Epidemiology – You are not alone…
Projections from the Australian Institute of Health and Welfare estimated there would be 145 000 new diagnoses of cancer in 2020, of which 13.7% would be breast, 11.5% prostate, 10.7% colorectal and 9.1% lung.
Unsurprisingly then, breast cancer is most common form of cancer in females, accumulating to three-times the runner up. For men, prostate cancer leads the way with twice the incidence of runners up if skin cancer is not included1.
In some good news, thanks to earlier detection, greater awareness and better treatment options, an individual’s five year survival rate has increased from 50% to 70% on average across all cancers over the last 30 years1. However, cancer still remains one of the leading causes of death in Australia for over 45’s, competing against coronary artery disease, cerebrovascular disease, COPD and dementia2.
So what is cancer and what causes it?3
It all starts at the cellular level. Cells are the functioning building blocks of our body that continuously divide before naturally dying through a process called apoptosis when they are too old and not functioning to their fullest. Tumours begin their development when there is an error in cell division that goes undetected and creates further errors when continuing to divide. For the most part, our bodies are able to kill off these abnormal cells before they cause too much concern but with continual exposure to certain stresses, cells begin to mutate and create an unwanted tumour. Potential mutagens leading to such events can be caused by non-modifiable (things you can’t change) and modifiable (things you can change) risk factors3-4.
- Non-modifiable: Gender, genetics and age
- Modifiable: Smoking, alcohol, sedentary behaviour, diet, obesity, some viruses, UV exposure and the environment (carcinogens – asbestos, chromium, nickel compounds).
Benign vs malignant tumours:3
For tumours to become malignant, some essential alterations need to take place.
- Self-sufficiency in growth signals: Cells divide without being told to
- Neglects growth inhibitory signals
- Evasion of apoptosis
- DNA repair attempts on the cell are unsuccessful
- Sustained angiogenesis – own blood supply feeding glucose to the tumour for growth and creating its own environment
As a result, the main differences for a malignant tumour involve their ability to potentially spread to other locations in the body, cell size & appearance as further mutations have occurred and generally they grow faster, as visualised through the ‘10 Hallmarks of Cancer’.
Assessment with an Exercise Physiologist and how exercise can help...
Although the prevalence of cancer remains high, it is important to remember that your experience is quite individual and as such we want to;
- Find out your story
- See where you are up to with your treatment – upcoming, ongoing or previous
- What it involves (chemotherapy, radiation, surgery, etc) and the anticipated timelines
- Determine how it has impacted you (side effects), whether that be physically, psychophysically or psychologically through cachexia, muscle wastage, increased fat, bone mineral density reductions, peripheral neuropathy, pain, fatigue, decreased quality of life, anxiety, depression or whether you are immunocompromised.
Side effects throughout cancer treatment are common and predictability remains low for when and how it will impact the host. Bone mineral density (BMD) reductions equating to 13% have been shown in some studies of women with breast cancer with further losses occurring post treatment5. Additionally, muscle wastage is a common theme throughout the treatment phase, sometimes leading to cachexia in later stages (>5% loss in body weight6) for approximately 35% of patients, whilst approaching 90% in patients with pancreatic cancer7. Moreover, hot, burning or neural sensations, known as peripheral neuropathy occurs in 61.8% of patients in the first month of starting chemotherapy depending on the drugs used before reducing to 30% at six months8.
So how can exercise be your best friend?
The overarching goal is to reduce the amount of impact necessary treatment has on the body through the introduction of strategies to monitor and target the physiological, psychophysical and psychological side effects. It is to also boost the success of the treatment by being healthier and stronger to take on treatment dosages.
Evidence has shown that a single bout of aerobic exercise can improve a patient’s energy and reduce nausea immediately after training whilst reducing stress hours later in women undergoing chemotherapy for breast cancer9. Furthermore, undertaking consistent aerobic exercise during treatment results in increased cardiovascular fitness, improvements in overall body strength and decreases in the rate of BMD loss10. And similar results are seen when women with breast cancer perform resistance training as an exercise modality during their chemotherapy treatment10. Adding to this evidence, studies have also shown that men undertaking androgen deprivation therapy for prostate cancer can increase muscle tone and function, BMD and reduce fat increases11. Moreover, both aerobic and resistance training have been shown through countless studies to reduce the risk of all-cause mortality from further chronic disease development in the future and fatality directly from one’s breast cancer12. Lastly, research is emerging on the role exercise plays in delaying tumour growth and increasing cell death when conducted in conjunction with medical treatment for humans. This is the result of studies being conducted on mice showing positive results through increased vacuolisation (blood supply) to tumours and hence, a greater amount of the treating drug reaching the cancerous cells13.
How may an Exercise Physiologist assist with your cancer journey?
- Direct/ guide you in the right direction towards your goals.
- Create a plan that you enjoy and works for you throughout varying stages of treatment.
- Offer a safe environment to exercise if home isn’t your thing and you are immunocompromised.
- Provide education throughout your journey.
- Look after your physiology (muscle mass, BMD, fat mass) by giving you appropriate exercises or activities.
- Create and implement strategies to manage fatigue and pain - if it presents.
- Have you return to previous activities where possible (social, ADLs, home/everyday tasks) through functional based training.
- Implement realistic and attainable lifestyle changes to reduce the risk factors associated with cancer or other chronic conditions.
A few key take home messages…
- You are not alone through your cancer journey – support networks are available.
- Side effects are common during cancer treatment and severity differs between everyone.
- Although you may feel mentally and/or physically drained, exercise could help.
- Seeing an exercise physiologist with a specialty in cancer care is a great way to obtain some guidance throughout your journey – Pre, during and post treatment.
Whether it’s just a chat, additional info, ways to donate or events to take part in, visit the Cancer Australia website for more information regarding your specific cancer and links to organisations devoted to offer a helping hand…
Look out for future blog posts looking into specific cancers and how exercise can help!
- (2020). Cancer Data in Australia. Retrieved from Australian Institute of Health and Welfare: https://www.aihw.gov.au/reports/cancer/cancer-data-in-australia/contents/summary
- (2020). Deaths in Australia. Retrieved from Australian Institute of Health and Welfare: https://www.aihw.gov.au/reports/life-expectancy-death/deaths-in-australia/contents/leading-causes-of-death
- The American Cancer Society. (2017). The American Cancer Society's Principles of Oncology: Prevention to Survivorship. Hoboken, NJ : Wiley Blackwell.
- Blackadar, C. B. (2016). Historical review of the causes of cancer. Retrieved from World Journal of Clinical Oncology: doi: 10.5306/wjco.v7.i1.54
- Khan, M. N., & Khan, A. A. (2008). Cancer treatment-related bone loss: a review and synthesis of the literature. Retrieved from Current Oncology: doi: 10.3747/co.2008.174
- Fearon, K., Strasser, F., Anker, S. D., Bosaeus, I., Bruera, E., Fainsinger, R. L., & Baracos, V. E. (2011). Definition and classification of cancer cachexia: an international consensus. Retrieved from The Lancet Oncology: DOI : 10.1016/S1470-2045(10)70218-7
- Sun, L., Quan, X.-Q., & Yu, S. (2015). An epidemiological survey of cachexia in advanced cancer patients and analysis on its diagnostic and treatment status. Retrieved from Nutrition and Cancer: https://doi.org/10.1080/01635581.2015.1073753
- Serenty, M., Currie, G. L., Sena, E. S., Ramnarine, S., Grant, R., MacLeod, M. R., . . . Fallon, M. (2014). Incidence, prevalence, and predictors of chemotherapy-induced peripheral neuropathy: A systematic review and meta-analysis. Retrieved from Pain: http://dx.doi.ord/10.1016/j.pain.2014.09.020
- Johnsson, A., Demmelmaier, I., Sjovall, K., Wagner, P., Olsson, H., & Tornberg, A. B. (2019). A single exercise session improves side-effects of chemotherapy in women with breast cancer: and observational study. Retrieved from BMC Cancer: https://doi.org/10.1186/s12885-019-6310-0
- Schwartz, A. L., Winters-Stone, K., & Gallucci, B. (2007). Exercise effects on bone mineral density in women with breast cancer recieving adjuvant chemotherapy. Retrieved from Oncology Nursing Forum: doi: 10/1188?07.ONF.627-633
- Dawson, J. K., Dorff, T. B., Schroeder, E. T., Lane, C. J., Gross, M. E., & Dieli-Conwright, C. M. (2018). Impact of resistance training on body composition and metabolic variables during androgen deprivation therapy for preostate cancer: a piolt ranomised controlled trial. Retrieved from BMC Cancer: https://doi.org/10.1186/s12885-018-4306-9
- Wirtz, P., & Baumann, F. T. (2018). Physical activity, exercise and breast cancer - What is the evidence for rehabilitation, aftercare, and survival? A review. Retrieved from Breast Care: DOI: 10.1159/000488717
- Betof, A. S., Lascola, C. D., Weitzel, D., Landon, C., Scarbrough, P. M., Devi, G. R., . . . Dewhirst, M. W. (2015). Modulation of Murine Breast Tumor Vascularity, Hypoxia, and Chemotherapeutic Response by Exercise. Retrieved from Journal of the National Cancer Institute: doi: 10.1093/jnci/djv040