Introduction: Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the United States (U.S.). Mississippi has the highest rate of CRC incidence in the U.S. and has large populations of black and white individuals, allowing for studies of racial disparities. Methods: We conducted an ecological study using the county as the unit of analysis. CRC incidence data at the county level for black and white populations in Mississippi, covering the years 2003 to 2020, were retrieved from the Mississippi Cancer Registry. Age-adjusted incidence rate differences and their corresponding 95% confidence intervals (CIs) were then calculated for these groups. Getis–Ord Gi* hot and cold spot analysis of CRC incidence rate racial disparities was performed using ArcGIS Pro. We used global ordinary least square regression and geographically weighted regression (MGWR version 2.2) to identify factors associated with racial differences in CRC incidence rates. Results: Age-adjusted CRC incidence rate in the black population (median = 58.12/100,000 population) and in the white population (median = 46.44/100,000 population) varied by geographical area. Statistically significant racial differences in CRC incidence rates were identified in 28 counties, all of which showed higher incidence rates among the black population compared to the white population. No hot spots were detected, indicating that there were no spatial clusters of areas with pronounced racial disparities. As a post hoc analysis, after considering multicollinearity and a directed acyclic graph, a parsimonious multiple regression model showed an association (β = 0.93, 95% CI: 0.25, 1.62) indicating that a 1% increase in food insecurity was associated with a 0.93/100,000 differential increase in the black–white CRC incidence rate. Geographically weighted regression did not reveal any local patterns in this association. Conclusions: Black–white racial disparities in CRC incidence were found in 28 counties in Mississippi. The county-level percentage of food insecurity emerged as a possible predictor of the observed black–white racial disparities in CRC incidence rates. Individual-level studies are needed to clarify whether food insecurity is a driver of these disparities or a marker of systemic disadvantage in these counties.
引言：结直肠癌是美国第三大常见确诊癌症。密西西比州拥有全美最高的结直肠癌发病率，且同时包含大量黑人和白人群体，为种族差异研究提供了条件。方法：本研究以县为分析单位开展生态学研究。从密西西比州癌症登记处获取2003年至2020年该州县级黑人与白人结直肠癌发病率数据，计算年龄调整发病率差异及其95%置信区间。运用ArcGIS Pro软件进行结直肠癌发病率种族差异的Getis-Ord Gi*热点冷点分析，并采用全局普通最小二乘回归与地理加权回归（MGWR 2.2版）识别结直肠癌发病率种族差异的相关因素。结果：黑人群体（中位数58.12/10万）与白人群体（中位数46.44/10万）的年龄调整结直肠癌发病率存在地域差异。在28个县中发现具有统计学意义的种族差异，所有差异均表现为黑人群体发病率高于白人群体。未检测到热点区域，表明不存在种族差异显著的空间聚集区。事后分析显示，在考虑多重共线性与有向无环图后，简约多元回归模型提示食物不安全比例每增加1%，黑人与白人结直肠癌发病率差异将扩大0.93/10万（β=0.93，95%CI：0.25-1.62）。地理加权回归未发现该关联存在局部空间模式。结论：密西西比州28个县存在结直肠癌发病率的黑白种族差异。县级食物不安全比例可能是观测到的结直肠癌发病率种族差异的预测因子，需通过个体水平研究进一步明确食物不安全是导致这些差异的驱动因素，还是反映这些县系统性劣势的标志。
肿瘤(癌症)患者之家