The impact of socioeconomic status on survival after cancer in the United States : findings from the National Program of Cancer Registries Patterns of Care Study.
BACKGROUND
Understanding the ways in which socioeconomic status (SES) affects mortality is important for defining strategies to eliminate the unequal burden of cancer by race and ethnicity in the United States.


METHODS
Disease stage, treatment, and 5-year mortality rates were ascertained by reviewing medical records, and SES was determined by analyzing income and education at the census tract level for 4844 women with breast cancer, 4332 men with prostate cancer, and 4422 men and women with colorectal cancer who were diagnosed in 7 U.S. states in 1997.


RESULTS
Low SES was associated with more advanced disease stage and with less aggressive treatment for all 3 cancers. The hazard ratio (HR) for 5-year all-cause mortality associated with low SES was elevated after a diagnosis of breast cancer when the analysis was adjusted for age (HR, 1.59; 95% confidence interval [CI], 1.35-1.87). Adjustment for mediating factors of race/ethnicity, comorbid conditions, cancer stage, and treatment reduced the association. The age-adjusted mortality risk associated with low SES was elevated after a diagnosis of prostate cancer (HR, 1.33; 95% CI, 1.13-1.57), and multivariate adjustments for mediating factors also reduced that association. There was less association between SES and mortality after a diagnosis of colorectal cancer. For all 3 cancer sites, low SES was a much stronger predictor of mortality among individuals aged <65 years and among individuals from racial/ethnic minority groups.


CONCLUSIONS
The current results indicated that low SES is a risk factor for all-cause mortality after a diagnosis of cancer, largely because of a later stage at diagnosis and less aggressive treatment. These findings support the need to focus on SES as an underlying factor in cancer disparities by race and ethnicity.
Byers
Tim E
TE
Department of Epidemiology, Colorado School of Public Health, Aurora, Colorado 80045, USA. tim.byers@uchsc.edu
Wolf
Holly J
HJ
Bauer
Katrina R
KR
Bolick-Aldrich
Susan
S
Chen
Vivien W
VW
Finch
Jack L
JL
Fulton
John P
JP
Schymura
Maria J
MJ
Shen
Tiefu
T
Van Heest
Scott
S
Yin
Xiang
X
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000208:ethnology / Q000401:mortality*; D011787:Quality of Health Care / Q000706:statistics & numerical data; D012042:Registries; D012111:Residence Characteristics; D012923:Social Class; D016019:Survival Analysis; D017741:Survivors / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology