Obesity and Cancer Risk: Recent Review and Evidence
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The prevalence of overweight and obesity is increasing worldwide, and the evidence base for a link between obesity and cancer is growing. In the United States, approximately 85,000 new cancer cases per year are related to obesity. Recent research has found that as the body mass index increases by 5 kg/m2, cancer mortality increases by 10%. Additionally, studies of patients who have had bariatric surgery for weight loss report reductions in cancer incidence and mortality, particularly for women. The goal of this review is to provide an update of recent research, with a focus on epidemiologic studies on the link between obesity and cancer. In addition, we will briefly review hypothesized mechanisms underlying the relationship between obesity and cancer. High priorities for future research involve additional work on the underlying mechanisms, and trials to examine the effect of lifestyle behavior change and weight loss interventions on cancer and intermediate biomarkers.
KeywordsNeoplasm Obesity Overweight Cancer risk Intervention Review Insulin Insulin-like growth factors Sex steroid hormones Adipokines Hypoxia Oxidative stress
Maria Chang, a doctoral student, is supported in part by a cancer prevention fellowship that is supported by the National Cancer Institute grant R25E CA56452, Shine Chang, Principal Investigator.
No potential conflicts of interest relevant to this article were reported.
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
- 4.Vainio H, Bianchini F (Eds.): IARC Handbooks of Cancer Prevent--Weight Control and Physical Activity. Lyon, France: IARC Press; 2002.Google Scholar
- 5.World Cancer Research Fund/American Institute for Cancer Research: Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective. Washington DC: AICR; 2007.Google Scholar
- 7.•• Renehan AG, Tyson M, Egger M, Heller RF, Zwahlen M: Body-mass index and incidence of cancer: a systematic review and meta-analysis of prospective observational studies. Lancet 2008, 371:569-578. This is a meta-analysis of 221 datasets (282,137 incident cases) from prospective observational studies that extended beyond the 2007 WCRF findings. As BMI increased by 5 kg/m 2 , strong associations for esophageal carcinoma (RR = 1.52 for men, 1.51 for women) and renal cancer (RR = 1.33 for men, 1.34 for women) in both men and women were observed. Weak, but positive associations were found for leukemia, multiple myeloma, and non-Hodgkin’s lymphoma in both men and women.Google Scholar
- 10.• Prospective Studies Collaboration: Body-mass index and cause-specific mortality in 900 000 adults: collaborative analyses of 57 Prospective studies. Lancet 2009, 373:1083-1096. These are updated results on mortality and increased BMI, which include cancer mortality. The data came from 57 prospective studies, which includes approximately 900,000 adults. As BMI increased by 5 kg/m 2 , it was associated with a ~ 30% increase of all-cause mortality (HR = 1.29, 95% CI = 1.27–1.32). Specifically for cancer, all-cancer mortality indicated a 10% increase (HR = 1.10, 95% CI = 1.06–1.15) as BMI increases by 5 kg/m 2.Google Scholar
- 11.Picot J, Jones J, Colquitt JL, et al.: The clinical effectiveness and cost-effectiveness of bariatric (weight loss) surgery for obesity: a systematic review and economic evaluation. Health Technol Assess 2009, 13:1-190, 215-357, iii-iv.Google Scholar
- 12.•• Sjöström L, Gummesson A, Sjöström CD, et al.: Effects of bariatric surgery on cancer incidence in obese patients in Sweden (Swedish Obese Subjects Study): a prospective, controlled intervention trial. The Lancet Oncology 2009, 10:653-662. This is a prospective Swedish study of cancer incidence in 2010 obese patients who underwent bariatric surgery compared to 2037 matched obese controls who received conventional weight loss treatment. During the ~ 11-year average follow-up, 117 surgery patients and 169 controls developed a new cancer (HR = 0.67, 95% CI = 0.53–0.85, P = 0.0009).Google Scholar
- 13.• Adams TD, Stroup AM, Gress RE, et al.: Cancer incidence and mortality after gastric bypass surgery. Obesity (Silver Spring) 2009, 17:796-802. This is a study of cancer incidence and mortality in 6596 patients who had gastric bypass surgery compared to 9442 severely obese controls from the state’s driver’s license records. With an average follow-up time of 12.45 years, the surgery group had a lower incidence of regional or distant-stage cancer, and lower cancer mortality than controls.Google Scholar
- 16.Kawai M, Minami Y, Kuriyama S, et al.: Adiposity, adult weight change and breast cancer risk in postmenopausal Japanese women: the Miyagi Cohort Study. Br J Cancer 2010.Google Scholar
- 17.U.S. Department of Health and Human Services NIoH, National Heart, Lung, and Blood Institute and National Institute of Diabetes and Digestive and Kidney Diseases: Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: The Evidence Report (NIH Publication No. 98-4083); 1998:262.Google Scholar
- 21.• Roberts DL, Dive C, Renehan AG: Biological mechanisms linking obesity and cancer risk: new perspectives. Annu Rev Med 2010, 61:301-316. This provides a review on well-studied biological mechanisms for obesity and cancer, and provides additional hypotheses and possible mechanisms that may need to be further examined.Google Scholar
- 22.•• Nock NL, Berger NA: Obesity and Cancer: Overview of Mechanisms. In Cancer and Energy Balance, Epidemiology and Overview. Edited by Berger NA. New York: Springer; 2010: 129-179. This provides a comprehensive summary of all plausible biological mechanisms that explained the positive association between obesity and various cancers.Google Scholar
- 28.Gu F, Schumacher FR, Canzian F, et al.: Eighteen Insulin-like Growth Factor (IGF) pathway genes, circulating levels of IGF-1 and its binding protein (IGFBP-3), and risk of prostate and breast cancer. Cancer Epidemiol Biomarkers Prev 2010, In Press, Uncorrected Proof. Epub 2010 Sept 03.Google Scholar
- 36.Reuter S, Gupta SC, Chaturvedi MM, Aggarwal BB: Oxidative stress, inflammation, and cancer: How are they linked? Free Radical Biology and Medicine 2010, In Press, Uncorrected Proof. Epub 2010 Sept 06.Google Scholar