Geographic Disparities in Colorectal Cancer Survival

描述（由申请人提供）：结直肠癌（CRC）是美国第四大常见癌症，也是癌症死亡的第二大原因。尽管CRC发病率有所下降，但在过去几十年中，诊断后的生存率仅略有提高。尽管环境背景在健康、疾病和行为中发挥着重要作用，但大多数关于CRC生存的研究在很大程度上忽略了地理差异和区域层面社会经济条件的重要性，而这些社会经济条件与CRC筛查、诊断时的CRC阶段以及许多其他癌症的生存有关。生活在社会经济条件较差地区的结直肠癌患者的生存率低于生活在较富裕地区的结直肠癌患者；然而，这些区域水平的因素对结直肠癌存活的影响机制尚不清楚。拟议的基于人群的前瞻性研究的修订应用有三个具体目的。目的1)利用相关的监测、流行病学和最终结果(SEER)-医疗保险数据，对超过10万名66岁或以上诊断为结直肠癌的男性和女性，基于小地理区域的次县（人口普查区）水平，确定美国结直肠癌生存率的地理差异程度。目的2)确定66岁及以上人群中较高的地区社会经济剥夺在多大程度上可以解释较低的结直肠癌生存率。目的3)确定高地区社会经济剥夺与66岁及以上人群较低CRC生存率相关的潜在介导途径，即a)患者特征，b)医生和医院特征，c)肿瘤特征，d)接受的治疗类型，以及e)诊断后对CRC进行监测以检测复发和转移。将发展一个多层空间模型，以处理拟议研究的具体目标。我们将使用以下现有数据来源：1)NCI SEER项目1992-2005年的数据（生存率、患者特征、治疗类型、肿瘤特征）；2)与SEER数据相关的1991-2005年医疗保险数据（患者特征、治疗类型、诊断后监测）；3) 1991-2005年服务提供者档案数据（医院和医生特征），4)1990-2005年人口普查数据（地区剥夺措施），以及5)医疗保险当前受益人调查数据。高级贝叶斯空间分析的CRC生存将进行，并将使用地理信息系统来显示结果。我们的研究将增加对区域层面的社会经济剥夺对CRC生存的重要作用机制的理解和确定。此外，这项研究将有助于提供针对特定地理区域的机会，利用基于证据的方法在当地分配资源和干预措施，以提高结直肠癌的存活率，从而减少与生活在社会经济贫困地区相关的健康差异。公共卫生相关性：结直肠癌是癌症死亡的第二大原因。为了减少结直肠癌后生存的地域差异，并制定和实施可针对当地的干预措施，必须确定低于预期生存的原因。

DESCRIPTION (provided by applicant): Colorectal cancer (CRC) is the fourth most common cancer in the United States and the second leading cause of cancer deaths. Despite declines in CRC incidence rates, survival following diagnosis has improved only modestly over the past few decades. Even though environmental contexts play an important role in health, disease, and behavior, most studies about CRC survival have largely ignored the geographic variation and importance of area-level socioeconomic conditions that have been associated with CRC screening, CRC stage at diagnosis, and with the survival of many other cancers. CRC patients who live in areas with worse socioeconomic conditions have decreased survival than those who live under more affluent conditions; however, the mechanisms by which these area-level factors exert their influence on CRC survival remain unclear. This amended application of the proposed population-based, prospective study has three specific aims. Aim 1) Determine the extent of the geographic variation of CRC survival across the United States based on small geographic areas at the sub-county (census-tract) level using the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare data for over 100,000 men and women aged 66 or older diagnosed with CRC. Aim 2) Determine the extent to which lower CRC survival can be explained by higher area socioeconomic deprivation among persons age 66 and older. Aim 3) Identify potential mediating pathways by which higher area socioeconomic deprivation is associated with lower CRC survival among persons age 66 and older, namely a) patient characteristics, b) physician and hospital characteristics, c) tumor characteristics, d) type of treatment received, and e) surveillance for CRC after diagnosis to detect recurrence and metastases. A multilevel spatial model will be developed to address the specific aims of the proposed study. We will use the following existing data sources: 1) 1992-2005 data from NCI's SEER program (survival, patient characteristics, type of treatment, tumor characteristics); 2) 1991-2005 Medicare data (patient characteristics, type of treatment, surveillance after diagnosis) which is linked to the SEER data; 3) 1991-2005 data from the Provider of Services File (hospital and physician characteristics), 4) 1990-2005 census data (area deprivation measures), and 5) Medicare Current Beneficiary Survey data. Advanced Bayesian spatial analyses of CRC survival will be performed and a geographic information system will be used to display the results. Our study will increase understanding of and identify important mechanisms of the role of area-level socioeconomic deprivation on CRC survival. In addition, this study will help provide opportunities for targeting specific geographic areas to allocate resources and interventions locally to improve CRC survival using evidence- based approaches, thereby reducing health disparities associated with living in socioeconomically deprived areas. PUBLIC HEALTH RELEVANCE: Colorectal cancer is the second leading cause of cancer deaths. To reduce geographic disparities in survival following colorectal cancer and to develop and implement interventions that can be targeted locally, it is imperative to identify reasons for lower-than-expected survival.