By Ellen Feldman, MD
Altru Health System, Grand Forks, ND
Dr. Feldman reports no financial relationships relevant to this field of study.
• In 2010, the American College of Sports Medicine published the first set of exercise guidelines for cancer survivors. It concluded that exercise could be helpful in improving physical fitness after cancer, but that more studies were necessary to provide specific recommendations.
• The updated 2018 guidelines result from more than 2,500 randomized controlled trials and represent a 281% increase of published studies regarding exercise in cancer survivors between 2010 and 2018.
• There is strong evidence that anxiety, depression, fatigue, health-related quality of life, and physical functioning are improved with specific doses of aerobic exercise, resistance training, or a combination of the two.
• There is moderate evidence that bone health and sleep may be improved with specific exercise, but there is insufficient evidence regarding cardiotoxicity, chemotherapy-induced peripheral neuropathy, cognitive function, falls, nausea, pain, sexual functioning, and treatment tolerance.
SYNOPSIS: The 2018 guidelines for exercise in cancer survivors conclude there is sufficient evidence to recommend specific doses of aerobic exercise, resistance training, and/or a combination of the two to improve common symptoms found in this population, such as anxiety, depression, fatigue, and quality of life.
SOURCE: Campbell KL, Winters-Stone K, Wiskemann J, et al. Exercise guidelines for cancer survivors: Consensus statement from international multidisciplinary roundtable. Med Sci Sports Exerc 2019;51:2375-2390.
Advances in cancer treatment, prevention, and early detection have been instrumental in dropping U.S. cancer deaths by a remarkable 29% from 1991 to 2017.
As the population of cancer survivors increases (16.9 million in the United States and growing), health concerns related to the sequelae of cancer and the aftermath of cancer treatment have become a focus of research.1-2
The importance of exercise in improving health outcomes both during and after cancer treatment is a relatively new concept in the medical world. Up until the early 2000s, advice to cancer patients and survivors was to rest as much as possible and maintain a sedate lifestyle.3
The 1990s ushered in a new era of research into the health benefits of exercise. Drawing on the results of preliminary studies looking at health benefits from exercise during and after cancer treatment, the American College of Sports Medicine (ACSM) published the first set of exercise guidelines for cancer survivors in 2010. These guidelines noted the paucity of specific studies for cancer patients in this field but unequivocally stated that evidence was sufficient to recommend survivors “avoid inactivity” and follow the 2008 Physical Activity Guidelines for adults with chronic conditions.4
Recognizing the need for studies specific to cancer patients, the years from 2010 to 2018 saw an explosion in randomized, controlled trials (RCTs) regarding cancer and exercise. The 2018 ACSM International Multidisciplinary Roundtable on Physical Activity and Cancer Prevention and Control considered results from more than 2,500 RCTs to generate recommendations and guidelines for exercise during and after cancer treatment. Notably, this group decided to focus on studies involving aerobic exercise and/or resistance training. Other types of exercise, such as yoga, high-intensity interval training, and specific recreational sports, are mentioned as needing more research and investigation.
One of the goals of these updated ACSM guidelines is to generate evidence-based prescriptions for exercise frequency, intensity, and time (FITT) for treatment of specific health outcomes in cancer survivors. A FITT prescription is offered only when there are sufficient quantity and quality of evidence. Another goal is to note safety measures and considerations specifically for cancer survivors. Campbell et al note that clinicians should be aware that in each health outcome category, evidence usually was derived from studies looking at limited types of cancer (often breast or prostate), but outcomes are assumed to be relevant to all cancer survivors unless otherwise specified.
Another important limitation of these guidelines is that because the RCTs usually did not target survivors with the most severe symptoms, the FITT prescriptions and recommendations may not be appropriate for all survivors — especially those in this category. Overall recommendations for improvement in health-related outcomes in cancer survivors include moderate-intensity aerobic training at least three times weekly for at least 30 minutes over eight to 12 weeks or combined aerobic and resistance training at least twice weekly with at least two sets of eight to 15 repetitions. In general, supervised exercise programs appear more effective than home-based or self-designed programs.
The guidelines include specific recommendations according to health outcome. Strong evidence and a FITT prescription are provided for anxiety, depressive symptoms, fatigue, health-related quality of life, lymphedema, and physical function. Note that for the lymphoma studies, evidence is from studies in upper extremity lymphedema in breast cancer survivors and may not generalize for other cancers.
Table 1 shows health conditions with strong evidence for a role of exercise in reducing symptoms for cancer survivors. Where available, the chart displays information regarding:
- FITT prescription modality (aerobic, resistance, or combined) and intensity
- FITT prescription time recommendations
- further information about modality
- need for supervision of exercise (such as from a trainer or physical therapist vs. at home)
- evidence for a dose relationship between exercise intensity and symptom reduction dose relationship.
Table 1. Health Conditions with Strong Evidence Supporting a Role for Exercise in Symptom Reduction in Cancer Survivors
|
|
FITT Modality and Intensity
|
FITT Time
|
Notes
on Modality
|
Supervised?
|
Dose Relationships
for Efficacy
|
|
Anxiety
|
Moderate-intensity aerobic training or combined
|
30 minutes, 3/week for 12 weeks or aerobic and resistance combined for 6-12 weeks
|
Resistance training alone does not lead to improvements in anxiety
|
More efficacy in supervised exercise programs
|
Dose relationship between intensity of exercise and reduction of symptom unclear
|
|
Depressive Symptoms
|
Moderate-intensity aerobic exercise or combined
|
30 minutes, 3/week for 12 weeks or combined aerobic and resistance training 2/week for 6-12 weeks
|
Resistance training alone does not lead to improvements in depressive symptoms
|
More efficacy in supervised exercise programs
|
Dose response relationship with 180 minutes/week of exercise associated with more symptom relief than 90 minutes/week
|
|
Fatigue
|
Moderate-intensity aerobic training or combined
|
30 minutes, aerobic 3/week for at least 12 weeks or combined moderate-intensity aerobic and resistance training 2/week for 12 weeks
|
Resistance training alone not evaluated
|
Efficacy similar in unsupervised and supervised programs
|
Impact of exercise was strongest for moderate- to vigorous-intensity exercise, 30 minutes or longer/ up to 150 minutes/week
|
|
Health-related QOL
|
Combined aerobic and resistance training
|
30 minutes, 2-3/week for 12 weeks
|
No further information
|
Efficacy greater in supervised exercise programs
|
No further information
|
|
Lymphedema
|
Resistance training focused on large muscle groups and supervised by an exercise professional (for safety)
|
30 minutes, 2-3/week
|
Insufficient evidence for aerobic alone
|
Efficacy and safety greater in supervised exercise programs
|
No further information
|
|
Physical Function
|
Moderate-intensity aerobic and/or resistance training
|
30 minutes, 3/week for 8-12 weeks
|
Aerobic, resistance, or combination effective
|
Efficacy greater in supervised exercise programs, but for older survivors, more intense, unsupervised programs may be as effective
|
No further information
|
|
FITT: Frequency, intensity, time, and type
QOL: Quality of life
|
Moderate evidence exists for a role of exercise in bone health and sleep. There is not enough evidence to generate a FITT prescription.
In cancer survivors with bone fragility as the result of osteoporosis or metastases, joint issues, and/or balance problems, safety considerations may contraindicate high-impact training programs used to improve bone health. Table 2 displays the two health conditions for which there is moderate evidence for a role of exercise in symptom reduction, and further information regarding modality of exercise, intensity, time, and evidence for a need for supervision of the exercise program to obtain efficacy.
Table 2. Health Conditions for Which There is Moderate Evidence for a Role of Exercise in Symptom Reduction
|
| |
Modality and Intensity
|
Time
|
Supervised?
|
Bone Health
|
Combined moderate-vigorous intensity aerobic with high-impact training
|
1 year
|
More evidence for supervised programs
|
Sleep
|
Moderate-intensity aerobic exercise (particularly walking)
|
3/week for 12 weeks or combined aerobic and resistance training 2/week for 6-12 weeks
|
Not enough information
|
There is insufficient evidence for exercise efficacy in addressing cardiotoxicity, peripheral neuropathy, cognitive functioning, falls, nausea, pain, sexual function, and treatment tolerance in cancer survivors.
Important Safety Considerations
The primary care physician (PCP) or a fitness professional may need to modify exercise recommendations after careful evaluation of a number of factors, including type of cancer, extent of cancer spread, impact of surgical interventions, treatment modality, comorbid and pre-existing health conditions, and overall health status.
The ACSM guidelines state to consider the risk of an adverse cardiac advent before recommending exercise in the cancer survivor population. As long as the risk is considered low, no medical clearance or specific testing is necessary.
Commentary
Supported by more than 2,500 high-quality RCTs, the updated ACSM 2018 guidelines for exercise for cancer survivors elaborates on preliminary recommendations published in 2010. Although these guidelines can be applied to clinical practice immediately, it is important to highlight several limitations that may interfere with generalizing the findings. Most of the 2,500 studies recruited motivated volunteer participants, and many were conducted at academic or research institutions. The majority of the cancers involved were breast and prostate. Future research should expand to a more general population with a wider range of cancer types in the hope of providing targeted and specific guidelines. For now, the ACSM guidelines are a reasonable starting point for most any cancer survivor. Working with a provider, patients can individualize an exercise program to target specific health outcomes while capitalizing on strengths and recognizing any mitigating factors.
REFERENCES
- Simon, S. Facts & figures 2020 reports largest one-year drop in cancer mortality. Cancer.org. Published Jan. 8, 2020. https://www.cancer.org/latest-news/facts-and-figures-2020.html
- Statistics, graphs and definitions. Cancer.gov. Updated Nov. 8, 2019. https://cancercontrol.cancer.gov/ocs/statistics/index.html
- Jones L, Alfano C. Exercise-oncology research: Past, present, and future. Acta Oncol 2013;52:195-215.
- Wolin KY, Schwartz AL, Matthews CE, et al. Implementing the exercise guidelines for cancer survivors. J Support Oncol 2012;10:171-177.
