What is a cancer that spreads to other parts of the body called?

The term used to describe cancer that spreads from its original (primary) site to other parts of the body is metastatic cancer. This occurs when cancer cells break away from the primary tumor, travel through the bloodstream or lymphatic system, and form new tumors in different organs or tissues. This characteristic of spreading makes metastatic cancer more complex and often more challenging to treat than localized tumors, which remain confined to the area where they originated.

Metastatic cancer is an important concept in oncology because it signifies a more advanced stage of the disease, which may require a different approach in terms of treatment options, such as systemic therapies including chemotherapy or targeted therapy, rather than localized treatments like surgery or radiation that might be effective for tumors that have not yet spread.

Localizing cancer refers to tumors that have not spread beyond their original site, while benign cancer refers to non-cancerous tumors that do not invade surrounding tissues or metastasize. Malignant cancer encompasses all cancerous tumors, which can be locally invasive or metastatic, making it a more general term but not specific to the aspect of spreading in metastasis. Thus, metastatic cancer is the precise term for cancer that has disseminated throughout the body.