Cancer remains one of the most formidable health challenges of our time, a relentless disease that disrupts lives and claims millions of victims worldwide. It is the uncontrolled growth of abnormal cells, invading healthy tissues and spreading like wildfire through the body. According to the World Health Organisation (WHO), cancer was responsible for an estimated 9.6 million deaths in 2018—making it the second leading cause of death globally.
Yet, even as medical science advances in treatment options, the battle against cancer is far from over. Experts warn that the global burden is set to rise sharply, with projections suggesting over 35 million new cases by 2050—a staggering 77 per cent increase from 2022 figures. Oncologists have also stated that cancer can affect any part of the body, leading to numerous types of the disease.
Researchers suggest that there may be more than 100 types of cancer, depending on its nature and location. These include breast cancer, skin cancer, small cell lung cancer, small intestine cancer, soft tissue sarcoma, nasal cavity and paranasal sinus cancer, colon cancer, bile duct cancer, pancreatic cancer, prostate cancer, uterine cancer, bladder cancer, cervical cancer, fallopian tube cancer, testicular cancer, kidney (renal cell) cancer, ovarian cancer, thyroid cancer, urethral cancer, and many others.
Cancer and sports
Although there are treatments for cancer, and medical advancements have improved outcomes, these treatments—including chemotherapy, immunotherapy, hormone therapy, and surgery—are often expensive. While medical intervention remains crucial, lifestyle factors, particularly sporting activity, play a significant role in cancer prevention and management.
Luo H, Galvão DA, Newton RU, et al., in their study Sport Medicine in the Prevention and Management of Cancer, define sport as an activity requiring physical effort and skill, governed by predetermined rules and objectives. Sports often demand a combination of physical and physiological exertion, depending on movement components and forms of play.
Cancer Research UK, for instance, asserts that engaging in sports, especially those involving physical activity, can help manage cancer. The organisation highlights that moderate-intensity sports, such as brisk walking, cycling, and swimming, can assist in managing the disease. Additionally, vigorous-intensity activities, such as running, aerobics, netball, football, and fast cycling, are particularly beneficial in supporting cancer management.
In their study, Sport Medicine in the Prevention and Management of Cancer, conducted in 2019, Luo H, Galvão DA, Newton RU, et al., suggest that participating in structured sport programmes may serve as an alternative strategy to conventional clinic-based and community-based physical exercise programmes, allowing for wider implementation in cancer prevention and management.
The researchers state: “Physical inactivity is a major concern in cancer patients despite the well-established preventative and therapeutic effects of regular physical exercise. The potential of sport as an effective strategy in cancer prevention and management has received little attention. Based on the limited evidence available, participation in supervised, well-tailored sport programmes appears to be safe and feasible, offering an array of physical and psychological benefits. As with traditional exercise, the benefits derived from sport participation depend on the type of sport undertaken and its physical, physiological, motor, and cognitive demands.”
They further note: “Clinical trials have shown preliminary efficacy of prescribed sports activities, such as football, triathlon, wall climbing, and dragon boat racing, in patients with common types of cancer, predominantly prostate and breast cancer, on various supportive care outcomes. Therefore, we propose that structured sport programmes may serve as an alternative strategy to conventional clinic-based and community-based physical exercise programmes and could be implemented more widely in cancer prevention and management.”
Swimming reduces tumour
Meanwhile, a study conducted in 2022 by Li J, Liu L, Cheng Y et al., titled Swimming Attenuates Tumour Growth in CT-26 Tumour-Bearing Mice and Suppresses Angiogenesis by Mediating the HIF-1α/VEGFA Pathway, found that swimming reduced tumour growth.
“In this study, mice bearing tumours derived from CT-26 cells were randomly divided into control and swimming groups. The mice in the swimming group underwent physical training (swimming) for three weeks. Compared with the control group, swimming significantly reduced tumour volume and weight in CT-26 tumour-bearing mice,” the researchers reported.
Another study, Proportion of Cancer Cases Attributable to Physical Inactivity by US State, 2013–2016, conducted by Minihan, Adair K., Patel et al., and published in Medicine & Science in Sports & Exercise, the journal of the American College of Sports Medicine, quantified the relationship between physical activity and cancer incidence among adults aged 30 and older.
Using self-reported physical activity data from nearly 600,000 adults across the U.S., the researchers determined that 3 per cent of common cancers—including cancers of the kidney, colon, stomach, oesophagus, bladder, breast, and uterus—could be closely linked to inactivity. The study estimated that an average of 46,356 cancer diagnoses per year were attributable to inactivity. Stomach cancer was found to be the most closely tied to inactivity, with nearly 17 per cent of cases resulting from insufficient movement. The researchers suggested that if all Americans met or exceeded the recommended five hours per week of moderate physical activity, more than 46,000 cancer diagnoses each year might be prevented.
Reducing cancer risk
A professor at the Fred Hutchinson Cancer Research Centre in Seattle, Washington, USA, Dr Anne McTiernan, who is also the author of the book Cured: A Doctor’s Journey from Panic to Peace, emphasises the benefits of exercise in reducing cancer risk. Specifically, she recommends swimming.
McTiernan states: “Swimming is an excellent exercise that meets and exceeds our committee’s goals for cancer risk reduction. Plus, the risk of injury with swimming is lower than in many other sports, so people are less likely to be sidelined. If you want to reduce the chances of ever having to speak with an oncologist, get to the pool and start logging those laps. Hitting the target of five hours of activity a week is just a few swimming sessions away.”
Yet another study published in Oncogene in 2015 specifically highlighted that moderate swimming suppressed liver cancer. Conducted in China by Q-B Zhang, B-H Zhang, K-Z Zhang et al., the study, titled Moderate Swimming Suppressed the Growth and Metastasis of Transplanted Liver Cancer in a Mice Model: With Reference to the Nervous System, found that regular moderate swimming (8 minutes per day, 9 weeks) raised dopamine (DA) levels in the prefrontal cortex, reduced lung metastasis of transplanted liver cancer, and prolonged survival in a C57BL/6 mouse model.
The researchers state: “In nude mice orthotopically implanted with human liver cancer cell lines, DA treatment significantly suppressed growth and lung metastasis by acting on the D2 receptor (DR2). Furthermore, DR2 blockade reduced the suppressive effect of moderate swimming on liver cancer. Both moderate swimming and DA treatment inhibited the transforming growth factor-beta (TGF-β1)-induced epithelial-mesenchymal transition of transplanted liver cancer cells.”
Prevention, as the saying goes, is better than cure. Given the deadly nature of cancer and the high costs of medical treatment, incorporating swimming into one’s routine presents a multifaceted approach to cancer prevention and management. Its physical benefits, combined with mental health advantages, make it a valuable activity for those seeking to reduce cancer risk or manage treatment side effects. However, individuals should consult their healthcare team before starting any new exercise regimen to ensure it aligns with their specific health needs.
