Muscular strength and good physical fitness are linked to a significantly lower risk of death from any cause in people with cancer, finds a pooled data analysis of the available evidence, published online in the British Journal of Sports Medicine.

Tailored exercise to boost muscle strength and cardiorespiratory fitness in patients with cancer may help boost their chances of survival, suggest the researchers.

In 2022 alone, 20 million people were diagnosed with cancer worldwide, and nearly 10 million died from their disease-trends that are projected to increase in the coming decades, note the researchers.

And despite notable advances in cancer prevention, diagnosis, and treatment, the side effects of treatment, including those on the heart and muscles, can take their toll on survival, they add.

To inform potential options for extending survival in people diagnosed with cancer, the researchers set out to see if muscular strength and cardiorespiratory fitness might be associated with lower risks of death in these patients, and whether cancer type and stage might be influential.

They searched for relevant studies published in English up to August 2023 and included 42 in their pooled data analysis, involving nearly 47,000 patients (average age 64) with various types and stages of cancer.

Low muscle strength, using handgrip strength, was classified as either less than 13 kg to less than 25 kg in women, and from less than around 20 kg to less than 40 kg in men.

Cardiorespiratory fitness was assessed using either cardiopulmonary exercise testing (CPET) or the 6 minute walk test (MWT). 

The pooled data analysis of the study results showed that both muscular strength and cardiorespiratory fitness were significantly associated with the risk of death from any cause and specifically from cancer. 

Compared with those with poor muscle strength and low levels of cardiorespiratory fitness, those at the other end of the spectrum were 31%-46% less likely to die from any cause.

And this risk fell by a further 11% with each unit increase in muscular strength.

What’s more, this combination of strength and fitness was associated with an 8%-46% lower risk of death from any cause in patients with advanced cancer (stages 3 and 4), and a 19%–41% lower risk of death from any cause among those with lung or digestive cancers. 

And each unit increase in fitness level was associated with an 18% lower risk of death from cancer itself. 

“Our findings highlight that muscle strength could potentially be used in clinical practice to determine mortality risk in cancer patients in advanced stages and, therefore, muscle strengthening activities could be employed to increase life expectancy,” suggest the researchers.