Feelings of exhaustion for no known reason may be one sign that cancer is present, although that symptom on its own is not enough and could occur for a number of different reasons. Unfortunately, other significant symptoms may occur when the cancer has advanced. These are fluid on the lung, chest pain and breathlessness.
Angiosarcoma grows from cells that help construct the walls of blood vessels. An embolism travelling through the blood system can block a vein and cause pain in the heart. An embolism is a small piece of the tumour that breaks off and forms a small clot that blocks a blood vessel. Having explained all this, heart cancer is very rare. Most tumors in the heart are benign.