Geographic Disparities in Colorectal Cancer Survival

简介(申请人提供)：结直肠癌(CRC)是美国第四大常见癌症，也是导致癌症死亡的第二大原因。尽管结直肠癌的发病率有所下降，但在过去的几十年里，确诊后的存活率仅略有改善。尽管环境在健康、疾病和行为中扮演着重要的角色，但大多数关于结直肠癌存活率的研究在很大程度上忽略了地区层面的社会经济条件的地理差异和重要性，这些条件与结直肠癌筛查、诊断时的结直肠癌阶段以及许多其他癌症的存活率相关。生活在社会经济条件较差地区的结直肠癌患者的存活率低于生活在较富裕条件下的患者；然而，这些地区因素对结直肠癌存活率的影响机制尚不清楚。这项拟议的以人口为基础的前瞻性研究的修订应用有三个具体目标。目的1)使用关联监测、流行病学和最终结果(SEER)--针对100,000多名年龄在66岁或以上的被诊断为结直肠癌的男性和女性的医疗保险数据，确定全美结直肠癌存活率的地理差异程度。目的2)确定66岁及以上人群中较高的社会经济剥夺程度可以在多大程度上解释结直肠癌生存率较低的原因。目的3)确定在66岁及以上人群中，较高地区的社会经济剥夺与较低的结直肠癌生存率相关的潜在中介途径，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)诊断后监测结直肠癌以发现复发和转移。将开发一个多层次空间模型，以满足拟议研究的具体目标。我们将使用以下现有数据来源：1)1992-2005年来自NCI SEER计划的数据(存活率、患者特征、治疗类型、肿瘤特征)；2)1991-2005年与SEER数据链接的联邦医疗保险数据(患者特征、治疗类型、确诊后监测)；3)1991-2005年来自服务提供者档案的数据(医院和医生特征)；4)1990-2005年人口普查数据(区域剥夺措施)，以及5)联邦医疗保险当前受益人调查数据。将对CRC存活率进行高级贝叶斯空间分析，并将使用地理信息系统显示结果。我们的研究将增加对地区层面的社会经济剥夺对结直肠癌生存的作用的理解和确定重要的机制。此外，这项研究将有助于提供机会，针对特定的地理区域，在当地分配资源和干预措施，利用循证方法改善儿童的生存，从而减少与生活在社会经济贫困地区的健康差距。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率的地理差异，并制定和实施可在当地有针对性的干预措施，必须找出低于预期的生存率的原因。

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.