1. Cancer pain: Cancer cells can invade surrounding tissues and organs, causing severe pain. Advanced stages of cancer can lead to unbearable pain and a condition called "painful death". 

2. Organ failure: Without proper treatment, patients may lose significant weight and suffer from severe malnutrition. This can eventually lead to multiple organ failure and death.

 3. Infections: Infections can worsen the condition and increase the risk of developing chronic diseases.

Ultimately, multiple organ failure and infections can cause death.