Losing muscle during cancer treatment

Is it inevitable or can we prevent it?

Kelly Grainger, Specialist Oncology Dietitian

Monitoring changes in body weight during treatment is important. Recently there has been a growing interest into how not only body weight but body composition, specifically proportions of lean tissue and fat mass, may be related to how well people tolerate cancer treatment and its effectiveness. Losing muscle mass – a condition known as sarcopenia – can significantly affect the tolerance of cancer treatment. Managing this condition is therefore imperative.

What is sarcopenia?

Sarcopenia is a medical term for ‘a progressive loss of lean body mass associated with an increased risk of adverse outcomes such as physical disability and reduced quality of life’. Lean body mass is the amount of weight you carry on your body that isn’t fat or bone.

From the time you’re born, to around the time you turn 30, your muscles grow larger and stronger. But at some point after this, you begin to lose muscle mass and function.

On average, people lose as much as 3% to 8% of their muscle mass per decade after the age of 30. By the time you’re 65, you might have lost 20-25% of your muscle strength, with a 30% decline per decade thereafter.

The natural loss of muscle mass that happens with age can be accelerated after a cancer diagnosis, due to the disease itself or the treatment for it. The loss of muscle mass experienced during cancer treat­ment has been shown to be significantly associated with cancer outcomes including overall survival, disease-free survival and treatment toxicity.

How does sarcopenia affect cancer treatment?

Studies have shown that sarcopenia is common in people with a range of cancers such as lung cancer, kidney cancer, oesophageal cancer, breast cancer, ovarian cancer and prostate cancer.

People who start cancer treatment with a low muscle mass, or who lose a significant amount during their treatment, are likely to experience more severe side-effects from their cancer treatment.

This may result in them needing to stop their treatment for a time, or receive a lower dose, which can ultimately affect how successful their treatment is.

Further research on how to prevent or reverse sarcopenia, and how such interventions might improve cancer treatment outcomes is vital.

How can we monitor body composition during treatment?

Almost every time you come to the LOC for treatment, you’ll be weighed. While it’s clearly important that we monitor any changes to your weight, the simplistic concept of body weight can actually be quite misleading. After all, many patients who remain the same weight throughout their treatment will report that their arms and legs feel thinner yet they are gaining weight around their tummy. This indicates that they’re losing muscle mass but gaining fat mass. These changes won’t be detected by weighing patients regularly.

In the research setting, we can use CT scans taken as part of routine clinical care, to accurately measure muscle mass and fat mass, and detect sarcopenia. However, this isn’t yet widely used in clinical practice. More sensitive measures of body fat and lean body mass that can be used in the clinic are needed and this is a current area of investigation.

Is it possible to treat sarcopenia during cancer treatment?

There’s plenty of evidence to suggest that sarcopenia is preventable or even reversible.

Nutritional treatment is likely to be most effective before you’ve lost a considerable amount of muscle mass, rather than at the point at which sarcopenia becomes severe. Tacking it early is essential, starting as soon as you’re diagnosed.

Loss of muscle mass can be caused by a variety of factors. You might be less able to do physical activity, for example, which can lead to you losing further muscle mass due to under-use, you may be getting inadequate levels of protein from your diet, you might have vitamin D deficiency or your body may be mildly inflamed – all of which can affect the health of our muscles. Holistic management strategies – treatments that aim to treat your whole body – should target each of these effects by offering a combination of physical activity support, nutritional advice and possibly pharmaceutical or nutraceutical interventions to reduce inflammation.

Physical activity

Exercise is the primary treatment for sarcopenia. International guidelines recommend a combination of aerobic and resistance exercise for 30 minutes, three to seven times per week.

Aerobic exercise is anything that involves moving your body’s large muscles repeatedly, such as running and swimming. When you do it, your body needs more oxygen and so your heart and lungs have to work harder. Resistance training or strength training – exercise that increases muscle strength and endurance with weights or resistance bands – has been shown to be useful for both the prevention and treatment of sarcopenia.

Exercise is the primary treatment for sarcopenia. International guidelines recommend a combination of aerobic and resistance exercise for 30 minutes, three to seven times per week.

Aerobic exercise is anything that involves moving your body’s large muscles repeatedly, such as running and swimming. When you do it, your body needs more oxygen and so your heart and lungs have to work harder. Resistance training or strength training – exercise that increases muscle strength and endurance with weights or resistance bands – has been shown to be useful for both the prevention and treatment of sarcopenia.

There’s plenty of evidence to suggest that sarcopenia is preventable or even reversible.

Nutritional treatment

There’s a range of nutritional interventions that can help to manage sarcopenia. These include the following.

My advice

Further research is required to assess the effectiveness of the above interventions using meaningful clinical measures of muscle mass, either alone or in combination, in larger populations of cancer patients. It’s likely that a combination of treatments will be most effective, using a mixture of physical activity and nutritional approaches.

Until we find these answers, the best advice we can give is to be physically active and to eat a balanced diet. This will help you to maintain or build up muscle mass, as well as lose fat, if necessary, to maintain your strength and function. It’s important to make these changes early, ideally immediately after you’re diagnosed with cancer, or after a long hospital stay.

If you would like further details about the exercise programmes or nutritional advice on offer at the LOC, contact the supportive services co-ordinator on 0207 317 2628 or email supportiveservices@theloc.com