Demographic and geographic variations in Breast Cancer

mortality among US Hispanics

Maria C. Mejia de Grubb, MD, MPH; Barbara Kilbourne, PhD; Courtney Kihlberg, MD, MSPH; and Robert Levine, MD.

Department of Family and Community MedicineMeharry Medical College

Nashville, TN

October 30, 2012

Presenter Disclosures The following personal financial relationships

with commercial interests relevant to this presentation existed during the past 12 months:

“No relationships to disclose”

Background Breast cancer is the leading cause of

cancer death among Hispanic women. Hispanic women have a 20 % greater risk

of dying from breast cancer than non-Hispanic whites once a diagnosis is made even though incidence and mortality are lower.

Several factors might contribute to variations of breast cancer mortality by place.

Objective

Describe demographic and geographic variations in Hispanic mortality from malignant neoplasm of the breast among US women ages 35-64 and 65-85+ years.

Methods Age-adjusted (Year 2000 standard) mortality rates

and 95% confidence intervals were obtained from the Compressed Mortality File as presented on the public US Centers for Disease Control and Prevention WONDER (Wide-ranging Online Data for Epidemiologic Research) internet website.

ICD-10 code C50 (Malignant neoplasm of the breast)

All analyses were performed using SAS, v9.23

OLS regression models with dependent variable= age adjusted mortality rates (35-64 and 65-85+ years), and independent variables % Hispanics ≥25 years = annual income below poverty, not high school graduates, and renters.

Results

Table 1. Hispanic and Non-Hispanic, Age-adjusted Female Breast Cancer Mortality According to Race (Ages 35-85+ years). 1999-2009. USA

Age Group Hispanic

Age-Adjusted

Rate

Non-Hispanic

Age-Adjusted

Rate

Hispanic: Non-

Hispanic MRR*

35-85+Years

AI/AN 4.7(3.3 – 6.4) AI/AN 29.6

(28.1 – 31.1) 0.16

AA 13.3(11.9 – 14.8) AA 64.3

(63.8 – 64.8) 0.21

API 21.4(17.4 – 25.4) API 23.5

(23 – 24) 0.91

W 30.7(30.3 – 31.2) W 47.5

(47.3 – 47.6) 0.65

Key: AA = Black or African American; AI/AN = American Indian or Alaska Native; API = Asian or Pacific Islander; W = White. *MMR= Hispanic: Non-Hispanic Mortality Rate Ratio.

Age Group HispanicAge-

AdjustedRate

Non-Hispanic

Age-Adjusted

Rate

Hispanic: Non-Hispanic

MMR*

35-64 Years

AI/AN 3.2(2.1 – 4.5)

AI/AN 17.6(16.5 – 18.8) 0.18

AA 7.9(6.8 – 9)

AA 43.6(16.5 – 44.1) 0.18

API 11.4(8.9 – 14.4)

API 17(16.6 – 17.5) 0.67

W 19.7(19.3 – 20.1)

W 26.6(26.5 – 26.8) 0.74

65-85 +Years

AI/AN 9.4(5.1 – 15.7)

AI/AN 66.2(61.3 – 71.1) 0.14

AA 29.9(25.1 – 34.8)

AA 127.1(125.6 – 128.6) 0.26

API 51.6(38.7 – 67.5)

API 43.3(41.7 – 44.9) 1.19

W 64.3(62.9 – 65.7)

W 110.9(110.5 – 111.4) 0.58

Table 2. Hispanic and Non-Hispanic, Age-adjusted Female Breast Cancer Mortality According to Race and Age. 1999-2009. USA

Table 3. Hispanic and Non-Hispanic, Age-adjusted Female Breast Cancer Mortality (Age 35-64 years) According to Race and Census Region. 1999-2009. USA

Age groupCensus Region

HispanicAge

Adjusted Rate

Non-Hispanic

Age Adjusted

Rate

Hispanic: Non-

Hispanic MMR*

35-64 years

NortheastAA 7.5 AA 41.2 0.18

W 21 W 27 0.78

MidwestAA 8.3 AA 44.1 0.19

W 15.8 W 26.2 0.60

South

API 9.3 API 13.4 0.69

AA 11.7 AA 44.4 0.26

W 19.9 W 26.8 0.74

West

AI/AN 4.6 AI/AN 18 0.26

API 13.9 API 20.3 0.68

AA 3.5 AA 43.3 0.08

W 20.2 W 26.5 0.76

Key: AA=Black or African American; AI/AN= American Indian or Alaskan Native; API= Asian or Pacific Islander; W=White. Census Region 1: Northeast; Census Region 2: Midwest; Census Region 3: South; Census Region 4: West. Absence of racial groups reflects lack of sufficient data to meet standards of confidentiality.

Table 4. Hispanic and Non-Hispanic, Age-adjusted Female Breast Cancer Mortality (Age 65-85+ years) According to Race and Census Region. 1999-2009. USA

Age groupCensus Region

HispanicAge

Adjusted Rate

Non-Hispanic

Age Adjusted

Rate

Hispanic: Non-

Hispanic MMR*

65-85+ years

NortheastAA 27.6 AA 124.9 0.22

W 67.8 W 118.8 0.57

MidwestAA 43 AA 138.7 0.31

W 48.6 W 112.8 0.43

SouthAA 36.7 AA 125.5 0.29

W 66.9 W 103 0.65

West

API 71.7 API 48.7 1.47

AA 23.4 AA 124.5 0.19

W 63.9 W 113.9 0.56

Key: AA=Black or African American; AI/AN= American Indian or Alaska Native; API= Asian or Pacific Islander; W=White.

Census Region 1: Northeast; Census Region 2: Midwest; Census Region 3: South; Census Region 4: West. Absence of racial groups reflects lack of sufficient data to meet standards of confidentiality.

Fig.1. Breast Cancer Mortality (Ages 35-64 Years) among Hispanic White Females According to State and Percent Hispanic Population. 1999-2009. USA.

0 5 10 15 20 25 30 35 40 450

5

10

15

20

25

30

NM

CA

TXAZ

FL

NV

NY

NJCO

ILHI

CT

UTRI

ID

WAMD

MA

KS

OR

VA

GA

OK

NE

NC

LA

AK

PA

IN

MI

WI

SC

IA

MN

MOTN

OH

AL

KY

f(x) = 0.273486542567933 x + 13.7492397369293R² = 0.447022936127777

Percent Hispanic Population

Ag

e –A

dju

sted

Bre

ast

Can

cer

Dea

ths

for

100,

000

Po

pu

lati

on

0 5 10 15 20 25 30 350

10

20

30

40

50

60

70

80

90

AZ

CACO

CT

FL

GA

HI

IL

IN

IA

KS

KY

LA

MD

MA

MI

MNMO

NE

NV

NJ

NM

NY

OH

OK

OR

PA

SC

TX

UT

VA

WA

WI

WYf(x) = 1.08402339779356 x + 49.6140261823455R² = 0.219852780156283

Fig.2. Breast Cancer Mortality (Ages 65-85+) among Hispanic White Females According to State and Percent Hispanic Population. 1999-2009. USA

Ag

e –A

dju

sted

Bre

ast

Can

cer

Dea

ths

for

100,

000

Po

pu

lati

on

Percent Hispanic Population

Table 5. Ordinary Least Squares Regression (OLS) predicting Hispanic White Breast Cancer Mortality in 106 US counties. 1999-2009

Hispanic White 35-64 y/o

Variable Parameter Estimate p value

Poverty % 34.71 <0.0001Education % -9.88 0.029Renters % -8.98 0.0006

Hispanic White 65-85+ y/o

Variable Parameter Estimate p value

Poverty % 49.6 0.1054Education % -69.54 0.0032Renters % -20.8 0.1003

Poverty %= percentage of Hispanics living in poverty,Education %= percentage of Hispanics with less than a high school education Renters %= percentage of Hispanics that are renters.

Table 6. Correlations Between Breast Cancer Mortality Rates And Percentage Of Population Residing In Places Along The Urban To Rural Continuum By State

Age Group

Large Metropolitan

Areas

Large Metropolitan

Fringe

Medium Metropolitan

Small Metropolitan

MicropolitanNon-core

35-64 y/oN=39

0.346*p=0.031

-0.094p=0.567

-0.101p=0.657

-0.046p=0.780

-0.200p=0.223

-0.308*p=0.056

65 + y/oN=34

0.168p=0.342

-0.447**p=0.008

0.041p=0.818

0.173p=0.327

0.133p=0.452

0.208p=0.109

Strengths and Limitations

Strengths: Mortality data has been validated for breast cancer

and Hispanic ethnic classifications on death certificates.

The use of state level data allows to detect patterns of geographical variations.

Limitations: Social and structural factors are suitable for

hypothesis generation but not for hypothesis testing.

Small power for detection of ethnic variations within Hispanic population.

Conclusions

The data showed significant geographic and racial variations among Hispanic populations.

Analytic epidemiologic studies are needed to ascertain the underlying reasons, with special reference to particularly strong protective effects among AI/AN and AA Hispanics relative to non-Hispanic AI/AN and AA groups.

The observation of relatively high rates among elderly API residents in the western region needs further exploration.

Consideration of these factors would contribute to public health planning efforts.

Acknowledgements

This research was supported grant number 5 P20 MD 000516 from the National Institute of Minority Health and Health Disparities.

Contact: mmejiadegrubb@mmc.edu