Cancer is the second most frequent cause of death worldwide; for an ageing population, will soon become the first, because most cases of cancer occur in older adults. The word “cancer” is applied to cover a wide range of different types of malignant tumours, which can develop in virtually every body tissue. The symptoms of cancer, or its clinical manifestations, are different for different kinds of body tissues or organs affected by cancer.
Cancer-related malnutrition is the immediate cause of death in 20 percent of cancer patients, and 8 percent to 84 percent of cancer patients show some effects of such malnutrition, which are associated with difficulties in some function or the other. The Quality of Life enjoyed by a patient depends on the interaction between the patient’s nutritional status, the symptoms of cancer and/or treatments, and other factors related to the disease or its treatment—a complex combination indeed.
The Impact Of Malnutrition
Malnutrition harms every system in the body, yet there is more to malnutrition than mere decline in nutritional status. Prolonged malnutrition, not eating enough for weeks at a time, changes – usually for the worse – not only metabolism, body composition, and body functions but also the mind. In other words, malnutrition, a disease by itself, makes the body prone to other diseases.
No matter what the underlying mechanism, cancer-related weight loss and nutritional wasting are visible effects with multiple dimensions that worsen patients’ well-being, their ability to tolerate the treatment prescribed for cancer, and prognosis, or the ultimate outcome. Specifically, weight loss lowers the body’s defences against malignant tumours and its ability to fight infections, makes the body more susceptible to post-operative complications, leads to greater disability, and increases the overall cost of care.
Malnutrition in Cancer Patients
Although many studies were undertaken in the early 20th century, malnutrition was poorly understood even by the end of that century. The most frequent visible effect of malnutrition in cancer patients is weight loss; if such loss amounts to more than 10 percent of a patient’s normal weight, the matter is indeed serious not only clinically but also for the ultimate outcome, because such drastic loss in weight loss in any patient – no matter what the disease – may worsen its ill effects and increase the chances of death.
Although malnutrition in cancer patients is held to depend on what tissue or organ has been affected by the cancer, whether a cancer patient will lose a great deal of weight are related to other factors such as the aggressiveness of the cancer (the stage of the cancer stage and the aggressiveness of cancer cells), the treatment (radiotherapy, chemotherapy, surgery), age, and such intervening emotional factors such as depression.
Cancer-Related Appetite Loss and Symptoms
Depending on the site of the cancer and the treatment, even the simple, mechanical act of eating may prove difficult and involve a variety of adverse symptoms including pain, difficulty in swallowing, vomiting, or diarrhoea. In the face of such problems, patients may develop a general aversion to food to escape from the problems.
Moreover, food aversion can be unrelated to any other symptom and appear even before the diagnosis of cancer. At times, the sheer mass of a tumour may restrict the amount that can be eaten. Lastly, the emotional impact of cancer by itself may precipitate depression or anxiety, both of which are known to cause loss of appetite.
The Importance of Adjuvant Nutrition
Nutrition is clearly and consistently associated with cancer and is one of the most significant risk factors for the development of cancer. Our research at the Faculty of Medicine of the University of Lisbon, conducted over 10 years, has involved patients with cancer of the head and neck, oesophagus, stomach, and colon/rectum.
Our results demonstrate, beyond any doubt, the importance of nutrition in cancer as essential to a patient’s well-being, the quality of Life, greater tolerance to treatments, improved prognosis, and longer survival in face of the devastating disease. These pioneering findings call for integration of nutrition into the treatment of cancer and the management of cancer patients.