Effects of Exercise on Cancer Risk and Recurrence
Numerous epidemiological studies have found associations between higher levels of physical activity and reduced risk of developing certain cancers, such as breast, colon, and prostate cancer. Exercise may also reduce the risk of recurrence in cancer survivors.
Exercise during cancer treatment can help combat fatigue, improve physical functioning and quality of life, speed up recovery from surgery, and enable patients to better tolerate treatments such as chemotherapy and radiation therapy.
Studies on the mechanisms of exercise's anticancer effects have uncovered several specific pathways, including lowering sex hormone levels, reducing inflammation and oxidative stress, improving insulin sensitivity, enhancing natural killer cell activity, preventing tumor angiogenesis, and promoting cancer cell apoptosis.
Aerobic exercise and resistance training can help counteract muscle wasting and debility associated with some cancers and treatments. Physical activity helps preserve lean muscle mass.
Exercise supports mental health during cancer treatment by reducing anxiety and depression and improving self-esteem. Social benefits also result from exercise programs and classes.
Cancer patients can often safely engage in moderate physical activity under medical guidance, although some precautions may be necessary during intensive treatment periods, such as when bone marrow suppression is present.
Exercise guidelines for most cancer survivors recommend at least 150 minutes per week of moderate activity, plus 2-3 strength sessions, adjusted to individual fitness levels and health status.
Adopting a fit and active lifestyle can have a significant impact on our general health and well-being, as well as lower our chance of developing several cancers. Let's examine how exercise might work as your health maintenance ally.
How can exercise help prevent cancer?
Extensive research has demonstrated that maintaining an active lifestyle can dramatically reduce the risk of colorectal cancer. It's encouraging to see that those who lead active lives often have around half the risk of those who lead more sedentary lives. There is no sign of biased reporting, and this promising trend is consistent across different demographics and research approaches. The mechanisms underlying this protection are intriguing: exercise positively affects bile acid, prostaglandin, and insulin levels, all of which are important for the development and health of colon cells. Moreover, exercise maintains intestinal transit time, which lowers the colon's exposure to noxious compounds and may account for its protective effects.
Sex hormones are important in the development of endometrial and breast cancer. Exercise can lower the risk of certain tumors by positively impacting hormone synthesis, metabolism, and excretion. Participating in various activities can reduce breast cancer by 30%. At higher exercise levels, this link is more evident. Research suggests that physical activity may lower the risk of endometrial cancer, although the protective effect is stronger and more significant for colon cancer.
The situation with prostate cancer is complicated. Because athletes typically have lower testosterone levels, they may be more resistant to this kind of cancer. Nonetheless, inconsistent research findings have been reported, maybe as a result of variations in illness detection. Regarding testicular cancer, the information at hand is equivocal.
The relationship between physical exercise and lung cancer appears encouraging, although being less studied. Although there has been little research in this area, the majority of studies do point to a positive correlation between physical activity and a lower risk of lung cancer. This is notably the case for prospective cohort studies, which show a favorable dose-response association, especially in men, and repeatedly examine physical activity levels.
To sum up, leading an active lifestyle can lower your risk of developing several kinds of cancer in addition to improving your general health. It's an optimistic message that highlights the beneficial effects that ordinary everyday activities can have on our lives.
How can exercise help manage cancer during treatment?
Our participants found a sense of togetherness and shared experience in the power of physical activity, despite their individual post-cancer experiences. It was encouraging to learn that patients have noticed a strong correlation between improving their quality of life and physical exercise, irrespective of their past medical history or the amount of time they had been off therapy.
Studies in which individuals provided detailed accounts of how engaging in physical exercise enhanced their overall health, noted that exercise aided in their recuperation, and enhanced their ability to function in daily life. Physical activity became a ray of hope for many cancer survivors, helping them on their quest to regaining their strength and energy following treatment. They discussed how exercise was an effective way to manage their health and lessen the terrifying possibility of a cancer recurrence. Finding out how hard they tried to include regular physical activity into their daily lives was incredibly inspiring.
Patients have found comfort and happiness in the embrace of physical activity, even during stressful times. They told touching tales of how exercising had lifted their spirits, given them more energy, and given them a fresh perspective on life. Their mental health found refuge in the outdoors and comfort in the face of stress from the simple act of returning to familiar physical pursuits. These beneficial psychological aspects were crucial to their post-treatment changes, as well as to their dedication to physical activity.
The health benefits of physical activity on the body are truly amazing. It skillfully manipulates immunological response, inflammation, and metabolic growth factors to create a milieu that makes cancer metastasis difficult to establish. Studies have shown that fluid shear stress can affect cell viability, intracellular properties, growth rates, and the metastatic potential of circulating tumor cells. Mechanical forces are involved in the onset and progression of metastasis. Research has indicated that physical activity may shrink tumor cells in people with colon cancer, which is especially encouraging. These results highlight the significant and direct effects that physical activity can have on cancer cells through mechanisms such as shear stress in the vasculature.
Overall, the participants’ experiences show how engaging in physical activity may be a healing and uplifting experience for those who have experienced cancer. It is evidence of the body's tenacity and the enduring strength of the human soul.
How can exercise help manage cancer recurrence?
Engaging in regular physical activity can have a wonderfully positive impact on your health, including reducing the risk of cancer recurrence and mortality. It's truly remarkable how various biological mechanisms come into play, contributing to this protective effect.
Physical activity isn't just about moving your body; it's about creating a harmonious environment within you. Most research has delved into how physical activity affects the intricate world inside us, particularly in the realm of the tumor microenvironment. It influences growth factors, inflammation, and immunity, all of which are key players in determining how cancer cells thrive.
Physical activity has a unique way of balancing the levels of inflammation in your body. While it might seem paradoxical, it's actually quite fascinating. Take GlycA, for instance, a marker of inflammation that has implications for cancer risk and prognosis. By examining it, we gain deeper insights into how exercise relates to inflammation and, subsequently, cancer.
In a study, women with breast cancer found that muscle-strengthening activities actually reduced C-reactive protein, a marker of inflammation. And right now, there's an ongoing study looking into the effects of aerobic activity on patients with colon cancer. These efforts are shedding light on the potential benefits of exercise in different cancer contexts.
Speaking of benefits, moderate aerobic exercise isn't just good for your cardiovascular health; it's a boon for your immune system too. It encourages the mobilization of natural killer cells, T cells, and B cells—your body's frontline defenders. These immune warriors have a crucial role to play in how your body deals with cancer.
In recent times, with the advent of immune checkpoint inhibitors, the landscape of cancer treatment has transformed. Understanding the composition of immune cells has become pivotal in assessing cancer risk and prognosis, highlighting the intricate connection between your immune system and cancer.
Evidence-Based Techniques to Motivate Survivors to Be More Active
The goal of oncology care teams is to accompany patients on their path to improved health and wellbeing. We recognize that working out may not always seem fun or simple to many cancer survivors. We do, however, wish to stress that there are practical strategies to turn physical activity into a more enjoyable and meaningful aspect of your life.
Finding physical activities that make you happy and satisfied is one important strategy. Finding what makes you smile may make exercise much more enjoyable, whether it's going for a leisurely walk while listening to your favorite audiobook, playing a game with friends, or working out with a partner.
Another crucial phase in this process is setting realistic goals. Your initial objective might be as easy as going for a daily 5-minute walk. You may create a long-lasting habit and feel more comfortable with physical activity by making some minor adjustments. Remember to set both short- and long-term objectives to maintain your motivation. For example, you could schedule weekly walks lasting twenty minutes on particular days. Set easy-to-achieve goals first, then progressively step up the difficulty as you gain confidence in yourself.
Monitoring your development is a great method to keep yourself motivated. You can track your physical activity with wearable technology or by noting the days you work out on a calendar. Not only may gadgets like wearable activity monitors and pedometers encourage you to be more active, but they can also enhance your general health.
We also wish to stress how important social support is. Support, in the form of both material and psychological support, is essential for increasing physical activity. To make extra time for exercise, think about finding workout partners or someone who can help with everyday tasks. Finding people who are encouraging can help you get over difficulties and make the transition to a more active lifestyle simpler. Remember that your medical staff is available to assist your emotional health by offering advice, motivation, and aftercare.
What is known about the relationship between physical activity and cancer risk?
Being physically active helps protect against cancer. Observational studies show positive outcomes across diverse populations, giving reason for optimism. High levels of physical activity reduce bladder cancer risk by 15%. Dedicating time to leisure-time physical activity can reduce bladder cancer risk by 13%, according to a comprehensive analysis of over 1 million individuals.
Staying physically active lowers the risk of breast cancer. Physically active women have a 12-21% lower risk of breast cancer, according to a 2016 meta-analysis of 38 cohort studies. Physical activity reduces breast cancer risk for both premenopausal and postmenopausal women.
In a 2016 meta-analysis of 126 studies, an uplifting discovery was made about colon cancer. Highly active individuals had a 19% lower risk than less active individuals. Active women have a 20% lower risk of endometrial cancer compared to those with low physical activity levels. Maintaining a healthy body weight is important to reduce the risk of endometrial cancer.
Physical activity helps fight esophageal adenocarcinoma and kidney cancer. Physically active individuals have a 21% lower risk of esophageal adenocarcinoma and a 12% lower risk of kidney cancer. Leisure-time physical activity reduces kidney cancer risk by 23% in over 1 million people.
Physically active individuals have a 19% lower risk of stomach cancer, according to a 2016 meta-analysis. Physical activity may lower lung cancer risk for former and current smokers.
An active lifestyle contributes positively to overall health and well-being, although evidence is limited for certain cancers like blood cancers, pancreatic cancer, prostate cancer, ovarian cancer, thyroid cancer, liver cancer, and rectal cancer. Let's appreciate the benefits of an active life, which can protect and improve our health in many ways.
Exercise and feedback loops
Physical activity helps our body grow and adapt. Exercise promotes growth and well-being. This transformation manifests as heightened breathing, heart rate, flushed skin, and perspiration. You may feel thirsty as your body seeks balance.
Muscle cells use oxygen to transform glucose into ATP, fueling muscle contractions. Exercise helps muscles get more oxygen. You'll take deeper breaths to nourish your body's tissues. Your heart pumps oxygen-rich blood to the muscles and organs.
Muscles produce carbon dioxide and water during cellular respiration. To maintain balance, these remnants must exit. Your increased breath and heart rhythm remove excess carbon dioxide and water, restoring serenity. ATP fuels our muscles and produces warmth. Our bodies dilate blood vessels and produce sweat. The dance of thermoregulation keeps the body's temperature comfortable. Sweat evaporates, taking away body heat.
Exercise increases sweat and breath, causing the body to draw in more water and salts. Be mindful of excessive consumption, as it can cause imbalance and dehydration, affecting your body's functions. When your blood runs low, your body releases hormones to guide you to replenishment. In the kidneys, concentrated urine is created to maintain fluid balance with less water.
Embrace exercise as a testament to your body's wisdom. It is a loving guardian that guides you towards harmony and balance, asking only for your care and acknowledgment of its devotion to your well-being.
The various roles played by exercise
Exercise has been widely studied for its effects on health, including its impact on cancer risk and recurrence.
Hormones
One of the primary mechanisms by which exercise may influence cancer risk is through weight control. Being overweight or obese has been associated with increased cancer risk and mortality. Exercise helps individuals maintain a healthy body weight, thereby reducing the risk of obesity-related cancers.
Another key factor in exercise's effect on cancer is hormone modulation. Exercise is known to lower levels of sex steroid hormones, such as estrogen, testosterone, and androgens. Elevated levels of these hormones have been associated with an increased risk of certain cancers, including breast, prostate, and endometrial cancers.
Additionally, exercise has been shown to reduce excess insulin and insulin-like growth factor-1 (IGF-1), both of which have been suggested to contribute to cancer growth.
Immune system
In addition to its effect on hormones, exercise also plays a role in modulating the immune system.
Exercise has been shown to boost the activity of cytotoxic innate immune cells, such as natural killer cells, which target and destroy cancerous or precancerous cells. Moreover, exercise has been associated with increased T cell counts and enhanced function of the adaptive immune system, further contributing to anti-tumor immunity.
Other roles
Exercise has also been identified as a key factor in reducing chronic inflammation, which has been linked to an increased risk of cancer. By lowering levels of inflammatory cytokines and reducing tissue inflammation, exercise creates an environment less conducive to cancer growth.
Finally, exercise has been shown to have anti-oxidative effects, helping to counteract the damage caused by carcinogenic reactive oxygen species (ROS). Exercise training enhances the body's endogenous antioxidant systems, thereby helping to mitigate DNA damage and reduce the risk of cancer development.
Taken together, these interrelated mechanisms contribute to the protective effects of exercise against cancer. It's important to note that these effects are likely synergistic, meaning that they work together to reduce cancer risk rather than operating in isolation. Further research is needed to fully elucidate the precise mechanisms by which exercise confers protection against cancer.
Lowering sex hormone levels
Physical activity reduces circulating estrogen in women and testosterone in men, which may suppress hormone-sensitive cancers like breast and prostate. Exercise also reduces body fat levels, leading to decreased production of estrogen from fat tissue. Increased liver clearance of sex hormones is another potential mechanism.
Improving immune function
Exercise mobilizes natural killer cells and cytotoxic T-cells that can detect and destroy cancer cells. Myokines released from exercising muscles also limit tumor growth. Enhanced immunity may also improve the efficacy of cancer treatments.
Potential Mechanisms
The mechanisms underlying the tumor growth-inhibitory effects of exercise are multifaceted and likely involve several interconnected factors, including changes in the immune response, reduction of inflammation, enhanced blood flow, increased oxidative stress in the tumor microenvironment, and altered hormonal and metabolic environments. Exercise can also induce the release of various circulating factors, such as myokines and exerkines, which can exert anti-cancer effects.
Reducing inflammation
Exercise reduces inflammatory factors like IL-6, TNF-alpha, and CRP, which can promote cancer development. Improved insulin sensitivity may also lower inflammation, as insulin resistance creates a pro-inflammatory state.
Restricting angiogenesis
Physical activity can reduce pro-angiogenic factors like VEGF, which allow tumors to form new blood vessels for nutrient supply.
Clinical Implications
These findings have important clinical implications for cancer prevention and management. Exercise interventions could be incorporated into cancer prevention strategies, as well as included in the comprehensive care of cancer patients, to optimize health outcomes. However, it is essential to consult with healthcare professionals to tailor exercise recommendations based on individual needs and conditions.
Increasing antioxidant capacity
Exercise boosts natural antioxidant defenses, helping to combat oxidative stress that can damage DNA. Training leads to increased levels of SOD, glutathione, and other endogenous antioxidants.
Inducing apoptosis
Exercise leads to metabolic changes in muscles that release exerkines into circulation, which induce apoptosis and anti-proliferation effects on cancer cells.
Overall, these diverse exercise-induced effects create an anti-tumor environment, lowering cancer risk factors while increasing protective mechanisms. Further research is needed to fully understand these molecular pathways in humans.
When muscles contract during exercise, they release a multitude of compounds including myokines, metabolites, exosomes, and other factors collectively known as exerkines. These exerkines can enter the circulation and directly act on tumor cells to alter their biology.
For example, specific exerkines like oncostatin M and SPARC induce apoptosis and halt proliferation of cancer cells through activation of intracellular signaling pathways like JAK-STAT. Irisin released from muscle also has anti-proliferative effects. Restricting angiogenesis is another key mechanism - exercise reduces levels of pro-angiogenic proteins like VEGF, limiting blood vessel growth that supplies tumors with oxygen and nutrients.
Exercise also remodels whole-body metabolism, with effects on cancer cell nutrient availability and usage. Many malignant cells rely heavily on anaerobic glycolysis for energy production and biosynthetic needs. But exercise acutely drops blood glucose and insulin, restricting tumor access to this key proliferative fuel.
In response, cancer cells must ramp up dysfunctional mitochondrial metabolism and increase use of other substrates like fatty acids or amino acids. This metabolic flexibility forced by exercise can promote cancer cell death due to mitochondrial oxidative stress. Exercise drives mitochondrial biogenesis and oxygen consumption in tumors through pathways like PGC-1α.
On a systemic level, exercise also boosts anti-tumor immunity and blood flow. Natural killer cells and T cells are mobilized to attack malignancies. Improved circulation enhances drug delivery. Reduced inflammation and sex hormones contribute to anti-cancer effects as well.
In summary, exercise employs a multi-level assault on cancers through direct exerkine actions, metabolic perturbation, immune activation, and systemic modulation. Elucidating these mechanisms aims to harness exercise as targeted medicine specific to cancer types and treatments. Current evidence clearly supports exercise as an adjunct therapy that can suppress tumor progression while also improving physical health and quality of life.
Mechanisms by which exercise may influence cancer
Effects of Exercise on Cancer Risk and Recurrence
Research has shown that increased physical activity is linked to a reduced risk of cancer and lower recurrence rates. In large prospective cohort studies, people who reported the highest levels of recreational physical activity had a 20-40% lower risk of developing colon, breast, endometrial, and other cancers compared to those with the lowest levels of activity. A dose-response relationship has been observed in many studies, with cancer risk decreasing incrementally as exercise amount and intensity increase.
Exercise during adolescence and early adulthood appears to be particularly protective against postmenopausal breast cancer, which occurs during mammary development. Meta-analyses estimate that there is a 10-20% lower risk of breast and colon cancer recurrence in individuals with higher levels of physical activity after diagnosis, and improved survival has been noted.
The effects of exercise seem to be most pronounced for cancers influenced by obesity and sex hormones, such as breast, endometrial, and prostate cancers. However, there is the potential for confounding from correlations between exercise and other lifestyle factors like diet, alcohol use, and smoking. Despite this, associations remain in multivariate analyses.
Randomized trials examining exercise training in cancer patients support a causal risk reduction, with improvements observed in insulin levels, inflammation, and immunity. The exact mechanisms through which exercise lowers cancer risk are not yet fully understood, but proposed mediators include weight control, sex hormones, metabolic hormones, immune function, and anti-inflammatory effects.
While the optimal timing, duration, and types of physical activity for cancer prevention have yet to be fully defined, there is considerable epidemiologic data indicating that exercise and physical activity significantly lower cancer incidence and recurrence. Further study on the precise mechanisms and prescription recommendations is needed.
Effects of exercise on cancer cells
Exercise drives several changes in cancer cells that can lead to their death or increased susceptibility to chemotherapy, known as chemosensitization. One of these changes is in lipid metabolism. Exercise-induced increases in mitochondria within tumor cells lead to the upregulation of enzymes and proteins involved in fatty acid oxidation. This allows the cancer cells to use fatty acids, ketones, and other lipids for energy. However, tumor mitochondria often struggle with high oxidative loads, and this reliance on lipids can be problematic.
Metabolic dysfunction can result in cancer cell death. When forced to rely more on mitochondrial respiration, especially with their dysfunctional mitochondria, cancer cells can experience a fatal metabolic crisis. They may struggle to adapt to utilizing lipids and oxidative metabolism, leading to ATP depletion, cell starvation, and the activation of cell death pathways. Accumulated lipids can cause lipotoxicity and apoptosis. Excess fatty acids and lipid intermediates may generate reactive oxygen species and alter membrane fluidity, leading to oxidative cell death.
Metabolic dysfunction can also lead to chemosensitization. Exercise can reduce glycolysis and glucose availability in cancer cells, limiting their metabolic options when treated with chemotherapy. Inhibiting one metabolic pathway with drugs becomes more effective, as cancer cells can't easily switch to another pathway. Increased reliance on oxidative phosphorylation makes some cells more vulnerable to redox-modulating chemotherapy. Lowered NADPH (this is an element of how cells produce energy) production also reduces the cancer cells' ability to detoxify some cancer drugs. Exercise-preconditioned stromal cells may release factors that increase cancer cell sensitivity to chemotherapy.
Exercise may also increase the immune system's ability to attack cancer cells. Heat shock proteins induced by exercise could increase tumor antigen presentation. Exercise might also upregulate MHC class I proteins, promoting immune recognition of cancer cells. Increased exposure of calreticulin could further stimulate immune attacks on malignant cells. However, these mechanisms need further study in cancer models.
In summary, exercise affects tumor metabolism and the immune response, leading to cancer cell death and increased susceptibility to chemotherapy. Exercise-induced changes in lipid metabolism, combined with the inherent mitochondrial dysfunction of cancer cells, can result in metabolic crises that cause cell death. Exercise may also boost the immune system's ability to recognize and attack cancer cells.
Exercise has a significant impact on tumor growth kinetics and tumor formation. The mechanisms underlying these effects are still under investigation, but it is clear that regular exercise can contribute to tumor growth inhibition.
Here are some key findings and implications:
Inhibition of Tumor Growth
Exercise has been shown to inhibit the growth of established tumors. Preclinical studies have found that the rate of tumor growth can be reduced with exercise training. However, exercise alone is not capable of directly eradicating tumors. The inhibitory effect of exercise is observed across various cancer histologies.
Remarkably, cancer cells grown in serum from exercised individuals form many fewer colonies compared to cells grown in serum from non-exercisers. This shows exercise may reduce the clonogenic potential of cancer cells - their capacity to proliferate and spread uncontrollably.
Scientists also inject cancer cells into sedentary mice to observe tumor formation. When cancer cells are first mixed with serum from exercised people before injecting them, the cells form far fewer tumors in the mice compared to cells pre-treated with non-exerciser serum.
So in both lab studies and animal models, something in the blood of exercised individuals appears to lessen the seeding ability of cancer cells and restrict their out-of-control growth. This unique anti-cancer effect of exercise warrants further exploration.
In Vitro Studies
Several studies have used exercise-conditioned serum to incubate cancer cells of different origins (breast, prostate, lung cancer) to investigate the effect of exercise on cancer cell proliferation. In these in vitro studies, an inhibition is observed compared to the control setting. Although this inhibition level is not as high as seen in long-term in vivo exercise interventions, it is still noteworthy, especially when considering that this level of inhibition could accumulate to a clinically significant effect with consistent exercise.
Immunological Control of Tumor Growth
Exercise can regulate the cellular immune system, mobilizing cytotoxic immune cells (such as natural killer or NK cells) into circulation. This process is believed to be driven by factors like blood flow-induced shear stress and adrenergic signaling. Once in the circulation, these immune cells can survey the body to identify and eradicate transformed (cancerous) cells. Exercise has been found to suppress tumor growth through an epinephrine-dependent mobilization of NK cells, which then infiltrate tumors. Beta-blocker treatment, which inhibits adrenergic signaling, has been shown to reduce this suppression of tumor growth and the mobilization and infiltration of NK cells.
Seeding and Clonogenic Potential
When cancer cells are grown in a lab setting, their ability to form colonies reflects how aggressive and quickly-spreading they are. Scientists can take blood serum from people who exercise and use it to grow cancer cells in the lab.
Muscle-to-Tumor Crosstalk
Skeletal muscle releases peptides called myokines during contractions, which are thought to regulate energy exchange and promote metabolic adaptations in muscles and other organs. Myokines have been suggested to have a role in cancer protection, though evidence is still limited. Some myokines, like Oncostatin M (OSM) and Irisin, have been shown to inhibit breast cancer cell viability in vitro. Others, like SPARC, have been shown to reduce tumorigenesis in the colon of exercising mice. Additionally, exercise-induced myokines may affect immune cell activity by releasing immune-regulatory cytokines like IL-6, IL-7, and IL-15, which are known to promote NK and T cell proliferation, differentiation, and maturation.
Research Gaps
Observational studies show a link between physical activity and reduced cancer risk. These studies don't completely eliminate the possibility that active people have a lower cancer risk due to other healthy lifestyle behaviors. Randomly assigning participants to exercise interventions in clinical trials provides strong evidence by eliminating bias caused by pre-existing illness and physical inactivity.
Large clinical trials are studying physical activity and exercise interventions in cancer patients and survivors to confirm evidence and determine the potential impact. These trials include the BWEL trial for breast cancer patients, the CHALLENGE trial for colon cancer patients after chemotherapy, and the INTERVAL-GAP4 trial for men with metastatic prostate cancer.
Many unanswered questions remain in research on physical activity and cancer, such as:
How does physical activity reduce cancer risk?
What is the best physical activity regimen to reduce the risk of cancer?
Does sedentary behavior increase cancer risk?
Does physical activity's association with cancer vary by age or race/ethnicity?
Does physical activity lower cancer risk in people with inherited cancer risk genes?
Takeaways
The effects of exercise on tumor development and progression can be summarized as follows: During exercise performance, the release of several systemic factors (catecholamines, myokines, etc.), sympathetic activation, increased blood flow, shear stress, and increased temperature exert immediate stress on tumor metabolism and homeostasis. Following long-term training, these acute effects lead to intratumoral adaptations, such as improved blood perfusion, enhanced immunogenicity, and metabolism adjustments, which contribute to slower tumor progression.
It is important to note that these findings are based on preclinical and clinical studies, and the specific effects of exercise on tumor growth and progression may vary depending on factors such as cancer type, exercise type, and individual patient characteristics. Further research is needed to fully understand the mechanisms underlying the effects of exercise on tumor development and progression and to optimize exercise interventions for cancer prevention and treatment.
https://www.cell.com/cell-metabolism/pdf/S1550-4131(17)30567-3.pdf
https://academic.oup.com/epirev/article/39/1/71/3760392
https://www.sciencedirect.com/science/article/pii/S2095254620300958