Limburg Paul J, Vierkant Robert A, Fredericksen Zachary S, Leibson Cynthia L, Rizza Robert A, Gupta Amit K, Ahlquist David A, Melton Lee J, Sellers Thomas A, Cerhan James R
Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
Am J Gastroenterol. 2006 Aug;101(8):1872-9. doi: 10.1111/j.1572-0241.2006.00725.x. Epub 2006 Jun 22.
Patients with type 2 diabetes mellitus (DM) may be at increased colorectal cancer (CRC) risk. However, existing data are inconsistent. We investigated CRC risks, overall and by anatomic subsite, within a population-based inception cohort of clinically confirmed type 2 DM subjects.
All residents of Rochester, Minnesota who first met standardized criteria for type 2 DM from 1970 to 1994 (997 men and 978 women) were identified and followed forward in time until emigration, death, or December 31, 1999. Incident CRC cases were identified by review of inpatient and outpatient medical records. Standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were estimated to compare CRC incidence within the type 2 DM inception cohort with previously published rates for the Rochester general population.
Over 19,158 person-years of follow-up, 51 incident CRC cases were identified within the type 2 DM cohort, while only 36.8 cases were expected (SIR = 1.39, 95% CI 1.03-1.82). Among men, type 2 DM was associated with increased overall (SIR = 1.67, 95% CI 1.16-2.33) and proximal (SIR = 1.96, 95% CI 1.16-3.10) CRC risks; distal CRC risk was also increased, but the point estimate was not statistically significant (SIR = 1.43, 95% CI 0.82-2.32). Among women, type 2 DM was not a risk factor for overall, proximal, or distal CRC (SIR = 1.03, 95% CI 0.60-1.66; SIR = 1.17, 95% CI 0.58-2.09; and SIR = 0.74, 95% CI 0.24-1.72, respectively). Within the type 2 DM cohort, current and former cigarette smokers were at higher CRC risk (SIR = 1.77, 95% CI 1.24-2.47) than never smokers (SIR = 0.99, 95% CI 0.57-1.61) and the interaction between type 2 DM and cigarette smoking status was statistically significant (p= 0.05).
In this population-based, retrospective cohort study, clinically confirmed type 2 DM was associated with increased CRC risk, predominantly among men. Cigarette smoking appeared to positively modify DM-associated CRC risk, which to our knowledge has not been previously reported. These data suggest that further investigation of potential interactions between endogenous and exogenous factors involved in colorectal carcinogenesis may help to clarify the magnitude and extent of CRC risk experienced by persons with type 2 DM.
2型糖尿病（DM）患者患结直肠癌（CRC）的风险可能会增加。然而，现有数据并不一致。我们在一个基于人群的初发队列中，对临床确诊的2型DM患者的CRC风险进行了总体及按解剖部位的调查。
确定了明尼苏达州罗切斯特市所有在1970年至1994年间首次符合2型DM标准的居民（997名男性和978名女性），并对其进行随访，直至移民、死亡或1999年12月31日。通过查阅住院和门诊病历确定新发CRC病例。估计标准化发病率（SIR）和95%置信区间（CI），以比较2型DM初发队列中的CRC发病率与罗切斯特普通人群先前公布的发病率。
在超过19158人年的随访中，2型DM队列中确定了51例新发CRC病例，而预期仅为36.8例（SIR = 1.39，95%CI 1.03 - 1.82）。在男性中，2型DM与总体（SIR = 1.67，95%CI 1.16 - 2.33）及近端（SIR = 1.96，95%CI 1.16 - 3.10）CRC风险增加相关；远端CRC风险也增加，但点估计无统计学意义（SIR = 1.43，95%CI 0.82 - 2.32）。在女性中，2型DM不是总体、近端或远端CRC的危险因素（SIR分别为1.03，95%CI 0.60 - 1.66；SIR = 1.17，95%CI 0.
