The review was carried out by researchers at the University of Hong Kong and funded by World Cancer Research Fund (WCRF). The results will be presented at the NCRI Cancer Conference in Liverpool today (Tuesday).
The researchers reviewed 31 published randomised controlled trials to look at the effect of physical activity interventions – programmes where people are encouraged to be more active – on several factors, including quality of life, and the chances of cancer survival and recurrence.
While there was not enough good quality evidence on the effect of being active on cancer survival and recurrence to draw firm conclusions, the researchers found significant evidence that physical activity interventions led to a lower body mass index (BMI) and to an increase in lean body mass.
The study also found a link between functional capacity – a combination of measures such as strength, stamina and mobility – and physical activity, including better performance in six-minute walking tests.
Dr Judy Ho, the lead researcher for the project, said: “These results suggest that being physically active following cancer treatment is a good way of maintaining a healthy weight and of maintaining fitness levels.
“The strength of evidence is quite strong so this gives cancer survivors a good reason to increase their physical activity levels.”
Dr Panagiota Mitrou, Deputy Head of Science for WCRF, said: “We recommend cancer survivors are regularly as physically active as their condition allows and this study adds further evidence that this is worth doing.
“But the lack of quality evidence on whether physical activity affects risk of cancer recurrence highlights the fact that cancer survivors do not have access to the same quality of advice as the rest of the population.
“This is why there needs to be more research in this area and we have identified it as one of our priority areas. We recently announced plans for the biggest ever review of the evidence on breast cancer survivorship.”
Dr Jane Cope, Director of the NCRI, said: “Cancer survivors sometimes ask what they can do themselves to help manage their condition and improve well-being. Now we have evidence that something as simple and inexpensive as physical activity can have a real benefit.”
Notes to editors:
- • 63% of the studies looked at breast cancer survivors, with the rest looking at other types of cancer.
- • Randomised controlled trials avoid many of the types of bias that can be found in other studies. Controlled trials are often called the scientific ‘gold standard’. This can be true in many situations, but for physical activity interventions the results may be compromised because the people taking part will know whether they are doing physical activity or not.
- • One of the problems the researchers faced was that the different studies had recorded results in different ways. The researchers have highlighted the need for standardising the way future studies are carried out to make it easier for future reviews of the evidence to collate the results.
World Cancer Research Fund (WCRF) raises awareness that cancer is largely preventable and helps people make choices to reduce their chances of developing the disease.
This includes research into how cancer risk is related to diet, physical activity, and weight management, and education programmes that highlight the fact that about a third of cancers could be prevented through changes to lifestyle. For more information on the charity’s work, visit www.wcrf-uk.org
The WCRF report, called Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective, was launched in November 2007 and is the most comprehensive report ever published on the link between cancer and lifestyle. For more information, visit www.dietandcancerreport.org