Cancer patients are under the risk of weight loss and malnutrition due to the catabolic state caused by the tumor and treatment methods such as surgery, chemotherapy and radiotherapy. The changing metabolic state, inflammatory processes and cancer treatments that are associated with the catabolism generally increase the body's energy and nutritional needs, while the patient's appetite, nutrient intake and nutritional use affect the body in a negative way. In response to increased energy and protein requirements, reduced intake of nutrients and the failure to meet increased losses cause a negative energy and protein balance to be formed. As a result, cancer cachexia is an important problem that affecting the risk of mortality and morbidity, response to treatment and quality of life negatively. At this point, it is very important to evaluate the nutritional status of the patient from the diagnosis and to make the patient-specific nutritional plan and support when necessary.

Keywords: Cancer, Chemotherapy, Radiotherapy, Nutrition Treatment, Assesment of nutritional status