The risk of developing invasive breast cancer in Hispanic women

The Risk of Developing Invasive Breast Cancer in Hispanic

Women

A Look Across Hispanic Subgroups

Matthew P. Banegas, PhD, MPH1,2; Mei Leng, MS3; Barry I. Graubard, PhD4; and Leo S. Morales, MD, PhD, MPH1,2,5

BACKGROUND: Current evidence on breast cancer among US Hispanic women indicates a significant public health threat, although

few studies have assessed the heterogeneity in breast cancer risk among Hispanics of different origin. METHODS: The 2000 and

2005 National Health Interview Survey Cancer Control Modules were used to examine the Breast Cancer Risk Assessment Tool

(BCRAT) 5-year risk and lifetime risk of invasive breast cancer among Mexican/Mexican American, Puerto Rican, Cuban/Cuban Ameri-

can, Dominican (Republic), Central/South American, Other Hispanic, and non-Hispanic white (NHW) women ages 35 to 84 years. Mul-

tiple linear regression models were used to compare the BCRAT 5-year and lifetime breast cancer risk between 1) Hispanics and

NHWs and 2) Hispanic subgroups. RESULTS: Hispanic women had significantly lower mean BCRAT 5-year and lifetime breast cancer

risk compared with NHW women (P < .001). Among Hispanic subgroups, Cuban/Cuban Americans had a higher BCRAT 5-year risk

(P < .05), whereas Dominicans had a higher lifetime risk (P < .001) compared with Mexican/Mexican Americans. Approximately 2.6%

of Hispanic women were at high risk for breast cancer (BCRAT 5-year risk �1.67%), ranging from 1% of Central/South Americans to

3.7% of Puerto Ricans; few Hispanics (0.2%) had a lifetime risk �20%. CONCLUSIONS: The current findings indicate that Hispanic

women have a significantly lower risk of breast cancer compared with NHW women, although the risk according to BCRAT differed

significantly between specific Hispanic subgroups. We provide estimates of the number of US Hispanic women from six subgroups

who may be eligible for prophylactic breast cancer chemoprevention. The authors concluded that future studies should further

investigate the heterogeneity in breast cancer risk and risk factors between Hispanic women of different origins. Cancer

2013;119:1373-80.VC 2012 American Cancer Society.

KEYWORDS: breast cancer, risk assessment, Hispanic/Latino, Breast Cancer Risk Assessment Tool.

INTRODUCTIONBreast cancer is a significant public health threat to Hispanic women in the United States, as it represents the most fre-quently diagnosed cancer and the leading cause of cancer-related death in this population.1 Although recent trends indi-cate a declining incidence of breast cancer among US women, breast cancer incidence has declined at a slower rate for USHispanic women2; furthermore, these findings are consistent across stages of diagnosis with the rate at which large breastcancer tumors are diagnosed among Hispanic women not declining significantly.3 Despite having a low incidence rate ofbreast cancer, Hispanic women are more likely to present with advanced breast cancer at diagnosis4,5 and are more likelyto die from breast cancer compared with non-Hispanic white women.6-8

Although these data reflect the burden of breast cancer among Hispanic women as a whole, it is also important tounderstand the diversity of this population and the extent to which the risk of breast cancer varies between Hispanicwomen of different national origins and backgrounds. US Hispanic women are characterized by differences in geneticancestry and in behavioral and lifestyle practices, which may lead to differences in their risk of developing breast cancer.2

However, the heterogeneity in breast cancer risk among women in different Hispanic subgroups has not been well defined.To address this gap, the objective of the current study was to assess the distribution of breast cancer risk among His-

panic women from six subgroups: Mexican/Mexican Americans, Puerto Ricans, Cubans/Cuban Americans, Dominicans,Central/South Americans, and Other Hispanics. By using data from the 2000 and 2005 National Health Interview Survey(NHIS) Cancer Control Modules (CCMs), we assessed the 5-year and lifetime risk of developing invasive breast canceramong US Hispanic women (n ¼ 3386) and non-Hispanic white women (n ¼ 16,131) based on the National Cancer

DOI: 10.1002/cncr.27896, Received: July 27, 2012; Revised: September 1, 2012; Accepted: October 8, 2012, Published online December 7, 2012 in Wiley Online

Library (wileyonlinelibrary.com)

Corresponding author: Matthew P. Banegas, PhD, MPH, Health Services and Economics Branch, Applied Research Program, Division of Cancer Control and

Population Sciences, National Cancer Institute, 6130 Executive Boulevard, Room 4019B, Bethesda, MD 20892; Fax: (301) 435-3710, [email protected]

1School of Public Health, Department of Health Services, University of Washington, Seattle, Washington; 2Public Health Sciences Division, Fred Hutchinson Cancer

Research Center, Seattle, Washington; 3Department of General Internal Medicine and Health Services Research, University of California-Los Angeles, Los Angeles,

California; 4Divisions of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland; 5Group Health Research Institute, Seattle, Washington.

The authors would like to thank Dr. Mitchell Gail and Dr. Jeremy Steeves for their input on the manuscript.

Cancer April 1, 2013 1373

Original Article

Institute (NCI) Breast Cancer Risk Assessment Tool(BCRAT). Evaluating breast cancer risk among differentHispanic subgroups has the potential to improve ourunderstanding of the impact of breast cancer in thisdiverse population and to identify those women from spe-cific Hispanic subgroups who may benefit from strategiesto reduce the risk of breast cancer.

MATERIALS AND METHODSInformation about the study design, data source, andstudy population was previously described in detail.9 Inbrief, the NHIS is an annual, cross-sectional householdsurvey that obtains information on the health of the civil-ian, noninstitutionalized population residing in theUnited States.10 The NHIS is a multistage, cluster proba-bility sample survey design that over samples both His-panic and black populations. Furthermore, the NHIScore questionnaire is comprised of 4 components: house-hold, family, sample adult, and sample child, with addi-tional supplement questionnaires on specific topics,including: cancer control. The CCM, which was designedand funded by the NCI, was administered in 2000 and2005 and collected information on diet and nutrition,physical activity, tobacco use, cancer screening, genetictesting, family history, and other risk factors related tocancer. The 2000 and 2005 NHIS CCMs collected datafrom 1 randomly sampled adult aged �18 years fromeach sampled family and household, resulting in 32,374and 31,321 sampled adults, respectively. For the currentstudy, we analyzed data on Hispanic women (n ¼ 3386)and non-Hispanic white women (n ¼ 16,131) ages 35 to84 years who had no history of breast cancer or mastec-tomy (unilateral or bilateral) and who completed theCCMmodule.

Key Measures

Absolute risk of developing breast cancer

Absolute risk is defined as the probability that anindividual with a given set of risk factors who is free of thedisease of interest at age x (eg, age 40 years) will developthe disease before a subsequent age x þ y (eg, age 45years), where y is the time interval over which risk is pro-jected11 (eg, 5 years). The NCI BCRAT12,13 (available at:http://www.cancer.gov/bcrisktool/; [accessed July 1,2012]) estimates a woman’s absolute risk of developinginvasive breast cancer over a specific time based on age,age at first live birth, age at menarche, number of first-degree relatives with breast cancer, number of breast biop-sies, and presence of atypical hyperplasia (note that infor-mation on atypical hyperplasia is unavailable in the

NHIS). When information on a particular risk factor ismissing, BCRAT imputes the lowest category of risk. Weused the BCRAT to estimate participants’ absolute risk ofinvasive breast cancer over two periods: 1) 5-year risk, cal-culated from the age at interview to the hypothetical agethat a woman would attain if she survived for 5 years afterthe date of the interview; and 2) lifetime risk, calculatedfrom the age at interview to the hypothetical age that awoman would attain if she survived to age 90 years.

Hispanic origin

The 2000 and 2005 NHIS collected self-reporteddata on race and Hispanic origin (based on country of ori-gin and ancestry), which we used to categorize women asnon-Hispanic white or Hispanic. Hispanic women werefurther divided into six distinct subgroups: Mexican/Mex-ican Americans, Cubans/Cuban Americans, PuertoRicans, Dominicans, Central or South Americans, andother Latin Americans/other Spanish/multiple Hispanics(referred to as ‘‘Other Hispanics’’).

Explanatory variables

We included several variables in the analyses thatprevious research indicates may be associated with the riskof developing breast cancer.14-22 Sociodemographic varia-bles included marital status (married/living with intimatepartner or other), education (less than high school gradu-ate, high school graduate/General Education Develop-ment [GED], or more than high school), and federalpoverty level (<100%, 100%-200%, or �200%). Twovariables were included as proxies for access to health care:usual source of care (yes or no) and insurance status (pri-vate, public, or uninsured). We also included informationon county of birth (US born or foreign born), years in theUnited States (<5 years, 5-9 years, or�10 years), and lan-guage most often spoken (mostly/only Spanish, Spanish/English about the same, or mostly/only English), andbody mass index (BMI) (normal, BMI <25 kg/m2; over-weight, BMI 25-30 kg/m2; or obese, BMI>30 kg/m2).

Statistical Analyses

Data from the 2000 and 2005 NHIS were pooled for thisanalysis. To obtain US population estimates, the observa-tions were weighted by the sample weights for each year,which were summed and divided by 2.23 The stratified,multistage cluster complex sample design of the NHISwas accounted for when calculating standard errors and95% confidence intervals.23

Descriptive statistics were used to assess participants’baseline sociodemographic, access, acculturation, andBMI characteristics. We estimated participants’ BCRAT

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1374 Cancer April 1, 2013

5-year and lifetime risk estimates and corresponding 95%confidence intervals, as previously described.12,13 Statisti-cal methods appropriate for complex samples were usedto compare the distribution of descriptive variablesbetween non-Hispanic white women and Hispanicwomen and between Hispanic subgroups including thet test, the chi-square test, and theWald F test.

Multiple linear regression models were then esti-mated for both the BCRAT 5-year and lifetime absolutebreast cancer risk estimates, separately, controlling forthe explanatory variables. For each risk estimate, 2 dif-ferent comparisons were made: 1) between Hispanicsversus non-Hispanic whites and 2) among Hispanicsubgroups. A 3-step multiple imputation method,which was used previously in an analysis of a US-basedpopulation health survey, as previously described,24 wasused to impute poverty level, because approximately24% of the observations were missing these values.First, we estimated an ordinal logistic regression modelfor poverty level using marital status, education, andHispanic subgroup combined with country of birth/time in the United States. Second, for each individualwith missing poverty level data, we generated probabil-ity cutoff points for each category of poverty level basedon regression model coefficients. Third, we drew a ran-dom number between zero and 1 from a uniform distri-bution and compared it with the probability cutoffpoints to assign each individual to 1 category. It is note-worthy that the National Center for Health Statisticsalso generated imputed income variables for both the2000 and 2005 NHIS surveys,25 although, we used thepreviously described method for the current study.

In addition, we used a stepwise approach to theregression models using four different models. Model 1was adjusted for marital status, age, education, and federalpoverty level; Model 2 was adjusted for the Model 1 cova-riates plus usual source of care and insurance; Model 3was adjusted for Model 2 covariates plus BMI; and Model4 was adjusted for Model 3 covariates plus country of ori-gin and years in the United States. For the acculturationvariables, a composite variable was generated that com-bined county of birth (US born, foreign born) and yearsin the United States (<5 years, 5-9 years, �10 years).Bivariate analyses indicated that the language most oftenspoken was not predictive of breast cancer risk and,accordingly, was dropped from the final regression analy-ses. All computations were conducted using SAS software(version 9.2; SAS Institute Inc, Cary, NC) and SAS call-able SUDAAN (version 9.0; RTI, Research TrianglePark, NC).

RESULTS

Sociodemographic and Breast Cancer RiskFactors

The mean age of non-Hispanic white women was signifi-cantly older compared with that of Hispanic women(54.3 years vs 50.3 years, respectively; P< .001) (Table 1).Overall, a significantly greater proportion of Hispanicwomen were aged <12 years at initiation of menarche,younger at first live birth, had no family history of breastcancer, and had never received a breast biopsy comparedwith non-Hispanic white women. Further, a significantlygreater proportion of Hispanic women had less than a highschool education (46%) and had a household income thatwas<100% of the federal poverty level (21.7%) comparedwith non-Hispanic white women (11.9% and 6.8%,respectively).

Among Hispanic subgroups, Cuban/Cuban Ameri-can women had the highest mean age (56.5 years). Agreater proportion of Mexican/Mexican Americanwomen (48.3%) and Other Hispanic women (86.5%)were born in the United States, whereas Puerto Ricanwomen had the greatest proportion that spoke only/mostly Spanish (27.4%). Puerto Rican women (91.4%)and Other Hispanic women (93.8%) had the greatest pro-portion with a usual source of care, and Central/SouthAmerican women had the greatest proportion of unin-sured women (52.8%). Mexican/Mexican Americanwomen (36.4%) and Puerto Rican women (36.7%) hadthe greatest proportion of obese women among Hispanicsubgroups.

Absolute Risk of Developing Breast Cancer

Table 2 presents the mean 5-year and lifetime BCRATabsolute risk estimates of study participants. These resultsindicate that, for the Hispanic women in our study, on av-erage, the probability of developing invasive breast cancerover the next 5 years was 0.64%, and, over their lifetime,it was 5.88%, which was significantly lower than the risksfor non-Hispanic white women (1.24% and 8.63%,respectively; P < .001). Among Hispanic women,Cuban/Cuban American and Other Hispanic women hada significantly higher mean BCRAT 5-year absolute riskcompared with Mexican/Mexican American women (P<

.001). Dominican and Central/South American womenhad a significantly higher mean BCRAT lifetime absoluterisk compared with Mexican/Mexican American women(P< .001).

A significantly lower proportion of Hispanic womenwere at high risk of breast cancer compared with non-His-panic white women (P < .001) (Table 3) based on both

Breast Cancer Across Hispanic Subgroups/Banegas et al


TABLE 1. Distribution of Participant Risk Factors

Percentage of Patients

Hispanic Subgroup

Characteristic

Non-HispanicWhites,

n ¼ 16,131

TotalHispanics,n ¼ 3386

Mexicans/Mexican

Americans,n ¼ 1932

PuertoRicans,n ¼ 385

Cubans/Cuban

Americans,n ¼ 274

Dominicans,n ¼ 123

Central/South

Americans,n ¼ 468

OtherHispanics,n ¼ 204)

BCRAT risk factors

Mean age [95% CI], y 54.3

[54.1-54.3]

50.3

[49.7-50.9]a49.8

[48.9-50.6]b51

[49.5-52.4]

56.5

[54.5-58.4]

48

[45.7-50.3]

48

[46.7-49.3]

52.8

[50.2-55.5]

Age at menarche, y

<12 17.7 23.2a 22b 29.8 26.8 18.1 24.1 16.9

12-13 55.3 50 49 53.3 46.5 69.2 44.7 61.5

�14 26.9 26.8 29 16.9 26.7 12.75 31.2 21.6

Age at first live birth, yr

Nulliparous 16.1 10.8a 8.5b 11.9 22.5 10.9 12.7 9.5

<20 18.8 29.8 32.1 37.3 17.1 18.5 21.2 33.7

20-24 33.7 33.1 36.1 31.7 24.2 23.8 29.9 31.9

25-29 19.7 17.1 15.8 10.8 25.7 33.8 19.8 14.7

�30 11.6 9.5 7.5 8.2 10.5 13 16.4 10.1

No. of first-degree relatives with breast cancer

0 88.5 93.9a 93.5b 91.7 94.7 91.2 98.1 91.6

�1 11.5 6.1 6.5 8.3 5.3 8.8 1.9 8.4

No. of previous breast biopsies

0 82.3 90.6a 90.8b 88.5 94.1 94.1 90.3 87.5

�1 17.72 9.4 9.2 11.5 5.9 5.9 9.7 12.5

Acculturation factors

Years in the US

US born 95.4 37.2a 48.3b 28.8 9.2 2.1 5.3 86.5

<5 0.3 4.1 3.4 3.1 5.2 2.5 8.6 —d

5-9 0.4 7.8 6.1 3.1 9.9 14.2 18.3 0.3

�10 3.9 51 42.2 65 75.6 81.2 67.7 13.2

Language spoken

Only/mostly English 99.1 49a 48.3b 40.7 61.9 78.6 61.5 6.1

Equal English/Spanish 0.2 28 28.1 31.9 21 10.5 15.1 73.1

Only/mostly Spanish 0.7 23 23.6 27.4 17.1 10.9 23.4 20.8

Sociodemographic factors

Marital status. %

Married/living

with partner

68.8 66.1a 69.1b 55.3 63.4 51.3 68.7 64.9

Education

<HS graduate 11.9 46a 53.4b 43 34.3 57.6 35.5 19.9

HS graduate/GED 33.7 23.5 23.3 20.2 21.7 18.6 22.7 26.7

>High school 54.4 30.5 23.3 30.9 43.9 23.8 41.7 53.3

Poverty level

<100% 6.8 21.7a 24.3b 26.4 13.4 34.8 13.3 14.7

100-199% 15.7 28.2 29.7 26.7 26.6 34.6 27.1 18.7

�200% 77.4 50.1 46 46.9 60 30.5 59.7 66.6

Access

Usual source of care

Yes 93.6 83.6a 80.7b 91.4 87.3 89.7 81 93.8

Insurance

Private 59.1 43.3a 42.4b 40.4 43.4 37.9 46.1 52.8

Public 29 27 23.8 41.9 37.1 31.1 19.4 30.9

Uninsured 11.9 29.7 33.8 17.7 19.3 31 34.5 16.3

Behavioral factors

Body mass index

Normal 46.9 32.9a 29.1b 31.9 35.1 39.1 39.6 47

Overweight 29.6 34.7 34.5 31.4 43.2 39.6 33.9 31.5

Obese 23.5 32.4 36.4 36.7 21.7 21.2 26.5 21.5

Abbreviations: BCRAT, Breast Cancer Risk Assessment Tool; CI, confidence interval; GED, General Education Development.aP < .001 (2-sided t test or chi-square test comparing all Hispanics versus non-Hispanic whites;bP < .001 (2-sided Wald F test comparing Hispanic subgroups).cYears in the US indicates the number of years foreign-born individuals resided in the United States.d In this category, there were too few observations in a given cell to report.

Original Article


the BCRAT 5-year risk and lifetime risk estimates (eg,threshold values for identifying women at high-risk, asdefined by the American Society of Clinical Oncology[ASCO] and the National Comprehensive Cancer Net-work [NCCN], of �1.67% 5-year risk of invasive breastcancer and �20% lifetime risk of invasive breast cancer).Approximately 2.6% of all Hispanic women had aBCRAT 5-year absolute risk�1.67%, and only 0.2% had

a lifetime absolute risk �20%. Central/South Americanwomen had a significantly lower proportion of women athigh risk of breast cancer (1%) compared with Mexican/Mexican American women (2.7%; P < .001). AmongHispanic subgroups, few women had a BCRAT lifetimeabsolute risk �20%, and only 0.4% of Other Hispanicwomen and 0.3% of Mexican/Mexican American womenmet this high-risk threshold.

Multivariate Regression Analyses

Table 4 summarizes results from the multivariate regres-sion models, indicating that Hispanic women had signifi-cantly lower 5-year and lifetime absolute risk ofdeveloping breast cancer based on the BCRAT comparedwith non-Hispanic white women (P < .001). The mean5-year absolute risk of invasive breast cancer for Hispanicwomen was consistently lower than for non-Hispanicwhite women (difference, 0.4 percentage points; P <

.001), whereas the mean lifetime absolute risk of invasivebreast cancer for Hispanic women was approximately 2.8percentage points lower than for non-Hispanic whitewomen (P< .001).

With regard to Hispanic women, the 5-year absoluterisk of breast cancer for Cuban/Cuban American womenwas higher than the risk for Mexican/Mexican Americanwomen (P< .05). No other differences in BCRAT 5-yearabsolute risk were observed between Mexican/MexicanAmerican women and other Hispanic subgroups. Inassessing the lifetime absolute risk of breast cancer, themean risk for Dominican women was significantly higherthan the mean risk for Mexican/Mexican Americanwomen, and the difference remained significant after

TABLE 3. Estimates of the Total Number of Women at High Risk of Breast Cancer Based on Breast CancerRisk Assessment Tool 5-Year and Lifetime Absolute Risk Estimatesa

5-Year Risk �1.67% Lifetime Risk �20%

Participant Subgroup No. % [95% CI] No. % [95% CI]

Non-Hispanic whites 10,479,744 19.55 [18.84-20.26] 730,723 1.36 [1.16-1.56]

All Hispanics 171,484 2.59 [1.98-3.20]b 11,425 0.17 [0.03-0.31]b

Hispanic subgroup

Mexican/Mexican Americans 99,227 2.69 [1.91-3.47] 10,008 0.27 [0.03-0.50]

Puerto Ricans 29,801 3.74 [0.71-6.74] —c —c

Cubans/Cuban Americans 15,874 3.03 [1.09-4.97] —c —c

Dominicans 6210 3.13 [�1.34, 7.60] —c —c

Central/South Americans 10,426 1.01 [0.32-1.70]d —c —c

Other Hispanics 9948 2.61 [0.73-4.49] 1417 0.37 [�0.35, 1.09]

Abbreviations: CI, confidence interval.a Estimates of the total number of women were based on weighted data from National Health Interview Survey Cancer Control Modules from the years 2000

and 2005. The American Society of Clinical Oncology and the National Comprehensive Cancer Network define a high risk of breast cancer if the BCRAT 5-

year risk �1.67% and/or BCRAT lifetime risk �20%.bP < .001 (2-sided chi-square test comparing all Hispanics with to non-Hispanic whites).c For this category, there were too few observations to report.dP < .001 (2-sided chi-square test comparing each respective Hispanic subgroup with Mexican/Mexican American women).

TABLE 2. Mean Breast Cancer Risk AssessmentTool 5-Year and Lifetime Absolute Risk Estimatesby Hispanic Subgroupa

Participant Subgroup Total No.BCRAT 5-Year Risk

BCRATLifetime Risk

Non-Hispanic whites 53,600,388 1.24 [1.23-1.26] 8.63 [8.56-8.70]

All Hispanics 6,616,996 0.64 [0.62-0.66]b 5.88 [5.77-5.99]b

Hispanic subgroup

Mexican/Mexican

Americans

3,682,494 0.62 [0.60-0.65] 5.83 [5.70-5.95]

Puerto Ricans 795,878 0.67 [0.60-0.74] 5.82 [5.53-6.10]

Cubans/Cuban

Americans

523,990 0.83 [0.76-0.89]c 5.47 [5.14-5.80]

Dominicans 198,432 0.62 [0.54-0.70] 6.68 [6.17-7.18]c

Central/South

Americans

1,034,701 0.59 [0.55-0.62] 6.23 [5.95-6.51]c

Other Hispanics 381,500 0.70 [0.64-0.75]c 5.71 [5.15-6.27]

Abbreviations: BCRAT, Breast Cancer Risk Assessment Tool; CI, confidence

interval.a Estimates of the total number of women are based on weighted data from

National Health Interview Survey Cancer Control Modules for the years

2000 and 2005. Bivariate linear regression analyses were conducted.bP < .001 (2-sided t test comparing all Hispanics with non-Hispanic

whites).cP < .001 (2-sided t test comparing each respective Hispanic subgroup

with Mexican/Mexican American women).



controlling for all covariates (P < .001). There were noother differences observed in lifetime absolute risk whencomparing Other Hispanic subgroups with Mexican/Mexican American women.

Comparing all Hispanics with non-Hispanic whites,age, education, poverty level, insurance status, and BMIwere all significantly associated with women’s 5-year abso-lute risk of breast cancer (results not shown). In particular,increased age, having public health insurance, and beingoverweight/obese were all associated with significantincreases in the 5-year absolute risk. Similar trends wereobserved for the lifetime absolute risk of breast cancer,although increased age was associated with a significantlylower lifetime absolute risk of breast cancer. In compari-sons between Hispanic subgroups, age, marital status,education, poverty level, insurance status, and years in theUnited States were associated significantly with the 5-yearabsolute risk of breast cancer (results not shown). Specifi-cally, women from the same Hispanic subgroup who hadlived in the United States for less than 5 years had a signif-icantly lower 5-year absolute risk of breast cancer com-pared with women who were born in the United States (P< .05), controlling for all other covariates. This associa-tion was not observed for the lifetime risk of breast cancer.

DISCUSSIONBuilding on the current literature, the current study was abroad assessment of the absolute risk of developing breast

cancer among different subgroups of Hispanic women.Our findings indicate that, among Hispanic women over-all, the 5-year and lifetime absolute risks of developinginvasive breast cancer, based on the BCRAT, were signifi-cantly lower compared with the risks among non-His-panic white women. Among Hispanic subgroups, Cuban/Cuban American women had a greater BCRAT 5-yearabsolute risk of developing invasive breast cancer, whereasDominican women had a greater BCRAT lifetime abso-lute risk of developing invasive breast cancer. Factors thatwere associated with differences in breast cancer riskamong Hispanic subgroups included age, education,health insurance status, usual source of care, poverty level,and length of residence in the United States. Furthermore,the proportion of Hispanic women who may be eligiblefor breast cancer risk-reduction strategies, such as thereceipt of prophylactic tamoxifen and raloxifene, based onASCO and NCCN guidelines, ranges from approxi-mately 1% of Central/South American women to 4% ofPuerto Rican women.

Consistent with previous reports,26 we observed thatHispanic women have a significantly lower 5-year andlifetime absolute risk of developing invasive breast cancerbased on the BCRAT. Furthermore, the magnitude bywhich Hispanic women’s breast cancer risk was lowerthan non-Hispanic white women’s risk remained signifi-cant and relatively constant, even after multivariate adjust-ment for key risk factors. These findings suggest that

TABLE 4. Results From Multivariate Regression Analyses of Breast Cancer Risk Assessment Tool 5-Year andLifetime Absolute Risk of Breast Cancer by Hispanic Subgroup

b Estimate (SE)a

BCRAT 5-Year Risk BCRAT Lifetime Risk

Participant Subgroup Model 1 Model 2 Model 3 Model 4 Model 1 Model 2 Model 3 Model 4

Non-Hispanic whites Ref Ref Ref Ref Ref Ref Ref Ref

All Hispanics �0.41 (0.01)b �0.41 (0.01)b �0.41 (0.01)b �0.42 (0.02)b �2.86 (0.07)b �2.81 (0.07)b �2.79 (0.07)b �2.77 (0.08)b

Mexican/Mexican Americans Ref Ref Ref Ref Ref Ref Ref Ref

Puerto Rican 0.02 (0.03) 0.01 (0.03) 0.00 (0.03) 0.01 (0.03) 0.02 (0.14) �0.00 (0.14) �0.06 (0.14) �0.00 (0.14)

Cuban/Cuban Americans 0.05 (0.02)c 0.05 (0.03)c 0.04 (0.03) 0.05 (0.03)c 0.18 (0.17) 0.16 (0.18) 0.11 (0.18) 0.15 (0.18)

Dominicans 0.02 (0.03) 0.01 (0.03) 0.02 (0.03) 0.03 (0.03) 0.73 (0.21)d 0.75 (0.23)c 0.82 (0.25)d 0.85 (0.26)d

Central/South Americans �0.02 (0.03) �0.01 (0.02) �0.01 (0.02) 0.01 (0.02) 0.04 (0.11) 0.05 (0.12) 0.07 (0.12) 0.12 (0.12)

Other Hispanics �0.00 (0.03) �0.01 (0.03) �0.01 (0.03) �0.01 (0.03) �0.19 (0.21) �0.20 (0.21) �0.23 (0.22) �0.23 (0.22)

Abbreviations: BCRAT, Breast Cancer Risk Assessment Tool; Ref, referent category; SE, standard error.a The b estimates presented are: 1) differences in BCRAT estimates of the absolute risk of developing breast cancer over the next 5 years (BCRAT 5-year risk)

between Hispanic versus non-Hispanic whites and between Hispanics subgroups; and 2) differences in BCRAT estimates of the absolute risk of developing

breast cancer over an individual’s lifetime (BCRAT lifetime risk) between Hispanic versus non-Hispanic whites and between Hispanics subgroups (eg a BCRAT

5-year risk of 1.10% compared with 1.06% is a difference of �0.4 percentage points). The b estimates were obtained by multivariate linear regression analy-

ses. Model 1 was adjusted for age, marital status, education, and federal poverty level; Model 2 was adjusted for Model 1 covariates plus usual source of

care and insurance; Model 3 was adjusted for Model 2 covariates plus body mass index; and Model 4 was adjusted for Model 3 covariates plus US born (US

vs foreign born), years in the United States (US born, �5 years, >5 years).bP < .001 (2-sided chi-square test comparing all Hispanics with non-Hispanic whites).cP < .05 (2-sided chi-square test comparing each respective Hispanic subgroup with Mexican/Mexican American women).dP < .001 (2-sided chi-square test comparing each respective Hispanic subgroup with Mexican/Mexican American women).

Original Article


other factors, either unidentified and/or unmeasured inour analysis, may help explain the differences observed inBCRAT risk estimates between Hispanic women andnon-Hispanic white women.

Evidence regarding the risk of developing breastcancer among Hispanic women has highlighted differen-ces between US-born and foreign-born women.17 Resultsfrom the San Francisco Bay Area Women’s Breast CancerStudy demonstrated that foreign-born Hispanic, post-menopausal women had a significantly lower risk of breastcancer compared with their US-born counterparts. Ourcurrent study expands on this finding by evaluating differ-ences in risk by Hispanic subgroup, and the results indi-cate that, compared with Mexican/Mexican Americanwomen, Cuban/Cuban American women have a signifi-cantly higher 5-year risk of breast cancer, whereas Domi-nicans have a significantly higher lifetime risk of breastcancer. Consequently, although BCRAT risk amongOther Hispanic subgroups did not differ, the increasedrisk among Cuban/Cuban American women and Domin-ican women may reflect other important underlying fac-tors, such as genetic ancestry,27 that account fordifferences in BCRAT estimates of the risk of developinginvasive breast cancer among these Hispanic subgroups.

Our finding of lower breast cancer risk in foreign-born Hispanic women who have <5 years of residence inthe United States further strengthens the importance ofbirthplace, migration, and length of residence in theUnited States as factors associated with breast cancer riskamong Hispanic women.17,28 Therefore, migration-related changes experienced by Hispanic women whomove to the United States, such as those to hormones andlifestyle factors (ie, weight gain or changes in diet), mayhave important ramifications for the risk of developingbreast cancer.

It is noteworthy that our study is among the first, ifnot the only, to provide an estimate of the proportion andnumber of women from different Hispanic subgroupswho may be eligible to receive prophylactic tamoxifen andraloxifene. Both the ASCO and the NCCN recommendthat patients who meet the high-risk threshold of BCRAT5-year risk �1.67% are eligible for, and may consider,counseling about prophylactic tamoxifen or raloxifene toreduce the risk of developing invasive breast cancer in thefuture.29,30 Thus, as indicated by our findings, up to2.7% of Mexican American women (approximately99,000 women) and 3.7% of Puerto Rican women(approximately 30,000 women), among others, may ben-efit from risk-reduction counseling to consider theiroptions for preventing the onset of breast cancer.

In interpreting the results from this study, it is im-portant to acknowledge its strengths and limitations. TheNHIS is a large, population-based study, which allowedus to explore US Hispanic women; however, our studywas limited by small samples of women from certain His-panic subgroups. Nevertheless, these findings build onprevious studies of breast cancer risk among different sub-groups of Hispanic women, adding considerably to thesparse literature documenting the heterogeneity of theHispanic population. A possible limitation of this study isthat the NHIS is a cross-sectional study; therefore, we arenot able to draw any causal inference regarding the rela-tion between breast cancer risk and the risk factors thatwere included in our analysis. Another limitation is theuse of the NCI BCRAT to estimate breast cancer risk inHispanic women, since evidence suggests it may underes-timate risk in this population.31 Despite such underesti-mation, our findings represent a conservative estimate ofbreast cancer risk among Hispanic women and the num-ber of women in each subgroup who may benefit fromrisk-reduction strategies.

In summary, our findings indicate that, based on theBCRAT, Hispanic women have a significantly lowerabsolute risk of developing invasive breast cancer com-pared with non-Hispanic white women; furthermore, wehighlight differences in the BCRAT risk among womenin different Hispanic subgroups. Although country of ori-gin and length of residence were associated significantlywith BCRAT risk estimates in our study sample, it is im-perative to further investigate how Hispanic ancestry andmigration affect women’s risk factors for developingbreast cancer. Finally, we provide national estimates of thenumber of Hispanic women, from six key subgroups, whowould be eligible for counseling to consider risk reductionby prophylactic breast cancer chemoprevention, as recom-mended by the ASCO and the NCCN. Future studies arewarranted that further investigate the impact of breastcancer among Hispanics of different ancestry along withother important breast cancer risk factors, such as historyof cancer in second-degree and higher degree relatives inthis population.

FUNDING SOURCESDr. Banegas conducted this work while he was at the Universityof Washington and Fred Hutchinson Cancer Research Centerand was supported in part by the National Cancer Institute Bio-behavioral Cancer Prevention and Control Training Program(grant R25CA092408) at the University of Washington and bythe National Cancer Institute Center for Hispanic Health Pro-motion Training Program (grant U54CA153502) at the FredHutchinson Cancer Research Center.



CONFLICT OF INTEREST DISCLOSURESThe authors made no disclosures.

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The risk of developing invasive breast cancer in Hispanic women