Mapping cancer mortality-to-incidence ratios to illustrate racial and sex disparities in a high-risk population.
BACKGROUND
Comparisons of incidence and mortality rates are the metrics used most commonly to define cancer-related racial disparities. In the US, and particularly in South Carolina, these largely disfavor African Americans (AAs). Computed from readily available data sources, the mortality-to-incidence rate ratio (MIR) provides a population-based indicator of survival.


METHODS
South Carolina Central Cancer Registry incidence data and Vital Registry death data were used to construct MIRs. ArcGIS 9.2 mapping software was used to map cancer MIRs by sex and race for 8 Health Regions within South Carolina for all cancers combined and for breast, cervical, colorectal, lung, oral, and prostate cancers.


RESULTS
Racial differences in cancer MIRs were observed for both sexes for all cancers combined and for most individual sites. The largest racial differences were observed for female breast, prostate, and oral cancers, and AAs had MIRs nearly twice those of European Americans (EAs).


CONCLUSIONS
Comparing and mapping race- and sex-specific cancer MIRs provides a powerful way to observe the scope of the cancer problem. By using these methods, in the current study, AAs had much higher cancer MIRs compared with EAs for most cancer sites in nearly all regions of South Carolina. Future work must be directed at explaining and addressing the underlying differences in cancer outcomes by region and race. MIR mapping allows for pinpointing areas where future research has the greatest likelihood of identifying the causes of large, persistent, cancer-related disparities. Other regions with access to high-quality data may find it useful to compare MIRs and conduct MIR mapping.
Hébert
James R
JR
South Carolina Statewide Cancer Prevention and Control Program, University of South Carolina, Columbia, South Carolina 29208, USA. jhebert@sc.edu
Daguise
Virginie G
VG
Hurley
Deborah M
DM
Wilkerson
Rebecca C
RC
Mosley
Catishia M
CM
Adams
Swann A
SA
Puett
Robin
R
Burch
James B
JB
Steck
Susan E
SE
Bolick-Aldrich
Susan W
SW
D001741:Black or African American; D005260:Female; D006306:Health Surveys; D054625:Healthcare Disparities; D006801:Humans; D015994:Incidence; D008297:Male; D009369:Neoplasms / Q000453:epidemiology / Q000208:ethnology* / Q000401:mortality; D012042:Registries; D013022:South Carolina / Q000453:epidemiology; D044465:White People