An ASCO expert panel conducted a comprehensive literature assessment to determine how diet, weight, and exercise play a role in defining patient outcomes.
Patients actively receiving cancer treatment are encouraged to engage in aerobic and resistance exercises to alleviate treatment-related toxicities and improve quality of life, according to a new guideline published by ASCO.1
The updated guideline follows a literature analysis of 52 systematic reviews on the topics of exercise, died, and weight management, and results of 23 randomized clinical trials. Each of the selections underscored the value that exercise interventions may interpose on patients receiving either systemic therapy, radiation, or surgery.
Of note, this guideline represents the first of its kind to specifically focus on patients who are actively receiving treatment. It is intended for oncology professionals and designed to provide evidence-based recommendations for optimized treatment tolerance, quality of life, and cancer control outcomes.
Recommendation No. 1: Aerobic and Resistance Exercises
Oncology providers should encourage patients on active treatment to incorporate aerobic and resistance exercises to mitigate treatment-related adverse events (AEs).
Aerobic and resistance exercises have the potential to reduce fatigue, preserve cardiorespiratory fitness, physical functioning, and strength. In some populations, the benefits reach further; they may maintain or improve quality of life as well as help reduce anxiety and depression. Moreover, these interventions have a low risk of AEs.
It is important to note that although ASCO labeled this as a strong recommendation in the outline, the evidence quality is still moderate to low, and the benefits are not intended to extend to overall treatment outcomes or completion rates but instead are centered on improving life quality throughout treatment.
The authors of the guideline noted that prehabilitation is an emerging field but that oncology providers may consider encouraging patients about to undergo lung surgery to initiate preoperative exercises. This intervention is intended to reduce length of hospital stay and postoperative complications and had the strongest evidence compared with other tumor types included in the analysis.
As with the first part of this recommendation, the evidence has shown that the benefit of exercise outweighs the risks in this setting; however, the recommendation strength was listed as “weak” by ASCO because evidence quality was low and randomized control trials are warranted.
Recommendation No. 2: Dietary Patterns
According to the study authors, there is insufficient evidence to either recommend or condone specific diets such as ketogenic, low-carbohydrate, or low-fat diets. Similarly, functional foods and fasting have not been sufficiently linked to improved outcomes in quality of life, treatment toxicity, or disease control.
That said, neutropenic diets are not recommended. These diets specifically exclude raw fruits and vegetables, and they have not been shown to prevent infection in patients undergoing active treatment. This recommendation is evidence based and the authors note that the harms are likely to outweigh the benefits. However, according to ASCO, the evidence quality is low.
Recommendation No. 3: Weight Loss and Weight Gain
The expert panel strongly feels that there should be more research centered in this domain.
There is insufficient evidence tying intentional weight loss or weight gain interventions to quality of life, treatment toxicity, or cancer control outcomes. Despite this, the ASCO expert panel expressed that these are critical areas that provide health benefits to the general population, and therefore may also provide important benefits to patients with cancer.
Despite the lack of guidance underscored in the outline, authors note that dietary change and weight management strategies may still be valuable during or after cancer treatment. Further, a recent ASCO survey of over 2419 patients throughout the United States found that nearly 75% of patients make changes in their diet or exercise patterns following diagnosis.
In addition, the guideline stated that a lack of guidance does not equate to support of a diet filled with red meats and processed foods or carbohydrates; providers are still encouraged to discuss healthy diet and weight with their patients, but no specific recommendations are endorsed by the 2022 ASCO guideline.
According to the panel, there are numerous areas where research can be expanded to provide more concise consul to oncology professionals.
One such area is for individuals with advanced cancer. These individuals are often excluded from these trials because of concerns regarding the safety of such interventions‚ especially in patients with bone metastases. The guideline experts looked at a literature review which assessed 17 studies looking at patients with bone metastases. Although results were largely mixed, the findings suggested that there may be exercise benefit for these patients.
Moreover, the experts encourage investigators to consider incorporating diet, exercise, and weight assessments into routine clinical research. According to the authors, this guideline highlighted a profound gap in quality research in this area, yet “many opportunities exist at modest overall cost, to integrate validated and novel assessment tools of diet, nutritional status, and exercise into clinical trials, such as body composition assessment including fat distribution and lean muscle mass, use of enhanced statistical tools to analyze dietary patterns, use of wearables to capture physical activity, and validated fitness tests such as the [6-minute walking test] 6MWT.”
Moving forward, phase 1, 2, and 3 findings assessing diet, exercise, and weight management interventions will be needed across the care continuum to define the standards of care in this field.
Ligibel JA, Bohlke K, May AM, et al. Exercise, diet, and weight management during cancer treatment: ASCO guideline. J Clin Oncol. 2022;40(22):2491-2507. doi:10.1200/JCO.22.00687