Spatial Bayesian surveillance for small area case event data.

There has been little development of surveillance procedures for epidemiological data with fine spatial resolution such as case events at residential address locations. This is often due to difficulties of access when confidentiality of medical records is an issue. However, when such data are available, it is important to be able to affect an appropriate analysis strategy. We propose a model for point events in the context of prospective surveillance based on conditional logistic modeling. A weighted conditional autoregressive model is developed for irregular lattices to account for distance effects, and a Dirichlet tessellation is adopted to define the neighborhood structure. Localized clustering diagnostics are compared including the proposed local Kullback-Leibler information criterion. A simulation study is conducted to examine the surveillance and detection methods, and a data example is provided of non-Hodgkin's lymphoma data in South Carolina.

Groundwater uranium and cancer incidence in South Carolina.

OBJECTIVE: This ecologic study tested the hypothesis that census tracts with elevated groundwater uranium and more frequent groundwater use have increased cancer incidence. METHODS: Data sources included: incident total, leukemia, prostate, breast, colorectal, lung, kidney, and bladder cancers (1996-2005, SC Central Cancer Registry); demographic and groundwater use (1990 US Census); and groundwater uranium concentrations (n = 4,600, from existing federal and state databases). Kriging was used to predict average uranium concentrations within tracts. The relationship between uranium and standardized cancer incidence ratios was modeled among tracts with substantial groundwater use via linear or semiparametric regression, with and without stratification by the proportion of African Americans in each area. RESULTS: A total of 134,685 cancer cases were evaluated. Tracts with ≥50% groundwater use and uranium concentrations in the upper quartile had increased risks for colorectal, breast, kidney, prostate, and total cancer compared to referent tracts. Some of these relationships were more likely to be observed among tracts populated primarily by African Americans. CONCLUSION: SC regions with elevated groundwater uranium and more groundwater use may have an increased incidence of certain cancers, although additional research is needed since the design precluded adjustment for race or other predictive factors at the individual level.

Mapping cancer mortality-to-incidence ratios to illustrate racial and sex disparities in a high-risk population.

BACKGROUND: Comparisons of incidence and mortality rates are the metrics used most commonly to define cancer-related racial disparities. In the US, and particularly in South Carolina, these largely disfavor African Americans (AAs). Computed from readily available data sources, the mortality-to-incidence rate ratio (MIR) provides a population-based indicator of survival. METHODS: South Carolina Central Cancer Registry incidence data and Vital Registry death data were used to construct MIRs. ArcGIS 9.2 mapping software was used to map cancer MIRs by sex and race for 8 Health Regions within South Carolina for all cancers combined and for breast, cervical, colorectal, lung, oral, and prostate cancers. RESULTS: Racial differences in cancer MIRs were observed for both sexes for all cancers combined and for most individual sites. The largest racial differences were observed for female breast, prostate, and oral cancers, and AAs had MIRs nearly twice those of European Americans (EAs). CONCLUSIONS: Comparing and mapping race- and sex-specific cancer MIRs provides a powerful way to observe the scope of the cancer problem. By using these methods, in the current study, AAs had much higher cancer MIRs compared with EAs for most cancer sites in nearly all regions of South Carolina. Future work must be directed at explaining and addressing the underlying differences in cancer outcomes by region and race. MIR mapping allows for pinpointing areas where future research has the greatest likelihood of identifying the causes of large, persistent, cancer-related disparities. Other regions with access to high-quality data may find it useful to compare MIRs and conduct MIR mapping.

Racial disparities in cervical cancer mortality in an African American and European American cohort in South Carolina.

South Carolina (SC) has some of the largest health disparities in the nation, in particular cancer mortality rates that disfavor African Americans (AA) in comparison to European Americans (EA) with 37% higher incidence and 61% higher mortality rates for AA women compared to EA women. Consequently, the purpose of this investigation was to examine and compare the impact of race on survival among cervical cancer patients in SC. Data from the SC Central Cancer Registry on all AA and EA cervical cancer patients in SC were analyzed for this investigation. All women greater than 19 years of age with a histopathologically-confirmed cervical neoplasm were included. Kaplan Meier survival curves were calculated and compared for each racial group using the log rank test statistic. Significant differences between races were noted for alcohol use, grade, histology, marital status, and vital status. AA women with cervical cancer had significantly decreased survival compared to EA women (49% vs. 66%, p < 0.01). This same trend was noted for all grade, histology, and stage types. We found significantly decreased survival among AA women with cervical cancer compared to EA women, which persisted even among AA and EA women with the same disease stage, grade, or histology. The causes of these disparities are most likely multi-faceted and interdependent. These findings emphasize the need for intervention into the myriad of factors ranging from the biological and genetic to the environmental and structural barriers impacting cervical cancer mortality.

Soil zinc content, groundwater usage, and prostate cancer incidence in South Carolina.

BACKGROUND: Prostate cancer (PrCA) incidence in South Carolina (SC) exceeds the national average, particularly among African Americans (AAs). Though data are limited, low environmental zinc exposures and down-regulation of prostatic zinc transporter proteins among AAs may explain, in part, the racial PrCA disparity. METHODS: Age-adjusted PrCA rates were calculated by census tract. Demographic data were obtained from the 1990 census. Hazardous waste site locations and soil zinc concentrations were obtained from existing federal and state databases. A geographic information system and Poisson regression were used to test the hypothesis that census tracts with reduced soil zinc concentrations, elevated groundwater use, or more agricultural or hazardous waste sites had elevated PrCA risks. RESULTS: Census tracts with high groundwater use and low zinc concentrations had higher PrCA rate ratios (RR: 1.270; 95% confidence interval: 1.079, 1.505). This effect was not more apparent in areas populated primarily by AAs. CONCLUSION: Increased PrCA rates were associated with reduced soil zinc concentrations and elevated groundwater use, although this observation is not likely to contribute to SC's racial PrCA disparity. Statewide mapping and statistical modeling of relationships between environmental factors, demographics, and cancer incidence can be used to screen hypotheses focusing on novel PrCA risk factors.

The impact of socioeconomic status on survival after cancer in the United States : findings from the National Program of Cancer Registries Patterns of Care Study.

BACKGROUND: Understanding the ways in which socioeconomic status (SES) affects mortality is important for defining strategies to eliminate the unequal burden of cancer by race and ethnicity in the United States. METHODS: Disease stage, treatment, and 5-year mortality rates were ascertained by reviewing medical records, and SES was determined by analyzing income and education at the census tract level for 4844 women with breast cancer, 4332 men with prostate cancer, and 4422 men and women with colorectal cancer who were diagnosed in 7 U.S. states in 1997. RESULTS: Low SES was associated with more advanced disease stage and with less aggressive treatment for all 3 cancers. The hazard ratio (HR) for 5-year all-cause mortality associated with low SES was elevated after a diagnosis of breast cancer when the analysis was adjusted for age (HR, 1.59; 95% confidence interval [CI], 1.35-1.87). Adjustment for mediating factors of race/ethnicity, comorbid conditions, cancer stage, and treatment reduced the association. The age-adjusted mortality risk associated with low SES was elevated after a diagnosis of prostate cancer (HR, 1.33; 95% CI, 1.13-1.57), and multivariate adjustments for mediating factors also reduced that association. There was less association between SES and mortality after a diagnosis of colorectal cancer. For all 3 cancer sites, low SES was a much stronger predictor of mortality among individuals aged <65 years and among individuals from racial/ethnic minority groups. CONCLUSIONS: The current results indicated that low SES is a risk factor for all-cause mortality after a diagnosis of cancer, largely because of a later stage at diagnosis and less aggressive treatment. These findings support the need to focus on SES as an underlying factor in cancer disparities by race and ethnicity.

Survival difference between non-Hispanic black and non-Hispanic white women with localized breast cancer: the impact of guideline-concordant therapy.

OBJECTIVES: This study examined the impact of guideline-concordant therapy on the survival difference between non-Hispanic black (NHB) and non-Hispanic white (NHW) women with localized breast cancer. METHODS: Data analyzed were from the CDC's NPCR Patterns of Care study in which seven population-based state cancer registries participated. We randomly selected 2,362 women who were diagnosed with a first primary localized breast cancer in 1997. Data were abstracted from hospital records, supplemented by information from physician offices and by linkages with state vital records and the National Death Index database. RESULTS: NHB women were more likely than NHW women to receive breast conserving surgery without radiation therapy. In addition, the percentage of NHB women with hormone receptor-positive tumors who received hormonal therapy was lower than that of NHW women. Among those with a tumor size > 3 cm, NHB women were more likely than NHW women to receive multiagent chemotherapy. After controlling for age, the risk of dying from all causes of death was 2.35 times as high for NHB women compared to NHW women. Controlling for treatment further reduced black-white difference in survival with adjustment for sociodemographic and clinical variables. CONCLUSION: NHB women were less likely than NHW women to receive guideline-concordant radiation therapy after breast conserving therapy and hormonal therapy but were more likely to receive chemotherapy. Racial differences in treatment contribute significantly to the worse survival of NHB women compared with NHW women.

Cancer in Appalachia, 2001-2003.

BACKGROUND: Researchers have not been able to examine cancer incidence rates in Appalachia because high-quality data have not been uniformly available across the region. This study is the first to report cancer incidence rates for a large proportion of the Appalachian population and describe the differences in incidence rates between Northern, Central, and Southern Appalachia. METHODS: Forty-four states and the District of Columbia provided information for the diagnosis years 2001 through 2003 from cancer registries that met high-quality data criteria. Eleven of 13 states with counties in Appalachia, covering 88% of the Appalachian population, met these criteria; Virginia and Mississippi were included for 2003 only. SEER(*)Stat was used to calculate age-adjusted rates per 100,000 population and 95% gamma confidence limits. RESULTS: Overall, cancer incidence rates were higher in Appalachia than in the rest of the US; the rates for lung, colon/rectum, and other tobacco-related cancers were particularly high. Central Appalachia had the highest rates of lung (men: 143.8; women: 75.2) and cervical cancer (11.2)-higher than the other 2 regions and the rest of the US. Northern Appalachia had the highest rates for prostate, female breast, and selected other sites, and Southern Appalachia had the lowest overall cancer incidence rates. CONCLUSIONS: Cancer incidence rates in Appalachia are higher than in the rest of the US, and they vary substantially between regions. Additional studies are needed to understand how these variations within Appalachia are associated with lifestyle, socioeconomic factors, urban/rural residence, and access to care.

Head and neck cancer disparities in South Carolina: descriptive epidemiology, early detection, and special programs.

Recognizing that relatively easily detected precancerous lesions precede many cancers, there is a need to investigate the effectiveness of early interventions on the reduction of incidence rates in well-designed large randomized control trials. If early detection can reduce mortality rates of OPCA, evaluation of the capacity of dentists and physicians to screen or detect precancerous lesions related to oral cancers may have merit. Presently, there is a paucity of research regarding ecological barriers in the healthcare system, and improving access to adequate dental and medical care among the rural minority population in South Carolina certainly deserves emphasis. Additional research, specific to South Carolina, which includes comprehensive assessment of multiple social, behavioral, and biological factors, is needed. Interdisciplinary collaboration will be particularly important to dissect key factors contributing to the racial disparities observed in South Carolina. These differences should be taken into account while recommending and implementing public health strategies for the control of these cancers.

Breast cancer disparities in South Carolina: early detection, special programs, and descriptive epidemiology.

A discrepancy exists between mortality and incidence rates between African-American and European-American women in South Carolina. The relationship between tumor grade and the estrogen/ progesterone receptor status is different in African-American and European-American women. African-American women with breast cancer should be encouraged to participate in clinical trials, with the goal of identifying biological factors that might facilitate the detection of tumors at an earlier stage and the development of more effective therapies. The most important of our goals is to design studies to reduce the incidence of the disease and interventions to improve survival and quality of life. The importance of participation in research cannot be overstated. Reproductive factors such as early pregnancy and multiple pregnancies are strongly related to breast cancer risk, however, promotion of these factors as a "prevention strategy," clearly does not lead to cogent, comprehensive public health messages. Data from ecological and migrant studies point clearly to other factors that may be important such as diet. Additional research around primary prevention strategies is needed. In addition, yearly mammograms (secondary prevention) are recommended for women over 50 years old or those with relatives who have developed breast cancer. The Best Chance Network, as a provider of screenings to low-income, uninsured women, has helped to narrow the racial gap in screening that otherwise might exist (see Figures 3 and 4) to a large extent. The determination for timing of surgery after diagnosis needs additional consideration. For example, factors such as effective screening in younger women, timing of screening and surgery in relationship to the ovulatory cycle, and season of screening and surgery may have a great impact on outcomes and may offer some insight into the process of carcinogenesis and therapeutic efficacy. Research into this area is so novel that the impact on possible ethnic disparities is completely unknown. The South Carolina Cancer Disparities Community Network (SCCDCN) has identified the following areas as potential research foci: Identification of small media interventions as an effective strategy to motivate targeted populations, especially those least likely to seek screening for breast cancer and those least likely to participate in research programs (African-Americans). Utilization of breast cancer survivors, self-identified as community natural helpers, can share their experiences with their church congregation. A replication of such a program in South Carolina has great potential because of the strong presence of the church, especially in rural parts of the state. Programs that closely integrate religion with screening women for breast cancer are promising in this state. Development of a mammography registry whereby information on all mammography procedures would be collected within a single database system (much like a central cancer registry). This would aid in identifying population groups that could be targeted for special programs and in the examination and exploration of the most appropriate modalities of detection. Such a resource could also be a useful tool to encourage screening. Thus, this focus area has the potential to benefit epidemiologic and health promotion research on many different levels. Additional breast cancer screening methods should not be overlooked as a potential research focus. Mammography is not the only valid screening method for breast cancer. Magnetic resonance imaging has shown some promise for screening among women with a genetic predisposition for cancer. Another promising avenue is thermography. Because detection rates may depend on age, ethnicity, and breast mammographic characteristics, women for whom regular screening methods do not detect their cancers (e.g. older age, African-American ethnicity, dense breasts) must be identified and other screening methods promoted within these populations. The above-mentioned mammography registry would support this type of research.

Rationale and design of the National Program of Cancer Registries' Breast, Colon, and Prostate Cancer Patterns of Care Study.

BACKGROUND: Investigators from the Centers for Disease Control and Prevention (CDC), National Program of Cancer Registries (NPCR), are collaborating with public health professionals from seven states and the District of Columbia to conduct the Patterns of Care study to assess the quality of cancer data and to determine whether stage-specific treatments are being carried out. METHODS: To assess the quality and completeness of cancer care data in the United States, trained staff from the Patterns of Care study are abstracting medical records to obtain detailed clinical data on treatment, tumor characteristics, stage at diagnosis, and demographics of representative samples of patients diagnosed with breast, colon, and prostate cancer. Altogether staff from each of the eight participating cancer registries will abstract 500 cases of breast, prostate, and colon/rectum/anus cancer for the CONCORD study and an additional 150 cases of localized breast cancer, 100 cases of stage III colon cancer, and 100 cases of localized prostate cancer for the Patterns of Care study. Chi-square tests will be used to compare routine registry data with re-abstracted data. The investigators will use logistic regression techniques to describe the characteristics of patients with localized breast and prostate cancer and stage III colon cancer. Age, race, sex, type of insurance, and comorbidity will be examined as predictors of the use of those treatments that are consistent with consensus guidelines. The investigators plan to use data from the CONCORD study to determine whether treatment factors are the reason for the reported differences between relative survival rates in the United States and Europe. CONCLUSIONS: Results from the methodology used in the Patterns of Care study will provide, for the first time, detailed information about the quality and completeness of stage and treatment data that are routinely collected by states participating in the NPCR. It will add significantly to our understanding of factors that determine receipt of treatment in compliance with established guidelines. As part of the CONCORD study, it will also examine differences in survival among cancer patients with breast, prostate, and colon/rectum/anus cancers in the United States and Europe.