New findings on colon cancer suggest that regular exercise could potentially increase the expected survival rates of patients to match those of the general population.
A diagnosis of colon cancer no longer has to be a death sentence. Recent research has revealed that physical activity can be a potent tool in fighting cancer. While it may not be the first thing that comes to mind when thinking of cancer treatment, exercise can have a significant impact on a patient’s outcome.
Individuals who have battled cancer often face challenges in maintaining adequate physical activity levels, but experts provide guidance on how to achieve exercise goals.
Exercise and Colon Cancer Survival
The study analyzed data from two post-treatment clinical trials involving 2,876 individuals with stage 3 colon cancer. Stage 3 colon cancer indicates that the cancer has spread to nearby lymph nodes but has not yet reached distant organs. Participants reported their exercise levels following cancer surgery, as well as during and after chemotherapy. Researchers compared this data with that of the general population, matched by sex, age, and year.
The combined data from the two trials revealed that among the 1,908 individuals who were alive three years after cancer treatment, those who engaged in less than three MET (metabolic equivalent) hours had a 3.1 percent lower chance of surviving three additional years, while those who exercised 18 or more MET hours per week had a 2.9 percent higher likelihood of survival.
According to lead author Justin C. Brown of the Louisiana State University Health Sciences Center, three MET hours equal one hour of brisk walking, while 18 MET hours equate to five hours of brisk walking.
Underlying Mechanisms
The authors of the LSU study believe that exercise primarily extends survival by reducing tumor recurrence. While the exact mechanisms are not fully understood, several factors may be at play, including the reduction of systemic inflammation, decreased abdominal fat, and improved insulin sensitivity, which helps regulate blood sugar levels.
- Inflammatory markers: Exercise can lower levels of inflammatory markers, which contribute to tumor proliferation.
- Insulin and insulin-like growth factors: Physical activity can enhance insulin sensitivity and reduce levels of insulin and insulin-like growth factor 1, both linked to cancer progression.
- Body composition: Exercise promotes increased lean body mass and decreased fat mass, particularly in the abdominal area. Fat cells release adipokines, which affect inflammation, insulin resistance, and tumor growth.
- Oxidative stress: Exercise helps manage oxidative stress, which, if uncontrolled, can lead to DNA damage and tumor development.
- Microbiome: Regular exercise supports a healthier and more diverse gut microbiome, which boosts the body’s immune response and reduces inflammation, both crucial for cancer prevention.
“Research is ongoing to determine whether exercise affects these mechanisms independently or through interconnected pathways,” Owusu added.
Exercise and Survival in Other Cancers
According to the National Cancer Institute (NCI), studies suggest that exercise may also improve survival rates in individuals with breast and prostate cancer.
Randomized controlled clinical trials are currently underway to establish a direct link between physical exercise and cancer outcomes, mentioned Owusu. The NCI highlighted ongoing clinical trials involving individuals with breast cancer, colon cancer, and metastatic prostate cancer.
Challenges and Exercise Options
Cancer survivors encounter various obstacles when it comes to staying physically active, as noted by Ashley Perry, a physical therapist and cancer rehab navigator at Brooks Rehabilitation.
“Many patients experience high levels of fatigue or have multiple medical appointments that fill their schedules. Some patients are unsure if they are capable of exercising and may believe that remaining sedentary is their only choice. They also face the same psychological and emotional barriers that affect us all when it comes to sticking to an exercise routine.”
Despite these challenges, Brown believes that most cancer patients have the physical ability to meet the recommended exercise levels.
“Rather than recommending intense workouts, we suggest starting with simple activities like walking around the neighborhood. With a gradual progression, many cancer survivors can incorporate exercise into their routine,” Brown explained.
According to Perry, exercise can take various forms. While walking is a popular choice, engaging in any enjoyable physical activity, such as gardening, can also be beneficial as it increases the likelihood of forming a lasting habit.
- 150 to 300 minutes (2.5 to 5 hours) of moderate-intensity aerobic activity per week, 75 to 150 minutes of vigorous activity, or a combination of both
- Muscle-strengthening exercises at least two days per week
- Balance training
According to Perry, both resistance training and aerobic exercise are crucial but serve different purposes.
“Many patients experience a decline in cardiovascular fitness during and after cancer treatments, making aerobic activity essential for rebuilding endurance. Strength training helps improve circulation, reduces the risk of falls, and enhances daily activities,” Perry emphasized.
Finding the Right Balance
Individuals may wonder if there is a dose-response relationship, where more exercise leads to greater benefits. The LSU study suggests that higher levels of recommended physical activity offer a survival advantage. However, Perry believes that more is not always better, especially when starting a new exercise routine.
“We often see patients overexerting themselves on good days and then experiencing a crash in the following days. Additionally, there is a wave-like pattern of highs and lows that can be challenging to manage. We work closely with patients to find the right balance of activity. … It may require some trial and error to determine the appropriate exercise dose,” she explained.
The general consensus is that any amount of exercise is better than none for cancer survivors, according to Perry. She often advises patients to begin with just 10 minutes of low to moderate-intensity activity per day and gradually increase to meet the recommended minimum of 150 minutes per week. For patients who were highly active before their cancer diagnosis, she recommends starting at a lower level and progressing slowly to assess their body’s response. Seeking guidance from a physical therapist for personalized recommendations is highly recommended.
While gradually reaching the recommended exercise levels requires effort, the benefits are substantial. In addition to improving survival rates, regular physical activity can alleviate fatigue, anxiety, and depression, as noted by the NCI. However, the advantages extend beyond this, according to Dr. Kyle Eldredge, a colorectal surgeon in Palm Beach, Florida.
“For individuals undergoing treatment for colon cancer, exercise has been shown to reduce chemotherapy side effects, increase treatment completion rates, and enhance overall quality of life.”
