Why weight loss in cancer patients what is it called?

Cachexia. Weight loss in patients with cancer is called cachexia. It is commonly due to chemicals called inflammatory cytokines that circulate in their bodies. One example is tnf Alpha (tumor necrosis factor), which is released by immune system cells.
Cachexia. In cancer, cells grow so fast that they use up energy and nutrients for their own uncontrolled growth. Hence weight loss. Also medications for cancer could contribute to this. It is called cachexia.