Keenan ResearchCentre, Li Ka Shing Knowledge Institute, andDivision of General Surgery, St. Michael's Hospital, University of Toronto, 30 Bond Street, Toronto, Ontario, Canada.
J Clin Oncol. 2012 Jul 20;30(21):2664-9. doi: 10.1200/JCO.2011.40.4772. Epub 2012 Jun 11.
We designed this study to evaluate the association of colonoscopy with colorectal cancer (CRC) death in the United States by site of CRC and endoscopist specialty.
We designed a case-control study using Surveillance, Epidemiology, and End Results (SEER)-Medicare data. We identified patients (cases) diagnosed with CRC age 70 to 89 years from January 1998 through December 2002 who died as a result of CRC by 2007. We selected three matched controls without cancer for each case. Controls were assigned a referent date (date of diagnosis of the case). Colonoscopy performed from January 1991 through 6 months before the diagnosis/referent date was our primary exposure. We compared exposure to colonoscopy in cases and controls by using conditional logistic regression controlling for covariates, stratified by site of CRC. We determined endoscopist specialty by linkage to the American Medical Association (AMA) Masterfile. We assessed whether the association between colonoscopy and CRC death varied with endoscopist specialty.
We identified 9,458 cases (3,963 proximal [41.9%], 4,685 distal [49.5%], and 810 unknown site [8.6%]) and 27,641 controls. In all, 11.3% of cases and 23.7% of controls underwent colonoscopy more than 6 months before diagnosis. Compared with controls, cases were less likely to have undergone colonoscopy (odds ratio [OR], 0.40; 95% CI, 0.37 to 0.43); the association was stronger for distal (OR, 0.24; 95% CI, 0.21 to 0.27) than proximal (OR, 0.58; 95% CI, 0.53 to 0.64) CRC. The strength of the association varied with endoscopist specialty.
Colonoscopy is associated with a reduced risk of death from CRC, with the association considerably and consistently stronger for distal versus proximal CRC. The overall association was strongest if colonoscopy was performed by a gastroenterologist.
本研究旨在评估美国结肠镜检查与结直肠癌（CRC）死亡的相关性，分析其与 CRC 发病部位和内镜医生专业的关系。
我们采用监测、流行病学和最终结果（SEER）-医疗保险数据设计了一项病例对照研究。我们从 1998 年 1 月至 2002 年 12 月期间确定了年龄在 70 至 89 岁之间、被诊断患有 CRC 且于 2007 年之前因 CRC 死亡的患者（病例）。我们为每个病例选择了三名未患有癌症的匹配对照者。对照者的参照日期为病例的诊断日期。我们将 1991 年 1 月至诊断/参照日期前 6 个月期间进行的结肠镜检查作为主要暴露因素。我们通过条件逻辑回归控制协变量，对病例和对照者的结肠镜检查暴露情况进行分层，按 CRC 发病部位进行比较。我们通过与美国医学协会（AMA）大师档案的链接确定内镜医生的专业。我们评估了结肠镜检查与 CRC 死亡之间的关联是否因内镜医生的专业而有所不同。
我们共确定了 9458 例病例（41.9%为近端，49.5%为远端，8.6%为未知部位）和 27641 名对照者。共有 11.3%的病例和 23.7%的对照者在诊断前 6 个月以上进行了结肠镜检查。与对照者相比，病例接受结肠镜检查的可能性较小（比值比 [OR]，0.40；95%置信区间，0.37 至 0.43）；远端 CRC（OR，0.24；95%置信区间，0.21 至 0.27）的相关性明显强于近端 CRC（OR，0.58；95%置信区间，0.53 至 0.64）。这种相关性的强度因内镜医生的专业而有所不同。
结肠镜检查与 CRC 死亡风险降低相关，且远端 CRC 的相关性明显强于近端 CRC。如果由胃肠病学家进行结肠镜检查，则总体相关性最强。
