The American Centre for Disease Control and Prevention (CDC) estimates that more than 50% of Americans are not aware that being overweight or obese can increase their risk of cancer. In the United Kingdom, Cancer Research United Kingdom (CRUK) have predicted that more than 1 in 20 cancer patients were either overweight or obese. GLOBOCAN project also predicted that the number of new cancer incidence increases with the number of patients who are overweight or obese.
What is more alarming is that being overweight has been linked to cancer with poor prognosis and this relationship was well-studied. Overweight or obese patients have 1.5 times higher risk to develop pancreatic cancer, about 2 times higher risk to develop kidney cancer or liver cancer, and 2-4 times higher risk to develop endometrial cancer.
“Obese people have higher levels of insulin and insulin-like growth factor that promotes cancer”
Recent studies suggest many possible reasons why people who are overweight or obese are more likely to develop cancer. One of the hypothesis is that obese people are constantly in the state of inflammation at low levels, which induces DNA damage. Chronic activation of Toll-like receptor, our first-line defence mechanism, are also found to induce cancer formation. Fat tissues constantly over produce hormones, such as oestrogen which may increase the risk of breast, endometrial and ovarian cancers. Similarly, obese people have higher levels of insulin and insulin-like growth factor that promotes cancer development. Yet another alternative hypothesis is that fat cells may produce adipokine (a hormone) that promote cell proliferation.
Therefore, it is important to keep your body weight within a healthy range and to reduce waist circumference. Many studies also conclude that less weight gain during adulthood contributes to lower risks of cancers [and for postmenopausal women—breast, endometrial, and ovarian cancers]. Take care of yourself before it is too late!
References:
- Arnold M, Pandeya N, Byrnes G, Renehan PAG, Stevens GA, Ezzati PM. Global burden of cancer attributable to high body-mass index in 2012: a population-based study. Lancet Oncol. 2015 January ; 16(1): 36–46.
- Genkinger JM, Spiegelman D, Anderson KE, Bernstein L, van den Brandt PA, Calle EE, et al. A pooled analysis of 14 cohort studies of anthropometric factors and pancreatic cancer risk. Int. J. Cancer, 2011; 129: 1708–1717.
- Wang F. and Xu Y. Body mass index and risk of renal cell cancer: A dose-response meta-analysis of published cohort studies. Int. J. Cancer, 2014; 135: 1673–1686.
- Chen Y, Wang X, Wang J, Yan Z, Luo J. Excess body weight and the risk of primary liver cancer: an updated meta-analysis of prospective studies. Eur J Cancer. 2012 Sep;48(14):2137-45
- Veronica Wendy Setiawan, Hannah P. Yang, Malcolm C. Pike, Susan E. McCann, Herbert Yu, Yong-Bing Xiang, et al. Type I and II Endometrial Cancers: Have They Different Risk Factors? Journal of Clinical Oncology 2013; 31 2607-2618.
- CW Mai, YB Kang, MR Pichika. Should a Toll-like receptor 4 (TLR-4) agonist or antagonist be designed to treat cancer? TLR-4: its expression and effects in the ten most common cancers. OncoTargets and therapy, 2013: 6, 1573
- Gallagher EJ, LeRoith D. Obesity and diabetes: The increased risk of cancer and cancer-related mortality. Physiological Reviews 2015; 95(3):727-748.
Image credit:
1. https://www.cancerresearchuk.org/sites/default/files/hero_image_obesity.jpg
2. https://cdn.images.express.co.uk/img/dynamic/11/590x/obese-man-808287.jpg
