Title: Translation of the link between cancer and obesity to patients
Abstract: The report summarised in The Lancet (Oct 14, 2017, p 1716)1The Lancet The link between cancer and obesity.Lancet. 2017; 390: 1716Scopus (13) Google Scholar reinforces findings from previous studies that have noted an association between increased body-mass index and some malignancies.2Renehan 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: 569-578Summary Full Text Full Text PDF PubMed Scopus (3675) Google Scholar, 3Steele CB Thomas CC Henley SJ et al.Vital signs: trends in incidence of cancers associated with overweight and obesity—United States, 2005–2014.MMWR Morb Mortal Wkly Rep. 2017; 66: 1052-1058Crossref PubMed Scopus (207) Google Scholar Obesity is a major public health concern and the way in which the link is communicated to patients is paramount to solving this problem. Patients should be made aware that only an association has been observed—ie, increased body-mass index raises the likelihood of the development of some cancers. Several theories have been proposed to explain this link, implying that adipose tissue directly affects malignancy growth. Attribution of a single lifestyle factor, such as a high body-mass index, to cancer is difficult because individuals often indulge in multiple unhealthy habits. Are we able to say with confidence that weight loss in patients with obesity is associated with a reduced risk of developing cancer? The prospective, controlled, Swedish Obese Subjects study4Sjöström 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.Lancet Oncol. 2009; 10: 653-662Summary Full Text Full Text PDF PubMed Scopus (545) Google Scholar found that bariatric surgery was associated with a reduced incidence of cancer; however, no such association was found based on weight change. Juhua Luo and colleagues5Luo J Chlebowski RT Hendryx M et al.Intentional weight loss and endometrial cancer risk.J Clin Oncol. 2017; 35: 1189-1193Crossref PubMed Scopus (64) Google Scholar have shown that intentional weight loss is associated with reduced risk of endometrial cancer in postmenopausal women with obesity. Therefore, the association between cancer and weight change requires further investigation in a generalisable cohort. We declare no competing interests. The link between cancer and obesityThe US Centers for Disease Control and Prevention released a new report on cancer and obesity last week, highlighting that cancers associated with overweight and obesity, including thyroid, liver, kidney, and ovarian cancer, constitute 40% of cancers diagnosed in the USA, with over 630 000 diagnoses in 2014 alone. The study looked at data from the United States Cancer Statistics for 2005-2014. Disparities between sexes in the rates of cancers associated with obesity are especially stark, with 55% of all cancers diagnosed in women being associated with overweight and obesity, compared with only 24% of cancers in men. Full-Text PDF