Neighborhood Effects on Colorectal Cancer Incidence and Stage of Diagnosis

本项目是一项纵向观察性研究，纳入区域和个体水平变量，以评估社区环境对结直肠癌发病率和诊断阶段的影响。结直肠癌（CRC）是美国癌症相关死亡的第二大原因。少数民族人口受到的影响不成比例，而且已知会产生不良后果。尽管存在筛查指南，但很大一部分病例仍在晚期才被诊断出来。由于结直肠癌潜伏期长，暴露于有害的社会环境以及其他危险因素预示着预后不良。在这项研究中，对一个概念模型进行了调整，以供使用，该模型描述了在多个领域中因获取资源的途径不同而暴露于风险因素的不同程度，从而导致一定程度的社区健康。此外，癌症登记和人口普查数据的二次分析规避了主要数据收集的高昂成本，特别是对于小型研究项目。这项多层次和生态研究的具体目的是研究背景变量与块组和普查区水平的CRC病例之间的关系，同时在多个水平上进行早期/晚期诊断，并利用SaTScan中的泊松模型研究1998-2003年休斯顿CRC发病率和晚期诊断的时空变化趋势。人口普查得出的现成的社会环境变量，如职业阶级、教育水平、贫困、过度拥挤、语言隔离等，将成为自变量。将CRC病例和早期/晚期诊断作为因变量进行分析。解决癌症病因差异是美国国立卫生研究院和美国国立癌症研究所高度重视的领域，对现有数据集进行二次分析是R03机制和项目公告的重要要求。作为全国第四大城市的地方卫生部门，我们负责确定有需要和缺乏资源的地理区域，并制定适当的干预战略来解决这些问题。我们预计，我们的结果将很容易被翻译到其他大城市，类似于我们的，不同的人口。这项研究将帮助我们更好地理解癌症差异，并利用生态、多层次和地理空间分析技术梳理出在不良结果中起作用的社会环境因素。

DESCRIPTION (provided by applicant): Project Summary The proposed project is a longitudinal, observational study incorporating both area and individual level variables to assess contextual effects of the neighborhood on colorectal cancer incidence and stage of diagnosis. Colorectal cancer (CRC) is the second highest cause of cancer related deaths in the US. Minority populations are disproportionately affected and are known to have adverse outcomes. Although screening guidelines exist, a large proportion of cases are still being diagnosed at late stages. Since CRC has a long latency period, exposure to a deleterious social environment along with other risk factors portend poor prognosis. For this study, a conceptual model depicting the varying levels of exposure to risk factors, in multiple domains, with differing pathways in access to resources, resulting in a certain level of community health was adapted for use. In addition, secondary analysis of Cancer Registry and Census data circumvents the prohibitive costs of primary data collection, particularly for small research projects. The specific aims of this multilevel and ecological study are to examine relationships between contextual variables and the cases of CRC at block group and census tract level, early/late stage diagnosis at multiple levels simultaneously and also to examine the geographic variation in spatial and temporal trends in CRC incidence and late stage diagnosis for the years 1998-2003 in Houston, using Poisson models in SaTScan. Census derived readily available social environment variables such as occupational class, education level, poverty, overcrowding, linguistic isolation etc. will be the independent variables. CRC cases and early/late stage diagnosis will be analyzed as the dependent variables. Addressing disparities in cancer etiology is a high priority area for National Institute of Health and National Cancer Institute and secondary analysis of existing datasets is an important requirement of the R03 mechanism and the program announcement. As the local health department in the fourth largest city in the country, we are responsible for identifying geographic areas of need and lack of access to resources and developing appropriate intervention strategies to address them. We anticipate that our results will be easily translatable to other large cities, similar to ours, with diverse populations. This study will help us better understand cancer disparities and tease out the socio-environmental factors that play a role in adverse outcomes using ecological, multilevel and geospatial analytic techniques. PUBLIC HEALTH RELEVANCE: Project Narrative Public Health Relevance: Our study will result in greater understanding of the distribution, etiology, spatio-temporal patterns of colorectal cancer (CRC) in Houston, the fourth largest city in the country. It will also identify areas of the city with greater than expected rates. This will help ascertain important social, environmental and behavioral risk factors that play a role in late stage diagnosis of this disease. This study will not only help inform science, but also community health professionals in designing programs to address some of the modifiable factors, in settings similar to ours. In addition, the policy implications at various levels of the government such as the City and State level and translation of research into practice by enhancing health promotion, health literacy and CRC screening in high risk areas are some of the potential benefits that will be achieved.