Expert discusses ASCO's policy statement on obesity–cancer link
Nearly 500,000 Americans are projected to be diagnosed with obesity-associated cancers annually by 2030, according to an ASCO press release.
As previously reported in HemOnc Today, ASCO published a position statement outlining the society’s commitment to reducing the effect of obesity on cancer and establishing a multipronged initiative to accomplish this goal.
The position statement includes recommendations regarding improvements in education and awareness about associations between obesity and cancer, access to new physician tools and resources, increased research efforts and updates to policies aimed at increasing access to obesity screening, diagnosis and treatment.
HemOnc Today spoke with the lead author of the policy statement about ASCO’s vision for the statement and how the cancer–obesity connection remains at the forefront of advocacy efforts.
Jennifer A. Ligibel, MD
Harvard Medical School
Dana-Farber Cancer Institute
What do you expect to accomplish with the ASCO statement?
The goal of the statement was to increase awareness of the ASCO Obesity Initiative and to describe ASCO’s ongoing and future efforts in this area. The policy statement describes the primary goals of the ASCO initiative, namely, to increase awareness of the relationship between obesity and cancer, to describe the ASCO Weight Management Toolkit released last summer, to discuss the importance of fostering high-quality research studying the effects of weight management on cancer risk and outcomes, and to describe the need for policy changes to ensure that cancer patients have access to weight management services, as the evidence supporting these programs evolves.
Do you think this will make a difference?
The ASCO policy statement is an important first step in calling attention to this issue. This statement in itself will not reduce rates of obesity. There are clearly deep-rooted societal issues underlying the rapid increase in rates of obesity in the United States and beyond over the past few decades. However, affecting real change will take the coordinated actions of many groups, and oncologists in general have not been active in this area to date. We see this statement as a first step in getting the oncology community involved in weight management programs, in fostering research and thinking about ways to help to make sure that these types of services are available for their patients. So, this is an important first step to lay out the actions of ASCO in this realm.
What challenges do you face when beginning to care for patients who are overweight or obese?
Although this policy statement did not focus on clinical care of obese patients, there have been a number of different efforts that ASCO and other organizations have developed over the past few years that have addressed this topic. For example, ASCO published a guideline in 2012 that focused on treatment considerations for obese patients. The primary message was that patients who are obese should receive chemotherapy treatments based on their actual body weight. There have been many reports that have demonstrated that using other methods to determine chemotherapy dosing for obese patients, such as using ideal body weight or capping total chemotherapy doses at a lower level than would be indicated by their full body weight, leads to poor outcomes in obese individuals.
Obesity is also associated with higher rates of complications from some cancer treatments, such as higher rates of surgical complications and toxicities from radiation. Obese individuals are also at higher risk of developing comorbidities such as heart disease or diabetes after cancer diagnosis, and are also at greater risk of second malignancies.
Do you make it a priority to tell patients they need to change their lifestyle to maximize their chances for successful outcomes? What percentage of patients actually do this?
First, a lot of the data that we have linking cancer and obesity come from observational studies, so it is important to recognize that there are still data that we need to tell patients definitively that if they lose a certain amount of pounds that it will have this type of an effect on their outcomes. I am always careful that I don’t overextend what is actually known. I do, however, talk to my patients about the importance of a healthy lifestyle, and I emphasize the importance of physical activity throughout the entire cancer trajectory. Yet, telling patients these things alone does not change behavior. People need a lot of support to do this, and this is one reason why it is important to foster a research agenda. We need to know whether weight loss and increased physical activity improve outcomes in cancer and we need to know how can we reliably help people to make these types of changes. Finally, if studies do demonstrate that making lifestyle changes after cancer diagnosis improves outcome, then we need to find ways to disseminate these programs to large groups of cancer survivors, and we need to advocate for third-party payment for these services.
How should this be addressed in survivorship care plans?
Many survivorship care plans, in addition to containing a synopsis of the cancer treatment that patients receive, are seeking to provide healthy lifestyle tips and other cancer screening tips. These types of suggestions should be a part of health maintenance for cancer survivors. The American Cancer Society for many years has put forward nutrition and physical activity guidelines for both cancer prevention and, more recently, for cancer survivors. The National Comprehensive Cancer Network also has healthy lifestyle guidelines for cancer survivors. Recommendations from these types of guidelines should be incorporated into cancer survivorship care plans. – by Jennifer Southall
For more information: Jennifer A. Ligibel, MD, can be reached at Dana-Farber Cancer Institute, 450 Brookline Ave., Boston, MA 02215.