Intrastate Variations in Rural Cancer Risk and Incidence: An Illinois Case Study.

CONTEXT: Although rural-urban cancer disparities have been explored with some depth, disparities within seemingly homogeneous rural areas have received limited attention. However, exploration of intrarural cancer incidence may have important public health implications for risk assessment, cancer control, and resource allocation. OBJECTIVE: The objective of this study was to explore intrastate rural cancer risk and incidence differences within Illinois. DESIGN: Illinois's 83 rural counties were categorized into northern, central, and southern regions (IL-N, IL-C, and IL-S, respectively). Chi-square test for independence and analysis of variance calculations were performed to assess regional differences in demographic characteristics, socioeconomic deprivation, smoking history, obesity, cancer-screening adherence, and density of general practitioners. Age-adjusted incidence rates were calculated for 5 cancer categories: all cancers combined, lung, colorectal, breast (female), and prostate cancers. Unadjusted and adjusted incidence rate ratios (IRRs) were calculated to evaluate regional differences in rates for each cancer category. RESULTS: Socioeconomic deprivation varied by region: 4.5%, 6.9%, and 40.6% of IL-N, IL-C, and IL-S counties, respectively (P < .001). Smoking history also significantly differed by region. Mean former/current smoking prevalence in IL-N, IL-C, and IL-S counties was 46.4%, 48.2%, and 51.4%, respectively (P = .006). In unadjusted analysis, IL-C (IRR = 1.12; 95% confidence interval [CI], 1.02-1.23) and IL-S (IRR = 1.24; 95% CI, 1.13-1.35) had increased lung cancer incidence compared with IL-N. Elevated risk remained in IL-S after adjusting for relevant factors such as smoking and socioeconomic deprivation (IRR = 1.14; 95% CI, 1.04-1.26). CONCLUSIONS: Socioeconomic deprivation, health behaviors, and lung cancer incidence varied across rural regions. Our findings underscore the importance of identifying cancer risk heterogeneity, even within a state, to effectively target risk factor reduction and cancer control interventions.

Impact of county rurality and urologist density on urological cancer mortality in illinois.

PURPOSE: The urology work force is contracting at a time when service demand is increasing due to demographic changes, especially in rural areas. We investigated the impact of rural status and urologist density on kidney and renal pelvis, bladder and prostate cancer mortality at the county level in Illinois. MATERIALS AND METHODS: We stratified the 102 Illinois counties by 2003 RUCCs as urban (36, RUCCs 1 to 3) and rural (66, RUCCs 4 to 9). Area Health Resource Files were used for county demographic data and urologist density. County level age adjusted mortality rates from 1990 to 2010 were derived from National Center for Health Statistics data using SEER*Stat. We examined the associations of urological cancer mortality rates with rural status and urologist density. RESULTS: Average urologist density significantly differed between rural and urban counties (1.9 vs 3.4/100,000 population, p < 0.01). The kidney and renal pelvis cancer mortality rate in rural counties was higher than in urban counties while that of prostate cancer was lower (4.9 vs 4.3 and 28.7 vs 32.2/100,000 population, respectively, each p < 0.01). Urologist density correlated with the mortality rate of kidney and renal pelvis cancer (Pearson coefficient -0.33, p < 0.01) but not with the bladder or prostate cancer mortality rate. Multiple regression analysis revealed that rurality and lower urologist density (p = 0.01 and < 0.05) were significantly associated with higher kidney and renal pelvis cancer mortality. CONCLUSIONS: Rural residence and low urologist density were associated with increased kidney and renal pelvis cancer mortality on the county level in Illinois. Further expansion and testing of evidence-based telemedicine is warranted because remote technical consultation is now technologically feasible, effective, inexpensive and satisfactory to patients.

Manuscript title: Geospatial analysis of Cancer risk and residential proximity to coal mines in Illinois.

BACKGROUND: Studies have indicated a population-level association between coal mining and cancer incidence and mortality, but few studies specifically examined residential proximity to this exposure using spatial analysis. We utilized a Geographic Information Systems (GIS) approach to perform spatial and statistical analyses to test two coal mining exposure variables and their associations with cancer incidence and mortality in Illinois--the fourth highest coal producing state in the United States. METHODS: Data included age-adjusted county-level cancer incidence and mortality for five cancers: all malignant, lung, colorectal, breast (female) and prostate. Coal mining exposure was defined by two variables: coal production group and distance-weighted exposure. Spatial analyses were performed to identify spatial clustering. Correlation and stepwise regression analyses were performed to explore the relationship between cancer incidence and mortality and coal mining exposures. Covariates considered in regression analyses included socioeconomic deprivation, former/current smoking prevalence, race, and rurality. RESULTS: Global spatial autocorrelation indicated significant spatial clustering of incidence, mortality and aggregated coal production. Distance-weighted exposure was significantly correlated with coal production group, age-adjusted all cancer incidence and age-adjusted all cancer mortality. Regression analyses indicated an association between recent coal production and colorectal cancer incidence (p=0.009) and mortality (p=0.035) and prostate cancer mortality (p=0.047). Distance weighted exposure was associated with lung cancer incidence (p=0.004) and mortality (p<0.001), and all cancer mortality (p<0.001). CONCLUSION: Coal production, incidence and mortality are spatially clustered in Illinois. Exposures to coal mining were associated with elevated risk of multiple cancers, most notably lung and colorectal. The environmental impact of the mining industry is substantial, and exposure of individuals residing near coal mines to known carcinogens is plausible. Future studies are needed to further elucidate the population exposure dynamics of coal mining, and should be explored using individual-level exposures and cancer outcomes.

Kidney Cancer in Rural Illinois: Lower Incidence Yet Higher Mortality Rates.

OBJECTIVE: To determine if rural status was associated with kidney and renal pelvis cancer (KCa) incidence and mortality in Illinois while controlling for known KCa risk factors and access to care variables. MATERIALS AND METHODS: Age-adjusted KCa incidence rates from 1991 to 2010 were calculated from Illinois State Cancer Registry data. Age-adjusted KCa mortality rates were obtained from health statistics embedded within SEER*Stat. Rural Urban Continuum Codes designated Illinois' 102 counties as urban, rural adjacent to, and rural non-adjacent to a metropolitan area. County-level demographics and physician density were obtained from the Area Health Resource File. Behavioral Risk Factor Surveillance System data were used for smoking, obesity, and hypertension prevalence. Analysis of variance, correlation, and regression analyses were used. RESULTS: The incidence of KCa was found to be higher among urban compared to rural counties after controlling for known risk factors (P < .01). A larger proportion of cases were diagnosed at a localized stage in urban counties (<0.01). Mortality rates were significantly higher in rural counties (P = .02). The final regression model found rural status, higher incidence rate, fewer with localized stage at diagnosis, and lower urologist density to be variables significantly associated with higher KCa mortality. CONCLUSION: KCa incidence was higher in urban counties whereas mortality was higher in rural counties. The higher number of KCa cases diagnosed at a localized stage in urban counties and lower urologist density in rural counties suggest that poorer access to care may contribute to higher KCa mortality in rural Illinois. Telemedicine may be an opportunity to improve this disparity.

Does where you live play an important role in cancer incidence in the U.S.?

Some studies have shown disproportionate cancer incidence burden in rural areas which may be attributable partly due to the use of 'rural' as a generic term implying homogeneity of risk/protective factors across wide geographic spans. Counties in SEER 18 registries (years 2001-2011) were classified by their Rural-Urban Continuum Code (RUCC) and aggregated into urban, adjacent rural, and non-adjacent rural and were also aggregated into 3 regions: North, South, and West. Two-way ANCOVA was performed with region and RUCC as factors with adjustment for rates of common risk factors obtained from the County Health Rankings (2013). RUCC has a significant effect on incidence rate in urban areas on breast (P =0.001) and prostate (P =0.009). Colorectal significantly varies by region (P<0.0001), and the effect of rurality significantly varies across regions with North highest (P=0.0005). Lung rates significantly vary across both region and RUCC (P<0.0001 and P=0.0001, respectively). The analysis shows that risk-adjusted cancer incidence varies significantly across regions. However, we also found that rural cancer incidence significantly varied across otherwise-similar rural areas implying that 'rural' is not a homogeneous classification.