Meyer Peter, Zuern Christine, Hermanns Norbert, Haak Thomas
Institute of Molecular Medicine, Munich, Germany.
J Carcinog. 2007 Sep 26;6:14. doi: 10.1186/1477-3163-6-14.
Increasing evidence indicates that type 2 diabetic patients are at elevated risk for developing different kinds of cancers. However, diabetes mellitus may be a protective factor for prostate cancer since both were found to be negatively associated. Based on the same genetic background, parents of diabetic patients might show similar risks concerning cancers.
We conducted a case-control study, where familiy history of 794 type 2 diabetic cases and 775 non-diabetic controls was ascertained. Then, we expanded our study up to 801 type 2 diabetic cases and 1267 non-diabetic controls.
Concerning the 794 type 2 diabetic patients and 775 controls, we observed that cancer of cervix uteri was elevated among mothers of controls (odds ratio (OR) 0.19; 95% confidence interval (CI) 0.02 to 0.88; p = 0.033). Mothers of diabetic patients showed an increased history of cancers of the liver and biliary tract (OR 5.23; 95% CI 1.87 to 19.9; p = 0.0009) and stomach (OR 3.84; 95% CI 1.47 to 12.4; p = 0.0049). Pancreatic cancers were found to be elevated in fathers of diabetic patients (OR 4.92; 95% CI 1.07 to 46.7; p = 0.039). Most notably, a lower number of prostate cancers was observed in fathers of diabetic patients (OR 0.47; 95% CI 0.22 to 0.94; p = 0.032). Since diabetic patients were 14.3 years older than the controls, higher levels of cancer history among parents of diabetic patients would have been expected. Thus, the observed lower level of history of prostate cancer can be regarded as highly reliable.The analysis of 801 type 2 diabetics and 1267 controls showed that cancer of stomach was elevated among mothers of controls (OR 2.67; p = 0.0106). In addition, stomach cancers were found to be elevated in fathers of diabetic patients (OR 2.10; p = 0.0141). In accordance with the previous investigation, we again obseved a lower number of prostate cancers in fathers of diabetic patients (OR 0.49; p = 0.0279).However, the application of the statistical method of Mantel-Haenszel showed no significant result concerning any of the cancer histories.
Fathers of patients suffering from type 2 diabetes were diagnosed less frequently with prostate cancer compared to fathers of non-diabetic controls. As first-degree relatives, e.g. diabetic patients and their fathers, share 50% of their genes, it appears plausible that genetic factors may play an important role in the negative association between diabetes and prostate cancer. However, different statistic analyses showed controversial results concerning the effect of type 2 diabetes on prostate cancers.
越来越多的证据表明，2型糖尿病患者患各种癌症的风险升高。然而，糖尿病可能是前列腺癌的一个保护因素，因为二者呈负相关。基于相同的遗传背景，糖尿病患者的父母在患癌风险方面可能表现出相似性。
我们开展了一项病例对照研究，确定了794例2型糖尿病病例和775例非糖尿病对照的家族史。随后，我们将研究扩大至801例2型糖尿病病例和1267例非糖尿病对照。
对于794例2型糖尿病患者和775例对照，我们观察到对照的母亲患子宫颈癌的比例升高（比值比（OR）0.19；95%置信区间（CI）0.02至0.88；p = 0.033）。糖尿病患者的母亲患肝癌和胆管癌（OR 5.23；95% CI 1.87至19.9；p = 0.0009）以及胃癌（OR 3.84；95% CI 1.47至12.4；p = 0.0049）的家族史增加。糖尿病患者的父亲患胰腺癌的比例升高（OR 4.92；95% CI 1.07至46.7；p = 0.039）。最值得注意的是，糖尿病患者的父亲患前列腺癌的比例较低（OR 0.47；95% CI 0.22至0.94；p = 0.032）。由于糖尿病患者比对照大14.3岁，预计糖尿病患者父母的癌症家族史水平会更高。因此，观察到的前列腺癌家族史较低水平可被视为高度可靠。对801例2型糖尿病患者和1267例对照的分析表明，对照的母亲患胃癌的比例升高（OR 2.67；p = 0.0106）。此外，糖尿病患者的父亲患胃癌的比例升高（OR 2.10；p = 0.0141）。与之前的调查一致，我们再次观察到糖尿病患者的父亲患前列腺癌的比例较低（OR 0.49；p = 0.0279）。然而，Mantel-Haenszel统计方法的应用在任何癌症家族史上均未显示出显著结果。
与非糖尿病对照的父亲相比，2型糖尿病患者的父亲被诊断出患前列腺癌的频率较低。作为一级亲属，例如糖尿病患者及其父亲，共享50%的基因，遗传因素可能在糖尿病与前列腺癌的负相关中起重要作用，这似乎是合理的。然而，不同的统计分析在2型糖尿病对前列腺癌的影响方面显示出有争议的结果。
