Patterns of breast cancer presentation in the United States: does geography matter?

Distribution of breast cancer varies widely throughout the United States. The factors that influence this geographic variability have not been completely defined. In addition, though a number of studies look at regional and state-to-state variability, few studies have examined this issue with regard to the nation as a whole. State-specific breast cancer data were available from the American College of Surgeons National Cancer Data Base in a series of Benchmark Reports. These data were reviewed and stratified with regard to: age at the time of presentation, race, and stage at the time of presentation. The data were further collected into regional cohorts that corresponded to the United States Census Bureau regions. Statistical analyses were then performed to identify any linked or related variables. A total of 811,652 patients with breast cancer were reported. There was a statistically significant relationship between stage at the time of presentation and census region. The greatest percentage of early-stage disease was recorded in the Northeast and the lowest in the South. There was no significant association between age at presentation and geographic region, but there was a significant relationship between race and stage. The nonwhite subgroup had a greater percentage of patients presenting with advanced-stage disease. Finally, regions with a larger percentage of nonurban population had a higher percentage of later-stage disease at presentation. A relationship exists between the pattern of breast cancer presentation and geographical location within the United States. The Northeast--with the highest percentage of urban areas and white population--reported the highest percentage of early-stage breast cancer at presentation, suggesting a link between these variables. Conversely, the South--with more rural and nonwhite population--had the highest percentage of later-stage disease. The causal relationships are not clear-cut, however, and the relationship between geography and breast cancer presentation is likely multifactorial. Further analysis is indicated to uncover any link between geographic variability and overall breast cancer treatment and survival.