Role Of Physical Activity In Cancer Care

The treating oncologists and caregivers of a patient diagnosed with cancer are understandably immersed in providing onco-directed care as a priority. However, a holistic approach warrants that we do not ignore fatigue, depression, anxiety, lymphedema, sleep problems and subsequent reduced quality of life, often experienced by these patients during the course of treatment. Various treatment modalities for cancer can have a negative impact on cardiovascular, endocrine gastrointestinal, immune, nervous and respiratory systems, at times persisting beyond completion of treatment.

How can physical activity help?

Various animal studies have explored the molecular mechanisms that come into play after supervised exercise programs and regulate cell proliferation, angiogenesis and metastasis in cancer. Their clinical benefits have been highlighted in ample scientific literature published in the last decade.

A study on breast cancer patients undergoing chemotherapy or radiotherapy, observed that regular physical activity combined with an appropriate diet reduced the fatigue resulting from intensive cancer treatment. Combined aerobic and resistance exercise performed during chemotherapy resulted in improved sleep quality, reduced anxiety and depression and a positive impact on happiness in breast and colorectal cancer patients. Similarly, an 8-week exercise intervention programme consisting of twice-per-week sessions of 60 minutes of resistance, flexibility and cardiorespiratory exercises performed by patients with different types of cancer improved expression of positive emotions, functional capacity with a positive influence on mental health.

Combined aerobic and resistance exercise along with a low-fat, high-fibre diet reduces the incidence of metabolic syndrome (a known risk factor for breast cancer recurrence) in cancer survivors. A randomised controlled trial conducted among 100 breast cancer survivors, assigned either to exercise or usual care, showed an improvement in BMI and levels of circulating biomarkers, insulin, IGF-1, adiponectin and leptin, in the exercise group. An association between physical activity and reduction in mortality by 40–50% has been observed in colorectal, breast and prostate cancer patients.

Physical activity can improve immune system function by mobilizing leukocytes with increased functional capacity into the circulation. It may have an impact on CTLA-4 (inhibitory immune checkpoint) and improve the response to immunotherapy.

How much exercise/physical activity is recommended?

The type and extent of physical activity that can be recommended by the oncologist depends on the general condition of an individual patient and should be supervised by a trainer.

Widely endorsed recommendations from national and international health authorities suggest participation in 150 minutes of moderate-intensity aerobic exercise, 3–5 sessions per week, in addition to resistance training at least 2 days per week as part of a programme lasting 6–12 weeks.

What are the barriers to undertaking physical activity?

There may be a number of barriers preventing a patient from undertaking a sustained physical activity program such as the nature, type and extent of cancer; presence of metastases; cancer therapy and its side effects; patient’s attitude and coping strategy; social and family support; lack of an exercise partner or facilities in the vicinity; fear of injury; lack of willpower or interest; unavailability of information about the way and type of exercise.

The stress to continuously balance between treatment, family commitments and career often overrides the unwavering adherence to physical activity regimens, thus requiring reinforcement towards the latter by the treating oncologist.

Can physical activity be harmful to a cancer patient?

A systematic review of 129 published and unpublished trials with more than 12,000 participants was published in the Lancet in 2023. It concluded that the harms of exercise, prescribed alone or as part of multimodal interventions, is uncertain in patients with cancer undergoing systemic treatments due to high risk of bias, poor reporting, and lack of trials. An early evidence of a higher risk of fractures and thrombosis was found in exercise versus control groups and that these findings may be considered in future revisions of current cancer-specific exercise guidelines.

Conclusion

Physical activity improves aerobic fitness, mental health and reduces the side effects of cancer treatment, fatigue and mortality in cancer patients. Once a patient has been initiated to onco care, a concerted effort should be made by the treating team to direct the patient towards measures contributing to general well-being, including physical exercise; of course, taking into account specific requirements and contraindications for the same.

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