The link between obesity and cancer
Medical costs associated with obesity are estimated to range from $147 billion to nearly $210 billion per year. It's now common knowledge that obesity plays a significant role in contributing to several major illnesses — including cardiovascular disease and diabetes — in terms of both risk and mortality.
But did you know that obesity is also a major contributor to the nation's cancer toll and is quickly overtaking tobacco as the leading preventable cause of cancer?
As many as 84,000 cancer diagnoses each year are attributed to obesity, and being overweight or obese is implicated in 15 to 20 percent of total cancer-related mortalities, according to the 2014 American Society of Clinical Oncology position statement on obesity and cancer.
These facts take on increased urgency when you take into account the prevalence of obesity in the United States. Obesity rates have increased dramatically since 1990, with more than one-third of American adults (more than 72 million people) and 17 percent of American children and adolescents categorized as obese.
There is increasing evidence linking obesity to elevated risk of cancer, recurrence and cancer-related mortality in individuals diagnosed with early-stage disease:
- A recent meta-analysis of 82 studies, including more than 200,000 patients with breast cancer, demonstrated a 75 percent increase in mortality in premenopausal women and a 34 percent increase in mortality in postmenopausal women who were obese at the time of breast cancer diagnosis, as compared with patients who were of normal weight at diagnosis.
- Obese men seem to be at increased risk of developing biologically aggressive prostate cancers and also are more likely to have advanced disease at the time of prostate cancer diagnosis.
- Obesity can interfere with the effective delivery of systemic cancer therapy and can contribute to morbidity from treatment.
- Obesity is a risk factor for poor wound healing, postoperative infections and lymphedema, as well as for developing comorbid illness (such as heart disease, cerebrovascular disease and diabetes), in cancer survivors.
- Obesity also places individuals at increased risk of developing second primary malignancies.
Sadly, public awareness of the relationship between obesity and cancer risk remains limited, and definitive data from randomized trials demonstrating a beneficial impact of weight loss or other behavior change after cancer diagnosis are also currently lacking. Significant efforts are needed to educate the public regarding the links between obesity and cancer, and disseminate knowledge to help initiate and maintain healthy lifestyle changes to diminish the risk in developing cancers.
A cancer diagnosis may serve as a teachable moment, a term used by behavioral scientists to describe naturally occurring life transitions or health events that have the potential to motivate individuals to adopt risk-reducing or health-protective behaviors. Indeed, many cancer survivors report that they have attempted to make positive health behavior changes after a cancer diagnosis.
But don't wait for a cancer diagnosis — or other health crisis — to make changes to improve your health.Talk to your doctor about the steps you can take today to help prevent serious, potentially life-threatening, illness.
About The Author
Chris Chen, MD, MPH, is an oncologist at the MultiCare Regional Cancer Center in Tacoma. He specializes in Hematology, Oncology/Hematology (Cancer and Blood Disorders) and Medical Oncology. For more information, call 253-403-1677 or visit multicare.org/cancer.More stories by this author