Gynecologic Oncology 126 (2012) 274–276
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Gynecologic Oncology
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Clinical Commentary
Obesity: Too big a problem to ignore
As the obesity pandemic rages globally, we, the Oncology commu-nity, need to join the front-line in the war against this deadly disease.In the past, obesity was seen as a social disease associated with phys-ical appearance and low self-esteem. No one foresaw obesity as aleading killer contributing to a multitude of physical ailments includ-ing cancer. Overweight and obesity are the fifth leading cause ofglobal deaths, accounting for at least 2.8 million adult deaths annually[1]. Between 7% and 41% of global cancers are attributable to over-weight and obesity with an estimated 1.4 million new cases of cancerin 2012. The “globesity” statistics are staggering and should catalyzeoncologists to join the fight against this deadly and preventabledisease.
In order to fight excess weight conditions we must be able tocorrectly identify patients who are overweight and obese. Primarycare providers often under diagnose obesity in adults and children[2]. Both the World Health Organization (WHO) and the NationalInstitutes of Health (NIH) have set clinical guidelines using bodymass index (BMI) with underweight (b18.5 kg/m2), normal weight(≥18.5 to b25.0 kg/m2), overweight (≥25.0 to b30.0 kg/m2), andobese (≥30.0 kg/m2) classifications [1]. In addition, obese states arecategorized as obese (obese I) (30–34.9), severely obese (obese II)(35–39.9), and morbidly obese (obese III) (BMI>40). BMI is a verysimple calculation and useful measure of overweight and obesity. It isimportant for oncologists to obtain a standard baseline BMI to betterunderstand the effect this factor may have on the risks of malignancyand mortality, and to assist in providing comprehensive counseling.
We experienced an incredible rise in obesity rates in the USstarting in the 1980s. Globally the pandemic has swept across bothdeveloped and developing countries (Fig. 1) [1]. The global escala-tion in weight is unprecedented in human history. The worldwideprevalence of obesity has more than doubled between 1980 and2008. Currently 1.6 billion individuals are obese worldwide—an esti-mated 205 million men and 297 million women [1]. More con-cerning is the alarming prevalence of childhood obesity. Since the1970s, the prevalence of obesity has more than doubled for childrenand nearly 43 million children under the age of five were overweightin 2010 [1,3]. The obesity pandemic if left unchecked will reach un-precedented proportions in 2050 with 165 million obese adults inthe US [4].
The rising prevalence of obesity will translate into an increasedrisk of diseases including cancer, disabilities, death, and health expen-ditures. Obesity and morbid obesity are associated with an increasedrate of death from all causes. Due to the obesity epidemic life expec-tancies in the US are projected to decline for the first time in a thou-sand years [5]! The increased risk of death associated with obesity isdue to metabolic complications that lead to a variety of diseases in-cluding cardiovascular disease, type 2 diabetes, and a variety of
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cancers including endometrial, ovarian, breast, colonic/rectal, kidney,esophageal, and pancreatic carcinomas [1]. Worldwide, 2.8 millionpeople die each year as a result of being overweight and obese andan estimated 35.8 million (2.3%) of global disability-adjusted lifeyears are caused by excess weight disorders [1].
The mechanisms by which obesity induces or promotes tumori-genesis vary by specific cancers, however they include insulin resis-tance, hyperinsulinemia, increased bioavailability of peptide andsteroid hormones, dysregulated adipokines, and obesity-inducedhypoxia. Alterations in endogenous hormone metabolism and inflam-mation may represent the critical link between malignancy risk andobesity. Not only does adiposity contribute to the increased incidenceof cancers, but also an increased risk of death from cancers of the en-dometrium, colon, breast, kidney, ovary, esophagus, stomach, pancre-as, gallbladder and liver [6].
There is conflicting data regarding BMI and clinical outcome in en-dometrial and ovarian cancer [7–9]. For example, recent publicationssuggest that BMI does not influence survival in women with endome-trial cancer [7,8]. Conversely, von Gruenigen et al. found that obesepatients with early endometrial cancer had higher mortality fromcauses other than endometrial cancer [9]. In addition, higher BMIhas been associated with lower quality of life (QoL) in endometrialcancer survivors [10]. Howell et al. performed a systematic reviewof cancer survivorship services and reported that interventions thatpromote healthy lifestyle behaviors appear to improve physical func-tioning, psychosocial well-being, and QoL [11]. Interventions thatpromoted exercise, diet, or both, with or without counseling, weregenerally effective at improving outcomes in overall physical health[11]. The “Survivors of Uterine Cancer Empowered by Exercise andHealthy Diet (SUCCEED)” trial evaluated nutrition, exercise, and be-havioral modification counseling from a physician, psychologist, reg-istered dietitian, and physical therapist in women with endometrialcancer. The results demonstrated that with a structured multi-disciplinary approach, overweight and obese endometrial cancer sur-vivors lose weight, increase physical activity, and improve theirnutrition quality (in press).
Because of the growing evidence incriminating obesity in a vari-ety of oncologic and non-oncologic diseases, we should transformour approach regarding the care of overweight and obese patients.As oncologists we are in a unique and pivotal position to join thewar against obesity. But what can be done? Tackling obesity com-prehensively will require an interdisciplinary approach includingthe patients' primary care providers and development of survivor-ship programs as well as societal changes and implementation ofpublic policies against obesity.
To combat obesity our options include counseling, preventivetherapies (for example prophylactic progestins ormetformin to prevent
Fig. 1. Estimated obesity (BMI>30 kg/m2) prevalence in women aged 15–100 years in 2010 [1].
275Clinical Commentary
endometrial cancer), and referral for bariatric surgery. Increased physi-cal activity and avoidance of sedentary behavior have been associatedwith significantly lower risk of select cancers [12]. Bariatric surgeryhas been reported to dramatically reduce the risk for developing certaintypes of cancers [13]. However, bariatric surgery was not associatedwith an overall decrease in standardized incidence ratios of obesity-related cancerswith increased time after the surgery [14]. Thus bariatricsurgery does not appear to completely reverse all the detrimental andcarcinogenic effects of obesity. These findings underscore the need forprevention and counseling.
Counseling combined with a comprehensive education programtargeting nutrition and exercise is the key to combating obesity. Animportant challenge is that patients are often unaware that theyare overweight or obese. Only 22.2% of obese women and 6.7% ofobese men correctly classified themselves as obese [15]. Thus, wecan counsel our patients about excessive weight conditions and self-recognition. Furthermore, overweight and obese patients frequentlyfeel stigmatized in healthcare settings. When obese patients feel stig-matized they are less motivated to adopt healthy lifestyle changesand are vulnerable to depression, low self-esteem, anxiety, and sui-cide [16]. Thus a compassionate and sensitive approach to counselingis required. Impediments to counseling are numerous including: time,reimbursement, fear of patient alienation, lack of training and re-sources. Continuing Medical Education centered on obesity-relatedissues is required to educate physicians on appropriate counselingtechniques and management of obesity.
Programs that provide intensive counseling with a focus on nu-trition, physical activity, and sedentary behavior are needed. TheCanadian Cancer Journey Survivorship Expert Panel made the fol-lowing recommendations for cancer survivors: (1) exercise, dietary,and smoking-cessation programs should be tailored to meet the in-dividual survivor's goals, ability level, and available resources; (2)advise cancer survivors to gradually increase physical activity inten-sity, as tolerated, for a minimum goal of 30 min of exercise daily,5 days per week, if possible. (3) Advise cancer survivors to integratea combination of aerobic exercises, strength training, flexibilitytraining; (4) refer cancer survivors to the Canadian Food Guide forhealthy diet recommendations and consider special needs related
to cancer diagnosis and treatment; and (5) consider referring can-cer survivors to a registered exercise professional and a registereddietician to facilitate adoption of healthy lifestyle management be-haviors, especially for issues such as weight maintenance, bodycomposition, and management of persistent fatigue [11]. However,oncologists can't do this alone. Multidisciplinary survivorship pro-grams are needed to provide the level of care required to achievea successful outcome.
As oncologists we have an amazing opportunity to counsel our pa-tients who suffer from excess weight conditions and improve and po-tentially save their lives. It is time for us to move from the defensiveposition to an offensive one in the war against obesity.
Conflict of interest statementNo conflict of interest.
References
[1] World Health Organization Website. Obesity and overweight Fact sheet N°311Updated March 2011. (http://www.who.int/mediacentre/factsheets/fs311/en/);Obesity: preventing and managing the global epidemic: Report of a WHO consul-tation on obesity. Geneva, Switzerland: World Health Organization; 1998. WHOTechnical Report Series 894; WHO Global Infobase. (https://apps.who.int/infobase/Comparisons.aspx); The WHO global strategy on diet, physical activityand health 2004. (http://www.who.int/dietphysicalactivity/en/). (http://www.who.int/nutrition/publications/obesity/WHO_TRS_894/en/index.html); Burden:mortality, morbidity, and risk factors. (http://www.who.int/nmh/publications/ncd_report_chapter1.pdf).
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276 Clinical Commentary
[8] El-Safardi S, Sauerbier A, Hackethal A, Münstedt K. Body weight changes afterthe diagnosis of endometrial cancer and their influences on disease-relatedprognosis. Arch Gynecol Obstet 2012 http://dx.doi.org/10.1007/s00404-012-2224-2227.
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[12] McTiernan A, Irwin M, Vongruenigen V. Weight, physical activity, diet and prog-nosis in breast and gynecologic cancers. J Clin Oncol 2010;28:4074–80.
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[14] Ostlund P, Lu Y, Lagergren J. Risk of obesity-related cancer after obesity surgery ina population-based cohort study. Ann Surg 2010;252:972–6.
[15] Truesdale KP, Stevens J. Do the obese know they are obese? N C Med J 2008;69:188–94.
[16] Puhl RM, Heuer CA. Weight bias: a review and update. Obesity 2009;17:941–64.
Angeles Alvarez SecordGynecologic Oncology, Duke University Medical Center,
Durham, NC, USACorresponding author at: Duke University Medical Center, Box 3079,
Durham, NC 27710, USA. Fax: +1 919 684 8719.E-mail address: [email protected]
Paola A. GehrigGynecologic Oncology, University of North Carolina at Chapel Hill,
Chapel Hill, NC, USA
19 February 2012
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