Breast cancer risk assessment models: applicability to African-American women

Breast cancer risk stratification using genetic and non-genetic risk assessment tools for 246,142 women in the UK Biobank

PURPOSE

The benefit of using individual risk prediction tools to identify high-risk individuals for breast cancer (BC) screening is uncertain, despite the personalized approach of risk-based screening.

METHODS

We studied the overlap of predicted high-risk individuals among 246,142 women enrolled in the UK Biobank. Risk predictors assessed include the Gail model (Gail), BC family history (FH, binary), BC polygenic risk score (PRS), and presence of loss-of-function (LoF) variants in BC predisposition genes. Youden J-index was used to select optimal thresholds for defining high-risk.

RESULTS

In total, 147,399 were considered at high risk for developing BC within the next 2 years by at least 1 of the 4 risk prediction tools examined (Gail2-year > 0.5%: 47%, PRS2-yea r > 0.7%: 30%, FH: 6%, and LoF: 1%); 92,851 (38%) were flagged by only 1 risk predictor. The overlap between individuals flagged as high-risk because of genetic (PRS) and Gail model risk factors was 30%. The best-performing combinatorial model comprises a union of high-risk women identified by PRS, FH, and, LoF (AUC2-year [95% CI]: 62.2 [60.8 to 63.6]). Assigning individual weights to each risk prediction tool increased discriminatory ability.

CONCLUSION

Risk-based BC screening may require a multipronged approach that includes PRS, predisposition genes, FH, and other recognized risk factors.

Social and racial inequalities in diabetes and cancer in the United States

Background

Cancer and diabetes are among the leading causes of morbidity and mortality worldwide. Several studies have reported diabetes as a risk factor for developing cancer, a relationship that may be explained by associated factors shared with both diseases such as age, sex, body weight, smoking, and alcohol consumption. Social factors referred to as social determinants of health (SDOH) were shown to be associated with the risk of developing cancer and diabetes. Despite that diabetes and social factors were identified as significant determinants of cancer, no studies examined their combined effect on the risk of developing cancer. In this study, we aim at filling this gap in the literature by triangulating the association between diabetes, indices of SDOH, and the risk of developing cancer.

Methods

We have conducted a quantitative study using data from the Behavioral Risk Factor Surveillance System (BRFSS), whereby information was collected nationally from residents in the United States (US) with respect to their health-related risk behaviors, chronic health conditions, and the use of preventive services. Data analysis using weighted regressions was conducted on 389,158 study participants.

Results

Our findings indicated that diabetes is a risk factor that increases the likelihood of cancer by 13% (OR 1.13; 95%CI: 1.05-1.21). People of White race had higher odds for cancer compared to African Americans (OR 0.44; 95%CI: 0.39-0.49), Asians (OR 0.27; 95%CI: 0.20-0.38), and other races (OR 0.56; 95%CI: 0.46-0.69). The indices of SDOH that were positively associated with having cancer encompassed unemployment (OR 1.78; 95%CI: 1.59-1.99), retirement (OR 1.54; 95%CI: 1.43-1.67), higher income levels with ORs ranging between 1.16-1.38, college education (OR 1.10; 95%CI: 1.02-1.18), college graduates (OR 1.31; 95%CI: 1.21-1.40), and healthcare coverage (OR 1.44; 95%CI: 1.22-1.71). On the other hand, the indices of SDOH that were protective against having cancer were comprised of renting a home (OR 0.86; 95%CI: 0.79-0.93) and never married (OR 0.73; 95%CI: 0.65-0.81).

Conclusion

This study offers a novel social dimension for the association between diabetes and cancer that could guide setting strategies for addressing social inequities in disease prevention and access to healthcare.

Testing a deliberative democracy method with citizens of African ancestry to weigh pros and cons of targeted screening for hereditary breast and ovarian cancer risk

Background

Democratic deliberation (DD), a strategy to foster co-learning among researchers and communities, could be applied to gain informed public input on health policies relating to genomic translation.

Purpose

We evaluated the quality of DD for gaining informed community perspectives regarding targeting communities of African Ancestry (AAn) for Hereditary Breast and Ovarian Cancer (HBOC) screening in Georgia.

Methods

We audiotaped a 2.5 day conference conducted via zoom in March 2021 to examine indicators of deliberation quality based on three principles: (1) inclusivity (diverse viewpoints based on participants' demographics, cancer history, and civic engagement), (2) consideration of factual information (balanced and unbiased expert testimonies, participant perceived helpfulness), and (3) deliberation (speaking opportunities, adoption of a societal perspective on the issue, reasoned justification of ideas, and participant satisfaction).

Results

We recruited 24 participants who reflected the diversity of views and life experiences of citizens of AAn living in Georgia. The expert testimony development process we undertook for creating balanced factual information was endorsed by experts' feedback. Deliberation process evaluation showed that while participation varied (average number of statements = 24, range: 3-62), all participants contributed. Participants were able to apply expert information and take a societal perspective to deliberate on the pros and cons of targeting individuals of AAn for HBOC screening in Georgia.

Conclusions

The rigorous process of public engagement using deliberative democracy approach can successfully engage a citizenry with diverse and well-informed views, do so in a relatively short time frame and yield perspectives based on high quality discussion.

Genetic Testing and Screening Recommendations for Patients with Hereditary Breast Cancer

Professionals who specialize in breast imaging may be the first to initiate the conversation about genetic counseling with patients who have a diagnosis of premenopausal breast cancer or a strong family history of breast and ovarian cancer. Commercial genetic testing panels have gained popularity and have become more affordable in recent years. Therefore, it is imperative for radiologists to be able to provide counseling and to identify those patients who should be referred for genetic testing. The authors review the process of genetic counseling and the associated screening recommendations for patients at high and moderate risk. Ultimately, genetic test results enable appropriate patient-specific screening, which allows improvement of overall survival by early detection and timely treatment. The authors discuss pretest counseling, which involves the use of various breast cancer risk assessment tools such as the Gail and Tyrer-Cuzick models. The most common high- and moderate-risk gene mutations associated with breast cancer are also reviewed. In addition to BRCA1 and BRCA2, several high-risk genes, including TP53, PTEN, CDH1, and STK11, are discussed. Moderate-risk genes include ATM, CHEK2, and PALB2. The imaging appearances of breast cancer typically associated with each gene mutation, as well as the other associated cancers, are described. ^©RSNA, 2020 See discussion on this article by Butler (pp 937-940).

Social factors matter in cancer risk and survivorship

Greater attention to social factors, such as race/ethnicity, socioeconomic position, and others, are needed across the cancer continuum, including breast cancer, given differences in tumor biology and genetic variants have not completely explained the persistent Black/White breast cancer mortality disparity. In this commentary, we use examples in breast cancer risk assessment and survivorship to demonstrate how the failure to appropriately incorporate social factors into the design, recruitment, and analysis of research studies has resulted in missed opportunities to reduce persistent cancer disparities. The conclusion offers recommendations for how to better document and use information on social factors in cancer research and care by (1) increasing education and awareness about the importance of inclusion of social factors in clinical research; (2) improving testing and documentation of social factors by incorporating them into journal guidelines and reporting stratified results; and (3) including social factors to refine extant tools that assess cancer risk and assign cancer care. Implementing the recommended changes would enable more effective design and implementation of interventions and work toward eliminating cancer disparities by accounting for the social and environmental contexts in which cancer patients live and are treated.

Assessment of performance of the Gail model for predicting breast cancer risk: a systematic review and meta-analysis with trial sequential analysis

BACKGROUND

The Gail model has been widely used and validated with conflicting results. The current study aims to evaluate the performance of different versions of the Gail model by means of systematic review and meta-analysis with trial sequential analysis (TSA).

METHODS

Three systematic review and meta-analyses were conducted. Pooled expected-to-observed (E/O) ratio and pooled area under the curve (AUC) were calculated using the DerSimonian and Laird random-effects model. Pooled sensitivity, specificity and diagnostic odds ratio were evaluated by bivariate mixed-effects model. TSA was also conducted to determine whether the evidence was sufficient and conclusive.

RESULTS

Gail model 1 accurately predicted breast cancer risk in American women (pooled E/O = 1.03; 95% CI 0.76-1.40). The pooled E/O ratios of Caucasian-American Gail model 2 in American, European and Asian women were 0.98 (95% CI 0.91-1.06), 1.07 (95% CI 0.66-1.74) and 2.29 (95% CI 1.95-2.68), respectively. Additionally, Asian-American Gail model 2 overestimated the risk for Asian women about two times (pooled E/O = 1.82; 95% CI 1.31-2.51). TSA showed that evidence in Asian women was sufficient; nonetheless, the results in American and European women need further verification. The pooled AUCs for Gail model 1 in American and European women and Asian females were 0.55 (95% CI 0.53-0.56) and 0.75 (95% CI 0.63-0.88), respectively, and the pooled AUCs of Caucasian-American Gail model 2 for American, Asian and European females were 0.61 (95% CI 0.59-0.63), 0.55 (95% CI 0.52-0.58) and 0.58 (95% CI 0.55-0.62), respectively. The pooled sensitivity, specificity and diagnostic odds ratio of Gail model 1 were 0.63 (95% CI 0.27-0.89), 0.91 (95% CI 0.87-0.94) and 17.38 (95% CI 2.66-113.70), respectively, and the corresponding indexes of Gail model 2 were 0.35 (95% CI 0.17-0.59), 0.86 (95% CI 0.76-0.92) and 3.38 (95% CI 1.40-8.17), respectively.

CONCLUSIONS

The Gail model was more accurate in predicting the incidence of breast cancer in American and European females, while far less useful for individual-level risk prediction. Moreover, the Gail model may overestimate the risk in Asian women and the results were further validated by TSA, which is an addition to the three previous systematic review and meta-analyses.

TRIAL REGISTRATION

PROSPERO CRD42016047215 .

A comparison of cancer risk assessment and testing outcomes in patients from underserved vs. tertiary care settings

In cancer genetics, technological advances (next generation sequencing) and the expansion of genetic test options have resulted in lowered costs and increased access to genetic testing. Despite this, the majority of patients utilizing cancer genetics services lack diversity of gender, ethnicity, and socioeconomic status. Through retrospective chart review, we compared outcomes of cancer genetics consultations at a tertiary cancer center and a Federally Qualified Health Center (FQHC) (58 tertiary and 23 FQHC patients) from 2013 to 2015. The two groups differed in race, ethnicity, use of translator services, and type of insurance coverage. There were also significant differences in completeness of family history information, with more missing information about relatives in the FQHC group. In spite of these differences, genetic testing rates among those offered testing were comparable across the two groups with 74% of tertiary patients and 60% of FQHC patients completing testing. Implementation of community-based cancer genetics outreach clinics represents an opportunity to improve access to genetic counseling services, but more research is needed to develop effective counseling models for diverse patient populations.

Exposure to Bovine Leukemia Virus Is Associated with Breast Cancer: A Case-Control Study

BACKGROUND

Age, reproductive history, hormones, genetics, and lifestyle are known risk factors for breast cancer, but the agents that initiate cellular changes from normal to malignant are not understood. We previously detected bovine leukemia virus (BLV), a common oncogenic virus of cattle, in the breast epithelium of humans. The objective of this study was to determine whether the presence of BLV DNA in human mammary epithelium is associated with breast cancer.

METHODS

This was a case-control study of archival formalin fixed paraffin embedded breast tissues from 239 donors, received 2002-2008 from the Cooperative Human Tissue Network. Case definition as breast cancer versus normal (women with no history of breast cancer) was established through medical records and examination of tissues by an anatomical pathologist. Breast exposure to BLV was determined by in situ-PCR detection of a biomarker, BLV DNA, localized within mammary epithelium.

RESULTS

The frequency of BLV DNA in mammary epithelium from women with breast cancer (59%) was significantly higher than in normal controls (29%) (multiply- adjusted odds ratio = 3.07, confidence interval = 1.66-5.69, p = .0004, attributable risk = 37%). In women with premalignant breast changes the frequency of BLV DNA was intermediate (38%) between that of women with breast cancer and normal controls (p for trend < .001).

CONCLUSIONS

Among the specimens in this study, the presence of amplified BLV DNA was significantly associated with breast cancer. The odds ratio magnitude was comparable to those of well-established breast cancer risk factors related to reproductive history, hormones, and lifestyle and was exceeded only by risk factors related to genetics (familial breast cancer), high dose ionizing radiation, and age. These findings have the potential for primary and secondary prevention of breast cancer.

Applicability of the Gail model for breast cancer risk assessment in Turkish female population and evaluation of breastfeeding as a risk factor

The Gail model is considered the best available means for estimating risk of breast cancer development, but it has not yet been applied systematically and validated in Turkish female population. This study was designed to evaluate the performance of the Gail model for Turkish female population. Additionally duration of breastfeeding was examined as a possible risk factor. Our analysis included 650 patients with invasive breast carcinoma (group 1) and 640 women with negative results who had undergone a screening mammography on visiting a mammary care unit (group 2). Two groups were compared with regard to individual risk factors included in the Gail model and also duration of breastfeeding. The Gail model was used to predict 5-year risk for each woman. Age and first live birth > or =30 years were associated with an increased relative risk for breast cancer development. Age at menarche, previous breast biopsy, atypical hyperplasia, and number of first degree relatives with breast cancer were found to be non-significant. The Gail model showed 13.3% sensitivity and 92% specificity in estimating the risk of breast cancer development in Turkish women. Positive predictive value was 63%, negative predictive value was 51.9%, and validity index was 53.1%. Duration of breastfeeding was significantly longer in group 1 than 2 (median 17 vs. 13 months). The proportion of parous women with no breastfed was higher in group 1 than 2. The currently used Gail model does not seem to be an appropriate breast cancer risk assessment tool for Turkish female population.

American society of clinical oncology clinical practice guideline update on the use of pharmacologic interventions including tamoxifen, raloxifene, and aromatase inhibition for breast cancer risk reduction

PURPOSE To update the 2002 American Society of Clinical Oncology guideline on pharmacologic interventions for breast cancer (BC) risk reduction. METHODS A literature search identified relevant randomized trials published since 2002. Primary outcome of interest was BC incidence (invasive and noninvasive). Secondary outcomes included BC mortality, adverse events, and net health benefits. An expert panel reviewed the literature and developed updated consensus guidelines. Results Seventeen articles met inclusion criteria. In premenopausal women, tamoxifen for 5 years reduces the risk of BC for at least 10 years, particularly estrogen receptor (ER) -positive invasive tumors. Women < or = 50 years of age experience fewer serious side effects. Vascular and vasomotor events do not persist post-treatment across all ages. In postmenopausal women, raloxifene and tamoxifen reduce the risk of ER-positive invasive BC with equal efficacy. Raloxifene is associated with a lower risk of thromboembolic disease, benign uterine conditions, and cataracts than tamoxifen in postmenopausal women. No evidence exists establishing whether a reduction in BC risk from either agent translates into reduced BC mortality. Recommendations In women at increased risk for BC, tamoxifen (20 mg/d for 5 years) may be offered to reduce the risk of invasive ER-positive BC, with benefits for at least 10 years. In postmenopausal women, raloxifene (60 mg/d for 5 years) may also be considered. Use of aromatase inhibitors, fenretinide, or other selective estrogen receptor modulators to lower BC risk is not recommended outside of a clinical trial. Discussion of risks and benefits of preventive agents by health providers is critical to patient decision making.

BRCA1/2 in high-risk African American women with breast cancer: providing genetic testing through various recruitment strategies

BACKGROUND

Due to the disproportionate numbers of African American women affected with early onset breast cancer, we sought to investigate mutation frequency of BRCA1 and BRCA2 (BRCA1/2) in a sample of African American women, recruited through a variety of methods.

METHODS

We conducted a study investigating BRCA1/2 among 51 African American breast cancer patients with a personal or family history suggestive of hereditary predisposition to breast cancer. All individuals underwent genetic counseling and BRCA1/2 mutation analysis, through protein-truncation test on exon 11 of BRCA1 and exons 10 and 11 of BRCA2, which together account for approximately 50% of mutations observed within these genes.

RESULTS

Of the 51 women tested for BRCA1/2 mutations, 3 were identified as mutation carriers (5.9%), including 1 in BRCA1 and 2 in BRCA2. Recruitment strategies varied and included physician referrals from the Moffitt Cancer Center Breast Program (18), community-based oncologists (13), primary care physicians (3), newspaper advertisements and brochures (5), community or support group referrals (7), self/family referral through word of mouth (2), and the Florida State Cancer Registry (3).

CONCLUSIONS

Our results suggest that (1) BRCA1/2 mutations are seen in high-risk African American women with breast cancer, and (2) strategies for recruitment of African American women in studies of genetic testing for breast cancer genes have varied levels of success. Our study highlights the need for further studies in this population group.

How old are African American women when they receive their first mammogram? Results from a church-based study

African American women in the U.S. have the highest breast cancer mortality though not the highest breast cancer incidence. This high mortality rate has been attributed in part to discrepancies in screening between African American and White women. Although this gap in mammography utilization is closing, little is known about what has been and is driving the screening practices of African American women, in particular age at first mammogram. This study examined the rates of breast cancer screening in an African American community sample from eight churches in greater Baltimore, Maryland and investigated the association between various factors and age at first mammogram. Participants were 213 women ages 22-89 years. About 77% of women had ever had a mammogram. Over 40% had their first mammogram before age 40. Women who first screened before age 40 had greater odds than women who had never screened of being knowledgeable about screening guidelines, of having received a physician recommendation to screen, and of having three or more female relatives who had been screened. Women who first screened at or after age 40 were more likely to have stronger religious beliefs of health than women who never had screened. These findings suggest the importance of reinforcing factors in screening behavior for African American women and have implications for physician training and public health education about breast cancer screening. A better understanding of African American women's mammography practice including early screening is needed to reduce this population's disproportionate breast cancer mortality risk.

Incorporating ethnicity into genetic risk assessment for Alzheimer disease: the REVEAL study experience

PURPOSE

To describe how investigators in a multisite randomized clinical trial addressed scientific and ethical issues involved in creating risk models based on genetic testing for African American participants.

METHODS

The following informed our decision whether to stratify risk assessment by ethnicity: evaluation of epidemiological data, appraisal of benefits and risks of incorporating ethnicity into calculations, and feasibility of creating ethnicity-specific risk curves. Once the decision was made, risk curves were created based on data from a large, diverse study of first-degree relatives of patients with Alzheimer disease.

RESULTS

Review of epidemiological data suggested notable differences in risk between African Americans and whites and that Apolipoprotein E genotype predicts risk in both groups. Discussions about the benefits and risks of stratified risk assessments reached consensus that estimates based on data from whites should not preclude enrolling African Americans, but population-specific risk curves should be created if feasible. Risk models specific to ethnicity, gender, and Apolipoprotein E genotype were subsequently developed for the randomized clinical trial that oversampled African Americans.

CONCLUSION

The Risk Evaluation and Education for Alzheimer Disease study provides an instructive example of a process to develop risk assessment protocols that are sensitive to the implications of genetic testing for multiple ethnic groups with differing levels of risk.

Combined screening with ultrasound and mammography vs mammography alone in women at elevated risk of breast cancer

CONTEXT

Screening ultrasound may depict small, node-negative breast cancers not seen on mammography.

OBJECTIVE

To compare the diagnostic yield, defined as the proportion of women with positive screen test results and positive reference standard, and performance of screening with ultrasound plus mammography vs mammography alone in women at elevated risk of breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

From April 2004 to February 2006, 2809 women, with at least heterogeneously dense breast tissue in at least 1 quadrant, were recruited from 21 sites to undergo mammographic and physician-performed ultrasonographic examinations in randomized order by a radiologist masked to the other examination results. Reference standard was defined as a combination of pathology and 12-month follow-up and was available for 2637 (96.8%) of the 2725 eligible participants.

MAIN OUTCOME MEASURES

Diagnostic yield, sensitivity, specificity, and diagnostic accuracy (assessed by the area under the receiver operating characteristic curve) of combined mammography plus ultrasound vs mammography alone and the positive predictive value of biopsy recommendations for mammography plus ultrasound vs mammography alone.

RESULTS

Forty participants (41 breasts) were diagnosed with cancer: 8 suspicious on both ultrasound and mammography, 12 on ultrasound alone, 12 on mammography alone, and 8 participants (9 breasts) on neither. The diagnostic yield for mammography was 7.6 per 1000 women screened (20 of 2637) and increased to 11.8 per 1000 (31 of 2637) for combined mammography plus ultrasound; the supplemental yield was 4.2 per 1000 women screened (95% confidence interval [CI], 1.1-7.2 per 1000; P = .003 that supplemental yield is 0). The diagnostic accuracy for mammography was 0.78 (95% CI, 0.67-0.87) and increased to 0.91 (95% CI, 0.84-0.96) for mammography plus ultrasound (P = .003 that difference is 0). Of 12 supplemental cancers detected by ultrasound alone, 11 (92%) were invasive with a median size of 10 mm (range, 5-40 mm; mean [SE], 12.6 [3.0] mm) and 8 of the 9 lesions (89%) reported had negative nodes. The positive predictive value of biopsy recommendation after full diagnostic workup was 19 of 84 for mammography (22.6%; 95% CI, 14.2%-33%), 21 of 235 for ultrasound (8.9%, 95% CI, 5.6%-13.3%), and 31 of 276 for combined mammography plus ultrasound (11.2%; 95% CI. 7.8%-15.6%).

CONCLUSIONS

Adding a single screening ultrasound to mammography will yield an additional 1.1 to 7.2 cancers per 1000 high-risk women, but it will also substantially increase the number of false positives.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00072501.

Predicting risk of breast cancer in postmenopausal women by hormone receptor status

BACKGROUND

Strategies for estrogen receptor (ER)-positive breast cancer risk reduction in postmenopausal women require screening of large populations to identify those with potential benefit. We evaluated and attempted to improve the performance of the Breast Cancer Risk Assessment Tool (i.e., the Gail model) for estimating invasive breast cancer risk by receptor status in postmenopausal women.

METHODS

In The Women's Health Initiative cohort, breast cancer risk estimates from the Gail model and models incorporating additional or fewer risk factors and 5-year incidence of ER-positive and ER-negative invasive breast cancers were determined and compared by use of receiver operating characteristics and area under the curve (AUC) statistics. All statistical tests were two-sided.

RESULTS

Among 147,916 eligible women, 3236 were diagnosed with invasive breast cancer. The overall AUC for the Gail model was 0.58 (95% confidence interval [CI]=0.56 to 0.60). The Gail model underestimated 5-year invasive breast cancer incidence by approximately 20% (P<.001), mostly among those with a low estimated risk. Discriminatory performance was better for the risk of ER-positive cancer (AUC = 0.60, 95% CI = 0.58 to 0.62) than for the risk of ER-negative cancer (AUC = 0.50, 95% CI = 0.45 to 0.54). Age and age at menopause were statistically significantly associated with ER-positive but not ER-negative cancers (P=.05 and P=.04 for heterogeneity, respectively). For ER-positive cancers, no additional risk factors substantially improved the Gail model prediction. However, a simpler model that included only age, breast cancer in first-degree relatives, and previous breast biopsy examination performed similarly for ER-positive breast cancer prediction (AUC=0.58, 95% CI= 0.56 to 0.60); postmenopausal women who were 55 years or older with either a previous breast biopsy examination or a family history of breast cancer had a 5-year breast cancer risk of 1.8% or higher.

CONCLUSIONS

In postmenopausal women, the Gail model identified populations at increased risk for ER-positive but not ER-negative breast cancers. A model with fewer variables appears to provide a simpler approach for screening for breast cancer risk.

The Clinical Breast Care Project: an important resource in investigating environmental and genetic contributions to breast cancer in African American women

Age at diagnosis, pathological characteristics, and tumor behavior differ between African American (AAW) and Caucasian women (CW) with breast cancer, with AAW having more aggressive tumors and higher mortality rates. Although both societal and molecular contributions to these disparities have been suggested, the African American population has traditionally been under-represented in research and clinical protocols, limiting the power of epidemiologic and molecular studies to provide better understanding of disease pathogenesis in this minority population. The Clinical Breast Care Project (CBCP) has developed a large tissue and blood repository from patients undergoing treatment for breast cancer, with previous history of breast cancer, counseled in the Risk Reduction Clinic, screened by routine mammography, or undergoing elective reductive mammoplasty. Recruitment of AAW into the CBCP was successful; 25% of the 2,454 female patients were African American, including 35% disease-free, 3% high-risk, 40% benign, 8% preinvasive and 14% with invasive breast disease. More than 500 data fields regarding lifestyle choices, socioeconomic status, health history and geography were collected from all participants, and all consenting individuals provided blood specimens for genomic and proteomic studies. Tissues were collected from all patients undergoing surgical procedures using protocols that preserve the macromolecules for downstream research applications. In addition, patients were followed after diagnosis, with >85% of patients providing ongoing and updated demographic and clinical information. Thus, recruitment efforts in the CBCP have resulted in collection of well-annotated information and research-quality specimens from a large number of AAW. This unique resource will allow for the identification of biological and environmental factors associated with the identification of genetic and non-genetic factors associated with the occurrence, detection, prognosis, or survival of breast cancer in AAW.

Polymorphic variations in exon 10 of the luteinizing hormone receptor: functional consequences and associations with breast cancer

Polymorphic variation of the LHR gene may affect receptor function and accordingly may influence ovarian steroid hormone action, including steroid hormone-dependent clinical outcome. The functional effects of two single nucleotide polymorphisms (SNPs), i.e. LHR 291Asn/Ser (rs12470652) and 312Ser/Asn (rs2293275) in the biologically interesting exon 10 of the LHR gene are described. Furthermore, ethnic diversity in allele frequencies and genotype distributions of both SNPs was determined. In addition associations with breast cancer were studied in 751 breast cancer patients. In vitro transfection studies revealed altered glycosylation status and increased receptor sensitivity for the 291Ser LHR variant. No functional consequences were observed for the 312SerAsn LHR SNP. The LHR 312Asn allele was slightly more often present in two independent breast cancer patient cohorts as compared to controls (OR=1.15; p=0.03 and 1.26; p=0.001, respectively). In conclusion, although functional changes of the LHR 291Ser candidate allele were observed, no associations with breast cancer were found, while the LHR 312Asn allele can be regarded as a weak breast cancer risk allele.

Diagnostic accuracy of the Gail model in the Black Women's Health Study

The Gail model is used to predict the risk of breast cancer in women of diverse race/ethnic groups for clinical trial protocols. However, this model has only been validated in US white women. Using a nested case-control study design, we evaluated the diagnostic accuracy of the original Gail model (GM) and that of the revised Gail model algorithm for blacks/African-Americans (GM-B) in the Black Women's Health Study (BWHS). Risk profiles were derived via a self reported questionnaire at the time of enrollment into the BWHS in 1995. Biennial questionnaires were obtained from the participants to determine the incident cases of breast cancer. The study of 725 breast cancer cases and 725 controls revealed that the 5-year risk of breast cancer based on the GM ranged from 0.2% to 15.4% among cases and 0.2% to 13.6% among the controls. Based on the GM-B, the 5-year risk of breast cancer ranged from 0.2% to 8.7% among cases and 0.2% to 7.2% among the controls. The sensitivities of the GM and GM-B model with the standard cutoff of 1.7% were 17.9% (95% CI: 15.9-19.9%) and 4.1% (95% CI: 3.0-5.2), respectively. Both the original and the modified version of the Gail model underestimate the risk of developing breast cancer in African-American women. More importantly, the modified Gail Model (GM-B) does a worse job at predicting the development of breast cancer for blacks than the original model (GM).

Interest in breast cancer chemoprevention among older women

OBJECTIVES

The study aim is to describe interest in breast cancer chemoprevention among older women without a history of breast cancer and to determine whether aging-related factors such as diminished life expectancy, increasing comorbidity and medication burden attenuate chemoprevention interest.

DESIGN

Cross-sectional survey.

SETTING

University of Pennsylvania Health System.

PARTICIPANTS

Four-hundred fifty-seven community-dwelling women aged 60-65 years old who were potentially eligible for breast cancer chemoprevention according to guidelines linking risk and eligibility to age.

MEASUREMENTS

Interest in breast cancer chemoprevention, Gail model breast cancer risk, perceived breast cancer risk, breast cancer worry, self-reported health status and comorbidities, and self-reported perceived life expectancy.

RESULTS

Of 457 participants, 11.2% reported being interested in taking chemoprevention, 40.9% reported no interest, and 47.9% reported being unsure about their interest in chemoprevention. Overall, interest in chemoprevention was not associated with individual Gail model breast cancer risk. In adjusted analysis, lack of interest among high-risk women was associated with low breast cancer worry and low perceived risk. Conversely, interest in chemoprevention among low risk women was associated with greater breast cancer worry. Age-related factors hypothesized to affect chemoprevention interest, including subjective life expectancy, increased comorbidity, and number of daily medications did not attenuate chemoprevention interest.

CONCLUSION

Breast cancer worry and perceived breast cancer risk contribute to the lack of correlation between interest in breast cancer chemoprevention and objective breast cancer risk. Perceived life expectancy, increased comorbidity, and medication burden do not attenuate chemoprevention interest among older women.

Gail model for prediction of absolute risk of invasive breast cancer: independent evaluation in the Florence-European Prospective Investigation Into Cancer and Nutrition cohort

BACKGROUND

The Gail model 2 (GM) for predicting the absolute risk of invasive breast cancer has been used for counseling and to design intervention studies. Although the GM has been validated in US populations, its performance in other populations is unclear because of the wide variation in international breast cancer rates.

METHODS

We used data from a multicenter case-control study in Italy and from Italian cancer registries to develop a model (IT-GM) that uses the same risk factors as the GM. We evaluated the accuracy of the IT-GM and the GM using independent data from the Florence-European Prospective Investigation Into Cancer and Nutrition (EPIC) cohort. To assess model calibration (i.e., how well the model predicts the observed numbers of events in subsets of the population), we compared the number of expected incident breast cancers (E) predicted by these models with the number of observed incident breast cancers (O), and we computed the concordance statistic to measure discriminatory accuracy.

RESULTS

The overall E/O ratios were 0.96 (95% confidence interval [CI] = 0.84 to 1.11) and 0.93 (95% CI = 0.81 to 1.08) for the IT-GM and the GM, respectively. The IT-GM was somewhat better calibrated than GM in women younger than 50 years, but the GM was better calibrated when age at first live birth categories were considered (e.g., 20- to 24-year age-at-first-birth category E/O = 0.68, 95% CI = 0.53 to 0.94 for the IT-GM and E/O = 0.75, 95% CI = 0.58 to 1.03 for the GM). The concordance statistic was approximately 59% for both models, with 95% confidence intervals indicating that the models perform statistically significantly better than pure chance (concordance statistic of 50%).

CONCLUSIONS

There was no statistically significant evidence of miscalibration overall for either the IT-GM or the GM, and the models had equivalent discriminatory accuracy. The good performance of the IT-GM when applied on the independent data from the Florence-EPIC cohort indicates that GM can be improved for use in populations other than US populations. Our findings suggest that the Italian data may be useful for revising the GM to include additional risk factors for breast cancer.

Breast Cancer Risk and Immune Responses in Healthy Women

PURPOSE/OBJECTIVES

To summarize the findings of objective and subjective breast cancer risk assessments and their association with psychological distress and immune responses in healthy women with a family history of breast cancer.

DATA SOURCES

Published articles and book chapters.

DATA SYNTHESIS

Healthy women with a family history of breast cancer have shown decreased immune responses (i.e., low natural killer cell activity and low Th1 cytokine production), exaggerated biophysiologic reactivity to stimuli, and increased psychological distress.

CONCLUSIONS

Objective and subjective breast cancer risk is associated with impaired immune responses and exaggerated biophysiologic responses in healthy women with a family history of breast cancer. Increased psychological distress can contribute further to negative immune responses. Additional studies are warranted to substantiate and extend the findings based on more comprehensive assessments of objective and subjective breast cancer risk.

IMPLICATIONS FOR NURSING

Biophysiologic assessment is a useful approach for nurses in early identification of women at risk for breast cancer and developing appropriate strategies to reduce the risk.

Prospective breast cancer risk prediction model for women undergoing screening mammography

BACKGROUND

Risk prediction models for breast cancer can be improved by the addition of recently identified risk factors, including breast density and use of hormone therapy. We used prospective risk information to predict a diagnosis of breast cancer in a cohort of 1 million women undergoing screening mammography.

METHODS

There were 2,392,998 eligible screening mammograms from women without previously diagnosed breast cancer who had had a prior mammogram in the preceding 5 years. Within 1 year of the screening mammogram, 11,638 women were diagnosed with breast cancer. Separate logistic regression risk models were constructed for premenopausal and postmenopausal examinations by use of a stringent (P<.0001) criterion for the inclusion of risk factors. Risk models were constructed with 75% of the data and validated with the remaining 25%. Concordance of the predicted with the observed outcomes was assessed by a concordance (c) statistic after logistic regression model fit. All statistical tests were two-sided.

RESULTS

Statistically significant risk factors for breast cancer diagnosis among premenopausal women included age, breast density, family history of breast cancer, and a prior breast procedure. For postmenopausal women, the statistically significant factors included age, breast density, race, ethnicity, family history of breast cancer, a prior breast procedure, body mass index, natural menopause, hormone therapy, and a prior false-positive mammogram. The model may identify high-risk women better than the Gail model, although predictive accuracy was only moderate. The c statistics were 0.631 (95% confidence interval [CI] = 0.618 to 0.644) for premenopausal women and 0.624 (95% CI = 0.619 to 0.630) for postmenopausal women.

CONCLUSION

Breast density is a strong additional risk factor for breast cancer, although it is unknown whether reduction in breast density would reduce risk. Our risk model may be able to identify women at high risk for breast cancer for preventive interventions or more intensive surveillance.

Disparities in Genetic Testing: Thinking Outside the BRCA Box

The impact of predictive genetic testing on cancer care can be measured by the increased demand for and utilization of genetic services as well as in the progress made in reducing cancer risks in known mutation carriers. Nonetheless, differential access to and utilization of genetic counseling and cancer predisposition testing among underserved racial and ethnic minorities compared with the white population has led to growing health care disparities in clinical cancer genetics that are only beginning to be addressed. Furthermore, deficiencies in the utility of genetic testing in underserved populations as a result of limited testing experience and in the effectiveness of risk-reducing interventions compound access and knowledge-base disparities. The recent literature on racial/ethnic health care disparities is briefly reviewed, and is followed by a discussion of the current limitations of risk assessment and genetic testing outside of white populations. The importance of expanded testing in underserved populations is emphasized.

Barriers to minority participation in breast carcinoma prevention trials

BACKGROUND

Breast carcinoma prevention trials must recruit large cohorts of women who have an above-average risk of developing breast carcinoma. Recruitment for the Study of Tamoxifen and Raloxifene (STAR) trial required volunteers to complete a risk assessment questionnaire form (RAF). Women whose estimated risk of developing breast carcinoma in the next 5 years was > or = 1.67% based on the Gail model were invited to participate in STAR. Less than 4% of participants in the previously conducted P1 (tamoxifen vs. placebo) trial were minority women. We, therefore, studied barriers to minority participation in STAR among black, white, and Hispanic women who completed an RAF.

METHODS

The authors analyzed the association of Gail model risk factors, education, and insurance with race/ethnicity using chi-square tests and two-sided P values. They developed logistic regression models of trial eligibility, controlling for the Gail model risk factors, education, and insurance status.

RESULTS

Among 823 women who completed an RAF, white women were 10 times as likely as Hispanic women and 45 times as likely as black women to be eligible for STAR. Age at first birth (P = 0.04), having an affected first-degree relative (P < 0.0001), having had a biopsy (P < 0.0001), education (P < 0.0001), and insurance status (P < 0.0001) varied by race/ethnicity. All variables except insurance status were associated with eligibility when race was excluded from the model. In a model that included race/ethnicity, the same factors remained statistically significant.

CONCLUSIONS

These findings suggested that both the race/ethnicity adjustment and socioeconomic factors were barriers to eligibility for and contribute to low minority participation in breast cancer prevention trials.

Strengths and limitations of breast cancer risk assessment

PURPOSE/OBJECTIVES

To evaluate current definitions of breast cancer risk and breast cancer risk assessment models, including the Gail, Claus, and BRCAPRO models, and discuss potential markers to enhance and standardize individual risk assessment.

DATA SOURCES

Published articles, conference proceedings, and textbooks.

DATA SYNTHESIS

Defining high risk for breast cancer development is explored, and options for high-risk women are discussed. The risk factors frequently used for risk evaluation, including age, age at menarche, age at first live birth, past history of breast biopsy, family history of breast cancer, and the presence of atypical hyperplasia, are reviewed.

CONCLUSIONS

Current models of breast cancer risk assessment are limited. Exploring the progression from healthy tissue to malignancy through techniques such as fine needle aspiration, ductal lavage, and nipple aspiration may lead to more precise individualized risk prediction.

IMPLICATIONS FOR NURSING

More accurate information regarding personal breast cancer risk is necessary. Oncology nurses may facilitate the use of appropriate tools that provide the most individualized risk assessment.

Clinical genetic counselling for familial cancers requires reliable data on familial cancer risks and general action plans

Familial cancer clustering, without obvious heritability, poses a major challenge for current cancer risk assessment and management. Reliable determination of familial risks for cancer is important for clinical genetic counselling, but medically verified data on familial risks for many malignancies have been limited. However, the nationwide Swedish Family-Cancer Database allows a reliable characterisation of familial risk for all major neoplasms. Even though alert genetic counsellors and certainly clinical cancer geneticists will consider familial cancer clustering in their purview, the standard medical referral systems, which have already been shown to be poor in capturing and referring families at high risk for heritable cancers, are unlikely to ascertain familial aggregations of other cancers that are not known to belong to an inherited cancer syndrome. The data will be helpful in implementing evidence based guidelines for helping the general medical system to ascertain and refer even familial cancer clusters to cancer genetics professionals.

Retinoic Acid Receptor- 2 Promoter Methylation in Random Periareolar Fine Needle Aspiration

Methylation of the retinoic acid receptor-beta2 (RARbeta2) P2 promoter is hypothesized to be an important mechanism for loss of RARbeta2 function during early mammary carcinogenesis. The frequency of RARbeta2 P2 methylation was tested in (a) 16 early stage breast cancers and (b) 67 random periareolar fine needle aspiration (RPFNA) samples obtained from 38 asymptomatic women who were at increased risk for breast cancer. Risk was defined as either (a) 5-year Gail risk calculation > or = 1.7%; (b) prior biopsy exhibiting atypical hyperplasia, lobular carcinoma in situ, or ductal carcinoma in situ; or (c) known BRCA1/2 mutation carrier. RARbeta2 P2 promoter methylation was assessed at two regions, M3 (-51 to 162 bp) and M4 (104-251 bp). In early stage cancers, M4 methylation was observed in 11 of 16 (69%) cases; in RPFNA samples, methylation was present at M3 and M4 in 28 of 56 (50%) and 19 of 56 (38%) cases, respectively. RPFNAs were stratified for cytologic atypia using the Masood cytology index. The distribution of RARbeta2 P2 promoter methylation was reported as a function of increased cytologic abnormality. Methylation at both M3 and M4 was observed in (a) 0 of 10 (0%) of RPFNAs with Masood scores of < or = 10 (nonproliferative), (b) 3 of 20 (15%) with Masood scores of 11 to 12 (low-grade proliferative), (c) 3 of 10 (30%) with Masood scores of 13 (high-grade proliferative), and (d) 7 of 14 (50%) with Masood scores of 14 of 15 (atypia). Results from this study indicate that the RARbeta2 P2 promoter is frequently methylated (69%) in primary breast cancers and shows a positive association with increasing cytologic abnormality in RPFNA.

The Swedish family-cancer database: update, application to colorectal cancer and clinical relevance

The Swedish Family-Cancer Database has been used for almost 10 years in the study of familial risks at all common sites. In the present paper we describe some main features of version VI of this Database, assembled in 2004. This update included all Swedes born in 1932 and later (offspring) with their biological parents, a total of 10.5 million individuals. Cancer cases were retrieved from the Swedish Cancer Registry from 1958-2002, including over 1.2 million first and multiple primary cancers and in situ tumours. Compared to previous versions, only 6.0% of deceased offspring with a cancer diagnosis lack any parental information. We show one application of the Database in the study of familial risks in colorectal adenocarcinoma, with defined age-group and anatomic site specific analyses. Familial standardized incidence ratios (SIRs) were determined for offspring when parents or sibling were diagnosed with colon or rectal cancer. As a novel finding it was shown that risks for siblings were higher than those for offspring of affected parents. The excess risk was limited to colon cancer and particularly to right-sided colon cancer. The SIRs for colon cancer in age matched populations were 2.58 when parents were probands and 3.81 when siblings were probands; for right-sided colon cancer the SIRs were 3.66 and 7.53, respectively. Thus the familial excess (SIR-1.00) was more than two fold higher for right-sided colon cancer. Colon and rectal cancers appeared to be distinguished between high-penetrant and recessive conditions that only affect the colon, whereas low-penetrant familial effects are shared by the two sites. Epidemiological studies can be used to generate clinical estimates for familial risk, conditioned on numbers of affected family members and their ages of onset. Useful risk estimates have been developed for familial breast and prostate cancers. Reliable risk estimates for other cancers should also be seriously considered for routine clinical recommendations, because practically all cancers show a familial effect and the risks are high for some of the rare neoplasms. The implementation of a unified management plan for familial cancers at large will be a major challenge to the clinical genetic counselling community.

A Prospective Study of Perceived Susceptibility to Breast Cancer and Nonadherence to Mammography Screening Guidelines in African American and White Women Ages 40 to 79 Years

This prospective study examined the influence of perceived susceptibility to breast cancer on nonadherence to recommended mammography screening guidelines. The study population included 1,229 African American and White women ages 40 to 79 years who obtained an index mammography screening examination at one of five urban hospitals in Connecticut between October 1996 and January 1998. Information on perceived susceptibility to breast cancer and on multiple covariates was obtained by telephone interview on average 1.5 months after the index screening. Subsequent adherence to mammography screening guidelines was ascertained by follow-up interview on average 29 months after the index exam. Across race, age, and family breast cancer history, women who believed that their susceptibility was high (i.e., “very likely” to develop breast cancer) were less likely to adhere to screening guidelines than women who believed that their susceptibility was moderate [adjusted odds ratio (OR), 2.83; 95% confidence interval (CI), 1.51-5.30], but the effect was stronger in older women. Women ages 40 to 49 years (but not ages 50-79 years) who believed that their susceptibility was low (i.e., “not likely” or “a little likely” to develop breast cancer) were also less likely to adhere to guidelines than those who reported moderate susceptibility (adjusted OR, 3.07; 95% CI, 1.66-5.68, and adjusted OR, 2.78; 95% CI, 1.63-4.73). In contrast to most previous studies that found a positive linear relationship between perceived susceptibility to breast cancer and mammography screening, these findings suggest a more complex relationship that should be considered when developing interventions to improve adherence to mammography screening guidelines.

Contribution of three components to individual cancer risk predicting breast cancer risk in Italy

We used data from a multicentre case-control study conducted in Italy between 1991 and 1994 on over 2500 cases of breast cancer and a comparable number of controls, and estimates of breast cancer incidence in Italy to compute individual breast cancer risk for Italian women. The estimated probabilities between age 50 and 80 ranged from approximately 5% (for a woman with no family history and low modifiable risk profile) to about 30% (for a woman with young family history and high modifiable risk) on the basis of various women's baseline characteristics. Expected numbers of breast cancer cases using the present model were compared with those based on the USA Gail model, and with the observed ones in the comparison group of the Italian Tamoxifen Trial. These show a closer agreement between the observed and the expected total numbers of breast cancers than the USA Gail model. Thus, the Gail model can be improved for use in other populations by using estimates of incidence and risk which are more appropriate to the target population.

Should Tamoxifen Be Used in Breast Cancer Prevention?

Breast cancer is the most commonly diagnosed cancer in women. The risk of developing breast cancer can be lowered by maintaining a healthy bodyweight and avoiding long-term use of combined estrogen and progestogen replacement after menopause. However, many women are at an increased risk of developing breast cancer secondary to age, early menarche, a family history of breast cancer or a personal history of benign breast disease. These women may now be offered tamoxifen as a chemoprevention therapy. Five years of tamoxifen treatment results in a reduction in the relative risk of developing estrogen receptor-positive breast cancer of 48%. This benefit outweighs the risk of tamoxifen-related adverse events for many healthy women. However, the benefit-risk ratio of tamoxifen chemoprevention varies for individual women. The randomized clinical trials evaluating standard-dose tamoxifen versus placebo as chemoprevention therapy are reviewed and analyzed to determine which particular women are most likely to benefit and least likely to experience a tamoxifen-related adverse event. Tamoxifen decreases the risk of breast cancer associated with aging, having a first-degree relative with disease, and a personal diagnosis of atypical ductal hyperplasia or lobular carcinoma in situ. Women who have had a hysterectomy and are at low risk of a thromboembolic event have a decreased risk of adverse effects associated with tamoxifen therapy. The strengths and weaknesses of the Gail model (frequently used to assess an individual's risk of developing invasive breast cancer over the next 5 years) are highlighted. A method for assessing the benefit-risk ratio for an individual woman is presented. Alternative breast cancer chemoprevention strategies are considered, including the use of aromatase inhibitors. This article discusses the pros and cons of these various preventive therapies and concludes that at this time, tamoxifen remains the gold standard for breast cancer prevention.

The Impact of a Family History of Breast Cancer on Screening Practices and Attitudes in Low-Income, Rural, African American Women

BACKGROUND

Women with a family history of breast cancer are at increased risk for developing cancer and, therefore, might be expected to engage in early detection practices more actively than women without a family history. Alternatively, women with a family history may avoid thinking about cancer and have attitudes and practices that do not promote early detection.

METHODS

This study examined breast cancer attitudes and practices among African American women aged >or=50 who had not had a mammogram in the last 2 years.

RESULTS

Phone survey data from 320 female clients of low-income, rural primary care clinics (91% African American) indicated that 15% self-reported a family history of breast cancer (FH(+)). Half of the FH(+) women did not know their relative risk of developing breast cancer. Of those providing a risk estimate, 67% perceived themselves at low risk compared with other women their age. Perceived relative risk was comparable between FH(+) and FH(-) women. Further, FH(+) women did not indicate greater worry about breast cancer, nor did they have more accurate knowledge of mammography recommendations than FH(-) women. Two thirds of FH(+) women had never had a mammogram. Monthly breast self-examination did not differ between FH(+) and FH(-) women.

CONCLUSIONS

Thus, neither knowledge of a positive family history nor perceived relative risk of breast cancer was associated with either increased or decreased early detection practices among these low-income, rural, African American women who have underused mammography. Furthermore, a substantial proportion of FH(+) women had not ever participated in screening mammography. Interventions to increase mammography rates in this population of underusers are indicated.