Comment on: Physical activity for woman with breast cancer after adjuvant therapy

Life after breast cancer: may physical activity be of help? 

Breast cancer is worldwide the most prevalent cancer in women. Women surviving breast cancer are not only at risk of recurrence and reduced life expectancy, but undergo physical and psychological changes caused by both cancer and its treatment. Regular physical activity has been reported to  reduce the rates of cancer recurrence and mortality, possibly due to improved hormonal response and to better weight control. Current recommendations for breast cancer survivors include returning to normal daily activities as quickly as possible and engage in 150 minutes per week of moderate-intensity aerobic activity.

Are these recommendations grounded on solid evidence? 

This Cochrane review summarizes the current evidence on the effects of physical activity on breast cancer recurrence, mortality, physical and mental health and quality of life in women with breast cancer who completed active cancer treatment. 
Physical activity (e.g. walking, cycling, dancing) alone or combined with resistance training, was compared to "usual care" or "no physical activity" or "placebo". Due to some methodological limitations, the quality of this evidence was rated from very low to moderate.
The first important, though somehow disappointing, result is that the Authors could not find any study investigating the effects of physical activity after cancer on risk of recurrence or dying from breast cancer or any other cause. Further, no benefit of physical activity was found for perceived health, ability to sleep, pain, sexual functions, body mass index, waist-to-hip girth ratio, and bone health of the upper and lower spine or hip. 
On the other hand, the good news is that those women who performed regular physical activity after treatment for breast cancer experienced greater positive changes over the intervention period in terms of quality of life, views on their emotional health and physical ability, social function, feelings of worry, stamina, physical activity  levels, body fat, and strength of muscles. Small improvements in feelings of tiredness, cardiorespiratory fitness and self reported physical activity were also sustained for three months or longer after completing the physical activity  intervention. 

Is physical activity safe?

Only few minor adverse events of physical activity and no negative effect were reported. Different types of exercises were associated to different benefits: for instance aerobic exercise improved views on perceived emotional health and physical ability, whereas resistance training resulted in greater improvement in muscle strength. 
In conclusion physical activity interventions for women who completed breast cancer treatment are safe and may provide small-to-moderate beneļ¬cial effects on some aspects of physical and mental health and of quality of life.
Higher quality evidence might determine the optimal combination of physical activity needed to improve breast cancer related outcomes.
Women who completed active treatment for breast cancer should keep exercising and being active!

Comment by Francesca Cecchi