Postoperative mortality in cancer patients with preexisting diabetes: systematic review and meta-analysis.

Diabetes appears to increase risk for some cancers, but the association between preexisting diabetes and postoperative mortality in cancer patients is less clear. Our objective was to systematically review postoperative mortality in cancer patients with and without preexisting diabetes and summarize results using meta-analysis. RSEARCH DESIGN AND METHODS: We searched the Medical Literature Analysis and Retrieval System Online (MEDLINE) and Excerpta Medica Database (EMBASE) for articles published on or before 1 July 2009, including references of qualifying articles. We included English language investigations of short-term postoperative mortality after initial cancer treatment. Titles, abstracts, and articles were reviewed by at least two independent readers. Study population and design, results, and quality components were abstracted with standard protocols by one reviewer and checked for accuracy by additional reviewers.