Obesity and cancer
The association between obesity, as defined by a body mass index of 30 or higher, and risk of a variety of types of cancer has received a considerable amount of attention in recent years.[1] Obesity has been associated with an increased risk of esophageal cancer, pancreatic cancer, colorectal cancer, breast cancer (among postmenopausal women), endometrial cancer, kidney cancer, thyroid cancer, and gallbladder cancer.[2] Obesity may also lead to increased cancer-related mortality.[1]
Mechanisms
The mechanisms by which obesity may increase the risk of cancer are not well understood,[1] but it is believed that the combined effects of the adipose tissue environment and the endocrine alterations that accompany it among obese people both interact to promote tumor initiation and progression.[3] Adipose tissue also creates an inflammatory environment that enhances the ability of tumor cells to metastatize.[4]
Association by cancer site
Bladder cancer
Obesity is associated with an increased risk of bladder cancer.[5]
Breast cancer
Obesity has been found to decrease the risk of breast cancer among African and Caucasian women, but increase it among Asian women.[6] Obesity is also associated with decreased survival among women with breast cancer, regardless of whether the cancer is pre- or post-menopausal.[7]
Colorectal cancer
Both general and central obesity are associated with an increased risk of colorectal cancer (CRC). The relative risk among obese people relative to those of normal weight has been reported to be 1.334.[8] An association between increased BMI and risk of colorectal adenoma has been reported, as has a dose-response relationship between BMI and colorectal adenoma risk.[9][10] Increased BMI also increases all-cause mortality and mortality from CRC specifically among people diagnosed with CRC.[11]
Lung cancer
Obesity has been found to protect against lung cancer, especially among those who smoke or have smoked cigarettes.[12]
Renal cell cancer
Obesity is a risk factor for renal cell cancer.[13]
Thyroid cancer
Obese people are at a higher risk of thyroid cancer than are their normal weight counterparts.[14]
References
- 1 2 3 Vucenik, I; Stains, JP (October 2012). "Obesity and cancer risk: evidence, mechanisms, and recommendations.". Annals of the New York Academy of Sciences 1271: 37–43. doi:10.1111/j.1749-6632.2012.06750.x. PMID 23050962.
- ↑ "Obesity and Cancer Risk". National Cancer Institute. Retrieved 28 August 2015.
- ↑ Park, J; Morley, TS; Kim, M; Clegg, DJ; Scherer, PE (August 2014). "Obesity and cancer--mechanisms underlying tumour progression and recurrence.". Nature Reviews Endocrinology 10 (8): 455–65. doi:10.1038/nrendo.2014.94. PMID 24935119.
- ↑ Gilbert, Candace A.; Slingerland, Joyce M. (14 January 2013). "Cytokines, Obesity, and Cancer: New Insights on Mechanisms Linking Obesity to Cancer Risk and Progression". Annual Review of Medicine 64 (1): 45–57. doi:10.1146/annurev-med-121211-091527.
- ↑ Sun, JW; Zhao, LG; Yang, Y; Ma, X; Wang, YY; Xiang, YB (2015). "Obesity and risk of bladder cancer: a dose-response meta-analysis of 15 cohort studies.". PloS one 10 (3): e0119313. PMID 25803438.
- ↑ Amadou, A; Ferrari, P; Muwonge, R; Moskal, A; Biessy, C; Romieu, I; Hainaut, P (August 2013). "Overweight, obesity and risk of premenopausal breast cancer according to ethnicity: a systematic review and dose-response meta-analysis.". Obesity reviews : an official journal of the International Association for the Study of Obesity 14 (8): 665–78. PMID 23615120.
- ↑ Chan, DS; Vieira, AR; Aune, D; Bandera, EV; Greenwood, DC; McTiernan, A; Navarro Rosenblatt, D; Thune, I; Vieira, R; Norat, T (October 2014). "Body mass index and survival in women with breast cancer-systematic literature review and meta-analysis of 82 follow-up studies.". Annals of oncology : official journal of the European Society for Medical Oncology / ESMO 25 (10): 1901–14. PMID 24769692.
- ↑ Ma, Y; Yang, Y; Wang, F; Zhang, P; Shi, C; Zou, Y; Qin, H (2013). "Obesity and risk of colorectal cancer: a systematic review of prospective studies.". PLoS One 8 (1): e53916. PMID 23349764.
- ↑ Okabayashi, K; Ashrafian, H; Hasegawa, H; Yoo, JH; Patel, VM; Harling, L; Rowland, SP; Ali, M; Kitagawa, Y; Darzi, A; Athanasiou, T (August 2012). "Body mass index category as a risk factor for colorectal adenomas: a systematic review and meta-analysis.". The American journal of gastroenterology 107 (8): 1175–85; quiz 1186. doi:10.1038/ajg.2012.180. PMID 22733302.
- ↑ Hong, S; Cai, Q; Chen, D; Zhu, W; Huang, W; Li, Z (November 2012). "Abdominal obesity and the risk of colorectal adenoma: a meta-analysis of observational studies.". European journal of cancer prevention : the official journal of the European Cancer Prevention Organisation (ECP) 21 (6): 523–31. PMID 22343656.
- ↑ Lee, J; Meyerhardt, JA; Giovannucci, E; Jeon, JY (2015). "Association between body mass index and prognosis of colorectal cancer: a meta-analysis of prospective cohort studies.". PloS One 10 (3): e0120706. doi:10.1371/journal.pone.0120706. PMID 25811460.
- ↑ Yang, Y; Dong, J; Sun, K; Zhao, L; Zhao, F; Wang, L; Jiao, Y (1 March 2013). "Obesity and incidence of lung cancer: a meta-analysis.". International journal of cancer. Journal international du cancer 132 (5): 1162–9. PMID 22777722.
- ↑ Wang, F; Xu, Y (1 October 2014). "Body mass index and risk of renal cell cancer: a dose-response meta-analysis of published cohort studies.". International journal of cancer. Journal international du cancer 135 (7): 1673–86. doi:10.1002/ijc.28813. PMID 24615287.
- ↑ Schmid, D; Ricci, C; Behrens, G; Leitzmann, MF (December 2015). "Adiposity and risk of thyroid cancer: a systematic review and meta-analysis.". Obesity reviews : an official journal of the International Association for the Study of Obesity 16 (12): 1042–54. doi:10.1111/obr.12321. PMID 26365757.