Clinical Nutrition

Lesson 31: Cancer

Impact of tumor on Host Metabolism

Malnutrition is a consequence of cancer and results due to the cancer itself or its therapy. The impact of the tumor on the host metabolism leads to cachexia and impaired immune function.

• Protein metabolism: Cancer causes increased turnover of whole body protein as well as increased rate of protein synthesis in the liver. However skeletal muscle is not only degraded more but also synthesized less. The tumor has the capacity to retain nitrogen and increase its weight while the rest of the body is wasting.
• Fat metabolism: More fat is metabolized and the rate of lipolysis is higher for patients with progressive disease. The plasma concentration of free fatty acids also increases. Fat is oxidized and total body fat decreases in the patient.
• Glucose metabolism: Glucose metabolism is altered in the disease condition. Glucose intolerance, insulin sensitivity and decreased responsiveness to insulin are commonly seen.