
Am J Cancer Res 2013;3(1):21-33
Review Article
Obesity-driven inflammation and cancer risk: role of myeloid derived 
suppressor cells and alternately activated macrophages
Derick Okwan-Duodu, Guillermo E Umpierrez, Otis W Brawley, Roberto Diaz
Department of Radiation Oncology, Medicine, Hematology and Medical Oncology, Emory University School of Medicine, Atlanta 
GA USA 30322
Received December 5, 2012; Accepted December 23, 2012; Epub January 18, 2013; Published January 25, 2013
Abstract: During carcinogenesis, tumors induce dysfunctional development of hematopoietic cells. Myeloid lineage cells, in the 
form of myeloid derived suppressor cells (MDSCs) and alternatively polarized M2 macrophages, influence almost all types of 
cancers by regulating diverse facets of immunosuppression, angiogenesis, cell proliferation, growth and metastasis. One-third 
of Americans are obese, and accumulating evidence suggests that obesity is a risk factor for various cancers. However, the 
relationship between these immune players and obesity are not well-described. In this review, we evaluate potential 
mechanisms through which different aspects of obesity, namely insulin resistance, increased estrogen, adiposity and low grade 
chronic inflammation from adipose tissue macrophages, may coalesce to promote MDSC induction and M2 macrophage 
polarization, thereby facilitating cancer development. Detailed understanding of the interplay between obesity and myeloid 
mediated immunosuppression may provide novel avenues for therapeutic targeting, with the goal to reduce the challenge 
obesity presents towards gains made in cancer outcomes. (ajcr0000164).
Keywords: Obesity, inflammation, myeloid derived suppressor cells, alternately activated macrophage, cancer
Address all correspondence to:
Dr. Roberto Diaz
Department of Radiation Oncology
Winship Cancer Institute
Emory University School of Medicine
Atlanta, GA 30322, USA.
Phone: (404) 7783473; Fax: (404) 7785520
E-mail: roberto.diaz@emory.edu
        
        
          
            
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        American Journal of Cancer Research