Diets Debunked

Cancer is a complex and multifaceted disease, often accompanied by a range of debilitating symptoms and side effects. One of the most severe yet under recognised consequences of cancer is cachexia, a wasting syndrome that profoundly impacts patients’ quality of life and survival. Despite its prevalence, cachexia remains poorly understood by many, both within and outside the medical community.

What is cancer cachexia?

Cancer cachexia is a multifactorial syndrome characterised by severe weight loss, muscle wasting, and loss of appetite (anorexia). Unlike simple malnutrition, cachexia cannot be fully reversed by increasing calorie intake alone, which makes it very difficult for dietitian’s to treat. It is a systemic condition that affects the entire body, leading to a decline in physical function, significantly reduced muscle mass, reduced tolerance to cancer treatments, and increased mortality.

Cachexia is often described in three stages:

1. Pre-cachexia: Early signs such as minor weight loss and metabolic changes.
2. Cachexia: Significant weight loss (more than 5% of body weight), muscle wasting, and fatigue.
3. Refractory cachexia: A severe, irreversible stage where patients are unresponsive to treatment and have a very poor prognosis.

How does cachexia happen?

The mechanisms behind cancer cachexia are complex and involve a interplay of metabolic, inflammatory, and neuroendocrine changes.

1. Systemic inflammation: Tumours release inflammatory molecules called cytokines, such as interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α). These cytokines disrupt normal metabolic processes, leading to muscle breakdown and fat loss.
2. Altered metabolism: Cancer cachexia is marked by a hypermetabolic state, where the body burns calories at an accelerated rate. At the same time, the body’s ability to use nutrients efficiently is impaired, leading to muscle and fat depletion.
3. Muscle wasting: A key feature of cachexia is the breakdown of skeletal muscle. This occurs due to an imbalance between protein synthesis and degradation. Factors such as inflammation, insulin resistance, and reduced physical activity contribute to this process.
4. Loss of appetite: Many cancer patients experience anorexia, which exacerbates weight loss. This is partly due to the effects of cytokines on the brain’s appetite-regulating centres, as well as side effects of treatments like chemotherapy.
5. Tumour-derived factors: Some tumours produce substances that directly promote muscle wasting and fat loss. For example, certain cancers release proteins that interfere with muscle maintenance.

Because all of these factors are not just impacting appetite, but also significantly increasing calorie, protein and nutrition requirements and impacting how effectively the body uses these nutrients, preventing further wasting and weight loss in cachexia is very difficult. Often, minimising the wasting and muscle loss, rather than stopping it completely, is the only viable solution.

The impact of cachexia

Cancer cachexia has a devastating impact on patients’ lives. Patients will often find that they experience:

• Reduced quality of life: Patients often experience profound fatigue, weakness, and difficulty performing daily activities. This is generally due to the significant muscle loss they experience, which makes walking or even standing difficult to achieve, but also due to the inability to use calories and other nutrients efficiently, which causes fatigue in and of itself.
• Treatment complications: Cachexia can limit a patient’s ability to tolerate surgery, chemotherapy, or radiation, reducing the effectiveness of these treatments. Equally, these treatments can exacerbate some of the more unpleasant symptoms of cancer or cachexia, and so it can become a vicious cycle.
• Increased mortality: Cachexia is directly linked to shorter survival times. In some cancers, it is estimated to be the immediate cause of death in up to 20% of patients.

The physical decline caused by cachexia also takes a psychological toll, contributing to feelings of helplessness and depression in both patients and their families.

Which cancers are most commonly associated with cachexia?

Cachexia is most frequently observed in cancers of the pancreas, stomach, oesophagus, lung, and head and neck. The common thread between these cancers is they are often aggressive, and diagnosed at a later staging than other cancers. For many people, their diagnosis occurs because they have seen excessive weight and muscle loss, as the cancer cachexia has already taken hold.

• Pancreatic Cancer: Up to 80% of patients experience cachexia, often early in the disease course.
• Lung Cancer: Cachexia is common, particularly in advanced non-small cell lung cancer.
• Gastrointestinal Cancers: Cancers of the stomach and oesophagus are strongly associated with cachexia due to their impact on digestion and nutrient absorption.

However, cachexia can occur in any cancer type, especially in advanced or metastatic disease.

How do dietitian’s manage cancer cachexia?

Whilst it is generally very difficult to stop cancer cachexia in its’ tracks, dietitian’s will work with the patient to preserve as much muscle mass as possible and prevent any further weakening than what has already been experienced. This generally means:

1. A focus on high-calorie meals; those foods containing high amounts of fat tend to be preferred, as fat contains the most calories of all of the macronutrients at 9kcal/g. This could be including nut butters into smoothies, using high fat dairy and fortified milk as a base for milkshakes, adding more butter and oil to vegetables, and focusing on calorie dense food sources. These food sources can be healthy, such as oily fish and avocado, but oftentimes the thing that matters the most is getting the calories in, so dietitian’s may also recommend high calorie, typically unhealthy foods such as ice-cream, custard and fried foods.
2. Prioritising protein at every eating opportunity; whilst fat gives the calories, protein helps maintain the muscle mass. Getting protein wherever possible is key to maintaining muscle and preventing cachexia from worsening. Meat, fish, eggs and dairy, alongside veggie sources such as tofu, tempeh and soy milk are great ways to reduce the likelihood of cachexia worsening.
3. Eating little and often; This can be a good way to get more calories in overall during the day, and is especially important if there is pronounced cachexia and limited appetite found together. Grazing on high calorie snacks and drinks can often be easier to manage than 3 large meals.
4. Prioritising high-calorie fluids; fortified milk (4 tablespoons of milk powder mixed into a pint of water) can be used in teas and coffees, or can be used as a base for hot chocolates, milkshakes or smoothies. These higher calorie drinks can be easier to tolerate than solid food.
5. Fortifying foods wherever possible; constantly thinking about how you can add more calories into a food can go a long way. Cream in a soup with cheese sprinkled on top, buttered vegetables, a cheese sauce on some meat, extra butter on your bread can all go a long way.
6. Oral nutritional supplements; many people with cancer cachexia will require some high calorie, high protein ONS to help maintain their weight. These can be prescribed and used as food replacements if necessary.

Should these interventions be unsuccessful, enteral (tube) feeding may be considered.

A call for greater awareness and research

Despite its profound impact, cancer cachexia remains underdiagnosed and undertreated. There is currently no universally effective treatment, and management often focuses on alleviating symptoms rather than addressing the underlying causes. However, ongoing research into the mechanisms of cachexia offers hope for future therapies. Potential approaches include targeting inflammatory pathways, stimulating appetite, and preserving muscle mass.

For now, early recognition and multidisciplinary care are crucial. Nutritional support, physical therapy, and psychological counselling can help improve patients’ quality of life, even if the syndrome cannot be fully reversed.

Cancer cachexia is a devastating syndrome that underscores the systemic nature of cancer. It is not merely a side effect but a central aspect of the disease that demands greater attention from researchers, clinicians, and policymakers. By deepening our understanding of cachexia and developing effective treatments, we can improve outcomes for countless patients and their families.

If you or a loved one is affected by cancer, it’s important to discuss any unexplained weight loss or muscle wasting with your healthcare team. Early intervention can make a significant difference in managing this challenging condition.

Let’s shine a light on cancer cachexia—because no one should have to face this hidden burden alone.