Validating and improving models for projecting the absolute risk of breast cancer

Competing risks and multivariate outcomes in epidemiological and clinical trial research

Data analysis methods for the study of treatments or exposures in relation to a clinical outcome in the presence of competing risks have a long history, often with inference targets that are hypothetical, thereby requiring strong assumptions for identifiability with available data. Here data analysis methods are considered that are based on single and higher dimensional marginal hazard rates, quantities that are identifiable under standard independent censoring assumptions. These lead naturally to joint survival function estimators for outcomes of interest, including competing risk outcomes, and provide the basis for addressing a variety of data analysis questions. These methods will be illustrated using simulations and Women's Health Initiative cohort and clinical trial data sets, and additional research needs will be described.

Prediction of breast cancer risk among women of the Mariana Islands: the BRISK retrospective case-control study

OBJECTIVES

To develop a breast cancer risk prediction model for Chamorro and Filipino women of the Mariana Islands and compare its performance to that of the Breast Cancer Risk Assessment Tool (BCRAT).

DESIGN

Case-control study.

SETTING

Clinics/facilities and other community-based settings on Guam and Saipan (Northern Mariana Islands).

PARTICIPANTS

245 women (87 breast cancer cases and 158 controls) of Chamorro or Filipino ethnicity, age 25-80 years, with no prior history of cancer (other than skin cancer), residing on Guam or Saipan for at least 5 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

Breast cancer risk models were constructed using combinations of exposures previously identified to affect breast cancer risk in this population, population breast cancer incidence rates and all-cause mortality rates for Guam.

RESULTS

Models using ethnic-specific relative risks performed better than those with relative risks estimated from all women. The model with the best performance among both ethnicities (the Breast Cancer Risk Model (BRISK) model; area under the receiver operating characteristic curve (AUC): 0.64 and 0.67 among Chamorros and Filipinos, respectively) included age at menarche, age at first live birth, number of relatives with breast cancer and waist circumference. The 10-year breast cancer risk predicted by the BRISK model was 1.28% for Chamorros and 0.89% for Filipinos. Performance of the BCRAT was modest among both Chamorros (AUC: 0.60) and Filipinos (AUC: 0.55), possibly due to incomplete information on BCRAT risk factors.

CONCLUSIONS

The ability to develop breast cancer risk models for Mariana Islands women is constrained by the small population size and limited availability of health services and data. Nonetheless, we have demonstrated that breast cancer risk prediction models with adequate discriminatory performance can be built for small populations such as in the Mariana Islands. Anthropometry, in particular waist circumference, was important for estimating breast cancer risk in this population.

Mortality Associated with Healthy Eating Index Components and an Empirical-Scores Healthy Eating Index in a Cohort of Postmenopausal Women

BACKGROUND

Studies of diet and chronic disease include a recent important focus on dietary patterns. Patterns are typically defined by listing dietary variables and by totaling scores that reflect whether consumption is encouraged or discouraged for listed variables. However, precision may be improved by including total energy consumption among the dietary variables and by scoring dietary variables empirically.

OBJECTIVES

To relate Healthy Eating Index (HEI)-2010 components and total energy intake to all-cause and cause-specific mortality in Women's Health Initiative (WHI) cohorts and to define and evaluate an associated Empirical-Scores Healthy Eating Index (E-HEI).

METHODS

Analyses are conducted in WHI cohorts (n = 67,247) of healthy postmenopausal women, aged 50-79 y, when enrolled during 1993-1998 at 40 US clinical centers, with embedded nutrition biomarker studies. Replicate food-frequency assessments for HEI-2010 ratio variables and doubly labeled water total energy assessments, separated by ∼6 mo, are used as response variables to jointly calibrate baseline dietary data to reduce measurement error influences, using 2 nutrition biomarker studies (n = 199). Calibrated dietary variables are associated with mortality risk, and an E-HEI is defined, using cross-validated HR regression estimation.

RESULTS

Of 15 dietary variables considered, all but empty calories calibrated well. Ten variables related significantly (P < 0.05) to total mortality, with favorable fruit, vegetable, whole grain, refined grain, and unsaturated fat associations and unfavorable sodium, saturated fat, and total energy associations. The E-HEI had cross-validated total mortality HRs (95% CIs) of 0.87 (0.82, 0.93), 0.80 (0.76, 0.86), 0.77 (0.72, 0.82), and 0.74 (0.69, 0.79) respectively, for quintiles 2 through 5 compared with quintile 1. These depart more strongly from the null than do HRs for HEI-2010 quintiles, primarily because of total energy.

CONCLUSIONS

Mortality among US postmenopausal women depends strongly on diet, as evidenced by a new E-HEI that differs substantially from earlier dietary pattern score specifications.

Accuracy of Perceived Breast Cancer Risk in Black and White Women with an Elevated Risk

Introduction

Perceived breast cancer risk predicts screening behaviors. However, perceived risk is often inaccurate, notably in Black women, who often underestimate their risk despite having higher disease-specific mortality rates. We examined predictors of perceived breast cancer risk, and its impact on surveillance.

Methods

We used baseline data from a randomized trial targeting unaffected women recruited by relatives with early-onset breast cancer. Data collection occurred between 2012 and 2013. Accuracy of perceived risk was assessed by comparing perceived risk to objective lifetime breast cancer risks, calculated with the Gail and Claus models. A multivariate mixed model regression examined predictors of accuracy of perceived risk. The impact of perceived risk on breast cancer surveillance was assessed with one-way ANOVAS comparing Black to White women.

Results

Among participants, 21.4% self-identified as Black and 78.6% as White. Overall, 72.9% (n=247/339), 16.2% (n=55/339), and 10.9% (n=37/339) of participants overestimated, accurately perceived, and underestimated, respectively, their lifetime breast cancer risk. Race did not predict the accuracy of risk perception. Younger participants were more likely to overestimate their risk (β=-.455; CI [-.772, -.138]; P=.005). MRI utilization was predicted by a higher objective risk (F 1,263 [= 30.271]; P<.001) and more accurate risk perception (P=.010; Fisher's exact test).

Conclusions

Most women with a family history of early-onset breast cancer inaccurately perceived their risk for developing the disease. Younger women were more likely to overestimate their risk. Findings can guide the development of tailored interventions to improve adherence to breast cancer surveillance recommendations.

Gail Model Improves the Diagnostic Performance of the Fifth Edition of Ultrasound BI-RADS for Predicting Breast Cancer: A Multicenter Prospective Study

RATIONALE AND OBJECTIVES

The sonographic appearance of benign and malignant breast nodules overlaps to some extent, and we aimed to assess the performance of the Gail model as an adjunctive tool to ultrasound (US) Breast Imaging Reporting and Data System (BI-RADS) for predicting the malignancy of nodules.

MATERIALS AND METHODS

From 2018 to 2019, 2607 patients were prospectively enrolled by 35 health care facilities. An individual breast cancer risk was assessed by the Gail model. Based on B-mode US, color Doppler, and elastography, all nodules were evaluated according to the fifth edition of BI-RADS, and these nodules were all confirmed later by pathology.

RESULTS

We demonstrated that the Gail model, age, tumor size, tumor shape, growth orientation, margin, contour, acoustic shadowing, microcalcification, presence of duct ectasia, presence of architectural distortion, color Doppler flow, BI-RADS, and elastography score were significantly related to breast cancer (all p < 0.001). The sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under the curve (AUC) for combining the Gail model with the BI-RADS category were 95.6%, 91.3%, 85.0%, 97.6%, 92.8%, and 0.98, respectively. Combining the Gail model with the BI-RADS showed better diagnostic efficiency than the BI-RADS and Gail model alone (AUC 0.98 vs 0.80, p < 0.001; AUC 0.98 vs 0.55, p < 0.001) and demonstrated a higher specificity than the BI-RADS (91.3% vs 59.4%, p < 0.001).

CONCLUSION

The Gail model could be used to differentiate malignant and benign breast lesions. Combined with the BI-RADS category, the Gail model was adjunctive to US for predicting breast lesions for malignancy. For the diagnosis of malignancy, more attention should be paid to high-risk patients with breast lesions.

The Role of Exosomes in Breast Cancer Diagnosis

The importance of molecular re-characterization of metastatic disease with the purpose of monitoring tumor evolution has been acknowledged in numerous clinical guidelines for the management of advanced malignancies. In this context, an attractive alternative to overcome the limitations of repeated tissue sampling is represented by the analysis of peripheral blood samples as a 'liquid biopsy'. In recent years, liquid biopsies have been studied for the early diagnosis of cancer, the monitoring of tumor burden, tumor heterogeneity and the emergence of molecular resistance, along with the detection of minimal residual disease. Interestingly, liquid biopsy consents the analysis of circulating tumor cells, circulating tumor DNA and extracellular vesicles (EVs). In particular, EVs play a crucial role in cell communication, carrying transmembrane and nonmembrane proteins, as well as metabolites, lipids and nucleic acids. Of all EVs, exosomes mirror the biological fingerprints of the parental cells from which they originate, and therefore, are considered one of the most promising predictors of early cancer diagnosis and treatment response. The present review discusses current knowledge on the possible applications of exosomes in breast cancer (BC) diagnosis, with a focus on patients at higher risk.

Evaluating the predictive performance of malaria antibodies and FCGR3B gene polymorphisms on Plasmodium falciparum infection outcome: a prospective cohort study

Background

Malaria antigen-specific antibodies and polymorphisms in host receptors involved in antibody functionality have been associated with different outcomes of Plasmodium falciparum infections. Thus, to identify key prospective malaria antigens for vaccine development, there is the need to evaluate the associations between malaria antibodies and antibody dependent host factors with more rigorous statistical methods. In this study, different statistical models were used to evaluate the predictive performance of malaria-specific antibodies and host gene polymorphisms on P. falciparum infection in a longitudinal cohort study involving Ghanaian children.

Methods

Models with different functional forms were built using known predictors (age, sickle cell status, blood group status, parasite density, and mosquito bed net use) and malaria antigen-specific immunoglobulin (Ig) G and IgG subclasses and FCGR3B polymorphisms shown to mediate antibody-dependent cellular functions. Malaria antigens studied were Merozoite surface proteins (MSP-1 and MSP-3), Glutamate Rich Protein (GLURP)-R0, R2, and the Apical Membrane Antigen (AMA-1). The models were evaluated through visualization and assessment of differences between the Area Under the Receiver Operating Characteristic Curve and Brier Score estimated by suitable internal cross-validation designs.

Results

This study found that the FCGR3B-c.233C>A genotype and IgG against AMA1 were relatively better compared to the other antibodies and FCGR3B genotypes studied in classifying or predicting malaria risk among children.

Conclusions

The data supports the P. falciparum, AMA1 as an important malaria vaccine antigen, while FCGR3B-c.233C>A under the additive and dominant models of inheritance could be an important modifier of the effect of malaria protective antibodies.

Breast cancer risk assessment and management programs: A practical guide

Breast cancer risk assessment continues to evolve as emerging knowledge of breast cancer risk drivers and modifiers enables better identification of high-risk women who may benefit from increased screening or targeted risk-reduction protocols. The ongoing development of breast cancer Risk Assessment and Management Programs (RAMPs) presents an opportunity to decrease breast cancer disease incidence with evidence-based interventions. The goal of this review was to provide a practical guide for providers seeking to establish or update a breast cancer risk assessment and management program. We outline genetic/familial, personal, reproductive, and lifestyle-related factors while discussing the incorporation of risk modeling for precise risk estimate personalization. We further describe the process for determining a risk management plan: information gathering, generation of a risk profile, and articulation and implementation of risk reduction. We also include an overview of clinical workflows in breast cancer management programs and underlines the logistics of establishing a program as well as general principles for guiding the formulation of an individualized risk management plan. We discuss practical considerations, such as clinic structure and operation, allocation of resources, and patient education. Other critical aspects of program design, including identification of the target population, delineation of the core components of the clinical experience, definition of provider roles, description of referral mechanisms, and the launching of a marketing plan are also addressed. The process of risk assessment is both anxiety-provoking and empowering for women at increased risk. New knowledge has enabled strategies to both understand the risk and control it through evidence-based risk management. These benefits can now be realized by an increasing number of unaffected, high-risk patients collaborating with risk management practitioners. Continuation of these efforts will lead to further progress in both risk stratification and risk management of women at elevated breast cancer risk in the near future.

A way forward for cancer prevention therapy: personalized risk assessment

Cancer is characterized by genetic and molecular aberrations whose number and complexity increase dramatically as cells progress along the spectrum of carcinogenesis. The pharmacologic application of agents in the context of a lower burden of dysregulated cellular processes constitutes an efficient strategy to enhance therapeutic efficacy, and underlies the rationale for using cancer prevention agents in high-risk populations. A longstanding barrier to implementing this strategy is that the risk in the general population is low for any given cancer, many people would have to be treated in order to benefit a few. Therefore, identifying and treating high-risk individuals will improve the risk: benefit ratio. Currently, risk is defined by considering a relatively low number of factors. A strategy that considers multiple factors has the ability to define a much-higher-risk cohort than the general population. This article will review the rationale for evaluating multiple risk factors so as to identify individuals at highest risk. It will use breast and lung cancer as examples, will describe currently available risk assessment tools, and will discuss ongoing efforts to expand the impact of this approach. The high potential of this strategy to provide a way forward for developing cancer prevention therapy will be highlighted.

Ultrasound for Breast Cancer Screening in High-Risk Women: Results From a Population-Based Cancer Screening Program in China

Background: Ultrasound is an important modality for breast cancer screening. However, the evidence on the effectiveness of ultrasound screening in population-based cancer screening program in lacking. We aimed to evaluate the diagnostic yield of ultrasound screening in a population-based breast cancer screening in China.

Methods: The analyses were conducted in the context of the Cancer Screening Program in Urban China, which recruited 1,938,996 eligible participants aged 40–69 years from 16 provinces in China from 2012 to 2016. We included 72,250 women assessed to be high-risk for breast cancer who undertook ultrasound screening per study protocol. Diagnostic yield according to the Breast Imaging Reporting and Data System (BI-RADS) was evaluated. Risk factors associated with the positive findings of ultrasound were also explored by univariate and multivariable logistic regression analyses.

Results: Overall, there were 9,765 (13.51%) women had positive findings of ultrasound screening, including 8,487 (11.75%), 1,210 (1.67%), and 68 (0.09%) of BI-RADS categories of III, IV, and V, respectively. Younger ages, late age of 1st live birth and short-term breast feeding were found to be positively associated with positive findings under ultrasound in multivariate analyses stratified by menopause status and family history of breast cancer. Multivariable prediction models were constructed and yielded only modest prediction accuracy, with AUCs around 0.55.

Conclusions: We found the diagnostic yield of ultrasound screening for breast cancer in high-risk population was satisfactory. Prediction models based on environmental risk factors had limited prediction accuracy and need to be improved in the future.

Benign Breast Diseases: Evaluation and Management

Benign breast disease is a spectrum of common disorders. The majority of patients with a clinical breast lesion will have benign process. Management involves symptom control when present, pathologic-based and imaging-based evaluation to distinguish from a malignant process, and counseling for patients that have an increased breast cancer risk due to the benign disorder.

Risk Reduction Strategies in Breast Cancer Prevention

Evaluating the risk of breast cancer makes it possible to identify women with a high risk of developing breast cancer in the future. Adopting a healthier lifestyle, involving diet and exercise, is one way of reducing this risk-but there are other, non-modifiable risk factors, such as family history, genetics and diagnosis of premalignant lesions. In this high-risk population, the tracking must be rigorous and involve the participation of the patient herself, earlier and more frequent clinical assessment, and the use of imaging screening. Agents such as tamoxifen, raloxifene and aromatase inhibitors may be used in chemoprevention and may reduce the risk substantially. The risks and benefits must be assessed, and one must discuss with the patient her adverse events and the decision regarding the best treatment. Women who carry the BRCA1/2 mutation (very high risk) can benefit from prophylactic surgical interventions, such as bilateral mastectomy and/or bilateral salpingo-oophorectomy. This group of patients must be monitored by a multidisciplinary team, providing explanations prior to surgery regarding the surgical treatment offered, the reconstruction techniques, and the risks and complications.

Preventive and Risk Reduction Strategies for Women at High Risk of Developing Breast Cancer: a Review

Breast cancer is the most commonly diagnosed invasive cancer among women. Many factors, both genetic and non-genetic, determine a woman's risk of developing breast cancer and several breast cancer risk prediction models have been proposed. It is vitally important to risk stratify patients as there are now effective preventive strategies available. All women need to be counseled regarding healthy lifestyle recommendations to decrease breast cancer risk. As such, management of these women requires healthcare professionals to be familiar with additional risk factors so that timely recommendations can be made on surveillance/risk-reducing strategies. Breast cancer risk reduction strategies can be better understood by encouraging the women at risk to participate in clinical trials to test new strategies for decreasing the risk. This article reviews the advances in the identification of women at high risk of developing breast cancer and also reviews the strategies available for breast cancer prevention.

Stepped-Care, Community Clinic Interventions to Promote Mammography Use among Low-Income Rural African American Women

Few studies have investigated community clinic-based interventions to promote mammography screening among rural African American women. This study randomized older low-income rural African American women who had not participated in screening in the previous 2 years to a theory-based, personalized letter or usual care; no group differences in mammography rate were evident at 6-month follow-up. Women who had not obtained a mammogram were then randomized to a tailored call delivered by community health care workers or a tailored letter. There were no group differences in mammography rates after the second 6-month follow-up. However, among women who had never had a mammogram, the tailored call was more effective in promoting mammography use. Tailored counseling may be an effective screening promotion strategy for hard-to-reach rural African American women with no history of screening. Further research into this strategy may facilitate efforts to reduce health disparities in underserved low-income rural African American populations.

Effects of a risk-based online mammography intervention on accuracy of perceived risk and mammography intentions

OBJECTIVE

This experiment tested the effects of an individualized risk-based online mammography decision intervention. The intervention employs exemplification theory and the Elaboration Likelihood Model of persuasion to improve the match between breast cancer risk and mammography intentions.

METHODS

2918 women ages 35-49 were stratified into two levels of 10-year breast cancer risk (<1.5%; ≥1.5%) then randomly assigned to one of eight conditions: two comparison conditions and six risk-based intervention conditions that varied according to a 2 (amount of content: brief vs. extended) x 3 (format: expository vs. untailored exemplar [example case] vs. tailored exemplar) design. Outcomes included mammography intentions and accuracy of perceived breast cancer risk.

RESULTS

Risk-based intervention conditions improved the match between objective risk estimates and perceived risk, especially for high-numeracy women with a 10-year breast cancer risk ≤1.5%. For women with a risk≤1.5%, exemplars improved accuracy of perceived risk and all risk-based interventions increased intentions to wait until age 50 to screen.

CONCLUSION

A risk-based mammography intervention improved accuracy of perceived risk and the match between objective risk estimates and mammography intentions.

PRACTICE IMPLICATIONS

Interventions could be applied in online or clinical settings to help women understand risk and make mammography decisions.

Raloxifene: A Selective Estrogen Receptor Modulator for Reducing the Risk of Invasive Breast Cancer in Postmenopausal Women

Raloxifene hydrochloride is a selective estrogen receptor modulator that has antiestrogenic effects on breast and endometrial tissue and estrogenic effects on bone, lipid metabolism and blood clotting. Tamoxifen is the prototypical selective estrogen receptor modulator and reduces the risk of both in situ and invasive breast cancers by half when compared with placebo. The limitations on the use of tamoxifen for breast cancer risk reduction relate to its well-known, but rare, side effects. A number of clinical trials have established the benefit of raloxifene on osteoporosis and fracture. Raloxifene significantly improves serum lipids and serum markers of cardiovascular disease risk, but has no significant effect on the risk of primary coronary events. In several osteoporosis trials and the Raloxifene Use for The Heart (RUTH) trial, raloxifene decreased the risk of estrogen receptor-positive breast cancer by 44–90%. In the Study of Tamoxifen And Raloxifene (STAR) trial, the effect of raloxifene on invasive breast cancer was equivalent to that of tamoxifen, with more favorable effects on uterine malignancy and clotting events. Symptomatic side effects are acceptable. In total, the available data indicate that raloxifene represents an acceptable alternative to tamoxifen for the reduction of the risk of postmenopausal breast cancer in high-risk women. The potential market for a compound shown to reduce the risk of breast cancer in postmenopausal women who are at increased risk for breast cancer is more than 10 million women in the USA alone.

Gaining control over breast cancer risk: Transforming vulnerability, uncertainty, and the future through clinical trial participation - a qualitative study

Concepts of disease risk and its management are central to processes of medicalisation and pharmaceuticalisation. Through a narrative perspective, this paper aims to understand how such macro-level developments may (or may not) be experienced individually, and how an algorithm that is used for recruitment into a clinical trial may structure individual notions of being 'at risk' and 'in need of treatment'. We interviewed 31 women participating in the Study of Tamoxifen and Raloxifene (STAR), a chemoprevention trial conducted in the US between 1999 and 2006. Interviews were thematically analysed. Women in the study had experienced the threat of breast cancer and felt vulnerable to developing the disease prior to STAR participation. The diagnosis of 'being at risk' for cancer through an algorithm that determined risk-eligibility for STAR, opened up the possibility for the women to heal. The trial became a means to recognise and collectivise the women's experiences of vulnerability. Through medication intake, being cared for by study coordinators, and the sense of community with other STAR participants, trial participation worked to transform women's lives. Such transformative experiences may nevertheless have been temporary, enduring only as long as the close links to the medical institution through trial participation lasted.

Chemoprevention or mastectomy for women at high risk of developing breast cancer

Breast cancer (BC) is the most commonly diagnosed invasive cancer among women; in developed countries, BC occurs in one out of eight women during her lifetime. Many factors, both genetic and non-genetic, determine a woman's risk of breast cancer and several mathematical models have been proposed that determine the risk. It is important to identify those at high risk, as there are now effective preventive strategies, such as chemoprevention therapy and risk-reduction surgery. Risk-reduction agents are recommended for women aged 35 years or more who are at high risk of breast cancer. Tamoxifen is presently deemed to be the agent of choice. However, raloxifene may be preferable, at least for some postmenopausal women, because of its lack of effect on the endometrium and the reduced incidence of venous thromboembolic events compared with tamoxifen. Prophylactic surgery has been widely investigated. Bilateral mastectomy decreases the risk of developing breast cancer by approximately 90% in women at moderate or high risk and in known BRCA1/2 mutation carriers. This review summarizes the recent advances in the identification of women at high risk of developing breast cancer and reports on the strategies used to prevent breast cancer; the risk-benefit balance of such preventive choices is also briefly analyzed.

Risk Classification with an Adaptive Naive Bayes Kernel Machine Model

Genetic studies of complex traits have uncovered only a small number of risk markers explaining a small fraction of heritability and adding little improvement to disease risk prediction. Standard single marker methods may lack power in selecting informative markers or estimating effects. Most existing methods also typically do not account for non-linearity. Identifying markers with weak signals and estimating their joint effects among many non-informative markers remains challenging. One potential approach is to group markers based on biological knowledge such as gene structure. If markers in a group tend to have similar effects, proper usage of the group structure could improve power and efficiency in estimation. We propose a two-stage method relating markers to disease risk by taking advantage of known gene-set structures. Imposing a naive bayes kernel machine (KM) model, we estimate gene-set specific risk models that relate each gene-set to the outcome in stage I. The KM framework efficiently models potentially non-linear effects of predictors without requiring explicit specification of functional forms. In stage II, we aggregate information across gene-sets via a regularization procedure. Estimation and computational efficiency is further improved with kernel principle component analysis. Asymptotic results for model estimation and gene set selection are derived and numerical studies suggest that the proposed procedure could outperform existing procedures for constructing genetic risk models.

Correcting for bias in the selection and validation of informative diagnostic tests

When developing a new diagnostic test for a disease, there are often multiple candidate classifiers to choose from, and it is unclear if any will offer an improvement in performance compared with current technology. A two-stage design can be used to select a promising classifier (if one exists) in stage one for definitive validation in stage two. However, estimating the true properties of the chosen classifier is complicated by the first stage selection rules. In particular, the usual maximum likelihood estimator (MLE) that combines data from both stages will be biased high. Consequently, confidence intervals and p-values flowing from the MLE will also be incorrect. Building on the results of Pepe et al. (SIM 28:762–779), we derive the most efficient conditionally unbiased estimator and exact confidence intervals for a classifier's sensitivity in a two-stage design with arbitrary selection rules; the condition being that the trial proceeds to the validation stage. We apply our estimation strategy to data from a recent family history screening tool validation study by Walter et al. (BJGP 63:393–400) and are able to identify and successfully adjust for bias in the tool's estimated sensitivity to detect those at higher risk of breast cancer. © 2015 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

Genetics of breast cancer: a topic in evolution

A hereditary predisposition to breast cancer significantly influences screening and follow-up recommendations for high-risk women. However, in patients with a suggestive personal and/or family history, a specific predisposing gene is identified in <30% of cases. Up to 25% of hereditary cases are due to a mutation in one of the few identified rare, but highly penetrant genes (BRCA1, BRCA2, PTEN, TP53, CDH1, and STK11), which confer up to an 80% lifetime risk of breast cancer. An additional 2%-3% of cases are due to a mutation in a rare, moderate-penetrance gene (e.g. CHEK2, BRIP1, ATM, and PALB2), each associated with a twofold increase in risk. Prediction models suggest that there are unlikely to be additional yet to be identified high-penetrance genes. Investigation of common, low-penetrance alleles contributing to risk in a polygenic fashion has yielded a small number of suggestive single-nucleotide polymorphisms (SNPs), but the contributive risk of an individual SNP is quite small. Mutation testing is currently recommended for individual genes in the appropriate clinical setting where there is a high index of suspicion for a specific mutated gene or syndrome. Next-generation sequencing offers a new venue for risk assessment. At the present time, there are clear clinical guidelines for individuals with a mutation in a high-penetrance gene. Otherwise, standard models are used to predict an individual's lifetime risk by clinical and family history rather than genomic information.

Prognostic factors for breast cancer and their use in the clinical setting

Breast cancer is the second leading cause of cancer deaths in US women today. This year, approximately 216,000 US women will be diagnosed with invasive breast cancer and another 60,000 with in situ disease. Numerous factors can quantify individual risks for breast cancer, guide therapy and predict outcome. This review focuses on the clinical, pathologic, molecular and genetic prognostic tools available for use in patients with breast cancer, and their impact on clinical decisions and treatment selection.

Using a state cancer registry to recruit young breast cancer survivors and high-risk relatives: protocol of a randomized trial testing the efficacy of a targeted versus a tailored intervention to increase breast cancer screening

Background

The Michigan Prevention Research Center, the University of Michigan Schools of Nursing, Public Health, and Medicine, and the Michigan Department of Community Health propose a multidisciplinary academic-clinical practice three-year project to increase breast cancer screening among young breast cancer survivors and their cancer-free female relatives at greatest risk for breast cancer.

Methods/design

The study has three specific aims: 1) Identify and survey 3,000 young breast cancer survivors (diagnosed at 20–45 years old) regarding their breast cancer screening utilization. 2) Identify and survey survivors’ high-risk relatives regarding their breast cancer screening utilization. 3) Test two versions (Targeted vs. Enhanced Tailored) of an intervention to increase breast cancer screening among survivors and relatives. Following approval by human subjects review boards, 3,000 young breast cancer survivors will be identified through the Michigan Cancer Registry and mailed an invitation letter and a baseline survey. The baseline survey will obtain information on the survivors’: a) current breast cancer screening status and use of genetic counseling; b) perceived barriers and facilitators to screening; c) family health history. Based on the family history information provided by survivors, we will identify up to two high-risk relatives per survivor. Young breast cancer survivors will be mailed consent forms and baseline surveys to distribute to their selected high-risk relatives. Relatives’ baseline survey will obtain information on their: a) current breast cancer screening status and use of genetic counseling; and b) perceived barriers and facilitators to screening. Young breast cancer survivors and high-risk relatives will be randomized as a family unit to receive two versions of an intervention aiming to increase breast cancer screening and use of cancer genetic services. A follow-up survey will be mailed 9 months after the intervention to survivors and high-risk relatives to evaluate the efficacy of each intervention version on: a) use of breast cancer screening and genetic counseling; b) perceived barriers and facilitators to screening; c) self-efficacy in utilizing cancer genetic and screening services; d) family support related to screening; e) knowledge of breast cancer genetics; and f) satisfaction with the intervention.

Discussion

The study will enhance efforts of the state of Michigan surrounding cancer prevention, control, and public health genomics.

Trial registration

NCT01612338

Testing for improvement in prediction model performance

Authors have proposed new methodology in recent years for evaluating the improvement in prediction performance gained by adding a new predictor, Y, to a risk model containing a set of baseline predictors, X, for a binary outcome D. We prove theoretically that null hypotheses concerning no improvement in performance are equivalent to the simple null hypothesis that Y is not a risk factor when controlling for X, H0 : P(D = 1 | X,Y ) = P(D = 1 | X). Therefore, testing for improvement in prediction performance is redundant if Y has already been shown to be a risk factor. We also investigate properties of tests through simulation studies, focusing on the change in the area under the ROC curve (AUC). An unexpected finding is that standard testing procedures that do not adjust for variability in estimated regression coefficients are extremely conservative. This may explain why the AUC is widely considered insensitive to improvements in prediction performance and suggests that the problem of insensitivity has to do with use of invalid procedures for inference rather than with the measure itself. To avoid redundant testing and use of potentially problematic methods for inference, we recommend that hypothesis testing for no improvement be limited to evaluation of Y as a risk factor, for which methods are well developed and widely available. Analyses of measures of prediction performance should focus on estimation rather than on testing for no improvement in performance.

Positive and negative affect, depression, and cognitive processes in the Cognition in the Study of Tamoxifen and Raloxifene (Co-STAR) Trial

OBJECTIVES

This study examined the relationship between positive and negative affect, depressive symptoms, and cognitive performance.

METHODS

The sample consisted of 1479 non-demented, postmenopausal women (mean age = 67 years) at increased risk of breast cancer enrolled in the National Surgical Adjuvant Breast and Bowel Project's Study of Tamoxifen and Raloxifene. At each annual visit, women completed a standardized neuropsychological battery and self-report measures of affect and depression. Data from three visits were used in linear mixed models for repeated measures using likelihood ratio tests. Separate analyses were performed to relate positive/negative affect and depression to each cognitive measure.

RESULTS

Higher positive affect was associated with better letter fluency (p = .006) and category fluency (p < .0001). Higher negative affect was associated with worse global cognitive function (p < .0001), verbal memory (CVLT List B; p = .002), and spatial ability (p < .0001). Depressive symptoms were negatively associated with verbal knowledge (p = .004), figural memory (p < .0001), and verbal memory (p's ≤ .0001).

DISCUSSION

Findings are consistent with some prior research demonstrating a link between positive affect and increased verbal fluency and between depressive symptoms and decreased memory. The most novel finding shows that negative affect is related to decreased global cognition and visuospatial ability. Overall, this research in a large, longitudinal sample supports the notion that positive affect is related to increases and negative affect to decreases in performance on distinct cognitive measures.

Can the Gail model increase the predictive value of a positive mammogram in a European population screening setting? Results from a Spanish cohort

AIMS OF THE STUDY

The Gail Model (GM) is the most well-known model to assess the individual risk of breast cancer (BC). Although its discriminatory accuracy is low in the clinical context, its usefulness in the screening setting is not well known. The aim of this study is to assess the utility of the GM in a European screening program.

METHODS

Retrospective cohort study of 2200 reassessed women with information on the GM available in a BC screening program in Barcelona, Spain. The 5 year-risk of BC applying the GM right after the screening mammogram was compared first with the actual woman's risk of BC in the same screening round and second with the BC risk during the next 5 years.

RESULTS

The curves of BC Gail risk overlapped for women with and without BC, both in the same screening episode as well as 5 years afterward. Overall sensitivity and specificity in the same screening episode were 22.3 and 86.5%, respectively, and 46.2 and 72.1% 5 years afterward. ROC curves were barely over the diagonal and the concordance statistics were 0.59 and 0.61, respectively.

CONCLUSION

The GM has very low accuracy among women with a positive mammogram result, predicting BC both in the concomitant episode and 5 years later. Our results do not encourage the use of the GM in the screening context to aid the referral decision or the type of procedures after a positive mammogram or to identify women at high risk among those with a false-positive outcome.

Recommendations for raloxifene use in daily clinical practice in the Swiss setting

BACKGROUND/AIM

Raloxifene is the first selective estrogen receptor modulator that has been approved for the treatment and prevention of osteoporosis in postmenopausal women in Europe and in the US. Although raloxifene reduces the risk of invasive breast cancer in postmenopausal women with osteoporosis and in postmenopausal women at high risk for invasive breast cancer, it is approved in that indication in the US but not in the EU. The aim was to characterize the clinical profiles of postmenopausal women expected to benefit most from therapy with raloxifene based on published scientific evidence to date.

METHODS

Key individual patient characteristics relevant to the prescription of raloxifene in daily practice were defined by a board of Swiss experts in the fields of menopause and metabolic bone diseases and linked to published scientific evidence. Consensus was reached about translating these insights into daily practice.

RESULTS

Through estrogen agonistic effects on bone, raloxifene reduces biochemical markers of bone turnover to premenopausal levels, increases bone mineral density (BMD) at the lumbar spine, proximal femur, and total body, and reduces vertebral fracture risk in women with osteopenia or osteoporosis with and without prevalent vertebral fracture. Through estrogen antagonistic effects on breast tissue, raloxifene reduces the risk of invasive estrogen-receptor positive breast cancer in postmenopausal women with osteoporosis and in postmenopausal women at high risk for invasive breast cancer. Finally, raloxifene increases the incidence of hot flushes, the risk of venous thromboembolic events, and the risk of fatal stroke in postmenopausal women at increased risk for coronary heart disease. Postmenopausal women in whom the use of raloxifene is considered can be categorized in a 2 × 2 matrix reflecting their bone status (osteopenic or osteoporotic based on their BMD T-score by dual energy X-ray absorptiometry) and their breast cancer risk (low or high based on the modified Gail model). Women at high risk of breast cancer should be considered for treatment with raloxifene.

CONCLUSION

Postmenopausal women between 50 and 70 years of age without climacteric symptoms with either osteopenia or osteoporosis should be evaluated with regard to their breast cancer risk and considered for treatment with raloxifene within the framework of its contraindications and precautions.

A case-control study on risk factors of breast cancer in China

INTRODUCTION

To screen the risk factors associated with breast cancer among Chinese women in order to evaluate the individual risk of developing breast cancer among women in China.

MATERIAL AND METHODS

A case-control study on 416 breast cancer patients and 1156 matched controls was conducted in 14 hospitals in 8 provinces of China in 2008. Controls were age- and region-matched to the cases. Clinicians conducted in-person interviews with the subjects to collect information on demographics and suspected risk factors for breast cancer that are known worldwide. Conditional logistic regression was used to derive odds ratios (OR) and 95% confidence intervals (CI) for the associations between risk factors and breast cancer.

RESULTS

Compared with matched controls, women with breast cancer were significantly more likely to have higher body mass index (BMI, OR = 4.07, 95% CI: 2.98-5.55), history of benign breast disease (BBD) biopsy (OR = 1.68, 95% CI: 1.19-2.38), older age of menarche (AOM) (OR = 1.41, 95% CI: 1.07-1.87), stress anticipation (SA), for grade 1-4, OR = 2.15, 95% CI: 1.26-3.66; for grade 5-9, OR = 3.48, 95% CI: 2.03-5.95) and menopause (OR = 2.22, 95% CI: 1.50-3.282) at the level of p < 0.05. Family history of breast cancer (FHBC) in first-degree relatives (OR = 1.66, 95% CI: 0.77-3.59) and use of oral contraceptives (OC) (OR = 1.59, 95% CI: 0.83-3.05) were associated with an increased risk of breast cancer at the level of p < 0.20.

CONCLUSIONS

Our results showed that BMI, history of BBD biopsy, older AOM, SA and menopause were associated with increased risk of breast cancer among Chinese women. The findings derived from the study provided some suggestions for population-based prevention and control of breast cancer in China.

The influence of health and lifestyle characteristics on the relation of serum 25-hydroxyvitamin D with risk of colorectal and breast cancer in postmenopausal women

The authors' objective was to discern whether lifestyle or health-related factors were confounders, effect modifiers, or irrelevant with regard to understanding observational associations of serum 25-hydroxyvitamin D (25(OH)D) with colorectal and breast cancer. The authors conducted nested case-control studies of colorectal cancer (310 cases, 310 controls) and breast cancer (1,080 cases, 1,080 controls) in the Women's Health Initiative Calcium and Vitamin D Clinical Trial (1994-2005). Case-control matching factors included age, latitude, race/ethnicity, and blood collection date. Serum 25(OH)D was assayed in baseline fasting blood. Conditional logistic regression was used to estimate odds ratios for each cancer by serum 25(OH)D concentration, comparing the relative effects of successively adding body mass index, physical activity, and other health and lifestyle characteristics particular to each cancer. In models with matching factors only, low (vs. high) serum 25(OH)D was associated with a colorectal cancer odds ratio of 2.72 (95% confidence interval (CI): 1.55, 4.77) and a breast cancer odds ratio of 1.33 (95% CI: 1.02, 1.72). In multivariate-adjusted models for colorectal cancer, the association strengthened (OR = 4.45, 95% CI: 1.96, 10.10). However, in multivariate-adjusted breast cancer models, associations were no longer significant (OR = 1.06, 95% CI: 0.78, 1.43). Adjusting for health and lifestyle characteristics has differential effects depending on the cancer site; when modeling such relations, investigators should take these factors into account.

A Perturbation Method for Inference on Regularized Regression Estimates

Analysis of high dimensional data often seeks to identify a subset of important features and assess their effects on the outcome. Traditional statistical inference procedures based on standard regression methods often fail in the presence of high-dimensional features. In recent years, regularization methods have emerged as promising tools for analyzing high dimensional data. These methods simultaneously select important features and provide stable estimation of their effects. Adaptive LASSO and SCAD for instance, give consistent and asymptotically normal estimates with oracle properties. However, in finite samples, it remains difficult to obtain interval estimators for the regression parameters. In this paper, we propose perturbation resampling based procedures to approximate the distribution of a general class of penalized parameter estimates. Our proposal, justified by asymptotic theory, provides a simple way to estimate the covariance matrix and confidence regions. Through finite sample simulations, we verify the ability of this method to give accurate inference and compare it to other widely used standard deviation and confidence interval estimates. We also illustrate our proposals with a data set used to study the association of HIV drug resistance and a large number of genetic mutations.

Representing randomness in the communication of individualized cancer risk estimates: effects on cancer risk perceptions, worry, and subjective uncertainty about risk

OBJECTIVE

To test the effect of novel representations of randomness on risk perceptions, worry, and subjective uncertainty about individualized colorectal cancer risk estimates.

METHODS

A web-based factorial experiment was conducted, in which 225 adults aged 40 years and older were provided with hypothetical individualized colorectal cancer risk estimates, using 5 different textual and visual representations varying in expressed randomness. Outcome measures were perceived cancer risk, cancer worry, and subjective uncertainty about cancer risk; the moderating effect of dispositional optimism was also examined.

RESULTS

Representational format was significantly associated with subjective uncertainty about cancer risk, but not with perceived cancer risk or worry. A format using software-based animation to express randomness dynamically led to the highest subjective uncertainty, although a static visual non-random format also increased uncertainty. Dispositional optimism moderated this effect; between-format differences in uncertainty were significant only for participants with low optimism.

CONCLUSION

Representing randomness in individualized estimates of cancer risk increases subjective uncertainty about risk. A novel dynamic visual format produces the greatest effect, which is moderated by individual differences in optimism.

PRACTICE IMPLICATIONS

Novel representations of randomness may be effective in improving people's understanding of the essential uncertainty pertaining to individualized cancer risk estimates.

Problems with risk reclassification methods for evaluating prediction models

For comparing the performance of a baseline risk prediction model with one that includes an additional predictor, a risk reclassification analysis strategy has been proposed. The first step is to cross-classify risks calculated according to the 2 models for all study subjects. Summary measures including the percentage of reclassification and the percentage of correct reclassification are calculated, along with 2 reclassification calibration statistics. The author shows that interpretations of the proposed summary measures and P values are problematic. The author's recommendation is to display the reclassification table, because it shows interesting information, but to use alternative methods for summarizing and comparing model performance. The Net Reclassification Index has been suggested as one alternative method. The author argues for reporting components of the Net Reclassification Index because they are more clinically relevant than is the single numerical summary measure.

Why some women have an optimistic or a pessimistic bias about their breast cancer risk: experiences, heuristics, and knowledge of risk factors

Perceived risk to a health problem is formed by inferential rules called heuristics and by comparative judgments that assess how one's risk compares to the risk of others. The purpose of this cross-sectional, community-based survey was to examine how experiences with breast cancer, knowledge of risk factors, and specific heuristics inform risk judgments for oneself, for friends/peers, and comparative judgments for breast cancer (risk friends/peers - risk self). We recruited an English-speaking, multicultural (57% nonwhite) sample of 184 middle-aged (47 + or - 12 years old), well-educated women. Fifty percent of participants perceived that their breast cancer risk was the same as the risk of their friends/peers; 10% were pessimistic (risk friends/peers - risk self < 0), whereas 40% were optimistic (risk friends/peers - risk self > 0). Family history of breast cancer and worry informed risk judgments for oneself. The availability and cultural heuristics specific for black women informed risk judgments for friends/peers. Knowledge of risk factors and interactions of knowledge with the availability, representativeness, and simulation heuristics informed comparative judgments (risk friends/peers - risk self). We discuss cognitive mechanisms with which experiences, knowledge, and heuristics influence comparative breast cancer risk judgments. Risk communication interventions should assess knowledge deficits, contextual variables, and specific heuristics that activate differential information processing mechanisms.

A novel and automatic mammographic texture resemblance marker is an independent risk factor for breast cancer

OBJECTIVE

We investigated whether breast cancer is predicted by a breast cancer risk mammographic texture resemblance (MTR) marker.

METHODS

A previously published case-control study included 495 women of which 245 were diagnosed with breast cancer. In baseline mammograms, 2-4 years prior to diagnosis, the following mammographic parameters were analysed for relation to breast cancer risk: (C) categorical parenchymal pattern scores; (R) radiologist's percentage density, (P) computer-based percentage density; (H) computer-based breast cancer risk MTR marker; (E) computer-based hormone replacement treatment MTR marker; and (A) an aggregate of P and H.

RESULTS

Density scores, C, R, and P correlated (tau=0.3-0.6); no other pair of scores showed large (tau>0.2) correlation. For the parameters, the odds ratios of future incidence of breast cancer comparing highest to lowest categories (146 and 106 subject respectively) were C: 2.4(1.4-4.2), R: 2.4(1.4-4.1), P: 2.5(1.5-4.2), E: non-significant, H: 4.2(2.4-7.2), and A: 5.6(3.2-9.8). The AUC analysis showed a similarly increasing pattern (C: 0.58±0.02, R: 0.57±0.03, P: 0.60±0.03, H: 0.63±0.02, A: 0.66±0.02). The AUC of the aggregate marker (A) surpasses others significantly except H. HRT-MTR (E) did not significantly identify future cancers or correlate with any other marker.

CONCLUSIONS

Breast cancer risk MTR marker was independent of density scores and more predictive of risk. The hormone replacement treatment MTR marker did not identify patients at risk.

Knowledge and accuracy of perceived personal risk in underserved women who are at increased risk of breast cancer

The state of knowledge and personal risk perception among women who are underserved or racial minorities at increased risk of breast cancer (BC) who may be eligible for chemoprevention is limited. The BC knowledge and accuracy of perceived personal risk of a cross-sectional study population of such women residing in the greater Houston Texas area were assessed. The majority had below average knowledge scores and perceived risk inaccurately. The lesser educated were also less knowledgeable. Educational interventions targeted towards this population would enhance their knowledge of BC and empower them to make informed decisions about BC chemoprevention.

SI RLTD: Risk Scores and Decision Making: The Anatomy of a Decision to Reduce Breast Cancer Risk

AIM: To report the use of a risk score for risk treatment decision-making in women at risk for breast cancer in order to better understand their decision-making situation. BACKGROUND: Tamoxifen and Raloxifene are medications that have been proven to reduce the risk of breast cancer. However, women who understand their personal net benefit from Tamoxifen use chose not to take the medication. To understand this decision, the paper investigates the use of epidemiological risk information in the decision-making process for risk-reducing treatments. METHODS: The narratives of two women are analyzed as they recall their risk score and explain their decision-making process concerning participation in the Study of Tamoxifen and Raloxifene (STAR). Both in-depth interviews follow a narrative approach and were recorded in a U.S. cancer center in 2005. RESULTS: Thinking about risk by analyzing the chances of developing a disease is specific to complex decision-making situations. The associated risk-benefit analysis has to be conducted qualitatively as epidemiological risk information cannot know all details of a woman's life. In addition, a woman's decision is based on the perception of the condition as risk or as disease. Women are willing to treat risk that is perceived as disease, especially when it is based on bodily measurements on which the treatment has an effect. Women are not willing to treat a risk not perceived as disease. CONCLUSION: The net benefit of a treatment as calculated based on epidemiological data cannot easily be translated onto an individual's life. Thus, the complex experience of a woman's life at risk is highly important in decision-making situations. RELEVANCE TO CLINICAL PRACTICE: The ambiguity of statistical risk estimates should be acknowledged and the women's evaluation of her risk valued in risk treatment decision-making.

Identifying cost-effective treatment with raloxifene in postmenopausal women using risk algorithms for fractures and invasive breast cancer

INTRODUCTION

The National Osteoporosis Foundation (NOF) recommends considering treatment in women with a 20% or higher 10-year probability of a major fracture. However, raloxifene reduces both the risk of vertebral fractures and invasive breast cancer so that raloxifene treatment may be clinically appropriate and cost-effective in women who do not meet a 20% threshold risk. The aim of this study was to identify cost-effective scenarios of raloxifene treatment compared to no treatment in younger postmenopausal women at increased risk of invasive breast cancer and fracture risks below 20%.

METHOD

A micro-simulation model populated with data specific to American Caucasian women was used to quantify the costs and benefits of 5-year raloxifene treatment. The population evaluated was selected based on 10-year major fracture probability as estimated with FRAX® being below 20% and 5-year invasive breast cancer risk as estimated with the Gail risk model ranging from 1% to 5%.

RESULTS

The cost per QALY gained ranged from US $22,000 in women age 55 with 5% invasive breast cancer risk and 15-19.9% fracture probability, to $110,000 in women age 55 with 1% invasive breast cancer risk and 5-9.9% fracture probability. Raloxifene was progressively cost-effective with increasing fracture risk and invasive breast cancer risk for a given age cohort. At lower fracture risk in combination with lower invasive breast cancer risk or when no preventive raloxifene effect on invasive breast cancer was assumed, the cost-effectiveness of raloxifene worsened markedly and was not cost-effective given a willingness-to-pay of US $50,000. At fracture risk of 15-19.9% raloxifene was cost-effective also in women at lower invasive breast cancer risk.

CONCLUSIONS

Raloxifene is potentially cost-effective in cohorts of young postmenopausal women, who do not meet the suggested NOF 10-year fracture risk threshold. The cost-effectiveness is contingent on their 5-year invasive breast cancer risk. The result highlights the importance of considering a woman's full risk profile when considering anti-osteoporosis treatment.

Communication of uncertainty regarding individualized cancer risk estimates: effects and influential factors

OBJECTIVE

To examine the effects of communicating uncertainty regarding individualized colorectal cancer risk estimates and to identify factors that influence these effects.

METHODS

Two Web-based experiments were conducted, in which adults aged 40 years and older were provided with hypothetical individualized colorectal cancer risk estimates differing in the extent and representation of expressed uncertainty. The uncertainty consisted of imprecision (otherwise known as "ambiguity") of the risk estimates and was communicated using different representations of confidence intervals. Experiment 1 (n = 240) tested the effects of ambiguity (confidence interval v. point estimate) and representational format (textual v. visual) on cancer risk perceptions and worry. Potential effect modifiers, including personality type (optimism), numeracy, and the information's perceived credibility, were examined, along with the influence of communicating uncertainty on responses to comparative risk information. Experiment 2 (n = 135) tested enhanced representations of ambiguity that incorporated supplemental textual and visual depictions.

RESULTS

Communicating uncertainty led to heightened cancer-related worry in participants, exemplifying the phenomenon of "ambiguity aversion." This effect was moderated by representational format and dispositional optimism; textual (v. visual) format and low (v. high) optimism were associated with greater ambiguity aversion. However, when enhanced representations were used to communicate uncertainty, textual and visual formats showed similar effects. Both the communication of uncertainty and use of the visual format diminished the influence of comparative risk information on risk perceptions.

CONCLUSIONS

The communication of uncertainty regarding cancer risk estimates has complex effects, which include heightening cancer-related worry-consistent with ambiguity aversion-and diminishing the influence of comparative risk information on risk perceptions. These responses are influenced by representational format and personality type, and the influence of format appears to be modifiable and content dependent.

Prevention of breast cancer (part I): epidemiology, risk factors, and risk assessment tools

Advances in breast cancer research have led to declining death rates from this disease because of early detection through mammographic screening and improved therapy for breast cancer. The concept that breast cancer, in some cases, can be prevented has been explored over the last three decades. This article, part I of a two-part series, will focus on the epidemiology, the risk factors associated with breast cancer, and the available risk assessment tools, which can help define who should be considered for risk reduction strategies. Part II will focus on discussing risk reduction strategies.

Effects of tamoxifen and raloxifene on memory and other cognitive abilities: cognition in the study of tamoxifen and raloxifene

PURPOSE

To compare the effects of two selective estrogen receptor modulators, tamoxifen and raloxifene, on global and domain-specific cognitive function.

PATIENTS AND METHODS

The National Surgical Adjuvant Breast and Bowel Project's Study of Tamoxifen and Raloxifene (STAR) study was a randomized clinical trial of tamoxifen 20 mg/d or raloxifene 60 mg/d in healthy postmenopausal women at increased risk of breast cancer. The 1,498 women who were randomly assigned in STAR were age 65 years and older, were not diagnosed with dementia, and were enrolled onto the Cognition in the Study of Tamoxifen and Raloxifene (Co-STAR) trial, beginning 18 months after STAR enrollment started. A cognitive test battery modeled after the one used in the Women's Health Initiative Study of Cognitive Aging (WHISCA) was administered. Technicians were centrally trained to administer the battery and recertified every 6 months. Analyses were conducted on all participants and on 273 women who completed the first cognitive battery before they started taking their medications.

RESULTS

Overall, there were no significant differences in adjusted mean cognitive scores between the two treatment groups across visits. There were significant time effects across the three visits for some of the cognitive measures. Similar results were obtained for the subset of women with true baseline measures.

CONCLUSION

Tamoxifen and raloxifene are associated with similar patterns of cognitive function in postmenopausal women at increased risk of breast cancer. Future comparisons between these findings and patterns of cognitive function in hormone therapy and placebo groups in WHISCA should provide additional insights into the effects of tamoxifen and raloxifene on cognitive function in older women.

Laypersons' responses to the communication of uncertainty regarding cancer risk estimates

OBJECTIVE

To explore laypersons' responses to the communication of uncertainty associated with individualized cancer risk estimates and to identify reasons for individual differences in these responses.

DESIGN

A qualitative study was conducted using focus groups. Participants were informed about a new colorectal cancer risk prediction model, and presented with hypothetical individualized risk estimates using presentation formats varying in expressed uncertainty (range v. point estimate). Semistructured interviews explored participants' responses to this information.

PARTICIPANTS AND SETTING

Eight focus groups were conducted with 48 adults aged 50 to 74 residing in 2 major US metropolitan areas, Chicago, IL and Washington, DC. Purposive sampling was used to recruit participants with a high school or greater education, some familiarity with information technology, and no personal or immediate family history of cancer.

RESULTS

Participants identified several sources of uncertainty regarding cancer risk estimates, including missing data, limitations in accuracy and source credibility, and conflicting information. In comparing presentation formats, most participants reported greater worry and perceived risk with the range than with the point estimate, consistent with the phenomenon of "ambiguity aversion.'' However, others reported the opposite effect or else indifference between formats. Reasons suggested by participants' responses included individual differences in optimism and motivations to reduce feelings of vulnerability and personal lack of control. Perceptions of source credibility and risk mutability emerged as potential mediating factors.

CONCLUSIONS

Laypersons' responses to the communication of uncertainty regarding cancer risk estimates differ, and include both heightened and diminished risk perceptions. These differences may be attributable to personality, cognitive, and motivational factors.

Diffusion of breast cancer risk assessment in primary care

BACKGROUND

Physicians who provide primary care to women have the opportunity to identify patients at high risk for breast cancer who are candidates for risk reduction strategies. Our objective was to determine the prevalence and determinants of the adoption of breast cancer risk assessment by primary care physicians.

METHODS

A cross-sectional survey of a nationally representative random sample of 351 internists, family practitioners, and obstetricians-gynecologists. We used a questionnaire that assessed knowledge, attitudes, discussion of breast cancer risk, use of software to calculate breast cancer risk, and ordering of BRCA1/2 testing.

RESULTS

Eighty-eight percent of physicians reported discussing breast cancer risk at least once during the previous 12 months; 48% had ordered or referred a patient for BRCA1/2 testing; and 18% had used a software program to calculate breast cancer risk. Physicians who had used BRCA1/2 testing or discussed breast cancer risk factors were more likely to be obstetrician-gynecologists and not in a solo practice; the use of risk software was also more common among obstetrician-gynecologists but was also associated with having a family member with breast cancer and a greater knowledge about breast cancer risk. Having patients ask for risk information was associated with the discussion of risk factors but not with the other risk assessment strategies.

CONCLUSIONS

Diffusion of breast cancer risk assessment is occurring in primary care practices, with a greater adoption of BRCA1/2 testing than of the use of risk assessment software. Adoption of these strategies seems to be related to the salience of breast cancer personally (for the physician) and within the practice, as well as the size of the practice, rather than attitudes about the risk assessment methods.

Managing the risk of invasive breast cancer in women at risk for breast cancer and osteoporosis: the role of raloxifene

Raloxifene hydrochloride is a selective estrogen receptor modulator (SERM) that has antiestrogenic effects on breast and endometrial tissue and estrogenic effects on bone, lipid metabolism, and blood clotting. Raloxifene significantly improves serum lipids and serum markers of cardiovascular disease risk, but it has no significant effect on the risk of primary coronary events. A meta-analysis of randomized, double-blind, placebo-controlled trials of raloxifene for osteoporosis showed the odds of fracture risk were 0.60 (95% confidence interval [CI] = 0.49–0.74) for raloxifene 60 mg/day compared with placebo. During 8 years of follow-up in an osteoporosis trial, the raloxifene group had a 76% reduction in the incidence of invasive ER-positive breast cancer compared with the placebo group. In the STAR trial, the incidence of invasive breast cancer was 4.30 per 1000 women-years with raloxifene and 4.41 per 1000 with tamoxifen; RR = 1.02; 95% CI, 0.82–1.28. The effect of raloxifene on invasive breast cancer was, therefore, equivalent to that of tamoxifen with more favorable rates of adverse effects including uterine malignancy and clotting events. Millions of postmenopausal women could derive net benefit from raloxifene through reduced rates of fracture and invasive breast cancer.

The NSABP Study of Tamoxifen and Raloxifene (STAR) trial

In the Study of Tamoxifen and Raloxifene (STAR) trial, postmenopausal women at increased risk of breast cancer received either oral tamoxifen (20 mg/day) or raloxifene (60 mg/day) over 5 years. There were an equal number of cases of invasive breast cancer in women assigned to tamoxifen and raloxifene. There were fewer cases of noninvasive breast cancer in the tamoxifen group than in the raloxifene group (risk ratio [RR]: 1.40; 95% confidence interval [CI]: 0.98-2.02). There were more cases of uterine cancer with tamoxifen than with raloxifene (RR: 0.62; 95% CI: 0.35-1.08). Thromboembolic events occurred less often in the raloxifene group (RR: 0.70; 95% CI: 0.54-0.91) and there were fewer cataracts and cataract surgeries in the women taking raloxifene (RR: 0.79; 95% CI: 0.68-0.92). The STAR trial has shown that raloxifene is as effective as tamoxifen in reducing the risk of invasive breast cancer and has a lower risk of adverse events but a nonstatistically significant higher risk of noninvasive breast cancer. The risk of other cancers, fractures, ischemic heart disease and stroke is similar for both drugs.