Brain Cancer Mortality in the United States Joint work with: Zixing Fang, UCLA David Gregorio, Univ Connecticut
U.S. Brain Cancer Mortality deathsrate* (95% CI) Children (age <20): 5, ( ) Adults (age 20+): 106,7106.0( ) Adult Women: 48,6504.9( ) Adult Men: 58,0607.2( ) * annual deaths / 100,000
Brain Cancer Known risk factors: High dose ionizing radiation Selected congenital and genetic disorders Explains only a small percent of cases. Potential risk factors: N-nitroso compounds?, phenols?, pesticides?, polycyclic aromatic hydrocarbons?, organic solvents?
Adjustments Age Gender Ethnicity (African-American, White, Other) All subsequent analyses where adjusted for:
Brain Cancer Mortality, Children
Cuzick-Edward’s Test: Children k p-value
Tango’s Excess Events Test: Children p-value
Spatial Scan Statistic, Children
Children: Seven Most Likely Clusters Cluster Obs Exp RR p= 1. Carolinas California Michigan S Carolina Kentucky-Tenn Wisconsin Nebraska
Conclusions: Children Some evidence of global spatial clustering, but rather weak. No statistically significant clusters detected. Any part of the pattern seen on the original map may be due to chance.
How About Adults?
Brain Cancer Mortality, Adults
Cuzick-Edward’s k-NN: All Adults k p-value
Tango’s EET: All Adults p-value
Spatial Scan Statistic: Adults
Brain Cancer Mortality, Adults
Cuzick-Edward’s: Women k p-value
Tango’s EET: Women p-value
Spatial Scan Statistic, Women
Women: Most Likely Clusters Cluster Obs Exp RR p= 1. Arkansas et al Carolinas Oklahoma et al Minnesota et al N.J. / N.Y S Texas New Mexico et al
Cuzick-Edward’s: Men k p-value
Tango’s EET: Men p-value
Spatial Scan Statistic: Men
Men: Most Likely Clusters Cluster Obs Exp RR p= 1. Kentucky et al Carolinas Arkansas et al Washington et al Michigan N.J. / N.Y S Texas New Mexico et al Upstate N.Y. et al
Conclusions: Adults Strong evidence of global spatial clustering. It is possible to pinpoint specific areas with higher and lower rates that are statistically significant, and unlikely to be due to chance. The exact borders of detected clusters are uncertain. Similar patterns for men and women.
Conclusion: General Tests for spatial randomness are very useful additions to cancer maps, in order to determine if the observed patterns are likely due to chance or not. Different tests provide complementary information.