A tumour is an abnormal and excessive growth of body tissue that is uncoordinated with the other tissues and does not respond to the body's natural regulatory mechanisms.
Many people with cancer have problems with eating, complain of a lack of appetite or have difficulty swallowing food and fluids. As a result, our body is not sufficiently well nourished, and consequently we lose weight, feel weak and tire quickly. The disease itself plays a significant part here, but to a large extent this also happens when we undergo radiotherapy and (or) chemotherapy, or surgery – we then experience the side effects associated with the treatment.
Cancer causes inflammation in our body. Dividing cancer cells secrete cytokines – proteins that affect the growth, division and activation of cells involved in the immune response and of haematopoietic cells, and which can mimic the action of appetite-suppressing substances and increase the body's energy expenditure. At the same time, the tumour secretes factors that cause the breakdown of proteins (proteolysis) and fat tissue (lipolysis). These biochemical reactions contribute to a deterioration in the patient's nutritional status even when he or she is eating properly. The formation of cancer cells in organs involved in digestion and absorption causes disturbances and abnormalities in their function. In patients, this manifests itself as nausea, vomiting, bloating and diarrhoea after eating certain foods. Patients begin to feel an aversion to food and lose their appetite, which leads them to eat too few meals.
The location of the tumour is also of great importance, as it may make it difficult for the patient to eat. For example, cancer located in the mouth, throat or oesophagus can make swallowing food and fluids considerably more difficult.
Treatment and the side effects it sometimes causes, in the form of swallowing disorders (dysphagia, odynophagia), taste disturbances, loss of appetite, nausea and vomiting, are further factors that can lead to malnutrition in the patient. The most common therapies used to fight cancer are surgery, radiotherapy, chemotherapy, hormone therapy and immunotherapy. They are used on their own or, often, as so-called combined treatment – in combination with one another. Cancer therapy aims to destroy cancer cells in the body, but at the same time it damages healthy cells, especially the fastest-dividing ones, such as the cells of the oral mucosa, the gastrointestinal tract and the hair follicles. That is why, during oncological treatment, patients often experience side effects of therapy in the form of mouth ulcers, inflammation, nausea, vomiting, diarrhoea and hair loss. The nature and severity of the adverse effects of therapy depend largely on the type of cancer and its location, the stage of the disease, the type and duration of treatment, the doses of the drug and radiation, and the patient's age and general condition.
Treatment, the stress associated with the illness, the swallowing problems that sometimes occur and the side effects of therapy mean that patients do not eat the amount of food their body needs. Essential nutrients, especially an adequate amount of protein and fat, are needed to fight the disease and for treatment to be effective. Malnutrition in cancer patients means that post-operative wounds heal with more difficulty and more slowly, and their recovery period is prolonged. The patient tires more easily and more quickly. Often they are unable to complete their treatment – in the case of chemotherapy (and/or) radiotherapy, when blood parameters fall, the therapy must be stopped until the patient's general condition improves.
Below you will find advice on what to do to help yourself when you find out that you have to face cancer.
Let us remember – we can help ourselves and our loved ones.
Dr Ewa Chawińska, MD PhD