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World J Diabetes. Jun 15, 2014; 5(3): 372-380
Published online Jun 15, 2014. doi: 10.4239/wjd.v5.i3.372
Diabetes and cancer: Associations, mechanisms, and implications for medical practice
Chun-Xiao Xu, Hong-Hong Zhu, Yi-Min Zhu
Chun-Xiao Xu, Department of Chronic Non-Communicable Diseases Control and Prevention, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang Province, China
Hong-Hong Zhu, Department of Public Health, College of Health and Human Services, Western Kentucky University, Bowling Green, KY 42101, United States
Yi-Min Zhu, Department of Epidemiology and Biostatistics, School of Public Health, Zhejiang University, Hangzhou 310058, Zhejiang Province, China
Author contributions: Xu CX conceived and drafted the manuscript; Zhu HH reviewed and revised the manuscript; Zhu YM conceived, supervised, revised and finalized the manuscript.
Supported by Zhejiang Provincial Program for the Cultivation of High-level Innovative Health Talents; Program for Zhejiang Leading Team of Science and Technology Innovation; Fundamental Research Funds for the Central Universities
Correspondence to: Yi-Min Zhu, MD, PhD, Department of Epidemiology and Biostatistics, School of Public Health, Zhejiang University, No. 388, Yuhangtang Road, Hangzhou 310058, Zhejiang Province, China. zhuym@zju.edu.cn
Telephone: +86-571-88208138 Fax: +86-571-88208198
Received: November 28, 2013
Revised: February 7, 2014
Accepted: April 17, 2014
Published online: June 15, 2014
Processing time: 199 Days and 17.6 Hours
Abstract

Both diabetes mellitus and cancer are prevalent diseases worldwide. It is evident that there is a substantial increase in cancer incidence in diabetic patients. Epidemiologic studies have indicated that diabetic patients are at significantly higher risk of common cancers including pancreatic, liver, breast, colorectal, urinary tract, gastric and female reproductive cancers. Mortality due to cancer is moderately increased among patients with diabetes compared with those without. There is increasing evidence that some cancers are associated with diabetes, but the underlying mechanisms of this potential association have not been fully elucidated. Insulin is a potent growth factor that promotes cell proliferation and carcinogenesis directly and/or through insulin-like growth factor 1 (IGF-1). Hyperinsulinemia leads to an increase in the bioactivity of IGF-1 by inhibiting IGF binding protein-1. Hyperglycemia serves as a subordinate plausible explanation of carcinogenesis. High glucose may exert direct and indirect effects upon cancer cells to promote proliferation. Also chronic inflammation is considered as a hallmark of carcinogenesis. The multiple drugs involved in the treatment of diabetes seem to modify the risk of cancer. Screening to detect cancer at an early stage and appropriate treatment of diabetic patients with cancer are important to improve their prognosis. This paper summarizes the associations between diabetes and common cancers, interprets possible mechanisms involved, and addresses implications for medical practice.

Keywords: Diabetes mellitus; Cancer; Association; Mechanism; Medical practice

Core tip: The diabetes-cancer link is summarized and discussed in detail and it may potentially be attributed to hormonal disorders, chronic inflammation and metabolic alterations. Besides, implications for medical practice are also addressed.