- Structured exercise after cancer treatment may be linked to reduced risk of cancer recurrence and mortality, according to a recent study.
- Aerobic exercise, either alone or combined with resistance training, showed the strongest benefits for overall survival.
- Experts recommend working with a cancer care team to create a suitable exercise plan based on individual circumstances.
Cancer recurrence varies significantly depending on the type of cancer. While there is no certain way to prevent recurrence — when cancer returns after treatment — researchers have investigated potential ways to minimize the risk where possible.
Physical activity is already recognized as a benefit for people with cancer. The American Cancer Society notes that it may offer benefits before, during, and after cancer treatment.
Now, a study published in September in the British Journal of Sports Medicine has found that structured exercise — physical activity that is intentional and part of a routine — may be associated with longer survival and a lower risk of cancer recurrence after treatment.
The benefits appeared to be strongest in people who had early stage cancer and in those who performed aerobic exercise.
The study authors found that participants who followed structured exercise were 17% more likely to live without cancer recurrence. There was also a 26% lower risk of dying from cancer.
For the study, researchers examined information from 21 randomized controlled trials involving 8,449 participants. The three cancers that were most frequently studied included:
The researchers found that those who engaged in structured exercise experienced:
- improved overall survival
- improved disease-free survival
- lower all-cause mortality
- lower cancer-specific mortality
Diana Garrett, PT, DPT, FAAOMPT, CLT, CSCS, board-certified orthopedic clinical specialist and program director of physical therapy services of the Women’s Health & Wellness Institute at Providence Saint John’s Health Center in Santa Monica, CA, spoke with Medical News Today about these findings.
“Physical activity is essentially a systemic intervention that involves multiple organ systems, including the cardiovascular system and immune system, which leads to overall benefits to patients. Exercise leads to increased cardiac output to meet oxygen demands during activity, which can lead to a more efficient heart,” explained Garrett, who was not involved in the study.
She added, “Regular exercise has shown to increase immune activity, which may be especially important in patients with a history of cancer.”
Findings also suggest that individuals who closely followed the exercise plan, with a high adherence of 70% or more, were more likely to experience greater benefits.
Additionally, benefits appeared more pronounced in people with early stage cancer and those doing aerobic exercise.
“I think this should not be read that patients with early stage cancer benefited more, but looking more closely at the different studies this meta-analysis pulled,” said Garrett.
“The studies with patients that had more advanced-stage cancers tended to have a smaller sample size, which would alter the interpreted outcomes. Also, patients with more advanced-stage cancers may undergo different treatments that may render it more difficult to participate in exercise.”
The study found that aerobic exercise and combined aerobic exercise and strength training led to improved overall survival.
Aerobic exercise alone had a 29% lower relative risk of death, while aerobic exercise and resistance training had around a 25% lower relative risk. Resistance training alone showed no statistical significance in the analysis.
Mike Lattanzi, MD, a board-certified medical oncologist and Director of the Genitourinary Cancer Research Program at Texas Oncology, told MNT:
“Any kind of physical exercise, whether aerobic or weight training, brings about myriad cellular and tissue changes throughout the body.”
Lattanzi, who was not involved in the study, added that, “[s]pecifically, it is hypothesized that exercise might impair cancer cell metabolism and enhance the efficacy of antitumor immune cells.”
The American Cancer Society explains that exercise is generally safe for most people before, during, and after cancer treatment.
However, there are some factors that individuals may need to consider.
Garrett explained that “[t]he main safety considerations when recommending exercise should be determined based on an individual basis. It should take into consideration the patient’s prior activity level, the treatment they received, any prolonged toxicities or side effects from treatment, their current cardiovascular and overall health, and any physical impairments they may have.”
She added, “For example, certain chemotherapy medications can have a detrimental effect on the cardiovascular system, and therefore intensity of exercise may need to [be modified] to ensure tolerance for activity. Or exercise may need to be performed in a controlled environment to mitigate any stress on the immune system.”
Other factors, such as the age of the individual, may also need to be considered.
Lattanzi explained that, “[f]or a young, physically fit patient with cancer, it’s difficult to see any serious risk to the patient resulting from structured exercise. For more frail or elderly patients, musculoskeletal injuries incurred over the course of physical activity can lead to diminished mobility, which would likely have a negative impact on patient outcomes.”
He concluded, “Obviously, any recommended exercise intervention should be tailored to each patient’s fitness.”
While the study found that structured exercise, particularly aerobic exercise, could be beneficial for people receiving cancer treatment, it does not mean that everybody should follow the same routine.
It is best for anybody undergoing or having finished cancer treatment to discuss their physical activity with their doctor or cancer team.
“I think the best way to create a safe exercise program is to work with a team to coordinate your activity,” said Garrett.
“As a physical therapist, I like to consult with a patient’s oncologist, primary care physician, and/or cardiologist if available to set a target heart rate and understand if modifications are needed to ensure immune health,” she explained.
“It is important to do a baseline testing to see where a patient’s cardiovascular fitness is and what their baseline strength is in order to build a program upon that.”
