Trends in area-socioeconomic and race-ethnic disparities in breast cancer incidence, stage at diagnosis, screening, mortality, and survival among women ages 50 years and over (1987-2005).
BACKGROUND
Breast cancer is the most commonly diagnosed cancer and the second leading cause of cancer death among women in the United States and varies systematically by race-ethnicity and socioeconomic status. Previous research has often focused on disparities between particular groups, but few studies have summarized disparities across multiple subgroups defined by race-ethnic and socioeconomic position.


METHODS
Data on breast cancer incidence, stage, mortality, and 5-year cause-specific probability of death (100 - survival) were obtained from the Surveillance, Epidemiology, and End Results program and data on mammography screening from the National Health Interview Survey from 1987 to 2005. We used four area-socioeconomic groups based on the percentage of poverty in the county of residence (<10, 10-15, 15-20, +20%) and five race-ethnic groups (White, Black, Asian, American Indian, and Hispanic). We used summary measures of disparity based on both rate differences and rate ratios.


RESULTS
From 1987 to 2004, area-socioeconomic disparities declined by 20% to 30% for incidence, stage at diagnosis, and 5-year cause-specific probability of death, and by roughly 100% for mortality, whether measured on the absolute or relative scale. In contrast, relative area-socioeconomic disparities in mammography use increased by 161%. Absolute race-ethnic disparities declined across all outcomes, with the largest reduction for mammography (56% decline). Relative race-ethnic disparities for mortality and 5-year cause-specific probability of death increased by 24% and 17%, respectively.


CONCLUSIONS
Our analysis suggests progress towards race-ethnic and area-socioeconomic disparity goals for breast cancer, especially when measured on the absolute scale. However, greater progress is needed to address increasing relative socioeconomic disparities in mammography and race-ethnic disparities in mortality and 5-year cause-specific probability of death.
Harper
Sam
S
Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, 1020 Pine Avenue West, Room 34, Montreal, Quebec, Canada H3A 1A2. sam.harper@mcgill.ca
Lynch
John
J
Meersman
Stephen C
SC
Breen
Nancy
N
Davis
William W
WW
Reichman
Marsha C
MC
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000208:ethnology / Q000401:mortality / Q000473:pathology; D005006:Ethnicity; D005260:Female; D054625:Healthcare Disparities; D006801:Humans; D015994:Incidence; D008403:Mass Screening; D008875:Middle Aged; D009367:Neoplasm Staging; D011203:Poverty; D018426:SEER Program; D012959:Socioeconomic Factors; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology