It may grow through the bile duct wall and spread out into surrounding tissue, usually the liver and nearby lymph nodes. It may also spread to other parts of the body, carried in the blood stream.

A tumour in the part of the bile duct leading to the gallbladder (the cystic duct) can spread to the gallbladder.

When cancer cells from a bile duct tumour settle in another part of the body and start growing there, it is called secondary cancer or metastasis.