Holly Samociuk

Geographic differences in invasive and in situ breast cancer incidence according to precise geographic coordinates, Connecticut, 1991–95

To evaluate geographical variation of invasive and in situ breast cancer incidence rates using precise geographical coordinates for place of residence at diagnosis, latitude‐longitude coordinates pertaining to 10,601 invasive and 1,814 in situ breast cancers for Connecticut women, 1991–95, were linked to US Census information on the 2,905State census block groups. A spatial scan statistic was used to detect geographic excess or deficits in incidence and test the statistical significance of results, without prior assumptions about the size or location of such areas. The age adjusted invasive cancer incidence rate was 165.3/100,000 women/year. The spatial scan statistic identified 3 places with significantly low incidence rates and 4 places where rates were significantly high. The most probable location of low incidence was rural northeastern Connecticut where risk of disease, relative to elsewhere around the state, was 0.70 (p = 0.0001); the most probable place of elevated incidence was north central Connecticut where a relative risk of 1.34 (p = 0.002) was observed. Incidence of in situ disease was estimated to be significantly high for north central Connecticut (RR = 1.84; p = 0.0001). Geographic differences of invasive and in situ breast cancer incidence were observed. Examining cancer events at the lowest available level of data aggregation is beneficial in highlighting localized rate variations. Such information may enable public health officials to target additional resources for promoting breast cancer screening to specific locations.

Effects of study area size on geographic characterizations of health events: Prostate cancer incidence in Southern New England, USA, 1994–1998

BackgroundWe consider how representations of geographic variation in prostate cancer incidence across Southern New England, USA may be affected by selection of study area and/or properties of the statistical analysis.MethodA spatial scan statistic was used to monitor geographic variation among 35,167 incident prostate cancer cases diagnosed in Massachusetts, Connecticut and Rhode Island from 1994 to 1998, in relation to the 1990 populations of men 20+ years of age living in that region. Results from the combined-states analysis were compared to those from single-states. Impact of scanning procedures set to examine up to 50% or no more than10% of at-risk populations also was evaluated.ResultsWith scanning set to 50%, 5 locations in the combined-states analysis were identified with markedly distinct incidence rates. Fewer than expected cases were estimated for nearly all Connecticut, Rhode Island and West Central Massachusetts, whereas census tracts on and around Cape Cod, and areas of Southwestern Connecticut and adjacent to greater Boston were estimated to have yielded more than expected incidence. Results of single-state analyses exhibited several discrepancies from the combined-states analysis. More conservative scanning found many more locations with varying incidence, but discrepancies between the combined- and single-state analysis were fewer.ConclusionIt is important to acknowledge the conditional nature of spatial analyses and carefully consider whether a true cluster of events is identified or artifact stemming from selection of study area size and/or scanning properties.

Race-specific geography of prostate cancer incidence

BackgroundThis study evaluated geographic distribution of race-specific prostate cancer incidence in Connecticut and Massachusetts. This cross-sectional analysis of census and cancer registry data included records of 29,040 Whites and 1,647 African Americans diagnosed with incident prostate cancer between 1994 and 1998. A spatial scan statistic was used to detect and test significance of the geographic variation in race-specific incidence rates within the two-state area.ResultsSignificant geographic variation in age-adjusted incidence rates among both White and African American men was observed, with little overlap noted between distributions. Identified locations reflected patterns of residential segregation and socio-economic conditions. Among Whites, places with higher than expected incidence had higher socioeconomic status than places with lower than expected incidence. No discernable relationship between social indicators and rate variation among African Americans was evident.ConclusionDifferences in race-specific geographic distribution of prostate cancer incidence do not suggest a shared environmental etiology. Furtherstudyof genetic, behavioral and health carefactors affecting the occurrence and/or reporting of the disease is warranted. This study highlights the need for race- and geographic-specific interventions to better control disease within at-risk communities and for on-going analysis into social and contextual factors that contribute to observed disparities between African Americans and Whites in the occurrence of cancer.

Marital status and variability in cortisol excretion in postmenopausal women

Based on the premise that acute and chronic stresses stimulate and suppress cortisol secretion, respectively, and the hypothesis that marriage provides a buffer to stress, we tested whether extreme values of serum cortisol concentrations would be less likely in married women than in unmarried women. Three hundred women were recruited from two central Connecticut communities. Cortisol was measured in overnight urine samples using liquid chromatography-tandem mass spectrometry. Information on each subjects demographic characteristics, such as income and education level was collected. Mean log urinary cortisol was virtually identical in married and unmarried women, however, as predicted, the variance was significantly larger in the unmarried group (p=0.01). After adjustment for potential confounders, multivariate logistic regression still revealed that absolute deviation of log(10) cortisol from the mean was smaller for married versus unmarried women (p<0.01); deviation from the mean cortisol was also higher for non-working than working women. These results support the idea that marriage and employment reduce the extreme levels of cortisol secretion, and by extension, this may reflect differences in levels of stress in married and in working women compared to unmarried and non-working women.

Breast Cancer Surveillance using Gridded Population Units, Connecticut, 1992 to 1995

PURPOSE To assess geographic variation in invasive breast cancer across Connecticut using gridded population areas to enumerate cases and the population at-risk. METHODS The states land mass was divided into 5168, 1-by-1 square mile areas and the population of women, 20+ years of age, within each location was estimated by areal interpolation of the 1990 US Census Block Group STF-3A data file. Using information on breast cancer incidence, 1992 to 1995, from the Connecticut Tumor Registry, latitude-longitude coordinates for place of residence at the time of breast cancer diagnosis were determined for 8530 records and assigned to appropriate grid locations. A spatial scan statistic was used to detect variation in incidence and test the significance of observed differences across the state. Standardized Incidence Ratios (SIRs) described the proportional change in the age-adjusted breast cancer incidence rate across gridded locations. RESULTS The statewide age-adjusted invasive cancer incidence rate was 163.6/100,000 women/year. The spatial scan statistic identified three locations around Connecticut with significantly low incidence rates and four places where rates were significantly high. The most probable place of low incidence was rural Northeastern Connecticut where risk of disease, relative to elsewhere around the state, was 0.73 (p = 0.001). The most probable location of elevated incidence was a suburban location in Southwestern Connecticut with a relative risk of 2.02 (p = 0.001). CONCLUSIONS Visual representation of disease incidence and underlying populations at-risk according to gridded units provides a useful tool for assessing small area variation in disease patterns.

Light at night and breast cancer incidence in Connecticut: An ecological study of age group effects

The aim of this study was to test the prediction that within the state of Connecticut, USA, communities with high nighttime outdoor light level would have higher breast cancer incidence rates. Breast cancer cases were identified from the Connecticut Tumor Registry, the oldest within the United States, for years 2005 and 2009 and geocoded to the 829 census tracts in the state. Nighttime light level (LAN) was obtained from the Defense Meteorological Satellite Program (DMSP), 1996/97 satellite image, providing a 10-year lag. Regression models were used incorporating the LAN levels and census level data on potential confounders for the whole female population of the state, and for separate age groups. Light level emerged as a significant predictor of breast cancer incidence. After taking account of several potential confounders, the excess risk in the highest LAN level census tracts compared to the lowest was about 63% (RR=1.63; 95% CI=1.41, 1.89). The association of LAN with breast cancer incidence weakened with age; the association was strongest among premenopausal women.

Who's assessing tobacco use in cancer clinical trials?

INTRODUCTION Clinical trials that do not collect data on tobacco use/exposure may not adequately assess the efficacy and effectiveness of experimental treatments. METHODS A cross-sectional study of interventional trials cited on ClinicalTrials.gov was undertaken that inquired of Local Project Directors from Connecticut guiding studies of breast, prostate, or colorectal cancer chemotherapy (N = 68) whether their protocols measured tobacco use by trial participants. Information pertaining to 46 trials (68%) is reported here. All but 1 were multicentered trials enrolling patients around the country. RESULTS Only 3 trials (7%) reported routine collection of tobacco use information at baseline and no trial reported monitoring tobacco use during treatment follow-up. None of the 3 trials collecting tobacco data reported using exposure information in analysis of treatment effects. Survey respondents suggested that uncertainty about the relevance of tobacco exposure to therapeutic efficacy, ambivalence about how to incorporate such data into analyses, insufficient resources for collecting such information, and uncertainty about the validity of assessment methods might be reasons why tobacco use is not routinely assessed. DISCUSSION Additional studies that address a fuller range of cancers, therapies, disease states, and clinical environments are needed to fully define the extent of this data lapse. Providing clinicians and trialists with appropriate tools for tobacco use assessment and encouraging them to collect such information about patients during treatment and follow-up may offer a simple cost-effective way to improve the quality and consequences of cancer care for every patient.

Geography of breast cancer incidence according to age & birth cohorts

PURPOSE Geographic variation in breast cancer incidence across Connecticut was examined according to age and birth cohort -specific groups. METHODS We assigned each of 60,937 incident breast cancer cases diagnosed in Connecticut, 1986-2009, to one of 828 census tracts around the state. Global and local spatial statistics estimated rate variation across the state according to age and birth cohorts. RESULTS We found the global distribution of incidence rates across places to be more heterogeneous for younger women and later birth cohorts. Concurrently, the spatial scan identified more locations with significantly high rates that pertained to larger proportions of at-risk women within these groups. Geographic variation by age groups was more pronounced than by birth cohorts. CONCLUSION Geographic patterns of cancer incidence exhibit differences within and across age and birth cohorts. With the continued insights from descriptive epidemiology, our capacity to effectively limit spatial disparities in cancer will improve.