Lets say someone goes to the doctor: The doctor sees tumors in the lungs and in the liver. Why does the doctor know that its liver cancer that spread to the lungs and not lung cancer that spread to the liver?

Question

Lets say someone goes to the doctor: The doctor sees tumors in the lungs and in the liver. Why does the doctor know that its liver cancer that spread to the lungs and not lung cancer that spread to the liver?

In: 1592

Answer 1

Generally cancer spread follows the pathway of the blood that flows through the original tumor. the liver receives majority of its blood supply from the gut, therefore majority of secondary liver cancer originates in the gut. Additionally, all blood that leaves the liver, gets sent to the lungs, and so primary liver cancer often metastasises to the lungs first.