The stronger the muscles in cancer patients, the better their chances of survival

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

Individualized exercise aimed at improving muscle strength and cardiorespiratory fitness in patients with cancer may help increase their chances of survival, researchers suggest.

Globally, 20 million people were diagnosed with cancer in 2022 alone, and nearly 10 million died from the disease. This trend is projected to increase in the coming decades, the researchers said.

Despite notable advances in cancer prevention, diagnosis and treatment, side effects of treatment, including effects on the heart and muscles, can negatively impact survival rates, they add.

To gain knowledge about ways to improve survival in people diagnosed with cancer, the researchers sought to determine whether muscle strength and cardiorespiratory training might be associated with a lower risk of death in these patients, and whether cancer type and stage might affect survival.

They searched for relevant trials published in English up to August 2023 and included 42 of them in an analysis of pooled data involving about 47,000 patients (average age 64 years) with different types and stages of cancer.

Low muscle strength (hand grip strength) was categorized as less than 13 kg to less than 25 kg in women and less than 20 kg to less than 40 kg in men.

Cardiorespiratory fitness was assessed by cardiopulmonary exercise test (CPET) or 6-minute walk test.

A pooled analysis of the study results showed that both muscle strength and cardiorespiratory fitness were significantly associated with the risk of death from any cause and, in particular, cancer.

Compared to patients with poor muscle strength and low cardiorespiratory fitness, those at the other end of the spectrum had a 31% to 46% lower risk of death from any cause.

And with each one-unit increase in muscle strength, this risk was reduced by an additional 11%.

Moreover, this combination of strength and fitness was associated with an 8-46% reduction in the risk of death from any cause in patients with advanced cancer (stages 3 and 4) and a 19-41% reduction in patients with lung or digestive tract cancer.

And each one-unit increase in fitness level was associated with an 18% reduction in the risk of dying from cancer.

“Our results suggest that muscle strength can be used in clinical practice to determine mortality risk in patients with advanced cancer, and therefore muscle-strengthening exercise can be used to increase life expectancy,” the researchers said.