ALEXANDRIA, Va. — A new study published today in the Journal of Oncology Practice (JOP) reveals the findings of a 2018 American Society of Clinical Oncology (ASCO) Oncology Workforce survey on oncologists’ perceptions and practice behaviors related to diet, physical activity, and weight management in people with cancer — during and after active treatment. The research was also presented today at the American Institute for Cancer Research (AICR) 2019 Research Conference, Diet, Obesity, Physical Activity and Cancer — Beyond the Blueprint.

“Addressing obesity and weight management is a key component of cancer care — from prevention through survivorship. It is critical that we understand providers’ knowledge of the link between obesity and cancer, current practices, and where more support is needed,” said lead author and chair-elect of ASCO’s Cancer Prevention Committee, Jennifer A. Ligibel, MD. “This survey helps to identify the barriers oncologists face in providing weight management interventions for their patients, and will help guide future work by ASCO and others in the oncology field.”

Obesity, inactivity, and poor diet have been linked to risks and prognosis for several cancer types, including colon, breast, high-grade prostate, and uterine cancers. According to a recent analysis by the National Cancer Institute, if the current rates of obesity continue to trend upward, by 2030 there could be about 500,000 additional cases of cancer in the United States than would otherwise be expected.¹ Research also indicates that obesity and inactivity are linked to a higher risk of cancer recurrence and mortality in some cancers, especially breast, colon, and prostate cancers, and also may worsen several aspects of cancer survivorship, including quality of life and recovery from cancer treatment. In the absence of information regarding oncologists’ attention to these issues as a part of clinical care, ASCO sought to understand the perspective and behaviors of practicing oncologists through an online survey.

The survey of nearly 1,000 oncology providers revealed that their knowledge of the link between cancer and obesity — and their attention to weight management, physical activity, and diet in patients during and after cancer treatment — was high. However, that often did not result in patient referrals to weight management, physical activity, or diet programs, and the survey identified several barriers to providing weight management interventions to overweight and obese patients.

The vast majority of survey respondents agreed that there is strong evidence that being overweight or obese affects cancer treatment outcomes (93%) and that addressing a patient’s weight if they are overweight or obese should be a standard part of cancer treatment (89%). While 79% felt it was the responsibility of the treating physician to make recommendations related to nutrition and weight management, 83% also felt that clinicians needed more training to adequately address these issues in cancer patients, and 84% believed that weight, diet or physical activity interventions should be conducted by other clinical staff with relevant expertise.

The survey also found that during active treatment, most respondents assessed a patient’s body mass index (BMI) (72%) and physical activity level (78%) always or most of the time, but they were less likely to always or usually assess a patient’s diet (58%). The majority of respondents also reported that they always or most of the time advise patients to maintain a healthy weight or lose weight if overweight (67% during active treatment; 83% after treatment), increase physical activity levels (73% during active treatment; 83%; after treatment), and eat a healthy, balanced diet (77% during active treatment; 79% after treatment). 

However, few respondents referred patients for weight management interventions always or most of the time (24% during active treatment; 33% after treatment), and made referrals to a dietitian always or most of the time (43% during active treatment). Most respondents agreed that a lack of time for counseling or to set up a referral (66%), perceived patient resistance to behavioral interventions (73%), and lack of available resources for referrals to interventions (63%) were barriers to providing these interventions.

In recent years, ASCO has worked to address obesity in relation to cancer prevention efforts, as a potential factor in new cancer cases, and as a complicating aspect in care. In 2014, ASCO launched its Obesity Initiative, to raise awareness about the relationship between obesity and cancer, provide tools and resources to patients and providers, foster research in this area, and advocate for evidence-based weight management resources for survivors. Earlier this year, ASCO issued its first-ever set of Research Priorities to Accelerate Progress Against Cancer. Among the priorities, ASCO identified the reduction of obesity and its impact on cancer incidence and outcomes as a critical area on which to focus future research efforts. 

ASCO will focus on forging collaborations with groups within and outside of the oncology field to provide education for medical professionals, raise public awareness of the negative health consequences of obesity, and find effective strategies for weight loss to reduce the burden of cancer. The Cancer Prevention Committee’s Obesity and Energy Balance Subcommittee will use these findings to help focus educational programming along with other initiatives and resources that may support providers in assisting their patients to address weight management. 

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1. Sung, H. P., Siegel, R. L., Rosenberg, P. S., & Jemal, A. P. (2019, February 3). Emerging cancer trends among young adults in the USA: analysis of a population-based cancer registry. The Lancet Public Health, 4(3), pp. PE137-E147. doi: https://doi.org/10.1016/S2468-2667(18)30267-6