Aldo Aviña Environmental and Occupational Health Spatio-Temporal Analysis of Lymphoid Leukemia Mortality in Children aged 0-4 in Texas Counties, 1999-2007 Aldo Aviña Environmental and Occupational Health

Leukemia Affects blood and bone marrow Four most common types Acute Myeloid Leukemia (AML) Acute Lymphoblastic Leukemia (ALL) Chronic Myeloid Leukemia (CML) Chronic Lymphocytic Leukemia (CLL)

Leukemia Risk factors Environmental exposures Cancer treatment Smoking Genetic abnormalities Family history

Leukemia Most common cancer in children ALL comprises 25% of malignancies that occur in people <20 years Survivability has increased substantially over last several decades 5-year survival, >80% by year 2000 (Smith et al, 1999; Ries et al, 2002)

Leukemia 5-year survival, ALL, 1990-1999 84% White children 75% Black children 72% Hispanic children (Kadan-Lottick et al, 2003)

Leukemia 5-year survival, ALL, 1990-1999 69% overall 34% <1 year old 76% 1-9 years old 52% 10-19 years (Kadan-Lottick et al, 2003)

Research Goal Exploratory research Identify racial disparities in Leukemia mortality across space (Texas) Explore how Leukemia mortality is heterogeneous in time and space (Texas)

Data VitalWeb Standard (http://www.ehdp.com/vitalweb/use1.htm) Texas County Level ICD-10 Underlying Cause of Death Lymphoid Leukemia ICD C91; Ages 0-4, by race. TIGER/Line Shapefiles (http://www.census.gov/geo/maps-data/data/tiger.html) Population by county

Methods Spatial Scan Statistics Compares observed/expected SaTScan (www.satscan.org) Retrospective space-time analysis Poisson distribution Data stratified by race Compares observed/expected Inside and outside cluster region (Jung, Kulldorf, & Richard, 2003; Kulldorf et al, 1998)

Methods Map visualization Esri’s ArcGIS

Most Likely Cluster Model Results for cluster Race Observed Expected Obs/Exp Relative Risk White 119 184 0.65 0.63 Black 8 24 0.34 0.32 Hispanic 128 47 2.70 3.11

Discussion Why is RR of Hispanics 3.11? Count data – Greatest population of Hispanics in Texas Requires further investigation, different model Explore environmental factors Mortality rate within cluster for Whites comparatively low Geography of demographics?

Conclusion Geography and temporality of Leukemia by race Heterogeneous Emphasizes role of geography for targeted prevention and control Questions about place vulnerability Industrial processes, ionizing radiation exposure Targeted studies: What environmental factors associated

Literature Cited Jung I, Kulldorff M, Richard OJ, 2010. A spatial scan statistic for multinomial data. Statistics in Medicine, epub (http://www.satscan.org/papers/jung-M2008.pdf). Kadan-Lottick, NS, Ness, KK, Bhatia, S, Gurney, JG, 2003. Survival Variability by Race and Ethnicity in Childhood Acute Lymphoblastic Leukemia. Journal of the American Medical Association, 290(15), 2008-2014. Kulldorff M, Athas W, Feuer E, Miller B, Key C, 1998. Evaluating cluster alarms: A space-time scan statistic and brain cancer in Los Alamos. American Journal of Public Health, 88, 1377-1380. Ries LAG, Eisner MP, Kosary CL. et al. SEER Cancer Statistics Review, 1973-1999. Bethesda, Md: National Cancer Institute; 2002. Available at:http://seer.cancer.gov/. Smith MA, Ries LAG, Gurney JG, Ross JA. Leukemia. In: Ries LAG, Smith MA, Gurney JG, et al, eds. Cancer Incidence and Survival Among Children and Adolescents: United States SEER Program 1975-1995, National Cancer Institute, SEER Program. Bethesda, Md: National Institutes of Health; 1999. NIH Pub No. 99-4649. Available at: http://www-seer.ims.nci.nih.gov.