Mapping and Cancer Disparities

Robin Taylor Wilson, PhDAssistant Professor

Epidemiology DivisionDepartment of Public Health Sciences

Penn State College of Medicine

Overview

Colon Cancer in Pennsylvania

Exploratory Spatial Data Analysis (ESDA) Software Development

Why use spatial data analysis?

Help prioritize cancer control and identify areas of success e.g. left- and right-sided colon cancer screening

Help to understand access to screening and treatment in relation to stage at diagnosis

Classify environmental exposures not readily assessed by questionnaire or biomarkers e.g. organophosphate pesticides e.g. UVB index

Provide etiologic clues to disease e.g. neighborhood context and physical activity

May prevent a major cancer cluster investigation

Spatial Analysis of Left- and Right-Sided Colon Cancer in Pennsylvania Rationale:

The incidence of colon cancer in Pennsylvania is higher than the US all-races rate

Understanding left-sided spatial clustering may help focus cancer screening efforts in the state

Purpose: 1. Determine whether geographic clustering of

colon cancer incidence occurs and whether cluster patterns differ by stage and site (left- versus right-sided)

2. Identify county-level characteristics associated with incidence

Methods: Colon Cancer in PA Cases diagnosed between 1994-2002 were identified

through the Pennsylvania Cancer Registry

Principal components analysis was used to create a county-level SES index based on 7 variables from the 2000 Census

County-level colon cancer screening and obesity prevalence were derived from the Behavioral Risk Factor Surveillance System

SaTScan was used to determine geographic clustering by county, adjusted for confounding variables

Poisson regression estimated incidence rate ratios (IRR) and 95% confidence intervals (CI) according to the county-distribution of age, sex, race, SES index, obesity, screening, and rural residence as defined by the Beale rural-urban continuum

Colon Cancer: Case Characteristics

Right-Side Left-Side Factor Count Percent Count Percent P-value

Individual-Level Variables Gender Male 13,809 43.5 12,001 52.5 <0.001 Female 17,959 56.5 10,848 47.5 Race White 29,148 91.8 20,844 91.2 <0.001 Black 2,320 7.3 1,698 7.4 Other 300 0.9 307 1.3 Age (years) 00-39 381 1.2 285 1.2 <0.001 40-49 1,086 3.4 1,043 4.6 50-64 4,967 15.6 4,838 21.2 65-74 9,065 28.5 7,429 32.5 75+ 16,269 51.2 9,254 40.5

Components of SES Index: Principal Component 1: 72% of variance

Original Variable Mean (Std Dev.) Min. Max. Loading Correlation

(p-value) Proportion with at least high school education

0.81 (0.04) 0.71 0.89 0.29 0.66

(<0.0001)

Median contract rent ($) 464 (100) 337 757 0.41 0.92

(<0.0001)

Median house value ($) 88479 (26141) 53500 182500 0.43 0.96

(<0.0001) Median household income ($)

37177 (7475) 27451 65295 0.43 0.97

(<0.0001) Proportion of county population older than 16 years in the workforce without a job

0.06 (0.02) 0.03 0.11 -0.27 -0.60

(<0.0001)

Proportion of the county population with a blue-collar job

0.46 (0.08) 0.26 0.60 -0.36 -0.80

(<0.0001)

Proportion of the county population below 200% of the federal poverty level

0.30 (0.07) 0.13 0.43 -0.41 -0.92

(<0.0001)

Right-side Left-side

Factor RR 95% CI Trend

p-value RR 95% CI Trend

p-value

Gender Male 1.14 1.10, 1.18 n/a 1.56 1.51, 1.62 n/a Female ref ref Race Black 1.07 0.99, 1.15 n/a 1.04 0.97, 1.12 n/a Other 1.19 0.99, 1.42 1.50 1.29, 1.75 White ref ref

SES Index (quintile) Lowest 1.06 0.99, 1.14 0.12 1.11 1.03, 1.19 0.003 Low 1.04 0.96, 1.13 1.10 1.01, 1.20 Middle 1.02 0.95, 1.09 1.10 1.02, 1.18 High 1.03 0.97, 1.09 1.05 0.99, 1.12

Highest ref ref FOBT Screening (%) 17.0-26.0 1.00 0.94, 1.06 0.87 1.08 1.02, 1.15 0.007 26.6-31.1 1.03 0.98, 1.08 1.10 1.05, 1.16 31.5-40.8 ref ref Sigmoidoscopy/Colonoscopy Screening (%) 38.8-46.7 0.93 0.88, 0.99 0.04 0.95 0.89, 1.01 0.07 47.3-48.1 0.99 0.94, 1.05 0.96 0.90, 1.01 48.9-63.7 ref ref Obesity (%) 16.7-26.3 0.97 0.91, 1.04 0.27 0.96 0.90, 1.03 0.29 26.7-27.7 0.99 0.93, 1.06 0.97 0.91, 1.04 28.4-32.8 ref ref

Colon Cancer Incidence: Gender, Race and SES Results

SatScan: Spatial Cluster Results

GenderRaceAgeSES

GenderRaceAge

GenderRaceAgeScreening

GenderRaceAgeObesity

Right-sided Left-sided

Gender,Race,Age,SES

Gender,Race,Age,Screening

Summary: Colon Cancer in PA

Lower SES was associated with higher left-sided colon cancer incidence (IRR=1.11, 95% CI: 1.03-1.19, p-trend=0.003), adjusting for age, sex, race, screening and obesity.

Clustering of late stage cancer persisted in two metro regions, including a three-county area in the north east (Beale=2) and two southeastern counties (Beale=1).

Adjustment for SES revealed a cluster of late stage cancer incidence in rural non-metro counties in the western portion of the state.

Conclusion: Colon Cancer in PA

Geographic clustering of left-sided and late stage colon cancer occurs.

The association between left-sided colon cancer and low SES requires replication.

Exploratory Spatial Data Analysis

Incidence Mapping SatScan O/E Local Moran’s I Star Plot overlay Parallel Coordinate Plots

GeoViz Toolkit

ESDA Example: Prostate Cancer Health Disparities

Multiple State Partners New York New Jersey Iowa South Carolina Kentucky Georgia Pennsylvania

County-level and Census-Tract analyses

Prostate Cancer Incidence, White Population, 2000

Acknowledgements Penn State Department of Public Health Sciences

Eugene Lengerich Erik Lehman Yihai Liu

Penn State Department of Geography Frank Hardisty Mark Gahegan Dan Addyson

State Partners Gene Weinberg, Pennsylvania Department of Health Tim Aldrich and Shannon Shropshire, East Tennessee State University Jay Christian, University of Kentucky Michele West and Gerard Rushton, University of Iowa Frank Boscoe, School of Public Health, SUNY Colleen McLaughlin, NY State Department of Health Stanley Weiss, University of Medicine and Dentistry of New Jersey

Thank you

Figure: Map of counties in Pennsylvania.

Adjusted for

GenderRaceAgeSES

GenderRaceAge

GenderRaceAgeScreening

GenderRaceAgeObesity

Panel

1

2

3

4

SatScan: High and Low Clustering

Right Sided Left Sided

Correlation between Model Covariates: SES Index, Screening prevalence and Obesity

SES Blood stool

Sigmoid-oscopy Obesity

SES1

Blood stool 0.230.0578

1

Sigmoidoscopy 0.68<.0001

0.340.0047

1

Obesity -0.310.0096

0.340.0051

-0.350.0037

1

Anatomy of colon and rectum

Right Colon

Left Colon

SatScan: Observed to Expected Results

Right-sided Colon Cancer Left-sided Colon Cancer

Cluster No. of

Counties Obs. No.

Exp. No.

O/E Ratio

p- value

No. of Counties

Obs. No.

Exp. No.

O/E Ratio

p- value

Adjusted for county population structure of gender, race and age

1 2 5527 5196.83 1.06 0.001 2 4074 3722.01 1.09 0.001 2 20 4970 4707.16 1.06 0.012 10 2435 2220.25 1.10 0.001

Adjusted for gender, race, age and SES 1 2 5527 5151.91 1.07 0.001 10 2435 2128.22 1.14 0.001 2 21 5009 4737.15 1.06 0.002 2 4074 3718.52 1.10 0.001

Adjusted for gender, race, age and colon cancer screening prevalence 1 2 5527 5169.38 1.07 0.001 2 4074 3619.83 1.13 0.001 2 20 4970 4683.77 1.06 0.002 10 2435 2189.61 1.11 0.001

Adjusted for gender, race, age and obesity prevalence 1 13 3988 3322.82 1.20 0.001 12 2728 2204.67 1.24 0.001 2 20 9767 9030.30 1.08 0.001 19 6988 6326.78 1.10 0.001 3 1 1156 1030.62 1.12 0.015

Obesity

Gender,Race,Age