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发病率下降，但在过去几十年中，诊断后的生存率仅略有改善。尽管环境背景在健康，疾病和行为中起着重要作用，但大多数关于CRC生存的研究在很大程度上忽略了与CRC筛查，诊断时的CRC阶段以及许多其他癌症的生存相关的地区社会经济条件的地理差异和重要性。生活在社会经济条件较差地区的CRC患者的生存率低于生活在富裕地区的患者;然而，这些地区因素对CRC生存率产生影响的机制尚不清楚。这项拟议的基于人群的前瞻性研究的修订申请有三个具体目标。目的1）使用相关的监测、流行病学和最终结果（SEER）-医疗保险数据，基于子县（人口普查区）水平的小地理区域，确定美国各地CRC生存率的地理变异程度，这些数据针对超过100，000名66岁或以上诊断为CRC的男性和女性。目的2）确定CRC存活率较低的程度可以解释为66岁及以上人群中较高的社会经济贫困。目的3）确定潜在的介导途径，通过该途径，较高的地区社会经济贫困与66岁及以上人群中较低的CRC生存率相关，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CRC以检测复发和转移。将建立一个多层次的空间模型，以解决拟议研究的具体目标。我们将使用以下现有的数据来源：1）1992-2005年的数据来自NCI的SEER计划（生存率、患者特征、治疗类型、肿瘤特征）; 2）1991-2005年医疗保险数据（患者特征、治疗类型、诊断后监测），与SEER数据相关联; 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），5）医疗保险当前受益人调查数据。将对CRC生存率进行高级贝叶斯空间分析，并使用地理信息系统显示结果。我们的研究将增加理解和确定区域一级的社会经济剥夺对CRC生存的作用的重要机制。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，使用循证方法提高CRC生存率，从而减少与生活在社会经济贫困地区相关的健康差距。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，并制定和实施可针对当地的干预措施，必须确定生存率低于预期的原因。

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.