Individuals with cancer share many similar nutritional problems, regardless of the primary site of the malignant neoplasm. The presence of protein-calorie malnutrition is the most common secondary diagnosis in cancer and is frequently the cause of death. To date, the inability of health care professionals to halt or adequately control the severity of protein-calorie malnutrition in the individual with cancer indicates that the syndrome is more complex than inadequate ingestion of nutrients. The presence and severity of protein-calorie malnutrition in individuals with cancer cannot be attributed to one factor. The disease, treatment modalities, and complications of therapy all contribute to its development.