Race/ethnicity and changing US socioeconomic gradients in breast cancer incidence: California and Massachusetts, 1978-2002 (United States).
OBJECTIVE
We tested the hypothesis that the US socioeconomic gradient in breast cancer incidence is declining, with the decline most pronounced among racial/ethnic groups with the highest incidence rates.


METHODS
We geocoded the invasive incident breast cancer cases for three US population-based cancer registries covering: Los Angeles County, CA (1978-1982, 1988-1992, 1998-2002; n = 68,762 cases), the San Francisco Bay Area, CA (1978-1982, 1988-1992, 1998-2002; n = 37,210 cases) and Massachusetts (1988-1992, 1998-2002; n = 48,111 cases), linked the records to census tract area-based socioeconomic measures, and, for each socioeconomic stratum, computed average annual breast cancer incidence rates for the 5-year period straddling the 1980, 1990, and 2000 census, overall and by race/ethnicity and gender.


RESULTS
Our findings indicate that the socioeconomic gradient in breast cancer incidence is: (a) relatively small (at most 1.2) and stable among US white non-Hispanic and black women; (b) sharper and generally increasing among Hispanic and Asian and Pacific Islander American women; and (c) cannot be meaningfully analyzed without considering effect modification by race/ethnicity and immigration.


CONCLUSIONS
Our results indicate that secular changes in US socioeconomic gradients in breast cancer incidence exist and vary by race/ethnicity.
Krieger
Nancy
N
Department of Society, Human Development and Health, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA, 02115, USA. nkrieger@hsph.harvard.edu
Chen
Jarvis T
JT
Waterman
Pamela D
PD
Rehkopf
David H
DH
Yin
Ruihua
R
Coull
Brent A
BA
D001943:Breast Neoplasms / Q000453:epidemiology* / Q000208:ethnology; D002140:California / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008404:Massachusetts / Q000453:epidemiology; D012959:Socioeconomic Factors