Identifying Geospatial Patterns of Aggressive Breast Cancer Incidence Using North State as a Model

摘要

Breast cancer is a complex disease influenced by multiple factors, and overall survival improvements are hindered by aggressive and advanced cases that are not well understood. Our objective was to evaluate geographic variability in the prevalence of late stage metastatic breast cancer and total breast cancers in North Carolina. NC represents a state with geographic variability in cancer incidence, demographics, and environmental factors, making it an ideal location for this study. We collected breast cancer patient data from the North Carolina Central Cancer Registry for years 2009-2014, and derived summary staging was used to classify cases as in situ, localized, regional, or distant/metastatic. Total incidence data was averaged to reflect a 6-year incidence average. Age-adjusted standardized incidence ratios (SIRs) and 95% confidence intervals were then calculated for total breast cancer and distant/metastatic breast cancer for each county in NC. Prior studies have identified NC as part of a high breast cancer incidence region in the US, but there remains insufficient granular analysis such as the described methodology. We identified several counties in North Carolina with statistically significant high SIRs for breast cancer on the outer western and eastern regions of the state. For distant/metastatic breast cancers, statistically significant high SIRs were located primarily in the northeastern coastal region. We intend to investigate these counties further in correlation with environmental factors, including industry-derived, air, soil, and water contamination, and a variety of social, behavioral, and demographic factors. Overall our data identifies differential regions of NC with higher than expected incidence of total versus aggressive breast cancers, suggesting that different demographic or environmental factors may play a role in the observed variability. This work was supported by Duke Cancer Institute Cancer & Environment Funds and NIEHS T32-ES021432.