Cancer: Malnutrition, Weight Loss

Malnutrition: Often risky weight loss

Malnutrition means that individuals are not provided with enough energy, protein or other nutrients. This can lead to dangerous weight loss in cancer patients (or other patients).

When do we speak of malnutrition?

When exactly one speaks of malnutrition was jointly redefined by international experts as part of the “Global Leadership Initiative on Malnutrition” (GLIM) in 2019. For this purpose, they established criteria regarding the patient’s appearance (phenotype) and the cause of the disease (etiology). For malnutrition to be present, it is sufficient if one phenotypic and one etiologic criterion each occur together – not all of the following criteria need to be present!

Phenotypic criteria:

Involuntary weight loss of at least five percent in six months.
Underweight as measured by a low body mass index (BMI) of less than 20 kg/m2 or less than 22 kg/m2 for those over 70 years of age
reduced muscle mass (sarcopenia)

Etiologic criteria:

reduced food intake of less than half for one week or a long-standing (chronic) digestive disorder that allows too few nutrients to be absorbed from food (malabsorption)

A cancer patient, for example, who involuntarily loses more than five percent of his or her weight within six months and at the same time eats too little for at least a week is considered malnourished.

Similarly affected by malnutrition are patients whose muscle mass is decreasing and who are also suffering from a smoldering inflammation in the body – even if those affected cannot measure these criteria themselves and may not even notice them. When muscle mass decreases, this does not necessarily result in weight loss.

In general, weight loss and underweight are not prerequisites for a diagnosis of malnutrition. Thus, cancer patients who are overweight or even obese can also be malnourished. Malnutrition is often overlooked in them!

Weight gain in malnutrition

Every cancer patient should be regularly checked for malnutrition. If necessary, remind your doctor! Especially if your weight changes in an unusual way (up or down), you should seek medical advice. It is important to find out the reason and correct it if possible.

How common is malnutrition in cancer?

Malnutrition in cancer is common: Depending on the type of tumor, stage of disease and age, one quarter to almost three quarters of all cancer patients are affected. Malnutrition is more common in patients with cancer of the digestive tract (gastric cancer, colorectal cancer, esophageal cancer, pancreatic cancer) and head and neck (e.g. thyroid cancer) than in patients suffering from breast or prostate cancer, for example.

Reasons for weight loss in cancer

Weight loss is a very common consequence of malnutrition. Generally, the body loses weight when the energy balance is negative for a long time. This can be due to several reasons:

The body is not getting enough nutrients (for energy and as building materials) in the diet.
The body cannot absorb nutrients properly due to problems in the digestive tract.
The body consumes more nutrients than it can reabsorb with food.

Since the energy gained in this way is just enough for the bare necessities and muscle mass is also reduced (sarcopenia), patients feel flabby and powerless – they move less, which further intensifies muscle loss and increases weight loss even more.

In addition, skeletal muscles are gradually reduced with age, even in healthy people. The technical term for this is age-associated sarcopenia. In addition, the body also loses skeletal muscle mass during chemotherapy. This chemotherapy-induced sarcopenia is about 1.6 times higher in men than in women.

Patients with esophageal cancer are particularly at risk for chemotherapy-induced loss of muscle mass.

Loss of appetite and change in taste

When cancer patients no longer want to eat, fears may be behind it. For example, some patients fear that the food they eat will also feed the tumor. They therefore restrict their eating in the hope of depriving the cancerous tumor of energy and thus “starving” it. But instead of harming the tumor, they primarily deprive themselves of the energy they desperately need for therapy and living with cancer.

Other anxieties and other mental stresses, such as grief, anger or depression, can also cause people with cancer to lose their appetite.

Sometimes malnutrition in cancer can also be attributed to the fact that taste perception is altered or reduced – either by the treatment or the tumor itself. Those affected then no longer taste the food or can hardly perceive different tastes. As a result, they eat less or nothing at all – malnutrition occurs.

Nausea and vomiting

Sometimes cancer treatment causes nausea and/or vomiting – especially chemotherapy. Affected patients have no appetite or cannot keep enough food down – they lose weight.

The severity of nausea and vomiting varies depending on the cancer drug administered. These side effects occur particularly frequently during treatment with the chemotherapeutic drug cisplatin. It also depends on the type of drug and its dosage whether nausea and vomiting occur immediately during treatment or hours or days later, and how long the symptoms last (hours to days).

Vomiting and nausea under cancer therapies are usually triggered directly by the respective drug. In addition, psychological factors (such as fear of nausea) can exacerbate symptoms in cancer patients.

Diarrhea

Dry mouth and inflamed oral mucosa

Dry mouth is a possible side effect of chemotherapy, immunotherapies and targeted therapies. Radiation to the head, which affects the salivary glands, can also result in dry mouth. In addition, inflammation of the oral mucosa (mucositis) can develop with sores or ulcers in the mouth. Both factors – dry mouth and inflamed oral mucosa – can make it difficult for sufferers to eat due to difficulty swallowing and pain, thus promoting malnutrition in cancer.

Unfavorable location of the tumor

The tumor itself can mechanically prevent cancer patients from eating enough. For example, if the cancerous tumor is located at the entrance to the stomach, it is difficult for food to pass by it and enter the stomach. In turn, a far-advanced colon cancer can block the intestine (intestinal obstruction) and make normal digestion impossible.

Organs removed in whole or in part

If cancer patients have had to have all or part of organs removed that are important for the absorption and digestion of food (e.g., esophagus, stomach), this promotes malnutrition.

Larynx, esophagus

Stomach

Patients who have had their stomach out and now have a replacement stomach may face the following problems:

They can only eat small amounts and are therefore quickly full.
The food “slips” through the stomach too quickly (tumbling emptying, dumping syndrome), which can lead to upper abdominal pain, diarrhea, circulatory problems or hypoglycemia.
The sphincter at the entrance to the stomach is missing, which is why food pulp can flow back into the esophagus. As a result, the esophagus becomes inflamed (esophagitis).
Fat digestion is often impaired.
Many patients can no longer tolerate milk sugar (lactose) (lactose intolerance).

Pancreas

The problems that occur after surgery on the pancreas depend on which part of the organ had to be cut out: If the head of the pancreas was removed, various digestive enzymes that the organ normally releases into the small intestine are missing. Without the pancreatic tail, the organ can no longer produce enough of the blood sugar-lowering hormone insulin. Affected individuals develop high blood sugar levels, may experience diarrhea and lose weight.

Intestine

Tumor cachexia

A special form of malnutrition is severe emaciation, known as tumor cachexia. Up to 85 percent of cancer patients are affected. In this case, the tumor uses its messenger substances to manipulate the metabolism and the immune system for its own purposes:

It ensures that metabolic products such as proteins are increasingly broken down – even if the person affected hardly moves (catabolic metabolic state). This causes the skeletal muscles throughout the body to shrink (sarcopenia). In addition, storage fats are broken down intensively, and the cells consume much more energy than usual. In addition, a persistent inflammation festers throughout the body (systemic inflammation). This also works against muscle building (anabolic resistance). The consequences of these processes are:

loss of appetite, disturbed taste and early feeling of satiety
persistent, involuntary weight loss
fatigue, listlessness and constant exhaustion (fatigue)
Reduction in performance
loss of muscle mass and strength (sarcopenia)
reduced quality of life

Stages of tumor cachexia

Tumor cachexia can be divided into three stages:

Pre-cachexia: This is the preliminary stage to cachexia. It is characterized by a weight loss of less than five percent, loss of appetite and metabolic changes.
Cachexia: Characterized by weight loss greater than five percent or BMI reduction of less than two percent, or muscle wasting and weight loss greater than two percent, as well as decreased food intake and systemic inflammation.
Refractory cachexia: “Refractory” means no longer amenable to therapies. Affected individuals show a severe loss of fat and muscle mass. Their life expectancy is less than three months.

After “blood poisoning” (sepsis), cachexia is the second leading cause of death in cancer patients. Early intervention is therefore extremely important – because once the final (refractory) stage is reached, therapy no longer promises success.

Terminal tumor cachexia

The conscious renunciation of food does not let the dying person starve agonizingly, but often even helps him to go in dignity! A forced intake of food would therefore be the wrong thing to do for the person concerned.

What are the consequences of malnutrition in cancer?

Malnutrition in cancer is problematic, because it…

demonstrably reduces the quality of life
@ causes or increases anxiety or depression, makes people listless and reduces their ability to concentrate,
makes muscle mass diminish, leads to fatigue, rapid physical exhaustion and weakness,
causes hair loss, dry and flaky skin,
makes more susceptible to infections,
reduces the functioning of red blood cells,
reduces cardiac output, disturbs heart rhythm and causes hypertension,
weakens the respiratory muscles,
makes cancer therapy less tolerable for the patient (stronger side effects),
reduces the tumor’s response to therapy,
promotes wound healing disorders after surgery,
worsens the prognosis for the course of the disease and thus reduces the chances of survival.

Recognize malnutrition

At the same time, it is also your doctor’s job to examine you regularly for malnutrition (screening) – regardless of whether you have noticed a rapid change in weight. With the help of a special protocol, he records your nutritional status, your disease situation and your age. If the doctor notices an increased risk of malnutrition during this screening, further analyses follow, which must also be repeated regularly:

Questions about your diet
Determination of your body composition (muscle and fat percentage) with the help of a computer tomography and/or a bioelectrical impedance analysis (BIA) – the latter measures the resistance (impedance) that the body opposes to an alternating current applied via electrodes
Measuring your muscle function with a hand strength test and/or a sit-to-stand test (getting up from a sitting position 5 times and sitting down again usually takes less than 16 seconds)
Measuring your physical fitness, for example, with a 400-meter walk test (usually can be done in less than six minutes) or a stride speed test (usually more than 0.8 meters per second)

Treatment of malnutrition in cancer

Treatment of malnutrition or tumor cachexia consists of three important pillars:

Identify and treat causes: First, it must be clarified where the malnutrition is coming from, and then these causes must be eliminated if possible. If, for example, side effects of the tumor therapy such as nausea or diarrhea are the reason for the malnutrition, these must be treated consistently (e.g., with medication).
Compensate for or stop weight loss: To compensate for weight loss, the malnourished body must receive sufficient energy from food in the future. However, in some situations, such as after removal of the stomach, weight gain is often difficult to achieve. Then, at least an attempt should be made to maintain the current weight.
Exercise muscles: Cancer patients need regular physical training to stop the breakdown of muscles and to be able to build up muscles again if possible.

The most important goal of treatment is for you to feel well again and gain quality of life.

Treat side effects of the tumor / therapy

Pain: If you have pain, be sure to talk to your doctor. There are several ways to treat pain adequately.

Nausea and vomiting: Nausea and vomiting can be managed well with appropriate medications called antiemetics. These are administered to cancer patients as an infusion via the vein (intravenously) as a preventive measure before chemotherapy. If necessary, a further dose can also be given (as an infusion or in tablet form).

Oral mucositis: Even before cancer therapy with drugs or radiation therapy, you should see your dentist to have any existing cavities and gum inflammation treated. Careful oral hygiene before, during and after therapy helps to prevent infections. If an infection nevertheless occurs in the mouth, the doctor can treat it with appropriate medication.

If these measures are not enough, your doctor may prescribe an anti-diarrheal medication. First, a so-called μ-opioid receptor agonist such as loperamide is tried. If this does not work sufficiently, an opiate-containing medication (such as tincture of opium) is used.

Caloric diet

As a cancer patient with malnutrition and weight loss, you urgently need nutrition therapy and/or regular nutrition counseling. A nutritionist or dietitian will work with you to analyze your current diet. Then you will receive an individualized nutrition plan and helpful tips. Often, this involves recommending exactly the opposite of what healthy people are advised to do (e.g., high-fat meals).

Only take nutritional supplements if you have discussed this with your doctor or dietician beforehand, so as not to negatively influence the cancer therapy!

Eat an energy-rich diet: The diet of cancer patients with malnutrition should be particularly rich in energy (provided there is no overweight). However, since cancer patients can often only eat small amounts at a time or have little appetite, the diet should contain as much fat as possible. This means: Whenever possible, you should enrich your meals with fat (e.g. vegetable oils, butter, cream, margarine, lard or bacon).

Caloric drinks: also drink diluted fruit juices, milkshakes, cocoa and sodas to give your body missing energy.

Consume plenty of protein (protein): Cancer patients especially need a lot of protein and many protein building blocks (amino acids). The recommended daily intake is 1.5 to 2 grams of protein per kilogram of body weight. For a person weighing 60 kg, this corresponds to 90 to 120 grams of protein per day. Meat, eggs, cheese, fish and shellfish provide plenty of protein, as do some plant products such as legumes, nuts and cereals. Animal proteins, however, are more beneficial for muscle building than vegetable ones.

Astronaut diet: In addition, to treat malnutrition in cancer, it may be useful to resort to drinking and supplementing foods (supplements), also called “astronaut diet.” These so-called supplements contain highly concentrated protein. They are available, for example, as protein powder that can be stirred into milk. Ready-made drinkable food that is taken as a snack is also helpful. It is also helpful to use protein concentrates before tumor surgery to prevent malnutrition after the operation.

Take a close confidant (friend, relative, etc.) with you to the nutritional consultation. He or she can help absorb the wealth of information and recommendations.

Artificial nutrition

When it is not possible to take in enough food naturally, nutrients must be artificially introduced into the body. This sounds scary at first, but it is vital. For some patients, artificial nutrition can even be a relief because it takes the pressure off them to eat a certain amount on a regular basis.

There are different forms of artificial nutrition:

enteral nutrition: in this case, all the nutrients needed are fed directly into the gastrointestinal tract via a tube, thus bypassing the mouth and throat.
parenteral nutrition: In this variant, the nutrients are introduced directly into the bloodstream (more precisely: into a vein) as an infusion. This type of artificial nutrition is used when the digestive organs are not sufficiently functional, for example because an inoperable tumor blocks the stomach or intestines.

Some cancer patients receive tube feeding (enteral nutrition) in addition to normal nutrition if they cannot absorb sufficient nutrients orally. Other patients must be fed only artificially (enteral and/or parenteral).

Physical activity

Endurance training (three times a week for at least 30 minutes each time)
Strength and resistance training (twice a week)

For frail patients, such training is difficult to manage. In this case, exercise in everyday life (walking, climbing stairs, etc.) is all the more important. Researchers have also achieved good results in these patients with so-called electromyostimulation. Here, the muscles are stimulated by electrical stimuli. This can also counteract the loss of muscle mass due to malnutrition in cancer.