Prevalence of BRCA mutations and founder effect in high-risk Hispanic families

Awareness, perceptions, and provider recommendation related to genetic testing for hereditary breast cancer risk among at-risk Hispanic women: similarities and variations by sub-ethnicity

This study explored awareness of risk factors for hereditary breast and ovarian cancer (HBOC), awareness, knowledge and concerns about genetic testing, and preference for how to have genetic testing recommended by a care provider among at-risk Hispanic women. Differences in these factors among Mexican, Cuban, and Puerto Rican women were also examined. Women with a personal or family history of breast or ovarian cancer from the Tampa Bay Area participated in a qualitative interview (N = 53). Data were analyzed using a combination of open and axial coding with a grounded theory approach. Study participants in all groups reported: being aware that family history was a breast cancer risk factor, limited knowledge of genetic testing, fear of test results, concerns about children's risks, and no physician referral for genetic testing. Noteworthy sub-ethnic differences included preferences for physician recommendation and information about genetic testing. This study provides important preliminary information about areas related to HBOC that require additional education in the Hispanic community as a whole and by sub-ethnicity.

A pilot study of hereditary breast and ovarian knowledge among a multiethnic group of Hispanic women with a personal or family history of cancer

PURPOSE

To examine knowledge about hereditary breast and ovarian cancer (HBOC) among Mexican, Puerto Rican, and Cuban women.

METHODS

Women (age range, 18-65 years) with a personal or family history of breast or ovarian cancer were recruited to a mixed methods study using community-based approaches. Fifty-three women participated in the study: 16 Mexicans, 20 Puerto Ricans, and 17 Cubans. The majority of women (64.2%) were born outside the United States. All questions were interviewer administered in Spanish or English. HBOC knowledge was measured using an 11-item instrument developed by the National Center for Human Genome Research. We evaluated whether differences in knowledge varied as a function of Hispanic subethnicity, demographic characteristics, and medical and acculturation characteristics using a series of one-way analysis of variances.

RESULTS

The percentage of correct responses on the knowledge instrument ranged from 9.4% to 73.6% (median number of correct responses = 45%). Knowledge did not significantly differ by Hispanic subethnicity (p = 0.51). Exploratory analysis revealed lower knowledge in women with a personal history of cancer (p = 0.03).

CONCLUSION

Our study provides important information about characteristics associated with lower levels of knowledge and specific areas related to HBOC where additional education may be warranted in the Hispanic community.

Exploring attitudes, beliefs, and communication preferences of Latino community members regarding BRCA1/2 mutation testing and preventive strategies

PURPOSE

To inform development of a culturally sensitive hereditary breast and ovarian cancer communication initiative and related clinical genetic services.

METHODS

Five focus groups were conducted with 51 female and male Latinos. Educational materials were designed to communicate information about hereditary breast or ovarian cancer and availability of relevant clinical services or prevention strategies. Focus groups explored participants' knowledge, attitudes, and beliefs about hereditary breast and ovarian cancer, BRCA1/2 testing, and communication preferences for hereditary breast and ovarian cancer health messages.

RESULTS

Overall, awareness of familial breast and ovarian cancer and availability of genetic risk assessment was low. Once informed, participants held favorable attitudes toward risk assessment and counseling services. Critical themes of the research highlighted the need to provide bilingual media products and use of a variety of strategies to increase awareness about hereditary cancer risk and availability of clinical genetic services. Important barriers were identified regarding family cancer history communication and cancer prevention services. Strategies were suggested for communicating cancer genetic information to increase awareness and overcome these barriers; these included both targeted and tailored approaches.

CONCLUSION

This research suggests that cancer genetic communication efforts should consider community and cultural perspectives as well as health care access issues before widespread implementation.

BRCA1 and BRCA2 mutations across race and ethnicity: distribution and clinical implications

PURPOSE OF REVIEW

To summarize evidence on the prevalence and spectrum of BRCA1 and BRCA2 BRCA1/2 mutations across racial and ethnic groups and discuss implications for clinical practice.

RECENT FINDINGS

The prevalence of BRCA1/2 mutations is comparable among breast cancer patients of African, Asian, white, and Hispanic descent: approximately 1-4% per gene. Among ovarian cancer patients in North America, BRCA1/2 mutations are present in 13-15%. Between racial/ethnic groups, there are important differences in the spectrum of BRCA1 compared with BRCA2 mutations, in BRCA1/2 variants of uncertain significance, and in the accuracy of clinical models that predict BRCA1/2 mutation carriage.

SUMMARY

Given the significant prevalence of BRCA1/2 mutations across race/ethnicity, there is a need to expand and customize genetic counseling, genetic testing, and follow-up care for members of all racial/ethnic groups.

Interest and beliefs about BRCA genetic counseling among at-risk Latinas in New York City

BACKGROUND

Latinas are less likely to use genetic services (counseling and testing) for hereditary breast and/or ovarian cancer risk compared to other ethnic groups. Meanwhile, little is known about barriers to genetic counseling among Latinas at increased risk of inherited breast cancer.

METHODS

A two-phase pilot study was conducted to examine interest, barriers and beliefs about BRCA genetic counseling among at-risk Latinas in New York City and explore the potential for developing a culturally-tailored narrative educational tool for use in future studies. Phase 1 included quantitative telephone interviews (N = 15) with bilingual participants with a personal diagnosis at a young age and/or family history of breast and/or ovarian cancer. Quantitative results informed development of a narrative prototype educational presentation viewed by a subset of participants (N = 10) in Phase 2 focus groups.

RESULTS

Despite barriers, including lack of awareness/knowledge, concerns related to learning cancer risks of family members, and concerns about cost/health insurance, participants reported positive attitudes, beliefs and interest in learning about BRCA genetic counseling. Further, significant increases in knowledge were demonstrated from pre-post presentation (p = 0.04).

CONCLUSION

There is an unmet need to educate at-risk Latinas about BRCA genetic counseling. Culturally-tailored educational materials including narratives may increase knowledge about BRCA genetic counseling among this underserved group. The effectiveness of these approaches should be tested in future research with larger samples.

BRCA1 and BRCA2 germline mutation analysis among Indian women from south India: identification of four novel mutations and high-frequency occurrence of 185delAG mutation

Mutations in the BRCA1 and BRCA2 genes profoundly increase the risk of developing breast and/or ovarian cancer among women. To explore the contribution of BRCA1 and BRCA2 mutations in the development of hereditary breast cancer among Indian women, we carried out mutation analysis of the BRCA1 and BRCA2 genes in 61 breast or ovarian cancer patients from south India with a positive family history of breast and/or ovarian cancer. Mutation analysis was carried out using conformation-sensitive gel electrophoresis (CSGE) followed by sequencing. Mutations were identified in 17 patients (28.0%); 15 (24.6%) had BRCA1 mutations and two (3.28%) had BRCA2 mutations. While no specific association between BRCA1 or BRCA2 mutations with cancer type was seen, mutations were more often seen in families with ovarian cancer. While 40% (4/10) and 30.8% (4/12) of families with ovarian or breast and ovarian cancer had mutations, only 23.1% (9/39) of families with breast cancer carried mutations in the BRCA1 and BRCA2 genes. In addition, while BRCA1 mutations were found in all age groups, BRCA2 mutations were found only in the age group of < or =40 years. Of the BRCA1 mutations, there were three novel mutations (295delCA; 4213T-->A; 5267T-->G) and three mutations that have been reported earlier. Interestingly, 185delAG, a BRCA1 mutation which occurs at a very high frequency in Ashkenazi Jews, was found at a frequency of 16.4% (10/61). There was one novel mutation (4866insT) and one reported mutation in BRCA2. Thus, our study emphasizes the importance of mutation screening in familial breast and/or ovarian cancers, and the potential implications of these findings in genetic counselling and preventive therapy.

BRCA1 and BRCA2 mutations in women of different ethnicities undergoing testing for hereditary breast-ovarian cancer

BACKGROUND

In women at increased risk for breast and ovarian cancer, the identification of a mutation in breast cancer gene 1 (BRCA1) and BRCA2 has important implications for screening and prevention counseling. Uncertainty regarding the role of BRCA1 and BRCA2 testing in high-risk women from diverse ancestral backgrounds exists because of variability in prevalence estimates of deleterious (disease-associated) mutations in non-white populations. In this study, the authors examined the prevalence of BRCA1 and BRCA2 mutations in an ethnically diverse group of women who were referred for genetic testing.

METHODS

In this cross-sectional analysis, the prevalence of BRCA1 and BRCA2 mutations was assessed in a group of non-Ashkenazi Jewish women who underwent genetic testing.

RESULTS

From 1996 to 2006, 46,276 women who met study criteria underwent DNA full-sequence analysis of the BRCA1 and BRCA2 genes. Deleterious mutations were identified in 12.5% of women, and recurrent deleterious mutations (prevalence >2%) were identified in all ancestral groups. Women of non-European descent were younger (mean age, 45.9 years; standard deviation [SD], 11.6 years) than European women (mean age, 50 years; SD, 11.9 years; P < .001). Women of African (15.6%; odds ratio [OR], 1.3 [95% confidence interval (95% CI), 1.1-1.5]) and Latin American (14.8%; OR, 1.2 [95% CI, 1.1-1.4]) ancestries had a significantly higher prevalence of deleterious BRCA1 and BRCA2 mutations compared with women of Western European ancestry (12.1%), primarily because of an increased prevalence of BRCA1 mutations in those 2 groups. Non-European ethnicity was associated strongly with having a variant of uncertain significance; however, reclassification decreased variant reporting (from 12.8%-->5.9%), and women of African ancestry experienced the largest decline (58%).

CONCLUSIONS

Mutation prevalence was found to be high among women who were referred for clinical BRCA1 and BRCA2 testing, and the risk was similar across diverse ethnicities. BRCA1 and BRCA2 testing is integral to cancer risk assessment in all high-risk women.

Performance of prediction models for BRCA mutation carriage in three racial/ethnic groups: findings from the Northern California Breast Cancer Family Registry

PURPOSE

Patients with early-onset breast and/or ovarian cancer frequently wish to know if they inherited a mutation in one of the cancer susceptibility genes, BRCA1 or BRCA2. Accurate carrier prediction models are needed to target costly testing. Two widely used models, BRCAPRO and BOADICEA, were developed using data from non-Hispanic Whites (NHW), but their accuracies have not been evaluated in other racial/ethnic populations.

METHODS

We evaluated the BRCAPRO and BOADICEA models in a population-based series of African American, Hispanic, and NHW breast cancer patients tested for BRCA1 and BRCA2 mutations. We assessed model calibration by evaluating observed versus predicted mutations and attribute diagrams, and model discrimination using areas under the receiver operating characteristic curves.

RESULTS

Both models were well-calibrated within each racial/ethnic group, with some exceptions. BOADICEA overpredicted mutations in African Americans and older NHWs, and BRCAPRO underpredicted in Hispanics. In all racial/ethnic groups, the models overpredicted in cases whose personal and family histories indicated >80% probability of carriage. The two models showed similar discrimination in each racial/ethnic group, discriminating least well in Hispanics. For example, BRCAPRO's areas under the receiver operating characteristic curves were 83% (95% confidence interval, 63-93%) for NHWs, compared with 74% (59-85%) for African Americans and 58% (45-70%) for Hispanics.

CONCLUSIONS

The poor performance of the model for Hispanics may be due to model misspecification in this racial/ethnic group. However, it may also reflect racial/ethnic differences in the distributions of personal and family histories among breast cancer cases in the Northern California population.

Differences in estrogen receptor subtype according to family history of breast cancer among Hispanic, but not non-Hispanic White women

BACKGROUND

Pathologic differences have been reported among breast tumors when comparing ethnic populations. Limited research has been done to evaluate the ethnic-specific relationships between breast cancer risk factors and the pathologic features of breast tumors.

METHODS

Given that genetic variation may contribute to ethnic-related etiologic differences in breast cancer, we hypothesized that tumor characteristics differ according to family history of breast cancer among Hispanic and non-Hispanic White (NHW) women. Logistic regression models were used to compute odds ratios (OR) and 95% confidence intervals (95% CI) to assess this relationship in the population-based, case-control 4-Corners Breast Cancer Study (1,537 cases and 2,452 controls).

RESULTS

Among Hispanic women, having a family history was associated with a 2.7-fold increased risk of estrogen receptor (ER) negative (95% CI, 1.59-4.44), but not ER positive tumors (OR, 1.04; 95% CI, 0.71-1.54) when compared with women without breast cancer. In contrast, there was an increased risk for ER positive (OR, 1.89; 95% CI, 1.50-2.38) and a marginally significant increased risk for ER negative tumors (OR, 1.41; 95% CI, 0.92-2.17) among NHW women. When comparing tumor characteristics among invasive cases, those with a family history also had a significantly higher proportion of ER negative tumors among Hispanics (39.2% versus 25.8%; P=0.02), but not among NHWs (16.3% versus 21.1%; P=0.13).

CONCLUSIONS

These results may reflect ethnic-specific predisposing genetic factors that promote the development of specific breast tumor subtypes, and emphasize the importance of evaluating the relationship between breast cancer risk factors and breast tumor subtypes among different ethnic populations.

Family history and age at onset of breast cancer in Hispanic and non-Hispanic white women

OBJECTIVES

To evaluate the association between family history of breast cancer and breast cancer risk among Hispanic and non-Hispanic white (NHW) women.

METHODS

Logistic regression models were used to compute unadjusted and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) using data collected from the 4-Corners Breast Cancer Study, a population-based case-control study of breast cancer conducted in the Southwest United States (3,074 NHW and 1,647 Hispanic women).

RESULTS

The association between family history of breast cancer and early-onset breast cancer risk differs among NHW and Hispanic women. Among women <50 years old, having a family history of breast cancer was associated with a greater increase in risk among NHWs, with an OR of 2.34 (95% CI: 1.64-3.35) when compared to an OR of 1.32 (95% CI: 0.82-2.19) for Hispanics. This difference in risk was not observed among women 50 years and older, with an OR of 1.69 (95% CI: 1.34-2.13) for NHW and 1.47 (95% CI: 1.03-2.10) for Hispanics.

CONCLUSIONS

Family history of breast cancer poses a greater risk for early-onset breast cancers among NHW when compared to Hispanic women and may reflect ethnic differences in certain predisposing genetic factors that promote breast cancer development.

Performance of BRCA1/2 mutation prediction models in Asian Americans

PURPOSE

There are established differences in breast cancer epidemiology between Asian and white individuals, but little is known about hereditary breast cancer in Asian populations. Although increasing numbers of Asian individuals are clinically tested for BRCA1/2 mutations, it is not known whether computer models that predict mutations work accurately in Asian individuals. We compared the performance in Asian and white individuals of two widely used BRCA1/2 mutation prediction models, BRCAPRO and Myriad II.

PATIENTS AND METHODS

We evaluated BRCAPRO and Myriad II in 200 Asian individuals and a matched control group of 200 white individuals who were tested for BRCA1/2 mutations at four cancer genetics clinics, by comparing numbers of observed versus predicted mutation carriers and by evaluating area under the receiver operating characteristic curve (AUC) for each model.

RESULTS

BRCAPRO and Myriad II accurately predicted the number of white BRCA1/2 mutation carriers (25 observed v 24 predicted by BRCAPRO; 25 predicted by Myriad II, P > or = .69), but underpredicted Asian carriers by two-fold (49 observed v 25 predicted by BRCAPRO; 26 predicted by Myriad II; P < or = 3 x 10(-7)). For BRCAPRO, this racial difference reflects substantial underprediction of Asian BRCA2 mutation carriers (26 observed v 4 predicted; P = 1 x 10(-30)); for Myriad II, separate mutation predictions were not available. For both models, AUCs were nonsignificantly lower in Asian than white individuals, suggesting less accurate discrimination between Asian carriers and noncarriers.

CONCLUSION

Both BRCAPRO and Myriad II underestimated the proportion of BRCA1/2 mutation carriers, and discriminated carriers from noncarriers less well, in Asian compared with white individuals.

Acculturation and familiarity with, attitudes towards and beliefs about genetic testing for cancer risk within Latinas in East Harlem, New York City

Recent research underscores the need for increasing use of genetic testing for cancer risk in Latinos. This study examined the influence of acculturation on attitudes, beliefs about and familiarity with genetic testing for cancer risk in a community-based sample of Latinas in East Harlem, New York City (N = 103). Multivariate linear regression models analyzed the relationship of acculturation to: (1) familiarity (2) perceived benefits (3) perceived barriers and (4) concerns about abuses of genetic testing for cancer risk. Controlling for sociodemographic factors, results revealed that with increasing acculturation Latinas were more familiar with genetic testing (beta = 1.62, SE = 0.72, p = 0.03), more likely to cite perceived benefits (beta = 1.67, SE = 0.79, p = 0.04), and less likely to report perceived barriers related to genetic testing (beta = -2.76, SE = 1.64, p = 0.10). Study results may help inform the development of culturally-appropriate health education outreach materials and programs targeted to increase awareness, knowledge and understanding about genetic testing for cancer risk within Latinas.

Allelic imbalance in BRCA1 and BRCA2 gene expression is associated with an increased breast cancer risk

The contribution of BRCA1 and BRCA2 to familial and non-familial forms of breast cancer has been difficult to accurately estimate because of the myriad of potential genetic and epigenetic mechanisms that can ultimately influence their expression and involvement in cellular activities. As one of these potential mechanisms, we investigated whether allelic imbalance (AI) of BRCA1 or BRCA2 expression was associated with an increased risk of developing breast cancer. By developing a quantitative approach utilizing allele-specific real-time PCR, we first evaluated AI caused by nonsense-mediated mRNA decay in patients with frameshift mutations in BRCA1 and BRCA2. We next measured AI for BRCA1 and BRCA2 in lymphocytes from three groups: familial breast cancer patients, non-familial breast cancer patients and age-matched cancer-free females. The AI ratios of BRCA1, but not BRCA2, in the lymphocytes from familial breast cancer patients were found to be significantly increased as compared to cancer-free women (BRCA1: 0.424 versus 0.211, P = 0.00001; BRCA2: 0.206 versus 0.172, P = 0.38). Similarly, the AI ratios were greater for BRCA1 and BRCA2 in the lymphocytes of non-familial breast cancer cases versus controls (BRCA1: 0.353, P = 0.002; BRCA2: 0.267, P = 0.03). Furthermore, the distribution of under-expressed alleles between cancer-free controls and familial cases was significantly different for both BRCA1 and BRCA2 gene expression (P < 0.02 and P < 0.02, respectively). In conclusion, we have found that AI affecting BRCA1 and to a lesser extent BRCA2 may contribute to both familial and non-familial forms of breast cancer.

Breast cancer risk associated with BRCA1 and BRCA2 in diverse populations

Germline mutations in the BRCA1 or BRCA2 tumour-suppressor genes are strong predictors of breast and/or ovarian cancer development. The contribution of these mutations to breast cancer risk within any specific population is a function of both their prevalence and their penetrance. Mutation prevalence varies among ethnic groups and may be influenced by founder mutations. Penetrance can be influenced by mutation-specific phenotypes and the potential modifying effects of the patient's own genetic and environmental background. Although estimates of both mutation prevalence and mutation penetrance rates are inconsistent and occasionally controversial, understanding them is crucial for providing accurate risk information to each patient.

Founder mutations in BRCA1 and BRCA2 genes

BRCA1 and BRCA2 germline mutations contribute to a significant number of familial and hereditary breast and/or ovarian cancers. The proportion of high-risk families with breast and/or ovarian cancer cases due to mutations in these tumor suppressor genes varies widely among populations. In some population, a wide spectrum of different mutations in both genes are present, whereas in other groups specific mutations in BRCA1 and BRCA2 have been reported with high frequency. Most of these mutations are prevalent in restricted populations as consequence of a founder effect. The comparison of haplotypes between families with the same mutation can distinguish whether high-frequency alleles derive from an older or more recent single mutational event or whether they have arisen independently more than once. Here, we review some of the most well-known and significant examples of founder mutations in BRCA genes found in European and non-European populations. In conclusion, the identification of the ethnic group of families undergoing genetic counseling enables the geneticist and oncologist to make more specific choices, leading to simplify the clinical approach to genetic testing carried out on members of high-risk families. Futhermore, the high frequency of founder mutations, allowing to analyze a large number of cases, might provide accurate information regarding their penetrance.

BRCA1 and BRCA2 genetic testing in Hispanic patients: mutation prevalence and evaluation of the BRCAPRO risk assessment model

PURPOSE

The BRCAPRO model, used to predict a family's likelihood of carrying a BRCA1 or BRCA2 mutation, was designed using mutation frequencies of white and Ashkenazi Jewish populations, and may not be applicable to other populations. BRCAPRO was recently validated in African Americans, although has yet to be examined in Hispanics. This retrospective study reports the mutation frequency and spectrum of BRCA1 and BRCA2 mutations in a Hispanic population and evaluates the BRCAPRO model in Hispanics.

PATIENTS AND METHODS

A descriptive analysis of mutation frequency and spectrum was performed for Hispanic patients who underwent BRCA1 and BRCA2 genetic testing at a single institution. For comparative analysis of the BRCAPRO risk model, Hispanic patients who underwent comprehensive analysis were compared with white controls using area under the receiver operating characteristic curves (AUROC).

RESULTS

Fourteen Hispanic individuals who underwent comprehensive analysis were identified to carry a mutation in BRCA1 or BRCA2 (17.9%; 95% CI, 10.2% to 28.3%) and seven individuals had a variant of uncertain significance (9.0%; 95% CI, 12.0% to 30.8%). A total of eight different mutations and three variants were observed within the entire Hispanic population. When evaluating the performance of the BRCAPRO model, the AUROC for Hispanics was 0.774 (95% CI, 0.63 to 0.90), compared with the AUROC of 0.770 (95% CI, 0.65 to 0.89) for whites.

CONCLUSION

Deleterious BRCA1 and BRCA2 mutations occur at considerable frequency within the Hispanic population, many of which have been identified previously in other ethnic populations. The BRCAPRO model appears to perform equally well in Hispanics as in whites.

Triple negative breast carcinoma and the basal phenotype: from expression profiling to clinical practice

Triple negative breast carcinomas (TNBCs) are a group of primary breast tumors with aggressive clinical behavior. Most TNBCs possess a basal phenotype (BP) and show varying degrees of basal cytokeratin and myoepithelial marker expression. The importance of recognizing these tumors came to light largely as the result of gene expression profiling studies that categorized breast cancer into 3 major groups. Two of these groups are defined by their respective expression of estrogen receptor and HER2. TNBCs represent a third group and are defined by negativity for hormone receptors and HER2. TNBCs currently lack effective targeted therapies and are frequently resistant to standard chemotherapeutic regimens. These tumors tend to occur in premenopausal women and members of specific ethnic groups and a subset are associated with heritable BRCA1 mutations. For patients with sporadic TNBCs and BP tumors, BRCA1 dysfunction seems to play a major role in the development and progression of disease. The pathologist's role in the diagnosis and characterization of TNBCs and BP tumors is currently being defined as we are acquiring knowledge of the biologic and genetic underpinnings that drive this heterogeneous group of diseases. This review will provide a historical prospective on TNBCs and tumors that express basal cytokeratins and myoepithelial makers. Additionally, we will discuss the molecular biologic, genetic and pathologic aspects of these tumors. Guidelines will be provided on how to best approach the diagnosis of these cases and on what input pathologists should provide clinicians to help develop optimal therapeutic and preventative strategies against this aggressive group of breast cancers.

Evidence for common ancestral origin of a recurring BRCA1 genomic rearrangement identified in high-risk Hispanic families

BACKGROUND

Large rearrangements account for 8% to 15% of deleterious BRCA mutations, although none have been characterized previously in individuals of Mexican ancestry.

METHODS

DNA from 106 Hispanic patients without an identifiable BRCA mutation by exonic sequence analysis was subjected to multiplexed quantitative differential PCR. One case of Native American and African American ancestry was identified via multiplex ligation-dependent probe amplification. Long-range PCR was used to confirm deletion events and to clone and sequence genomic breakpoints. Splicing patterns were derived by sequencing cDNA from reverse transcription-PCR of lymphoblastoid cell line RNA. Haplotype analysis was conducted for recurrent mutations.

RESULTS

The same deletion of BRCA1 exons 9 through 12 was identified in five unrelated families. Long-range PCR and sequencing indicated a deletion event of 14.7 kb. A 3-primer PCR assay was designed based on the deletion breakpoints, identified within an AluSp element in intron 8 and an AluSx element in intron 12. Haplotype analysis confirmed common ancestry. Analysis of cDNA showed direct splicing of exons 8 to 13, resulting in a frameshift mutation and predicted truncation of the BRCA1 protein.

CONCLUSIONS

We identified and characterized a novel large BRCA1 deletion in five unrelated families-four of Mexican ancestry and one of African and Native American ancestry, suggesting the possibility of founder effect of Amerindian or Mestizo origin. This BRCA1 rearrangement was detected in 3.8% (4 of 106) of BRCA sequence-negative Hispanic families. An assay for this mutation should be considered for sequence-negative high-risk Hispanic patients.

Determination of cancer risk associated with germ line BRCA1 missense variants by functional analysis

Germ line inactivating mutations in BRCA1 confer susceptibility for breast and ovarian cancer. However, the relevance of the many missense changes in the gene for which the effect on protein function is unknown remains unclear. Determination of which variants are causally associated with cancer is important for assessment of individual risk. We used a functional assay that measures the transactivation activity of BRCA1 in combination with analysis of protein modeling based on the structure of BRCA1 BRCT domains. In addition, the information generated was interpreted in light of genetic data. We determined the predicted cancer association of 22 BRCA1 variants and verified that the common polymorphism S1613G has no effect on BRCA1 function, even when combined with other rare variants. We estimated the specificity and sensitivity of the assay, and by meta-analysis of 47 variants, we show that variants with <45% of wild-type activity can be classified as deleterious whereas variants with >50% can be classified as neutral. In conclusion, we did functional and structure-based analyses on a large series of BRCA1 missense variants and defined a tentative threshold activity for the classification missense variants. By interpreting the validated functional data in light of additional clinical and structural evidence, we conclude that it is possible to classify all missense variants in the BRCA1 COOH-terminal region. These results bring functional assays for BRCA1 closer to clinical applicability.

Beliefs and interest in cancer risk in an underserved Latino cohort

OBJECTIVE

To measure beliefs about cancer causation, cancer screening behaviors, access to information about and resources for cancer screening, and interest in cancer genetics services in two underserved predominantly Latino communities.

METHODS

An anonymous survey, in both English and Spanish, was distributed at the registration desk to all attendees of selected general medicine clinics in two underserved healthcare systems.

RESULTS

There were a total of 312 respondents, representing 98% of eligible candidates. The reported data focus on 75.3% (n=235) of Latino respondents; mean age 43 years; 78% female; 72% less than high school education. Heredity was perceived as the most frequent cause of cancer, after smoking. Only 37% knew of free cancer screening programs. Over 85% expressed interest in obtaining information about personal cancer risk and motivation to participate in cancer genetics services.

CONCLUSIONS

The results of this survey demonstrate an awareness of heredity as a potential cause of cancer. The observed high level of interest in cancer genetics services suggests the acceptability of cancer genetics services in this predominantly underserved Latino population. Furthermore, cancer genetics services would likely augment awareness and utilization of available cancer screening services in the community.

An overview of ethnicity and assessment of family history in primary care settings

PURPOSE

To discuss the importance of and the nurse practitioner's (NP's) role in the assessment of ethnicity/family of origin in conducting a multigenerational family history in primary care settings.

DATA SOURCES

A review of the literature on past research results addressing racial and ethnic disparities and current articles from scientific journals exploring the relationship between race and genetics. Web sites were from the National Institutes of Health, the Human Genome Research Institute, the National Cancer Institute, and the Health and Human Services Minority Health and Disparities report.

CONCLUSIONS

The family history has received renewed interest due to the sequencing of the human genome. A multigenerational family history is an important first step in screening for a multitude of disorders impacted by genetic susceptibility, shared environments, and common behaviors. Assessment of the patient's ethnicity/family of origin is an integral part of the multigenerational family history, particularly in the diagnosis of chronic diseases and the assessment of risks for genetic disorders. The multigenerational family history is important in diagnosis, predictive genetic testing, disease prevention, and health promotion. Challenges facing NPs and the utilization of a multigenerational family history in the current U.S. health system include (a) training clinicians on the correct assessment and utilization of a multigenerational family history, (b) assessment of the subtleties of ethnicity and identifying multiple ethnic groups within a family, (c) collection of the family history in a manner that is sensitive to the cultural beliefs of individuals, and (d) avoidance of stereotyping.

IMPLICATIONS FOR PRACTICE

Significant advances in genetics and genetic testing requires that NPs be well versed in collecting and interpreting a multigenerational family history to include assessment of the patient/family's ethnicity/family of origin. The ability to effectively conduct and evaluate the individual's and family's health risk through a multigenerational family history will be important in diagnosis, health promotion, disease prevention, and the determination for genetic counseling referral and predictive testing when appropriate. Assessment of risk and prevention of disease is also important in reducing health disparities.

If We Build It … Will They Come? – Establishing a Cancer Genetics Services Clinic for an Underserved Predominantly Latina Cohort

BACKGROUND

Cancer genetic counseling and testing is a standard of care option for appropriate families and can identify individuals at increased risk prior to diagnosis, when prevention or detection strategies are most effective. Despite documented efficacy of cancer risk reduction in high-risk individuals, underserved and minority individuals have a disproportionate cancer burden and limited access to genetic counseling.

METHODS

A needs assessment survey documented gaps in knowledge and interest in prevention. Satellite clinics were established at two indigent healthcare systems. Cancer genetics CME lectures were conducted and referral guidelines disseminated to clinicians who referred patients for counseling.

RESULTS

An increase in clinician knowledge was demonstrated post-CME and reflected by quality referrals. Eighty-eight percent of patients kept their appointments. In the predominantly Latina(6) (n=77) clinic population, 71.4% were affected with cancer, and 17 mutation positive families were identified. Preliminary data shows a positive impact on patients' motivation and behavior. The majority has expressed satisfaction and reduction in anxiety.

CONCLUSIONS

This study demonstrates feasibility and acceptability of cancer genetics services in this population, suggesting the potential to reduce cancer morbidity in underserved, high-risk families.

High proportion of BRCA1/2 founder mutations in Hispanic breast/ovarian cancer families from Colombia

In South America, a high proportion of the population is of Hispanic origin with an important representation in Colombia. Since nothing is known about the contribution of BRCA1 and BRCA2 germline mutations to hereditary breast/ovarian cancer in the Hispanic population from Colombia, we conducted the first study of 53 breast/ovarian cancer families from this country. Comprehensive BRCA mutation screening was performed using a range of techniques, including DHPLC, SSCP, and PTT, followed by DNA sequencing analysis. Thirteen deleterious germline mutations (24.5%) were identified in 53 families, comprising eight in BRCA1 and five in BRCA2. The two recurrent BRCA1 mutations, 3450 delCAAG and A1708E, accounted for 100% of all BRCA1 mutations identified in this cohort and the recurrent 3034 delACAA BRCA2 mutation for 40% of all BRCA2 mutations. Haplotype analyses suggested that each of these mutations has arisen from a common ancestor. The prevalence of BRCA1 or BRCA2 mutations was 50% in multiple case breast cancer families, and was 33% for the breast-ovarian cancer families. Our findings show that BRCA mutations account for a substantial proportion of hereditary breast/ovarian cancer in Colombia. The spectrum of mutations differed completely to that previously reported in Hispanic families of predominantly Mexican origin from Southern California [1] suggesting that specific genetic risk assessment strategies for the different Hispanic populations in South America and in the United States need to be developed.

Ashkenazi Jews and breast cancer: the consequences of linking ethnic identity to genetic disease

We explored the advantages and disadvantages of using ethnic categories in genetic research. With the discovery that certain breast cancer gene mutations appeared to be more prevalent in Ashkenazi Jews, breast cancer researchers moved their focus from high-risk families to ethnicity. The concept of Ashkenazi Jews as genetically unique, a legacy of Tay-Sachs disease research and a particular reading of history, shaped this new approach even as methodological imprecision and new genetic and historical research challenged it. Our findings cast doubt on the accuracy and desirability of linking ethnic groups to genetic disease. Such linkages exaggerate genetic differences among ethnic groups and lead to unequal access to testing and therapy.

Evaluation of BRCA1 and BRCA2 mutation prevalence, risk prediction models and a multistep testing approach in French-Canadian families with high risk of breast and ovarian cancer

BACKGROUND AND OBJECTIVE

In clinical settings with fixed resources allocated to predictive genetic testing for high-risk cancer predisposition genes, optimal strategies for mutation screening programmes are critically important. These depend on the mutation spectrum found in the population under consideration and the frequency of mutations detected as a function of the personal and family history of cancer, which are both affected by the presence of founder mutations and demographic characteristics of the underlying population. The results of multistep genetic testing for mutations in BRCA1 or BRCA2 in a large series of families with breast cancer in the French-Canadian population of Quebec, Canada are reported.

METHODS

A total of 256 high-risk families were ascertained from regional familial cancer clinics throughout the province of Quebec. Initially, families were tested for a panel of specific mutations known to occur in this population. Families in which no mutation was identified were then comprehensively tested. Three algorithms to predict the presence of mutations were evaluated, including the prevalence tables provided by Myriad Genetics Laboratories, the Manchester Scoring System and a logistic regression approach based on the data from this study.

RESULTS

8 of the 15 distinct mutations found in 62 BRCA1/BRCA2-positive families had never been previously reported in this population, whereas 82% carried 1 of the 4 mutations currently observed in > or =2 families. In the subset of 191 families in which at least 1 affected individual was tested, 29% carried a mutation. Of these 27 BRCA1-positive and 29 BRCA2-positive families, 48 (86%) were found to harbour a mutation detected by the initial test. Among the remaining 143 inconclusive families, all 8 families found to have a mutation after complete sequencing had Manchester Scores > or =18. The logistic regression and Manchester Scores provided equal predictive power, and both were significantly better than the Myriad Genetics Laboratories prevalence tables (p<0.001). A threshold of Manchester Score > or =18 provided an overall sensitivity of 86% and a specificity of 82%, with a positive predictive value of 66% in this population.

CONCLUSION

In this population, a testing strategy with an initial test using a panel of reported recurrent mutations, followed by full sequencing in families with Manchester Scores > or =18, represents an efficient test in terms of overall cost and sensitivity.

The Impact of Acculturation on Awareness of Genetic Testing for Increased Cancer Risk among Hispanics in the Year 2000 National Health Interview Survey

Previous studies suggest disparities in use of preventive cancer services among U.S. Hispanics are partly explained by knowledge and access factors. One area of emerging interest is uptake of genetic counseling and testing services by underserved populations. This study aims to estimate the percentage of Hispanics in five ethnic subgroups who are aware of genetic testing for inherited cancer risk, and to assess the influence of acculturation factors primarily related to language on test awareness. Weighted data from 4,313 Hispanic respondents (age >25 years) in the year 2000 National Health Interview Survey were analyzed. Overall, 20.6% of Hispanics had heard of genetic testing for cancer risk, with percentages highest among Puerto Ricans (27.3%) and lowest among Mexicans (14.3%). Completing the interview in Spanish and English [odds ratio (OR), 0.52; 95% confidence interval (95% CI), 0.35-0.78], or only Spanish (OR, 0.60; 95% CI, 0.42-0.86), was inversely associated with test awareness (reference group, only English). Having an intermediate (OR, 0.66; 95% CI, 0.48-0.90) or low (OR, 0.63; 95% CI, 0.39-1.01) level of English language preference was also inversely associated (reference, high level) whereas being born outside the United States was weakly associated (OR, 0.80; 95% CI, 0.57-1.11). Estimates were adjusted for age, education, ethnicity, parents' cancer history, health care access, and selected health behaviors and beliefs. Results of this national survey indicate that acculturation factors related to language may affect cancer genetic test awareness in Hispanics. These factors must be taken into account when informing individuals about the role of genetics in cancer risk and providing cancer genetic health services.