygenase-2 induction by preinvasive and invasive breast lesions increase a number of tumor-promoting pathways, including aromatase, as well as angiogenetic, antiapoptotic, and others. Additive or synergistic effects between celecoxib, a cyclooxygenase-2 inhibitor, and exemestane have been demonstrated and have led to the National Cancer Institute of Canada's Clinical Trials Group MAP.3 trial, which will randomize women at elevated risk to placebo or to exemestane with or without celecoxib. The efficacy and long-term toxicity data from the aromatase inhibitor prevention trials, and the identification of risk profiles from trial results, are awaited with interest.

Breast cancer chemoprevention - a vision not yet realized

Despite recent advances in the surgical and medical treatment of breast cancer, the number of patients dying from the disease is still high. In addition to improvements of early diagnosis and treatment, the overall mortality of breast cancer could be reduced by means of preventive intervention in both women with particularly normal and with high risk. Preventing the potentially deadly disease is presumably more effective than treatment, for life quality issues as well as for the economic perspective. Chemoprevention though is still a research field with results from large prevention trials being discussed controversially. For women with a defined increased risk for breast cancer, tamoxifen may be a choice for chemoprevention, balancing carefully benefits against risks. With promising results in adjuvant settings, aromatase inhibitors may deliver better prevention treatment options in the future, nevertheless, more research is needed to reliably predict risk on an individual basis in the future.