title: Type 2 diabetes mellitus and colorectal cancer: meta-analysis on sex-specific differences.
abstract: Although there is consent concerning a higher risk for colorectal cancer (CRC) amongst patients with type 2 diabetes mellitus (T2DM), there remains uncertainty regarding potential sex differences in the strength of this association. We reviewed and summarised epidemiological studies assessing the sex-specific association of T2DM with the risk for CRC. All relevant studies published until 14th February 2011 were identified by a systematic search of MEDLINE, EMBASE, BIOSIS Previews and ISI Web of Knowledge databases and cross-referencing. We included observational studies that reported relative risk (RR) or odds ratio (OR) estimates with 95% confidence intervals (CIs) for the association between T2DM and CRC. Two authors independently extracted data and assessed study quality of each study in a standardised manner. Study-specific estimates were pooled for both sexes separately using random-effects models. A total of 29 eligible studies were used for meta-analysis. Overall estimates of relative risk (RR) were very similar amongst men (RR=1.29; 95%-confidence interval (CI): 1.19-1.140) and women (RR=1.34; 95%-CI: 1.22-1.47). In both men and women, risk estimates from case-control studies were slightly higher than those from cohort studies. Overall, T2DM is associated with a moderate increase in CRC risk in both men and women.
authors: Division of Clinical Epidemiology and Aging Research, German Cancer Research Center, Im Neuenheimer Feld 581, 69120 Heidelberg, Germany.
authors: Heike U
authors: HU
authors: Krämer
authors: Ben
authors: B
authors: Schöttker
authors: Elke
authors: E
authors: Raum
authors: Hermann
authors: H
authors: Brenner
mesh_terms: D016022:Case-Control Studies; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000209:etiology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D006801:Humans; D012737:Sex Factors