Related conditions:
Fatigue, illness, malnutrition, infection, poor wound healing, reduced response to physiological and psychological stress, diminished physical and mental performance, inferior response to treatment, and shorter survival time are all complications of less than optimal weight in cancer patients.
Definition:
Weight loss is a reduction in body mass marked by a decrease in body fluid, fat, and muscle. Unintentional weight loss is involuntary weight loss.
Risk factors: Weight loss is one of the most common symptoms of cancer and a common side effect of many cancer treatments. Cancer, then, is a risk factor for weight loss. Weight loss itself is not a risk factor for cancer. In fact, many physicians and nutritionists believe that normal, controlled weight loss to reach optimal weight for health may help in preventing some cancers. However, unintentional rapid weight loss is a sign of a serious health problem and reason to see a doctor.
Etiology and the disease process: As body weight along with fluids, fat, and muscle decreases, normal physiological functions in cancer patients degenerate, contributing to a host of medical problems and even death. Being below optimal weight for health impedes treatment efforts.
Metabolic changes brought about by cancer can lead to a condition known as malabsorption. Patients affected by malabsorption may seem to consume enough food, but they do not absorb enough of the nutrients from the food and are unable to produce enough energy to fuel the body. This leads to a loss of fat and muscle, a wasting syndrome known as cachexia, which accounts for the emaciated look of some cancer patients.
Infection, fever, and hot flashes, common symptoms of cancer, or side effects of treatment increase body temperature. To cope with a rise in body temperature, the body needs increased energy, which is furnished by the calories in food. Patients need to increase their intake of calories by 10 to 13 percent for each degree above 98.6 degrees Fahrenheit (37 degrees Celsius).
A cancerous tumor also places demands on the body for added energy, which comes from the intake of extra calories. One theory suggests that the tumor benefits more than the patient does from the extra calories because the tumor is exceptionally efficient at using calories from food for its own growth. Moreover, a tumor can affect the appetite and the normal digestive process. Studies have shown that tumors produce chemicals that change the way the body makes efficient use of nutrients.
Chemical changes in the body are common with cancer. One theory is that cancer produces chemicals that lead to anorexia, the loss of desire to eat. Anorexia is common among cancer patients, however, and is linked to a number of factors associated with cancer and cancer treatment: changes in smell or taste, dry mouth, mouth sores and infections, difficulty in swallowing, nausea, diarrhea, constipation, and the psychological and emotional impact of cancer, which can lead to anxiety or depression. Anxiety and depression, in turn, can lead to anorexia.
To fully benefit from aggressive cancer treatments such as certain types of chemotherapy and radiation therapy, patients need stores of energy. Weight loss or less than optimal weight can diminish the effectiveness of treatment. To speed up normal tissue repair following aggressive cancer therapies, patients need sufficient calories and adequate amounts of the macronutrients: protein, carbohydrates, and fat. Poor nutrition weakens the body’s capability to tolerate certain treatments. For instance, a decrease in the dose of drugs or radiation to compensate for the patient’s low tolerance to a particular treatment could undermine the effectiveness of the treatment.
Incidence: Virtually every cancer patient can expect to suffer weight loss sometime during the course of the disease. Unintentional rapid weight loss is a common symptom of cancer. According to the American Society of Clinical Oncology in 2014, approximately 40 percent of cancer patients report unexplained weight loss at the time of diagnosis.
Symptoms: Weight loss is a symptom of many possible diseases, including cancer. The primary symptom in relation to cancer is a rapid, unexplained, reduction of body mass. The cause of such weight loss will be identified by analysis of other symptoms and test results.
Screening and diagnosis: Because weight loss leads to nutrition problems such as malnutrition or anorexia, diagnosing weight loss in cancer patients is done through nutrition screening and assessment. Screening identifies patients who may be at risk of complications from weight loss. Assessment establishes the overall nutritional status of a patient and helps doctors and nutritionists determine if the patient needs nutrition therapy. Nutrition screening and assessment are done before cancer treatment begins. Finding and treating nutrition problems in the early stages of the disease can improve the patient’s response to treatment and chance of recovery.
Nutrition screening is done by gathering information about the patient such as the following:
- Changes in weight over the past six months
- Changes in the amount and types of food the patient normally eats
- Problems that affect eating such as dry mouth, mouth sores, diarrhea, constipation, and changes in taste and smell
- The patient’s ability to reason, walk, and perform normal daily activities
- The patient’s perceived quality of life
Nutrition assessment also involves a complete physical exam. The examining physician checks for general health and signs of disease, along with fluid buildup in the body and the loss of fat or muscle. Nutrition assessment and monitoring, done by both doctors and nutritionists, continue throughout treatment of cancer.
Treatment and therapy: Preventing weight loss or encouraging weight gain is a major part of cancer treatment. Before actual treatment of the cancer, doctors treat any complications that may arise from weight loss. Drug therapy and medical nutrition therapy help patients gain or maintain a healthful weight, along with stores of energy, to better battle the cancer.
Drugs are used to relieve both symptoms of weight loss and side effects of treatment. The drugs are meant to achieve the following:
- Prevent nausea, vomiting, or diarrhea
- Promote bowel movements (laxatives)
- Relieve pain
- Prevent infections
- Heal sores in the mouth
- Stimulate saliva
- Encourage the action of pancreatic enzymes, proteins released by the pancreas that help break down food during digestion and create energy for the body
- Battle anxiety or depression
Medical nutrition therapy is a major component of cancer treatment. Depending on the condition of the patient and the stage of the cancer, medical nutrition therapy involves one of three types of nutrition: oral, enteral, and parenteral.
Oral nutrition is nutrition taken by mouth. This includes the normal intake of food, special diets prescribed by nutritionists, and nutritional supplements, including beverages and formulas, to build and maintain healthful nutrition levels.
Enteral nutrition is providing nutrients through a tube placed in the nose, stomach, or small intestine. Tube feeding is for patients who do not meet their nutritional needs from food and beverages and who do not have problems with vomiting or diarrhea. Tube feeding can be used to supply supplements to a patient’s diet or as the only source of nutrition.
Parenteral nutrition also known as hyperalimentation or total parenteral nutrition (TPN) delivers nutrients intravenously, through a blood vein, bypassing the digestive system. It is for patients who are unable to absorb nutrients through the gastrointestinal tract because of continual vomiting or severe diarrhea and for those undergoing high-dose chemotherapy or radiation and bone marrow transplantation. It is possible for patients to receive all the vitamins, minerals, protein, and calories they need through total parenteral nutrition.
Prognosis, prevention, and outcomes: Studies have shown that maintaining nutritional health improves the chances of survival from cancer. However, maintaining a healthful weight is no guarantee that cancer can be prevented or successfully treated. Too many other factors are involved. Often the cancer eventually overwhelms the entire system. During the later stages of cancer, sometimes the best treatment for patients is to allow them to eat what they want and to preserve the more pleasant and social aspects of eating.
Argilés, Josep M., et al. "Cancer Cachexia: Understanding the Molecular Basis." Nature Reviews Cancer 14.11 (2014): 754–62. Print.
Fearon, Kenneth C., Anne C. Voss, and Deborah S. Hustead. “Definition of Cancer Cachexia: Effect of Weight Loss, Reduced Food Intake, and Systemic Inflammation on Functional Status and Prognosis.” American Journal of Clinical Nutrition 83.6 (2006): 1345–50. Print.
Ko, A., E. H. Rosenbaum, and M. Dollinger. Everyone’s Guide to Cancer Therapy: How Cancer Is Diagnosed, Treated, and Managed Day to Day. 5th ed. Kansas City: Andrews, 2007. Print.
LaMantia, Jean, and Neil Berinstein. The Essential Cancer Treatment Nutrition Guide and Cookbook. Toronto: Rose, 2012. Print.
Langius, Jacqueline A. E., et al. "More Than 10% Weight Loss in Head and Neck Cancer Patients during Radiotherapy Is Independently Associated with Deterioration in Quality of Life." Nutrition & Cancer 65.1 (2013): 76–83. Print.
McIlwain, Harris H. The Fifty-Plus Wellness Program. Hoboken: Wiley, 1991. Print.
No comments:
Post a Comment